Head-up display system and display control method thereof

Abstract

The invention discloses a head-up display system and a display control method thereof. The head-up display system comprises a display screen, an imaging assembly, a protective cover, a controller and a tunable filter layer, the display screen sequentially emits primary light according to a set time sequence, and the controller determines a light emitting time sequence of the display screen and generates a driving electric signal according to the light emitting time sequence; the tunable filter layer is driven by the driving electric signal to block light rays with other wavelengths except the primary light through the primary light emitted by the current display screen. The tunable filter layer has wave vector selectivity, and when the display screen emits primary light according to a specific time sequence, the tunable filter layer can dynamically pass through the emergent light of the display screen, and light with other wavelengths is blocked, so that image display of the head-up display system is not affected, and the image quality is improved. In addition, sunlight entering the head-up display system can be effectively reduced, the head-up display system is protected, and the service life of the head-up display system is prolonged.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a head-up display system and a display control method thereof. Background Art

[0002] Head up display (HUD), also known as the head-up display system, uses projection technology to project instrument, driving and other information onto the windshield in front of the driver, allowing the driver to see driving information without lowering or turning his head, greatly improving driving safety.

[0003] The head-up display system may include a display screen and an imaging component. The image displayed on the display screen is incident on the windshield after being imaged by the imaging component, and finally reflected to the human eye. Due to the reversibility of the optical path, sunlight can converge on the display screen along the optical path of the imaging component at a certain angle, forming a high-energy-density sunlight distribution on the display screen. In the summer when the sun is exposed, the radiation power of the sunlight is relatively large, which will cause the temperature inside the head-up display system to rise, and it is very likely to burn the display screen and reduce its service life. Summary of the invention

[0004] According to a first aspect of an embodiment of the present invention, a head-up display system is provided, comprising:

[0005] A display screen, used for image display; the display screen emits primary color lights in sequence according to a set timing;

[0006] An imaging component, located at the light-emitting side of the display screen, used to image the image displayed on the display screen and then emit it to the windshield of the vehicle; the imaging component includes at least one optical lens, and the optical lens is used to image the image displayed on the display screen;

[0007] A protective cover, located between the imaging assembly and the windshield, for protecting the display screen and the imaging assembly;

[0008] A tunable filter layer is located on any surface of the display screen, the optical lens and the protective cover, and is used to block light of other wavelengths except the primary color light through the primary color light currently emitted by the display screen according to the light emission timing of the display screen;

[0009] A controller is electrically connected to the display screen and the tunable filter layer; the controller is used to determine the light emission timing of the display screen, and control the display screen to emit primary color lights in sequence according to the light emission timing, and control the tunable filter layer to block light of other wavelengths except the primary color light through the primary color light currently emitted by the display screen.

[0010] In some embodiments of the present invention, the imaging assembly includes a first reflector and a second reflector;

[0011] The outgoing light of the display screen is incident on the first reflector, and is reflected by the first reflector toward the second reflector. The second reflector reflects the incident light toward the protective cover, and the incident light passes through the protective cover and is incident on the windshield.

[0012] In some embodiments of the present invention, the tunable filter layer is located on the reflection surface of the first reflector; or, the tunable filter layer is located on the reflection surface of the second reflector;

[0013] The tunable filter layer is used to reflect the primary color light currently emitted by the display screen according to the light emission timing of the display screen, and block light of other wavelengths except the primary color light.

[0014] In some embodiments of the present invention, the tunable filter layer is located on the light emitting surface of the display screen; or, the tunable filter layer is located on any side surface of the protective cover;

[0015] The tunable filter layer is used to transmit the primary color light currently emitted by the display screen according to the light emission timing of the display screen, and block light of other wavelengths except the primary color light.

[0016] In some embodiments of the present invention, the tunable filter layer includes:

[0017] substrate;

[0018] an adjustment mechanism, located on the base;

[0019] The tunable dielectric layer is connected to the regulating mechanism; when an electrical signal is applied to the regulating mechanism, the tunable dielectric layer generates a periodic structure and has wave vector selectivity.

[0020] In some embodiments of the present invention, the substrate includes: a first substrate and a second substrate, wherein the first substrate and the second substrate are arranged opposite to each other;

[0021] The adjustment mechanism comprises: a first electrode and a second electrode, the first electrode being located on a side of the first substrate facing the second substrate, and the second electrode being located on a side of the second substrate facing the first substrate;

[0022] The tunable medium layer includes: a liquid crystal layer located between the first electrode and the second electrode;

[0023] The first electrode and the second electrode are used to apply electrical signals according to the light emission timing of the display screen, so that an electric field is generated between the first electrode and the second electrode to change the refractive index of the liquid crystal layer, so that the refractive index of the liquid crystal layer changes periodically to form a diffraction grating.

[0024] In some embodiments of the present invention, the substrate includes: a first substrate and a second substrate, wherein the first substrate and the second substrate are arranged opposite to each other;

[0025] The adjustment mechanism comprises: a first electrode and a second electrode, the first electrode being located on a side of the first substrate facing the second substrate, and the second electrode being located on a side of the second substrate facing the first substrate;

[0026] The tunable medium layer includes: a liquid crystal layer located between the first electrode and the second electrode; and a microstructure layer located between the first electrode and the liquid crystal layer, or between the second electrode and the liquid crystal layer;

[0027] The first electrode and the second electrode are used to be applied with electrical signals according to the light emission timing of the display screen, so that the refractive index of the liquid crystal layer changes and resonates with the super surface formed by the microstructure layer.

[0028] In some embodiments of the present invention, the head-up display system further includes:

[0029] A photoelectric sensor, electrically connected to the controller, the photoelectric sensor is located in the optical path of the outgoing light of the display screen, and is used to detect the wavelength of the outgoing light of the display screen;

[0030] The controller controls the tunable filter layer to pass the light of the currently detected wavelength and block the light of other wavelengths according to the wavelength detected by the photoelectric sensor.

[0031] A second aspect of an embodiment of the present invention provides a display control method for a head-up display system, comprising:

[0032] The display screen emits primary color lights in sequence according to the set timing;

[0033] The controller determines the light emission timing of the display screen and generates a driving electrical signal according to the light emission timing;

[0034] Driven by the driving electrical signal, the tunable filter layer passes the primary color light currently emitted by the display screen and blocks light of other wavelengths except the primary color light.

[0035] In some embodiments of the present invention, the head-up display system is further provided with a photoelectric sensor; and the method further comprises:

[0036] The photoelectric sensor detects the wavelength of the light currently emitted from the display screen;

[0037] The controller generates a driving electrical signal according to the wavelength detected by the photoelectric sensor;

[0038] The tunable filter layer, driven by the driving electrical signal, passes the light of the currently detected wavelength and blocks the light of other wavelengths.

[0039] In the head-up display system and display control method provided by the embodiment of the present invention, the display screen emits primary color lights in sequence according to the set timing; the controller determines the light emission timing of the display screen and generates a driving electrical signal according to the light emission timing; the tunable filter layer passes the primary color light emitted by the current display screen under the drive of the driving electrical signal and blocks light of other wavelengths except the primary color light. The tunable filter layer has wave vector selectivity. When the display screen emits three primary color lights according to a specific timing, the tunable filter layer can dynamically pass the emitted light of the display screen, and light of other wavelengths is blocked. This will not affect the image display of the head-up display system, but can also effectively reduce the sunlight incident on the head-up display system, protect the head-up display system, and extend the service life of the head-up display system. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings introduced below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0041] Figure 1 It is a structural schematic diagram of a head-up display system in the related art;

[0042] Figure 2 One of the structural schematic diagrams of the head-up display system provided by an embodiment of the present invention;

[0043] Figure 3 One of the principle schematic diagrams of the tunable filter layer provided in an embodiment of the present invention;

[0044] Figure 4 The second schematic diagram of the principle of the tunable filter layer provided by the embodiment of the present invention;

[0045] Figure 5 The third schematic diagram of the principle of the tunable filter layer provided by the embodiment of the present invention;

[0046] Figure 6 One of the structural schematic diagrams of the tunable filter layer provided in an embodiment of the present invention;

[0047] Figure 7 A schematic diagram of the structure of a second electrode provided in an embodiment of the present invention;

[0048] Figure 8 A graph showing the relationship between angle and diffraction efficiency provided by an embodiment of the present invention;

[0049] Fig. 9 A graph showing the relationship between wavelength and diffraction efficiency provided by an embodiment of the present invention;

[0050] Fig.10 The second structural schematic diagram of the tunable filter layer provided in the embodiment of the present invention;

[0051] Fig.11 A second structural diagram of a head-up display system provided by an embodiment of the present invention;

[0052] Fig.12 This is a flow chart of a display control method of a head-up display system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described below with reference to the accompanying drawings and examples. However, the exemplary embodiments can be implemented in various forms and should not be understood as being limited to the embodiments described herein; on the contrary, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concepts of the exemplary embodiments to those skilled in the art. The same figure marks in the figures represent the same or similar structures, and thus their repeated descriptions will be omitted. The words expressing position and direction described in the present invention are all explained using the accompanying drawings as examples, but changes can be made as needed, and the changes made are all included in the scope of protection of the present invention. The drawings of the present invention are only used to illustrate the relative position relationship and do not represent the true proportions.

[0054] HUD technology was first installed on military aircraft, and has gradually penetrated into the automotive field with the development and extension of technology. In addition to replacing instruments and displaying information on various dashboards (such as speed, tire pressure, fuel consumption, speed limit, warnings, etc.), HUD can also display navigation, assisted driving, automatic driving and other information originally displayed on the central control multimedia screen, so that drivers almost don't have to look down when driving, greatly improving driving safety.

[0055] like Figure 1 As shown, the current HUD system usually includes: a display screen 11 and an imaging component 12. The display screen 11 displays images and emits image light to the imaging component 12. The imaging component 12 images the incident light and emits it to the windshield. The windshield then reflects the image to the human eye, and the human eye can view the enlarged virtual image in front of the windshield.

[0056] Due to the reversibility of the optical path, sunlight can converge on the display screen 11 along the optical path of the imaging component 12 at a certain angle, forming a high-energy-density sunlight distribution on the display screen 11. In the summer when the sun is exposed to strong sunlight, the radiation power of the sunlight is relatively large, which will cause the internal temperature of the head-up display system to rise, and it is very likely to burn the display screen and reduce its service life.

[0057] In view of this, an embodiment of the present invention provides a head-up display system, in which a tunable filter layer is arranged on the surface of an optical element, which can pass the outgoing light of the display screen while blocking light of other wavelengths, thereby effectively reducing the sunlight incident on the display screen 11 and extending the service life of the head-up display system.

[0058] Specifically, Figure 2 As shown, the head-up display system provided by the embodiment of the present invention includes: a display screen 11, an imaging component 12, a protective cover 13, a tunable filter layer 14 and a controller 15.

[0059] The display screen 11 is used for image display. The display screen 11 in the head-up display system is usually small in size, and the displayed image needs to be magnified by the imaging component 12 and imaged at a comfortable distance for the human eye.

[0060] The display screen 1 may be a liquid crystal display, a liquid crystal on silicon display or a digital light processing system, which is not limited here.

[0061] Liquid Crystal Display (LCD) is mainly composed of a backlight module and a liquid crystal display panel. The liquid crystal display panel itself does not emit light, and needs to rely on the light source provided by the backlight module to achieve brightness display. The display principle of LCD is to place the liquid crystal between two pieces of conductive glass, and rely on the electric field between the two electrodes to drive the electric field effect of the liquid crystal molecules to distort, so as to control the transmission or shielding function of the backlight source, thereby displaying the image. If a color filter is added, a color image can be displayed. Liquid crystal display technology is mature, and the liquid crystal display screen has a low cost and excellent performance.

[0062] Liquid Crystal on Silicon (LCOS) display technology is a new reflective display technology that organically combines LCD and CMOS integrated circuits. LCOS has many advantages such as high brightness, high resolution, and power saving.

[0063] The core component of the Digital Light Processing (DLP) system is the Digital Micromirror Device (DMD). The DMD surface includes many tiny mirrors, each of which can be driven to deflect individually. By controlling the deflection angle of the DMD, the brightness of the reflected light of each tiny mirror is controlled, thereby generating a display image.

[0064] In the embodiment of the present invention, the display screen 11 emits primary color lights in sequence according to a set timing. In order to achieve full-color display, the display screen 11 usually displays an image composed of a red sub-image, a green sub-image, and a blue sub-image. The switching frequency of the red sub-image, the green sub-image, and the blue sub-image is greater than the frequency that the human eye can recognize, so that the retention efficiency of the human eye can be used to superimpose and synthesize a color image.

[0065] The imaging component 12 is located on the light-emitting side of the display screen 11 , and is used to image the image displayed on the display screen 11 and emit it to the windshield, which is then reflected by the windshield to the human eye.

[0066] The imaging component 12 may include at least one optical lens, which may be a lens or a reflector, and the optical lens is used to image the display image of the display screen.

[0067] In some embodiments, Figure 2 As shown, the imaging component 12 may include a first reflector 121 and a second reflector 122. The outgoing light of the display screen 11 is incident on the first reflector 121, and is reflected by the first reflector 121 toward the second reflector 122. The second reflector 122 reflects the incident light toward the windshield, and finally is reflected by the windshield to the human eye.

[0068] The first reflector 121 and the second reflector 122 need to be reasonably optically designed according to the surface shape of the windshield, and the preconditions such as the position of the human eye and the imaging position. In some embodiments, the first reflector 121 and / or the second reflector 122 can be a free-form reflector, which is not limited here.

[0069] The imaging component uses a curved reflector, which can not only image the display image of the display screen, but also fold the imaging light path, thereby controlling the overall volume of the head-up display system from being too large.

[0070] The protective cover 13 is located between the imaging component 12 and the windshield. Usually, the display screen 11 and the imaging component 12 can be placed in the protective cover, thereby providing dust protection for the display screen 11 and the imaging component 12 .

[0071] The protective cover 13 may be made of a light-transmitting hard material, such as an acrylic plate, etc. The protective cover 13 has good light transmittance and generally has no imaging effect.

[0072] The controller 15 can be located inside the protective cover 13, or can be independently arranged outside the protective cover 13. The controller 15 can be a processing chip, a processor, etc., which is not limited here. The controller 15 can control the display screen and the tunable filter layer at the same time, or the controller 15 can also be used only to control the tunable filter layer, which is not limited here.

[0073] The tunable filter layer 14 is located on any surface of the display screen 11, any optical lens in the imaging component, and the protective cover 13. Figure 2 The tunable light streamer layer 14 is located on the surface of the protective cover 13 as an example. The controller 15 is connected to the display screen 11 and the tunable filter layer 14. The controller 15 determines the wavelength of the current light emitted from the display screen 11 by determining the light emission timing of the display screen, and controls the tunable filter layer 14 to emit the primary color light through the current display screen according to the wavelength of the current light emission, and blocks the light of other wavelengths except the primary color light.

[0074] For example, the display screen 11 can use a projection system. When displaying an image, the projection light source will emit primary color light according to the set timing to modulate the brightness. The modulated light will be emitted to the windshield after being imaged by the imaging component 12, and finally reflected to the human eye by the windshield. Then the display screen 11 can synchronize its light emission timing to the controller 15. The controller 15 determines the wavelength of the current emitted light of the display screen 11 according to the light emission timing, generates a driving electrical signal according to the wavelength, and the tunable filter layer 14 is driven according to the driving electrical signal, so that the current emitted light of the display screen 11 can pass through, while blocking light of other wavelengths. For the incident sunlight, the spectrum of sunlight is relatively wide. Only light with the same wavelength as the current emitted light of the display screen 11 can pass through the imaging component to the display screen 11, while other light is blocked by the tunable filter layer 14. This can effectively reduce the sunlight incident on the display screen 11, thereby avoiding damage to the display screen by sunlight and extending the service life of the head-up display system.

[0075] The tunable filter layer 14 has wave vector selectivity, which includes spectral selectivity and angular selectivity, reflecting the spectral selectivity of the light beam in a specific propagation direction and the angular selectivity of the light beam with a specific wavelength. The tunable filter layer 14 can be adjusted to pass only the light beam with a specific wavelength incident at a specific incident angle, and block the light beams with other wavelengths and other incident angles.

[0076] The wave vector selectivity of the tunable filter layer 14 can be designed according to actual needs, and can reflect light of a specific wavelength incident at a specific incident angle, or transmit light of a specific wavelength incident at a specific incident angle.

[0077] In some embodiments, the tunable filter layer 14 may be disposed on the reflection surface of the first reflector 121, or on the reflection surface of the second reflector 122. In this case, the tunable filter layer 14 may be designed to reflect the primary color light emitted by the current display screen according to the light emission timing of the display screen, and block light of other wavelengths except the primary color light.

[0078] In some embodiments, the tunable filter layer 14 can be disposed on the light emitting surface of the display screen; or, on any side surface of the protective cover. In this case, the tunable filter layer is designed to transmit the primary color light emitted by the current display screen according to the light emitting timing of the display screen, and block light of other wavelengths except the primary color light.

[0079] Specifically, Figure 3 to Figure 5 As shown, the tunable filter layer includes: a substrate 141 , an adjustment mechanism 142 and a tunable medium layer 143 .

[0080] The substrate 141 can be made of a light-transmitting material. Depending on the actual application scenario, the substrate 141 can be made of a hard material or a flexible material. For example, when the tunable filter layer 14 is disposed on the surface of the display screen 11 or the protective cover 13, a hard light-transmitting material can be used; when the tunable filter layer 14 is located on the first reflector 121 or the second reflector 122, since the first reflector 121 or the second reflector 122 has a certain curvature, the substrate 141 of the tunable filter layer can be made of a flexible light-transmitting material so as to better fit the curved surface.

[0081] The adjustment mechanism 142 is located on the substrate 141, and the tunable dielectric layer 143 is connected to the adjustment mechanism 142; the adjustment mechanism can specifically adopt electrodes or motors to generate driving signals by electric control or magnetic control. The tunable dielectric layer 143 can generate a periodic structure under the drive of the driving signal, thereby having wave vector selectivity.

[0082] In a specific implementation, the tunable medium layer 142 may be liquid crystal, charged molecules, magnetic molecules, or other media that can change position, electrical properties, or optical properties in an electric field or a magnetic field, which is not limited here.

[0083] Figure 3 The spectral selection principle of the tunable filter layer is shown in FIG. Figure 3As shown, when red light R, green light G and blue light B enter the tunable filter layer at the same incident angle, if the tunable medium layer 143 is controlled to produce a specific periodic structure to reflect the incident red light R and transmit light of other wavelengths, the red light R can be selected from the incident light. Of course, the tunable filter layer can be designed to transmit the incident red light R (or other specific wavelengths of light) and reflect light of other wavelengths. Figure 3 An example is taken in which red light R (or light of other specific wavelengths) is reflected and light of other wavelengths is transmitted.

[0084] Figure 4 and Figure 5 The angle selection principle of the tunable filter layer is shown, where: Figure 4 To reflect light at a specific incident angle, Figure 5 It transmits light with a specific incident angle. Figure 4 and Figure 5 As shown, when light beam A of the same wavelength is incident on the tunable filter layer at different angles, if the tunable medium layer 143 is controlled to produce a specific periodic structure so that light beam a incident at a specific angle can pass through and light at other incident angles is blocked, then light beam a incident at a specific angle can be selected from the incident light.

[0085] When the wave vector selectivity of the tunable filter layer is applied to the head-up display system, the relative positions of the display screen 11, the imaging component 12 and the protective cover 13 are fixed, so the incident angle of the outgoing light of the display screen 11 when it enters the imaging component 12 and the protective cover 13 is fixed, and this incident angle can be used as the incident angle selected by the tunable filter layer. When the display screen 11 emits three primary color lights in a specific time sequence, specifically when the display screen 11 emits red light, the tunable filter layer 14 is modulated to pass the red light and block the light of other wavelengths; when the display screen 11 emits green light, the tunable filter layer 14 is modulated to pass the green light and block the light of other wavelengths; when the display screen 11 emits blue light, the tunable filter layer 14 is modulated to pass the blue light and block the light of other wavelengths, thereby ensuring that the output light of the display screen 11 is efficiently passed by the tunable filter layer 14, while at the same time the light of other wavelengths is blocked, which will not affect the image display of the head-up display system and can effectively reduce the sunlight incident on the head-up display system, thereby protecting the head-up display system.

[0086] In some embodiments, Figure 6As shown, the substrate may include: a first substrate 141a and a second substrate 141b, the first substrate 141a and the second substrate 141b are arranged opposite to each other and at a certain distance. The adjustment mechanism may include: a first electrode 142a and a second electrode 142b, the first electrode 142a is located on a side of the first substrate 141a facing the second substrate 141b, and the second electrode 142b is located on a side of the second substrate 141b facing the first substrate 141a. The tunable dielectric layer 143 may be a liquid crystal layer, and the liquid crystal layer is located between the first electrode 142a and the second electrode 142b.

[0087] Liquid crystal molecules are birefringent crystals that can flip under the action of an electric field, thereby causing a change in the refractive index. The first electrode 142a and the second electrode 142b located on both sides of the liquid crystal layer are applied with an electric signal according to the light emission timing of the display screen, and an electric field is generated between the first electrode 142a and the second electrode 142b to change the refractive index of the liquid crystal layer, so that the refractive index of the liquid crystal layer changes periodically to form a diffraction grating.

[0088] Specifically, if Figure 7 As shown, at least one of the electrodes located on both sides of the liquid crystal layer can be a dispersed block electrode. Figure 7 The second electrode 142b is a block electrode for illustration. Each block electrode can be individually applied with an electrical signal, thereby generating an electric field between each block electrode and the opposite electrode, thereby controlling the flipping of liquid crystal molecules in different regions, so that the refractive index in each region can be individually controlled.

[0089] When the liquid crystal layer is divided into a plurality of regions and the refractive index between the regions varies periodically, the liquid crystal layer may form a structure similar to a volume Bragg grating, which has a high diffraction efficiency only for light of a specific wavelength incident at a specific incident angle.

[0090] When light enters a volume Bragg grating, it interacts with the interface of the grating. If the light and the grating have a certain angle, the incident light will be diffracted by the grating to different angles, and the diffraction law satisfies: d(sini±sinθ)=mλ, where d represents the grating constant, i represents the incident angle, θ represents the diffraction angle, m represents the diffraction order, and λ represents the wavelength of the incident light. This diffraction condition determines the relationship between the incident angle, diffraction angle and wavelength of the incident light of the grating diffraction.

[0091] Then, when controlling the liquid crystal layer, the electrical signals applied by different electrodes can be controlled according to the incident angle of the light emitted from the display screen, so that the incident light meets the Bragg condition, thereby achieving the maximum diffraction efficiency when the light emitted from the display screen enters the volume Bragg grating.

[0092] like Figure 8 and Fig. 9 As shown in , diffraction gratings are usually wavelength-sensitive and angle-sensitive, and therefore have a better wave vector selection effect. Figure 8 As shown in , the diffraction grating has a high diffraction efficiency only within a small incident angle range Δθ. Fig. 9 As shown in the figure, the diffraction grating has a high diffraction efficiency only within a small wavelength range Δλ. Therefore, the refractive index change of the grating can be controlled according to the angle at which the outgoing light of the display screen is incident on the grating and the wavelength of the current outgoing light of the display screen, thereby changing the grating constant, so that the diffracted light of the grating can continue to propagate along the imaging optical path, while the diffraction efficiency of the incident light at other incident angles and other wavelengths will be reduced, thereby achieving the effect of wave vector selection.

[0093] In a specific implementation, the controller can determine the wavelength of the current output light of the display screen according to the output timing of the display screen, and then calculate the period of the volume Bragg grating according to the wavelength, incident angle and diffraction angle, so as to generate a driving electrical signal for controlling the first electrode and the second electrode, and control the liquid crystal layer to form a volume Bragg grating that can efficiently diffract the output light of the display screen.

[0094] Since the relative positions of the display screen, imaging component, protective cover, and windshield are fixed, the emission angle of the output light of the display screen, the wavelength of the output light, and the optical path in the head-up display system are all fixed. Therefore, the driving electrical signal when the display screen emits the three primary colors of light can be predetermined based on these conditions, and a mapping relationship is formed between the light emission timing of the display screen and the driving electrical signal. When displaying an image, as long as the controller can obtain the light emission timing of the display screen, it can automatically output the driving electrical signal to the first electrode and the second electrode according to the light emission timing, thereby controlling the liquid crystal layer to form a volume Bragg grating that can efficiently diffract the output light of the display screen.

[0095] In some embodiments, Fig.10 As shown, the substrate may include: a first substrate 141a and a second substrate 141b, the first substrate 141a and the second substrate 141b are arranged opposite to each other and at a certain distance. The adjustment mechanism may include: a first electrode 142a and a second electrode 142b, the first electrode 142a is located on the side of the first substrate 141a facing the second substrate 141b, and the second electrode 142b is located on the side of the second substrate 141b facing the first substrate 141a. The tunable dielectric layer may include: a liquid crystal layer 143a and a microstructure layer 143b, the liquid crystal layer 143a is located between the first electrode 142a and the second electrode 142b; the microstructure layer is located between the first electrode 142a and the liquid crystal layer 143a, or between the second electrode 142b and the liquid crystal layer 143a.

[0096] The microstructure layer on the electrode surface is a two-dimensional array composed of multiple sub-wavelength microstructures. These microstructures can be made using micro-nano technology, and their essence constitutes a metasurface. The shape, length, height, azimuth, and arrangement rules of the microstructure of the metasurface can all affect the phase, amplitude, and polarization of the incident light. Therefore, by accurately designing the microstructure of the metasurface, the filtering effect can be achieved.

[0097] The surface of the metasurface is also covered with a liquid crystal layer 143a. When an electrical signal is applied to the first electrode 142a and the second electrode 142b, the refractive index of the liquid crystal layer around the metasurface will change, thereby shifting the resonance wavelength of the metasurface, thereby filtering light of different wavelengths.

[0098] The embodiments of the present invention can utilize this characteristic of the metasurface to form a tunable filter layer. When the light emission timing or the wavelength of the output light of the display screen is determined, a driving signal can be applied to the electrodes on both sides of the liquid crystal layer accordingly to control the refractive index of the liquid crystal layer to change, thereby making the resonant wavelength of the metasurface the wavelength of the output light of the current display screen, thereby achieving an efficient filtering effect.

[0099] The embodiments of the present invention are only used for illustration. In specific implementation, the tunable filter layer may also adopt other optical models. As long as the implementation method can achieve the tunable filtering effect, it falls within the protection scope of the present invention.

[0100] In some embodiments, Fig.11 As shown, the head-up display system can also be provided with a photoelectric sensor 16. The photoelectric sensor 16 needs to be provided in the light output path of the display screen, preferably close to the display screen, and the photoelectric sensor 16 is connected to the controller 15. The photoelectric sensor can detect the wavelength of the output light of the display screen and send the detection structure to the controller 15, so that the controller 15 generates a driving electrical signal for the tunable filter layer according to the detected wavelength, thereby driving the tunable filter layer to pass the light of the currently detected wavelength and block the light of other wavelengths.

[0101] Since the wavelength of the emitted light of the display screen may shift after long-term use, resulting in a certain difference between the central wavelength of the emitted light and the original central wavelength, the wavelength can be detected by the photoelectric sensor 16, and the tunable filter layer can be accurately controlled to filter the light according to the detected wavelength, thereby avoiding the situation where the working wavelength is shifted due to long-term use of the display screen, making it impossible for the tunable filter layer to completely pass the emitted light of the display screen, thereby improving the light efficiency of the head-up display system.

[0102] Based on the same inventive concept, an embodiment of the present invention further provides a display control method of a head-up display system, such as Fig.12 As shown, the display control method of the head-up display system includes:

[0103] S10, the display screen emits primary color lights in sequence according to the set timing;

[0104] S20, the controller determines the light emission timing of the display screen, and generates a driving electrical signal according to the light emission timing;

[0105] S30. The tunable filter layer, driven by the driving electrical signal, passes the primary color light emitted by the current display screen and blocks light of other wavelengths except the primary color light.

[0106] The tunable filter layer has wave vector selectivity. When the display screen emits the three primary colors of light in a specific timing, the tunable filter layer can dynamically pass the output light of the display screen, and light of other wavelengths is blocked. This will not affect the image display of the head-up display system, but can also effectively reduce the sunlight incident on the head-up display system, thereby protecting the head-up display system.

[0107] In some embodiments, the head-up display system also includes a photoelectric sensor, which is connected to the controller. The photoelectric sensor can detect the wavelength of light emitted by the display screen. The controller generates a driving electrical signal based on the wavelength detected by the photoelectric sensor, thereby driving the tunable filter layer to pass the light of the currently detected wavelength and block the light of other wavelengths.

[0108] Whether to set up a photoelectric sensor in the head-up display system can be selected according to actual needs. When a photoelectric sensor is set up in the head-up display system, the photoelectric sensor can detect the wavelength of the light emitted by the display screen, and the controller can calculate the driving electrical signal of the tunable filter layer according to the wavelength, incident angle, and emission angle, so as to control the tunable filter layer to filter the current light emitted by the display screen.

[0109] When the head-up display system is not equipped with a photoelectric sensor, the controller can directly obtain the light emission timing of the display screen. Since the relative position relationship of the display screen, the imaging component, the protective cover, and the windshield are fixed, the emission angle of the output light of the display screen, the wavelength of the output light, and the optical path in the head-up display system are all fixed. Then, the driving electrical signal when the display screen emits the three primary colors of light can be determined in advance based on these conditions, and a mapping relationship is formed between the light emission timing of the display screen and the driving electrical signal. When displaying an image, as long as the controller can obtain the light emission timing of the display screen, it can automatically output the driving electrical signal according to the light emission timing, thereby controlling the tunable filter layer to filter the current output light of the display screen.

[0110] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0111] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A head-up display system, characterized in that: include: A display screen, used for image display; the display screen emits primary color lights in sequence according to a set timing; An imaging component, located at the light-emitting side of the display screen, used to image the image displayed on the display screen and then emit it to the windshield of the vehicle; the imaging component includes at least one optical lens, and the optical lens is used to image the image displayed on the display screen; A protective cover, located between the imaging assembly and the windshield, for protecting the display screen and the imaging assembly; A tunable filter layer is located on any surface of the display screen, the optical lens and the protective cover, and is used to block light of other wavelengths except the primary color light through the primary color light currently emitted by the display screen according to the light emission timing of the display screen; A controller is electrically connected to the display screen and the tunable filter layer; the controller is used to determine the light emission timing of the display screen, and control the display screen to emit primary color lights in sequence according to the light emission timing, and control the tunable filter layer to block light of other wavelengths except the primary color light through the primary color light currently emitted by the display screen.

2. The head-up display system according to claim 1, characterized in that: The imaging assembly includes a first reflector and a second reflector; The outgoing light of the display screen is incident on the first reflector, and is reflected by the first reflector toward the second reflector. The second reflector reflects the incident light toward the protective cover, and the incident light passes through the protective cover and is incident on the windshield.

3. The head-up display system according to claim 2, characterized in that: The tunable filter layer is located on the reflection surface of the first reflector; or the tunable filter layer is located on the reflection surface of the second reflector; The tunable filter layer is used to reflect the primary color light currently emitted by the display screen according to the light emission timing of the display screen, and block light of other wavelengths except the primary color light.

4. The head-up display system according to claim 2, characterized in that: The tunable filter layer is located on the light emitting surface of the display screen; or, the tunable filter layer is located on any side surface of the protective cover; The tunable filter layer is used to transmit the primary color light currently emitted by the display screen according to the light emission timing of the display screen, and block light of other wavelengths except the primary color light.

5. The head-up display system according to claim 3 or 4, characterized in that: The tunable filter layer comprises: substrate; an adjustment mechanism, located on the base; The tunable dielectric layer is connected to the regulating mechanism; when an electrical signal is applied to the regulating mechanism, the tunable dielectric layer generates a periodic structure and has wave vector selectivity.

6. The head-up display system according to claim 5, characterized in that: The substrate comprises: a first substrate and a second substrate, wherein the first substrate and the second substrate are arranged opposite to each other; The adjustment mechanism comprises: a first electrode and a second electrode, the first electrode being located on a side of the first substrate facing the second substrate, and the second electrode being located on a side of the second substrate facing the first substrate; The tunable medium layer includes: a liquid crystal layer located between the first electrode and the second electrode; The first electrode and the second electrode are used to apply electrical signals according to the light emission timing of the display screen, so that an electric field is generated between the first electrode and the second electrode to change the refractive index of the liquid crystal layer, so that the refractive index of the liquid crystal layer changes periodically to form a diffraction grating.

7. The head-up display system according to claim 5, characterized in that: The substrate comprises: a first substrate and a second substrate, wherein the first substrate and the second substrate are arranged opposite to each other; The adjustment mechanism comprises: a first electrode and a second electrode, the first electrode being located on a side of the first substrate facing the second substrate, and the second electrode being located on a side of the second substrate facing the first substrate; The tunable medium layer includes: a liquid crystal layer located between the first electrode and the second electrode; and a microstructure layer located between the first electrode and the liquid crystal layer, or between the second electrode and the liquid crystal layer; The first electrode and the second electrode are used to be applied with electrical signals according to the light emission timing of the display screen, so that the refractive index of the liquid crystal layer changes and resonates with the super surface formed by the microstructure layer.

8. The head-up display system according to any one of claims 1 to 4, characterized in that: The head-up display system further includes: A photoelectric sensor, electrically connected to the controller, the photoelectric sensor is located in the optical path of the outgoing light of the display screen, and is used to detect the wavelength of the outgoing light of the display screen; The controller controls the tunable filter layer to pass the light of the currently detected wavelength and block the light of other wavelengths according to the wavelength detected by the photoelectric sensor.

9. A display control method for a head-up display system, characterized in that: include: The display screen emits primary color lights in sequence according to the set timing; The controller determines the light emission timing of the display screen and generates a driving electrical signal according to the light emission timing; Driven by the driving electrical signal, the tunable filter layer passes the primary color light currently emitted by the display screen and blocks light of other wavelengths except the primary color light.

10. The method according to claim 9, characterized in that The head-up display system is also provided with a photoelectric sensor; the method further comprises: The photoelectric sensor detects the wavelength of the light currently emitted from the display screen; The controller generates a driving electrical signal according to the wavelength detected by the photoelectric sensor; The tunable filter layer, driven by the driving electrical signal, passes the light of the currently detected wavelength and blocks the light of other wavelengths.

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