Display module, head-up display
By employing image light with different polarization directions and polarized light component processing technology in the HUD system, the problems of light crosstalk and excessive device size have been solved, achieving improvements in image clarity and size, making it suitable for head-up displays.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUAQIN TECH CO LTD
- Filing Date
- 2025-01-20
- Publication Date
- 2026-07-21
AI Technical Summary
Existing HUD systems suffer from light crosstalk, resulting in unclear images. Furthermore, their multi-path design leads to excessively large device sizes, making them unsuitable for the limited installation space in some vehicle models.
An imaging component emits first and second image lights with different polarization directions. These lights are then processed by a polarization light component, so that only light with a specific polarization direction is directly transmitted to the display component. The second image light is converted to the same polarization direction as the first image light after polarization adjustment, thereby reducing crosstalk and improving image clarity.
It effectively avoids cross-lighting between different optical paths, significantly reduces stray light and contrast degradation, improves image clarity and quality, and reduces the overall size of the HUD.
Smart Images
Figure CN122431007A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of image processing technology, and more particularly to a display module and a head-up display. Background Technology
[0002] A head-up display (HUD), as an advanced driver assistance technology, aims to enhance driving safety and convenience by projecting key driving information directly into the driver's line of sight. This display method allows drivers to obtain important information, such as vehicle speed, navigation instructions, and warning signals, without taking their eyes off the road, thereby reducing the likelihood of distraction from looking at the instrument panel or center console screen.
[0003] Currently, multi-focal-plane HUD systems on the market employ either a single image generation unit (PGU) combined with a multi-optical-path design, or multiple PGUs to simultaneously display virtual images at different focal lengths. The former ensures that the driver can clearly see information at different distances through complex optical paths, while the latter provides a dedicated image source for each desired focal plane through independent PGUs, thereby meeting diverse visual needs and optimizing the user experience.
[0004] However, existing HUDs suffer from unclear images due to light crosstalk during use. Summary of the Invention
[0005] This application provides a display module and a head-up display to improve the clarity of image display.
[0006] In a first aspect, embodiments of this application provide a display module, including an imaging component and a polarization adjustment component; wherein...
[0007] Imaging components are used to emit first and second image lights with different polarization directions;
[0008] A polarized light component is disposed opposite to the imaging component along the emission directions of the first image light and the second image light. It is used to receive the first image light and the second image light, and after adjusting the polarization direction of the second image light, it transmits the adjusted third image light and the first image light to the display component. The first image light is transmitted to the display component to display an image corresponding to the first image light and the third image light on the display component. The third image light and the first image light are image lights that satisfy the polarization direction conditions.
[0009] In one possible implementation, the imaging components include a display and a phase delay element:
[0010] A display used to emit light for the first image;
[0011] A phase delay element is disposed opposite to the display along the emission direction of the first image light and is used to adjust the polarization direction of the first image light emitted from the target emission area in the display to obtain a second image light that satisfies the first polarization condition.
[0012] In one possible implementation, when the light emitted by the display is unpolarized, the imaging assembly further includes a linear polarizer and a diffuser screen sequentially disposed on the display along the light emission direction, wherein:
[0013] A linear polarizer is used to receive light emitted by a display and to polarize the light emitted by the display to obtain the first image light.
[0014] A diffusion screen is used to adjust the diffusion of the first image light and send the adjusted first image light to a phase delay element.
[0015] In one possible implementation, the polarization light assembly includes a polarization beam splitter and a polarization conversion element, wherein:
[0016] A polarization beam splitter is disposed opposite to the imaging assembly along the emission directions of the first image light and the second image light, and is used to reflect the first image light that meets the second polarization condition to the display assembly and to transmit the second image light that does not meet the second polarization condition to the polarization conversion component.
[0017] A polarization conversion element is disposed opposite to the polarization beam splitter along the optical path propagation direction of the second image light. It is used to adjust the polarization direction of the second image light, and the third image light that meets the second polarization condition after adjustment enters the polarization beam splitter so as to be transmitted to the display component through the polarization beam splitter.
[0018] In one possible implementation, the polarization beam splitter includes a polarization beam splitting film and a substrate, wherein one side of the substrate is disposed opposite to the imaging component, and the other side of the substrate is disposed opposite to the polarization conversion component.
[0019] The polarizing beam splitter is fixedly disposed on one side and / or the other side of the substrate.
[0020] In one possible implementation, the polarization beam splitter further includes an anti-reflective film, which is attached to opposite sides of the substrate.
[0021] In one possible implementation, the polarization conversion element includes a phase retarder and a first reflector, wherein:
[0022] A phase delayer is disposed opposite to the polarization beam splitter along the transmission direction of the second image light. It is used to adjust the vibration direction of the second image light to obtain adjusted polarized light, and transmit the adjusted polarized light to the first reflector. It also adjusts the polarization direction of the adjusted polarized light reflected from the first reflector and transmits the adjusted third image light that meets the polarization direction condition to the polarization beam splitter.
[0023] The first reflector is positioned opposite the phase delayer along the propagation direction of the adjusted polarized light, and is used to reflect the adjusted polarized light to the phase delayer.
[0024] In one possible implementation, it also includes:
[0025] The second reflector is used to reflect the first image light and the third image light to the display component.
[0026] In one possible implementation, the angle between the first image light and the third image light ranges from 20° to 60°.
[0027] Secondly, embodiments of this application provide a head-up display, including the display module of any one of claims 1-9.
[0028] This application provides a display module and a head-up display that emits first and second image lights with different polarization directions through an imaging component. When these lights pass through a polarization component, only the first image light with a specific polarization direction is directly transmitted to the display component, while the second image light is transmitted to the display component only after its polarization direction is adjusted to become a third image light with the same polarization direction as the first image light. This ensures that all light reaching the display component has the same polarization direction, effectively preventing light from accidentally entering another optical path in one image light path, thus reducing crosstalk and improving image display clarity. Attached Figure Description
[0029] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0030] Figure 1 A schematic diagram of a scenario for the head-up display provided in this application;
[0031] Figure 2 This is a schematic diagram of the structure of the display module provided in this application;
[0032] Figure 3 This is a schematic diagram of the imaging component provided in an embodiment of this application;
[0033] Figure 4This is a schematic diagram of the imaging component provided in an embodiment of this application;
[0034] Figure 5 This is a schematic diagram of the structure of the polarization light component provided in the embodiments of this application;
[0035] Figure 6 A schematic diagram of the structure of the polarization beam splitter provided in the embodiments of this application. Figure 1 ;
[0036] Figure 7 A schematic diagram of the structure of the polarization beam splitter provided in the embodiments of this application. Figure 2 ;
[0037] Figure 8 This is a schematic diagram of the optical path propagation of the display module provided in an embodiment of this application.
[0038] Figure label:
[0039] 100 - Imaging assembly; 110 - Display; 111 - Linear polarizer; 112 - Diffuser; 120 - Phase retardation element; 200 - Polarized light assembly; 210 - Polarized beam splitter; 211 - Polarized beam splitting film; 212 - Substrate; 220 - Polarization conversion element; 221 - Phase retarder; 222 - First reflector; 213 - Reflective film; 300 - Display assembly; 400 - Second reflector; 501 - First image light; 502 - Second image light; 503 - First rotation direction adjustment polarized light; 504 - Second rotation direction adjustment polarized light; 505 - Third image light; 600 - Windshield.
[0040] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation
[0041] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.
[0042] First, let me explain the terms used in this application:
[0043] The PGU (Picture Generation Unit) is one of the core components of a head-up display (HUD) system. It is responsible for generating the image information to be projected onto the windshield or other transparent medium. The PGU typically includes a light source, imaging elements (such as an LCD, LCoS, or DLP chip), and necessary optical elements (such as lenses and mirrors).
[0044] LCD (Liquid Crystal Display) refers to a display technology used in electronic devices that modulates light by controlling the electro-optic effect of liquid crystal materials to generate image light.
[0045] The polarization direction can refer to the direction of electric field vibration in a light wave, and is used to describe the directional vibration of the electric vector of the light wave during propagation.
[0046] Currently, to avoid safety issues caused by the driver's eye switching back and forth between observing the external environment and the HUD virtual image, HUDs currently use multiple virtual image distance optical paths to display virtual images with different focal lengths.
[0047] However, current head-up display (HUD) technologies that employ a single image generation unit (PGU) with a multi-path design to achieve multi-focal displays generally encounter challenges related to light crosstalk and excessive device size. Light crosstalk refers to the interference between signal rays from different image paths, which not only causes unwanted stray light but also reduces image contrast and affects visual clarity. Simultaneously, the large physical size resulting from this design makes multi-focal HUDs difficult to fit into the limited installation space of some vehicle models. Therefore, solving the light crosstalk problem and reducing the overall size of the HUD are crucial for improving user experience and expanding product applicability.
[0048] The display module and head-up display provided in this application employ imaging components that emit first and second image lights with different polarization directions. These lights are then processed by a polarization light component to ensure that only the first image light with a specific polarization direction is directly transmitted to the display component. The second image light, after polarization adjustment, is converted into a third image light with the same polarization direction as the first image light before being transmitted to the display component. This ensures that all light reaching the display component has uniform polarization characteristics, effectively avoiding crosstalk between different optical paths, significantly reducing stray light and contrast degradation, and thus improving the clarity and quality of the image display.
[0049] Figure 1 A schematic diagram of the scene of the head-up display provided in this application, such as Figure 1As shown, the specific application scenario of this application is that the head-up display is installed in a car to project vehicle status information, external object indication information, and navigation information into the driver's field of vision.
[0050] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.
[0051] Figure 2 A schematic diagram of the display module provided in this application is shown below. Figure 2 As shown, the display module includes: an imaging component 100, a polarizing light component 200, and a display component 300; wherein,
[0052] Imaging component 100 is used to emit first image light and second image light with different polarization directions;
[0053] The polarization light component 200 is disposed opposite to the imaging component 100 along the emission directions of the first image light and the second image light. It is used to receive the first image light and the second image light, and after adjusting the polarization direction of the second image light, it transmits the adjusted third image light and the first image light to the display component 300 so as to display an image corresponding to the first image light and the third image light on the display component 300. The third image light and the first image light are image lights that satisfy the polarization direction conditions.
[0054] The imaging component 100 can be one of the core components in the head-up display, responsible for providing the necessary image light energy to generate an image.
[0055] Image light can refer to light emitted by the imaging component 100 and modulated to form light carrying specific image information and having specific polarization characteristics. This light is processed by a series of optical elements (such as lenses, mirrors and polarizers) and propagates according to a predetermined design path, and is finally projected onto the display surface or the observer's eye to form a visible image.
[0056] In this embodiment of the application, the image light can be linearly polarized light. Linearly polarized light refers to light whose electric field vibration direction is confined to a single plane. The electric field vector of linearly polarized light vibrates along a fixed direction, which can be called the polarization direction.
[0057] Linearly polarized light can be divided into S-light and P-light according to the different polarization directions. S-light (vertically polarized light) vibrates perpendicularly to the incident plane, while P-light (parallel polarized light) vibrates parallel to the incident plane.
[0058] The first image light can refer to S-light whose light vibration direction is perpendicular to the incident surface, and the second image light can refer to P-light whose light vibration direction is parallel to the incident surface.
[0059] Optionally, the imaging assembly 100 can generate a first image light and a second image light, wherein the first and second image lights are separated into S-beams and P-beams by a polarizer placed in the optical path. Alternatively, a crystalline material with birefringence (such as calcite or quartz) can be used to separate the incident unpolarized light into S-beams and P-beams using a polarizing beam splitter. Multiple laser diodes can also be configured to simultaneously provide S-beams and P-beams within the same imaging assembly 100.
[0060] In a head-up display, the image light is generated by the PGU, transmitted through the optical path, and projected onto the windshield, allowing the driver to clearly see important information such as navigation prompts and vehicle speed without taking their eyes off the screen.
[0061] PGU can include any one of the following modules: LCD (Liquid Crystal Display) module, DLP (Digital Light Processing) module, LCOS (liquid crystal on silicon) module, or LBS (Laser Beam Scanning) module.
[0062] For a head-up display using an LCD module, the imaging assembly 100 may include a backlight module, an LCD screen, and a half-wave plate. The half-wave plate is attached to the first image light and is used to apply a phase delay to the linearly polarized light emitted from the LCD screen. The fast axis (or slow axis) of the half-wave plate is at a 45° angle to the transmission axis of the polarizer on the LCD screen.
[0063] For a head-up display using an LCOS module, the imaging assembly 100 may include a projection engine, a diffuser screen, and a half-wave plate. The projection engine and diffuser screen together form the PGU (Projection Unit). The half-wave plate can be attached to the lower or upper surface of the diffuser screen, or it can be attached to a glass substrate and positioned behind the diffuser screen.
[0064] For head-up displays using DLP or LBS modules, the imaging assembly 100 may include a projection engine, a diffuser screen, a linear polarizer, and a half-wave plate. The projection engine and diffuser screen constitute the PGU (Projection Unit). The linear polarizer and half-wave plate can be attached to the lower or upper surface of the diffuser screen, or they can be attached to a glass substrate and placed behind the diffuser screen. The fast axis (or slow axis) of the half-wave plate is at a 45° angle to the transmission axis of the linear polarizer.
[0065] The polarization light component 200 can refer to a component used to control and adjust the polarization state of light. The polarization light component 200 can selectively transmit or reflect light with a specific polarization direction and can convert or separate beams of light with different polarization states. In a head-up display, the polarization light component 200 receives first image light and second image light from the imaging component 100, and adjusts the polarization direction of the second image light to match that of the first image light, ensuring that all light reaching the display component 300 has the same polarization characteristics. This effectively reduces crosstalk and improves image clarity and contrast.
[0066] In some embodiments, the polarization component 200 can be an optical element such as a polarization beam splitter (PBS) or a polarizer. For example, when the polarization component 200 is a polarization beam splitter, the S-ray and P-ray can be separated by adjusting the optical coating or material properties on the surface of the polarization beam splitter.
[0067] For example, when the first image light and the second image light enter the polarization light component 200, the first image light (S light) can be reflected to the display component 300, and after the second image light is polarized, the P light is adjusted to the S light (third image light) and then introduced into the display component 300.
[0068] Display component 300 can refer to the part that presents the image to the user, specifically the component used to carry and reflect the first image light and the third image light. In the embodiments of this application, display component 300 can be a transparent or semi-transparent medium, such as a windshield. When it is a windshield, it can be used to receive light that has undergone a series of optical processing and reflect it back to the user's eyes to form a clearly visible virtual image.
[0069] In this embodiment of the application, the display module further includes:
[0070] The second reflector 400 is used to reflect the first image light and the third image light to the display component 300.
[0071] The second reflector 400 is used to reflect the first image light and the third image light to the display component 300 so as to form an image on the display component 300. For example, when the display module is used for a head-up display, the second reflector 400 can reflect the first image light and the third image light onto the windshield.
[0072] In this embodiment, the second reflector 400 can be a plane mirror or a freeform mirror. Its substrate can be glass, plastic (PC, PMMA, COC, etc.), or metal, and its surface can be coated with a high-reflection film or have a high-reflection film applied. The second reflector 400 adjusts its angle with the first image light and the third image light, thereby enabling the first image light and the third image light to form an image on the windshield.
[0073] In some embodiments, the number of second reflectors 400 may be one or two. When there is one, the second reflector 400 can reflect both the first image light and the third image light. When there are two, one of the second reflectors 400 can be used to reflect the first image light, and the other can be used to reflect the third image light.
[0074] Figure 3 This is a schematic diagram of the imaging component provided in an embodiment of this application. Figure 3 As shown, the imaging assembly 100 includes a display 110 and a phase delay member 120. The display 110 is used to emit a first image light. The phase delay member 120 is disposed opposite to the display 110 along the emission direction of the first image light and is used to adjust the polarization direction of the first image light emitted from the target emission area in the display 110 to obtain a second image light that satisfies the first polarization condition.
[0075] The display 110 can be an LCD screen, and the surface of the LCD screen can emit first image light emitted by the backlight module. For example, the surface of the LCD screen can emit linearly polarized light in the S direction through the backlight module.
[0076] In this embodiment, the uniform unpolarized light provided by the backlight module first passes through a polarizer below the display 110, which only allows linearly polarized light in the P-direction to pass through. Subsequently, as the light passes through the liquid crystal layer, the liquid crystal molecules change the phase of the light according to the applied voltage, causing the polarization direction to rotate. For an LCD screen used in a head-up display, there is an orthogonally placed polarizer at the top and bottom. The lower polarizer allows P-light to pass through, while the upper polarizer ensures that only linearly polarized light in the S-direction can be emitted. Through the electro-optic effect, the liquid crystal layer applies a phase delay to the incident light, converting the P-light into S-light. Finally, the light emitted from the upper polarizer is S-direction linearly polarized image light, thereby forming a visible image.
[0077] The phase delay element 120 can refer to an optical element used to adjust the polarization state of light, which can change the polarization characteristics of light by introducing different phase delays in two orthogonal polarization directions. In the embodiments of this application, the phase delay element 120 can adjust the S-direction linearly polarized light emitted in the target emission region to the P-direction linearly polarized light (first polarization condition).
[0078] The target emission area can refer to any area on the display 110. The images displayed in the target emission area and other areas can correspond to images on different focal planes of the head-up display 110. For example, the display 110 can be divided into a left screen and a right screen as needed, and the target emission area can refer to the area containing either the left or right screen. Figure 3As shown, the LCD screen emits S-direction linearly polarized light upwards, and the phase delay element 120 is positioned opposite the right half of the LCD screen to convert the S-direction linearly polarized light into P-direction linearly polarized light.
[0079] Optionally, when there are multiple LCD screens, the target emission area can be any number of LCD screens. It should be noted that to avoid excessive space occupied by multiple LCD screens, the size of each LCD screen can be adjusted as needed.
[0080] Figure 4 This is a schematic diagram of the imaging component provided in an embodiment of this application. Figure 4 As shown, when the light emitted by the display is unpolarized, the imaging assembly 100 further includes a linear polarizer 111 and a diffusion screen 112 sequentially disposed on the display along the light emission direction. The linear polarizer 111 is used to receive the light emitted by the display and to polarize the light emitted by the display to obtain the first image light. The diffusion screen 112 is used to diffuse and adjust the first image light and send the diffused and adjusted first image light to the phase delay unit 120.
[0081] Unpolarized light refers to light whose vibration direction is randomly distributed and has no specific polarization direction. For example, unpolarized light emitted by ordinary light sources such as incandescent lamps and LEDs.
[0082] A linear polarizer 111 can be an optical element that allows light vibrating in a specific direction to pass through, thereby converting unpolarized light into linearly polarized light.
[0083] The diffuser screen 112 is an optical element used to scatter light. It can diffuse light evenly, making the image softer and the viewing angle wider. The function of the diffuser screen 112 is to adjust the propagation direction of the light in the first image, ensuring uniform light distribution and reducing hotspot effects, and then send the diffused and adjusted light to the next processing element.
[0084] In this embodiment, when the light emitted by the display is unpolarized, the linear polarizer 111 and the diffuser 112 are disposed between the display and the phase delay member 120. The linear polarizer 111 can be attached to the front side of the diffuser 112 along the light emitted by the display to polarize the unpolarized light so that linearly polarized light in the S direction is emitted from the surface of the diffuser 112. The phase delay member 120, which is disposed opposite to the target emission area in the display, can be used to convert the incident linearly polarized light in the S direction into linearly polarized light in the P direction.
[0085] Figure 5 This is a schematic diagram of the structure of a polarizing light component provided in an embodiment of this application. Figure 5As shown, the polarization light assembly includes a polarization beam splitter 210 and a polarization conversion element 220, wherein:
[0086] The polarization beam splitter 210 is disposed opposite to the imaging assembly 100 along the emission directions of the first image light and the second image light, and is used to reflect the first image light that meets the second polarization condition to the display assembly 300 and to transmit the second image light that does not meet the second polarization condition to the polarization conversion member 220.
[0087] The polarization conversion element 220 is disposed opposite to the polarization beam splitter 210 along the optical path propagation direction of the second image light. It is used to adjust the polarization direction of the second image light and then the third image light that meets the second polarization condition is incident on the polarization beam splitter 210 so as to be transmitted to the display component 300 through the polarization beam splitter 210.
[0088] The polarization beam splitter 210 is used to directly reflect light that meets the second polarization condition (linearly polarized light in the S direction) to the display component 300, and to transmit light that does not meet the second polarization condition (linearly polarized light in the P direction) to the polarization conversion component 220.
[0089] The polarization converter 220 can refer to an optical device capable of changing the polarization state of light. Specifically, the polarization converter 220 is located in the optical path after the polarization beam splitter 210, and is used to adjust the polarization direction of second image light that fails to meet the second polarization condition (i.e., linearly polarized light in the P direction), converting it into third image light that meets the linear polarization requirement in the S direction.
[0090] In some embodiments, the polarization converter 220 can be a polarization control device such as a waveplate or a polarization rotator. After adjusting the polarization direction of the second image light through the polarization converter 220 to obtain the third image light that meets the second polarization condition, the third image light can be redirected back to the polarization beam splitter 210 and finally transmitted to the display component 300 through reflection, ensuring that all image light reaches its destination with the correct polarization state, thereby optimizing image quality and display effect.
[0091] In this embodiment of the application, the polarization conversion element 220 includes a phase delayer 221 and a first reflector 222. The phase delayer 221 is disposed opposite to the polarization beam splitter 210 along the transmission direction of the second image light, and is used to adjust the vibration direction of the second image light to obtain adjusted polarized light, and transmit the adjusted polarized light to the first reflector 222.
[0092] The first reflector 222 is disposed opposite to the phase delayer 221 along the propagation direction of the adjusted polarized light, and is used to reflect the adjusted polarized light to the phase delayer 221 so that it can be transmitted to the display component 300 through the polarization beam splitter 210.
[0093] The vibration direction can characterize the path of the electric field vector in the light wave as it changes over time. Depending on the vibration direction, polarized light can be divided into linearly polarized light, elliptically polarized light, and circularly polarized light. In the embodiments of this application, the second image light as P light and the first image light as S light are linearly polarized light. The polarized light can be elliptically polarized light or circularly polarized light.
[0094] The phase delayer 221 is an optical device used to adjust the vibration direction of polarized light. In this embodiment, the phase delayer 221 is used to convert the polarization state of the second image light, that is, to convert linearly polarized light in the second polarization direction into polarized light in other vibration directions. After being reflected by the first reflector 222, the polarized light changes its rotation direction and becomes linearly polarized light in the S direction again after passing through the phase delay period. Thus, it can pass through the polarization beam splitter.
[0095] The phase delayer 221 can take various forms. It can be a combination of a quarter-wave plate and a glass substrate. The fast or slow axis of the quarter-wave plate is at a 45° angle to the transmission axis of the polarization beam splitter.
[0096] The phase delayer 221 can be combined with the polarization beam splitter 210 and their positions can be changed. For example, a polarization beam splitter film (polarization beam splitter device) is attached to the first side of the glass substrate, and a quarter-wave plate is attached to the second side. Alternatively, a composite film material of a quarter-wave plate and a polarization beam splitter film can be attached to the first side.
[0097] In this embodiment, the phase delayer 221 can convert the incident linearly polarized light (second image light) in the P direction into circularly polarized light (adjusted polarization light) in the first rotation direction, and then guide the circularly polarized light in the first rotation direction to the first reflector 222. The first reflector 222 converts the circularly polarized light in the first rotation direction into circularly polarized light in the second rotation direction, and then the returning circularly polarized light in the second rotation direction is converted into linearly polarized light (third image light) in the S direction by the polarization beam splitter 210.
[0098] Figure 6 A schematic diagram of the structure of the polarization beam splitter provided in the embodiments of this application. Figure 1 .like Figure 6 As shown, the polarization beam splitter includes a polarization beam splitter film 211 and a substrate 212. One side of the substrate 212 is disposed opposite to the second reflector 400 in the imaging assembly 100 and the display assembly 300, respectively, and the other side of the substrate 212 is disposed opposite to the polarization conversion component 220. The polarization beam splitter film 211 is fixedly disposed on one side and / or the other side of the substrate 212.
[0099] The substrate 212 can refer to a transparent glass sheet that serves as a support structure and optical medium. The substrate 212 can not only provide physical support, but also participate in the transmission and processing of light.
[0100] In this embodiment, the substrate 212 can be a glass substrate, which may include a first surface on one side and a second surface on the other side. The polarizing beam splitter 211 is attached to either the first or second surface of the glass substrate. Figure 6 As shown in Figure a, the polarizing beam splitter 211 can be attached to the first surface (lower surface) of the glass substrate, as follows: Figure 6 As shown in b, the polarizing beam splitter 211 can be attached to the second surface (upper surface) of the glass substrate.
[0101] When the polarizing beam splitter 211 is attached to the first or second surface of the glass substrate, the second or first surface of the glass substrate can also be coated with other film materials such as anti-reflective film to improve the optical display effect.
[0102] In some embodiments, polarizing beam-splitting films 211 can be attached to both the first and second surfaces of the glass substrate. This further blocks the light path of the first signal light, allowing it to enter the light path of the second signal light, thereby improving image contrast. For example... Figure 6 As shown in c, the polarizing beam splitter 211 can be attached to the first and second surfaces of the glass substrate.
[0103] When the polarizing beam splitter 211 is attached to the first or second surface of the glass substrate, a linear polarizing film can be attached to the second or first surface of the glass substrate. The transmission axis of the linear polarizing film is aligned with the transmission axis of the polarizing beam splitter 211, and is used to block the light path of the first image light and allow the second image light to enter, thereby improving the display effect.
[0104] Figure 7 A schematic diagram of the structure of the polarization beam splitter provided in the embodiments of this application. Figure 2 .like Figure 7 As shown, the polarization beam splitter also includes an anti-reflection film 213, and the anti-reflection film 213 and the polarization beam splitter 211 are attached to opposite sides of the substrate 212.
[0105] Among them, the anti-reflection coating 213 (AR film) can be used to reduce reflections on the surface of optical components, thereby improving light transmittance and image quality. The anti-reflection coating 213 is formed by creating one or more thin films with a specific refractive index on the surface of glass or other transparent substrates, causing the reflections of incident light at the interfaces of different media to interfere and cancel each other out, effectively reducing reflection loss. In head-up displays, the AR film can significantly reduce glare and ghosting, enhance contrast and clarity, and provide a brighter, sharper visual experience. Furthermore, the AR film can protect optical surfaces from scratches and environmental factors, extending the lifespan of the device.
[0106] In some implementations, such as Figure 7 As shown in Figure a, along the optical path propagation directions of the first image light and the second image light, the polarizing beam splitter 211 and the anti-reflection film 213 are attached to the lower and upper surfaces of the glass substrate, respectively. Figure 7 As shown in b, along the optical path propagation direction of the first image light and the second image light, the polarizing beam splitter 211 and the anti-reflection film 213 are attached to the upper and lower surfaces of the glass substrate.
[0107] Figure 8 This is a schematic diagram of the optical path propagation of the display module provided in the embodiments of this application, as shown below. Figure 8 As shown, the imaging component 100 emits a first image light 501 and a second image light 502 that are parallel to each other. The first image light 501 is reflected to the second reflector 400 by a tilted polarizing beam splitter 210, and the second image light 502 is transmitted through the polarizing beam splitter 210 to the phase delayer 221. The phase delayer 221 adjusts the vibration direction of the second image light 502 to obtain an adjusted polarized light 503 with a first rotation direction. The adjusted polarized light 503 with the first rotation direction is transmitted through the tilted first... The reflector 222 reflects the light, thereby adjusting the polarized light 503 from the first rotation direction to the polarized light 504 from the second rotation direction. The polarized light 504 from the second rotation direction is then reflected to the phase delay unit 221. The phase delay unit 221 adjusts the polarized light 504 from the second rotation direction to the third image light 505, which is then transmitted to the first reflector 222. The first reflector 222 then reflects the first image light 501 and the third image light 505 to the windshield 600, thereby realizing the display of the image.
[0108] The first rotation direction and the second rotation direction are set opposite to each other, that is, when the first rotation direction is left-handed, the second rotation direction is right-handed.
[0109] The angle between the polarized light 503 adjusted by the first rotation direction and the polarized light 504 adjusted by the second rotation direction is in the range of 10~50°.
[0110] The angle between the first image light 501 and the third image light 505 is in the range of 20~60°.
[0111] For example, when the angle between the first rotation direction-adjusted polarized light 503 and the second rotation direction-adjusted polarized light 504 reflected by the first reflector 222 is 10°, the angle between the first image light 501 and the third image light 505 can be 60°.
[0112] When the angle between the first rotation direction-adjusted polarized light 503 and the second rotation direction-adjusted polarized light 504 reflected by the first reflector 222 is 50°, the angle between the first image light 501 and the third image light 505 can be 20°.
[0113] When the angle between the first rotation direction-adjusted polarized light 503 and the second rotation direction-adjusted polarized light 504 reflected by the first reflector 222 is 30°, the angle between the first image light 501 and the third image light 505 can be 40°.
[0114] Both the first reflector 222 and the second reflector 400 can be curved mirrors, with the sagittal distribution range of the curved mirrors being 0~70.
[0115] The display module provided in this application, by optimizing the optical path and utilizing the characteristics of polarized light, achieves a small-volume, high-image-contrast multi-focal-plane head-up display device. The imaging component emits a first image light and a second image light with different polarization directions, while the polarization component receives these two beams and adjusts only the polarization direction of the second image light to convert it to the same polarization direction as the first image light, forming a third image light. In this way, two image lights satisfying the same polarization condition can be effectively combined and transmitted to the display component via a polarization beam splitter.
[0116] Meanwhile, by using polarization control technology to manage the optical path, the need for additional mirrors or prisms in traditional HUD systems can be avoided, thus reducing the overall system size. Furthermore, by precisely controlling the polarization state of the light entering the display component, unnecessary light scattering and leakage can be effectively reduced, improving image contrast and clarity. In addition, the multi-focal plane function can be achieved by adjusting the polarization conversion in the polarization light component, allowing different image focal positions to be superimposed in the same field of view without increasing physical depth, thereby supporting more complex display effects, such as 3D information display or multi-layer information overlay. Thus, a small-volume display module with high image contrast can be achieved at a low cost.
[0117] This application also provides a head-up display, which includes the display module described in this application embodiment.
[0118] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.
Claims
1. A display module, characterized in that, Includes imaging components and polarization adjustment components; among which, The imaging component is used to emit first image light and second image light with different polarization directions; The polarization light component is disposed opposite to the imaging component along the emission directions of the first image light and the second image light. It is used to receive the first image light and the second image light, and after adjusting the polarization direction of the second image light, transmit the adjusted third image light and the first image light to the display component so as to display an image corresponding to the first image light and the third image light on the display component. The third image light and the first image light are image lights that satisfy the polarization direction condition.
2. The display module according to claim 1, characterized in that, The imaging assembly includes a display and a phase delay element: The display is used to emit the first image light; The phase delay element is disposed opposite to the display along the emission direction of the first image light, and is used to adjust the polarization direction of the first image light emitted from the target emission area in the display to obtain a second image light that satisfies the first polarization condition.
3. The display module according to claim 2, characterized in that, When the light emitted by the display is unpolarized, the imaging assembly further includes a linear polarizer and a diffuser screen sequentially disposed on the display along the light emission direction, wherein: The linear polarizer is used to receive the light emitted by the display and to polarize the light emitted by the display to obtain the first image light. The diffusion screen is used to adjust the diffusion of the first image light and send the adjusted first image light to the phase delay element.
4. The display module according to claim 1, characterized in that, The polarization light assembly includes a polarization beam splitter and a polarization conversion component, wherein: The polarization beam splitter is disposed opposite to the imaging component along the emission directions of the first image light and the second image light, and is used to reflect the first image light that meets the second polarization condition to the display component, and to transmit the second image light that does not meet the second polarization condition to the polarization conversion component; The polarization conversion element is disposed opposite to the polarization beam splitter along the optical path propagation direction of the second image light. It is used to adjust the polarization direction of the second image light, and the third image light that meets the second polarization condition after adjustment enters the polarization beam splitter so as to be transmitted to the display component through the polarization beam splitter.
5. The display module according to claim 4, characterized in that, The polarization beam splitter includes a polarization beam splitting film and a substrate, wherein one side of the substrate is disposed opposite to the imaging component, and the other side of the substrate is disposed opposite to the polarization conversion component; The polarizing beam splitter is fixedly disposed on one side and / or the other side of the substrate.
6. The display module according to claim 5, characterized in that, The polarization beam splitter also includes an anti-reflective film, and the anti-reflective film and the polarization beam splitter are attached to opposite sides of the substrate.
7. The display module according to claim 4, characterized in that, The polarization conversion element includes a phase retarder and a first reflector, wherein: The phase delay unit is disposed opposite to the polarization beam splitter along the transmission direction of the second image light. It is used to adjust the vibration direction of the second image light to obtain adjusted polarized light, and transmit the adjusted polarized light to the first reflector. It also adjusts the polarization direction of the adjusted polarized light reflected from the first reflector and transmits the adjusted third image light that meets the polarization direction condition to the polarization beam splitter. The first reflector is disposed opposite to the phase delayer along the propagation direction of the adjusted polarized light, and is used to reflect the adjusted polarized light to the phase delayer.
8. The display module according to claim 1, characterized in that, Also includes: A second reflector is used to reflect the first image light and the third image light to the display component.
9. The display module according to any one of claims 1-8, characterized in that, The angle between the first image light and the third image light ranges from 20° to 60°.
10. A heads-up display, characterized in that, The display module includes any one of claims 1-9.