Shading film suitable for head-up display and head-up display

Abstract

The invention discloses a light-shielding film suitable for head-up display and a head-up display, the light-shielding film comprises a plurality of light-shielding grids, the plurality of light-shielding grids are arranged at intervals and configured to transmit first-direction light propagating from a front view of a vehicle along a first direction, and block at least part of second-direction light propagating from an external light source along a second direction; the light in the second direction can reach the display screen of the head-up display without being blocked by the shading film; the extension direction of at least one of the plurality of shading grids is parallel to the first direction, and the extension directions of at least two shading grids are not parallel to each other; wherein the first direction intersects with the second direction. The shading grids are arranged in the shading film at intervals, so that sunlight is prevented from flowing backwards to the display screen, the service life of the display screen is prolonged, and the virtual imaging effect of the shading film is improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to display technology and particularly to a shading film suitable for a head-up display. Background Art

[0002] The head-up display (HUD) generates a virtual image in front of the driver of the vehicle and provides various information to the driver by displaying information in the virtual image. The external light source focuses on the HUD display screen, and the backflow of sunlight causes the display screen to be too hot, affecting product performance and life, and reducing the imaging effect of the virtual image.

[0003] At present, HUD-related materials have been continuously developing high-temperature resistance, but it is difficult to achieve technological breakthroughs in a short period of time. Summary of the invention

[0004] Based on this, the present invention provides a shading film suitable for head-up display and head-up display, so as to reduce the influence of sunlight backflow on the display screen, effectively prevent the temperature of the display screen from rising sharply, extend the service life of the display screen and improve the imaging effect of virtual images.

[0005] In a first aspect, the present invention provides a shading film suitable for a head-up display, comprising:

[0006] A plurality of light shielding grilles, the plurality of light shielding grilles are arranged at intervals and are configured to transmit first-direction light propagating in a first direction from a front field of view of the vehicle and block at least a portion of second-direction light propagating in a second direction from an external light source; the second-direction light can reach the display screen of the head-up display without being blocked by the light shielding film;

[0007] The extension direction of at least one of the plurality of light-shielding grilles is parallel to the first direction, and the extension directions of at least two light-shielding grilles are not parallel to each other; wherein the first direction intersects with the second direction.

[0008] In a second aspect, the present invention provides a shading film suitable for a head-up display, comprising:

[0009] A plurality of light-shielding grilles, which are arranged at intervals and configured to transmit first-direction light propagating from a front field of view of the vehicle along a first direction and block at least a portion of second-direction light propagating from an external light source along a second direction; the second-direction light can reach the display screen of the head-up display without being blocked by the light-shielding film; wherein the first direction and the second direction intersect;

[0010] It also includes a first area and a second area, the first area is located on the optical path of image light output by the display screen of the head-up display; the second area is located on the optical path of non-image light; the arrangement density of the shading grilles in the first area and the shading grilles in the second area is different.

[0011] In a third aspect, the present invention provides a head-up display, comprising the shading film suitable for head-up display provided in the first aspect or the second aspect.

[0012] Compared with the prior art, the shading film and head-up display provided by the present invention have achieved at least the following beneficial effects: the shading film for head-up display provided by the present invention comprises: a plurality of shading grilles, the plurality of shading grilles are arranged at intervals, and are configured to transmit first-direction light propagating from the front field of view of the vehicle along the first direction, and block at least part of the second-direction light propagating from the external light source along the second direction; the second-direction light can reach the display screen of the head-up display without being blocked by the shading film; at least one of the plurality of shading grilles extends in a direction parallel to the first direction, and at least two of the shading grilles extend in directions that are not parallel to each other; wherein the first direction and the second direction intersect. The first-direction light propagating from the front field of view of the vehicle along the first direction is transmitted to ensure a clear field of view observed by the user, and at least part of the second-direction light propagating from the external light source along the second direction is blocked, so as to reduce the influence of the sunlight backflow phenomenon on the display screen, effectively prevent the temperature of the display screen from rising sharply, thereby extending the service life of the display screen and improving the imaging effect of the virtual image. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram of a light-shielding film provided by an embodiment of the present invention applied to a head-up display;

[0014] Figure 2 is a schematic structural diagram of a light-shielding film provided by an embodiment of the present invention;

[0015] Figure 3 is a schematic diagram of another light-shielding film provided by an embodiment of the present invention from a front view perspective;

[0016] Figure 4 is a schematic diagram of another light-shielding film provided by an embodiment of the present invention from a front view perspective;

[0017] Figure 5 is a schematic structural diagram of another light-shielding film provided by an embodiment of the present invention;

[0018] Figure 6 is a schematic top view of another light shielding film provided by an embodiment of the present invention;

[0019] Figure 7 is a top view schematic diagram of another driving electrode of a light shielding film provided by an embodiment of the present invention;

[0020] Figure 8 is a top view schematic diagram of another driving electrode of a light shielding film provided by an embodiment of the present invention;

[0021] Fig. 9 is a top view schematic diagram of another driving electrode of a light shielding film provided by an embodiment of the present invention;

[0022] Fig.10 is a partially enlarged schematic diagram of a light shielding film provided by an embodiment of the present invention;

[0023] Fig.11 is a schematic diagram of a field of view of a user viewing a shading film provided by an embodiment of the present invention;

[0024] Fig.12 is a schematic diagram of a field of view of a user viewing a shading film provided by an embodiment of the present invention;

[0025] Fig.13 is a schematic diagram of calculating the transmittance of a light-shielding film provided by an embodiment of the present invention;

[0026] Fig.14 is a schematic diagram of another light-shielding film provided by an embodiment of the present invention from a front view perspective;

[0027] Fig.15 is a schematic diagram of another light-shielding film provided by an embodiment of the present invention from a front view perspective;

[0028] Fig.16 is a schematic structural diagram of another light-shielding film provided by an embodiment of the present invention;

[0029] Fig.17 It is a schematic diagram of another shading film provided by an embodiment of the present invention from a front view perspective. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0031] Based on one or more of the above technical problems, an embodiment of the present invention provides a shading film suitable for head-up display. Figure 1 is a schematic diagram of a light-shielding film provided by an embodiment of the present invention applied to a head-up display, Figure 2 is a schematic diagram of the structure of a light shielding film provided by an embodiment of the present invention, with reference to Figure 1-Figure 2The shading film 20 for head-up display provided by the embodiment of the present invention includes a plurality of shading grilles 21, the plurality of shading grilles 21 are arranged at intervals, the extension direction of at least one of the plurality of shading grilles 21 is parallel to the first direction a, and the extension directions of at least two shading grilles 21 are not parallel to each other. In other words, the shading grilles 21 are not completely parallel. The shading grilles 21 are configured to transmit the first direction light S1 propagating from the front field of the vehicle along the first direction a, and block at least part of the second direction light S2 propagating from the external light source along the second direction b. The second direction light S2 can reach the display screen of the head-up display without being blocked by the shading film 20.

[0032] refer to Figure 1 and Figure 2 The head-up display HUD can be a windshield-type head-up display (W-HUD), an augmented reality head-up display (AR-HUD), etc. The display screen 30 in the head-up display HUD is used to emit a virtual image of the head-up display. The image light S3 emitted by the display screen 30 reaches the windshield G from the bottom of the windshield G, and reaches the user's field of view after being reflected by the windshield G to form a virtual image. Among them, the display screen 30 is an image generation unit (Picture Generation Unit, PGU), which can use a liquid crystal display panel, an organic or inorganic light-emitting display panel or a projector, etc., to provide a virtual image. In vehicle-mounted applications, the displayed content may include dashboard information, navigation information, lane indicators, construction indicators, accident indicators, and pedestrian detection indicator information.

[0033] The first direction a may be parallel to the horizontal direction X, or may have a certain first angle with the horizontal direction X, and the first angle is an acute angle, for example, the angle range is -60° to 60°. The first direction light S1 refers to the light within the angle range of the first angle. The shading film 20 may be installed on the windshield G of a vehicle (such as a car), and a plurality of shading grilles 21 arranged at intervals are arranged in the shading film 20, and the material may be a shading material with light absorption or light reflection function, such as polyester film, polypropylene film, metal film, etc. The extension directions of the plurality of shading grilles 21 are not completely parallel, but are all within the angle range between the first direction a and the horizontal direction. Such an arrangement can ensure that at least part of the first direction light S1 passes through the windshield G and the shading film 20 from the front field of view of the vehicle to the user's field of view. The first direction light S1 includes but is not limited to the light reflected by surrounding buildings and pedestrians, or the light emitted by the headlights of the opposite vehicle, etc.

[0034] The second direction b can be parallel to the vertical direction Z, or there can be a certain second angle between the second direction b and the vertical direction Z, and the second angle is an acute angle, for example, the angle range is -30° to 30°. The first direction a and the second direction b intersect. The second direction light S2 refers to the light within the angle range of the second angle. The image light S3 reaches the windshield G from the bottom of the windshield G and is reflected to the user's eyes by the windshield G. Without the obstruction of the shading film 20, as Figure 1 As shown by the middle dotted line, the second directional light S2 may reach the display screen 30 of the head-up display HUD from above the windshield G along the reverse direction of the image light S3, causing damage to the display screen 20. For example, vertically incident sunlight at noon.

[0035] Among them, Figure 1 and attached Figure 2 The “×” in the figure indicates that a light shielding film 20 is provided on the optical path of the second directional light S2, and at least a part of the second directional light S2 cannot pass through. Specifically, since the extension direction of the light shielding grille 21 is not completely parallel, and the extension direction intersects with the second direction b, at least a part of the second directional light S2 can be shielded, so that it cannot be incident on the display screen 30, thereby avoiding the harm of the display screen 30 heating up, extending the service life of the display screen 30, and ensuring the HUD virtual imaging display effect.

[0036] Figure 3 is a schematic diagram of another shading film provided by an embodiment of the present invention from a front view perspective, Figure 4 is a schematic diagram of another shading film provided by an embodiment of the present invention from a front view. Figure 3 and Figure 4 The light shielding film 20 further includes a first region M1 and a second region M2. The present application differentiates the structures of the light shielding grille 21 in the first region M1 and the light shielding grille 21 in the second region M2. Figure 1 The light shielding film 20 is disposed on the vehicle windshield G, the first area M1 is located on the optical path of the image light S3 outputted by the display screen 30 of the head-up display HUD, and the second area M2 is located on the optical path of the non-image light. The non-image light may be the first directional light S and the second directional light S2.

[0037] Please refer to Figure 2 and Figure 3, at least part of the shading grille 21 in the first area M1 and the shading grille 21 in the second area M2 have different extension directions. In the embodiment of the present application, the first area M1 is usually located in the area of ​​the windshield G close to the driver, and the extension direction of at least part of the shading grille 21 in the first area M1 can be set to be parallel to the driver's line of sight, which can block at least part of the second direction light S2, while reducing the shading of the first direction light S1 by the shading grille 21 in the first area M1, thereby improving the light transmittance of this area. The extension direction of the shading grille 21 in the second area M2 can be reasonably adjusted according to the viewing effect of the driver, and is not limited here.

[0038] refer to Figure 4 , the arrangement density of the light shielding grille 21 in the first area M1 and the light shielding grille 21 in the second area M2 is different. In the embodiment of the present application, the arrangement density of the light shielding grille 21 in the first area M1 can be set to be greater than the arrangement density of the light shielding grille 21 in the second area M2, so as to block more second direction light S2 from flowing back through the first area M1 to the display screen 30. A small amount of light shielding grille 21 is set in the second area M2 where virtual display is not required, which helps to improve the light transmittance of the area and improve the clarity of the driver's field of vision.

[0039] In some embodiments, reference Figure 4 , at least part of the light shielding grille 21 in the first area M1 and the light shielding grille 21 in the second area M2 extend in different directions, and the light shielding grille 21 in the first area M1 and the light shielding grille 21 in the second area M2 are arranged at different densities. In the embodiment of the present application, it is also possible to comprehensively consider setting at least part of the light shielding grille 21 in the first area M1 to be parallel to the driver's line of sight, and the arrangement density of the light shielding grille 21 in the first area M1 is greater than the arrangement density of the light shielding grille 21 in the second area M2, so as to achieve the effect of the light shielding grille 21 shielding the second direction light S2 while transmitting the first direction light S1.

[0040] It should be noted that the structural design of the shading grille 21 in the first area M1 and the second area M2 needs to take into account the vehicle transmittance requirements stipulated by national standards and most countries in the world. For example, according to traffic regulations, for light incident from the front field of view of the vehicle, it is necessary to ensure that the vehicle's transmittance is greater than or equal to 70%.

[0041] Based on the above embodiments, continue to refer to Figure 1, the angle between the plane where the light shielding film 20 is located and the first direction a is an acute angle. In the first area M1, along the second direction b, at least two light shielding grilles 21 partially intersect. It is also possible to adjust the area and extension direction of at least two light shielding grilles 21 in the first area M1 so that their orthographic projections along the second direction b at least partially intersect, so that the projection spaces of different light shielding grilles 21 in the second direction b are continuous, thereby reducing the second direction light S2 from entering the display screen 30.

[0042] Based on the above embodiments, Figure 2 The light shielding film 20 further includes a transparent resin 22 filling the spaces between the plurality of light shielding grilles 21, and the light shielding grilles 21 are fixed in the transparent resin 22. In the embodiment of the present application, the light shielding grilles 21 are fixedly arranged in the light shielding film 20. When the light shielding film 20 is arranged on the vehicle windshield G, the light shielding grilles 21 transmit a fixed angle range of the first direction light S1 and block a fixed angle range of the second direction S2. The light shielding film 20 has a simple preparation process and is easy to attach.

[0043] Figure 5 Schematic diagram of another light shielding film provided by an embodiment of the present invention. Figure 5 , the light shielding grille 21 is a polar material, such as cellulose resin, hydroxypropyl methylcellulose, etc., and contains polar groups in the molecular structure, has high polarity, and can be well combined with light shielding agents such as carbon black, etc. The specific material is cellulose acetate butyrate, which has excellent flexibility, impact resistance and weather resistance. Driving electrodes 24 are set at both ends of the light shielding grille 21. By adjusting the driving electric field between the driving electrodes 24 at both ends of the light shielding grille 21, the angle and position of the light shielding grille 21 are adjusted to pass the first direction light S1 and block the second direction light S2. In the embodiment of the present application, the light shielding grille 21 is non-fixed, and the driving electrodes 24 are set at the two sections of the light shielding grille 21. By controlling the electric field strength and electric field angle of the driving electrodes 24, the light shielding grille 21 is driven to move, so that its extension direction changes, thereby matching the user's field of view, and can pass the first direction light S1 to the maximum range and block the second direction light S2 to the maximum range, meeting the user's viewing needs.

[0044] Based on the above embodiments, Figure 5, the driving electrode 24 includes a first electrode 24a and a second electrode 24b. The first electrode 24a is located at the first end of the light-shielding grille 21, and the second electrode 24b is located at the second end of the light-shielding grille 21, and a driving electric field is formed between the first electrode 24a and the second electrode 24b. Among them, the first end is the end of the light-shielding grille 21 close to the user, and the second end is the end of the light-shielding grille 21 away from the user. With the first end of the light-shielding grille 21 as a fixed point, the driving electric field is used to drive the light-shielding grille 21 to deflect around the fixed point to a preset angle and position. In an embodiment of the present application, the voltage received by the first electrode 24a is different from the voltage received by the second electrode 24b, and a driving electric field is formed between the two. By adjusting the electric field strength and electric field angle of the driving electric field, the second end of the light-shielding grille 21 can be driven to deflect around its first end, so as to achieve the purpose of adjusting the extension direction of the light-shielding grille 21.

[0045] Based on the above embodiments, Figure 5 The light shielding film 20 further includes a first base film 20a and a second base film 20b, a plurality of light shielding grids 21 are located between the first base film 20a and the second base film 20b, a first electrode 24a is located on the first base film 20a, and a second electrode 24b is located on the second base film 20b. The materials of the first base film 20a and the second base film 20b include, but are not limited to, polyethylene, polypropylene, polyester, etc.

[0046] A feasible implementation method is shown in FIG. Figure 5 , a transparent fluid material, such as silicone oil, is filled between the first base film 20a and the second base film 20b. In the embodiment of the present application, the second end of the light shielding grille 21 is fixed on the second base film 20b, and the first end of the light shielding grille 21 is not fixed. The first end of the light shielding grille 21 can move around its second end in the transparent fluid material under the action of the driving motor 24. When there is no driving electric field, the transparent fluid material can also play a role in supporting the light shielding grille 21 to keep it at a certain position and angle.

[0047] A feasible implementation method is shown in FIG. Figure 5, there is a closed space between the first base film 20a and the second base film 20b, the first end of the light-shielding grille 21 is fixed on the first base film 20a, and the second end of the light-shielding grille 21 is supported by a transparent material (not shown in the figure). In the embodiment of the present application, gas can be filled between the first base film 20a and the second base film 20b to reduce the movement resistance of the light-shielding grille 21 and improve the displacement accuracy of the light-shielding grille 21. The fixing method of the second end of the light-shielding grille 21 includes but is not limited to mechanical fixing, adhesive fixing, electromagnetic field fixing, microstructure fixing, etc. Transparent materials include but are not limited to polymethyl methacrylate (Poly (methyl methacrylate, PMMA), polycarbonate (Polycarbonate, PC), glass fiber reinforced polyester resin, fluorinated ethylene propylene copolymer (Fluorinated ethylene propylene, FEP), polyvinyl fluoride (Poly (vinyl formal, PVF), etc.

[0048] Figure 6 is a schematic top view of another light shielding film provided by an embodiment of the present invention, Figure 7 is a schematic diagram of a top view of a driving electrode of another light shielding film provided by an embodiment of the present invention, wherein: Figure 7 Only the second electrode 24b is shown, and the first electrode 24a is not shown, receiving the same or different driving voltages. In the embodiment of the present application, the shading grid 21 can be designed as a segmented type, and each shading grid 21 is more easily deflected under the driving electric field, and regional adjustment can be performed at the same time.

[0049] A feasible embodiment mode, refer to Figure 1 , Figure 5-Figure 7 , the first ends of the multiple light-shielding grilles 21 are connected to the same first electrode 24a, and the second ends of the multiple light-shielding grilles 21 are connected to different second electrodes 24b. The driving electric fields at both ends of different light-shielding grilles 21 are different. Among them, the first electrode 24a can be a plurality of independent electrodes, but receive the same driving voltage. In an embodiment of the present application, the first electrodes 24a at the first ends of the multiple light-shielding grilles 21 have the same driving voltage, and the driving electric fields at both ends of the multiple light-shielding grilles 21 are adjusted by individually controlling the driving voltages of the second electrodes 24b at the second ends of the multiple light-shielding grilles 21, so as to achieve the purpose of individually regulating the positions and angles of the multiple light-shielding grilles 21, which is conducive to realizing precise control of the extension direction of each light-shielding grille 21, so as to transmit as much light S1 in the first direction as possible, improve the transmittance, block the light S2 in the second direction, and avoid sunlight backflow.

[0050] A feasible embodiment mode, refer to Figure 1 , Figure 5-Figure 7, the first ends of the multiple light-shielding grilles 21 are connected to different first electrodes 24a, the second ends of the multiple light-shielding grilles 21 are connected to different second electrodes 24b, and the driving electric fields at the two ends of the multiple light-shielding grilles 21 are different. In the embodiment of the present application, the first electrodes 24a at the first ends of the multiple light-shielding grilles 21 are independent of each other, and the second electrodes 24b at the second ends of the multiple light-shielding grilles 21 are independent of each other, and a preset driving voltage can be applied to the first electrode 24a at the first end and the second electrode 24b at the second end of each light-shielding grille 21. For example, in some applications, the light-shielding film 20 can be divided into any area, and the moving position and angle of the light-shielding grille 21 in the divided area can be individually adjusted to achieve precise control of the extension direction of each light-shielding grille 21 in any area.

[0051] Figure 8 is a schematic diagram of a top view of a driving electrode of another light shielding film provided by an embodiment of the present invention, wherein: Figure 8 Only the second electrode 24b is shown. A feasible embodiment mode, refer to Figure 1 , Figure 5 , Figure 6 and Figure 8 , multiple light shielding grilles 21 are arranged in an array in the light shielding film 20. In the same row or column, the first ends of the multiple light shielding grilles 21 are connected to the same first electrode 24a, and the second ends are connected to the same second electrode 24b, and the driving electric fields at both ends of the multiple light shielding grilles 21 are the same. Figure 8 Taking the second electrodes 24b corresponding to the light-shielding grilles 21 in the X1th row, the X2th row, and the X3th row along the X direction as an example, in the same row, the first ends of multiple light-shielding grilles 21 are connected to the same first electrode 24a, and the second ends are connected to the same second electrode 24b. The driving voltage received by the second electrode 24b in the X1th row is V1, the driving voltage received by the second electrode 24b in the X2th row is V2, and the driving voltage received by the second electrode 24b in the X3th row is V3, and V1, V2, and V3 are independent of each other. Among them, the first electrodes 24a corresponding to the X1th row, the X2th row, and the X3th row can be grounded, or the driving voltage received is V0, V0≠0V. In this way, the extension direction of the light-shielding grilles 21 in the same row or the same column can be uniformly controlled, the first direction light S1 with the same incident angle is transmitted, and the second direction light S2 with the same incident angle is blocked. At the same time, the difficulty of individually controlling the deflection of the light-shielding grilles 21 can be reduced, and the difficulty of preparation can be reduced.

[0052] For example, when the sunlight is strongest at noon, the extension direction of the shading grilles 21 in the same row is controlled to deflect to block the vertically incident second directional light S2, thereby reducing the risk of screen burn-in on the display screen 30 caused by strong light.

[0053] Based on the above embodiments, Figure 6The light shielding grille 21 is designed to be segmented, and the light shielding grilles 21 in different rows are arranged in a staggered manner. In this way, the size of the light shielding grille 21 can be reduced. On the one hand, the gap for the transmission of the first direction light S1 can be increased, and the transmittance can be improved. On the other hand, due to the staggered arrangement, along the incident direction of the second direction light S2, the projection area of ​​the light shielding grille 21 on the light shielding film 20 is still relatively large, so that the second direction light S2 can be shielded.

[0054] Fig. 9 is a schematic diagram of a top view of a driving electrode of another light shielding film provided by an embodiment of the present invention, wherein: Fig. 9 Only the second electrode 24b is shown. A feasible embodiment mode, refer to Figure 1 , Figure 5 , Figure 6 and Fig. 9 , the first ends of the multiple light-shielding grilles 21 are connected to the same first electrode 24a, the second ends of the multiple light-shielding grilles 21 are connected to the same second electrode 24b, and the driving electric fields at both ends of the multiple light-shielding grilles 21 are the same. In the embodiment of the present application, the driving electric fields between the two ends of the multiple light-shielding grilles 21 are the same, such as the first electrode 24a is grounded, and the driving voltage received by the second electrode 24b is V4, which can uniformly control the moving positions and angles of the multiple light-shielding grilles 21 in the light-shielding film 20, and realize the unified control of the extension direction of all the light-shielding grilles 21, which is conducive to reducing the difficulty of preparation. Among them, the multiple light-shielding grilles 21 can also be all the light-shielding grilles 21 in the light-shielding film 20.

[0055] in, Figure 7-Figure 9 In the figure, the link electrode line 24c is a line connecting the driving electrode and the controller.

[0056] Based on the above embodiments, Figure 5-Figure 9 , the extension direction of the second electrode 24b is parallel to the plane where the light shielding film 20 is located, and the length L1 of the second electrode 24b is greater than or equal to 0.2 times the thickness h of the light shielding film 20. That is, L1 ≥ 0.2h. Specifically, in vehicle-mounted applications, considering that the field of vision of different drivers differs by about 10°, the length L1 of the second electrode 24b can be set to 0.2 times the thickness h of the light shielding film 20, so that the area of ​​the second electrode 24b can be increased, the driving electric field can be increased, and the deflection angle of the second end of the light shielding grille 21 can be expanded to meet the field of vision observation needs of different drivers.

[0057] It should be noted that, in order to meet the requirement that the transmittance of the light-shielding film 20 is greater than 70% in practical applications, the structural setting of the light-shielding grille 21 needs to be reasonably adjusted in combination with practical applications.

[0058] Fig.10 is a schematic diagram of a partially enlarged light shielding film provided by an embodiment of the present invention. Figure 1, Figure 2 and Fig.10 , the angle between the plane where the shading film 20 is located and the horizontal direction X is α, the angle between the user's viewing angle S4 and the horizontal direction X is θ, the thickness of the shading film 20 is h, and the grid spacing of the shading grid 21 is S, satisfying the formula:

[0059]

[0060] The value range of α is 30° to 45°, and the value range of θ is 0° to 10°; the first direction a is parallel to the horizontal direction X, or the angle between the first direction a and the horizontal direction X is an acute angle.

[0061] Specifically, Fig.10 Taking the adjacent first shading grille 21-1 and the second shading grille 21-2 as an example, the grille spacing S of the shading grille 21 is the distance between the first ends of the two adjacent shading grilles 21, and the first end is the end close to the user provided in the above embodiment. The user's observation angle S4 forms a field of view FOV, such as Fig.10 As shown in the middle dotted frame, the first directional light S1 within the field of view FOV can reach the user's eyes after passing through the shading film.

[0062] In vehicle applications, the shading film 20 is disposed on the windshield. Usually, the angle α between the windshield and the horizontal direction X is in the range of 30° to 45°, referred to as the inclination angle of the windshield. The angle θ between the viewing angle S4 and the horizontal direction X is in the range of 0° to 10°. After the thickness h of the shading film 20 is determined, the grid spacing S of the shading grid 21 can be calculated by the above formula.

[0063] refer to Fig.10 , calculated from the geometric relationship, when the angle between the second directional light S2 and the vertical direction Z is less than 30°, such as the sunlight from 11 to 14 o'clock during the day, the light is strong, and the second directional light S2 in this time period can be blocked by the second light-shielding grille 21-2 and cannot enter the display screen. When the angle between the second directional light S2 and the vertical direction Z is greater than or equal to 30°, such as the sunlight from 8 to 11 o'clock during the day, the second directional light S2 in this time period can pass through the grille spacing S, and the sunlight during this time period is usually weak. In the case of comprehensively considering the transmittance and the shading rate, this structural setting can meet the design requirements of blocking strong external light from entering the display screen 20.

[0064] Fig.11 is a schematic diagram of a user's field of view when viewing a shading film provided by an embodiment of the present invention, Fig.12 is a schematic diagram of a user's field of view of a shading film provided by an embodiment of the present invention, wherein: Fig.12 Figure (a) is a schematic diagram of the shading grilles 21 being parallel to each other. Fig.12Figure (a) is a schematic diagram of a non-parallel shading grille 21, and the thickness of the shading grille 21 is h=0.1 mm.

[0065] Exemplary, reference Fig.10 According to the calculation formula of the above-mentioned grid spacing S, with the thickness of the shading film 20 h=0.1mm, the value range of α is 30°~45°, and the value range of θ is 0~10°, the average spacing of the grid spacing S in the field of view FOV is calculated to be 0.13mm, and the minimum spacing is 0.1mm.

[0066] Further, refer to Fig.10 , the thickness of the light shielding grille 21 is set to be greater than or equal to 0.2 times the grille length of the light shielding grille 21. The grille length refers to the length of the light shielding grille 21 in the extension direction, and can also be understood as the length from the first end to the second end of the light shielding grille 21 provided in the above embodiment. Combined with material mechanics statistics, when the thickness of the material is 20% of the length, the stability of the structure can be increased.

[0067] In the embodiment of the present application, the thickness of the light shielding grille 21 affects the transmittance T by the calculation formula: T = grille thickness / grille spacing. For example, the thickness of the light shielding grille 21 is set to be about 0.01 mm, the grille length is about 0.05 mm, the minimum spacing of the grille spacing S is 0.1 mm, and the maximum loss of T is about 10%, which meets the market application requirements.

[0068] Based on the above embodiments, continue to refer to Fig.10 , the grille spacing S of the shading grille 21 is set to be less than or equal to 1.3 times the thickness h of the shading film 20. That is, S≤1.3h. In the embodiment of the present application, according to the value range of the angle α between the windshield and the horizontal direction being 30° to 45°, when the average value of the grille spacing S is 1.3 times the thickness h of the shading film 20, the vertical sunlight (≤30°) can be completely shielded. In actual use, the grille spacing S can be appropriately increased or decreased to meet different shading and transmittance requirements.

[0069] Further, refer to Fig.11 Considering the transmittance attenuation caused by the viewing angle deviation, for the convenience of calculation, it is assumed that the shading grille 21 is placed in parallel (the transmittance attenuation amplitude is larger than the actual one). According to the inclination angle of the car windshield on the market is 30°~45°, the driver's height is 160cm~180cm, and the front and rear amplitude of the driver's seat is 30cm, the viewing angle fluctuates by about 6°~10°, and the maximum angle is 10°.

[0070] refer to Fig.12, the maximum transmittance attenuation is calculated to be (L2 / L1-1)*100%=18%, and the comprehensive limit loss is about 26%, which is less than 30%, meeting the market requirement for a transmittance greater than 70%.

[0071] Based on the above embodiments, Figure 2-Figure 6 The light-shielding grid 21 is a periodically arranged grating structure, which is conducive to reducing the difficulty of the manufacturing process, uniformly transmitting the first direction light S1, and uniformly blocking the second direction light S2.

[0072] Fig.13 FIG. 1 is a schematic diagram of a front viewing angle interface of another shading film provided by an embodiment of the present invention. Based on the above embodiment, Fig.13 In the cross section parallel to the plane where the shading grille 21 is located, the cross section of the shading grille 21 is any one of a strip, a honeycomb and a grid. In the embodiment of the present application, considering that the driver's field of vision is at a certain angle when observing at angles other than the horizontal direction, if a straight grille is used, the field of vision in the up and down oblique direction may become narrower. When the field of vision in the up and down oblique direction is required to be higher, the shading grille 21 can be made into a honeycomb or grid shape, and the left and right directions are also compensated. At the same time, the honeycomb shape is a stable structure and is more convenient for process manufacturing.

[0073] Optional, reference Fig.13 When the cross-sectional shape of the light shielding grille 21 is a honeycomb or grid shape, a plurality of light shielding grilles 21 are connected. In this way, the light shielding grilles 21 support each other, which is conducive to the stability of the structure of the light shielding grille 21.

[0074] Based on the same inventive concept, the embodiment of the present application further provides a shading film 20 suitable for head-up display. Fig.14 is a schematic diagram of another shading film provided by an embodiment of the present invention from a front view perspective, Fig.15 is a schematic diagram of another shading film provided by an embodiment of the present invention from a front view perspective, Fig.16 is a schematic diagram of the structure of another light shielding film provided by an embodiment of the present invention, and further reference is made to Figure 1 , Figure 14-16The light shielding film 20 includes a plurality of light shielding grilles 21 arranged at intervals, which are configured to transmit the first direction light S1 propagating from the front field of the vehicle along the first direction a, and block at least part of the second direction light S2 propagating from the external light source along the second direction b; the second direction light S2 can reach the display screen 30 of the head-up display HUD without being blocked by the light shielding film 20; wherein the first direction a and the second direction b intersect. The light shielding film 20 also includes a first area M1 and a second area M2, the first area M1 is located on the optical path of the image light S3 output by the display screen 30 of the head-up display HUD, and the second area M2 is located on the optical path of the non-image light. The arrangement density of the light shielding grilles 21 in the first area M1 and the light shielding grilles 21 in the second area M2 are different. In the embodiment of the present application, the arrangement density of the light shielding grilles 21 in the first area M1 can be set to be greater than the arrangement density of the light shielding grilles 21 in the second area M2, so as to block more second direction light S2 and prevent the second direction light S2 from entering the display screen 30 of the head-up display, thereby reducing the temperature rise of the display screen 30.

[0075] It should be noted that Figure 14-16 The explanations of the first directional light S1, the second directional light S2, the first area M1, and the second area M2 refer to the above embodiments, and thus will not be further described here.

[0076] Based on the above embodiments, continue to refer to Fig.16 , the extension direction of at least one of the plurality of light-shielding grilles 21 is parallel to the first direction a, and the extension directions of at least two light-shielding grilles 21 are parallel. In the embodiment of the present application, two adjacent light-shielding grilles 21 may be arranged to be parallel to each other, so as to reduce the difficulty of preparation while transmitting at least a portion of the first direction light S1 and shielding at least a portion of the second direction light S2.

[0077] Based on the same inventive concept, the embodiment of the present application further provides a head-up display, including the shading film 20 for head-up display provided in the above embodiment, and further referring to Figure 1 The head-up display HUD further includes at least one dimming element 40 and a windshield G. The dimming element 40 is located on the optical path of the image light S3 emitted from the display screen 30. The windshield G is located on the transmission optical path of the image light S3 adjusted by the dimming element 40, and is used to reflect the image light S3 to the user observation area. The shading film 20 is located in the windshield or on one side surface thereof.

[0078] In the embodiments of this application, continue to refer to Figure 1, at least one light modulator 40 includes a corrective mirror 41 and a concave mirror 42. The corrective mirror 41 can be a plane reflector for reflecting the image light S3. The concave mirror 42 is used to converge and reflect the image light S3 to the windshield G. In the absence of the shading film 20, the second directional light S2 can pass through the top of the windshield G in the reverse direction of the image light S3, and be reflected to the display screen 30 by the concave mirror 42 and the corrective mirror 41, causing the temperature to rise and damage the display screen 30. The shading film 20 provided in the present application can be attached to the inner side of the windshield G, or be set in the interlayer of the windshield G. The gap between the shading grille 21 in the shading film 20 can pass at least part of the first directional light S1 to the user observation area, and the shading grille 21 can block at least part of the second directional light S2 from entering the display screen 30.

[0079] It should be noted that the shading film 20 is installed in the windshield of the vehicle and also has the beneficial effects of the shading film in the above embodiment. The similarities can be understood by referring to the above explanation of the shading film and will not be repeated below.

[0080] Based on the above embodiments, continue to refer to Figure 2 , the extension directions of the plurality of shading grilles 21 are arranged to converge in the observation area. In the embodiment of the present application, the extension directions of all the shading grilles 21 can be converged in the movement range of the driver's eyes based on the movement range of the driver's eyes, so that the extension direction of the shading grilles 21 is parallel to the driver's line of sight, and the driver will not see the shading grilles 21 during driving, and has a clear field of vision.

[0081] Based on the above embodiments, continue to refer to Figure 5 , the light shielding grille 21 is made of polar material, driving electrodes 24 are arranged at both ends of the light shielding grille 21, and an eyeball positioning device and at least one processor (not shown in the figure) are also included, and the eyeball positioning device is used to obtain the position information of the user's eyeball. At least one processor is configured to adjust the driving electric field between the driving electrodes 24 at both ends of the light shielding grille 21 based on the position information of the eyeball, and adjust the angle and position of the light shielding grille 21 to pass the first direction light S1 and block the second direction light S2. The eyeball positioning device can be set on the sub-windshield, and the processor can be a calculation control unit, which can be one or more chips or circuit bodies with calculation, storage, and information transmission functions such as a central processing unit (CPU), a graphics processing unit (GPU), a field programmable gate array (FPGA), etc. Its function is to receive information, calculate and analyze and send signals, and control devices such as driving electrodes.

[0082] In the embodiment of the present application, in the vehicle application, when the driver is driving the vehicle, the eyeball positioning device can also be used to obtain the position information of the driver's eyeball in real time. The processor determines the driver's field of vision based on the driver's eyeball position information and adjusts the driving electric field between the driving electrodes 24 at both ends of the light shielding grille 21. Under the action of the driving electric field, the second end of the light shielding grille 21 deflects around the first end to an angle and position corresponding to the eyeball position information. In the state, the extension direction of the light shielding grille 21 converges at the driver's eyeball position, so as to achieve the purpose of transmitting more first direction light S1 and blocking more second direction light S2, thereby meeting the viewing needs of the driver in different field of vision.

[0083] It should be noted that the beneficial effects of the driving electrodes 24 at both ends of the light-shielding film 20 can be understood by referring to the above explanation of the light-shielding film, and will not be repeated below.

[0084] Fig.17 2 is a schematic diagram of another shading film provided by an embodiment of the present invention. Figure 3 , Figure 4 , Fig.14 and Fig.17 The windshield G includes an image display area G1 and a non-image display area G2, and the image display area G1 is located on the optical path of the image light. The image display area G1 refers to the display area of ​​the flat panel display HUD that the driver sees on the windshield G.

[0085] In some embodiments, reference Fig.17 The shading film 20 does not need to cover the entire windshield G, and the shading film 20 is only provided in the image display area G1 of the windshield G. The second direction light S entering the display screen from the image display area G1 is shielded to protect the display screen, reduce the production cost of the shading film 20, and improve the light transmittance of the non-image display area G2.

[0086] In some embodiments, continue to refer to Figure 3 , Figure 4 , Fig.14 The shading film 20 covers the entire windshield G. The shading film 20 includes a first area M1 and a second area M2. The first area M1 is located in the image display area G1, and the second area M2 is located in the non-image display area G2. Considering that the driver has different visual fields for viewing the image display area G1 and the non-image display area G2, the shading grilles 21 of the first area M1 and the second area M2 can be designed differently.

[0087] In some embodiments, at least part of the shading grilles 21 in the first area M1 and the shading grilles 21 in the second area M2 extend in different directions. For example, the extension directions of the multiple shading grilles 21 in the first area M1 and the second area M2 are converged within the moving range of the driver's eyes, so that the extension direction of the shading grilles 21 is parallel to the driver's line of sight, so that the driver cannot see the shading grilles 21 in the first area M1 and the second area M2 during driving, which can improve the clarity of the vehicle's front field of vision.

[0088] In some embodiments, the arrangement density of the shading grilles 21 in the first area M1 and the shading grilles 21 in the second area M2 is different. For example, the arrangement density of the shading grilles 21 in the first area M1 is set to be greater than the arrangement density of the shading grilles 21 in the second area M2, thereby increasing the transmittance of the windshield G and the shading film 20 corresponding to the second area M2.

[0089] It should be noted that when the first region M1 and the second region M2 are designed differently, the requirement that the transmittance is greater than 70% also needs to be taken into consideration.

[0090] In some embodiments, at least part of the shading grilles 21 in the first area M1 and the shading grilles 21 in the second area M2 have different extension directions, and the shading grilles 21 in the first area M1 and the shading grilles 21 in the second area M2 have different arrangement densities. Based on the above embodiments, the extension directions and arrangement densities of the plurality of shading grilles 21 in the first area M1 and the second area M2 are designed differently to achieve the purpose of transmitting the light in front of the vehicle and shielding the light above the vehicle, thereby ensuring the normal driving of the driver and reducing the damage to the display screen caused by light.

[0091] In summary, it can be seen from the above embodiments that the shading film suitable for head-up display and head-up display provided by the embodiments of the present invention at least achieves the following beneficial effects:

[0092] The shading film suitable for head-up display provided by the present invention comprises: a plurality of shading grilles, which are arranged at intervals and configured to transmit first-direction light propagating from the front field of view of the vehicle along the first direction, and block at least part of the second-direction light propagating from the external light source along the second direction; the second-direction light can reach the display screen of the head-up display without being blocked by the shading film; at least one of the plurality of shading grilles extends in a direction parallel to the first direction, and at least two of the shading grilles extend in directions that are not parallel to each other; wherein the first direction and the second direction intersect. The first-direction light propagating from the front field of view of the vehicle along the first direction is transmitted to ensure a clear field of view for the user to observe, and at least part of the second-direction light propagating from the external light source along the second direction is blocked to reduce the influence of the sunlight backflow phenomenon on the display screen, effectively preventing the temperature of the display screen from rising sharply, thereby extending the service life of the display screen and improving the imaging effect of the virtual image.

[0093] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A shading film suitable for head-up display, characterized in that: include: a plurality of light-shielding grilles, the plurality of light-shielding grilles being arranged at intervals and configured to transmit first-direction light propagating from a front field of view of the vehicle along a first direction and to block at least a portion of second-direction light propagating from an external light source along a second direction; the second-direction light being able to reach a display screen of a head-up display without being blocked by the light-shielding film; An extension direction of at least one of the plurality of shading grilles is parallel to the first direction, and extension directions of at least two of the shading grilles are not parallel to each other; wherein the first direction intersects with the second direction.

2. The light-shielding film according to claim 1, characterized in that: The head-up display further comprises a first region and a second region, wherein the first region is located on a light path of image light outputted by a display screen of the head-up display; and the second region is located on a light path of non-image light; At least part of the shading grilles in the first area and the shading grilles in the second area extend in different directions; and / or the shading grilles in the first area and the shading grilles in the second area have different arrangement densities.

3. The light-shielding film according to claim 1, characterized in that: The invention also includes a transparent resin filling spaces between the plurality of light-shielding grilles, wherein the light-shielding grilles are fixed in the transparent resin.

4. The light-shielding film according to claim 1, characterized in that: The shading grid is made of polar material; Driving electrodes are arranged at both ends of the light-shielding grid, and the angle and position of the light-shielding grid are adjusted by adjusting the driving electric field between the driving electrodes at both ends of the light-shielding grid to transmit the first direction light and block the second direction light.

5. The light-shielding film according to claim 4, characterized in that: The driving electrode comprises a first electrode and a second electrode; the first electrode is located at a first end of the light-shielding grid, the second electrode is located at a second end of the light-shielding grid, and a driving electric field is formed between the first electrode and the second electrode; The first end of the light-shielding grille is used as a fixed point, and the driving electric field is used to drive the light-shielding grille to deflect to a preset angle and position around the fixed point.

6. The light-shielding film according to claim 5, characterized in that: The light shielding film further comprises a first base film and a second base film, the plurality of light shielding grids are located between the first base film and the second base film, the first electrode is located on the first base film, and the second electrode is located on the second base film; A transparent fluid material is filled between the first base film and the second base film; or, There is a closed space between the first base film and the second base film, the first end of the light-shielding grille is fixed on the first base film, and the second end of the light-shielding grille is supported by a transparent material.

7. The light-shielding film according to claim 5, characterized in that: The first ends of the plurality of light-shielding grids are connected to the same first electrode, and the second ends of the plurality of light-shielding grids are connected to different second electrodes; The driving electric fields at the two ends of the different light-shielding grilles are different.

8. The light-shielding film according to claim 5, characterized in that: A plurality of the light-shielding grilles are arranged in an array within the light-shielding film; In the same row or column, the first ends of the plurality of light-shielding grids are connected to the same first electrode, and the second ends are connected to the same second electrode, and the driving electric fields at both ends of the plurality of light-shielding grids are the same.

9. The light-shielding film according to claim 8, characterized in that: The shading grids in different rows are arranged in a staggered manner.

10. The light-shielding film according to claim 5, characterized in that: The first ends of the plurality of light-shielding grids are connected to different first electrodes, the second ends of the plurality of light-shielding grids are connected to different second electrodes, and the driving electric fields at the two ends of the plurality of light-shielding grids are different.

11. The light-shielding film according to claim 5, characterized in that: The first ends of the plurality of light-shielding grids are connected to the same first electrode, the second ends of the plurality of light-shielding grids are connected to the same second electrode, and the driving electric fields at both ends of the plurality of light-shielding grids are the same.

12. The light-shielding film according to claim 5, characterized in that: An extension direction of the second electrode is parallel to the plane where the light shielding film is located, and a length of the second electrode is greater than or equal to 0.2 times the thickness of the light shielding film.

13. The light-shielding film according to claim 2, characterized in that: The angle between the plane where the light shielding film is located and the first direction is an acute angle; In the first region, along the second direction, at least two of the shading grilles partially intersect.

14. The light-shielding film according to claim 1, characterized in that: The angle between the plane where the shading film is located and the horizontal direction is α, the angle between the user's viewing angle and the horizontal direction is θ, the thickness of the shading film is h, and the grid spacing of the shading grid is S, which satisfies the formula: The value range of α is 30° to 45°, and the value range of θ is 0° to 10°; the first direction is parallel to the horizontal direction, or the angle between the first direction and the horizontal direction is an acute angle.

15. The light-shielding film according to claim 1, characterized in that: The thickness of the light-shielding grille is greater than or equal to 0.2 times the grille length of the light-shielding grille.

16. The light-shielding film according to claim 1, characterized in that: The grid spacing of the light-shielding grid is less than or equal to 1.3 times the thickness of the light-shielding film.

17. The light-shielding film according to claim 1, characterized in that: The light-shielding grid is a periodically arranged grating structure.

18. The light-shielding film according to claim 1, characterized in that: In a cross section parallel to the plane where the light-shielding grille is located, the cross-sectional shape of the light-shielding grille is any one of a strip shape, a honeycomb shape and a grid shape.

19. The light-shielding film according to claim 18, characterized in that: When the cross-sectional shape of the light-shielding grille is a honeycomb or a grid, a plurality of the light-shielding grilles are connected.

20. A shading film suitable for head-up display, characterized in that: include: A plurality of light-shielding grilles, the plurality of light-shielding grilles are arranged at intervals and are configured to transmit first-direction light propagating from a front field of view of the vehicle along a first direction and block at least a portion of second-direction light propagating from an external light source along a second direction; the second-direction light can reach a display screen of a head-up display without being blocked by the light-shielding film; wherein the first direction and the second direction intersect; It also includes a first area and a second area, the first area is located on the optical path of image light output by the display screen of the head-up display; the second area is located on the optical path of non-image light; the arrangement density of the shading grilles in the first area and the shading grilles in the second area are different.

21. The light-shielding film according to claim 20, characterized in that: An extension direction of at least one of the plurality of light-shielding grilles is parallel to the first direction, and extension directions of at least two of the light-shielding grilles are parallel.

22. A head-up display, characterized in that: The shading film suitable for head-up display according to any one of claims 1 to 21 further comprises: At least one dimming element is located on the optical path of the image light emitted by the display screen; The windshield is located on the transmission light path of the image light adjusted by the dimming element, and is used to reflect the image light to the user observation area; the shading film is located in the windshield or on one side surface thereof.

23. The head-up display according to claim 22, characterized in that: The extension directions of the plurality of light-shielding grilles converge at the observation area.

24. The head-up display according to claim 22, characterized in that: The light shielding grid is made of polar material, driving electrodes are arranged at both ends of the light shielding grid, and further comprises: An eyeball positioning device, used to obtain the position information of the user's eyeball; At least one processor is configured to adjust the driving electric field between the driving electrodes at both ends of the light-shielding grille based on the position information of the eyeball, and adjust the angle and position of the light-shielding grille to transmit the first directional light and block the second directional light.

25. The head-up display according to claim 22, characterized in that: The windshield includes an image display area and a non-image display area; the image display area is located on the optical path of the image light; The light shielding film is located in the image display area; or, The shading film includes a first area and a second area, and at least part of the shading grilles in the first area and the shading grilles in the second area extend in different directions; and / or the shading grilles in the first area and the shading grilles in the second area have different arrangement densities; The first area is located in the image display area; and the second area is located in the non-image display area.

Images