Head-up display system based on optical zoom

Abstract

The invention discloses an optical zoom head-up display system which comprises a windshield and a zoom imaging system, and the zoom imaging system is composed of an imaging display unit, an optical zoom module, a secondary reflector and a main reflector. Light is emitted from the imaging display unit, is subjected to focal length modulation through the optical zoom module, and is reflected to the position of a driver eye box through the secondary reflector, the main reflector and the windshield in sequence, so that a virtual image with an adjustable imaging distance is formed. The optical zoom module realizes dynamic adjustment of focal length through an Alvarez free-form surface lens or a liquid lens, acquires distance information of a front vehicle in real time by combining with a vehicle-mounted sensor, and synchronously adjusts a virtual image display distance (continuously adjustable in 5-20m), so that a virtual image is attached to a background scene, and visual fatigue is reduced. The system adopts a compact design, the zoom function is concentrated in the optical module, volume expansion and adaptive vehicle-mounted space limitation caused by a traditional mechanical structure are avoided, and the driving safety and comfort are improved.

Description

Technical Field

[0001] The present invention relates to the field of new display technologies, and specifically to a head-up display system based on optical zoom, which is suitable for vehicle-mounted, airborne and other head-up display scenarios, realizes human eye visual fusion by dynamically adjusting the virtual image distance, and improves driving safety and information interaction efficiency. Background Art

[0002] The Head-Up Display (HUD) system, also known as the head-up display system, refers to a display system that projects the image in the form of a virtual image to the center of the driver's field of vision through optical elements. It can project driving status, navigation, assisted driving and other information directly in front of the driver and passengers. The driver can intuitively feel the driving status and other information without switching his or her line of sight, which greatly reduces blind driving time and improves driving safety.

[0003] At present, most HUD systems are reflective off-axis optical systems. The entire system is usually composed of an image source (PGU), a reflector group, and a display medium (windshield). According to the order of development, it can be roughly divided into C HUD, WHUD, and AR HUD. At present, the virtual image projection distance of traditional HUD is fixed, but the distance between the driver's vehicle and the vehicle in front cannot always be fixed. If the HUD virtual image distance is far, when the driving vehicle is close to the vehicle in front, the driver will clearly feel that the image displayed by the HUD passes through the vehicle in front. At this time, the driver faces two pictures with different focal lengths, one virtual and one real. Frequent changes in eye focus will aggravate visual fatigue. This situation is particularly obvious when driving in the city.

[0004] In summary, the virtual image distance of the traditional head-up display (HUD) system is fixed, which causes the driver to frequently adjust the visual focus when the distance between the vehicle and the vehicle in front changes, which can easily cause visual fatigue. Existing zoom solutions mostly rely on mechanical structures to adjust the position of the reflector, resulting in a bulky system and complex thermal management. The present invention achieves adaptive adjustment of the virtual image distance through the integrated design of the optical zoom module combined with dynamic sensor feedback to solve the above problems. Summary of the invention

[0005] Purpose of the invention: In view of the above existing background, the present invention proposes a head-up display system based on optical zoom, which can adjust the virtual image display distance in real time according to the relative position of the real scene in front and the vehicle body. The system adopts a compact design to reduce the optical volume of the system and adapt to the vehicle space limitations.

[0006] Technical solution: A head-up display system based on optical zoom, including a windshield and a zoom imaging system, the zoom imaging system including an imaging display unit, an optical zoom module, a secondary reflector and a main reflector, a main reflector is arranged between the secondary reflector and the windshield, a secondary reflector is arranged between the main reflector and the optical zoom module, and an optical zoom module is arranged between the secondary reflector and the imaging display unit. Light is emitted from the imaging display unit, and the focal length is modulated by the optical zoom module, and then passes through the secondary reflector and the main reflector in sequence, and finally reflects to the driver's eye box position through the windshield, and the driver sees an enlarged virtual image with adjustable imaging distance. The optical zoom module adjusts the light path by changing the internal structure, and finally realizes the adjustment of the focal length of the head-up display system, thereby changing the imaging distance. The present invention can adjust the virtual image display distance in real time according to the relative position of the front vehicle or background scenery and the vehicle body, so as to achieve a close display, which can effectively reduce the visual fatigue caused by the inability of the virtual image and the actual background to effectively merge when the driver views the HUD display content during driving, and enhance driving safety.

[0007] Furthermore, the imaging display unit is a direct display screen or realizes wavefront modulation through optical engine projection combined with a diffuser, and supports LCD, OLED or DLP light sources.

[0008] Furthermore, the optical zoom module adopts an Alvarez free-form surface lens or a liquid lens; the Alvarez free-form surface lens controls the change of its free-form surface shape through a mechanical structure, and the liquid lens changes the lens shape and optical focal length by applying voltage or current.

[0009] Furthermore, the virtual image display distance is continuously adjustable from 5 to 20 meters, and the adjustment is based on the distance information of the preceding vehicle or the background scene acquired in real time by the vehicle-mounted laser radar, infrared detector or camera.

[0010] Furthermore, the surface parameters of the primary reflector and the secondary reflector match the free-form surface of the optical zoom module to reduce optical path distortion and ensure virtual image clarity.

[0011] Furthermore, the system is integrated into a vehicle-mounted HUD device, and a virtual image is projected onto a designated area of ​​the windshield. The virtual image is 5-20 meters away from the driver's eye box, and the parallax angle with the background scene is less than 0.5°.

[0012] Furthermore, the working band of the optical zoom module covers the visible light range (400-700nm) and supports RGB three-color light source mixed imaging.

[0013] Furthermore, the system supports dynamic focus compensation, has a response time of less than 50ms, and is adaptable to vehicle speed changes ranging from 0 to 120km / h.

[0014] Furthermore, the system is embedded in an airborne display device for a pilot's head-up display, and the adjustable range of the virtual image distance is extended to 10-50m, which is suitable for aviation low-altitude flight scenarios.

[0015] Furthermore, the system is linked with the vehicle-mounted ADAS (Advanced Driver Assistance System) to automatically adjust the position and distance of the virtual image display content according to the navigation information to achieve AR navigation enhanced display.

[0016] Beneficial effects: Compared with the prior art, the optical zoom head-up display system in the present invention can effectively reduce the visual fatigue caused by the inability of the driver to effectively integrate the virtual image and the actual background when watching the HUD display content during driving, thereby enhancing driving safety. Compared with the traditional instrument panel, there is no need for the driver to switch the field of view to view the driving information, which improves the driver's concentration and ensures driving safety. At the same time, the compact optical zoom module can solve the problem of the large volume of the mechanical compensation structure of the traditional mechanical zoom structure. The present invention concentrates the realization of the zoom function inside the optical zoom module, saving the volume increase caused by the traditional zoom function, and is more friendly to the in-vehicle structure design of the car company. The virtual image distance of the present invention is continuously adjustable, the response speed is fast (<50ms), the volume is compact, and it is compatible with multiple light sources and multiple scene applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the optical path structure of the system;

[0018] Figure 2 This is the Alvarez lens zoom principle diagram;

[0019] Figure 3 This is a schematic diagram of voltage control of the liquid lens;

[0020] Among them, 1-windshield, 2-primary reflector, 3-secondary reflector, 4-eye box position, 5-imaging display unit, 6-optical zoom module. DETAILED DESCRIPTION

[0021] The present invention will be further explained below in conjunction with the accompanying drawings.

[0022] Example 1

[0023] In this embodiment, the head-up display system is applied to a vehicle-mounted display scenario.

[0024] like Figure 1As shown, the head-up display system includes a windshield 1 and a zoom imaging system, wherein the zoom imaging system includes an imaging display unit 5, an optical zoom module 6, a secondary reflector 3 and a main reflector 2, wherein a main reflector 2 is provided between the secondary reflector 3 and the windshield 1, a secondary reflector 3 is provided between the main reflector 2 and the optical zoom module 6, and an optical zoom module 6 is provided between the secondary reflector 3 and the imaging display unit 5. Light is emitted from the imaging display unit 5, and is focally modulated by the optical zoom module 6, and then sequentially passes through the secondary reflector 3 and the main reflector 2, and finally is reflected by the windshield 1 to the position of the driver's eye box 4, and the driver sees an enlarged virtual image with an adjustable imaging distance. The optical zoom module 6 adjusts the light path by changing the internal structure, and finally realizes the adjustment of the focal length of the head-up display system, thereby changing the imaging distance.

[0025] The primary reflector 2 adopts an aspherical design to match the free-form surface of the Alvarez lens. The optical path simulation shows that the distortion rate is less than 0.3% and the MTF value is greater than 0.5 at 40lp / mm.

[0026] The system is integrated into the vehicle's HUD, and the virtual image is projected onto the middle of the windshield. The operating band covers RGB light sources (450nm, 530nm, 630nm), and the color gamut covers 95% of sRGB.

[0027] like Figure 1 As shown, in this embodiment, the light is emitted by the imaging display unit 5, and the imaging display unit is a direct display type TFT liquid crystal screen. In addition to this embodiment, it includes but is not limited to the form of optical engine projection + diffuser as the light source.

[0028] like Figure 1 As shown, in this embodiment, the optical zoom module is disposed between the secondary reflector 3 and the imaging display unit 5 , and the light emitted by the imaging display unit is modulated by the optical zoom module 6 .

[0029] like Figure 1 and Figure 2 As shown, in this embodiment, the optical zoom module 6 uses an Alvarez lens as a zoom element. During the design process, the free-form surface (Alvarez lens) is matched with other surfaces (primary reflector 2 and secondary reflector 3) of the actual head-up display system. During the actual driving process, the Alvarez lens is controlled by a mechanical structure to change its optical power, focal length and working distance, and finally magnified and displayed through the secondary reflector 3 and the primary reflector 2. Preferably, the Alvarez lens controls the lateral displacement through a motor, thereby changing the Alvarez lens's ability to regulate light and realizing continuous adjustment of the focal length.

[0030] like Figure 1 and Figure 2As shown, in this embodiment, the zoom function is adjusted through the internal structure of the optical zoom module 6, and finally the focal length of the head-up display system is adjusted, thereby changing the imaging distance. At present, other technical solutions for zoom head-up display are mostly realized by mechanically changing the relative position between the primary reflector and the secondary reflector or the relative position between the secondary reflector and the imaging unit. However, mechanical structure control will lead to problems such as increased volume of the overall vehicle machine and increased difficulty in thermal management. The present invention concentrates the realization of the zoom function inside the optical zoom module, saving the volume increase caused by the traditional zoom function, and is more friendly to the in-vehicle structure design of automobile companies.

[0031] like Figure 1 As shown, in this embodiment, the imaging distance of the head-up display system is continuously adjustable from 5-20m from the driver's eye box position to the virtual image imaging focal plane position S2, and can be adjusted to the imaging focal plane S1 at 5m at the closest, and the imaging focal plane S3 at 20m at the farthest. This range can basically meet the distance range requirements between the vehicle body itself and the nearest vehicle or background scenery in the front field of view under normal driving conditions.

[0032] like Figure 1 As shown, in this embodiment, the imaging focal plane S2 of the head-up display system can adjust the virtual image display distance in real time according to the relative position of the front vehicle or background scene and the vehicle body, so that the virtual image and the real background are displayed in close contact, so as to reduce the focal length conflict caused by human eye observation when the imaging virtual image and the actual scene are not in close contact.

[0033] like Figure 1 As shown, in this embodiment, the imaging distance S2 is adjusted according to the distance between the vehicle and the scene or vehicle in front, using a vehicle-mounted laser radar or a front infrared probe to identify the distance to the front vehicle in real time, and then cooperate with the head-up display system to control the optical zoom module to achieve the image fit of the front vehicle. The vehicle-mounted laser radar or the front infrared probe detects the distance to the front vehicle in real time, and transmits the signal to the control unit, driving the optical zoom module 6 to adjust the focal length, so that the virtual image display distance is synchronized with the position of the front vehicle (such as 10m→15m), reducing visual conflicts.

[0034] The head-up display zoom compensation system of the present invention has at least the following beneficial effects:

[0035] First, it effectively reduces the visual fatigue caused by the inability of the virtual image and the actual background to be effectively integrated when the driver is viewing the HUD display content during driving, and enhances driving safety. Compared with traditional instrument panels, the driver does not need to switch the field of view to view driving information, which improves the driver's concentration and ensures driving safety.

[0036] Second, the realization of the zoom function is concentrated inside the optical zoom module, saving the volume increase caused by the traditional zoom function and being more friendly to the in-vehicle structure design of automobile companies.

[0037] Example 2

[0038] In this embodiment, the head-up display system is applied to an airborne display scenario.

[0039] The system supports dynamic focus compensation, has a response time of less than 50ms, and is adaptable to vehicle speed changes ranging from 0 to 120km / h.

[0040] The system is embedded in an airborne display device for a pilot's head-up display, and the adjustable range of the virtual image distance is extended to 10-50m, which is suitable for aviation low-altitude flight scenarios.

[0041] The system is linked with the vehicle-mounted ADAS (Advanced Driver Assistance System) to automatically adjust the position and distance of the virtual image display content according to the navigation information to achieve AR navigation enhanced display. AR arrows are superimposed in the virtual image according to the navigation path, and the virtual image distance is dynamically adjusted with the curve radius (for example, when the curve radius is 50m, the virtual image distance is set to 20m), which improves the intuitiveness of navigation.

Claims

1. A head-up display system based on optical zoom, characterized in that: The invention comprises a windshield (1) and a zoom imaging system; the zoom imaging system comprises an imaging display unit (5), an optical zoom module (6), a secondary reflector (3) and a main reflector (2); light is emitted from the imaging display unit (5), is focal-length-modulated by the optical zoom module (6), passes through the secondary reflector (3) and the main reflector (2) in sequence, and is finally reflected by the windshield (1) to a driver's eye box position (4), thereby forming a virtual image with an adjustable imaging distance; The optical zoom module (6) dynamically adjusts the light path through an internal structure to achieve continuous adjustment of the virtual image display distance.

2. The head-up display system based on optical zoom according to claim 1, characterized in that: The imaging display unit (5) is a direct display screen or realizes wavefront modulation through optical engine projection combined with a diffuser, and supports LCD, OLED or DLP light sources.

3. The head-up display system based on optical zoom according to claim 1, characterized in that: The optical zoom module (6) adopts an Alvarez free-form surface lens or a liquid lens; the Alvarez free-form surface lens controls the change of its free-form surface shape through a mechanical structure, and the liquid lens changes the lens shape and optical focal length by applying voltage or current.

4. The head-up display system based on optical zoom according to claim 1, characterized in that: The virtual image display distance is continuously adjustable from 5 to 20 meters, and the adjustment is based on the distance information of the preceding vehicle or background scene acquired in real time by the vehicle-mounted laser radar, infrared detector or camera.

5. The head-up display system based on optical zoom according to claim 1, characterized in that: The curved surface parameters of the primary reflector (2) and the secondary reflector (3) match the free-form surface of the optical zoom module (6) to reduce optical path distortion and ensure virtual image clarity.

6. The head-up display system based on optical zoom according to claim 1, characterized in that: The system is integrated into a vehicle-mounted HUD device, and a virtual image is projected onto a designated area of ​​a windshield (1). The virtual image is 5-20 meters away from a driver's eye box (4), and the parallax angle with the background scene is less than 0.5°.

7. The head-up display system based on optical zoom according to claim 1, characterized in that: The working wavelength band of the optical zoom module (6) covers the visible light range (400-700 nm) and supports RGB three-color light source mixed imaging.

8. The head-up display system based on optical zoom according to claim 1, characterized in that: The system supports dynamic focus compensation, has a response time of less than 50ms, and is adaptable to vehicle speed changes ranging from 0 to 120km / h.

9. The head-up display system based on optical zoom according to claim 1, characterized in that: The system is embedded in an airborne display device for a pilot's head-up display, and the adjustable range of the virtual image distance is extended to 10-50m, which is suitable for aviation low-altitude flight scenarios.

10. The head-up display system based on optical zoom according to claim 1, characterized in that: The system is linked with the vehicle-mounted ADAS (Advanced Driver Assistance System) to automatically adjust the position and distance of the virtual image display content according to the navigation information, thereby realizing AR navigation enhanced display.

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