Projection device and vehicle

Abstract

The invention relates to a projection device and a vehicle. The projection device comprises a shielding column and a projection assembly, the projection assembly comprises a first holographic projection sheet and a second holographic projection sheet, and the first holographic projection sheet is used for receiving light rays on the side, away from the observation point, of the shielding column and refracting the received light rays to the second holographic projection sheet; and the second holographic projection sheet is used for reflecting the received light to an observation point. According to the projection device, the light of the shielded scene is refracted and reflected to the observation point through the projection assembly for observation, and normal observation of the shielded scene is achieved. When the shielding column is applied to a vehicle, the shielding column can be an A column of the vehicle, so that a driver at a driving position can see the scene outside the A column, and the driving safety is improved.

Description

Technical Field

[0001] The present application relates to the technical field of projection devices, and in particular to a projection device and a vehicle. Background Art

[0002] The A-pillar of a vehicle is the pillar on both sides of the front windshield of the vehicle. It plays an important role in the structural safety of the vehicle, especially in frontal collision and rollover accidents, the A-pillar needs to withstand and disperse a large amount of impact force to protect the safety of the occupants in the vehicle. Therefore, the A-pillar is usually designed to be relatively thick to ensure sufficient strength and rigidity, but this will inevitably lead to blind spots in the driver's field of vision, affecting driving safety.

[0003] Therefore, it is very important to solve the problem of the A-pillar blocking the view. Related technologies usually use image projection, panel projection or modification of the A-pillar to enable the driver to see the scene outside the A-pillar in the driving position, thereby improving driving safety.

[0004] However, the use of image projection in related technologies will result in high power consumption, and the modification of the A-pillar will affect the supporting safety of the vehicle. Summary of the invention

[0005] Based on this, a projection device and a vehicle are provided to enable the driver to see the scene outside the A-pillar in the driving position, thereby improving driving safety and saving electricity. There is no need to modify the A-pillar and the supporting effect of the A-pillar is not affected.

[0006] According to one aspect of the present application, a projection device is provided, the projection device comprising:

[0007] Blocking columns;

[0008] A projection assembly, the projection assembly comprising a first holographic projection film and a second holographic projection film, the first holographic projection film being used to receive light from the side of the shielding column away from the observation point and refract the received light onto the second holographic projection film, the second holographic projection film being used to reflect the received light to the observation point.

[0009] In one embodiment, the angle a between the first holographic projection along a plane perpendicular to the thickness direction of the first holographic projection and the second holographic projection along a plane perpendicular to the thickness direction of the second holographic projection satisfies: 90°≤a≤150°.

[0010] In one embodiment, a first incident angle λ1 of the light incident on the first holographic projection satisfies: 10°≤λ1≤30°, and a first exit angle u1 of the light refracted from the first holographic projection satisfies: 10°≤u1≤89°; and / or

[0011] The second incident angle λ2 of the light incident on the second holographic projection film satisfies: 10°≤λ2≤89°, and the second exit angle u2 of the light reflected from the second holographic projection film satisfies: 0°≤u2≤89°.

[0012] In one embodiment, the first holographic projection film includes a first base layer and a transmission grating layer, wherein the transmission grating layer is stacked on the first base layer, and the transmission grating layer is configured to refract the light from the side of the shielding column away from the observation point onto the second holographic projection film, and the thickness T1 of the first holographic projection film satisfies: 1≤T1≤30um.

[0013] In one embodiment, the second holographic projection film includes a second base layer and a reflection grating layer, wherein the reflection grating layer is stacked on the second base layer, and the reflection grating layer is configured to receive the light refracted by the first holographic projection film and reflect the received light refracted by the first holographic projection film to the observation point. The thickness T2 of the second holographic projection film satisfies: 1≤T2≤30um, and the refractive index difference Δn between the first holographic projection film and the second holographic projection film satisfies: 0.01≤Δn≤0.2.

[0014] In one embodiment, the first holographic projection film includes a first alignment layer and a first liquid crystal layer, and along the thickness direction of the first liquid crystal layer, the liquid crystal molecules in the first liquid crystal layer are arranged in a spiral, and the spiral period length Λ1 of the liquid crystal molecules in the first liquid crystal layer satisfies: 190mm≤Λ1≤500mm, and the thickness c1 of the first liquid crystal layer satisfies: 1um≤c1≤10um; and / or

[0015] The second holographic projection film includes a second alignment layer and a second liquid crystal layer. Along the thickness direction of the second liquid crystal layer, the liquid crystal molecules in the second liquid crystal layer are arranged in a spiral manner, and the spiral period length Λ2 of the liquid crystal molecules in the second liquid crystal layer satisfies: 190mm≤Λ2≤500mm, and the thickness c2 of the second liquid crystal layer satisfies: 1um≤c2≤10um.

[0016] According to one aspect of the present application, a vehicle is provided, comprising the projection device described in any one of the above embodiments.

[0017] In one embodiment, the vehicle includes a windshield, a driving seat is provided in the vehicle, the shielding column is connected to a side of the windshield close to the driving seat, and a portion of the projection assembly is provided on a side of the shielding column facing the driving seat.

[0018] In one embodiment, the first holographic projection is disposed on the windshield of the vehicle.

[0019] In one embodiment, the second holographic projection sheet is disposed on a side of the shielding column facing the driving position.

[0020] The above-mentioned projection device refracts and reflects the light of the obstructed scene to the observation point through the projection component for observation, thereby realizing normal observation of the obstructed scene. When applied in a vehicle, the obstruction column can be the A-pillar of the vehicle, so that the driver in the driving seat can see the scene outside the A-pillar, thereby improving driving safety. And there is no need to modify the A-pillar, which will not affect the support effect of the A-pillar, and is conducive to improving the support safety of the vehicle. At the same time, there is no need to use image projection equipment, which is conducive to saving electricity and energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A simplified schematic diagram of an existing vehicle's A-pillar blocking the driver's sight line at the driving seat.

[0022] Figure 2 This is a front view of a first holographic projection sheet and a second holographic projection sheet disposed in a vehicle in one embodiment of the present application.

[0023] Figure 3 for Figure 2 The illustrated embodiment is a top view of a first holographic projection sheet and a second holographic projection sheet disposed in a vehicle.

[0024] Figure 4 Schematic diagram of the light path of the scene blocked by the A-pillar in one embodiment of the present application after passing through the first holographic projection film and the second holographic projection film in sequence and entering the eyes of the driver in the driving seat.

[0025] Figure 5 for Figure 4 Enlarged view of point B in the middle.

[0026] Figure 6 It is a schematic diagram of the structure of an apparatus for preparing a first holographic projection film or a second holographic projection film in an embodiment.

[0027] Figure 7 This is a schematic diagram of the deflection angle of light passing through the first holographic projection or the second holographic projection to the observation point in an embodiment of the present application.

[0028] Figure 8 This is a schematic structural diagram of a first holographic slide according to an embodiment of the present application.

[0029] Fig. 9 This is a schematic structural diagram of the first holographic projection film of the embodiment of the present application using a liquid crystal structure.

[0030] Description of Figure Numbers:

[0031] 10. Projection device;

[0032] L1, first holographic projection; L2, second holographic projection; 11, first base layer; 12, transmission grating layer; 13, first alignment layer; 14, first liquid crystal layer;

[0033] 21. A-pillar; 22. windshield; 23. side window;

[0034] 31. Laser source; 32. Beam expander; 33. Beam splitter. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0036] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0037] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0038] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0039] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0040] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0041] Generally, there are three pillars on each side of the vehicle body, and the oblique pillars on both sides of the front windshield are called A-pillars. Figure 1 As shown, Figure 1 The following is a simplified schematic diagram of the A-pillar 21 of an existing vehicle blocking the driver's view of the driving seat. The width of the A-pillar 21 is about 100mm-200mm. Whenever the vehicle turns or enters a curve, the driver's field of vision will be partially blocked by the A-pillar 21, resulting in a blind spot in the field of vision. The range of the blind spot or the obstacle angle of the A-pillar 21 is about 5°-15°. In traffic accidents every year, accidents caused by the blind spot of the A-pillar 21 account for about 10%. In order to reduce the proportion of accidents caused by the A-pillar 21 in traffic accidents, it is necessary to solve the problem of the blind spot of the A-pillar 21 blocking the driver's view of the driving seat.

[0042] In the related art, the cross-sectional area of ​​the A-pillar 21 is reduced to reduce the shielding area of ​​the driver by the A-pillar 21, but this will reduce the strength of the A-pillar 21, and even the A-pillar 21 is too small, which will lead to insufficient strength of the vehicle body and affect the support safety of the vehicle. In the related art, panel projection technology is also used, that is, a display panel is set on the A-pillar 21, and the scene blocked by the A-pillar 21 is displayed through the display panel. This method requires the setting of a display panel and a device for obtaining the scene blocked by the A-pillar 21, which has the problem of high cost, and the display panel is set on the A-pillar 21 and needs to be equipped with electrical components, which makes it difficult to repair. In the related art, a projector is also used to project the scene blocked by the A-pillar 21 onto the A-pillar 21 in an attempt to restore the scene behind the A-pillar 21. This method consumes a lot of power and also has the problem of high cost. In addition, the periscope structure is also used in the related art. This structure requires the A-pillar 21 to be modified, which is prone to safety hazards.

[0043] That is, the methods for solving the blind spot of the A-pillar 21 in the related art all have various defects, such as high power consumption, high cost, and affecting the supporting strength of the A-pillar 21.

[0044] Based on this, the present application provides a projection device and a vehicle, so that the driver can see the scene outside the A-pillar 21 or the scene blocked by the A-pillar 21 in the driving position, thereby improving driving safety and saving electricity. There is no need to modify the A-pillar 21, and the supporting effect of the A-pillar 21 will not be affected.

[0045] See also Figure 2 and Figure 3 As shown, Figure 2 This is a front view of the first holographic projection sheet L1 and the second holographic projection sheet L2 disposed in a vehicle in one embodiment of the present application. Figure 3 for Figure 2 The illustrated embodiment is a top view of the first holographic projection sheet L1 and the second holographic projection sheet L2 disposed in a vehicle.

[0046] The projection device 10 of the present application includes a shielding column and a projection assembly, wherein the projection assembly includes a first holographic projection sheet L1 and a second holographic projection sheet L2, wherein the first holographic projection sheet L1 is used to receive light from the shielding column on the side away from the observation point, and refract the received light onto the second holographic projection sheet L2, and the second holographic projection sheet L2 is used to reflect the received light to the observation point. That is, the light is refracted and reflected by the first holographic projection sheet L1 and the second holographic projection sheet L2, so that the light shielded by the shielding column can pass through the first holographic projection sheet L1 and the second holographic projection sheet L2 in sequence and then smoothly enter the observation point position, so as to be observed by the observer at the observation point.

[0047] Correspondingly, the projection assembly is arranged in the vehicle, and the projection assembly can be used to refract and reflect the scene blocked by the A-pillar 21 to the driver's eyes through light, thereby solving the problem of traffic accidents caused by the A-pillar 21 blocking the line of sight. The projection device 10 of the present application can also be applied to other scenes where it is necessary to view the scene blocked behind the blocking object, and no excessive restrictions are made here.

[0048] The projection device 10 of the present application refracts and reflects the light of the obstructed scene to the observation point through the projection component for observation, thereby realizing normal observation of the obstructed scene. At the same time, no power-consuming equipment such as a projector or a display panel is required, which relatively saves energy and reduces the use cost.

[0049] The present application also provides a vehicle, comprising the above-mentioned projection device 10 , so that the driver can smoothly observe the scene blocked by the A-pillar 21 through the projection device 10 .

[0050] In some embodiments, continue to refer to Figure 2 and Figure 3 As shown, the vehicle further includes a windshield 22, the vehicle is provided with the above-mentioned driving position, the shielding column is connected to the side of the windshield 22 close to the driving position, and is located between the windshield 22 and the side window 23 of the vehicle, that is, the shielding column can be the A-pillar 21 of the vehicle. The projection component is arranged on the side of the shielding column facing the driving position, so that the scene light shielded by the A-pillar 21 is refracted and reflected by the projection component and transmitted to the eyes of the driver in the driving position for observation by the driver.

[0051] That is, in the corresponding application in the vehicle, the shielding column can be the A-pillar 21 of the vehicle, so that the driver in the driving position can see the scene outside the A-pillar 21, thereby improving driving safety. The projection component can be partially set on the A-pillar 21, which is easy to install and easy to operate. And there is no need to modify the A-pillar 21, which will not affect the support effect of the A-pillar 21, which is conducive to improving the support safety of the vehicle. At the same time, there is no need to use a display panel, a projector, and a device for obtaining the scene blocked by the A-pillar 21, which is conducive to saving electricity and energy, and is also convenient for maintenance and replacement, with better maintenance convenience.

[0052] In some embodiments, see Figure 2 and Figure 3As shown, the first holographic projection L1 is arranged on the windshield 22 of the vehicle. In this way, the windshield 22 can provide stable support for the first holographic projection L1. At the same time, the first holographic projection L1 is a sheet structure, and the side plane of the first holographic projection L1 perpendicular to its thickness direction can overlap with the plane of the windshield 22 facing the inside of the vehicle, and no other structure is required to install the first holographic projection L1, which can minimize the occupation of the first holographic projection L1 in the vehicle interior space. In addition, the first holographic projection L1 is arranged on the windshield 22 of the vehicle, and the first holographic projection L1 seen by the driver is a transparent projection, which does not affect the driver's observation of the external scene of the windshield 22, which is conducive to the first holographic projection L1 having a better field of view, and is conducive to it receiving the light of the scene outside the vehicle blocked by the A-pillar 21, without the need to set other reflective elements, which is conducive to simplifying the overall structure of the projection device 10 of the present application.

[0053] In some embodiments, continue to refer to Figure 2 and Figure 3 As shown, the second holographic projection L2 is arranged on the side of the shielding column facing the driver's seat. In other words, the second holographic projection L2 is arranged on the side of the A-pillar 21 facing the driver's seat. This is conducive to catering to the driver's operating habits, that is, the scene blocked by the A-pillar 21 or the scene behind the A-pillar 21 is directly projected from the A-pillar 21, which is conducive to more intuitively showing the scene behind the A-pillar 21.

[0054] In some embodiments, see Figure 4 and Figure 5 As shown, Figure 4 Schematic diagram of the light path of the scene blocked by the A-pillar 21 in one embodiment of the present application after passing through the first holographic projection sheet L1 and the second holographic projection sheet L2 in sequence and entering the eyes of the driver in the driving seat. Figure 5 for Figure 4 Enlarged view of point B in the middle.

[0055] Figure 4Schematic diagram of light direction simulated by optical software. In this embodiment, the distance between the human eye of the driver in the driving position and the windshield 22 is 750 mm, that is, the distance between the observation point of the driving position and the windshield 22 is 750 mm, and the distance between the pedestrian blocked by the A-pillar 21 and the intersection of the windshield 22 and the A-pillar 21 is 3 m. The angle between the simulated windshield 22 and the side of the vehicle A-pillar 21 facing the driving position is 40°, and the incident angle of the light incident to the first holographic projection L1 from the direction of the pedestrian blocked by the A-pillar 21 in the distance is 20°. The first holographic projection L1 can refract the incident light with an incident angle of 20° and make it emerge to the second holographic projection L2 at an exit angle of 45°. The light propagated to the second holographic projection L2 is incident on the second holographic projection L2 at an incident angle of 75°, and the second holographic projection L2 reflects the received incident light and makes it emerge to the observation point of the driving position at an exit angle of 20°. That is, in this embodiment, the deflection and diffraction of light is achieved, so that the driver can observe the scene blocked behind the A-pillar 21 through the projection component.

[0056] It can be seen that in this embodiment, the projection component receives the distant scene light blocked by the A-pillar 21 through the first holographic projection film L1. After the first holographic projection film L1 receives the distant scene light blocked by the A-pillar 21, it changes the deflection direction of the received light and refracts the received light to the second holographic projection film L2. After the second holographic projection film L2 receives the light refracted by the first holographic projection film L1, it reflects the light received by the second holographic projection film L2, and its reflection direction is the direction from the second holographic projection film L2 toward the observation point of the driver's seat.

[0057] In some embodiments, the first holographic projection L1 and the second holographic projection L2 of the present application can both use volume holographic optical elements (VHOE), which can completely record the phase and vector waveform of the incident light, refract and reflect the light, and finally propagate the light to the observation point of the driver's seat. Figure 6 As shown, Figure 6 It is a schematic diagram of the structure of an apparatus for preparing a first holographic projection film L1 or a second holographic projection film L2 in an embodiment. Figure 6 The laser light from the laser source 31 passes through the beam expander 32 and then the beam splitter prism 33, and is divided into two incident lights. The interference of the two coherent incident lights is used to generate interference on the corresponding material to form the first holographic projection L1 or the second holographic projection L2. It also involves a reflector to change the propagation direction of the light path, and also involves optical switches, adjustment lenses and holographic dry plates, etc., which will not be repeated here.

[0058] In some embodiments, see Figure 7 As shown in the following Table 1, Figure 7The diagram is a schematic diagram of the deflection angle of light passing through the first holographic projection or the second holographic projection to the observation point in one embodiment of the present application. The angle a between the first holographic projection L1 of the present application along a plane perpendicular to the thickness direction of the first holographic projection L1 and the second holographic projection L2 along a plane perpendicular to the thickness direction of the second holographic projection L2 satisfies: 90°≤a≤150°. When the above range is met, the light incident into the projection device 10 has a better propagation path, which is conducive to the projection device 10 having better imaging quality. And when the above range is met, the projection device 10 of the present application can be applied to most existing vehicles, that is, the first holographic projection L1 is installed on the windshield 22 of the vehicle, and the second holographic projection L2 is installed on the A-pillar 21 next to the driving seat of the vehicle, and the light of the scene blocked by the A-pillar 21 is refracted and reflected to the observation point of the driving seat, so as to achieve normal observation of the blocked scene. The angle between the windshield 22 of an existing vehicle and the side of the vehicle's A-pillar 21 facing the driver's seat is usually around 120°, and the angle a between the first holographic projection film L1 and the second holographic projection film L2 of the present application satisfies the above range, so it can be applied to most existing vehicles.

[0059] Table 1

[0060]

[0061] In some embodiments, continue to refer to Figure 7 As shown in Table 1, the first incident angle λ1 of the light incident on the first holographic projection film L1 satisfies: 10°≤λ1≤30°, and the first exit angle u1 of the light refracted from the first holographic projection film L1 satisfies: 10°≤u1≤89°. It can be understood that the first incident angle λ1 and the first exit angle u1 here refer to that in the process of making the first holographic projection film L1, two coherent incident light beams can be modulated so that the first holographic projection film L1 formed can refract the light from a certain incident direction to another direction and propagate out, that is, refract to a certain exit direction. In other words, the first incident angle λ1 and the first exit angle u1 of the first holographic projection film L1 are selected and set when making the first holographic projection film L1, so that the first holographic projection film L1 can refract the light incident from a specific direction by a specific angle and finally emit from a specific direction.

[0062] In some embodiments, Figure 7As shown in Table 1, the second incident angle λ2 of the light incident on the second holographic projection film L2 satisfies: 10°≤λ2≤89°, and the second exit angle u2 of the light reflected from the second holographic projection film L2 satisfies: 0°≤u2≤89°. It can be understood that the second incident angle λ2 and the second exit angle u2 mean that in the process of making the second holographic projection film L2, two coherent incident light beams can be modulated so that the second holographic projection film L2 formed can reflect the light from a certain incident direction to another direction and propagate out, that is, reflect to a certain exit direction and exit. In other words, the second incident angle λ2 and the second exit angle u2 of the second holographic projection film L2 are selected and set when making the second holographic projection film L2, so that the second holographic projection film L2 can reflect the light incident from a specific direction at a specific angle and finally exit from a specific direction.

[0063] In some embodiments, see Figure 8 As shown, Figure 8 The schematic diagram of the structure of the first holographic projection film L1 of an embodiment of the present application. The first holographic projection film L1 includes a first base layer 11 and a transmission grating layer 12. The transmission grating layer 12 is stacked on the first base layer 11. The transmission grating layer 12 is configured to refract the light on the side of the shielding column away from the observation point to the second holographic projection film L2. The thickness T1 of the first holographic projection film satisfies: 1≤T1≤30um. According to the angle between the windshield 22 of different vehicles and the side of the A-pillar 21 of the vehicle facing the driver's seat, as well as the specific size of the A-pillar 21 and the obstacle angle of the A-pillar 21, the grating structure of the transmission grating layer 12 can be designed, and the corresponding grating structure of the transmission grating layer 12 can be prepared by adjusting the incident angles and incident light parameters of the two coherent incident light beams. The first holographic projection film L1 has a suitable first incident angle λ1 and a first exit angle u1. In this embodiment, the structural arrangement of the first base layer 11 and the transmission grating layer 12 enables the first holographic projection film L1 to have the advantages of high diffraction efficiency, a wider spectral range (helpful in coping with various natural environments during vehicle driving), higher resolution, low stray light and no ghost lines.

[0064] In some embodiments, similar to the first holographic projection film L1, the second holographic projection film L2 includes a second base layer and a reflective grating layer, the reflective grating layer is stacked on the second base layer, the reflective grating layer is configured to receive the light refracted by the first holographic projection film L1, and reflect the received light refracted by the first holographic projection film L1 to the observation point, the thickness T2 of the second holographic projection film satisfies: 1≤T2≤30um, and the refractive index difference Δn between the first holographic projection film and the second holographic projection film satisfies: 0.01≤Δn≤0.2. The grating structure of the corresponding reflective grating layer is prepared by the incident angle and incident light parameters of the two coherent incident light beams to form a reflective grating. According to the actual application conditions (such as the angle between the vehicle windshield 22 and the side of the vehicle's A-pillar 21 facing the driver's seat, the specific size of the A-pillar 21 and the obstacle angle of the A-pillar 21, etc.), and the design of the first holographic projection film L1, the incident angles and incident light parameters of the two coherent incident light beams can be adjusted to prepare the corresponding grating structure of the reflective grating layer. The second holographic projection film L2 is provided with a suitable second incident angle λ2 and a second exit angle u2. The structural arrangement of the second base layer and the reflective grating layer enables the second holographic projection film L2 to have the advantages of high diffraction efficiency, a wider spectral range (conducive to coping with various natural environments during vehicle driving), higher resolution, low stray light and no ghost lines.

[0065] In some embodiments, see Fig. 9 As shown, Fig. 9 The schematic diagram of the structure of the first holographic projection film L1 of the embodiment of the present application adopting the liquid crystal structure. The first holographic projection film L1 includes a first alignment layer 13 and a first liquid crystal layer 14. Along the thickness direction of the first liquid crystal layer 14, the liquid crystal molecules in the first liquid crystal layer 14 are arranged in a spiral, and the spiral period length Λ1 satisfies: 190mm≤Λ1≤500mm, and the thickness c1 of the first liquid crystal layer 14 satisfies: 1um≤c1≤10um. That is, the present application can adopt the first holographic projection film L1 with a liquid crystal structure to realize the refraction of light by the first holographic projection film L1. Among them, the first alignment layer 13 is used to guide the arrangement direction of the liquid crystal molecules in the first liquid crystal layer 14. And the spiral period of the liquid crystal molecules in the first liquid crystal layer 14 and the thickness of the first liquid crystal layer 14 meet the above range, which is conducive to improving the spectral range of the light received by the first holographic projection film L1 and improving the imaging quality of the projection device 10. In this embodiment, the first holographic projection film L1 with a liquid crystal structure is beneficial to improving the response speed of the first holographic projection film L1, and improving the polarization stability of the first holographic projection film L1. At the same time, the first holographic projection film L1 has the advantages of low stray light, no high-order extension, better adjustability and low cost.

[0066] In some embodiments, similar to the first holographic projection film L1, the second holographic projection film L2 includes a second alignment layer and a second liquid crystal layer. Along the thickness direction of the second liquid crystal layer, the liquid crystal molecules in the second liquid crystal layer are arranged in a spiral, and the spiral period length Λ2 satisfies: 190mm≤Λ2≤500mm, and the thickness c2 of the second liquid crystal layer satisfies: 1um≤c2≤10um. That is, the second holographic projection film L2 with a liquid crystal structure can be used in the present application. Among them, the second alignment layer is used to guide the arrangement direction of the liquid crystal molecules in the second liquid crystal layer. And the spiral period of the liquid crystal molecules in the second liquid crystal layer and the thickness of the second liquid crystal layer meet the above ranges, which is conducive to improving the spectral range of the light received by the second holographic projection film L2 and improving the imaging quality of the projection device 10. And the second holographic projection film L2 with a liquid crystal structure in this embodiment is conducive to improving the response speed of the second holographic projection film L2, and is conducive to improving the polarization stability of the second holographic projection film L2, and at the same time, the second holographic projection film L2 has the advantages of low stray light, no high-order extension, better adjustability and low cost.

[0067] The vehicle provided in the present application includes the projection device 10 in any of the above embodiments, and the configuration of the first holographic projection sheet L1 and the second holographic projection sheet L2 of any of the above structural types can be selected according to the requirements.

[0068] The projection device 10 provided in the present application refracts and reflects the light of the obstructed scene to the observation point through the projection component for observation, thereby realizing normal observation of the obstructed scene. When applied in a vehicle, the obstruction column can be the A-pillar 21 of the vehicle, so that the driver in the driving seat can see the scene outside the A-pillar 21, thereby improving driving safety. And there is no need to modify the A-pillar 21, which will not affect the support effect of the A-pillar 21, and is conducive to improving the support safety of the vehicle. At the same time, there is no need to use image projection equipment, which is conducive to saving electricity and energy.

[0069] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A holographic projection device, characterized in that: The projection device comprises: A shielding column; and a projection assembly, the projection assembly comprising a first holographic projection film and a second holographic projection film, the first holographic projection film being used to receive light from the side of the shielding column away from the observation point and refract the received light onto the second holographic projection film, and the second holographic projection film being used to reflect the received light to the observation point.

2. The projection device according to claim 1, characterized in that: The angle a between the first holographic projection film along a plane perpendicular to the thickness direction of the first holographic projection film and the second holographic projection film along a plane perpendicular to the thickness direction of the second holographic projection film satisfies: 90°≤a≤150°.

3. The projection device according to claim 1, characterized in that: A first incident angle λ1 of the light incident on the first holographic projection satisfies: 10°≤λ1≤30°, and a first exit angle u1 of the light refracted from the first holographic projection satisfies: 10°≤u1≤89°; and / or The second incident angle λ2 of the light incident on the second holographic projection film satisfies: 10°≤λ2≤89°, and the second exit angle u2 of the light reflected from the second holographic projection film satisfies: 0°≤u2≤89°.

4. The projection device according to claim 1, characterized in that: The first holographic projection film includes a first base layer and a transmission grating layer, wherein the transmission grating layer is stacked on the first base layer, and the transmission grating layer is configured to refract the light from the side of the shielding column away from the observation point onto the second holographic projection film, and the thickness T1 of the first holographic projection film satisfies: 1≤T1≤30um.

5. The projection device according to claim 4, characterized in that: The second holographic projection film includes a second base layer and a reflection grating layer, and the reflection grating layer is stacked on the second base layer. The reflection grating layer is configured to receive the light refracted by the first holographic projection film and reflect the received light refracted by the first holographic projection film to the observation point. The thickness T2 of the second holographic projection film satisfies: 1≤T2≤30um, and the refractive index difference Δn between the first holographic projection film and the second holographic projection film satisfies: 0.01≤Δn≤0.

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6. The projection device according to claim 1, characterized in that: The first holographic projection film comprises a first alignment layer and a first liquid crystal layer, and along the thickness direction of the first liquid crystal layer, the liquid crystal molecules in the first liquid crystal layer are arranged in a spiral, and the spiral period length Λ1 of the liquid crystal molecules in the first liquid crystal layer satisfies: 190mm≤Λ1≤500mm, and the thickness c1 of the first liquid crystal layer satisfies: 1um≤c1≤10um; and / or The second holographic projection film includes a second alignment layer and a second liquid crystal layer. Along the thickness direction of the second liquid crystal layer, the liquid crystal molecules in the second liquid crystal layer are arranged in a spiral manner, and the spiral period length Λ2 of the liquid crystal molecules in the second liquid crystal layer satisfies: 190mm≤Λ2≤500mm, and the thickness c2 of the second liquid crystal layer satisfies: 1um≤c2≤10um.

7. A vehicle, characterized in that: The invention comprises a projection device as claimed in any one of claims 1 to 6.

8. The vehicle according to claim 7, characterized in that The vehicle comprises a windshield, a driving seat is arranged in the vehicle, the shielding column is connected to a side of the windshield close to the driving seat, and a part of the projection assembly is arranged on a side of the shielding column facing the driving seat.

9. The vehicle according to claim 8, characterized in that The first holographic projection sheet is disposed on the windshield of the vehicle.

10. The vehicle according to claim 8, characterized in that The second holographic projection sheet is arranged on a side of the shielding column facing the driving position.

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