HUD optical aberration correction method and related equipment

Abstract

The invention relates to the technical field of head-up display, in particular to an HUD optical aberration correction method, system and device and a vehicle. The correction method comprises the following steps: generating a light beam through an LED light source or a laser light source, and adjusting the brightness and color parameters of the LED light source or the laser light source through a control circuit so as to adapt to different display requirements and environmental conditions; and the light beam is preliminarily shaped and collimated by the light beam shaping element until a proper divergence angle and a proper light spot size are met so as to meet the requirements of a coupling element. According to the invention, the light beam emitted by the light machine is subjected to one-dimensional or two-dimensional pupil expansion through the optical waveguide, and then view field expansion and aberration correction are carried out through the free-form surface mirror, so that the problems of large size, limited view field angle, small eye box range and insufficient imaging definition in the prior art are effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of head-up display, and in particular to a HUD optical aberration correction method, system, device and vehicle. Background Art

[0002] Head-Up Display (HUD) projects car-related information directly into the driver's field of vision, reducing the frequency of looking down at the instrument or central control screen during driving, thereby improving driving comfort and safety. Existing HUD technology has many limitations. For example, C-HUD uses external transparent glass for multiple refractions and reflections. Although it can form a distant virtual image, the device is large and difficult to miniaturize. Although W-HUD uses the front windshield as the working surface of the optical system and can provide a farther virtual image distance, it still needs to be improved in terms of field of view (FOV), eyebox range, imaging distance and display clarity. Although AR-HUD can provide long-distance virtual images and combine them with real scenes, it performs poorly in image quality optimization and eyebox adjustable range. In addition, most traditional HUD optical systems use complex separate optical components, which result in large size, heavy weight, and difficulty in large-scale market promotion and application. Although the HUD system in the existing technology has solved the volume problem to a certain extent, it still has obvious deficiencies in optical aberration correction, color uniformity and adjustable range of the eye box, and needs to be further optimized to meet the requirements of modern applications for miniaturization, high image quality and high performance. Summary of the invention

[0003] The present invention provides a HUD optical aberration correction method, system and device to solve the technical problems of large volume and limited field of view of the HUD optical system.

[0004] The technical solution of the present invention to solve the above technical problems is as follows: In one aspect, a method for correcting HUD optical aberration is provided, the steps of the correction method comprising: Generate a light beam through an LED light source or a laser light source, and adjust the brightness and color parameters of the LED light source or the laser light source through a control circuit to adapt to different display requirements and environmental conditions; The light beam is initially shaped and collimated by a beam shaping element until a suitable divergence angle and spot size are met to meet the requirements of the coupling element; The light beam enters the optical waveguide through an incoupling region having a grating structure, and the grating structure deflects the light beam so that the light beam is transmitted by total reflection in the optical waveguide until it reaches an outcoupling region; The coupled light beam coupled out from the optical waveguide passes through a free-form mirror to form a correction light beam for expanding the field of view and correcting aberrations. The free-form mirror flips according to the eye box adjustment range to ensure clear imaging at different eye positions of different drivers. The corrected light beam is reflected through the windshield into the driver's field of vision to form a navigation virtual image, so as to present navigation information on the road ahead to the driver; The control circuit detects environmental information, user input instructions and the internal state of the system in real time, and dynamically adjusts aberration correction parameters, light source parameters and image display parameters to optimize the display effect.

[0005] Furthermore, the coupling region grating structure of the optical waveguide is designed according to the following relationship: ; Among them, θ0 is the deflection angle of the incident light of the grating, θ1 is the deflection angle of the outgoing light of the grating, is the incident light tilt angle of the grating, is the tilt angle of the grating output light, m ​​is the diffraction order, λ is the wavelength of light, d is the grating constant, and n is the refractive index of the incident medium.

[0006] Furthermore, the grating structure is a surface relief grating or a volume holographic grating, and the grating structure includes a one-dimensional grating, a two-dimensional grating or a super grating.

[0007] Furthermore, the light beam after passing through the diffraction waveguide satisfies that the propagation angle of the light in the waveguide is greater than the Brewster angle: ; Where α is the propagation angle of the light in the waveguide, n b is the refractive index of the optical waveguide substrate, 1.4≤n b ≤2.8; The optical waveguide substrate is made of glass, resin or organic polymer crystal, and the thickness of the optical waveguide substrate is d b , 0.5mm≤d b ≤5mm.

[0008] Furthermore, the flip angle of the free-form surface mirror is calculated by the following formula: ; Among them, θ flip is the flip angle of the free-form mirror, h eye is the height of the driver's eyes, h pivot is the rotation axis height of the free-form mirror, d mirror is the distance between the free-form mirror and the windshield.

[0009] Furthermore, the flip angle of the free-form mirror is adjusted in real time according to the driver's body posture and eye position to ensure that drivers of different heights and body shapes can clearly see the HUD information.

[0010] Furthermore, during the formation of the navigation virtual image, the brightness and color balance of the light beam are adjusted in real time by the control circuit to adapt to different ambient lighting conditions and ensure the visual effect of the image.

[0011] On the other hand, a HUD optical aberration correction system is provided, for implementing the HUD optical aberration correction method as described above, the correction system comprising: An optical machine, which includes a high-brightness LED or laser light source, for generating a light beam and adjusting the brightness and color parameters of the light beam, for providing a clear, bright and colorful image; An optical waveguide, comprising an incoupling region and an outcoupling region, wherein the incoupling region has a grating structure and can deflect a light beam to perform total reflection transmission in the optical waveguide; An aberration correction element, comprising a free-form surface mirror, for expanding the field of view and correcting the aberration of the light beam coupled out from the optical waveguide, wherein the free-form surface mirror flips the lens angle around the rotation axis according to the eye box adjustment range to achieve clear imaging within a large eye box range; A windshield, used to reflect the corrected light beam to form a navigation virtual image; A control circuit, connected to and controlling the optical waveguide element, the aberration correction element, the light source system and the image generation unit, for controlling and operating the correction system; The aberration correction element further comprises: Binocular parallax correction module, used to optimize binocular parallax; A distortion correction module, used to correct the distortion in the optical system; The MTF optimization module is used to optimize the modulation transfer function of the correction system to improve the resolution and clarity of the image.

[0012] On the other hand, a HUD optical aberration correction device is provided, the correction device includes the HUD optical aberration correction system as described above, and the correction device also includes a naked-eye 3D implementation system, which is used for naked-eye 3D display by integrating a multi-layer optical waveguide structure and optical components in the optical waveguide element.

[0013] In another aspect, a vehicle is provided, the vehicle comprising the HUD optical aberration correction device as described above, and the vehicle further comprising: The front windshield serves as a display surface of the correction device and is used to reflect the light beam to form a navigation virtual image; The control circuit is used to detect environmental information, user input instructions and the internal state of the system in real time, and dynamically adjust aberration correction parameters, light source parameters and image display parameters to optimize the display effect.

[0014] The beneficial effects of the present invention are: The present invention effectively solves the problems of large volume, limited field of view, small eye box range and insufficient imaging clarity in the prior art by passing the light beam emitted by the optical machine through an optical waveguide to perform one-dimensional or two-dimensional pupil expansion, and then using a free-form surface mirror to expand the field of view and correct aberrations.

[0015] Specifically, the present invention utilizes a multi-layer optical waveguide structure and a mature free-form mirror processing technology to achieve a miniaturized and compact design of the system, reducing the volume by more than 50%, reducing the weight by more than 50%, and improving the flexibility of the device. The free-form mirror can not only effectively expand and collimate the light beam, but also can be flipped according to the eye box adjustment range, ensuring that drivers in different driving positions can clearly see the HUD information. By controlling the circuit to adjust environmental information, user input and system status in real time, the present invention can dynamically optimize aberration correction parameters, light source parameters and image display parameters, further improving the clarity, contrast and color accuracy of the image.

[0016] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Flow chart of a method for correcting HUD optical aberrations in one embodiment of the present invention; Figure 2 It is a schematic diagram of the principle of the present invention; In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. Optical machine; 2. Optical waveguide; 3. Free-form mirror; 4. Car windshield; 5. Human head model. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The term "comprise" and any variation thereof in the specification and claims of the present application are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units need not be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. In addition, the use of "and / or" in the specification and claims to indicate at least one of the connected objects, such as A and / or B, means including A alone, B alone, and A and B.

[0020] In the embodiments of the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0021] The present invention provides the following preferred embodiments: Embodiment 1 In order to solve the problems of large volume, limited field of view, small eye box range and insufficient display clarity in the existing HUD system, this embodiment proposes a HUD optical aberration correction method based on optical waveguide. Specifically, this embodiment achieves efficient operation and high-quality image display of the optical waveguide HUD system by optimizing the design of light source, beam shaping, grating structure and free-form mirror.

[0022] like Figure 1 As shown, the steps of the correction method include: S100, generating a light beam through an LED light source or a laser light source, and adjusting the brightness and color parameters of the LED light source or the laser light source through a control circuit to adapt to different display requirements and environmental conditions.

[0023] S200, the light beam is preliminarily shaped and collimated by the beam shaping element until it meets the appropriate divergence angle and spot size to meet the requirements of the coupling element.

[0024] S300, the light beam enters the optical waveguide through the coupling-in region having the grating structure, and the grating structure deflects the light beam so that it is transmitted by total reflection in the optical waveguide until it reaches the coupling-out region.

[0025] S400, the coupled light beam coupled out from the optical waveguide passes through the free-form mirror to form a correction light beam for expanding the field of view and correcting aberrations. The free-form mirror flips according to the eye box adjustment range to ensure clear imaging at different eye positions of different drivers.

[0026] S500: The correction light beam is reflected through the windshield into the driver's field of vision to form a navigation virtual image, so as to present navigation information on the road ahead to the driver.

[0027] S600, detecting environmental information, user input instructions and internal status of the system in real time through the control circuit, and dynamically adjusting aberration correction parameters, light source parameters and image display parameters to optimize display effects.

[0028] In this embodiment, the optical machine uses a high-brightness LED light source or a laser light source. These light sources have high luminous efficiency and color rendering, and can provide clear and bright images under different environmental conditions. The brightness and color parameters of the light source are dynamically adjusted by the control circuit to adapt to different display requirements. For example, during the day or in a strong light environment, the control circuit can adjust the brightness of the light source to avoid glare to the driver while maintaining clarity; at night or in a low light environment, the control circuit can appropriately reduce the brightness to reduce light pollution and energy consumption.

[0029] Furthermore, the light beam generated by the LED light source or the laser light source is initially shaped and collimated by a beam shaping element. The beam shaping element may be a lens group or a reflector group, and its purpose is to make the light beam have a suitable divergence angle and spot size to meet the requirements of the coupling element. It should be understood that the design of the beam shaping element takes into account the characteristics of the optomechanical light source and the entrance size of the optical waveguide to ensure that the light beam can achieve high-efficiency coupling when entering the optical waveguide.

[0030] Furthermore, the light beam enters the optical waveguide through a coupling region having a grating structure. The grating structure can be a surface relief grating or a volume holographic grating, which functions to deflect the light beam so that it is transmitted by total reflection in the optical waveguide.

[0031] Furthermore, conventional field of view expansion mostly uses Fresnel lenses, while in this embodiment, the light beam coupled out from the optical waveguide is subjected to field of view expansion and aberration correction through a free-form surface mirror. The use of Fresnel lenses will cause Fresnel fringes in the imaging, which will affect the imaging effect and cause visual discomfort; free-form surfaces are smooth surfaces with better imaging effects. Specifically, Fresnel lenses are prone to Fresnel fringes when imaging. First, due to the special concentric ring-shaped structure of the lens, the light is refracted and diffracted differently, resulting in optical path difference, and light waves interfere to form light and dark fringes; second, the processing accuracy of the lens is limited, and the ring-shaped size, shape error and surface roughness will change the propagation of light and cause additional interference; third, the good coherence of the light source or the difference in refraction of light of different wavelengths will enhance the interference effect; fourth, the temperature change and mechanical stress in the environment cause the lens to deform, change the light path and optical path difference, and also promote the generation of Fresnel fringes. The Fresnel pattern produced by the Fresnel lens during imaging will cause the image seen by the observer to appear light and dark stripes, reduce the image clarity and contrast, interfere with the observation of the imaging subject, make it difficult to distinguish details, affect the visual effect, make the information transmission inaccurate, and cause visual discomfort and cognitive bias. The free-form surface mirror is a smooth surface. Because it does not have the special structure of the concentric ring belt of the Fresnel lens, the light is reflected or refracted more regularly on its continuous smooth surface. It is mainly based on the continuous surface to change the propagation of light, follow the conventional optical laws, and avoid irregular interference of light during design and manufacturing, so it will not produce Fresnel patterns and have a better imaging effect. The free-form surface mirror does not produce Fresnel patterns, which can bring a clear and pure imaging experience to the observer. The image is free of interference from stray lines, the details are clearly visible, and the color reproduction is accurate. Whether it is watching the scene or the image, it is more realistic and natural, the visual experience is comfortable, and it can greatly enhance the concentration and immersion of observation.

[0032] Furthermore, the design of the free-form mirror allows it to flip according to the eye box adjustment range to adapt to the eye position of different drivers. It is understandable that the flip angle of the free-form mirror can be adjusted according to specific application requirements and the user's sitting posture to ensure that each driver can see clear HUD information within a comfortable field of view. This design not only improves the user experience, but also reduces visual fatigue caused by frequent adjustments to the head or body posture.

[0033] Further, the corrected light beam is reflected through the windshield into the driver's field of vision to form a navigation virtual image. As the final reflective surface, the windshield can accurately reflect the light beam to the driver's eye position to ensure clear display of navigation information. It should be understood that the reflection angle and reflection efficiency of the windshield are carefully optimized to reduce light loss and improve image quality.

[0034] Furthermore, the control circuit detects environmental information, user input instructions, and the internal state of the system in real time, and dynamically adjusts the aberration correction parameters, light source parameters, and image display parameters based on this information to optimize the display effect. For example, the control circuit can monitor the ambient light intensity in real time and adjust the brightness of the light source accordingly; monitor the user's sitting posture and head position and adjust the flip angle of the free-form mirror; monitor the internal temperature of the system and adjust the working state of the light source to ensure that the best display effect can be provided under various conditions.

[0035] The benefit of this embodiment is that by optimizing the design of the optical light source, beam shaping, grating structure and free-form mirror, the efficient operation and high-quality image display of the optical waveguide HUD system are achieved. The flip design of the free-form mirror increases the observation range of the eye box, ensuring that different drivers can see clear HUD information within a comfortable field of view. In addition, the real-time parameter adjustment and optimization mechanism further improves the adaptability of the system, providing drivers with a more comfortable and safe driving environment.

[0036] Principle of the embodiment: Figure 2 As shown, the optical machine 1, as an image generator, can transmit the image carrying navigation information to the optical waveguide 2 through total reflection. The coupling region of the optical waveguide 2 has a grating structure, which can deflect the light, so that the light is transmitted through total reflection in the optical waveguide 2, and the image is coupled out at a certain spatial angle through the grating structure in the coupling region, reaching the free-form mirror 3, to the car windshield 4, and then reflected to the human eye position of the human head model 5 through the car windshield 4, so that the driver can see the navigation virtual image presented by the light on the road ahead, thereby realizing the navigation function. Among them, the free-form lens 3 can be flipped according to the eye box adjustment range.

[0037] Embodiment 2 In order to solve the problem of complex grating structure design and difficult processing in the existing HUD system, this embodiment further optimizes the grating structure design of the optical waveguide coupling region. Specifically, this embodiment ensures the efficient transmission of the light beam in the optical waveguide and the deflection accuracy of the grating through calculation.

[0038] In this embodiment, the light beam generated by the optical machine is initially shaped by the beam shaping element and then enters the coupling region having a grating structure. The design of the grating structure follows the following relationship: ; Among them, θ0 is the deflection angle of the incident light of the grating, θ1 is the deflection angle of the outgoing light of the grating, is the incident light tilt angle of the grating, is the tilt angle of the grating output light, m ​​is the diffraction order, λ is the wavelength of light, d is the grating constant, and n is the refractive index of the incident medium. Through this equation, the parameters of the grating can be accurately calculated to ensure that the deflection angle and tilt angle of the light beam when entering the optical waveguide meet the design requirements.

[0039] Furthermore, the parameter selection of the grating structure needs to take into account the refractive index of the optical waveguide, the wavelength of the light beam, and the required deflection angle. For example, for a laser light source designed for a wavelength of 532nm, a grating constant d of 1.5μm, a refractive index n of 1.5, and a diffraction order m of 1 can be selected. This combination of parameters can ensure that the light beam is fully reflected and transmitted in the optical waveguide while reducing light loss and aberration.

[0040] Furthermore, the coupling region of the optical waveguide can use a surface relief grating or a volume holographic grating. The specific grating type selection can be optimized according to different application scenarios and optical performance requirements. The surface relief grating manufacturing process is relatively mature and suitable for mass production; the volume holographic grating has higher diffraction efficiency and better optical performance, and is suitable for high-end models or special applications.

[0041] Furthermore, the optimization design of the grating structure also includes fine adjustment of the grating period and grating depth. Through numerical simulation and experimental verification, the most suitable grating parameters can be determined to achieve the best beam deflection effect and image quality. The optimization of the grating structure not only improves the coupling efficiency of the light beam, but also reduces the size of the optical waveguide, making it more compact and miniaturized. It can be understood that the optimization of this embodiment is not only applicable to the HUD system of the present invention, but can also be extended to other optical applications based on optical waveguides.

[0042] Through the optimization of the grating structure in this embodiment, the efficiency and accuracy of the optical waveguide HUD system in the process of beam coupling and transmission are improved, and the problem of difficult processing of the grating structure in the prior art is solved. Through accurate grating equation calculation and parameter optimization, not only the optical performance of the system is improved, but also the manufacturing cost is reduced, which is conducive to large-scale market promotion and application.

[0043] Embodiment 3 In order to solve the problem that the grating structure type is single and the aberration correction effect is poor in the existing HUD system, this embodiment optimizes the grating structure type of the optical waveguide coupling region. This embodiment adopts a surface relief grating or a volume holographic grating, and selects a suitable one-dimensional, two-dimensional or super grating structure according to actual application requirements.

[0044] In this embodiment, the light beam generated by the optical machine enters the grating structure of the coupling region after being initially shaped by the beam shaping element. The grating structure can be a surface relief grating or a volume holographic grating. Furthermore, the grating structure can be a one-dimensional grating, a two-dimensional grating or a super grating to meet different beam expansion and deflection requirements.

[0045] Furthermore, the one-dimensional grating structure mainly expands the light beam laterally, while the two-dimensional grating structure can achieve both lateral and longitudinal expansion. This design ensures that the light beam has a suitable divergence angle when entering the optical waveguide, thereby achieving efficient total reflection transmission in the optical waveguide. The supergrating structure combines the advantages of one-dimensional and two-dimensional gratings, and can achieve precise beam control and aberration correction in more complex optical systems. It should be understood that different types of grating structures are selected to meet the specific requirements of beam expansion and deflection in different application scenarios, thereby improving the applicability of the system.

[0046] Furthermore, the coupling-in region and the coupling-out region of the optical waveguide can both use the same or different grating structures. By using different types of gratings in the coupling-in region and the coupling-out region, the coupling efficiency and transmission performance of the light beam can be further optimized. For example, a one-dimensional grating is used in the coupling-in region for lateral beam expansion, and a two-dimensional grating is used in the coupling-out region for longitudinal beam expansion. This combination can effectively improve the uniformity and image quality of the light beam. It can be understood that the design of this multi-level grating structure not only improves the optical performance of the system, but also increases the complexity of the system. However, through reasonable process and material selection, the cost can be effectively controlled.

[0047] This embodiment improves the efficiency and accuracy of the optical waveguide HUD system in the process of beam expansion and deflection by optimizing the type and design of the grating structure, and solves the problems of the single grating structure type and poor aberration correction effect in the prior art. Through this embodiment, higher optical image quality and smaller device volume can be achieved, providing users with a clearer and more comfortable visual experience.

[0048] Embodiment 4 In order to solve the problem of single selection of optical waveguide substrate material and low optical efficiency in existing HUD systems, this embodiment further optimizes the substrate material and thickness parameters of the optical waveguide. Specifically, this embodiment ensures efficient transmission of light in the waveguide and realization of a large field of view by adjusting the refractive index and thickness of the optical waveguide substrate.

[0049] In this embodiment, the light beam generated by the optical machine enters the optical waveguide after preliminary shaping by the beam shaping element. The substrate material of the optical waveguide can be glass, resin or organic polymer crystal, and the specific selection depends on the required optical performance and manufacturing cost. Glass material has a high refractive index and good optical transparency, and is suitable for high-precision optical systems; resin material has a low manufacturing cost and high flexibility, and is suitable for large-scale production; organic polymer crystals have the optical properties of glass material while having a higher lightweight advantage. Furthermore, the refractive index of the optical waveguide substrate ranges from 1.4 to 2.8, and the specific numerical selection depends on the design parameters of the optical waveguide and the transmission requirements of the light beam.

[0050] Furthermore, the thickness of the optical waveguide substrate ranges from 0.5 mm to 5 mm, and the specific numerical selection needs to take into account the transmission efficiency of the optical waveguide and the miniaturization requirements of the device. For example, for an optical waveguide substrate with a thickness of 1 mm, the transmission angle of the light beam can be optimized by adjusting the refractive index of the substrate so that it is fully reflected and transmitted in the waveguide. It should be understood that the thickness and refractive index selection of the optical waveguide substrate have an important influence on the optical performance of the system, so detailed numerical simulation and experimental verification are required during the design.

[0051] Furthermore, both the coupling-in area and the coupling-out area of ​​the optical waveguide adopt a diffraction grating structure to ensure the deflection angle and efficiency of the light beam when entering and leaving the optical waveguide. By optimizing the substrate material and thickness, the transmission efficiency and image quality of the light beam can be significantly improved, and the light loss and aberration can be reduced.

[0052] This embodiment improves the efficiency and image quality of the optical waveguide HUD system during the light beam transmission process by optimizing the material and thickness parameters of the optical waveguide substrate, and solves the problems of single substrate material selection and low optical efficiency in the prior art. It can achieve a smaller device volume and higher optical performance, providing users with a clearer and more reliable HUD display effect.

[0053] Embodiment 5 In order to solve the problem of complex calculation and insufficient precision of the flip angle of the free-form surface mirror in the existing HUD system, this embodiment further optimizes the calculation method of the flip angle of the free-form surface mirror. Specifically, this embodiment introduces an accurate calculation formula to ensure that the free-form surface mirror can be accurately flipped according to the driver's eye position, thereby expanding the observation range of the eye box.

[0054] In this embodiment, the light beam generated by the optical machine is initially shaped by the beam shaping element and then enters the optical waveguide. The light beam coupled out of the optical waveguide is subjected to field expansion and aberration correction by the free-form mirror. The flip angle of the free-form mirror is calculated by the following formula: ; Among them, θflip is the flip angle of the free-form mirror, h eye is the height of the driver's eyes, h pivot is the rotation axis height of the free-form mirror, d mirror is the distance between the free-form mirror and the windshield. Through this formula, the flip angle of the free-form mirror can be accurately calculated to ensure that it can provide clear HUD information under different driver eye positions.

[0055] Furthermore, the rotation axis height h of the free-form mirror pivot The design parameters of the optical waveguide can be adjusted to ensure that the light beam can achieve the best deflection effect when passing through the free-form mirror. The distance d between the free-form mirror and the windshield mirror It also needs to be optimized according to the windshield position of the specific vehicle model to ensure that the light beam can be accurately reflected to the driver's eye position. It should be understood that the selection of these parameters directly affects the flipping accuracy of the free-form mirror and the display effect of the HUD.

[0056] Furthermore, the design of the free-form mirror adopts advanced free-form mirror processing technology, such as CNC grinding or high-precision injection molding, to ensure the surface accuracy and optical performance of the lens. By adjusting the flip angle of the free-form mirror in real time, it can adapt to the eye position and sitting posture of different drivers and improve the user experience. It can be understood that this design not only improves the eye box range, but also reduces the visual fatigue caused by the driver's frequent adjustment of the head or body posture, and improves the driving comfort and safety.

[0057] This embodiment significantly improves the display effect of the optical waveguide HUD system under different driver eye positions by optimizing the calculation method of the flip angle of the free-form surface mirror, and solves the problem of complex calculation and insufficient precision of the flip angle of the free-form surface mirror in the prior art. A larger eye box range can be achieved while ensuring the stability of the system.

[0058] Embodiment 6 In order to solve the problem that the flip angle adjustment of the free-form surface mirror in the existing HUD system relies on manual operation and is inflexible, this embodiment further optimizes the flip angle adjustment mechanism of the free-form surface mirror. Specifically, this embodiment automatically adjusts the flip angle of the free-form surface mirror by real-time detection of the driver's body posture and eye position to ensure that drivers of different heights and body shapes can clearly see the HUD information.

[0059] In this embodiment, the light beam generated by the optical machine enters the optical waveguide after being initially shaped by the beam shaping element. The light beam coupled out of the optical waveguide is subjected to field expansion and aberration correction by the free-form mirror. The flip angle of the free-form mirror is adjusted in real time according to the driver's body posture and eye position. Specifically, the system includes a driver position sensor, which can detect the driver's eye height and sitting posture in real time and transmit this information to the control circuit. The control circuit calculates the flip angle of the free-form mirror using the formula of the aforementioned embodiment based on the data input by the sensor.

[0060] Furthermore, the driver position sensor can be an optical-based sensor or an infrared-based sensor, and the specific choice depends on the required detection accuracy and cost. The sensor is usually installed in front of the driver in the car, such as above the steering wheel or the dashboard area, and can accurately detect the driver's eye position and sitting posture changes. It should be understood that the choice of sensor has a significant impact on the real-time detection accuracy and response speed of the system, so detailed testing and verification are required during the design.

[0061] Furthermore, the control circuit can not only adjust the flip angle of the free-form mirror according to the data input by the sensor, but also dynamically adjust the light source parameters according to the ambient light intensity and the complexity of the displayed content. For example, during the day or in a strong light environment, the control circuit can appropriately increase the brightness of the light source to ensure the clarity of the displayed information; at night or in a low light environment, the control circuit can appropriately reduce the brightness of the light source to reduce light pollution and energy consumption. It can be understood that this multi-parameter dynamic adjustment mechanism further improves the adaptability of the system.

[0062] This embodiment improves the display effect of the optical waveguide HUD system under different driver eye positions by real-time detection and adjustment of the flip angle of the free-form mirror, solving the problems of manual adjustment and inflexibility in the prior art. Through the design of this embodiment, a larger eye box range can be achieved, improving the user experience while ensuring the automatic adjustment function of the system.

[0063] Embodiment 7 In order to solve the problem that the adjustment of beam brightness and color balance in the existing HUD system relies on manual operation and has poor adaptability, this embodiment further optimizes the adjustment mechanism of the control circuit for beam brightness and color balance. Specifically, this embodiment automatically adjusts the brightness and color balance of the beam by real-time detection of ambient light conditions to ensure that the visual effect of the image can be optimized in different environments.

[0064] In this embodiment, the light beam generated by the optical machine is initially shaped by the beam shaping element and then enters the optical waveguide. The light beam coupled out of the optical waveguide is subjected to field expansion and aberration correction by a free-form mirror. The control circuit is capable of detecting ambient light conditions in real time and dynamically adjusting the brightness and color balance of the light beam according to these conditions. Specifically, the system includes an ambient light sensor that can detect the light intensity inside and outside the vehicle in real time and pass this information to the control circuit. The control circuit uses the following mechanism to adjust the brightness and color balance of the light source based on the data input by the sensor: Specifically, the ambient light sensor can be a photodiode-based sensor or a CMOS image sensor-based sensor, and the specific choice depends on the required detection accuracy and cost. The sensor is usually installed in front of the driver in the car, such as the edge of the windshield or the dashboard area, and can accurately detect changes in ambient light. It should be understood that the choice of sensor affects the real-time detection accuracy and response speed of the system, so detailed testing and verification are required during the design.

[0065] Furthermore, the control circuit includes a brightness adjustment module and a color balance adjustment module. The brightness adjustment module can adjust the brightness of the light source in real time according to the input data of the ambient light sensor. For example, during the day or in a strong light environment, the brightness adjustment module can appropriately increase the brightness of the light source to ensure the clarity of the displayed information; at night or in a low light environment, the brightness adjustment module can appropriately reduce the brightness of the light source to reduce light pollution and energy consumption. The color balance adjustment module can adjust the color temperature, chromaticity and color saturation of the light source in real time according to the complexity of the displayed content and the needs of the user to ensure the visual effect of the image in different environments.

[0066] Furthermore, the control circuit can also be adjusted according to the user's input instructions. For example, the user can adjust the display mode of the HUD through the touch screen or voice command, such as switching to day mode or night mode. The control circuit quickly adjusts the brightness and color balance of the light source according to the user's input instructions to provide users with personalized display effects.

[0067] Through the optimized design of the control circuit in this embodiment, the display effect of the optical waveguide HUD system under different environmental conditions can be significantly improved, solving the problems of manual adjustment and poor adaptability in the prior art. Through this embodiment, a more intelligent and automated brightness and color balance adjustment function can be achieved.

[0068] Embodiment 8 In order to improve the volume and cost problems faced by the existing HUD optical aberration correction system when achieving a large field of view angle and a large eye box range, this embodiment proposes a HUD optical aberration correction system for implementing a HUD optical aberration correction method.

[0069] Specifically, the optomechanical system uses a high-brightness LED light source, which has the characteristics of high photoelectric conversion efficiency and good color rendering, and can provide clear, bright and colorful images. In order to meet the HUD system's demand for high-resolution images, the optomechanical system also integrates advanced micro-display technology, such as TFT-LCD displays with high refresh rates and high contrast. The light beam generated by the light source is initially shaped and collimated by the beam shaping element to have a suitable divergence angle and spot size, which is convenient for subsequent optical waveguide coupling.

[0070] Furthermore, the optical waveguide element adopts a multi-layer refractive-diffractive hybrid two-dimensional optical waveguide design, which includes an in-coupling region and an out-coupling region. The in-coupling region has a grating structure, which can efficiently deflect the light beam so that it can be transmitted by total reflection in the optical waveguide. The design of the grating structure follows the grating equation to ensure that the propagation angle of the light in the waveguide meets the total reflection condition. The waveguide substrate material is a high-refractive-index organic polymer crystal with a thickness between 0.5 mm and 5 mm and a refractive index between 1.4 and 2.8. The waveguide bending and branching structure can achieve effective steering and distribution of the light beam, thereby reducing the volume of the system and improving optical efficiency.

[0071] Furthermore, the aberration correction element includes a free-form mirror, which has a moderate area and a mature processing technology, reducing the production cost. The free-form mirror is located in the outcoupling area of ​​the optical waveguide, and is used to expand the field of view and correct the aberration of the light beam coupled out of the optical waveguide. It should be understood that the free-form mirror can not only correct common types of aberrations, such as binocular parallax, distortion and MTF, but also flip the lens angle around the rotation axis according to the eye box adjustment range to ensure that the driver can obtain a clear image in different head positions. The aberration correction element also includes a binocular parallax correction module, a distortion correction module and an MTF optimization module, which work together to ensure the quality of the final displayed image.

[0072] Furthermore, the windshield acts as a reflective surface to reflect the corrected light beam to form a navigation virtual image. The control circuit connects and controls the optical waveguide element, the aberration correction element, the light source system and the image generation unit to ensure the normal operation of the system and the coordination between the various parts. The control circuit can adjust the aberration correction parameters, light source parameters and image display parameters in real time according to the environmental information detected by the sensor, the user's input instructions and the internal state of the system to adapt to different lighting conditions, display content and user perspectives. It should be understood that the design of the control circuit takes into account the stability and reliability of the system under different conditions, ensuring that the HUD system can provide consistent high-quality images.

[0073] The benefit of this embodiment is that by optimizing the design of the optical-mechanical system, optical waveguide components and aberration correction components, the volume and cost are reduced while improving image quality and driving safety. In addition, the adjustable characteristics of the free-form mirror enable the system to adapt to different driver head positions, enhancing the user experience.

[0074] Embodiment 9 In order to improve the display effect of the HUD optical aberration correction device, especially to realize naked-eye 3D display, this embodiment proposes a HUD optical aberration correction device. The correction device integrates a multilayer optical waveguide structure and optical components on the basis of traditional optical waveguide elements to support naked-eye 3D display. The multilayer optical waveguide structure can accommodate more optical functional units, such as polarizer holographic gratings for beam stratification and geometric array waveguides for beam steering. The integration of these structures not only improves the optical efficiency, but also enables the system to generate 3D images with a sense of depth.

[0075] Furthermore, each layer of the optical waveguide has a specific function, such as the first layer is used for preliminary shaping and collimation of the light beam, the second layer is used for stratification and spatial distribution of the light beam, and the third layer is used for final beam expansion and field of view enhancement. It should be understood that the collaborative work of these layer structures can achieve efficient 3D image generation and transmission, ensuring that the final displayed image has high resolution and clarity. In addition, the multi-layer optical waveguide structure can also reduce the loss of the light beam during transmission and improve the overall optical efficiency of the system.

[0076] Furthermore, the aberration correction element is further optimized in this embodiment, including a free-form mirror and other additional optical elements. The free-form mirror is used to expand the field of view and correct the aberration of the light beam coupled out of the optical waveguide to ensure the image quality at different viewing angles. It can be understood that the design of the free-form mirror takes into account the special needs of 3D images, such as different field of view angles and depth of focus. In addition, a special 3D image optimization module is added to adjust the depth, contrast and color balance of the image to ensure that the driver can get a realistic 3D visual experience.

[0077] Furthermore, the control circuit in this embodiment integrates more sensors and algorithms, which can detect changes in the driving environment and user's perspective in real time, and dynamically adjust the aberration correction parameters, light source parameters and image display parameters. For example, the control circuit can adjust the angle of the free-form mirror in real time according to the slight movement of the driver's head to ensure that the 3D image is always within the driver's optimal viewing angle. In addition, the control circuit can also automatically adjust the brightness and color of the light source according to the speed of the vehicle and the ambient light conditions, so that the 3D image can remain clear and comfortable under different conditions.

[0078] The benefit of this embodiment is that through the multi-layer optical waveguide structure and the optimized aberration correction element, naked-eye 3D display is achieved, and the display effect of the HUD system is improved. The intelligent design of the control circuit enables the system to adjust parameters in real time according to different driving environments and user needs, ensuring that high-quality 3D images are always provided.

[0079] Embodiment 10 In order to integrate the HUD optical aberration correction device into the vehicle, this embodiment further refines the design of the windshield and the control circuit. As the display surface of the HUD system, the vehicle's windshield needs to have high optical reflectivity and low scattering properties to ensure the clarity and brightness of the navigation virtual image. The material of the windshield is usually a multi-layer composite glass that is resistant to ultraviolet and infrared rays, and its surface is treated to reduce interference from ambient light. The size and shape of the windshield are designed to take into account the interior space of the vehicle and the driver's field of view, ensuring that the navigation virtual image can be presented at an appropriate distance and angle.

[0080] Furthermore, the control circuit integrates more environmental perception modules in this embodiment to detect the environmental conditions inside and outside the vehicle in real time, such as light intensity, temperature, humidity and driving speed. The data of these sensors are used to dynamically adjust the aberration correction parameters, light source parameters and image display parameters. For example, the control circuit can adjust the brightness of the light source according to the external light intensity to ensure that the navigation virtual image can maintain appropriate contrast and clarity in both bright daytime and dim night. In addition, the control circuit can also adjust the display position and content of the navigation information in real time according to the driving speed and direction, ensuring that the driver can quickly and accurately obtain important information in different driving scenarios.

[0081] Furthermore, the control circuit also integrates a user input module for receiving the driver's instructions, such as operating through buttons on the steering wheel or a touch screen. The user input module can be used to adjust the display mode of the image, such as switching between normal mode and 3D mode. The control circuit will adjust the aberration correction element and light source parameters in real time according to the user's instructions to provide the best display effect. In addition, a user-defined setting function is added, such as adjusting the font size, color and position of the navigation information to meet the personalized needs of different drivers.

[0082] Furthermore, the algorithm design of the control circuit has been optimized, especially for the generation and transmission of 3D images, to reduce computing delays and improve the image response speed. The algorithm design takes into account the characteristics of optical waveguide components to ensure efficient transmission of light beams between different layers. In addition, the control circuit also integrates fault detection and automatic recovery functions, which can promptly alarm and restore to normal state when the system is abnormal, improving the reliability of the system.

[0083] The benefit of this embodiment is that by optimizing the design of the front windshield and the control circuit, the HUD optical aberration correction device is seamlessly integrated into the vehicle. The intelligent control circuit and user-defined setting function enable the system to provide the best display effect according to different driving environments and user needs, thereby improving driving safety and comfort.

[0084] The above embodiments further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the present invention should be included in the scope of protection of the present invention.

Claims

1. A HUD optical aberration correction method, characterized in that: The steps of the calibration method include: Generate a light beam through an LED light source or a laser light source, and adjust the brightness and color parameters of the LED light source or the laser light source through a control circuit to adapt to different display requirements and environmental conditions; The light beam is initially shaped and collimated by a beam shaping element until a suitable divergence angle and spot size are met to meet the requirements of the coupling element; The light beam enters the optical waveguide through an incoupling region having a grating structure, and the grating structure deflects the light beam so that the light beam is transmitted by total reflection in the optical waveguide until it reaches an outcoupling region; The coupled light beam coupled out from the optical waveguide passes through a free-form mirror to form a correction light beam for expanding the field of view and correcting aberrations. The free-form mirror flips according to the eye box adjustment range to enhance the imaging effect and ensure that different eye positions of drivers can be imaged clearly. The corrected light beam is reflected through the windshield into the driver's field of vision to form a navigation virtual image, so as to present navigation information on the road ahead to the driver; The control circuit detects environmental information, user input instructions and the internal state of the system in real time, and dynamically adjusts aberration correction parameters, light source parameters and image display parameters to optimize the display effect.

2. The HUD optical aberration correction method according to claim 1, characterized in that: The design of the grating structure in the coupling region of the optical waveguide is as follows: ； Among them, θ0 is the deflection angle of the incident light of the grating, θ1 is the deflection angle of the outgoing light of the grating, is the incident light tilt angle of the grating, is the tilt angle of the grating output light, m ​​is the diffraction order, λ is the wavelength of light, d is the grating constant, and n is the refractive index of the incident medium.

3. The HUD optical aberration correction method according to claim 1, characterized in that: The grating structure is a surface relief grating or a volume holographic grating, and the grating structure includes a one-dimensional grating, a two-dimensional grating or a super grating.

4. The HUD optical aberration correction method according to claim 1, wherein: The light beam after passing through the diffraction waveguide satisfies that the propagation angle of the light in the waveguide is greater than the Brewster angle: ； Where α is the propagation angle of the light in the waveguide, n b is the refractive index of the optical waveguide substrate, 1.4≤n b ≤2.8; The optical waveguide substrate is made of glass, resin or organic polymer crystal, and the thickness of the optical waveguide substrate is d b , 0.5mm≤d b ≤5mm.

5. The HUD optical aberration correction method according to claim 1, wherein: The flip angle of the free-form surface mirror is calculated by the following formula: ； Among them, θ flip is the flip angle of the free-form mirror, h eye is the height of the driver's eyes, h pivot is the rotation axis height of the free-form mirror, d mirror is the distance between the free-form mirror and the windshield.

6. The HUD optical aberration correction method according to claim 1, wherein: The flip angle of the free-form mirror is adjusted in real time according to the driver's body posture and eye position to ensure that drivers of different heights and body shapes can clearly see the HUD information.

7. The HUD optical aberration correction method according to claim 1, wherein: During the formation of the navigation virtual image, the brightness and color balance of the light beam are adjusted in real time by the control circuit to adapt to different ambient lighting conditions and ensure the visual effect of the image.

8. A HUD optical aberration correction system, used to implement the HUD optical aberration correction method according to any one of claims 1 to 7, characterized in that: The correction system comprises: An optical machine, which includes a high-brightness LED or laser light source, for generating a light beam and adjusting the brightness and color parameters of the light beam, for providing a clear, bright and colorful image; An optical waveguide, comprising an incoupling region and an outcoupling region, wherein the incoupling region has a grating structure and can deflect a light beam to perform total reflection transmission in the optical waveguide; An aberration correction element, comprising a free-form surface mirror, for expanding the field of view and correcting the aberration of the light beam coupled out from the optical waveguide, wherein the free-form surface mirror flips the lens angle around the rotation axis according to the eye box adjustment range to achieve clear imaging within a large eye box range; A windshield, used to reflect the corrected light beam to form a navigation virtual image; A control circuit, connected to and controlling the optical waveguide element, the aberration correction element, the light source system and the image generation unit, for controlling and operating the correction system; The aberration correction element further comprises: Binocular parallax correction module, used to optimize binocular parallax; A distortion correction module, used to correct the distortion in the optical system; The MTF optimization module is used to optimize the modulation transfer function of the correction system to improve the resolution and clarity of the image.

9. A HUD optical aberration correction device, characterized in that: The correction device includes the HUD optical aberration correction system as described in claim 8, and the correction device also includes a naked-eye 3D implementation system, which is used for naked-eye 3D display by integrating a multi-layer optical waveguide structure and optical components in the optical waveguide element.

10. A vehicle, characterized in that: The vehicle includes the HUD optical aberration correction device according to claim 9, and the vehicle further includes: The front windshield serves as a display surface of the correction device and is used to reflect the light beam to form a navigation virtual image; The control circuit is used to detect environmental information, user input instructions and the internal state of the system in real time, and dynamically adjust aberration correction parameters, light source parameters and image display parameters to optimize the display effect.

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