Vehicle-mounted projection display system, vehicle-mounted HUD system and vehicle

Abstract

The embodiment of the invention provides a vehicle-mounted projection display system, a vehicle-mounted HUD system and a vehicle. The vehicle-mounted projection display system comprises a projection lens and a depth-of-field expansion element, the projection lens comprises a first lens group, a diaphragm, a second lens group, an equivalent prism and a display chip which are arranged along the same optical axis. And the depth-of-field expansion element is arranged between the second lens group and the equivalent prism or between the equivalent prism and the display chip, and the depth-of-field expansion element can be used for forming virtual images with different depths of field within the projection distance of the projection lens.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of vehicle-mounted optical display technology. More specifically, the embodiments of the present application relate to a vehicle-mounted projection display system, a vehicle-mounted HUD system and a vehicle. Background Art

[0002] With the continuous development of the automobile industry, driving safety and comfort have become important considerations in automobile design. In order to improve safety and comfort during driving, head-up display systems (HUD) are gradually being widely used in automobile smart cockpits. The HUD system can display vehicle driving information, such as speed, navigation instructions, etc. within the driver's field of vision, thereby reducing interference with the driver's field of vision and improving driving safety.

[0003] However, current W-HUD (windshield head-up display) or AR-HUD (augmented reality head-up display) systems generally have the problem of fixed and single virtual image distance. Due to the fixed virtual image distance, current HUD systems are difficult to meet the information display requirements in different driving scenarios, limiting their potential in improving driving safety and comfort. Summary of the invention

[0004] The purpose of this application is to provide a new technical solution for a vehicle-mounted projection display system, a vehicle-mounted HUD system and a vehicle.

[0005] In a first aspect, the present application provides a vehicle-mounted projection display system. The vehicle-mounted projection display system includes a projection lens and a depth of field extension element;

[0006] The projection lens comprises a first lens group, an aperture, a second lens group, an equivalent prism and a display chip arranged along the same optical axis;

[0007] The depth of field extension element is arranged between the second lens group and the equivalent prism, or between the equivalent prism and the display chip. The depth of field extension element can be used to form virtual images with different depths of field within the projection distance of the projection lens.

[0008] Optionally, the depth of field extension element includes a light-transmitting flat plate element and a driving source, wherein the driving source is used to control the thickness change or position movement of the light-transmitting flat plate element, so that the position of the projection surface can be adjusted within the projection distance, so that a virtual image with different depths of field can be formed within the projection distance.

[0009] Optionally, the refractive index Nd of the light-transmitting flat plate element is: 1.5<Nd<1.9.

[0010] Optionally, the light-transmitting flat plate element is a liquid lens, a replaceable multi-thickness glass sheet group, or a pluggable glass compensation sheet.

[0011] Optionally, the light-transmitting flat plate element is a liquid lens;

[0012] The two opposite plane surfaces of the liquid lens are made of transparent rigid materials, and the peripheral side of the liquid lens is made of flexible material;

[0013] Under the control of the driving source, the thickness of the liquid lens can be continuously changed, thereby achieving continuous adjustment of the position of the projection surface within the projection distance.

[0014] Optionally, when the light-transmitting flat element is the liquid lens, the driving source is used to control the thickness of the liquid lens to continuously change between 0.5 mm and 0.8 mm through voltage or current, thereby forming a continuously changing virtual image with different depths of field within a projection distance of 120 mm to 140 mm.

[0015] Optionally, the light-transmitting flat plate element is a replaceable glass sheet set with multiple thicknesses;

[0016] The replaceable multi-thickness glass sheet set comprises a base and a first glass dome, a second glass dome and a third glass dome arranged side by side on the base, wherein the thickness of each glass dome is different and arranged in sequence;

[0017] Under the control of the driving source, the second glass dome can move relative to the first glass dome or the third glass dome to switch to three projection surfaces at different positions within the projection distance.

[0018] Optionally, when the light-transmitting flat plate element is a replaceable glass sheet group with multiple thicknesses, the driving source is used to control the second glass dome to swap positions with the first glass dome or the third glass dome through electromagnetic signals, thereby realizing a display virtual image on any one of the three projection surfaces within a projection distance of 120 mm to 140 mm;

[0019] The thicknesses T of the first glass dome, the second glass dome and the third glass dome satisfy 0.5 mm ≤ T ≤ 1.8 mm, and are different from each other.

[0020] Optionally, the light-transmitting flat plate element is a pluggable glass compensation sheet;

[0021] The pluggable glass compensation sheet can be inserted or removed in the optical path between the equivalent prism and the display chip under the drive of the drive source, so as to realize simultaneous or separate display of virtual images on two projection surfaces at different positions within the projection distance.

[0022] Optionally, the pluggable glass compensation sheet is a glass sheet, and its thickness D satisfies 0.3 mm ≤ D ≤ 1.5 mm;

[0023] The pluggable glass compensation sheet has at least three states relative to the display chip:

[0024] In the first state, the pluggable glass compensation sheet is completely outside the optical path between the equivalent prism and the display chip;

[0025] In the second state, the pluggable glass compensation sheet is partially inserted into the optical path between the equivalent prism and the display chip;

[0026] In the third state, the pluggable glass compensation sheet is completely inserted into the optical path between the equivalent prism and the display chip and its center is located on the optical axis;

[0027] The driving source mechanically controls the pluggable glass compensation sheet to switch between the above three states, thereby realizing the simultaneous or separate display of virtual images on two projection surfaces at a projection distance between 120 mm and 140 mm.

[0028] Optionally, the first lens group includes a first lens, a second lens and a third lens sequentially arranged along the optical axis;

[0029] The second lens group includes a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence along the optical axis;

[0030] The aperture is located between the third lens and the fourth lens, and the equivalent prism and the display chip are located on a side of the seventh lens away from the sixth lens.

[0031] Optionally, the fourth lens and the fifth lens are glued together to form a glued lens;

[0032] The first lens and the seventh lens are aspherical lenses.

[0033] In a second aspect, the present application provides a vehicle-mounted HUD system, the vehicle-mounted HUD system comprising:

[0034] The vehicle-mounted projection display system as described in the first aspect.

[0035] In a third aspect, the present application provides a vehicle, the vehicle comprising:

[0036] The vehicle-mounted HUD system as described in the second aspect.

[0037] The beneficial effects of this application are:

[0038] The embodiment of the present application provides a vehicle-mounted projection display system, which realizes multi-focal plane projection and depth of field extension functions within the projection distance by combining the depth of field extension element with the projection lens. This breaks through the limitations of the traditional vehicle-mounted HUD system with a fixed virtual image distance and a single projection surface, thereby enhancing the adaptability and practicality of the vehicle-mounted HUD system in different driving environments, providing the driver with more flexible and comprehensive visual information support, thereby effectively improving the safety and comfort during driving.

[0039] Other features and advantages of the present specification will become apparent from the following detailed description of exemplary embodiments of the present specification with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the specification and, together with the description, serve to explain the principles of the specification.

[0041] Figure 1 One of the optical structures and optical path diagrams of the vehicle-mounted projection display system according to an embodiment of the present application;

[0042] Figure 2 A schematic diagram of the thickness direction of the liquid lens of an embodiment of the present application;

[0043] Figure 3 for Figure 1 One of the MTF curves of the vehicle-mounted projection display system shown;

[0044] Figure 4 for Figure 1 The second MTF curve of the vehicle-mounted projection display system is shown;

[0045] Figure 5 for Figure 1 The third MTF curve of the vehicle-mounted projection display system is shown;

[0046] Figure 6 for Figure 1 The fourth MTF curve of the vehicle-mounted projection display system is shown;

[0047] Figure 7 for Figure 1 The fifth MTF curve of the vehicle-mounted projection display system is shown;

[0048] Figure 8 for Figure 1 The thickness variation and projection distance variation curve of the liquid lens shown;

[0049] Fig. 9 This is the second optical structure and optical path diagram of the vehicle-mounted projection display system of the embodiment of the present application;

[0050] Fig.10 This is a schematic structural diagram of a replaceable multi-thickness glass sheet set according to an embodiment of the present application;

[0051] Fig.11 for Figure 2 One of the MTF curves of the vehicle-mounted projection display system shown;

[0052] Fig.12 for Figure 2 The second MTF curve of the vehicle-mounted projection display system is shown;

[0053] Fig.13 for Figure 2 The third MTF curve of the vehicle-mounted projection display system is shown;

[0054] Fig.14 The third optical structure and optical path diagram of the vehicle-mounted projection display system according to an embodiment of the present application;

[0055] Fig.15 for Fig.14 Schematic diagram of three states of the pluggable glass compensation sheet shown in FIG.

[0056] Fig.16 for Fig.14 One of the MTF curves of the vehicle-mounted projection display system shown;

[0057] Fig.17 for Fig.14 The second MTF curve of the vehicle-mounted projection display system is shown;

[0058] Fig.18 for Fig.14 The third MTF curve of the vehicle-mounted projection display system is shown;

[0059] Fig.19 for Fig.14 The fourth MTF curve of the vehicle-mounted projection display system is shown.

[0060] Description of reference numerals:

[0061] 100. Projection lens;

[0062] 110, first lens group; 111, first lens; 112, second lens; 113, third lens;

[0063] 120, second lens group; 121, fourth lens; 122, fifth lens; 123, sixth lens; 124, seventh lens;

[0064] 130, aperture; 140, equivalent prism; 150, display chip; 160, protective glass;

[0065] 200. Depth of field extension element;

[0066] 210, liquid lens; 211, plane surface; 212, peripheral side; 213, filling liquid;

[0067] 220, replaceable multi-thickness glass sheet set; 221, first glass dome; 222, second glass dome; 223, third glass dome; 224, base;

[0068] 230. Pluggable glass compensation piece. DETAILED DESCRIPTION

[0069] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0070] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0071] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.

[0072] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0073] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0074] The following is a detailed description of the vehicle-mounted projection display system, the vehicle-mounted HUD system and the vehicle provided in the embodiments of the present application in conjunction with the accompanying drawings.

[0075] According to an embodiment of the present application, a vehicle-mounted projection display system is provided. Figure 1 , Fig. 9 and Fig.14 The vehicle-mounted projection display system includes a projection lens 100 and a depth of field extension element 200; the projection lens 100 includes a first lens group 110, an aperture 130, a second lens group 120, an equivalent prism 140 and a display chip 150 arranged along the same optical axis; the depth of field extension element 200 is arranged between the second lens group 120 and the equivalent prism 140, or between the equivalent prism 140 and the display chip 150, and the depth of field extension element 200 can be used to form virtual images with different depths of field within the projection distance of the projection lens 100.

[0076] The vehicle-mounted projection display system provided in the embodiment of the present application is shown in FIG. Figure 1 , Fig. 9 and Fig.14 The vehicle-mounted projection display system, by combining the projection lens 100 and the depth of field extension element 200, can form a virtual image with different depths of field within a set projection distance, thereby significantly improving the applicability and information display effect of the vehicle-mounted HUD (vehicle head-up display system) in different driving environments.

[0077] Traditional in-vehicle HUD systems mostly use a fixed and single virtual image distance, which limits the applicability of information in different driving environments. The in-vehicle projection display system provided in the embodiment of the present application, by introducing a depth of field extension element 200 in the projection lens 100, can form virtual images with different depths of field within the projection distance of the projection lens 100, thereby adapting to driving needs at different distances and improving the applicability of information.

[0078] The vehicle-mounted projection display system provided in the embodiment of the present application mainly includes two key components: a projection lens 100 and a depth of field extension element 200, which are described in detail below.

[0079] About Projection Lens 100:

[0080] The projection lens 100 is the core optical component of the entire vehicle-mounted projection display system. It includes a plurality of carefully designed optical elements arranged in an orderly manner along the same optical axis. These optical elements work together to shape, converge and transmit the light beam from the display chip 150, and finally form a clear image within a set projection distance.

[0081] The display chip 150 is, for example, a DMD (digital micromirror device).

[0082] The projection lens 100 includes two lens groups: a first lens group 110 and a second lens group 120 , and an aperture 130 is disposed between the first lens group 110 and the second lens group 120 .

[0083] The first lens group 110 is located at the front end of the projection lens 100 and is responsible for receiving the light beam from the display chip 150 and performing preliminary optical processing, such as correcting aberrations and controlling the divergence angle of the light beam.

[0084] The aperture 130 is located between the first lens group 110 and the second lens group 120 and is used to limit the diameter of the light beam and control the amount of light entering the subsequent optical system to optimize the imaging quality.

[0085] The second lens group 120 is located behind the aperture 130 and is used to further correct and optimize the light beam to ensure that the image reaches the best state on the projection surface.

[0086] The projection lens 100 further includes an equivalent prism 140 and a display chip 150 .

[0087] The equivalent prism 140 and the second lens group 120 are adjacent to each other and are spaced apart. The equivalent prism 140 is used to change the propagation direction of the light beam or to achieve other special optical effects, such as polarization conversion.

[0088] The display chip 150 (such as DMD) is used as the source of image generation, and controls the brightness of each pixel by flipping the micromirror array to form a final image.

[0089] Optionally, a protective glass 160 is disposed on a surface of the display chip 150 adjacent to the equivalent prism 140 .

[0090] The most direct function of the protective glass 160 is to protect the display chip 150 from direct damage by dust, water vapor, dirt or other impurities in the external environment. Since the display chip is a precision optical component, once it is contaminated or damaged, it will directly affect the quality of the projected image and the stability of the entire optical system. As a barrier, the protective glass 160 can effectively isolate external contaminants and extend the service life of the display chip 150. In addition, vibration and impact are inevitable in a vehicle environment. The protective glass 160 has high hardness and wear resistance, and can effectively prevent scratches or damage to the surface of the display chip 150 caused by vibration or accidental touch, thereby maintaining the clarity and integrity of the projected image.

[0091] About Depth of Field Extension Element 200:

[0092] The depth of field extension element 200 is placed between the second lens group 120 and the equivalent prism 140, or between the equivalent prism 140 and the display chip 150. This position is selected to introduce additional optical effects in the optical path, thereby achieving dynamic adjustment of the projection surface position and multiple depth of field display effects without changing the basic structure of the projection lens 100.

[0093] In the vehicle-mounted projection display system of the present application, the core function of the depth of field extension element 200 is to be able to form virtual images with different depths of field within the projection distance of the projection lens 100 .

[0094] It should be noted that the projection distance refers to Figure 1, the distance between the projection lens 100 and the projection surface. In the embodiment of the present application, the projection lens 100 is designed to be able to form a clear image within a certain projection distance range (such as 120mm to 140mm, including the two endpoints of 120mm and 140mm).

[0095] Depth of field refers to the depth range within which a clear image can be maintained on the projection surface. Through the function of the depth of field extension element 200, the vehicle-mounted projection display system of the present application can form virtual images with different depths of field within the projection distance, thereby improving the readability and applicability of information in different environments.

[0096] The vehicle-mounted projection display system provided by the embodiment of the present application can bring the following technical effects:

[0097] The setting of the depth of field extension element 200 enables the entire vehicle-mounted projection display system to dynamically adjust the position and depth of field of the virtual image according to changes in the driving environment, ensuring that the driver can clearly see the required information in different situations, thereby improving the information display effect and driving safety.

[0098] In some examples of the present application, the depth of field extension element 200 includes a light-transmitting flat element and a driving source, wherein the driving source is used to control the thickness change or position movement of the light-transmitting flat element, so that the position of the projection surface can be adjusted within the projection distance, so that a virtual image with a different depth of field can be formed within the projection distance.

[0099] In the example provided in the present application, a specific implementation method of the depth of field extension element 200 is described, that is, the position of the projection surface is controlled by a combination of a light-transmitting flat plate element and a driving source, thereby forming a virtual image with different depths of field within the projection distance of the projection lens 100.

[0100] The depth of field extension element 200 can dynamically adjust the position of the projection surface. Specifically:

[0101] By controlling the thickness change or position movement of the light-transmitting flat plate element through the driving source, the position of the projection surface can be flexibly adjusted. This dynamic adjustment capability enables the formed vehicle-mounted HUD system to adapt to different driving environments and needs, and improves the readability and applicability of information.

[0102] Since the position of the projection surface can be changed, virtual images with different depths of field can be formed within a certain projection distance. This multi-depth display effect helps drivers recognize information more accurately in complex environments, improving driving safety and comfort.

[0103] In the present application, by precisely controlling the thickness or position of the light-transmitting flat plate element, the MTF (modulation transfer function) performance of the system can be further optimized to ensure that the image remains clear at different depths of field.

[0104] Compared with other complex depth of field extension technologies, the solution structure in this example of the present application is relatively simple and easy to implement and maintain, which helps to reduce the complexity and cost of the system and improve the market competitiveness of the product.

[0105] This example of the present application further describes the composition and function of the depth of field extension element 200.

[0106] In some examples of the present application, the refractive index Nd of the light-transmitting flat plate element is: 1.5<Nd<1.9.

[0107] In the example of the present application, one of the core components of the depth of field extension element 200 is a specially designed light-transmitting flat plate element, the refractive index Nd of which is limited to between 1.5 and 1.9. The limitation of this refractive index range is closely related to the use of glass material for the light-transmitting flat plate element, and brings about significant technical effects. The following is a detailed analysis of this example and a description of the technical effects.

[0108] The refractive index of glass material is one of the key factors affecting the propagation characteristics of light inside it. By limiting the refractive index to the range of 1.5 to 1.9, it can be ensured that the light-transmitting flat plate element maintains excellent optical properties in different optical path configurations, such as low dispersion and high light transmittance, which is beneficial to the imaging quality of the projection display system.

[0109] The refractive index range designed in this example of the present application covers a variety of optical glass materials, allowing designers to select the most suitable material to manufacture light-transmitting flat plate elements as needed. This flexibility helps meet the performance requirements in different application scenarios.

[0110] In the vehicle-mounted projection display system, aberration is an important factor affecting the image quality. By precisely controlling the refractive index of the transparent flat plate element, the aberration caused by the mismatch of the material refractive index can be reduced, thereby improving the imaging clarity of the system.

[0111] The refractive index of the light-transmitting flat panel element is limited to the above reasonable range, which helps to reduce the loss and distortion of light during propagation, thereby improving the clarity of the projected image. This is especially important for application scenarios such as in-vehicle HUD that require high-precision display.

[0112] In some examples of this application, see Figure 1 , Fig. 9 and Fig.14The light-transmitting flat plate element is a liquid lens 210 , a replaceable multi-thickness glass sheet group 220 , or a pluggable glass compensation sheet 230 .

[0113] In the example of the present application, the light-transmitting flat plate element is designed as a liquid lens 210, a replaceable multi-thickness glass plate group 220 or a pluggable glass compensation plate 230. These three structures have their own characteristics and constitute the core part of the depth of field extension element 200.

[0114] See also Figure 1 When the light-transmitting flat plate element in the depth-of-field extension element 200 is a liquid lens 210, see Figure 2 By changing the thickness of the liquid lens 210 through the driving source, the projection surface position can be continuously changed within the range of 120mm to 140mm (including the two endpoints of 120mm and 140mm), while ensuring the clarity of the image. This capability enables the vehicle-mounted projection display system to adapt to different driving environments and vision requirements. In addition, the liquid lens has a fast adjustment speed and can quickly respond to changes in the user's vision or driving environment, providing a smoother and more natural visual experience.

[0115] See also Fig. 9 and Fig.10 When the light-transmitting flat plate element in the depth of field extension element 200 is a replaceable multi-thickness glass sheet group 220, the multi-thickness glass sheet group 220 is, for example, composed of multiple glass sheets of different thicknesses, each of which can be switched by an electromagnetic signal. The material and thickness of the glass sheet can be selected and adjusted as needed. This multi-thickness glass sheet group 220 has a discontinuous zoom capability, which can achieve a clear display of any three projection positions within the projection distance of the projection lens 100 within the range of 120mm to 140mm (including the two endpoints of 120mm and 140mm). This discontinuous zoom capability is suitable for application scenarios that require a specific viewing angle or distance.

[0116] See also Fig.10 The multi-thickness glass sheet group 220 shown in the figure can realize configurations of different focal lengths by replacing glass sheets of different thicknesses, thereby increasing the flexibility of the vehicle-mounted projection display system.

[0117] See also Fig.14 When the light-transmitting flat plate element in the depth-of-field extension element 200 is a pluggable glass compensation sheet 230, a pluggable design can be adopted, so that the user can insert or remove the glass compensation sheet in the optical path according to needs. Under this scheme, on the one hand, multiple projection surfaces can be displayed simultaneously: for example, within the range of 120mm to 140mm (including the two end points of 120mm and 140mm), any two projection positions can be selected for simultaneous clear display, see Fig.14 The middle projection plane 1 and the projection plane 2 are displayed simultaneously; on the other hand, single projection plane display can also be achieved: for example, any projection position within the range of 120 mm to 140 mm (including the two end values of 120 mm and 140 mm) can be selected for display, as can be seen in Fig.14 the projection plane a or the projection plane b in it is displayed separately. The user can switch the number and position of the projection planes through simple plug-and-play operations without complex debugging or calibration processes.

[0118] According to the three methods described in this example of the present application, whether it is continuous zoom, discontinuous zoom or the ability to display multiple projection planes simultaneously, it can greatly enhance the adaptability of the in-vehicle HUD system under different driving environments and line-of-sight requirements. By providing a more flexible and personalized visual experience, the comfort and safety of the driver are improved.

[0119] In some examples of the present application, as can be seen in Figure 1 , the light-transmitting flat plate element is a liquid lens; the two plane surfaces 211 opposite to the liquid lens 210, and these two plane surfaces 211 are made of transparent rigid materials, and the peripheral side 212 of the liquid lens 210 is made of flexible materials; under the control of the driving source, the thickness of the liquid lens 210 can change continuously, so as to realize the continuous adjustment of the projection plane position within the projection distance.

[0120] In this example of the present application, as can be seen in Figure 1 , the light-transmitting flat plate element is specifically embodied as a liquid lens 210, and the following is a detailed analysis and description of the technical effects of this example.

[0121] As can be seen in Figure 2 , the liquid lens 210 has two opposite plane surfaces 211, both of which are made of transparent rigid materials, ensuring the optical transparency and structural stability of the lens, and the curvature of the two surfaces of the liquid lens 210 will not change. Moreover, the peripheral side 212 of the liquid lens 210 is made of flexible materials, and this design allows the lens to deform flexibly when the thickness changes without causing rupture or deformation of the lens surface.

[0122] The liquid lens 210 of the present application has adjustable thickness. Under the control of a driving source such as voltage or current, the thickness of the liquid lens 210 can change continuously. This change is achieved by adjusting the distribution of the liquid inside the lens, etc., so as to realize the control of the optical path focal length.

[0123] The refractive index Nd of the liquid medium filled inside the liquid lens 210 satisfies a specific range, such as 1.50 < Nd < 1.9, which helps to maintain the excellent optical performance of the lens at different thicknesses.

[0124] When the light-transmitting flat plate element in the depth of field extension element 200 is a liquid lens 210, the projection surface position can be continuously adjusted within a specified projection distance (such as 120 mm to 140 mm) by controlling the continuous change of the thickness of the liquid lens 210. This capability enables the vehicle-mounted projection display system to dynamically adjust the position of the projected image according to the driver's vision requirements or changes in the driving environment, thereby improving driving comfort and safety.

[0125] The design of the liquid lens ensures that the curvature of the lens surface remains unchanged during the thickness change process, thus avoiding the aberration problem caused by the curvature change. This helps to maintain the clarity of the projected image and enhance the visual experience.

[0126] In addition, the thickness change of the liquid lens responds quickly and can quickly respond to changes in the user's line of sight or changes in the driving environment.

[0127] By continuously adjusting the position of the projection surface, the in-vehicle projection display system formed can be applied to the in-vehicle HUD system to provide a wider field of view, allowing the driver to obtain more driving information at the same time and improve the accuracy of driving decisions.

[0128] In summary, the design of using liquid lens 210 as a light-transmitting flat plate element in this application significantly improves the zoom capability and adaptability of the projection display system through its continuously adjustable thickness. This design not only solves the problem of fixed virtual image distance and single projection surface in traditional HUD systems, but also provides drivers with a more flexible and personalized visual experience through technological innovation.

[0129] In some examples of this application, see Figure 1 and Figure 2 When the light-transmitting flat element is the liquid lens 210, the driving source is used to control the thickness of the liquid lens 210 to continuously change between 0.5 mm and 0.8 mm through voltage or current, thereby forming a continuously changing virtual image with different depths of field within a projection distance of 120 mm to 140 mm.

[0130] In this example of the present application, the driving source is a voltage or a current. That is, the mechanism designed in this example is to control the thickness of the liquid lens 210 to change continuously within the range of 0.5 mm to 0.8 mm (including the two endpoints of 0.5 mm and 0.8 mm) by voltage or current. This control process directly affects the refraction and focusing of the projection light path, thereby generating a continuously changing virtual image with different depths of field within the projection distance of 120 mm to 140 mm.

[0131] The liquid lens design in this example of the present application can significantly expand the depth of field of the projection while maintaining image clarity through continuous adjustment of thickness, so that the displayed information can maintain ideal readability at different distances.

[0132] The thickness change of the liquid lens 210 is precisely controlled by voltage or current, making the depth of field adjustment process fast and accurate. This flexibility meets the information display requirements in different driving scenarios.

[0133] In this example of the present application, by using a liquid lens 210 as a light-transmitting flat plate element and combining voltage or current control to achieve continuous thickness changes, the problem of fixed virtual image distance and single projection surface in the traditional vehicle-mounted HUD system is solved. This technology not only enhances the applicability of the vehicle-mounted HUD system in complex driving environments, but also improves the safety and comfort during driving.

[0134] In some examples of this application, see Fig.10 The light-transmitting flat plate element is a replaceable multi-thickness glass sheet group 220; the replaceable multi-thickness glass sheet group 220 includes a base 224 and a first glass dome 221, a second glass dome 222 and a third glass dome 223 arranged side by side on the base 224, and the thickness of each glass dome is different and arranged in sequence;

[0135] Under the control of the driving source, the second glass dome 222 can move relative to the first glass dome 221 or the third glass dome 223 to switch to three projection surfaces at different positions within the projection distance.

[0136] In this example of the present application, the light-transmitting flat plate element is designed as a replaceable multi-thickness glass sheet set 220 of a special structure, see Fig.10 Under the control of the driving source, the second glass dome 222 located in the middle can selectively move relative to the first glass dome 221 or the third glass dome 223, thereby switching to three projection surfaces at different positions within the projection distance of the projection lens 100. This design enables the vehicle-mounted projection display system to maintain image clarity at discontinuous projection distances, meeting the requirements of multi-focal plane projection.

[0137] See also Fig.10 When the second glass dome 222 is located in the optical path, its center is located on the optical axis. Similarly, when the first glass dome 221 or the third glass dome 223 is switched to the optical path, the corresponding center is also located on the optical axis.

[0138] The multi-thickness glass panel design in this example of the present application allows the position of the projection surface to be quickly switched according to the specific driving environment or driver needs, thereby enhancing the environmental adaptability of the vehicle-mounted projection display system.

[0139] Integrating glass shrapnel of multiple thicknesses on a base 224 and achieving relative movement through electromagnetic or other driving mechanisms, this design is not only compact in structure, but also easy to implement and integrate into existing vehicle-mounted projection display systems. At the same time, the stability and durability of the glass material also ensure the long-term reliability of the system.

[0140] Through precise drive control, rapid and smooth switching between adjacent glass domes can be achieved, thereby ensuring the continuity and stability of the image when switching between different projection surfaces. This is of great significance for improving the efficiency of information acquisition and driving safety during driving.

[0141] It should be noted that, although three glass shrapnels of different thicknesses are shown in this example of the present application, in theory, the number of glass shrapnels can be increased or decreased as needed to accommodate a wider range of projection distance requirements.

[0142] In some examples of this application, see Fig. 9 and Fig.10 When the light-transmitting flat plate element is a replaceable multi-thickness glass sheet group 220, the driving source is used to control the second glass dome 222 to swap positions with the first glass dome 221 or the third glass dome 223 through an electromagnetic signal, so as to realize a display virtual image of any one of the three projection surfaces within a projection distance of 120 mm to 140 mm; wherein the thickness T of the first glass dome 221, the second glass dome 222 and the third glass dome 223 satisfies 0.5 mm ≤ T ≤ 1.8 mm, and are not equal to each other.

[0143] See also Fig. 9 and Fig.10 When the light-transmitting flat plate element adopts a replaceable multi-thickness glass sheet group 220, for example, the position of the second glass dome 222 and the first glass dome 221 or the third glass dome 223 can be swapped by electromagnetic signals, so that three different projection surfaces can be flexibly switched within a projection distance of 120mm to 140mm, and each projection surface can clearly display a virtual image. This design fully combines the principles of physical optics and mechanical control, and shows significant technical effects, which are specifically analyzed as follows:

[0144] Through the control of electromagnetic signals, the vehicle-mounted projection display system can quickly switch between three preset projection surfaces. Each projection surface corresponds to a different virtual image distance, meeting the diverse needs for information display locations in different driving scenarios.

[0145] Integrating multiple glass shrapnel on a base 224 and realizing position swapping through an electromagnetic mechanism is not only compact in structure, but also easy to integrate with the projection lens 100. At the same time, the stability and durability of the glass material also ensure the long-term reliable operation of the vehicle-mounted projection display system.

[0146] In some examples of this application, see Fig.14 and Fig.15 The light-transmitting flat plate element is a pluggable glass compensation plate 230; the pluggable glass compensation plate 230 can be inserted or pulled out in the optical path between the equivalent prism 140 and the display chip 150 under the drive of the driving source, so as to realize the simultaneous or separate display of virtual images on two projection surfaces at different positions within the projection distance.

[0147] In this example of the present application, the light-transmitting flat plate element in the depth of field extension element 200 is designed as a pluggable glass compensation sheet 230, which, under the drive of the driving source, can be flexibly inserted or pulled out in the optical path between the equivalent prism 140 and the display chip 150. This design allows the system to adjust the optical path according to the projection requirements, thereby realizing display at different projection positions.

[0148] By dynamically adjusting the position of the pluggable glass compensation sheet 230, the entire vehicle-mounted projection display system can quickly adapt to different projection requirements, support switching between two projection surfaces at different positions within a set projection distance, and enhance the flexibility of the vehicle-mounted projection display system.

[0149] Wherein, the pluggable glass compensation sheet 230 is a glass sheet.

[0150] In some examples of this application, see Fig.14 and Fig.15 The pluggable glass compensation sheet 230 is a glass sheet, and its thickness D satisfies 0.3 mm ≤ D ≤ 1.5 mm; the pluggable glass compensation sheet 230 has at least three states relative to the display chip 150:

[0151] In the first state, the pluggable glass compensation sheet 230 is completely outside the optical path between the equivalent prism 140 and the display chip 150;

[0152] In the second state, the pluggable glass compensation sheet 230 is partially inserted into the optical path between the equivalent prism 140 and the display chip 150;

[0153] In the third state, the pluggable glass compensation sheet 230 is completely inserted into the optical path between the equivalent prism 140 and the display chip 150 and its center is located on the optical axis;

[0154] The driving source mechanically controls the pluggable glass compensation sheet 230 to switch between the above three states, thereby realizing that the two projection surfaces with a projection distance between 120 mm and 140 mm display virtual images simultaneously or individually.

[0155] The example provided in this application further refines the design and application scenarios of the pluggable glass compensating sheet 230. The pluggable glass compensating sheet 230 is defined as a glass sheet with a thickness D of 0.3 mm to 1.5 mm, and three different insertion states are set to meet different projection requirements. The driving source can accurately control the switching of the compensating sheet between the three states by mechanical means. The driving source is, for example, a motor.

[0156] See also Fig.14 and Fig.15 Through the three different insertion states of the pluggable glass compensation sheet 230, the vehicle-mounted projection display system can support simultaneous or separate display of two different projection surfaces. This design increases the functionality and user experience of the vehicle-mounted projection display system.

[0157] The following describes the three states involved in this example of the present application respectively:

[0158] First state: see Fig.15 In the middle left figure, the pluggable glass compensator 230 is completely outside the optical path between the equivalent prism 140 and the display chip 150. In this state, the pluggable glass compensator 230 does not participate in the optical path transmission, and the optical path is directly transmitted from the equivalent prism 140 to the display chip 150. This is equivalent to not adding any additional optical elements, and the optical path remains the shortest and most direct. Since the glass compensator is not in the optical path, it will not have any additional optical impact on the projected image, ensuring the original clarity and color accuracy of the image.

[0159] Second state: see Fig.15 In the middle figure, the pluggable glass compensating sheet 230 is partially inserted into the optical path between the equivalent prism 140 and the display chip 150. In this state, the glass compensating sheet partially enters the optical path, and its thickness and position affect the light beam passing through. The glass compensating sheet can be inserted to different depths as needed to adjust the clarity or position of a specific projection surface.

[0160] It should be noted that, by partially inserting the glass compensation sheet, the vehicle-mounted projection display system can fine-tune the position or clarity of the projection surface as needed.

[0161] In the second state, the vehicle projection display system can support simultaneous display of two projection surfaces, one through a direct optical path and the other adjusted through a partially inserted glass compensation sheet, which increases the functionality and flexibility of the vehicle projection display system.

[0162] Third state: see Fig.15 In the middle right figure, the pluggable glass compensating sheet 230 is completely inserted into the optical path between the equivalent prism 140 and the display chip 150, and its center is located on the optical axis. In this state, the glass compensating sheet is completely inserted into the optical path, and its center is located on the optical axis. At this time, the glass compensating sheet has the greatest impact on the optical path, and its thickness and material need to be precisely controlled according to the specific optical design to ensure the clarity and position accuracy of the projected image.

[0163] The three-state design makes the pluggable glass compensation sheet adjustable in the vehicle projection display system. By mechanically controlling the switching of the glass compensation sheet between different states, the vehicle projection display system can achieve flexible adjustment of multiple projection surfaces and optimize the imaging quality while maintaining a compact structure. This design not only improves the functionality and user experience of the vehicle projection display system, but also ensures the stability and clarity of the image quality.

[0164] In summary, the depth of field extension element 200 provided by the present application, wherein the core component, the light-transmitting flat plate element, is designed with three different structures, namely the above-mentioned liquid lens 210, the replaceable multi-thickness glass sheet group 220 and the pluggable glass compensation sheet 230. Among them, the liquid lens 210 can control the distribution of the liquid inside the liquid lens through an electrical signal, thereby changing the focal length and optical focal length of the lens, and realizing continuous adjustment of the projection surface position. The replaceable multi-thickness glass sheet group 220 uses electromagnetic force to control the position switching of different glass shrapnel to realize discontinuous changes in the projection surface position. This method is suitable for scenes that need to fix several specific projection distances. The pluggable glass compensation sheet 230 changes the optical path length by inserting or pulling out glass compensation sheets of different thicknesses, thereby switching between two or more preset projection positions. This method is suitable for scenes that need to display multiple projection surfaces at the same time.

[0165] In some examples of this application, see Figure 1 , Fig. 9 and Fig.14The first lens group 110 includes a first lens 111, a second lens 112 and a third lens 113 arranged in sequence along the optical axis; the second lens group 120 includes a fourth lens 121, a fifth lens 122, a sixth lens 123 and a seventh lens 124 arranged in sequence along the optical axis; the aperture 130 is located between the third lens 113 and the fourth lens 121, and the equivalent prism 140 and the display chip 150 are located on a side of the seventh lens 124 away from the sixth lens 123.

[0166] The projection lens 100 includes two main lens groups: a first lens group 110 and a second lens group 120, as well as an aperture 130, an equivalent prism 140 and a display chip 150 (such as a DMD) located between the two lens groups. Specifically, the first lens group 110 includes a first lens 111, a second lens 112 and a third lens 113 arranged in sequence along the optical axis; the second lens group 120 includes a fourth lens 121, a fifth lens 122, a sixth lens 123 and a seventh lens 124. The aperture 130 is placed between the third lens 113 and the fourth lens 121 to control the flux and direction of the light. The equivalent prism 140 and the display chip 150 are located at the end of the entire lens system to ensure that the image can be accurately projected and displayed.

[0167] By grouping the lenses and precisely controlling the arrangement and parameters (such as the radius of curvature, thickness, refractive index, etc.) of each lens group, the imaging quality can be improved. In the present application, the first lens group 110 and the second lens group 120 work together to correct aberrations, thereby improving the clarity of the image.

[0168] The introduction of the aperture 130 not only limits the entry of stray light, but also helps to adjust the angle and distribution of light, so that the light can be more effectively focused on the display chip 150, reducing energy loss and improving light energy utilization.

[0169] In some examples of the present application, the fourth lens 121 and the fifth lens 122 are glued together to form a glued lens; the first lens 111 and the seventh lens 124 are aspherical lenses.

[0170] The design of cemented lenses can effectively correct aberrations in the system, especially chromatic aberration (including axial chromatic aberration and vertical chromatic aberration). By cementing lenses made of different materials together, the differences in the dispersion characteristics of light from different materials can be used to compensate each other, thereby reducing the impact of chromatic aberration on imaging quality.

[0171] In the present application, it is particularly pointed out that the first lens 111 and the seventh lens 124 are designed as aspherical lenses. Compared with traditional spherical lenses, aspherical lenses have a more complex surface shape and can better control the focusing characteristics of light at different positions, thereby improving imaging quality.

[0172] In the present application, the first lens 111 and the seventh lens 124 are designed as aspherical lenses, which can significantly reduce these aberrations and improve the clarity of the image; and the aspherical lenses can more accurately control the focus of the light, so that the clarity of the edge of the image is significantly improved. This helps to improve the resolution of the system and make the image more delicate and realistic.

[0173] The design of the vehicle-mounted projection display system of the present application is described in detail below through Examples 1 to 3.

[0174] Example 1

[0175] See also Figure 1 The vehicle-mounted projection display system includes a projection lens 100 and a depth of field extension element 200; the projection lens 100 includes a first lens group 110, an aperture 130, a second lens group 120, an equivalent prism 140 and a display chip 150 arranged along the same optical axis;

[0176] The first lens group 110 includes a first lens 111, a second lens 112, and a third lens 113 sequentially arranged along the optical axis; the second lens group 120 includes a fourth lens 121, a fifth lens 122, a sixth lens 123, and a seventh lens 124 sequentially arranged along the optical axis; the aperture 130 is located between the third lens 113 and the fourth lens 121, and the equivalent prism 140 and the display chip 150 are located on a side of the seventh lens 124 away from the sixth lens 123;

[0177] Wherein, the first lens 111 and the seventh lens 124 are aspherical lenses;

[0178] The depth of field extension element 200 is disposed between the second lens group 120 and the equivalent prism 140, or between the equivalent prism 140 and the display chip 150. The depth of field extension element 200 can be used to form virtual images with different depths of field within the projection distance of the projection lens 100.

[0179] The depth of field extension element 200 includes a liquid lens 210 and a driving source, wherein the driving source is used to control the thickness change of the liquid lens 210; Figure 2The two plane surfaces 211 of the liquid lens 210 are opposite to each other, and the two plane surfaces 211 are made of transparent rigid materials. The peripheral side 212 of the liquid lens 210 is made of flexible materials. The refractive index Nd of the liquid lens 210 is: 1.5<Nd<1.9; the driving source is used to control the thickness of the liquid lens 210 to continuously change between 0.5mm and 0.8mm through voltage or current, thereby forming a continuously changing virtual image with different depths of field within a projection distance of 120mm to 140mm.

[0180] Table 1 shows the optical parameters of the vehicle-mounted projection display system provided in Example 1.

[0181] Table 1

[0182]

[0183]

[0184] In the above Table 1:

[0185] S1 and S2 are two surfaces of the first lens 111 respectively, S1 is the surface of the first lens 111 away from the second lens 112, and S2 is the surface of the first lens 111 close to the second lens 112;

[0186] S3 and S4 are two surfaces of the second lens 112 respectively, S3 is the surface of the second lens 112 close to the first lens 111, and S4 is the surface of the second lens 112 close to the third lens 113;

[0187] S5 and S6 are two surfaces of the third lens 113 respectively, S5 is the surface of the third lens 113 close to the second lens 112, and S6 is the surface of the third lens 113 close to the aperture 130;

[0188] S7 is the surface where the aperture 120 is located;

[0189] S8 and S9 are two surfaces of the fourth lens 121, respectively. S8 is the surface of the fourth lens 121 close to the aperture 130, and S9 is the surface of the fourth lens 121 close to the fifth lens 122. Since the fourth lens 121 is glued to the fifth lens 122, one surface of the fifth lens 122 is glued to S9, and the other surface is S10.

[0190] S11 and S12 are two surfaces of the sixth lens 123 respectively, S11 is the surface of the sixth lens 123 close to the fifth lens 122, and S12 is the surface of the sixth lens 123 close to the seventh lens 124;

[0191] S13 and S14 are two surfaces of the seventh lens 124 , respectively. S13 is the surface of the seventh lens 124 close to the sixth lens 123 , and S14 is the surface of the seventh lens 124 close to the equivalent prism 140 .

[0192] S15 to S20 are different surfaces of the equivalent prism 140 .

[0193] In Embodiment 1, S1, S2, S13, and S14 are two aspherical surfaces of the first lens 1 and the second lens 7, and the surface shapes are described as follows:

[0194]

[0195] Among them, Z(h) is the vector height of the aspheric surface at a height of h along the optical axis and the distance from the vertex of the aspheric surface, where c = 1 / r, r represents the radius of curvature of the aspheric surface, k is the cone coefficient conic, and A, B, C, D, E, F, G, and H are the high-order coefficients of the aspheric surface.

[0196] Table 2 shows the aspheric parameters of the first lens 1 and the seventh lens 7 provided in Example 1.

[0197] Table 2

[0198]

[0199] The technical effect analysis of the continuous change of the projection distance between 120 mm and 140 mm in Example 1 is as follows:

[0200] See also Figures 3 to 7 MTF (Modulation Transfer Function) diagram in: MTF diagram is one of the important indicators for evaluating the imaging quality of optical systems. It can intuitively reflect the system's ability to transmit information of different spatial frequencies. The closer the MTF value is to 1, the more complete the system's information transmission of the spatial frequency is, and the better the imaging quality is.

[0201] Specifically, Figures 3 to 7 The MTF curves are shown at projection distances of 120mm, 125mm, 130mm, 135mm and 140mm respectively. These curves reflect the transmission of different spatial frequency information by the vehicle-mounted projection display system at different projection distances. Figures 3 to 7 It can be seen that as the projection distance increases from 120mm to 140mm, the shape and position of the MTF curve remain relatively stable, without obvious fluctuations or declines. This shows that the vehicle-mounted projection display system can maintain good imaging clarity at different projection distances.

[0202] Moreover, even in the high spatial frequency area, the MTF value remains at a high level, indicating that the system can effectively transmit high-frequency information in the image, ensuring the image's fineness and realism. The MTF curve has good performance from low frequency to high frequency, indicating that the system can fully and accurately transmit image information at different projection distances.

[0203] because Figures 3 to 7 The MTF curves in the figure can maintain a high level and be relatively stable at different projection distances, which verifies the technical effect that the projection surface can be continuously changed within the projection distance of 120mm to 140mm and the clarity meets the requirements in Example 1. This continuous change capability enables the projection display system to adapt to a wider range of usage scenarios and viewing needs.

[0204] See also Figure 8 , Figure 8 The graph shows the thickness variation of the liquid lens 210 when the projection distance varies from 120 mm to 140 mm. The horizontal axis represents the projection distance, ranging from 120 mm to 140 mm. The vertical axis represents the thickness of the liquid lens 210 in millimeters (mm).

[0205] from Figure 8 It can be seen that as the projection distance gradually increases from 120 mm to 140 mm, the thickness of the liquid lens 210 shows a gradual change trend. This change is close to linear. By controlling the change in the thickness of the liquid lens 210 through an electrical signal, the vehicle-mounted projection display system can quickly and accurately adjust the thickness of the liquid lens 210 when the projection distance changes to adapt to the new projection environment. This dynamic adjustment mechanism enables the vehicle-mounted projection display system to maintain a high imaging clarity when continuously changing the projection surface position within the projection distance range of 120 mm to 140 mm.

[0206] The correspondence between the thickness variation range of the liquid lens (0.5 mm to 1.8 mm in this embodiment 1) and the projection distance (120 mm to 140 mm) is carefully calculated and optimized to ensure the best imaging effect in the entire projection distance range.

[0207] The material selection (refractive index between 1.50 and 1.9) and structural design (transparent rigid film material on both sides and flexible foldable material on the edge) of the liquid lens 210 are both intended to support such thickness variation and maintain good optical performance.

[0208] Example 2

[0209] See also Fig. 9, which is different from the above-mentioned embodiment 1, in the optical structure of the vehicle-mounted projection display system, the core component of the depth of field extension element 200, the transparent flat plate element, adopts a replaceable multi-thickness glass sheet group 220;

[0210] The structure of the replaceable multi-thickness glass sheet set 220 can be seen in Fig.10 , which includes a base 224 and a first glass dome 221, a second glass dome 222 and a third glass dome 223 arranged side by side on the base 224, the thickness of each glass dome is different and they are arranged in sequence;

[0211] The driving source is used to control the second glass dome 222 to swap positions with the first glass dome 221 or the third glass dome 223 through electromagnetic signals, so as to realize a display virtual image on any one of the three projection surfaces within a projection distance of 120 mm to 140 mm;

[0212] The thicknesses T of the first glass dome 221 , the second glass dome 222 and the third glass dome 223 satisfy 0.5 mm≤T≤1.8 mm, and are different from each other.

[0213] Table 3 shows the optical parameters of the vehicle-mounted projection display system provided in Example 2.

[0214] Table 3

[0215]

[0216]

[0217] In the above Table 3:

[0218] S1 and S2 are two surfaces of the first lens 111 respectively, S1 is the surface of the first lens 111 away from the second lens 112, and S2 is the surface of the first lens 111 close to the second lens 112;

[0219] S3 and S4 are two surfaces of the second lens 112 respectively, S3 is the surface of the second lens 112 close to the first lens 111, and S4 is the surface of the second lens 112 close to the third lens 113;

[0220] S5 and S6 are two surfaces of the third lens 113 respectively, S5 is the surface of the third lens 113 close to the second lens 112, and S6 is the surface of the third lens 113 close to the aperture 130;

[0221] S7 is the surface where the aperture 120 is located;

[0222] S8 and S9 are two surfaces of the fourth lens 121, respectively. S8 is the surface of the fourth lens 121 close to the aperture 130, and S9 is the surface of the fourth lens 121 close to the fifth lens 122. Since the fourth lens 121 is glued to the fifth lens 122, one surface of the fifth lens 122 is glued to S9, and the other surface is S10.

[0223] S11 and S12 are two surfaces of the sixth lens 123 respectively, S11 is the surface of the sixth lens 123 close to the fifth lens 122, and S12 is the surface of the sixth lens 123 close to the seventh lens 124;

[0224] S13 and S14 are two surfaces of the seventh lens 124 , respectively. S13 is the surface of the seventh lens 124 close to the sixth lens 123 , and S14 is the surface of the seventh lens 124 close to the equivalent prism 140 .

[0225] S15 to S20 are different surfaces of the equivalent prism 140 .

[0226] In Embodiment 2, S1, S2, S13, and S14 are two aspherical surfaces of the first lens 1 and the second lens 7, and the surface shapes are described as follows:

[0227]

[0228] Among them, Z(h) is the vector height of the aspheric surface at a height of h along the optical axis and the distance from the vertex of the aspheric surface, where c = 1 / r, r represents the radius of curvature of the aspheric surface, k is the cone coefficient conic, and A, B, C, D, E, F, G, and H are the high-order coefficients of the aspheric surface.

[0229] Table 4 shows the aspheric parameters of the first lens 1 and the seventh lens 7 provided in Example 2.

[0230] Table 4

[0231]

[0232] Fig.11 , Fig.12 and Fig.13 The MTF (Modulation Transfer Function) diagrams correspond to projection distances of 120mm, 130mm, and 140mm respectively.

[0233] Fig.11 The MTF curve in the figure reflects the modulation capability of the vehicle projection display system for each spatial frequency at a projection distance of 120mm. A high MTF value indicates that the vehicle projection display system can better transmit image details, that is, the image clarity is high.

[0234] and Fig.11 compared to, Fig.12The MTF curve changes when the projection distance increases to 130mm. Due to the switching effect of glass domes of different thicknesses, the vehicle-mounted projection display system has been adjusted to the optical configuration that adapts to the new projection distance.

[0235] By comparison Fig.11 and Fig.12 The MTF curve can be used to evaluate the difference in imaging quality of the vehicle-mounted projection display system at different projection distances. It can be seen that the difference between the two is small, indicating that the vehicle-mounted projection display system can maintain good imaging consistency at different projection distances.

[0236] Fig.13 The MTF curve at the farthest projection distance of 140mm is shown. The MTF curve is still within an acceptable range at this distance, indicating that the vehicle-mounted projection display system has a wide imaging depth of field.

[0237] Combination Figures 11 to 13 It can be determined that the MTF curves at all projection distances meet the design requirements, indicating that the vehicle-mounted projection display system proposed in Example 2 can effectively support clear imaging on any three discontinuous projection surfaces between 120 mm and 140 mm.

[0238] Example 3

[0239] See also Fig.14 , which is different from the above-mentioned embodiment 1, in the optical structure of the vehicle-mounted projection display system, the core component of the depth of field extension element 200 is a pluggable glass compensation sheet 230; the pluggable glass compensation sheet 230 is a glass sheet, and its thickness D satisfies, 0.3mm≤D≤1.5mm; the pluggable glass compensation sheet 230 has at least three states relative to the display chip 150:

[0240] In the first state, the pluggable glass compensation sheet 230 is completely outside the optical path between the equivalent prism 140 and the display chip 150;

[0241] In the second state, the pluggable glass compensation sheet 230 is partially inserted into the optical path between the equivalent prism 140 and the display chip 150;

[0242] In the third state, the pluggable glass compensation sheet 230 is completely inserted into the optical path between the equivalent prism 140 and the display chip 150 and its center is located on the optical axis;

[0243] The driving source mechanically controls the pluggable glass compensation sheet 230 to switch between the above three states, thereby realizing that the two projection surfaces with a projection distance between 120 mm and 140 mm display virtual images simultaneously or individually.

[0244] Table 5 shows the optical parameters of the vehicle-mounted projection display system provided in Example 3.

[0245] Table 5

[0246]

[0247]

[0248] In the above Table 5:

[0249] S1 and S2 are two surfaces of the first lens 111 respectively, S1 is the surface of the first lens 111 away from the second lens 112, and S2 is the surface of the first lens 111 close to the second lens 112;

[0250] S3 and S4 are two surfaces of the second lens 112 respectively, S3 is the surface of the second lens 112 close to the first lens 111, and S4 is the surface of the second lens 112 close to the third lens 113;

[0251] S5 and S6 are two surfaces of the third lens 113 respectively, S5 is the surface of the third lens 113 close to the second lens 112, and S6 is the surface of the third lens 113 close to the aperture 130;

[0252] S7 is the surface where the aperture 120 is located;

[0253] S8 and S9 are two surfaces of the fourth lens 121, respectively. S8 is the surface of the fourth lens 121 close to the aperture 130, and S9 is the surface of the fourth lens 121 close to the fifth lens 122. Since the fourth lens 121 is glued to the fifth lens 122, one surface of the fifth lens 122 is glued to S9, and the other surface is S10.

[0254] S11 and S12 are two surfaces of the sixth lens 123 respectively, S11 is the surface of the sixth lens 123 close to the fifth lens 122, and S12 is the surface of the sixth lens 123 close to the seventh lens 124;

[0255] S13 and S14 are two surfaces of the seventh lens 124 , respectively. S13 is the surface of the seventh lens 124 close to the sixth lens 123 , and S14 is the surface of the seventh lens 124 close to the equivalent prism 140 .

[0256] S15 to S20 are different surfaces of the equivalent prism 140 .

[0257] In Embodiment 3, S1, S2, S13, and S14 are two aspherical surfaces of the first lens 1 and the second lens 7, and the surface shapes are described as follows:

[0258]

[0259] Among them, Z(h) is the vector height of the aspheric surface at a height of h along the optical axis and the distance from the vertex of the aspheric surface, where c = 1 / r, r represents the radius of curvature of the aspheric surface, k is the cone coefficient conic, and A, B, C, D, E, F, G, and H are the high-order coefficients of the aspheric surface.

[0260] Table 6 shows the aspheric parameters of the first lens 1 and the seventh lens 7 provided in Example 3.

[0261] Table 6

[0262]

[0263] Example 3 shows that by combining the pluggable glass compensation sheet 230 in the depth of field extension element 200, it is possible to achieve simultaneous display of any two projection surfaces or display one of them separately when the projection distance is between 120 mm and 140 mm to ensure clarity. Fig.16 , Fig.17 Respectively represent the MTF diagrams of projection surface a and projection surface b, and Fig.18 and Fig.19 The MTF diagrams of projection surface 1 and projection surface 2 are displayed simultaneously.

[0264] See also Fig.16 , a higher MTF value indicates that the image has higher clarity on this projection surface.

[0265] See also Fig.17 , Fig.17 The MTF curve is shown when the vehicle-mounted projection display system displays the projection surface b alone. Fig.16 and Fig.17 ,Comparing the two curves, it can be determined that: the imaging quality of the two projection surfaces is good when displayed separately.

[0266] Fig.18 and Fig.19 The MTF performance of two projection surfaces displayed simultaneously at different projection distances or configurations is demonstrated. It can be confirmed that the image quality of simultaneous display is also better.

[0267] According to another embodiment of the present application, a vehicle-mounted HUD system is provided, wherein the vehicle-mounted HUD system includes the vehicle-mounted projection display system as described above.

[0268] Among them, the vehicle-mounted projection display system is equivalent to the PGU part in the vehicle-mounted HUD system.

[0269] According to yet another embodiment of the present application, a vehicle is provided, wherein the vehicle includes the vehicle-mounted HUD system as described above.

[0270] The specific implementation of the vehicle-mounted HUD system and the vehicle in the embodiments of the present application can refer to the above-mentioned embodiments of the vehicle-mounted projection display system, and therefore at least have all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0271] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0272] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A vehicle-mounted projection display system, characterized in that: It comprises a projection lens (100) and a depth of field extension element (200); The projection lens (100) comprises a first lens group (110), an aperture (130), a second lens group (120), an equivalent prism (140) and a display chip (150) arranged along the same optical axis; The depth-of-field extension element (200) is arranged between the second lens group (120) and the equivalent prism (140), or between the equivalent prism (140) and the display chip (150), and the depth-of-field extension element (200) can be used to form virtual images with different depths of field within the projection distance of the projection lens (100).

2. The vehicle-mounted projection display system according to claim 1, characterized in that: The depth of field extension element (200) comprises a light-transmitting flat plate element and a driving source, wherein the driving source is used to control the thickness change or position movement of the light-transmitting flat plate element, thereby being able to adjust the position of the projection surface within the projection distance, so that virtual images with different depths of field can be formed within the projection distance.

3. The vehicle-mounted projection display system according to claim 2, characterized in that: The refractive index Nd of the light-transmitting flat plate element is: 1.5<Nd<1.

9.

4. The vehicle-mounted projection display system according to claim 3, characterized in that: The light-transmitting flat plate element is a liquid lens (210), a replaceable multi-thickness glass sheet group (220), or a pluggable glass compensation sheet (230).

5. The vehicle-mounted projection display system according to claim 4, characterized in that: The light-transmitting flat plate element is a liquid lens (210); The two opposite plane surfaces (211) of the liquid lens (210) are made of transparent rigid materials, and the peripheral side (212) of the liquid lens (210) is made of flexible material; Under the control of the driving source, the thickness of the liquid lens (210) can be continuously changed, thereby achieving continuous adjustment of the position of the projection surface within the projection distance.

6. The vehicle-mounted projection display system according to claim 5, characterized in that: When the light-transmitting flat plate element is the liquid lens (210), the driving source is used to control the thickness of the liquid lens (210) to continuously change between 0.5 mm and 0.8 mm through voltage or current, thereby forming a continuously changing virtual image with different depths of field within a projection distance of 120 mm to 140 mm.

7. The vehicle-mounted projection display system according to claim 4, characterized in that: The light-transmitting flat plate element is a replaceable glass sheet group (220) with multiple thicknesses; The replaceable multi-thickness glass sheet set (220) comprises a base (224) and a first glass dome (221), a second glass dome (222) and a third glass dome (223) arranged side by side on the base (224), wherein the thickness of each glass dome is different and they are arranged in sequence; Under the control of the driving source, the second glass dome (222) can move relative to the first glass dome (221) or the third glass dome (223) to switch to projection surfaces at three different positions within the projection distance.

8. The vehicle-mounted projection display system according to claim 7, characterized in that: When the light-transmitting flat plate element is a replaceable multi-thickness glass sheet group (220), the driving source is used to control the second glass dome (222) to swap positions with the first glass dome (221) or the third glass dome (223) through electromagnetic signals, thereby realizing a display virtual image on any one of the three projection surfaces within a projection distance of 120 mm to 140 mm; The thicknesses T of the first glass dome (221), the second glass dome (222) and the third glass dome (223) satisfy 0.5 mm ≤ T ≤ 1.8 mm, and are not equal to each other.

9. The vehicle-mounted projection display system according to claim 4, characterized in that: The light-transmitting flat plate element is a pluggable glass compensation plate (230); The pluggable glass compensation sheet (230) can be inserted or removed in the optical path between the equivalent prism (140) and the display chip (150) under the drive of the driving source, so as to realize simultaneous or separate display of virtual images on projection surfaces at two different positions within the projection distance.

10. The vehicle-mounted projection display system according to claim 9, characterized in that: The pluggable glass compensation sheet (230) is a glass sheet, and its thickness D satisfies: 0.3 mm≤D≤1.5 mm; The pluggable glass compensation sheet (230) has at least three states relative to the display chip (150): In a first state, the pluggable glass compensation sheet (230) is completely located outside the optical path between the equivalent prism (140) and the display chip (150); In a second state, the pluggable glass compensation sheet (230) is partially inserted into the optical path between the equivalent prism (140) and the display chip (150); In a third state, the pluggable glass compensation sheet (230) is completely inserted into the optical path between the equivalent prism (140) and the display chip (150), and its center is located on the optical axis; The driving source mechanically controls the pluggable glass compensation sheet (230) to switch between the above three states, thereby realizing the simultaneous or separate display of virtual images on two projection surfaces with a projection distance between 120 mm and 140 mm.

11. The vehicle-mounted projection display system according to any one of claims 1 to 10, characterized in that: The first lens group (110) comprises a first lens (111), a second lens (112) and a third lens (113) which are sequentially arranged along the optical axis; The second lens group (120) comprises a fourth lens (121), a fifth lens (122), a sixth lens (123) and a seventh lens (124) which are sequentially arranged along the optical axis; The aperture (130) is located between the third lens (113) and the fourth lens (121), and the equivalent prism (140) and the display chip (150) are located on a side of the seventh lens (124) away from the sixth lens (123).

12. The vehicle-mounted projection display system according to claim 11, characterized in that: The fourth lens (121) and the fifth lens (122) are bonded together to form a bonded lens; The first lens (111) and the seventh lens (124) are aspherical lenses.

13. A vehicle-mounted HUD system, characterized in that: include: The vehicle-mounted projection display system according to any one of claims 1 to 12.

14. A vehicle, characterized in that: include: The vehicle-mounted HUD system as claimed in claim 13.

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