Head-up display

Abstract

The invention relates to a head-up display. The head-up display comprises an image source and an image adjusting device. The image adjusting device comprises a first reflecting mirror and a second reflecting mirror, and the first reflecting mirror is arranged in a turnover mode around the axis of the first reflecting mirror so that the first reflecting mirror can have a first posture and a second posture. The second reflecting mirror is arranged in a translation manner relative to the image source, so that the second reflecting mirror has a first position and a second position; the first reflecting mirror in the first posture and the second reflecting mirror in the first position are used for reflecting image light to a projection medium so as to form a first virtual image of a first imaging distance; the first reflecting mirror in the second posture and the second reflecting mirror in the second position are used for reflecting the image light to the projection medium so as to form a second virtual image of a second imaging distance; wherein the first virtual image and the second virtual image coincide in the direction perpendicular to the imaging distance. According to the head-up display, the imaging distance of the virtual image can be adjusted, and the position of the virtual image in the direction perpendicular to the imaging distance is not affected.

Description

Technical Field

[0001] The present disclosure relates to the technical field of head-up display, and in particular, to a head-up display. Background Art

[0002] A head-up display (HUD), also known as a head-up display system, abbreviated as HUD, is currently widely used in automobiles. The basic principle of an in-vehicle head-up display is to project important driving information such as vehicle conditions and navigation onto a projection medium such as a windshield or a specially designed screen inside the vehicle through a designed optical path, so that the light rays reflected by the image on the projection medium enter a preset eyebox, forming a virtual image that can be observed within the eyebox range to assist driving.

[0003] A head-up display, especially an augmented reality head-up display, has a need to display virtual images at different imaging distances. For example, when the vehicle is driving at high speed, it is desired that the displayed image is farther from the human eye. When the vehicle is driving slowly or in a traffic jam, it is desired that the displayed image is closer to the human eye.

[0004] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present disclosure, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0005] The purpose of the present disclosure is to provide a head-up display that can adjust the imaging distance of a virtual image and does not affect the position of the virtual image in the direction perpendicular to the imaging distance.

[0006] The present disclosure provides a head-up display, including:

[0007] An image source for emitting image light rays;

[0008] An image adjustment device for turning the image light rays to a projection medium, and the projection medium is used to reflect the image light rays into the eyebox; the image adjustment device includes a first reflector and a second reflector. The first reflector is rotatably arranged around its own axis so that the first reflector has a first posture and a second posture; the second reflector is translatably arranged relative to the image source so that the second reflector has a first position and a second position;

[0009] The first reflector in the first posture and the second reflector in the first position are used to reflect the image light rays to the projection medium to form a first virtual image with a first imaging distance; the first reflector in the second posture and the second reflector in the second position are used to reflect the image light rays to the projection medium to form a second virtual image with a second imaging distance;

[0010] Wherein, the first virtual image and the second virtual image coincide in position in the direction perpendicular to the imaging distance.

[0011] In an exemplary embodiment of the present disclosure, the included angle between the translation direction of the second mirror and the normal line of the second mirror is not greater than 45°.

[0012] In an exemplary embodiment of the present disclosure, the second mirror and the first mirror are arranged in sequence along the light-emitting direction of the image light.

[0013] In an exemplary embodiment of the present disclosure, the image adjustment device includes a third mirror. The first mirror, the second mirror, and the third mirror are arranged in sequence along the light-emitting direction of the image light, and the third mirror is a concave mirror.

[0014] In an exemplary embodiment of the present disclosure, the third mirror is rotatably arranged around its own axis so that the first virtual image or the second virtual image moves in a direction perpendicular to the imaging distance.

[0015] In an exemplary embodiment of the present disclosure, the image source includes a near-view projection module for emitting near-view image light and a far-view projection module for emitting far-view image light. The near-view image light is used to enter the projection medium through the image adjustment device to form a near-view virtual image; the far-view image light is used to enter the projection medium through the image adjustment device to form a far-view virtual image.

[0016] In an exemplary embodiment of the present disclosure, the second mirror and the first mirror are arranged in sequence along the light-emitting direction of the image light. The second mirror is used to reflect the near-view image light and the far-view image light. The near-view projection module and the first mirror are arranged on the same side of the second mirror, and the far-view projection module and the first mirror are arranged on the same side of the second mirror.

[0017] In an exemplary embodiment of the present disclosure, the second mirror is used to transmit the near-view image light and reflect the far-view image light. The near-view projection module and the first mirror are arranged on different sides of the second mirror, and the far-view projection module and the first mirror are arranged on the same side of the second mirror.

[0018] In an exemplary embodiment of the present disclosure, the image adjustment device includes a third mirror. The first mirror, the second mirror, and the third mirror are arranged in sequence along the light-emitting direction of the image light, and the third mirror is a concave mirror; wherein, the near-view image light passing through the second mirror and entering the third mirror is coaxial with the far-view image light entering the third mirror after being reflected by the first mirror and the second mirror in sequence.

[0019] In an exemplary embodiment of the present disclosure, the second mirror and the first mirror are arranged in sequence along the light-emitting direction of the image light;

[0020] Among them, the close-range projection module is configured to emit first close-range image light rays to the first mirror in the first posture; the close-range projection module is configured to emit second close-range image light rays to the first mirror in the second posture. The emission angles of the first close-range image light rays and the second close-range image light rays are different, and the first close-range image light rays and the second close-range image light rays are coaxial after being reflected by the first mirror.

[0021] In an exemplary embodiment of the present disclosure, the posture of the first mirror continuously changes between the first posture and the second posture, and the position of the second mirror continuously changes between the first position and the second position to form a virtual image with an imaging distance continuously changing between the first imaging distance and the second imaging distance.

[0022] In an exemplary embodiment of the present disclosure, the head-up display further includes a sensing module and a control unit. The sensing module is communicatively connected to the control unit. The sensing module is configured to obtain the position of an environmental object, and the control unit is configured to adjust the posture of the first mirror and the position of the second mirror according to the distance between the environmental object and the head-up display.

[0023] The head-up display of the present disclosure can adjust the imaging distance by translating the second mirror to change the position of the second mirror; at the same time, by rotating the first mirror to change the posture of the first mirror, the position change of the virtual image in the direction perpendicular to the imaging distance can be compensated, for example, the position height change of the virtual image in the direction of the vertical field of view can be compensated. Therefore, the first virtual image and the second virtual image are displayed at the same position in the human eye's field of view during display, only the imaging distances are not equal. During the process of changing the imaging distance, the driver does not need to turn the head or change the line of sight direction, so the display effect of the head-up display can be optimized. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure. Obviously, the accompanying drawings in the following description are only some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] To better understand the present disclosure, reference can be made to the embodiments shown in the following drawings. The components in the drawings are not necessarily to scale, and related elements may be omitted to emphasize and clearly illustrate the technical features of the present disclosure. In addition, related elements or components may have different arrangements as known in the art. Moreover, in the drawings, the same reference numerals represent the same or similar components in each drawing. Among them:

[0026] Figure 1Optical path schematic diagram of an exemplary embodiment of the head-up display of the present disclosure;

[0027] Figure 2 Schematic diagram of an image adjustment device in an exemplary embodiment of the head-up display of the present disclosure;

[0028] Figure 3 Schematic diagram of a method for determining the correspondence between L2, Lm, and α by ray tracing in an exemplary embodiment of the head-up display of the present disclosure;

[0029] Figure 4 Schematic diagram of an image adjustment device in another exemplary embodiment of the head-up display of the present disclosure;

[0030] Figure 5 Schematic diagram of a near-view projection module and a far-view projection module in an exemplary embodiment of the head-up display of the present disclosure;

[0031] Figure 6 Schematic diagram of a near-view projection module and a far-view projection module in another exemplary embodiment of the head-up display of the present disclosure;

[0032] Figure 7 Schematic diagram of a near-view projection module and a far-view projection module in yet another exemplary embodiment of the head-up display of the present disclosure.

[0033] Explanation of reference numerals is as follows:

[0034] 1, eye box; 2, windshield; 3, second virtual image; 31, first near-view virtual image; 32, first far-view virtual image; 4, first virtual image; 41, second near-view virtual image; 42, second far-view virtual image; 5, first reflector; 51, first reflector in the first posture; 52, first reflector in the second posture; 6, second reflector; 61, second reflector in the first position; 62, second reflector in the second position; 7, image source; 71, near-view projection module; 72, far-view projection module; 8, third reflector; 9, synthesis mirror. Detailed implementation manners

[0035] Next, the technical solutions in the exemplary embodiments of the present disclosure will be clearly and completely described in conjunction with the accompanying drawings in the exemplary embodiments of the present disclosure. The exemplary embodiments described herein are only for the purpose of illustration and are not intended to limit the protection scope of the present disclosure. Therefore, it should be understood that various modifications and changes can be made to the exemplary embodiments without departing from the protection scope of the present disclosure.

[0036] Unless otherwise specified or stated, the technical terms or scientific terms used in this disclosure shall have the ordinary meanings understood by those of ordinary skill in the field to which this disclosure pertains. In this disclosure, terms such as "first" and "second" are used only as labels, without limiting the quantity, importance, or order of their objects. Words such as "comprising" or "including" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. "Communication connection" can be a wired communication connection or a wireless communication connection, can be a direct communication, or can indirectly achieve signal connection through an intermediate medium.

[0037] Furthermore, it should be understood that when it is described in the exemplary embodiments of this disclosure that an optical surface is "concave" or "convex", it is relative to the direction of the light incident on this surface. For example, if an optical surface is "concave", the distance from a point on the incident light ray to the center of this surface on the optical axis is greater than the distance from this point to the periphery of this surface.

[0038] To facilitate the description of the solution of this disclosure, a possible application scenario provided by this disclosure takes a head-up display applied to an automobile as an example. The driver is the observer, and the windshield 2 of the automobile is the projection medium that reflects image light rays to the human eye. Those skilled in the art should understand that the head-up display can also be applied to other fields such as ships and the aviation field, or other display device fields such as head-mounted display devices, and the projection medium can also be other lenses or screens that can achieve reflection, and the observer can also be someone else. The head-up display in the exemplary embodiments of this disclosure is not limited by the actual application scenario.

[0039] In addition, the "virtual images" described in this disclosure, such as the first virtual image 4, the second virtual image 3, the near-view virtual image, and the far-view virtual image, do not depend on an actual physical display screen. The image light rays at the projection image position of the head-up display, whether they are divergent light or convergent light, can all be understood as "virtual images".

[0040] Hereinafter, some terms used in this application will be explained. It should be noted that these explanations are for the convenience of those skilled in the art to understand and do not constitute a limitation on the scope of protection required by this application.

[0041] 1) Eye box

[0042] The eye box is the area where the binoculars of the driver or observer are located. In the design of the head-up display, the eye box range can be determined according to the driver's height, posture, etc. The eye box defines an effective area for an eye point. When the eye point position of the observer moves within this effective area, the observer can see the virtual image that meets the requirements. In the area outside the eye box, problems such as image distortion, incomplete display, or even non-display may occur.

[0043] 2) Imaging distance

[0044] The imaging distance of the virtual image described in the present disclosure, i.e., the virtual image distance (VID) of the head-up display, refers to the distance between the center of the eye box and the center of the virtual image generated by the head-up display. In a possible implementation, the average value of the x coordinates of at least two reference points on the virtual image in the vehicle body coordinate system can be determined, where the x coordinate is the forward or backward direction of the vehicle; the x coordinate of the center of the eye box in the vehicle body coordinate system is determined; and the absolute value of the difference between the average value and the x coordinate of the center position of the eye box in the vehicle body coordinate system is determined as the imaging distance.

[0045] 3) Field of view

[0046] The field of view is the solid angle formed by the connection line between the object contour observed by the human eye and the center of the human eye pupil. For a head-up display, the field of view refers to the solid angle formed by the edge of the virtual image formed through the optical imaging system of the head-up display and the center of the human eye pupil. The field of view includes a horizontal field of view and a vertical field of view. The horizontal field of view is also called the lateral field of view, which is the maximum visible range of the virtual image in the horizontal direction. The vertical field of view is also called the longitudinal field of view, which is the maximum visible range of the virtual image in the longitudinal direction, i.e., the vertical direction.

[0047] In the description of the exemplary embodiments of the present disclosure, the direction perpendicular to the imaging distance includes the direction of the horizontal field of view and the direction of the vertical field of view, i.e., the horizontal direction and the height direction of the virtual image.

[0048] In the prior art, there is a need to display virtual images at different imaging distances. For example, when the vehicle is traveling at a high speed, it is desired that the displayed image is farther from the human eye. When the vehicle is traveling slowly or in a traffic jam, it is desired that the displayed image is closer to the human eye.

[0049] In a related technology, an image source 7 is composed of multiple independent projection modules to display two or more virtual images with different distances in front of the driver's eye box 1. For example, a near-view virtual image with a relatively short imaging distance and a far-view virtual image with a relatively long imaging distance are simultaneously projected and different contents are respectively displayed. For example, the near-view virtual image displays information such as speed and mileage to replace the instrument, while the far-view virtual image displays richer and larger-area information such as navigation and lane reminder. However, using multiple independent projection modules requires a large space volume and high cost.

[0050] In view of the above problems, the present disclosure provides a head-up display capable of adjusting the imaging distance of a virtual image, including an image source 7 and an image adjustment device. The image source 7 is used to emit image light, and the image adjustment device is used to deflect the image light to a projection medium (such as the windshield 2), and then the projection medium reflects the image light into the eyebox 1.

[0051] Referring to Figure 1 As shown, the image adjustment device includes a first reflector 5 and a second reflector 6. The first reflector 5 is rotatably arranged about its own axis so that the first reflector 5 has a first posture and a second posture; the second reflector 6 is translatably arranged relative to the image source 7 so that the second reflector 6 has a first position and a second position. The first reflector 51 in the first posture and the second reflector 61 in the first position are used to reflect the image light to the projection medium to form a first virtual image 4 with a first imaging distance; the first reflector 52 in the second posture and the second reflector 62 in the second position are used to reflect the image light to the projection medium to form a second virtual image 3 with a second imaging distance; wherein, the first virtual image 4 and the second virtual image 3 coincide in position in the direction perpendicular to the imaging distance.

[0052] The head-up display of the present disclosure can adjust the imaging distance by translating the second reflector 6 to change the position of the second reflector 6; at the same time, by rotating the first reflector 5 to change the posture of the first reflector 5, the position change of the virtual image in the direction perpendicular to the imaging distance can be compensated, such as compensating the position height change of the virtual image in the vertical field of view angle direction. Therefore, the first virtual image 4 and the second virtual image 3 are displayed at the same position in the human eye's field of view during display, only the imaging distances are not equal. During the change of the imaging distance, the driver does not need to turn the head or change the line of sight direction, so the display effect of the head-up display can be optimized.

[0053] Specifically, the image source 7 can be either a display imaging device or a virtual or real image formed by a display imaging device. For example, the display imaging device can include a liquid crystal screen, and the backlight light source of the liquid crystal screen can include one or more of a laser, a light-emitting diode, an organic light-emitting diode, a stimulated fluorescence emitting material, and a quantum dot excitation light source; the display imaging device can also include an active light-emitting dot matrix screen composed of light-emitting dot light sources such as LEDs, MicroLEDs, OLEDs, and plasma light-emitting dots; or, the display imaging device can further include a projection imaging system based on projection technologies such as Digital Light Processing (DLP), Liquid Crystal on Silicon (LCoS), and Liquid Crystal Display (LCD), driven by light sources such as LEDs, MicroLEDs, OLEDs, lasers, and fluorescence or combinations thereof, reflected or transmitted by display panels such as Digital Micromirror Display (DMD), LCoS, and LCD, and then projected onto a projection screen through a projection lens for imaging; the display imaging device can also include a laser beam scanning (LBS) projection imaging system in which a laser beam scans and images on a screen.

[0054] For all the display imaging devices described above, the real or virtual images formed through one or more refractions or reflections can also serve as the image source 7.

[0055] The image adjustment device includes a first reflector 5 and a second reflector 6. Exemplarily, the first reflector 5 can be a curved reflector. For example, the reflecting surface of the first reflector 5 is a concave curved surface, which has a diverging effect on the image light rays, so that the virtual image can be enlarged. The first reflector 5 can include rotating shafts provided on both sides and is rotatably connected to the housing part of the head-up display. Exemplarily, the first reflector 5 is in transmission connection with the first reflector driving mechanism, so that the first reflector driving mechanism drives the first reflector 5 to flip around the axis formed by its own rotating shaft.

[0056] For example, a transmission gear is provided on the non-reflecting surface of the first reflector 5 and is in transmission connection with the first reflector driving mechanism through the transmission gear. The first reflector driving mechanism includes a driving motor and a worm, and the transmission gear meshes with the worm; by driving the worm to rotate through the driving motor, the transmission gear is driven to move on the worm, so that the first reflector 5 flips around its own axis. Or the first reflector driving mechanism can also drive the first reflector 5 to flip using other motion methods, such as driving the first reflector 5 to flip through a linear push rod motor, a gear rack transmission mechanism, etc., which will not be elaborated here.

[0057] Exemplarily, the second mirror 6 can be a plane mirror or a curved mirror. The translation of the second mirror 6 can be along the normal line of the reflecting surface of the second mirror 6. The second mirror 6 can be in transmission connection with the second mirror driving mechanism, and the second mirror driving mechanism can also include a driving motor such as a stepper motor or a linear push rod motor, etc., to drive the second mirror 6 to move. Exemplarily, the first mirror driving mechanism and the second mirror driving mechanism can be independent of each other or integrated. In an exemplary embodiment of the present disclosure, the flipping of the first mirror 5 and the translation of the second mirror 6 are synchronized, and the time for the first mirror 5 to flip from the first posture to the second posture is equal to the time for the second mirror 6 to translate from the first position to the second position.

[0058] It should be noted that regarding the "coincidence of the positions of the first virtual image 4 and the second virtual image 3" described in the present disclosure, due to the upper limit of the manufacturing process and the assembly process accuracy, the first virtual image 4 and the second virtual image 3 may not coincide without error in practice. For example, there may be slight misalignments in the horizontal field of view angle direction and the vertical field of view angle direction. As long as it is within the allowable error range of the design, it should be regarded as coincident. Thus, it can be further explained that concepts such as "vertical" and "equal" mentioned in the present disclosure are all within the allowable range of the manufacturing process accuracy. In an exemplary embodiment of the present disclosure, the translation direction of the second mirror 61 may not be along the normal line direction of the reflecting surface of the second mirror 6. For example, the included angle between the translation direction of the second mirror 61 and the normal line of the second mirror 61 is not greater than 45°, and the rotation of the first mirror 5 can still compensate for the position change of the virtual image in the direction perpendicular to the imaging distance caused by the translation of the second mirror 61.

[0059] In an exemplary embodiment of the present disclosure, the first mirror 5 has a first posture and a second posture, referring to Figure 1 the first mirror 51 in the first posture and the first mirror 52 in the second posture shown; the second mirror 6 has a first position and a second position, referring to Figure 1 the second mirror 61 in the first position and the second mirror 62 in the second position shown. The first posture of the first mirror 5 corresponds to the first position of the second mirror 6, constituting an optical path; the second posture of the first mirror 5 corresponds to the second position of the second mirror 6, constituting an optical path, and the optical paths formed by the first mirror 5 in different postures and the second mirror 6 in different positions do not coexist.

[0060] It should be noted that the first reflector 5 described in the present disclosure has a first posture and a second posture, and the second reflector 6 has a first position and a second position, which does not mean that the first reflector 5 only has the first posture and the second posture, and the second reflector 6 only has the first position and the second position. For example, the first reflector 5 may also have an Nth posture (N is a natural number greater than 2), and the second reflector 6 has a corresponding Nth position. After the image light passes through the first reflector 5 in the Nth posture and the second reflector 6 in the Nth position and is incident on the windshield 2, the formed virtual image coincides with the first virtual image 4 and the second virtual image 3 in the position perpendicular to the imaging distance direction. That is, the head-up display according to the exemplary embodiment of the present disclosure can display virtual images with unchanged position in the horizontal and vertical field of view angles at multiple positions with unequal imaging distances.

[0061] Furthermore, in an exemplary embodiment of the present disclosure, the posture of the first reflector 5 changes continuously, and the position of the second reflector 6 changes continuously to form a virtual image with a continuously variable imaging distance. For example, the first reflector 5 takes the first posture and the second posture as the two limit positions of the posture change, and the second reflector 6 takes the first position and the second position as the two limit positions of the position change. The posture of the first reflector 5 changes continuously between the first posture and the second posture, and the position of the second reflector 6 changes continuously between the first position and the second position to form a virtual image with an imaging distance changing continuously between the first imaging distance and the second imaging distance. In other exemplary embodiments, the first posture and the second posture may not be the limit positions of the first reflector 5, and the first position and the second position may not be the limit positions of the second reflector 6.

[0062] In an exemplary embodiment of the present disclosure, referring to Figure 1 as shown, the second reflector 6 and the first reflector 5 are arranged in sequence along the light emitting direction of the image light. The image light emitted by the image source 7 passes through the second reflector 6 and the first reflector 5 in sequence and is incident on the windshield 2, and then is reflected by the windshield 2 to the eye box 1.

[0063] In an exemplary embodiment of the present disclosure, when the flipping angle of the first reflector 5 changes, on the one hand, as analyzed above, it can compensate for the position change of the virtual image in the direction perpendicular to the imaging distance; on the other hand, it can also adjust the height of the virtual image formed by the head-up display to match the height, posture and driving habits of the driver.

[0064] When the flipping angle of the first reflector 5 changes and the second reflector 6 translates, the optical path length is changed, thereby realizing the adjustment of the imaging distance. Exemplarily, during the process of a head-up display according to the present disclosure changing from the first imaging distance to the second imaging distance, the corresponding relationship between the flipping of the first reflector 5 and the translation of the second reflector 6 is as follows:

[0065] Reference Figure 2 As shown, the distance between the image source 7 and the image adjustment device is expressed as the object distance La (La1 when forming the first virtual image 4, and La2 when forming the second virtual image 3), the focal length of the image adjustment device is f, the distance between the virtual image and the image adjustment device is expressed as the object distance Lb, and the distance between the eye box 1 and the image adjustment device along the principal ray direction is expressed as Le. The distance between the eye box 1 and the virtual image is the imaging distance L (the first imaging distance is expressed as L1, and the second imaging distance is expressed as L2). Then, L = Lb + Le, and at the same time, For any point A on the image source 7, the image point after being reflected by the second mirror 61 in the first position is A1. After the second mirror 6 is translated by a distance Lm to the second position, the image point of point A after being reflected by the second mirror 62 in the second position is A2. According to the law of reflection, the distance from point A1 to the first mirror 5 is equal to the object distance La1, and the distance from point A2 to the first mirror 5 is equal to the object distance La2.

[0066] Reference Figure 2 As shown, taking the second mirror 6 as a plane mirror, that is, the magnification ratio γ of the second mirror 6 = 1. According to the imaging relationship, L a2 2 = L a1 2 + 4L m 2 + 4L a1 L m cosβ, where β is the incident angle of the principal ray of the image light on the second mirror 6 when the first virtual image 4 is formed. Then, according to the formula corresponding to the object distance La and the imaging distance L mentioned above, the relationship between the imaging distance L and the moving distance Lm of the second mirror 6 can be obtained. Among them, the object distance La1 and the incident angle β of the principal ray on the second mirror 6 when the first virtual image 4 is formed are determined. Therefore, the corresponding second imaging distance L2 can be obtained according to the moving distance Lm of the second mirror 6.

[0067] The flipping angle α of the first mirror 5 is used to compensate for the change in the height of the virtual image that may be caused by the movement of the second mirror 6: Eliminating La2 according to the relationship between La2 and La1, Lm, and β mentioned above. In the formula, β and La1 are known, and the corresponding relationship between the flipping angle α of the first mirror 5 and the moving distance Lm of the second mirror 6 can be obtained.

[0068] In an exemplary embodiment of the present disclosure, the head-up display includes a control unit, and the control unit is communicatively connected to the aforementioned mirror driving mechanism (such as the first mirror driving mechanism and the second mirror driving mechanism) to control the movement of the first mirror 5 and the second mirror 6.

[0069] For example, when the control unit controls the first mirror driving mechanism to flip the first mirror 5 from the first posture by an angle α to the second posture and controls the second mirror driving mechanism to translate the second mirror 6 from the first position by a distance Lm to the second position, the movement of the first mirror 5 and the second mirror 6 can be determined according to the above expression based on the corresponding relationship between the required second imaging distance L2, α, and Lm.

[0070] For example, a corresponding relationship table between the second imaging distance L2, α, and Lm is stored in the control unit for look-up calculation during the adjustment process of the first mirror 5 and the second mirror 6.

[0071] In another exemplary embodiment of the present disclosure, the second mirror 6 is a curved mirror, that is, the magnification γ of the second mirror 6 ≠ 1, then according to the imaging relationship, L a2 2 = L a1 2 +(L m + L m γ 2 ) 2 + 2L a1 cosβL m (1 + γ 2 ), and the relational expression between La2, the second imaging distance L2, and the rotation angle α of the first mirror 5 is the same as that in the foregoing embodiment. The corresponding relationship between the second imaging distance L2, the moving distance Lm of the second mirror 6, and the flipping angle α of the first mirror 5 can be obtained:

[0072] In an exemplary embodiment of the present disclosure, the corresponding relationship between the second imaging distance L2, the moving distance Lm of the second mirror 6, and the flipping angle α of the first mirror 5 can be realized by means of ray tracing. Specifically, referring to Figure 3 as shown, the method for determining the corresponding relationship between L2, Lm, and α by ray tracing may include the following steps:

[0073] Step S310: Establish a ray tracing model and set the initial positions of the optical elements of the image adjustment device including the first mirror 5 and the second mirror 6 and the initial position of the image source 7;

[0074] Step S320: Translate the second mirror 6;

[0075] Step S330: Perform ray tracing and calculate the imaging distance L;

[0076] Step S340: Calculate the virtual image height and calculate the flipping angle α of the first mirror 5.

[0077] Repeat the above steps S320 to S340, and for the translation distance of each second reflector 6, calculate the corresponding imaging distance L and flipping angle α until the ray tracing is completed to establish the corresponding relationship between the complete L2, Lm and α.

[0078] It should be noted that in the exemplary embodiment of the present disclosure, in addition to the first reflector 5 and the second reflector 6, the image adjustment device may further include more plane mirrors, curved mirrors or other optical elements. For example, the image adjustment device includes a third reflector 8, and the second reflector 6, the first reflector 5 and the third reflector 8 are arranged in sequence along the light-emitting direction of the image light. The third reflector 8 is used to further adjust the image light. Alternatively, the image adjustment device may include a fourth reflector, and the fourth reflector is arranged on the optical path between the second reflector 6 and the first reflector 5. For the multiple optical elements of the image adjustment device, since their optical powers are determined, it does not affect the implementation of the solution of the present disclosure.

[0079] In an exemplary embodiment of the present disclosure, the first reflector 5, the second reflector 6 and the third reflector 8 are arranged in sequence along the light-emitting direction of the image light, and the third reflector 8 is a concave reflector. Refer to Figure 4 As shown, the first reflector 5 is arranged in front of the second reflector 6. By changing the flipping angle of the first reflector 5 and translating the second reflector 6, the optical path length is changed, thereby realizing the adjustment of the imaging distance. The third reflector 8 is behind the first reflector 5 and the second reflector 6 and is used to magnify the image incident thereon.

[0080] Exemplarily, the third reflector 8 is rotatably arranged about its own axis so that the first virtual image 4 or the second virtual image 3 moves in a direction perpendicular to the imaging distance. In the exemplary embodiment of the present disclosure, the change in the flipping angle of the first reflector 5 can compensate for the position change of the virtual image in the direction perpendicular to the imaging distance, while the third reflector 8 can adjust the height of the virtual image formed by the head-up display to match the height, posture and driving habits of the driver, making the angle control of the first reflector 5 and the third reflector 8 more concise and accurate.

[0081] In an exemplary embodiment of the present disclosure, the image source 7 includes a near-view projection module 71 for emitting near-view image light rays and a far-view projection module 72 for emitting far-view image light rays. The near-view image light rays are used to enter the projection medium through the image adjustment device to form a near-view virtual image; the far-view image light rays are used to enter the projection medium through the image adjustment device to form a far-view virtual image. It should be noted that in the description of the exemplary embodiment of the present disclosure, "near view" and "far view" are only used to distinguish two different projection modules, their different projected image light rays, and virtual images with different imaging distances formed. In some embodiments, the imaging distance of the far-view virtual image is greater than that of the near-view virtual image, and in other embodiments, the imaging distance of the far-view virtual image may also be equal to the imaging distance of the near-view virtual image. In some embodiments, the imaging distance of the far-view virtual image may also be less than the imaging distance of the near-view virtual image.

[0082] The near-view projection module 71 and the far-view projection module 72 independently project two different virtual images, so that three-dimensional stereoscopic display content with depth information can be realized by displaying different contents at positions with different imaging distances. Refer to Figure 5 As shown, the near-view image light rays emitted by the near-view projection module 71 can form a first near-view virtual image 31 after being reflected by the first mirror 51 in the first posture and the second mirror 61 in the first position, and the near-view image light rays can form a second near-view virtual image 41 after being reflected by the first mirror 52 in the second posture and the second mirror 62 in the second position; the far-view image light rays emitted by the far-view projection module 72 can form a first far-view virtual image 32 after being reflected by the first mirror 51 in the first posture and the second mirror 61 in the first position, and the far-view image light rays can form a second far-view virtual image 42 after being reflected by the first mirror 52 in the second posture and the second mirror 62 in the second position. The first near-view virtual image 31 and the first far-view virtual image 32 can be fused to form a first virtual image 4 with a stereoscopic effect that can be observed within the eyebox 1, and the first far-view virtual image 32 and the second far-view virtual image 42 can be fused to form a second virtual image 3 with a stereoscopic effect that can be observed within the eyebox 1. By adjusting the first mirror 52 and the second mirror 62, the first imaging distance and the second imaging distance can be adjusted, so that the distance between the stereoscopic image and the human eye is adjustable.

[0083] In an exemplary embodiment of the present disclosure, it may also be that the near-view projection module 71 is used to project a near-view virtual image containing vehicle speed and vehicle condition information, and the far-view projection module 72 is used to project a far-view virtual image containing augmented reality information, so that the near-view virtual image can intuitively meet the driver's reading needs for text-based driving information, while the far-view virtual image can present richer information with a stronger degree of integration with reality, bringing a good driving experience.

[0084] In an exemplary embodiment of the present disclosure, the near-view projection module 71 and the far-view projection module 72 can project jointly, projecting the first near-view virtual image 31 and the first far-view virtual image 32 or the second near-view virtual image 41 and the second far-view virtual image 42 simultaneously in front of the driver; or the near-view projection module 71 and the far-view projection module 72 can project non-simultaneously, projecting the first near-view virtual image 31, or the first far-view virtual image 32, or the second near-view virtual image 41, or the second far-view virtual image 42 in front of the driver.

[0085] Exemplarily, in some embodiments, referring to Figure 5 as shown, the imaging distance of the first far-view virtual image 32 is greater than that of the first near-view virtual image 31, the imaging distance of the second far-view virtual image 42 is greater than that of the second near-view virtual image 41, and the imaging distance of the first near-view virtual image 31 is greater than that of the second far-view virtual image 42. In some other embodiments, the imaging distance of the first near-view virtual image 31 may also be equal to or less than that of the second far-view virtual image 42.

[0086] In an exemplary embodiment of the present disclosure, referring to Figure 5 as shown, the image source 7 may further include a synthesis mirror 9. The synthesis mirror 9 is used to transmit the near-view image light and reflect the far-view image light, so that the imaging distances of the far-view virtual image and the near-view virtual image are different. For example, the synthesis mirror 9 may include a partially transmissive and partially reflective film, or the synthesis mirror 9 may include a polarization beam splitter element. The polarization directions of the near-view image light and the far-view image light are opposite, and the polarization beam splitter element has a selective effect on the light, so that the near-view image light can pass through while the far-view image light is reflected.

[0087] In an exemplary embodiment of the present disclosure, the second reflector 6 is used to transmit the near-view image light and reflect the far-view image light. The near-view projection module 71 and the first reflector 5 are located on different sides of the second reflector 6, and the far-view projection module 72 and the first reflector 5 are located on the same side of the second reflector 6. Referring to Figure 6 as shown, the near-view image light passes through the second reflector 6. Then, for the first near-view virtual image 31 and the second near-view virtual image 41, their imaging distances are equal and the first near-view virtual image 31 coincides with the second near-view virtual image 41; the far-view image light is reflected by the second reflector 6, so that the imaging distance of the first far-view virtual image 32 is greater than that of the second far-view virtual image 42.

[0088] In an exemplary embodiment of the present disclosure, the near-view virtual image of the head-up display can be used to present instrument text information such as vehicle speed and vehicle condition. Its imaging distance remains unchanged, which can make it easier for the driver to focus both eyes when reading and reduce visual fatigue. The far-view virtual image for displaying augmented reality information such as lane guidance, tangent guidance, and navigation has a variable imaging distance, making its degree of fusion with reality stronger. Among them, the imaging distance of the near-view virtual image and the imaging distance of the far-view virtual image may not be equal or may be equal.

[0089] In an exemplary embodiment of the present disclosure, it may also be that the second mirror 6 is used to transmit the far-view image light and reflect the near-view image light. The far-view projection module 72 and the first mirror 5 are arranged on different sides of the second mirror 6, and the near-view projection module 71 and the first mirror 5 are arranged on the same side of the second mirror 6.

[0090] In an exemplary embodiment of the present disclosure, refer to Figure 6 As shown, the first mirror 5, the second mirror 6, and the third mirror 8 are sequentially arranged along the light-emitting direction of the far-view image light for sequentially reflecting the far-view image light; the near-view image light does not pass through the first mirror 5. The first mirror 5 is used to compensate for the height change of the far-view virtual image caused by the movement of the second mirror 6 by rotation, and the third mirror 8 is used to magnify the near-view virtual image and the far-view virtual image. Further, the third mirror 8 can also adjust the height of the virtual image formed by the head-up display to match the height, posture, and driving habits of the driver without affecting the display effects of the near-view virtual image and the far-view virtual image.

[0091] In an exemplary embodiment of the present disclosure, the second mirror 6 and the first mirror 5 are sequentially arranged along the light-emitting direction of the image light; among them, the near-view projection module 71 is used to emit the first near-view image light to the first mirror 51 in the first posture; the near-view projection module 71 is used to emit the second near-view image light to the first mirror 52 in the second posture. The emission angles of the first near-view image light and the second near-view image light are different, and the first near-view image light and the second near-view image light are coaxial after being reflected by the first mirror 5. Specifically, refer to Figure 7 As shown, both the near-view image light and the far-view image light are reflected by the first mirror 5. By adjusting the position of the display content on the light-emitting surface of the near-view projection module 71, for example, offsetting the display content from point B1 shown in Figure 7 to point B2, the emission angles of the near-view image light emitted from the same object point on the light-emitting surface of the near-view projection module 71 are different, so that the near-view virtual image does not shift after passing through the first mirror 51 in the first posture and the first mirror 52 in the second posture.

[0092] In an exemplary embodiment of the present disclosure, the head-up display further includes a sensing module. The sensing module can be communicatively connected to the control unit. The sensing module is configured to obtain the position of environmental objects, and the control unit is configured to adjust the attitude of the first mirror 51 and the position of the second mirror 6 according to the distance between the environmental objects and the head-up display. For example, when the road ahead of the vehicle is clear, the head-up display can have a greater imaging distance to fit the real scene of the road in the distance ahead; when the road conditions are complex or in a traffic jam, the head-up display can have a closer imaging distance to prevent the virtual image from being projected onto an object or the vehicle in front, affecting the driver's line of sight.

[0093] In an exemplary embodiment of the present disclosure, the sensing module can also be configured to obtain the position of the eye box 1, and the control unit is further configured to rotate the first mirror 5 or the third mirror 8, or other mirrors of the image adjustment device for adjusting the height of the virtual image formed by the head-up display according to the position of the eye box 1, so that the height of the virtual image formed by the head-up display matches the height, posture and driving habits of the driver.

[0094] Those skilled in the art will readily conceive of other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. The present disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include known common knowledge or conventional technical means in the technical field not disclosed by the present disclosure. The specification and examples are only to be considered as exemplary, and the true scope and spirit of the present disclosure are pointed out by the appended claims.

[0095] It should be understood that the present disclosure is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The protection scope of the present disclosure is only limited by the appended claims.

Claims

1. A head-up display, characterized in that, The head-up display includes: an image source (7) for emitting image light; an image adjustment device for turning the image light to a projection medium, the projection medium being used for reflecting the image light into an eyebox (1); the image adjustment device includes a first mirror (5) and a second mirror (6), the first mirror (5) is rotatably arranged about its own axis so that the first mirror (5) has a first posture and a second posture; the second mirror (6) is translatably arranged relative to the image source (7) so that the second mirror (6) has a first position and a second position; the first mirror (51) in the first posture and the second mirror (61) in the first position are used for reflecting the image light to the projection medium to form a first virtual image (4) with a first imaging distance; the first mirror (52) in the second posture and the second mirror (62) in the second position are used for reflecting the image light to the projection medium to form a second virtual image (3) with a second imaging distance; wherein, the first virtual image (4) and the second virtual image (3) coincide in position in a direction perpendicular to the imaging distance.

2. The head-up display according to claim 1, wherein, The included angle between the translation direction of the second mirror (6) and the normal line of the second mirror (6) is not greater than 45°.

3. The head-up display according to claim 1, characterized in that, The second mirror (6) and the first mirror (5) are arranged in sequence along the light-emitting direction of the image light.

4. The head-up display according to claim 1, characterized in that, The image adjustment device includes a third mirror (8), the first mirror (5), the second mirror (6) and the third mirror (8) are arranged in sequence along the light-emitting direction of the image light, and the third mirror (8) is a concave mirror.

5. The head-up display according to claim 4, characterized in that, The third mirror (8) is rotatably arranged about its own axis so that the first virtual image (4) or the second virtual image (3) moves in a direction perpendicular to the imaging distance.

6. The head-up display according to claim 1, wherein The image source (7) includes a near-view projection module (71) for emitting near-view image light and a far-view projection module (72) for emitting far-view image light, the near-view image light is used to enter the projection medium through the image adjustment device to form a near-view virtual image; the far-view image light is used to enter the projection medium through the image adjustment device to form a far-view virtual image.

7. The head-up display according to claim 6, wherein, The second mirror (6) and the first mirror (5) are arranged in sequence along the light-emitting direction of the image light, the second mirror (6) is used for reflecting the near-view image light and the far-view image light, the near-view projection module (71) and the first mirror (5) are arranged on the same side of the second mirror (6), and the far-view projection module (72) and the first mirror (5) are arranged on the same side of the second mirror (6).

8. The head-up display according to claim 6, wherein, The second mirror (6) is used for transmitting the near-view image light and reflecting the far-view image light, the near-view projection module (71) and the first mirror (5) are arranged on different sides of the second mirror (6), and the far-view projection module (72) and the first mirror (5) are arranged on the same side of the second mirror (6).

9. The head-up display according to claim 8, wherein The image adjustment device includes a third reflector (8), the first reflector (5), the second reflector (6) and the third reflector (8) are arranged in sequence along the light-emitting direction of the image light, and the third reflector (8) is a concave reflector; wherein, the near-view image light that passes through the second reflector (6) and enters the third reflector (8) is coaxial with the far-view image light that enters the third reflector (8) after being reflected by the first reflector (5) and the second reflector (6) in sequence.

10. The head-up display according to claim 8, characterized in that, The second reflector (6) and the first reflector (5) are arranged in sequence along the light-emitting direction of the image light; Wherein, the near-view projection module (71) is configured to emit first near-view image light to the first reflector (51) in the first posture; the near-view projection module (71) is configured to emit second near-view image light to the first reflector (52) in the second posture, the emission angles of the first near-view image light and the second near-view image light are different, and the first near-view image light and the second near-view image light are coaxial after being reflected by the first reflector (5).

11. The head-up display according to any one of claims 1 to 10, characterized in that, The posture of the first reflector (5) continuously changes between the first posture and the second posture, and the position of the second reflector (6) continuously changes between the first position and the second position to form a virtual image with an imaging distance continuously changing between the first imaging distance and the second imaging distance.

12. The head-up display according to claim 1, characterized in that, The head-up display further includes a sensing module and a control unit, the sensing module is communicatively connected to the control unit, the sensing module is configured to obtain the position of an environmental object, and the control unit is configured to adjust the posture of the first reflector (51) and the position of the second reflector (6) according to the distance between the environmental object and the head-up display.

Images