AR-HUD for vehicle-mounted optical waveguide transmission

Abstract

The invention provides an AR-HUD (Auto Register-Head Up Display) design for vehicle-mounted optical waveguide transmission. The optical system is characterized in that a windshield, PMMA (polymethyl methacrylate), a holographic surface 2, a reflector 1, a reflector 2, a reflector 3, a reflector 4, a coupling-out surface and an image surface are sequentially distributed from an object surface to an image surface, light from the image surface is coupled into an optical waveguide formed by the reflectors after being reflected by the windshield, and the holographic surface 2 is embedded into the optical waveguide. Imaging is obtained by adjusting parameters such as the angle and the distance of the system, and according to the principle of reversibility of an optical path, the actual imaging situation is combined with an external scene through a windshield. The method can be used for displaying the display information and the external information in a combined manner, and can be widely applied to the field of vehicle-mounted AR-HUD.

Description

(I) Technical field

[0001] The present invention relates to an AR-HUD with vehicle-mounted optical waveguide transmission, belonging to the technical field of optical imaging lenses. (II) Background technology

[0002] The car head-up display (HUD) projects the navigation route, gear information and speed information in the instrument panel onto the windshield through the light source emitted by the HUD, or forms virtual navigation information in front, so that the driver can obtain relevant information without lowering his head and observing the front normally. The existing car head-up display systems include C-HUD, W-HUD, and AR-HUD. The current mainstream HUDs are mainly of two types: W-HUD (Windshield HUD) and AR-HUD (Augmented Reality HUD). W-HUD projects light onto the windshield through the principle of optical projection, and the driver only needs to observe the information on the windshield. AR-HUD uses augmented reality technology to superimpose virtual image information and real-time information on actual road conditions, allowing drivers to obtain information more directly.

[0003] The first use of HUDs was in the 1950s for aiming and shooting. In 1960, the Hawker Siddeley Buccaneer first used head-up display technology in military aircraft. In 1970, HUDs were used in commercial aviation. Waveguide combiners are an old concept, with some of the earliest IP dating back to 1976 and applied to HUDs. A patent obtained in 1987 by Juris Upatnieks, a Latvian / American scientist and one of the pioneers of modern holography, implemented it in a dichromium gelatin (DCG) holographic medium. A few years later, the 1DEPE architecture and various alternatives to input and output coupler technology were proposed, such as the surface relief grating coupler of Thomson CSF. Pierre-Alexandre Blanche proposed the basic theoretical framework for how curved waveguides can be used for AR / HUD in 2021, arguing that combiners using planar waveguides are indeed seamlessly integrated in front of the viewer's eyes.

[0004] In recent years, along with the wave of AR technology, many companies have devoted themselves to the development of AR near-eye display devices. Optical waveguides have become the mainstream way to modulate light beams in AR near-eye display devices due to their excellent characteristics. Each optical waveguide solution has its own advantages and disadvantages. At present, geometric optical waveguides have a wide range of applications and excellent results, but the manufacturing process is complicated, it is difficult to meet ideal conditions, and the output rate is relatively low. Diffraction optical waveguides, as non-traditional optical elements, have higher degrees of freedom in design and preparation than geometric optical waveguides, but there are problems such as low field of view and dispersion. At the same time, the design process is relatively difficult, and the structure needs to be continuously optimized to obtain higher diffraction efficiency and better imaging quality.

[0005] In order to solve the above problems, the present invention proposes a vehicle-mounted optical waveguide transmission AR-HUD research scheme. Compared with the traditional HUD structure, the imaging structure is optimized and the optical system is designed using a holographic surface. (III) Summary of the invention

[0006] The object of the present invention is to provide a design scheme for a vehicle-mounted AR-HUD optical system propagating through an optical waveguide.

[0007] The object of the present invention is achieved in that:

[0008] A vehicle-mounted AR-HUD with optical waveguide transmission, the system comprising: holographic surface 2, coupling surface, coupling surface, reflector 1, reflector 2, reflector 3, reflector 4, windshield, image surface, object surface. The order of the lenses from the object surface to the image surface is: object surface, windshield, coupling surface, holographic surface 2, reflector 1, reflector 2, reflector 3, reflector 4, coupling surface, image surface.

[0009] In a specific implementation example of the present invention, the distance between the object plane and the windshield is 650 mm.

[0010] In a specific implementation example of the present invention, the windshield is designed using an extended polynomial, the maximum number of terms of the extended polynomial is 5, the normalized radius is 1000, X1Y0 is 0, X0Y1 is 0, X2Y0 is -90, X1Y1 is 0, and X0Y2 is -25.

[0011] In a specific implementation example of the present invention, the distance between the windshield and the coupling surface is 300 mm, the coupling surface material is PMMA material, PMMA material is the main constituent material of the waveguide, and the windshield will cause a change in the propagation direction of light.

[0012] In a specific implementation example of the present invention, the coupling surface is 15 mm away from the holographic surface 2, and the holographic surface 2 is tilted around the X-axis with a tilt angle of 45°. The tilt of the holographic surface 2 will cause a change in the propagation direction of light.

[0013] In a specific implementation example of the present invention, the recording point X1 of the holographic surface 2 is 0, and the recording point Y1 is -1×10 8 , the recording point Z1 is -1×10 8 , the recorded point X2 is 0, the recorded point Y2 is 0, the recorded point Z2 is 300, and the recorded wavelength is 0.368.

[0014] In a specific implementation example of the present invention, the distance between the holographic surface 2 and the reflector 1 is 30 mm, and the reflector 1 is eccentric in the Y direction, and the eccentric distance is 13.415 mm.

[0015] In a specific implementation example of the present invention, the distance between the reflector 1 and the reflector 2 is 30 mm. The reflector 2 is eccentric in the Y direction, and the eccentric distance is 26.954 mm.

[0016] In a specific implementation example of the present invention, the distance between the reflector 2 and the reflector 3 is 30 mm, and the reflector 3 is eccentric in the Y direction, and the eccentric distance is 26.954 mm.

[0017] In a specific implementation example of the present invention, the distance between the reflector 3 and the reflector 4 is 30 mm, and the reflector 4 is eccentric in the Y direction, and the eccentric distance is 26.954 mm.

[0018] The distances between reflectors 1, 2, 3 and 4 determine that the thickness of the optical waveguide is 30 mm.

[0019] In a specific implementation example of the present invention, the reflector 4 is 13 mm away from the outcoupling surface, and the outcoupling surface is tilted around the X-axis with a tilt angle of 50°. The tilt of the outcoupling surface will cause a change in the propagation direction of light.

[0020] After adopting the above scheme, the advantages of the present invention are as follows:

[0021] The ultra-thin structure of optical waveguide technology significantly reduces the size of AR-HUD. This advantage makes it easier to install AR-HUD in small spaces in the car, such as behind the dashboard, providing greater flexibility in cockpit design. Optical waveguide technology uses the principle of total internal reflection to achieve efficient transmission of optical signals, ensuring that there is no loss or leakage of images during transmission. This feature enables AR-HUD to present a clearer and more realistic virtual image effect. At the same time, optical waveguide technology can also achieve accurate positioning and high-definition display of images, providing drivers with a more realistic and intuitive driving experience. The introduction of optical waveguide technology reduces the manufacturing cost of AR-HUD. Due to the elimination of the complex reflector design, the optical waveguide structure is relatively simple and the manufacturing process is easier. (IV) Description of the drawings

[0022] Figure 1 This is a schematic diagram of the lens structure of the AR-HUD with vehicle-mounted optical waveguide transmission of the present invention;

[0023] Figure 2 This is the AR-HUD diffusion pattern transmitted by the vehicle-mounted optical waveguide of the present invention (V) Specific implementation plan

[0024] The present invention will be further described below in conjunction with specific embodiments.

[0025] Figure 1 It is a schematic diagram of the overall structure of the present invention, as shown in Figure 1 As shown in the figure, the AR-HUD of the vehicle-mounted optical waveguide transmission includes: holographic surface 2, coupling surface, coupling surface, reflector 1, reflector 2, reflector 3, reflector 4, windshield, image plane, object plane. The lens sequence from object plane to image plane is: object plane, windshield, coupling surface, holographic surface 2, reflector 1, reflector 2, reflector 3, reflector 4, coupling surface, image plane.

[0026] The following is a specific implementation example: In the following text description and table, lens 1 is the extended polynomial, lens 2 is the coupling surface, lens 3 is the holographic surface 2, lens 4 is the reflector 1, lens 5 is the reflector 2, lens 6 is the reflector 3, lens 7 is the reflector 4, and lens 8 is the coupling surface.

[0027] Among them, lens 1 is an extended polynomial, the maximum number of terms of the extended polynomial is 5, the normalized radius is 1000, X1Y0 is 0, X0Y1 is 0, X2Y0 is -90, X1Y1 is 0, and X0Y2 is -25.

[0028] The lens 3 is the holographic surface 2, the recording point X1 of the holographic surface 2 is 0, and the recording point Y1 is -1×10 8 , the recording point Z1 is -1×10 8 , the recorded point X2 is 0, the recorded point Y2 is 0, the recorded point Z2 is 300, and the recorded wavelength is 0.368.

[0029] In Table 1, surface 1 is the object plane, and the center distance between it and surface 2 is 650 mm, which is the center thickness of surface 1.

[0030] In Table 1, surface 2 is a coordinate discontinuity surface, tilted 45° around X.

[0031] In Table 1, surface 3 is lens 1, the radius of curvature is infinite, and the material is MIRROR.

[0032] In Table 1, surface 4 is a coordinate discontinuity surface, and the center distance between it and surface 5 is 300 mm. Due to the rotation of the optical axis, the center thickness of surface 4 is -300 mm, and surface 4 is inclined by -45° around X.

[0033] In Table 1, surface 5 is a coordinate discontinuity surface, and due to the rotation of the optical axis, the eccentricity in the Y direction is -18.919 mm.

[0034] In Table 1, surface 6 is lens 2, the radius of curvature is infinite, the material is PMMA, and the center distance with surface 7 is 15 mm. Due to the rotation of the optical axis, the center thickness of surface 6 is -15 mm.

[0035] In Table 1, surface 7 is a coordinate discontinuity surface, tilted at -45° around the X-axis.

[0036] In Table 1, surface 8 is lens 3, the radius of curvature is infinite, and the material is MIRROR.

[0037] In Table 1, surface 9 is a coordinate discontinuity surface, and the center distance between surface 9 and surface 10 is 15 mm, which is the center thickness of surface 9.

[0038] In Table 1, surface 10 is a coordinate discontinuity surface, and the eccentricity in the Y direction is 13.415 mm.

[0039] In Table 1, surface 11 is lens 4, the radius of curvature is infinite, the material is MIRROR, and the center distance between surface 11 and surface 12 is 30 mm. Due to the rotation of the optical axis, the center thickness of surface 11 is -30 mm.

[0040] In Table 1, surface 12 is a coordinate discontinuity surface, and the eccentricity in the Y direction is 26.954 mm.

[0041] In Table 1, surface 13 is lens 5, the radius of curvature is infinite, the material is MIRROR, and the center distance between surface 13 and surface 14 is 30 mm, which is the center thickness of surface 13.

[0042] In Table 1, surface 14 is a coordinate discontinuity surface, and the eccentricity in the Y direction is 26.954 mm.

[0043] In Table 1, surface 15 is lens 6, the radius of curvature is infinite, the material is MIRROR, and the center distance between surface 15 and surface 16 is 30 mm. Due to the rotation of the optical axis, the center thickness of surface 15 is -30 mm.

[0044] In Table 1, surface 16 is a coordinate discontinuity surface, and the eccentricity in the Y direction is 26.954 mm.

[0045] In Table 1, surface 17 is lens 7, the radius of curvature is infinite, the material is MIRROR, and the center distance between it and surface 18 is 30 mm, which is the center thickness of surface 13.

[0046] In Table 1, surface 18 is a coordinate discontinuity surface, with an eccentricity of 11.680 mm in the Y direction and an inclination of -50° about X.

[0047] In Table 1, surface 19 is lens 8, the radius of curvature is infinite, the material is MIRROR, and the center distance between it and surface 20 is 30 mm, which is the center thickness of surface 13.

[0048] In Table 1, surface 20 is a coordinate discontinuity surface.

[0049] In Table 1, surface 21 is the image surface.

[0050] The type, curvature radius, thickness, material, eccentricity, and inclination angle of each surface are shown in Table 1 below.

[0051] The specific coefficients of the polynomial are shown in Table 2.

[0052] The specific coefficients of holographic surface 2 are shown in Table 3.

[0053] Table 1

[0054]

[0055] Table 2

[0056] Surface type Maximum number of terms Normalized radius X1Y0 X0Y1 X2Y0 X1Y1 X0Y2 Lens 1 5 1000 0 0 -90 0 -25

[0057] Table 3

[0058] Surface type Recording point X1 Record point Y1 Record point Z1 Recording point X2 Record point Y2 Record point Z2 Lens 3 0 <![CDATA[-1×10 8 ]]> <![CDATA[-1×10 8 ]]> 0 0 300

[0059] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a diffuse pattern.

Claims

1. An AR-HUD with on-vehicle optical waveguide transmission, characterized by: It consists of a windshield, a holographic surface 2, a reflector 1, a reflector 2, a reflector 3, a reflector 4, an out-coupling surface, and an image surface. The reflector 1, the reflector 2, the reflector 3, and the reflector 4 are combined to form the transmission part of the optical waveguide, and the holographic surface 2 is embedded in the PMMA material to adjust the light of the coupling part.

2. The vehicle-mounted optical waveguide transmission AR-HUD according to claim 1, characterized in that: Use holographic surface 2 to design the optical system, and design the parameters of holographic surface 2 such as recording point X1, recording point Y1, recording point Z1, recording point X2, recording point Y2, recording point Z2, recording wavelength, and tilt angle.

3. According to the vehicle-mounted optical waveguide transmission AR-HUD of claim 1, the Y eccentricity of the reflector 1, the reflector 2, the reflector 3, the reflector 4, and the outcoupling surface respectively meet the following conditions: The eccentricity of the reflector 1Y is y1, 12.4<y1<13.5; The eccentricity of the reflector 2Y is y2, 25.4<y2<27.0; The eccentricity of the reflector 3Y is y3, 25.4<y3<27.0; The eccentricity of the reflector 4Y is y4, 25.4<y4<27.0; The eccentricity of the coupling surface is y5, 10.5<y4<12.0; The holographic surface 2, the reflector 1, the reflector 2, the reflector 3, the reflector 4 and the outcoupling surface together constitute an optical waveguide transmission module, and the thickness of the optical waveguide is 30 mm.

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