A HUD zoom system

Abstract

The application relates to a HUD zoom system, which comprises a windshield arranged in front of a driver's eye viewing position, an imaging system and an imaging display area, the imaging system comprises an imaging unit, a polarization beamsplitter and a curved zoom unit, the polarization beamsplitter is arranged between the imaging unit and the curved zoom unit, light is emitted from the imaging unit, passes through the polarization beamsplitter, the polarization state P light transmits through the polarization beamsplitter and enters the curved zoom unit, the polarization state is changed to S light after being reflected by the curved zoom unit, the light passes through the polarization beamsplitter again, is reflected by the windshield and is reflected at the driver's eye viewing position, an enlarged image is displayed on the imaging display area, the curved zoom unit is connected with a driving member, the driving member drives the curved zoom unit to change the position of the curved zoom unit in the light path, and the imaging distance can be adjusted. The HUD zoom system has the advantages of compact light path, small volume and adjustable imaging distance.

Description

Technical Field

[0001] This invention relates to the field of head-up display technology, specifically a HUD zoom system. Background Technology

[0002] Head-up displays (HUDs) were first used in military aircraft. In the 1980s, HUDs began to be used in automobiles. HUDs allow drivers to obtain important driving information directly through the windshield without looking down at the instrument panel or center console. HUDs can project information such as current speed and navigation onto the windshield, avoiding blind spots caused by drivers looking down at the instrument panel, thus improving driving safety and convenience.

[0003] Currently, most automotive head-up displays (HUDs) use a single-path optical path, meaning the projection distance is generally fixed. This prevents the projection distance from being adjusted to meet the driver's needs, resulting in a poor user experience. Current display methods include: a WHUD with an projection distance of approximately 2.5m and a virtual image size of about 10 inches; and an ARHUD with an projection distance of approximately 8m and a virtual image size of about 55 inches. Some designs even cater to both low-speed and high-speed driving conditions, offering two projection distances that can display information at different distances individually or simultaneously on both images. Typically, the near view displays standard vehicle speed information, while the far view displays enhanced navigation information.

[0004] However, the driving environment is relatively complex, and drivers often need to observe positions at different distances. When the driver's eye position differs from the position of the projected image displayed on the screen, it is difficult for the driver to observe a clear projected image while simultaneously observing the surrounding environment. In situations requiring warnings, such as when turning or changing lanes, standard vehicle speed and warning information are also integrated. The display may show directional information such as arrows indicating the road ahead, but the actual display effect resembles an animated flying effect, failing to enhance the visual experience and easily causing eye strain. Summary of the Invention

[0005] This invention provides a HUD zoom system with a compact optical path, small size, and adjustable imaging distance.

[0006] To achieve the above objectives, the following technical solutions are employed.

[0007] A head-up display (HUD) zoom system includes a windshield positioned in front of the driver's eye level, an imaging system, and an imaging display area. The imaging system includes an imaging unit, a polarizing beam splitter, and a curved zoom unit. The polarizing beam splitter is located between the imaging unit and the curved zoom unit. Light emitted from the imaging unit passes through the polarizing beam splitter; the polarized P-state light passes through the beam splitter and enters the curved zoom unit. After reflection by the curved zoom unit, the polarization state changes to S-state light. The light is then reflected again by the polarizing beam splitter and enters the windshield for reflection, resulting in a magnified image displayed in the imaging display area at the driver's eye level. The curved zoom unit is connected to a driving component, which drives the curved zoom unit to change its position in the optical path, making the imaging distance adjustable.

[0008] The above technical solution mainly comprises an imaging system consisting of an imaging unit, a polarizing beam splitter, and a curved zoom unit. The imaging unit serves as the image source, emitting light. The light emitted by the imaging unit is polarized and split by the polarizing beam splitter, then enters the curved zoom unit. After passing through the curved zoom unit, the light is reflected and re-enters the polarizing beam splitter. After being split and reflected again by the polarizing beam splitter, the light enters the windshield for imaging. The curved zoom unit is connected to a driving component, which drives the curved zoom unit to adjust its displacement in the optical path, achieving curved zoom. This makes the distance of the image displayed in the imaging display area adjustable, enabling the HUD to display different content in different scenarios and different information at different imaging distances, achieving content displayed at fixed distances or dynamically variable distances, thus increasing driving safety and experience. The HUD zoom system of this invention, by setting a polarizing beam splitter and a free zoom unit in the imaging system, and using a PBS polarizing beam splitter and a catadioptric optical system, allows light to propagate back and forth between optical elements, so that the system can achieve a greater imaging distance and a wider adjustment range in the same space.

[0009] Furthermore, the curved zoom unit is a freeform zoom unit, including a freeform mirror, and the freeform mirror has a waveplate on one side of the polarizing beam splitter.

[0010] In the above technical solution, the curved zoom unit is a freeform zoom unit, which can be set according to the actual scene and working conditions. Specifically, a freeform mirror is used as the main body of the curved zoom. The curved opening direction of the freeform mirror is located on the side facing the polarizing beam splitter, and a wave plate is set on the opening side. It is made of birefringent material. The setting of the wave plate causes the two mutually orthogonal polarization components to produce a phase shift, which can be used to adjust the polarization state of the beam.

[0011] Furthermore, the waveplate is made of a thin film material and is deposited onto the reflective surface of the freeform mirror through a coating process.

[0012] In the above technical solution, a coating process is used to deposit waveplates onto a freeform surface mirror. The waveplates and the freeform surface mirror are stably bonded, resulting in a more compact optical path. Moreover, it has a large wavelength bandwidth, a wider range of display colors, and higher brightness.

[0013] Furthermore, the freeform surface mirror is connected to a driving component, which drives the freeform surface mirror to move axially along a direction parallel to the propagation direction of light.

[0014] In the above technical solution, the driving component drives the freeform surface mirror to move axially along the direction parallel to the propagation of light, that is, the driving component drives the freeform surface mirror to make linear displacement. The driving component adopts step-type drive to make the movement process of the freeform surface mirror stable, ensure clear imaging display, and thus improve the driver's viewing experience.

[0015] Furthermore, when the freeform surface mirror is in the first optical path position, the second optical path position, or the third optical path position in the optical path, the imaging display area displays a magnified image at the first imaging position, the second imaging position, or the third imaging position, respectively. The first imaging position, the second imaging position, and the third imaging position correspond to the first optical path position, the second optical path position, and the third optical path position, respectively.

[0016] In the above technical solution, the first imaging position is the farthest imaging position, the third imaging position is the closest imaging position, and the second imaging position is the middle imaging position. When the driving component drives the freeform surface mirror to the first, second, and third optical path positions respectively, the light is reflected by the freeform surface zoom unit and then enters the polarizing beam splitter for beam splitting and reflection. It then enters the windshield and forms images at the farthest imaging position (i.e., the first imaging position), the middle imaging position (i.e., the second imaging position), and the closest imaging position (i.e., the third imaging position) in the imaging area. In addition to the above three imaging positions, imaging can also be performed between the first and third imaging positions, which is convenient for the driver to observe and improves the driver's viewing experience.

[0017] Furthermore, the light emitted from the imaging unit passes through a polarizing beam splitter and becomes polarized P-beam before entering a waveplate, which is a quarter-wave plate. After passing through the quarter-wave plate, the light enters a freeform mirror. After being reflected by the freeform mirror, the light passes through the quarter-wave plate again, and its polarization state changes to S-beam. The S-beam then enters the windshield and, after being reflected by the windshield, displays a magnified image in the imaging display area.

[0018] In the above technical solution, after the light passes through the polarizing beam splitter, it enters the quarter-wave plate as polarized P-light. After being reflected by the freeform mirror and the quarter-wave plate, the polarization state of the light becomes S-light. After being split and reflected again by the polarizing beam splitter, the polarized S-light enters the windshield. This method of using a polarizing beam splitter and setting a wave plate on the freeform mirror realizes the change of the light's vibration state. At the same time, it allows the light to enter the windshield after beam splitting and multiple reflections, making the optical path structure compact. This results in a small overall system size and space occupation, while also enabling adjustment of the imaging distance.

[0019] Furthermore, the imaging unit is any projection module of DLP, LOCS, LCD, or laser scanning LBS.

[0020] In the above technical solutions, projection modules such as DLP, LOCS, LCD, or laser scanning LBS are all common projection modules with mature projection technologies, making the projection imaging of this technical solution more stable and clear, thereby ensuring the driver's viewing experience.

[0021] Furthermore, the imaging unit utilizes a polarization polarization device to polarize the light passing through the imaging unit, making the polarized light P-polarized.

[0022] In the above technical solution, when the light emitted by the imaging unit is polarized by a polarization device, the light emitted by the imaging unit is polarized into a P-state light and enters the polarization beam splitter. After the polarization P-state light enters the polarization beam splitter, it is split by the vibration of the polarization beam splitter and outputs the polarization P-state light, so that the polarization P-state light enters the freeform zoom unit.

[0023] Furthermore, the polarization device is a half-wave plate.

[0024] In the above technical solution, the polarization device is a half-wave plate. The function of the half-wave plate is to reduce reflected light and increase transmitted light, thereby increasing the amount of light entering the polarization beam splitter and ensuring image quality.

[0025] Furthermore, the imaging display area ranges from 3m to 20m.

[0026] In the above technical solution, the imaging display area is a variable area, ranging from 3m to 20m, which allows the system to display different content in different scenarios according to actual needs. Different information is displayed at different imaging distances, enabling the display of content at fixed distances or dynamically variable distances, thereby increasing driving safety.

[0027] Compared with existing technologies, the HUD zoom system of this invention has the following advantages:

[0028] The HUD zoom system of this invention, by setting a polarizing beam splitter and a free zoom unit in the imaging system, and using a PBS polarizing beam splitter and a catadioptric optical system, allows light to propagate back and forth between optical elements, so that the system can achieve a greater imaging distance and a wider adjustment range in the same space. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structural distribution of Embodiment 1 of the HUD zoom system of the present invention;

[0030] Figure 2 for Figure 1 A schematic diagram of the structural distribution of the imaging system;

[0031] Figure 3 for Figure 1 A schematic diagram of the specific curved zoom unit of the imaging system;

[0032] Figure 4 for Figure 1 A detailed imaging path diagram of the imaging system;

[0033] Figure 5 This is a flowchart illustrating the polarization state change of the HUD zoom system of the present invention.

[0034] Figure 6 This is a schematic diagram of the structural distribution of Embodiment 2 of the HUD zoom system of the present invention;

[0035] Figure 7 for Figure 6 A schematic diagram of the structural distribution of the imaging system. Detailed Implementation

[0036] The HUD zoom system of the present invention will be described in further detail below with reference to specific embodiments and accompanying drawings.

[0037] Example 1

[0038] Reference Figures 1 to 5According to a non-limiting embodiment of the present invention, a HUD zoom system includes a windshield 3 located in front of the driver's eye viewing position 4, an imaging system 2, and an imaging display area 1. The imaging system 2 includes an imaging unit 21, a polarizing beam splitter 22, and a curved zoom unit 23. The polarizing beam splitter 22 is located between the imaging unit 21 and the curved zoom unit 23. In this embodiment, the imaging unit directly emits light to the polarizing beam splitter. The light emitted from the imaging unit 21 passes through the polarizing beam splitter 22, and the polarized P-state light is transmitted through the polarizing beam splitter 22. The light enters the curved zoom unit 23 via the beam splitter 22. After reflection by the curved zoom unit 23, the polarization state becomes S-ray. The light is then reflected again by the polarizing beam splitter 22 and enters the windshield 3. At the driver's viewing position 4, a magnified image is displayed in the imaging display area 1. The curved zoom unit 23 is connected to a driving component (not shown in the figure). The driving component drives the curved zoom unit 23 to change its position in the optical path. Specifically, the driving component drives the curved zoom unit 23 to move along the MM1 axis, making the imaging distance adjustable. In this embodiment, the driving component is a stepper drive component. Specifically, the driving component preferably has a structure where a stepper motor drives a lead screw, but other stepper drive structures can also be used to ensure the stable operation of the curved zoom unit 23, thereby ensuring image quality. In this technical solution, the imaging system 2 mainly consists of an imaging unit 21, a polarizing beam splitter 22, and a curved zoom unit 23. The imaging unit 21 serves as the image source for emitting light. The light emitted by the imaging unit 21 is polarized and split by the polarizing beam splitter, then enters the curved zoom unit 23. After passing through the curved zoom unit 23, the light is reflected and re-enters the polarizing beam splitter. After being split and reflected by the polarizing beam splitter, the light enters the windshield 3 for imaging. The curved zoom unit 23 is connected to a driving component, which drives the curved zoom unit 23 to adjust its displacement in the optical path, achieving curved zoom. This makes the distance of the image displayed in the imaging display area 1 adjustable, thereby enabling the HUD to display different content in different scenarios and different information at different imaging distances according to actual needs. This allows for the display of content at fixed distances or dynamically variable distances, increasing driving safety and experience. The HUD zoom system of the present invention, by setting a polarizing beam splitter 22 and a free zoom unit in the imaging system 2, and using the PBS polarizing beam splitter 22, adopts a catadioptric optical system, in which light propagates back and forth between optical elements, so that the system can achieve a longer imaging distance and a wider adjustment range in the same space.

[0039] Reference Figures 1 to 4In a non-limiting embodiment of the present invention, the curved zoom unit 23 is a freeform zoom unit, including a freeform mirror. A waveplate 24 is provided on one side of the polarizing beam splitter 22. In this embodiment, the waveplate 24 is a quarter-wave plate. In this technical solution, the curved zoom unit 23 is a freeform zoom unit, which can be set according to the actual scene and working conditions. Specifically, a freeform mirror is used as the main body of the curved zoom. The curved opening direction of the freeform mirror is located on the side facing the polarizing beam splitter 22, and a quarter-wave plate is provided on this opening side. It is made of birefringent material. The setting of the waveplate causes the two mutually orthogonal polarization components to produce a phase shift, which can be used to adjust the polarization state of the beam.

[0040] Reference Figures 1 to 4 In a non-limiting embodiment of the present invention, the waveplate 24 is made of a thin film material and is deposited onto the reflective surface of the freeform mirror using a coating process. In this technical solution, the waveplate 24 is deposited onto the freeform mirror using a coating process, resulting in a stable bond between the waveplate and the freeform mirror, and a large wavelength bandwidth, making the optical path more compact.

[0041] Reference Figures 1 to 4 In a non-limiting embodiment of the present invention, the freeform surface mirror is connected to a driving component, which drives the freeform surface mirror to move axially along a direction parallel to the propagation direction of light. In this technical solution, the driving component drives the freeform surface mirror to move axially along a direction parallel to the propagation direction of light, that is, the driving component drives the freeform surface mirror to perform linear displacement. The driving component adopts a step-by-step drive, which makes the movement of the freeform surface mirror stable, ensuring clear image display and thus improving the driver's viewing experience.

[0042] Reference Figures 1 to 4In a non-limiting embodiment of the present invention, when the freeform surface mirror is in the first optical path position S1, the second optical path position S2, or the third optical path position S3 in the optical path, the imaging display area 1 displays a magnified image in the first imaging position 11, the second imaging position 12, or the third imaging position 13, where the first imaging position 11, the second imaging position 12, and the third imaging position 13 correspond to the first optical path position S1, the second optical path position S2, and the third optical path position S3, respectively. In this technical solution, the first imaging position 11 is the farthest imaging position, the third imaging position 13 is the closest imaging position, and the second imaging position 12 is the middle imaging position. When the driving component drives the freeform surface mirror to the first optical path position S1, the second optical path position S2, and the third optical path position S3 in the optical path, the light is reflected by the freeform surface zoom unit 23 and then enters the polarizing beam splitter 22 for beam splitting and reflection. It then enters the windshield 3 and is imaged at the farthest imaging position, i.e., the first imaging position 11, the middle imaging position, i.e., the second imaging position 12, and the closest imaging position, i.e., the third imaging position 13, in the imaging area. In addition to the above three imaging positions, imaging can be performed between the first imaging position 11 and the third imaging position 13, which is convenient for the driver to observe and improves the driver's viewing experience.

[0043] Reference Figures 1 to 5 In a non-limiting embodiment of the present invention, the light emitted from the imaging unit 21, after passing through the polarizing beam splitter 22, becomes polarized P-light and enters the waveplate, which is a quarter-wave plate. After passing through the quarter-wave plate, the light enters the freeform mirror. After being reflected by the freeform mirror, the light passes through the quarter-wave plate again, and the polarization state of the light becomes S-light. The S-light enters the windshield 3 and is reflected by the windshield 3, displaying a magnified image in the imaging display area 1. In this technical solution, after the light passes through the polarizing beam splitter 22, it enters the quarter-wave plate as polarized P-light. After being reflected by the freeform mirror and the quarter-wave plate, the polarization state of the light changes to S-light. After being split and reflected again by the polarizing beam splitter 22, the polarized S-light enters the windshield 3. This method of using the polarizing beam splitter 22 and setting a wave plate on the freeform mirror realizes the change of the light's vibration state. At the same time, it makes the light enter the windshield 3 after beam splitting and multiple reflections, making the optical path structure compact, thus making the overall system small in size and space-saving, while also enabling the adjustment of the imaging distance.

[0044] Reference Figures 1 to 5 In a non-limiting embodiment of the present invention, the imaging unit 21 is any projection module such as DLP, LOCS, LCD, or laser scanning LBS. In this technical solution, projection modules such as DLP, LOCS, LCD, or laser scanning LBS are all common projection modules with mature projection technologies, making the projection imaging of this technical solution more stable and clear, thereby ensuring the driver's viewing experience.

[0045] Reference Figures 1 to 5 In a non-limiting embodiment of the present invention, the imaging unit 21 utilizes a polarization polarizing device to polarize the light passing through the imaging unit 21, making the polarized light P-polarized. In this technical solution, when the light emitted by the imaging unit 21 is polarized by the polarization polarizing device, the light emitted by the imaging unit 21 enters the polarization beam splitter 22 as P-polarized light. After entering the polarization beam splitter 22, the polarization beam splitter 22 vibrates and splits the light, outputting the polarization beam P-polarized light, which then enters the freeform zoom unit 23.

[0046] Reference Figures 1 to 5 In a non-limiting embodiment of the present invention, the polarization device is a half-wave plate. In this technical solution, the polarization device is a half-wave plate. The function of the half-wave plate is to ensure that the polarization state of the light emitted from the imaging unit 21 is linearly polarized, thereby guaranteeing imaging quality.

[0047] Reference Figures 1 to 5 In a non-limiting embodiment of the present invention, the imaging display area 1 ranges from 3m to 20m. In this technical solution, the imaging display area 1 is a variable area, ranging from 3m to 20m, allowing the system to display different content in different scenarios according to actual needs. Different information can be displayed at different imaging distances, enabling the display of content at fixed distances or dynamically variable distances, thereby increasing driving safety.

[0048] Example 2

[0049] Reference Figure 6 and Figure 7This invention provides a non-limiting embodiment. This embodiment is basically the same in structure and principle as Embodiment 1, except that an optical path deflection is added to the imaging unit. Specifically, this embodiment provides a HUD zoom system, including a windshield 3A located in front of the driver's eye viewing position 4A, an imaging system 2A, and an imaging display area 1A. The imaging system 2A includes an imaging unit, a polarizing beam splitter 22A, and a curved zoom unit 23A. The polarizing beam splitter 22A is located between the imaging unit and the curved zoom unit 23A. The imaging unit consists of an imaging image source 20A and a primary reflector 21A. The primary reflector 21A is located between the polarizing beam splitter 22A and the imaging image source 20A. The curved zoom unit 23A is connected to a driving component. In this embodiment, the primary reflector 21A is a plane reflector or a freeform mirror capable of correcting aberrations. Light is emitted from the imaging source 20A to the primary reflector 21A, and after a first reflection by the primary reflector 21A, it reaches the polarizing beam splitter. After passing through the polarizing beam splitter 22, the polarized P-state light passes through the polarizing beam splitter 22 and enters the curved zoom unit 23. The curved zoom unit 23 performs a second reflection on the light. The light after the second reflection passes through the polarizing beam splitter 22 again, and the polarization state becomes S-state light. After being reflected again by the polarizing beam splitter 22, it enters the windshield 3 and is reflected, resulting in a magnified image displayed in the imaging display area 1 at the driver's eye viewing position 4. The curved zoom unit 23 is connected to a driving component (not shown in the figure), which drives the curved zoom unit 23 to change its position in the optical path, making the imaging distance adjustable. This embodiment improves the imaging unit by adding a first optical path reflection, making the overall optical path structure more compact and smaller in size.

[0050] In the description of this invention, it should be understood that terms such as "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0052] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0053] The above embodiments are merely specific examples of the present invention, and their descriptions are quite specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these obvious substitutions all fall within the protection scope of the present invention.

Claims

1. A HUD zoom system comprising a windshield positioned in front of a driver's eye viewing position, characterized in that: The imaging system comprises an imaging unit, a polarizing beamsplitter and a curved zoom unit, the polarizing beamsplitter is located between the imaging unit and the curved zoom unit, the light rays are emitted from the imaging unit, pass through the polarizing beamsplitter, the polarizing state P light transmits through the polarizing beamsplitter and enters the curved zoom unit, the polarizing state is changed to S light after being reflected by the curved zoom unit, the light rays pass through the polarizing beamsplitter again and are reflected by the windshield, an enlarged image is displayed on the imaging display area at the driver's eye viewing position, the curved zoom unit is connected with a driving member, the driving member drives to change the position of the curved zoom unit in the optical path, so that the imaging distance can be adjusted.

2. The HUD zoom system of claim 1, wherein, The curved zoom unit is a free curved zoom unit, comprising a free curved mirror, and a wave plate is arranged on one side of the polarizing beamsplitter.

3. The HUD zoom system of claim 2, wherein, The wave plate is made of a thin film material and is vapor deposited on the reflecting surface of the free curved mirror by a coating process.

4. The HUD zoom system of claim 2, wherein, The free curved mirror is connected with a driving member, and the driving member drives the free curved mirror to axially shift along the direction parallel to the propagation direction of the light rays.

5. The HUD zoom system of claim 3, wherein, When the free curved mirror is in a first optical path position, a second optical path position or a third optical path position in the optical path, the imaging display area displays an enlarged image at a first imaging position, a second imaging position or a third imaging position, and the first imaging position, the second imaging position and the third imaging position correspond to the first optical path position, the second optical path position and the third optical path position respectively.

6. The HUD zoom system of any of claims 2 to 5, wherein, The light rays are emitted from the imaging unit, enter the wave plate as polarizing state P light after passing through the polarizing beamsplitter, enter the free curved mirror after passing through the 1 / 4 wave plate, the light rays pass through the 1 / 4 wave plate again after being reflected by the free curved mirror, the polarizing state of the light rays changes to S light, the light rays enter the windshield, are reflected by the windshield, and an enlarged image is displayed on the imaging display area.

7. The HUD zoom system of claim 6, wherein, The imaging unit is any one of a DLP, a LOCS, an LCD or a laser scanning LBS projection module.

8. The HUD zoom system of claim 7, wherein, The imaging unit uses a polarizing and polarizing device to polarize the polarized light passing through the imaging unit to P polarization state.

9. The HUD zoom system of claim 8, wherein, The polarizing and polarizing device is a 1 / 2 wave plate.

10. The HUD zoom system of claim 9, wherein, The range of the imaging display area is 3m-20m.

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