Head-up display device

Abstract

Disclosed in the present application is a head-up display device, comprising a light source, a polarizing beam splitter, a first liquid crystal panel and a second liquid crystal panel, wherein the light source is configured to emit natural light; and the polarizing beam splitter is configured to transmit first polarized light and reflect second polarized light. First linearly-polarized light among the light emitted by the light source is transmitted to the first liquid crystal panel by means of the polarizing beam splitter, the first liquid crystal panel modulates the first linearly-polarized light, converts same into second linearly-polarized light and reflects the second linearly-polarized light to the polarizing beam splitter, and the second linearly-polarized light is projected to a windshield by means of the polarizing beam splitter at a first object distance and then forms an image at a first image distance. Second linearly-polarized light among the light emitted by the light source is reflected to the second liquid crystal panel by means of the polarizing beam splitter, the second liquid crystal panel modulates the second linearly-polarized light, converts same into the first linearly-polarized light and reflects the first linearly-polarized light to the polarizing beam splitter, and the first linearly-polarized light is projected to the windshield by the polarizing beam splitter at a second object distance and then forms an image at a second image distance, the second object distance being different from the first object distance, and the second image distance being different from the first image distance.

Description

Head-up display device

[0001] Cross-reference to related applications

[0002] The present application claims priority to the Chinese patent application No. 202410834074.9, filed on June 25, 2024, and entitled "A head-up display device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of head-up display, and in particular to a head-up display device. BACKGROUND

[0004] The AR-HUD technology, which is a combination of augmented reality (AR) technology and head-up display (HUD) technology, can project the image displayed by the picture generation units (PGU) in the HUD device to the driving road and the surrounding environment, so that the driver can obtain the required information without lowering his head.

[0005] Currently, the projection distance of AR-HUD is generally between 7.5 meters and 13 meters. If only one focal plane is used for display, it is difficult to meet the reading needs of the driver for text driving information. Therefore, it has become an important trend to image the display pictures with different information on two different focal planes. FIG. 1 is a structural schematic diagram of a double-focal-plane head-up display device in the related art. As shown in FIG. 1, the head-up display device in the related art includes two image display units, which are a first image display unit PGU1 and a second image display unit PGU2. The light emitted by the first image display unit PGU1 is emitted after being reflected by the first mirror M1. The light emitted by the second image display unit PGU2 is emitted after being reflected by the second mirror M2 and the first mirror M1 in sequence. The region of the first mirror M1, on which the light emitted by the second image display unit PGU2 is incident, is different from the region of the first mirror M1, on which the light emitted by the first image display unit PGU1 is incident. The distances from the different regions of the first mirror M1 to the windshield are different. Therefore, the display pictures of the first image display unit PGU1 and the second image display unit PGU2 can be imaged on two different focal planes after passing through the windshield G.

[0006] However, in this structure, two image display units need to be provided with backlight sources, which occupies a large space. When the image display unit uses a liquid crystal display, a polarizing plate is usually provided to improve the display effect. However, the polarizing plate will cause a loss of half of the light, resulting in a low overall light utilization rate. SUMMARY

[0007] The application provides a head-up display device to improve the utilization rate of light emitted by a light source and has a small volume.

[0008] The application provides a head-up display device, comprising a light source, a polarization beam splitter, a first liquid crystal panel and a second liquid crystal panel; the light source is used for emitting natural light; the polarization beam splitter is located on the light emitting side of the light source and is used for transmitting first polarized light and reflecting second polarized light, and the polarization directions of the first polarized light and the second polarized light are perpendicular;

[0009] The first polarized light in the light emitted by the light source is transmitted to the first liquid crystal panel by the polarization beam splitter, the first liquid crystal panel is used for modulating the first polarized light and converting it into second polarized light which is reflected to the polarization beam splitter, and the second polarized light is projected to the windshield at a first object distance by the polarization beam splitter and is imaged at a first image distance;

[0010] The second polarized light in the light emitted by the light source is reflected to the second liquid crystal panel by the polarization beam splitter, the second liquid crystal panel is used for modulating the second polarized light and converting it into first polarized light which is reflected to the polarization beam splitter, and the first polarized light is projected to the windshield at a second object distance by the polarization beam splitter and is imaged at a second image distance; the second object distance is different from the first object distance, and the second image distance is different from the first image distance.

[0011] In some embodiments of the application, the first liquid crystal panel and the second liquid crystal panel are configured such that the relative position of the first liquid crystal panel to the polarization beam splitter is adjustable to make the first object distance and the first image distance adjustable; and / or the relative position of the second liquid crystal panel to the polarization beam splitter is adjustable to make the second object distance and the second image distance adjustable.

[0012] In some embodiments of the application, the head-up display device further comprises a first sliding rail, the first sliding rail is movably connected with the first liquid crystal panel, and the first liquid crystal panel moves along the first sliding rail to change the first object distance and the first image distance.

[0013] In some embodiments of the application, the head-up display device further comprises a second sliding rail, the second sliding rail is movably connected with the second liquid crystal panel, and the second liquid crystal panel moves along the second sliding rail to change the second object distance and the second image distance.

[0014] In some embodiments of the application, the size of the second liquid crystal panel is smaller than the size of the first liquid crystal panel, and the head-up display device further comprises a third sliding rail, the third sliding rail is used for moving the second liquid crystal panel in a plane perpendicular to the extension direction of the second sliding rail.

[0015] In some embodiments of the present application, the light source, the polarization beam splitter and the first liquid crystal panel are arranged in a first direction, and the second liquid crystal panel and the polarization beam splitter are arranged in a second direction, the second direction being perpendicular to the first direction.

[0016] The interval between the first liquid crystal panel and the polarization beam splitter in the first direction is different from the interval between the second liquid crystal panel and the polarization beam splitter in the second direction.

[0017] In some embodiments of the present application, the polarization beam splitter covers the first liquid crystal panel in the first direction, and the polarization beam splitter covers the second liquid crystal panel in the second direction.

[0018] In some embodiments of the present application, the light source and the polarization beam splitter are arranged in a first direction, and the second liquid crystal panel and the polarization beam splitter are arranged in a second direction, the second direction being perpendicular to the first direction.

[0019] The head-up display device further comprises a first mirror, the first mirror being located on the light path between the polarization beam splitter and the first liquid crystal panel, and the first mirror being arranged at a set angle with the first direction.

[0020] In some embodiments of the present application, the first liquid crystal panel and the second liquid crystal panel are spliced with each other.

[0021] In some embodiments of the present application, the head-up display device further comprises at least one second mirror, the at least one second mirror being used for reflecting the light emitted by the polarization beam splitter to the windshield.

[0022] In some embodiments of the present application, the at least one second mirror comprises a free-form mirror.

[0023] In some embodiments of the present application, the at least one second mirror further comprises a plane mirror, the plane mirror being located on the light path between the polarization beam splitter and the free-form mirror, and being used for reflecting the light emitted by the polarization beam splitter to the free-form mirror.

[0024] The present application has the following advantages:

[0025] The head-up display provided in the application comprises a light source, a polarization beam splitter, a first liquid crystal panel and a second liquid crystal panel; wherein the light source is used for emitting natural light; the polarization beam splitter is located on the light emitting side of the light source and is used for transmitting first polarized light and reflecting second polarized light, and the polarization directions of the first linear polarized light and the second linear polarized light are perpendicular; the first linear polarized light in the light emitted by the light source is transmitted to the first liquid crystal panel by the polarization beam splitter, the first liquid crystal panel is used for modulating the first linear polarized light and converting it into second linear polarized light which is reflected to the polarization beam splitter, and the second linear polarized light is projected to the windshield at a first object distance by the polarization beam splitter and is imaged at a first image distance after the windshield; the second linear polarized light in the light emitted by the light source is reflected to the second liquid crystal panel by the polarization beam splitter, the second liquid crystal panel is used for modulating the second linear polarized light and converting it into first linear polarized light which is reflected to the polarization beam splitter, and the first linear polarized light is projected to the windshield at a second object distance by the polarization beam splitter and is imaged at a second image distance after the windshield; the second object distance is different from the first object distance, and the second image distance is different from the first image distance. The application sets a single light source to provide backlight for two liquid crystal panels to form a display picture, and sets the polarization beam splitter to use the light rays of different polarization states emitted by the light source to image the display picture on two focus planes with different distances, which is beneficial to improve the utilization rate of light rays and reduce the volume of the device. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments of the application. Obviously, the drawings introduced below are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0027] FIG. 1 is a structural schematic diagram of a double-focus head-up display device in the related art;

[0028] FIG. 2 is a schematic diagram of an application scenario of a head-up display device provided in an embodiment of the application;

[0029] FIG. 3 is a structural schematic diagram of a head-up display device provided in an embodiment of the application;

[0030] FIG. 4 is a light path schematic diagram of second linear polarized light emitted by a first liquid crystal panel provided in an embodiment of the application;

[0031] FIG. 5 is a light path schematic diagram of first linear polarized light emitted by a second liquid crystal panel provided in an embodiment of the application;

[0032] FIG. 6 is a field of view angle schematic diagram of first imaging and second imaging provided in an embodiment of the application;

[0033] FIG. 7 is a structural schematic diagram of another head-up display device provided in an embodiment of the application;

[0034] FIG. 8 is a structural schematic diagram of another head-up display device according to an embodiment of the present application;

[0035] FIG. 9 is a structural schematic diagram of another head-up display device according to an embodiment of the present application;

[0036] FIG. 10 is a structural schematic diagram of another head-up display device according to an embodiment of the present application;

[0037] FIG. 11 is a structural schematic diagram of another head-up display device according to an embodiment of the present application;

[0038] FIG. 12 is a structural schematic diagram of another head-up display device according to an embodiment of the present application;

[0039] FIG. 13 is a structural schematic diagram of another head-up display device according to an embodiment of the present application.

[0040] Legend: PGU1-first image display unit, PGU2-second image display unit, M1-first mirror, M2-second mirror, G-windshield, 100-head-up display device, 1-light source, 2-polarizing beam splitter, 31-first liquid crystal panel, 32-second liquid crystal panel, 4-reflecting cup, 5-Fresnel lens, 61-first sliding rail, 62-second sliding rail, 91-connector, 92-frame, D1-first direction, D2-second direction, 7-first reflecting mirror, 81-flat reflecting mirror, 82-free-form reflecting mirror, S1'-first imaging, S2'-second imaging. DETAILED DESCRIPTION

[0041] In order to make the above objectives, features and advantages of the present application more apparent, further description will be made to the present application with reference to the accompanying drawings and embodiments. However, the example embodiments can be implemented in various forms, and should not be understood as being limited to the embodiments set forth herein; on the contrary, these embodiments are provided to make the present application more comprehensive and complete, and to fully convey the ideas of the example embodiments to those skilled in the art. The same reference signs in the drawings represent the same or similar structures, and thus repeated description thereof will be omitted. The words expressing position and direction described in the present application are explained with reference to the drawings, but can be changed as needed, and the changes made are included in the protection scope of the present application. The drawings of the present application are only used to show the relative position relationship and do not represent the real proportions.

[0042] FIG. 2 is a schematic diagram of an application scenario of a head-up display device according to an embodiment of the present application.

[0043] As shown in FIG. 2, the head-up display device provided by the embodiments of the present application can be used as a vehicle-mounted head-up display device, for example, installed in the space below the instrument panel. The light emitted by the head-up display device 100 is projected on the windshield G and reflected by the windshield G to the human eye, so that the human eye can observe the virtual image of the display screen of the head-up display device in front of the windshield G.

[0044] FIG. 3 is a structural schematic diagram of a head-up display device provided by the embodiments of the present application.

[0045] As shown in FIG. 3, in the embodiments of the present application, the head-up display device comprises a light source 1, a polarization beam splitter 2, a first liquid crystal panel 31 and a second liquid crystal panel 32.

[0046] The light source 1 is used to emit natural light to provide backlight for the first liquid crystal panel 31 and the second liquid crystal panel 32. The type of the light source 1 is selected according to specific requirements. For example, a high-power integrated surface light source 1 using chip on board (COB) technology can be used to integrate multiple light emitting elements on the same substrate, so that the display screen can have higher brightness and contrast. The light emitting side of the light source 1 can also be provided with a light cup 4 and a Fresnel lens 5 and other devices to collimate the light emitted thereby, so as to improve the imaging quality of the display screen.

[0047] The polarization beam splitter 2 can use, but is not limited to, a polarization beam splitter (PBS) or a composite polarization film material such as DLRP, so that the polarization beam splitter 2 can be used to transmit first linearly polarized light and reflect second linearly polarized light, wherein the polarization directions of the first linearly polarized light and the second linearly polarized light are perpendicular. Taking the case where the polarization beam splitter 2 uses a PBS prism as an example, the first linearly polarized light can be S light, and the second linearly polarized light can be P light. It can be understood that by designing the polarization film material in the polarization beam splitter 2, it is also possible to realize that the polarization beam splitter 2 transmits P light and reflects S light. For the sake of description, the case where the polarization beam splitter 2 uses a PBS prism is taken as an example for description in the following embodiments.

[0048] The polarization beam splitter 2 is located on the light exit side of the light source 1, and the first liquid crystal panel 31 and the second liquid crystal panel 32 can be respectively located near two light exit surfaces of the polarization beam splitter 2 and arranged in parallel with the light splitting surface of the polarization beam splitter 2, or a mirror or other device can be arranged to change the light propagation path, so that the first liquid crystal panel 31 and the second liquid crystal panel 32 can be arranged at any convenient position in the device. The relative positions of the light source 1, the first liquid crystal panel 31, the second liquid crystal panel 32, and the polarization beam splitter 2 should be such that the first linearly polarized light in the light emitted by the light source 1 can be transmitted by the polarization beam splitter 2 to the first liquid crystal panel 31, and the second linearly polarized light in the light emitted by the light source 1 can be reflected by the polarization beam splitter 2 to the second liquid crystal panel 32.

[0049] The liquid crystal panel can modulate the light incident therein, for example, by applying an electric field to control the deflection state of the liquid crystal molecules in the liquid crystal panel, the transmittance and reflectivity of the incident light can be adjusted, so as to change the brightness, contrast and color of the display picture. The display picture can be a black and white picture, or a color picture can be displayed by arranging a color film (CF) in the liquid crystal panel.

[0050] The first linearly polarized light is incident to the first liquid crystal panel 31, and forms a first display picture after being modulated by the first liquid crystal panel 31, and the first liquid crystal panel 31 converts the first linearly polarized light into second linearly polarized light and reflects it to the polarization beam splitter 2. Specifically, the deflection state of the liquid crystal molecules in the first liquid crystal panel 31 can be controlled, or a quarter-wave plate or other device can be arranged between the polarization beam splitter 2 and the first liquid crystal panel 31 to convert the first linearly polarized light incident to the first liquid crystal panel 31 into second linearly polarized light. The first liquid crystal panel 31 is a reflective liquid crystal panel, and a reflective layer is arranged on the back of the first liquid crystal panel 31, i.e. on the side facing away from the polarization beam splitter 2, so as to reflect the light modulated by the first liquid crystal panel 31 to the polarization beam splitter 2. Similarly, the second linearly polarized light is incident to the second liquid crystal panel 32, and forms a second display picture after being modulated by the second liquid crystal panel 32, and the second liquid crystal panel 32 converts the second linearly polarized light into first linearly polarized light and reflects it to the polarization beam splitter 2.

[0051] As can be seen, the present application only provides a single light source 1, and the polarization beam splitter 2 transmits two parts of light with different polarization states to the first liquid crystal panel 31 and the second liquid crystal panel 32 to form a display picture, so that the light emitted by the light source 1 can be fully utilized, the light utilization rate is improved by one time compared with related art, the heat generated by light loss is greatly reduced, which is conducive to improving the reliability of the device, and the number of internal devices of the device is less, the structure is simpler, which is conducive to saving cost and realizing product miniaturization.

[0052] The second linearly polarized light emitted by the first liquid crystal panel 31 can be reflected by the polarization beam splitter 2, and the first linearly polarized light emitted by the second liquid crystal panel 32 can be transmitted by the polarization beam splitter 2. The first linearly polarized light and the second linearly polarized light are emitted from the same side of the polarization beam splitter 2 to other optical devices in the device, and finally imaged to the front of the driver's line of sight by the windshield G, wherein the second linearly polarized light is projected to the windshield G through the polarization beam splitter 2 with a first object distance and imaged with a first image distance after the windshield G, and the first linearly polarized light is projected to the windshield G through the polarization beam splitter 2 with a second object distance and imaged with a second image distance after the windshield G.

[0053] The first object distance is the length of the propagation path of the second linearly polarized light from the first liquid crystal panel 31 to the windshield G, and the second object distance is the length of the propagation path of the first linearly polarized light from the second liquid crystal panel 32 to the windshield G. Since the propagation paths of the first linearly polarized light and the second linearly polarized light after being emitted from the polarization beam splitter 2 are consistent, and the lengths of the propagation paths in the polarization beam splitter 2 are the same, the first object distance and the second object distance are the same or different. The relative positions of the polarization beam splitter 2, the first liquid crystal panel 31 and the second liquid crystal panel 32 determine whether the first object distance and the second object distance are the same or different, and the first image distance and the second image distance are different according to the imaging principle.

[0054] In the embodiments of the present application, the first object distance is greater than the second object distance, and the first image distance is greater than the second image distance. The first object distance can be changed by adjusting the relative position of the first liquid crystal panel 31 and the polarization beam splitter 2, and then adjusting the first image distance. The second object distance can be changed by adjusting the relative position of the second liquid crystal panel 32 and the polarization beam splitter 2, and then adjusting the second image distance. The first liquid crystal panel 31 and the second liquid crystal panel 32 can be fixed or movable. For example, a movable mechanical structure can be provided on the first liquid crystal panel 31 and the second liquid crystal panel 32 to drive the first liquid crystal panel 31 and the second liquid crystal panel 32 to approach or move away from the polarization beam splitter 2.

[0055] In some embodiments, the first object distance can also be less than the second object distance. The specific conditions need to be set according to the installation angle of the heads-up display device, the position of the light emitted by the first liquid crystal panel 31 and the second liquid crystal panel 32 incident to the windshield G, etc. The embodiments of the present application and the following embodiments are described by taking the case that the first object distance is greater than the second object distance as an example. The imaging principle is as follows.

[0056] FIG. 4 is a schematic diagram of a light path of the second linearly polarized light emitted by the first liquid crystal panel according to an embodiment of the present application; and FIG. 5 is a schematic diagram of a light path of the first linearly polarized light emitted by the second liquid crystal panel according to an embodiment of the present application. For the convenience of description, the display screen of the first liquid crystal panel 31 is referred to as a first display screen, the image of the first display screen formed in front of the windshield G is referred to as a first imaging, the display screen of the second liquid crystal panel 32 is referred to as a second display screen, and the image of the second display screen formed in front of the windshield G is referred to as a second imaging.

[0057] According to the following geometric optical imaging formula:

[0058] wherein L1 represents the object distance of any object point in the first display screen when the object point is imaged by the windshield G, i.e., a first object distance, H1 represents the first image distance of the imaged point of the object point by the windshield G, and f1 represents the focal length of the second linearly polarized light incident on the windshield G corresponding to the object point and the imaged point; L2 represents the object distance of any object point in the second display screen when the object point is imaged by the windshield G, i.e., a second object distance, H2 represents the second image distance of the imaged point of the object point by the windshield G, and f2 represents the focal length of the first linearly polarized light incident on the windshield G corresponding to the object point and the imaged point.

[0059] It can be seen that the first object distance and the second object distance are different, and the first image distance is different from the second image distance, i.e., the first imaging S1’ and the second imaging S2’ are located on two focal planes which are different in distance. According to the present embodiment, a single light source 1 is used in combination with a polarization beam splitter 2 and two display panels, so that double focal plane display is achieved.

[0060] For example, in the case that the first image distance is greater than the second image distance, referring to FIG. 4, the first imaging S1’ is located on a relatively far focal plane, and the first image distance can be between 5 m and 10 m. Optionally, the first image distance is 9 m. Referring to FIG. 5, the second imaging S2’ is located on a relatively near focal plane, and the second image distance can be between 1 m and 5 m. Optionally, the second image distance is 2.5 m.

[0061] FIG. 6 is a schematic diagram of the field of view of the first imaging and the second imaging according to an embodiment of the present application.

[0062] As shown in FIG. 6, the field of view of the first imaging S1’ is greater than the field of view of the second imaging S2’, i.e., the first imaging S1’ has a larger screen than the second imaging S2’. For example, the field of view of the first imaging S1’ is 2°x1° to 13°x7°, and optionally, the field of view of the first imaging S1’ is 10°x5°. The field of view of the second imaging S2’ is 2°x1° to 7°x5°, and optionally, the field of view of the second imaging S2’ is 6°x2°.

[0063] The difference of the field of view angle of the first imaging S1' and the second imaging S2' in the vertical direction can range from 0° to 5°, and optionally, the difference is 1°, and the difference should be at least greater than 0°, so as to avoid the first imaging S1' and the second imaging S2' overlapping in the vertical direction and affecting the driver's line of sight.

[0064] In actual applications, the farther first imaging S1' is suitable for displaying information interacting with the driving road and the surrounding environment, for example, the first imaging S1' can be used to display information including but not limited to warning information for issuing an alarm when the vehicle is close to the surrounding objects, and prompt information for prompting the distance from the front object, lane change, traffic light, etc.; the closer second imaging S2' is suitable for displaying information on the instrument panel, for example, the second imaging S2' can be used to display information including but not limited to speed, mileage, navigation information, and entertainment, call, music, etc.

[0065] FIG. 7 is a structural schematic diagram of another head-up display device provided by the embodiments of the present application.

[0066] As shown in FIG. 7, the head-up display device can further include a first sliding rail 61, the first sliding rail 61 is movably connected with the first liquid crystal panel 31, and the first liquid crystal panel 31 moves along the first sliding rail 61 to change the distance between the polarizing beam splitter 2 and the first liquid crystal panel 31, that is, to change the first object distance when the first display picture is imaged with respect to the windshield G, so that the first image distance is correspondingly changed.

[0067] Similarly, the head-up display device can further include a second sliding rail 62, the second sliding rail 62 is movably connected with the second liquid crystal panel 32, and the second liquid crystal panel 32 moves along the second sliding rail 62 to change the distance between the polarizing beam splitter 2 and the second liquid crystal panel 32, that is, to change the second object distance when the second display picture is imaged with respect to the windshield G, so that the second image distance is correspondingly changed.

[0068] In the embodiments of the present application, by adjusting the position of the liquid crystal panel on the sliding rail, the position of the display picture imaging can be changed, and the size and distance of the imaging picture can be adjusted, so as to meet the personalized needs and make the display picture image at a comfortable position for the driver to watch. In actual applications, the position of the liquid crystal panel on the sliding rail can be preset before driving, and the liquid crystal panel can also be controlled to move on the corresponding sliding rail during driving, for example, by setting an eye tracking device or a voice control, so as to flexibly adjust the imaging position according to the actual situation.

[0069] For example, the first liquid crystal panel 31 can be moved on the first slide rail 61 by a distance of 0 m-500 mm, and the second liquid crystal panel 32 can be moved on the second slide rail 62 by a distance of 0 mm-20 mm. Optionally, the first liquid crystal panel 31 can be moved on the first slide rail 61 to a distance of 275 mm from the polarizing beam splitter 2, and the second liquid crystal panel 32 can be moved on the second slide rail 62 to a distance of 10 mm from the polarizing beam splitter 2.

[0070] As shown in FIG. 7, the liquid crystal panel and the slide rail are connected by a connector 91 such as a nut, and the corresponding liquid crystal panel is moved by a driving mode such as a motor. A frame 92 can be provided around the liquid crystal panel and the polarizing beam splitter 2 to connect the connector 91 and allow the liquid crystal panel to move farther or closer to the polarizing beam splitter 2.

[0071] In specific implementations, only the first slide rail 61 can be provided, or only the second slide rail 62 can be provided, or both can be provided. The connector 91 can be provided on each slide rail to connect the corresponding liquid crystal panel, or the connector 91 can be provided on only part of the slide rail to connect the corresponding liquid crystal panel. The specific shape of the frame 92 around the liquid crystal panel and the polarizing beam splitter 2 can be designed according to the specific needs of the product, and is not limited herein.

[0072] Since the size of the second display image is usually smaller than that of the first display image, in some embodiments of the present application, the size of the second liquid crystal panel 32 can be set to be smaller than that of the first liquid crystal panel 31. In this case, a third slide rail can be further included in the head-up display device, and the second liquid crystal panel 32 is movably connected to the third slide rail through the connector 91, so that the second liquid crystal panel 32 moves in a plane perpendicular to the extension direction of the second slide rail 62. The movement of the second liquid crystal panel 32 on the third slide rail does not change the object distance of the second display image when the second display image is imaged with respect to the windshield G, i.e., does not change the distance of the second imaging S2', but changes the position of the second imaging S2' in the focal plane where the second imaging S2' is located.

[0073] For example, referring to FIG. 6, the second imaging S2' can move in the horizontal direction, and the distance of movement satisfies l1+l2+l3=L, where l1 and l2 respectively represent the distance of movement of the second imaging S2' to the left and right in the horizontal direction, l3 represents the width of the second imaging S2' in the horizontal direction, and L represents the width of the first imaging S1' in the horizontal direction. Thus, the second imaging S2' does not exceed the range of the first imaging S1' in the horizontal direction, avoiding the loss of information caused by the incomplete picture of the second imaging S2' observed by the driver.

[0074] In some embodiments of the present application, the size of the first liquid crystal panel 31 and the second liquid crystal panel 32 can be different, and the size of the first liquid crystal panel 31 can be larger than that of the second liquid crystal panel 32. In this case, the first display image can be displayed in the display area of the first liquid crystal panel 31, and the second display image can be displayed in the display area of the second liquid crystal panel 32. The display image can be moved in the display area of the second liquid crystal panel 32 by controlling the display image in the display area of the second liquid crystal panel 32, so as to realize the movement of the second imaging S2' in the focal plane where the second imaging S2' is located.

[0075] The size and relative position of each device in the head-up display device, including angle and spacing, need to be designed according to the application scene and product demand, so as to make the head-up display device have higher light output efficiency and better stability. For example, in the embodiments shown in FIG. 3 and FIG. 7, the light source 1, the polarization beam splitter 2 and the first liquid crystal panel 31 are arranged in sequence along the first direction D1, the second liquid crystal panel 32 and the polarization beam splitter 2 are arranged along the second direction D2, the second direction D2 is perpendicular to the first direction D1, the first sliding rail 61 extends along the first direction D1, and the second sliding rail 62 extends along the second direction D2. By controlling the distance between the first liquid crystal panel 31 and the polarization beam splitter 2 in the first direction D1 and the distance between the second liquid crystal panel 32 and the polarization beam splitter 2 in the second direction D2, the object distance of the first display image and the second display image when the first display image and the second display image are imaged with respect to the windshield G can be different.

[0076] The size of the polarization beam splitter 2 should be larger than the size of the first liquid crystal panel 31 and the second liquid crystal panel 32, that is, the orthographic projection of the polarization beam splitter 2 in the first direction D1 covers the orthographic projection of the first liquid crystal panel 31 in the first direction D1, and the orthographic projection of the polarization beam splitter 2 in the second direction D2 covers the orthographic projection of the second liquid crystal panel 32 in the second direction D2. In this way, the light reflected by the first liquid crystal panel 31 and the second liquid crystal panel 32 can be incident to the polarization beam splitter 2 as much as possible, so as to ensure that the first display image and the second display image can be completely imaged, avoid information loss, and improve the light output efficiency of the head-up display device.

[0077] For example, the light emitting area of the light source 1 has a size of 6.5mm*5.0mm to 11.8mm*7.9mm, or a size of 10.6mm*6.9mm, the light emitting surface of the light source 1 has an angle of 0°-60° with the first direction D1, or an angle of 17° with the first direction D1; the distance between the light source 1 and the light inlet of the reflector cup 4 is 0mm-5mm, the light inlet of the reflector cup 4 has a size of 10.6mm*6.9mm to 21.2mm*13.8mm, or a size of 12.6mm*8.9mm; the angle between the light emitting surface of the reflector cup 4 and the first direction D1 is consistent with the angle between the light emitting surface of the light source 1 and the first direction D1, for example, 17°; the light outlet of the reflector cup 4 has a size larger than the size of the first liquid crystal panel 31 and the second liquid crystal panel 32, for example, the size of the liquid crystal panel is 1.0inch-5.0inch, or 2inch, and the size of the light outlet of the reflector cup 4 is 2.0inch-3.0inch, or 2.2inch; the distance between the light outlet of the reflector cup 4 and the Fresnel lens 5 is 0mm-8mm, or 2mm, and the size of the Fresnel lens 5 is consistent with the size of the light outlet of the reflector cup 4; the angle between the Fresnel lens 5 and the polarizing beam splitter 2 is 0°, and the distance between the Fresnel lens 5 and the polarizing beam splitter 2 is 0mm-20mm, or 2mm.

[0078] FIG. 8 is a structural schematic diagram of another head-up display device provided by the embodiments of the present application.

[0079] As shown in FIG. 8, in the embodiments of the present application, the light source 1 and the polarizing beam splitter 2 are arranged along the first direction D1, the second liquid crystal panel 32 and the polarizing beam splitter 2 are arranged along the second direction D2, and the head-up display device further comprises a first reflector 7, which is located on the light path between the polarizing beam splitter 2 and the first liquid crystal panel 31, and is arranged at a set angle with the first direction D1, and the first reflector 7 is used for reflecting the first polarized light transmitted by the polarizing beam splitter 2 to the first liquid crystal panel 31, and reflecting the second polarized light reflected by the first liquid crystal panel 31 to the polarizing beam splitter 2. By arranging the first reflector 7, the light path between the polarizing beam splitter 2 and the first liquid crystal panel 31 can be folded, so that the first object distance is increased in the same length of the first direction D1, which is conducive to reducing the volume of the head-up display device and meeting the design requirement of miniaturization.

[0080] FIG. 9 is a structural schematic diagram of another head-up display device according to an embodiment of the present application; and FIG. 10 is a structural schematic diagram of another head-up display device according to an embodiment of the present application.

[0081] As shown in FIG. 9 and FIG. 10, in the embodiments of the present application, the first liquid crystal panel 31 and the second liquid crystal panel 32 can be arranged on the same side of the polarization beam splitter 2, and the first mirror 7 is arranged between the polarization beam splitter 2 and the first liquid crystal panel 31, and the first mirror 7 is arranged at a certain angle with the first direction D1, so that the first mirror 7 can guide the light emitted by the polarization beam splitter 2 to the first liquid crystal panel 31. As shown in FIG. 9, the first liquid crystal panel 31 and the second liquid crystal panel 32 can be arranged at intervals, or as shown in FIG. 10, the first liquid crystal panel 31 and the second liquid crystal panel 32 can be spliced with each other, thereby further reducing the number of devices in the device and facilitating the reduction of assembly difficulty.

[0082] It can be understood that for the head-up display devices shown in FIG. 9 and FIG. 10, the first liquid crystal panel 31 and the second liquid crystal panel 32 can also be provided with sliding rails to change the image distance of imaging. The arrangement of the sliding rails can refer to the description in the embodiment shown in FIG. 7, which will not be repeated here. For the structure shown in FIG. 10, the arrangement of the sliding rails can simultaneously move the spliced display screen, that is, simultaneously adjust the distance of the first imaging S1' and the second imaging S2', and the number of devices in the device is further reduced, which is conducive to reducing the size of the device.

[0083] As shown in FIG. 3, FIG. 7, FIG. 9 and FIG. 10, the head-up display device can further include at least one second mirror, which is located on the light path between the polarization beam splitter 2 and the windshield G, and is used to reflect the light emitted by the polarization beam splitter 2 to the windshield G. The at least one second mirror includes a plane mirror 81 and a free-form surface mirror 82. The plane mirror 81 is located on the light path between the polarization beam splitter 2 and the free-form surface mirror 82, and is used to reflect the light emitted by the polarization beam splitter 2 to the free-form surface mirror 82. Thus, the optical path of the light between the polarization beam splitter 2 and the windshield G can be increased in a smaller space, thereby further reducing the size of the head-up display device to meet the design requirement of miniaturization. In addition, the free-form surface mirror 82 also has the function of adjusting aberration, which is conducive to improving the imaging quality.

[0084] The inclination angle of each second mirror and the distance between the second mirror and other devices can be designed according to specific requirements. For example, the inclination angle of the plane mirror 81 is 20°-70°, and optionally, the inclination angle of the plane mirror 81 is 37°. The inclination angle of the free-form surface mirror 82 is 0°-90°, and optionally, the inclination angle of the free-form surface mirror is 28°.

[0085] FIG. 11 is a structural schematic diagram of another head-up display device according to an embodiment of the present application; FIG. 12 is a structural schematic diagram of another head-up display device according to an embodiment of the present application; and FIG. 13 is a structural schematic diagram of another head-up display device according to an embodiment of the present application.

[0086] As shown in FIGS. 8 and 11-13, for each of the above embodiments, only one free-form mirror 82 can be arranged between the light path between the polarization beam splitter 2 and the windshield G. This design is suitable for products with a short imaging distance requirement, and the number of devices in the device is less, which can reduce the assembly difficulty of the head-up display device and reduce the volume, and meanwhile improve the imaging quality. In actual applications, the number and surface type of the second mirror can be designed according to actual requirements, and the present application only gives the above several examples, without specific limitation.

[0087] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all the preferred embodiments and all the changes and modifications falling within the scope of the present application.

[0088] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A head-up display device, wherein, The head-up display device comprises a light source, a polarization beam splitter, a first liquid crystal panel and a second liquid crystal panel; the light source is used for emitting natural light; the polarization beam splitter is located on the light emitting side of the light source and is used for transmitting first polarized light and reflecting second polarized light, the polarization directions of the first linear polarized light and the second linear polarized light are perpendicular; The first linear polarized light in the light emitted by the light source is transmitted to the first liquid crystal panel by the polarization beam splitter, the first linear polarized light is modulated by the first liquid crystal panel and converted into second linear polarized light which is reflected to the polarization beam splitter, the second linear polarized light is projected to the windshield with a first object distance through the polarization beam splitter and imaged with a first image distance after the windshield; The second linear polarized light in the light emitted by the light source is reflected to the second liquid crystal panel by the polarization beam splitter, the second linear polarized light is modulated by the second liquid crystal panel and converted into first linear polarized light which is reflected to the polarization beam splitter, the first linear polarized light is projected to the windshield with a second object distance through the polarization beam splitter and imaged with a second image distance after the windshield; the second object distance is different from the first object distance, and the second image distance is different from the first image distance.

2. The head-up display device of claim 1, wherein, The first liquid crystal panel and the second liquid crystal panel are configured to: the relative position of the first liquid crystal panel and the polarization beam splitter is adjustable, so that the first object distance and the first image distance are adjustable; and / or, the relative position of the second liquid crystal panel and the polarization beam splitter is adjustable, so that the second object distance and the second image distance are adjustable.

3. The head-up display device of claim 2, wherein, The head-up display device further comprises a first sliding rail, the first sliding rail is movably connected with the first liquid crystal panel, and the first liquid crystal panel moves along the first sliding rail to change the first object distance and the first image distance.

4. The head-up display device according to claim 2 or 3, wherein The head-up display device further comprises a second sliding rail, the second sliding rail is movably connected with the second liquid crystal panel, and the second liquid crystal panel moves along the second sliding rail to change the second object distance and the second image distance.

5. The head-up display device of claim 4, wherein, The size of the second liquid crystal panel is smaller than the size of the first liquid crystal panel, and the head-up display device further comprises a third sliding rail for moving the second liquid crystal panel in a plane perpendicular to the extension direction of the second sliding rail.

6. The head-up display device according to any one of claims 1 to 5, wherein The light source, the polarization beam splitter and the first liquid crystal panel are arranged in a first direction in sequence, the second liquid crystal panel and the polarization beam splitter are arranged in a second direction, and the second direction is perpendicular to the first direction; The interval of the first liquid crystal panel and the polarization beam splitter in the first direction is different from the interval of the second liquid crystal panel and the polarization beam splitter in the second direction.

7. The head-up display device of claim 6, wherein, The orthographic projection of the polarization beam splitter in the first direction covers the orthographic projection of the first liquid crystal panel in the first direction; The orthographic projection of the polarization beam splitter in the second direction covers the orthographic projection of the second liquid crystal panel in the second direction.

8. The head-up display device of any one of claims 1-5, wherein, The light source and the polarization beam splitter are arranged in a first direction, the second liquid crystal panel and the polarization beam splitter are arranged in a second direction, and the second direction is perpendicular to the first direction; The head-up display device further comprises a first reflector, which is located on a light path between the polarization beam splitter and the first liquid crystal panel, and is arranged at a set angle with the first direction.

9. The head-up display device of claim 8, wherein, The first liquid crystal panel and the second liquid crystal panel are spliced with each other.

10. The head-up display device according to any one of claims 1 to 9, wherein, The head-up display device further comprises at least one second reflector, which is used for reflecting light rays emitted by the polarization beam splitter to a windshield.

11. The head-up display device of claim 10, wherein, The at least one second reflector comprises a free-form surface reflector.

12. The head-up display device of claim 11, wherein, The at least one second reflector further comprises a planar reflector, which is located on a light path between the polarization beam splitter and the free-form surface reflector, and is used for reflecting light rays emitted by the polarization beam splitter to the free-form surface reflector.

Images