Projection module with large projection picture and vehicle provided with projection module

Abstract

The invention discloses a projection module with a large projection picture and a vehicle provided with the projection module. The projection module comprises an illumination system, an image generation unit, a projection system and a dimming element, light emitted by the illumination system lightens the image generation unit to generate an image to be projected, and light of the image is projected to the dimming element through the projection system. Wherein one part of the light is transmitted by the dimming element to one side of a target surface to form a projection pattern, the other part of the light is reflected by the dimming element to the other side of the target surface to form a projection pattern, and the projection patterns on the two sides form a projection picture on the target surface. According to the projection module, two symmetrical patterns can be projected at the same time through one projection module, the projection range is expanded, the difficulty of installation and debugging is low, the definition of a projection picture can be improved, and the cost of the projection module is reduced.

Description

Technical Field

[0001] Embodiments of the present application relate to the technical field of automobiles, and in particular to a projection module with a large projection screen and a vehicle equipped with the projection module. Background Art

[0002] With the development of projection technology, the application of projection technology in the automotive field has become increasingly widespread, such as reverse contour indication and warning. Usually when reversing, two symmetrical and eye-catching warning patterns need to be projected on the ground about 1 meter behind the left and right brake lights of the vehicle respectively. The brightness requirement for the patterns is very high, and the left-right distance between the two patterns needs to be at least the same as the vehicle width. Therefore, the size of the overall picture composed of the two patterns is very large.

[0003] Currently, there are two main implementation solutions: one is to install an independent projection lamp module at each of the left rear end and the right rear end of the vehicle, and the two projection lamp modules are respectively used to project the warning patterns on the left rear and the right rear of the vehicle; the other is to install a projection lamp module near the reverse camera module in the middle of the rear end of the vehicle, and a projection lamp module projects an overall picture, which simultaneously includes the warning patterns on the left rear and the right rear of the vehicle.

[0004] However, the above two implementation solutions have problems such as difficult installation, high cost, and low clarity of the projected patterns in actual use. Summary of the Invention

[0005] A projection module with a large projection screen and a vehicle equipped with the projection module provided by the embodiments of the present application can solve or partially solve the above-mentioned deficiencies in the prior art or other deficiencies in the prior art.

[0006] According to a first aspect of the present application, a projection module with a large projection screen is provided, including: an illumination system, an image generation unit, a projection system, and a dimming element. Among them, the light emitted by the illumination system lights up the image generation unit to generate an image to be projected. The light of the image is projected onto the dimming element through the projection system. A part of the light is transmitted by the dimming element to one side of the target surface to form a projection pattern, and another part of the light is reflected by the dimming element to the other side of the target surface to form a projection pattern. The projection patterns on both sides form a projection screen on the target surface.

[0007] In an embodiment of the present application, the proportion P of the projection pattern within the projection range of the projection system on the target surface is P≥70%.

[0008] In an embodiment of the present application, the two projection patterns are symmetrical about the dimming element.

[0009] In an embodiment of the present application, the included angle θ between the dimming element and the optical axis of the projection system satisfies: 25° ≤ θ ≤ 65°.

[0010] In an embodiment of the present application, the length L of the projection screen satisfies L ≥ 1600 mm, and the field of view angle FOV of the projection system satisfies FOV ≤ 60°.

[0011] In an embodiment of the present application, the dimming element includes a beam splitter. The light projected onto the beam splitter is divided into two beams of light in the full wavelength band. One beam of light is transmitted by the beam splitter to form the projection pattern, and the other beam of light is reflected by the beam splitter to form the projection pattern.

[0012] In an embodiment of the present application, the dimming element includes a filter. The light projected onto the filter is divided into two beams of light in different wavelength bands. One beam of light is transmitted by the filter to form the projection pattern, and the other beam of light is reflected by the filter to form the projection pattern.

[0013] In an embodiment of the present application, the field of view angle α of the light reflected by the dimming element, the field of view angle β of the light transmitted by the dimming element, the field of view angle γ of the projection screen, and the included angle θ between the dimming element and the optical axis of the projection system satisfy: γ ≥ α + β + 15°, γ ≤ 2 * θ + 1 / 2(α + β) + 20°.

[0014] In an embodiment of the present application, the field of view angle α of the light reflected by the dimming element and the included angle θ between the dimming element and the optical axis of the projection system satisfy: 0.5 * α + θ ≤ 80°.

[0015] In an embodiment of the present application, the distance D between the center of the light incident surface of the dimming element and the center of the light exit surface of the projection system, the field of view angle α of the light reflected by the dimming element, and the included angle θ between the dimming element and the optical axis of the projection system satisfy: D ≥ tan(0.5α + 2θ - 90°) * 7.

[0016] In an embodiment of the present application, the distance D between the center of the light incident surface of the dimming element and the center of the light exit surface of the projection system is 10 mm to 20 mm.

[0017] In an embodiment of the present application, the dimming element includes one of a flat lens, a meniscus lens, a biconcave lens, a biconvex lens, a wedge lens, and a prism.

[0018] In an embodiment of the present application, the dimming element is a flat lens with an incident surface and an exit surface being parallel planes; wherein, the transmittance Tabs of the incident surface in the working wavelength band λ of 420 nm to 680 nm is 30% to 70%, and the reflectance Rabs is 30% to 70%; the transmittance Tabs of the exit surface in the working wavelength band λ of 420 nm to 680 nm is ≥ 92%.

[0019] In an embodiment of the present application, the dimming element is a flat lens with an incident surface and an exit surface being parallel planes; wherein, the reflectance Rabs of the incident surface in the working wavelength band λ of 420 nm to 530 nm is ≥ 90%, and the transmittance Tabs in the working wavelength band λ of 535 nm to 680 nm is ≥ 92%; the transmittance Tabs of the exit surface in the working wavelength band λ of 420 nm to 680 nm is ≥ 92%.

[0020] In an embodiment of the present application, the dimming element is a meniscus lens with a curved incident surface and a curved exit surface; wherein, the transmittance Tabs of the incident surface in the working wavelength band λ of 420 nm to 680 nm is 30% to 70%, and the reflectance Rabs is 30% to 70%; the transmittance Tabs of the exit surface in the working wavelength band λ of 420 nm to 680 nm is ≥ 92%.

[0021] In an embodiment of the present application, the dimming element is a meniscus lens with a curved incident surface and a curved exit surface; wherein, the reflectance Rabs of the incident surface in the working wavelength band λ of 420 nm to 530 nm is ≥ 90%, and the transmittance Tabs in the working wavelength band λ of 535 nm to 680 nm is ≥ 92%; the transmittance Tabs of the exit surface in the working wavelength band λ of 420 nm to 680 nm is ≥ 92%.

[0022] In an embodiment of the present application, the dimming element is a wedge lens with an incident surface and an exit surface being planes at a certain angle; wherein, the transmittance Tabs of the incident surface in the working wavelength band λ of 420 nm to 680 nm is 30% to 70%, and the reflectance Rabs is 30% to 70%; the transmittance Tabs of the exit surface in the working wavelength band λ of 420 nm to 680 nm is ≥ 92%.

[0023] According to a second aspect of the present application, a vehicle is provided, including the projection module for a large projection screen described in the first aspect.

[0024] In an embodiment of the present application, the projection module for the large projection screen is installed near the reverse camera module in the exact middle at the rear end of the vehicle, and is used for projecting reverse contour or warning patterns.

[0025] The projection module for a large projection screen and the vehicle equipped with the projection module provided by the embodiments of the present application can project two symmetric patterns simultaneously through one projection module by adding a dimming element at the front end of the projection system, expanding the projection range, ensuring the left - right symmetry and consistency of the two patterns, reducing the difficulty of debugging the symmetry position of the projection screen, lowering the installation difficulty, saving the cost of one projection module, not requiring the projection system to have a large field of view, thereby enhancing the light control ability of the projection system, improving the clarity of the projection screen, reducing the number of optical lenses in the projection system, thus reducing the cost of the projection module, ensuring a large proportion of the projection pattern in the projection screen, high light utilization rate, and enabling the selection of a medium - low power lighting system, reducing the requirements for the heat dissipation system and the cost of the projection module.

[0026] The content described in this part is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it used to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Other features, objects, and advantages of the present application will become more apparent by reading the detailed description of the non - restrictive embodiments with reference to the following drawings. The drawings are used to better understand the solution and do not limit the present application. Among them:

[0028] Figure 1 is a block diagram of a projection module for a large projection screen according to an embodiment of the present application;

[0029] Figure 2 is an optical system diagram of a projection module for a large projection screen according to an embodiment of the present application;

[0030] Figure 3 is a schematic diagram of a dimming element according to an embodiment of the present application;

[0031] Figure 4 is a schematic diagram of the projection screen formed on the ground by a projection module for a large projection screen according to an embodiment of the present application;

[0032] Figure 5 is an optical system diagram of a projection module for a large projection screen according to another embodiment of the present application;

[0033] Figure 6 is a schematic diagram of a dimming element according to another embodiment of the present application;

[0034] Figure 7 is a schematic diagram of the projection screen formed on the ground by a projection module for a large projection screen according to another embodiment of the present application;

[0035] Figure 8 It is an optical system diagram of a projection module for a large projection screen according to another embodiment of the present application;

[0036] Figure 9 It is a schematic diagram of a dimming element according to another embodiment of the present application;

[0037] Figure 10 It is a schematic diagram of a projection screen formed on the ground by a projection module for a large projection screen according to another embodiment of the present application;

[0038] Figure 11 It is an optical system diagram of a projection module for a large projection screen according to still another embodiment of the present application;

[0039] Figure 12 It is a schematic diagram of a dimming element according to still another embodiment of the present application;

[0040] Figure 13 It is a schematic diagram of a projection screen formed on the ground by a projection module for a large projection screen according to still another embodiment of the present application;

[0041] Figure 14 It is an optical system diagram of a projection module for a large projection screen according to yet another embodiment of the present application;

[0042] Figure 15 It is a schematic diagram of a dimming element according to yet another embodiment of the present application. Detailed implementation manners

[0043] The following makes an explanation of the exemplary embodiments of the present application in conjunction with the accompanying drawings. Various details of the embodiments of the present application are included to assist in understanding, and they should be considered merely exemplary. Therefore, those of ordinary skill in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted below.

[0044] In the accompanying drawings, for the convenience of explanation, the thickness, dimensions, and shapes of the components have been slightly adjusted. The accompanying drawings are only examples and are not drawn strictly to scale. As used herein, terms such as "substantially", "approximately", and similar terms are used as approximate terms and not as terms of degree, and are intended to illustrate the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art.

[0045] It should also be understood that expressions such as "including", "comprising", "having", "containing" and / or "comprising of" are open-ended rather than closed-ended expressions in this specification, which means that the stated features, elements and / or components exist, but do not exclude the existence of one or more other features, elements, components and / or their combinations. In addition, when an expression such as "at least one of..." appears after a list of listed features, it modifies the entire list of features rather than just individual elements in the list. In addition, when describing the embodiments of the present application, the use of "may" means "one or more embodiments of the present application". And the term "exemplary" is intended to refer to an example or illustration.

[0046] Unless otherwise defined, all terms used herein (including engineering terms and technical terms) shall have the same meaning as the ordinary understanding of those of ordinary skill in the art to which this application pertains. It should also be understood that unless there is a clear description in this application, words defined in common dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense.

[0047] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. In addition, unless clearly defined or in contradiction with the context, the specific steps included in the methods described in this application do not have to be limited to the recorded order, but can be executed in any order or executed in parallel.

[0048] In addition, those skilled in the art can understand that the quantities shown in the drawings and the following text of this application, such as the quantity of the light film, etc., are only shown for the convenience of illustration, and without departing from the teachings of the disclosure of this application, the specific quantity can be set according to actual needs.

[0049] With the development of projection technology, the application of projection technology in the automotive field is becoming more and more extensive, such as reverse contour indication and warning, etc. Usually when reversing, it is necessary to project two symmetrical and eye-catching warning patterns on the ground about 1 meter behind the left brake light of the vehicle (hereinafter referred to as the left rear of the vehicle) and about 1 meter behind the right brake light of the vehicle (hereinafter referred to as the right rear of the vehicle). In order to achieve the purpose of warning, the brightness requirement of the patterns is very high, and the left-right distance between the two patterns, that is, the distance outside the two patterns needs to be at least the same as the vehicle width. For example, for a sedan, the left-right distance between the two patterns is between 1.6 and 1.8 meters, and the size of the overall picture composed of the two patterns is very large.

[0050] There are currently two mainstream implementation solutions: one is to install an independent projection lamp module at each of the left rear end and the right rear end of the vehicle, and the two projection lamp modules are respectively used to project warning patterns on the left rear and the right rear of the vehicle alone; the other is to install a projection lamp module near the reverse camera module in the exact middle of the rear end of the vehicle, and a single projection lamp module projects an overall picture that simultaneously includes warning patterns on the left rear and the right rear of the vehicle.

[0051] However, the above two implementation solutions have the following problems in the actual use process:

[0052] 1. For the implementation solution with two independent projection lamp modules, in order to ensure the symmetry and consistency of the left and right patterns, it is necessary to adjust the position of the projection screen of the projection lamp module during the installation process, and the installation difficulty is relatively high.

[0053] 2. For the implementation solution with two independent projection lamp modules, the overall cost of using two projection lamp modules is relatively high.

[0054] 3. For the implementation solution with a single projection lamp module, a single projection lamp module directly projects a picture containing two patterns. The length of the picture needs to reach at least 1.6m, the projection system needs a field of view angle of at least more than 100°, and the number of optical lenses of the projection system needs to be 2 pcs more than that of a conventional projection system, and it needs to be guaranteed to be 5 pcs or more. The overall cost of the projection lamp module is relatively high.

[0055] 4. For the implementation solution with a single projection lamp module, a single projection lamp module directly projects a picture containing two patterns. The length of the picture needs to reach at least 1.6m, the projection system needs a field of view angle of at least more than 100°, the light control ability of the projection system will decrease, resulting in a decrease in the resolution of the projection screen, and the warning pattern projected onto the ground is not clear enough.

[0056] 5. For the implementation solution with a single projection lamp module, a single projection lamp module directly projects a picture containing two patterns. The length of the picture needs to reach at least 1.6m, the projection system needs a field of view angle of at least more than 100°, the proportion P of the warning pattern in the projection screen ≤ 10%, and the light utilization rate is very low. Since the brightness requirement for the warning pattern projected onto the ground is very high, high-power lamp beads need to be selected for lighting, resulting in an increase in the cost of the projection lamp module. The high-power lamp beads also have higher requirements for the heat dissipation system, resulting in an increase in the cost of the heat dissipation system.

[0057] To solve the above problems, an embodiment of the present application provides a projection module 1000 with a large projection screen.

[0058] Figure 1The block diagram of the projection module 1000 for a large projection screen according to an embodiment of the present application is shown. As Figure 1 shown, the projection module 1000 for a large projection screen may include: an illumination system 100, an image generation unit 200, a projection system 300, and a dimming element 400. Among them, the light emitted by the illumination system 100 lights up the image generation unit 200 to generate an image to be projected. The light of the image to be projected passes through the projection system 300 and is projected onto the dimming element 400. A part of the light is transmitted by the dimming element 400 to form a projection pattern on one side of the target surface, and another part of the light is reflected by the dimming element 400 to form a projection pattern on the other side of the target surface. The projection patterns on both sides form a projection screen on the target surface.

[0059] In the projection module 1000 for a large projection screen according to the embodiment of the present application, by adding a dimming element 400 at the front end of the projection system 300, after the light emitted by the illumination system 100 lights up the image generation unit 200 to generate an image to be projected, the light of the image passes through the projection system 300 and is projected onto the dimming element 400. The dimming element 400 adjusts the image light projected by the projection system 300, divides the image light into two parts. One part of the image light passes through the dimming element 400 to form a transmission optical path and is projected onto one side of the target surface to form a projection pattern of the transmission optical path. Another part of the image light is reflected by the dimming element 400 to form a reflection optical path and is projected onto the other side of the target surface to form a projection pattern of the reflection optical path. The projection pattern of the transmission optical path and the projection pattern of the reflection optical path are spliced into a projection screen on the target surface.

[0060] In the projection module 1000 for a large projection screen according to the embodiment of the present application, by adding a dimming element 400 at the front end of the projection system 300, it is possible to project two symmetric patterns simultaneously through one projection module, expanding the projection range, and being able to ensure that the two patterns are symmetric and consistent left and right, reducing the difficulty of debugging the symmetry position of the projection screen, reducing the installation difficulty, and saving the cost of one projection module. It does not require the projection system to have a large field of view angle, thereby enhancing the light control ability of the projection system, improving the clarity of the projection screen, and at the same time reducing the number of optical lenses of the projection system, thereby reducing the cost of the projection module, ensuring that the projection pattern occupies a relatively large proportion in the projection screen, and having a high light utilization rate. Thus, a medium or low power illumination system can be selected, reducing the requirements for the heat dissipation system and reducing the cost of the projection module.

[0061] It should be noted that the present application does not limit the composition and implementation manner of the illumination system 100. For example, the illumination system 100 can use an LED light source or a laser light source.

[0062] It should be noted that the embodiments of the present application do not limit the type of the image generation unit 200 and the type of the image generated by the image generation unit 200, etc. For example, the image generation unit 200 may use a film, or may use a Digital Micromirror Device (DMD) chip. When the image generation unit 200 uses a film, the generated image is static. When the image generation unit 200 uses a DMD chip, the generated image may be dynamic. In addition, the image generation unit 200 may also include, but is not limited to, an LCOS chip or a MEMS chip, etc.

[0063] It should be noted that the embodiments of the present application do not limit the type and quantity of the optical lenses constituting the projection system 300, etc. For example, the projection system 300 may be composed of 3 lenses, and the 3 lenses may be a biconvex lens, a concave-convex lens, and a convex-concave lens respectively.

[0064] It should be noted that the embodiments of the present application do not limit the material, shape, and composition structure of the dimming element 400, etc. For example, the dimming element 400 may include one of a flat lens, a meniscus lens, a biconcave lens, a biconvex lens, a wedge lens, and a prism. The dimming element 400 may be made of a transparent material of the above shapes, such as glass or plastic, etc. The dimming element 400 may realize the functions of light splitting, transmission, and reflection by performing optical coating on the lenses of the transparent material of the above shapes.

[0065] In some alternative embodiments of the present application, the length L of the symmetric projection screen formed on the target surface and including two projection patterns satisfies L≥1600mm, and the field of view angle FOV of the projection system 300 satisfies FOV≤60°. Optionally, the field of view angle FOV of the projection system 300 satisfies FOV≤40°. In an alternative example, the field of view angle FOV of the projection system 300 is FOV = 30°. Since the symmetric projection screen is formed by projecting and reflecting image light to splice the projection patterns, the field of view angle of the entire projection screen can be increased or decreased by adjusting the angle between the dimming element 400 and the projection system 300. Compared with the existing implementation scheme of projecting a screen containing two patterns by one projection lamp module, the field of view angle of the projection system 300 can be reduced, making the projection screen clearer, and the number of optical lenses of the projection system 300 can be reduced by at least 2 pcs, thereby effectively reducing the cost of the projection module 1000.

[0066] In some alternative embodiments of the present application, the proportion P of the projection pattern on the target surface within the projection range of the projection system 300 on the target surface is P≥70%, that is, the effective utilization rate of the projection range is greater than or equal to 70%. In an alternative example, the proportion P of the projection pattern on the target surface within the projection range of the projection system 300 on the target surface is 90%. Since the matching degree between the projection pattern and the field of view angle of the projection system 300 is relatively high, the light efficiency utilization rate is high, the brightness of the projection pattern is high, and the requirement for the luminous flux output by the lamp beads of the lighting system 100 is relatively low, which can effectively reduce the costs of the lamp beads and the heat dissipation system.

[0067] In some alternative embodiments of the present application, the two projection patterns are symmetric about the dimming element 400, that is, the left-right consistency of the two projection patterns is good. The two projection patterns obtained by the dimming element 400 through transmission and reflection projection originate from the same projection system 300, and the left-right consistency of the two projection patterns is good. Especially when using a flat dimming element 400, the sizes and shapes of the two projection patterns obtained by projection are exactly the same. Compared with the existing implementation scheme using two independent projection lamp modules, the assembly tolerance will cause differences in the projection patterns. The projection module 1000 provided by the embodiments of the present application can easily realize the projection of symmetric patterns with good left-right consistency.

[0068] In some alternative embodiments of the present application, the angle θ between the dimming element 400 and the optical axis of the projection system 300 can satisfy: 25°≤θ≤65°. Optionally, 35°≤θ≤55°. By making the angle θ between the dimming element 400 and the optical axis of the projection system 300 within the above range, various application scenarios can be adapted, the applicable range of the projection module 1000 can be expanded, and by adjusting the angle between the dimming element 400 and the projection system 300, the projection position of the projection pattern can be changed. Compared with the existing implementation scheme of projecting a picture containing two patterns by a single projection lamp module, the projection module 1000 provided by the embodiments of the present application can quickly adapt to various application scenarios without the need to re-design and process the lens module.

[0069] In some alternative embodiments of the present application, the dimming element 400 may include a beam splitter. The image light projected by the projection system 300 onto the beam splitter is divided into two beams of light in the full wavelength band. One beam of light is transmitted through the beam splitter to form a projection pattern, and the other beam of light is reflected by the beam splitter to form a projection pattern. By using a beam splitter as the dimming element 400, the image light projected onto the dimming element 400 can be partially transmitted and partially reflected in the full wavelength band to form two projection patterns with exactly the same color. For example, when the image light projected by the projection system 300 onto the beam splitter is white light or monochromatic light, the two projection patterns formed after transmission and reflection by the beam splitter are both white light or monochromatic light.

[0070] In some alternative embodiments of the present application, the dimming element 400 may include a filter. The image light projected by the projection system 300 onto the filter is divided into two paths of light of different wavelength bands. One path of light is transmitted by the filter to form a projection pattern, and the other path of light is reflected by the filter to form a projection pattern. By using a filter as the dimming element 400, the light of different wavelength bands in the image light projected onto the dimming element 400 can be screened, so that the light of some wavelength bands is transmitted and the light of some other wavelength bands is reflected, which can achieve the projection effect of different colors for the left and right projection patterns. By making the left and right projection patterns have different colors, it can be applied to welcome lights, etc. to achieve personalized projection, can adapt to a variety of application scenarios, and expand the applicable range of the projection module 1000. For example, when the dimming element 400 is a blue-yellow filter and the image light projected by the projection system 300 onto the filter is white light, the blue-yellow light passing through the filter is reflected to form a green projection pattern, and the light of the remaining colors is transmitted to form a red projection pattern.

[0071] In some alternative embodiments of the present application, the field of view angle α of the light reflected by the dimming element 400, the field of view angle β of the light transmitted by the dimming element 400, the field of view angle γ of the symmetric projection screen, and the angle θ between the dimming element 400 and the optical axis of the projection system 300 may satisfy: γ≥α + β + 15°, γ≤2*θ + 1 / 2(α + β) + 20°. By making the field of view angle α of the reflected light, the field of view angle β of the transmitted light, the field of view angle γ of the symmetric projection screen, and the angle θ between the dimming element 400 and the optical axis of the projection system 300 satisfy the above conditional formula, by adjusting the field of view angle of the projection system 300, the field of view angle α of the reflected light and the field of view angle β of the transmitted light can be adjusted, and in cooperation with the angle between the dimming element 400 and the projection module 1000, the inclination of the optical path can be achieved, so that the distance of the optical path to the target surface can be adjusted, and the size of the field of view angle of the entire projection screen can be adjusted.

[0072] In some alternative embodiments of the present application, the field of view angle α of the light reflected by the dimming element 400 and the angle θ between the dimming element 400 and the optical axis of the projection system 300 may satisfy: 0.5*α + θ≤80°. By making the field of view angle α of the reflected light generated by the dimming element 400 and the angle θ between the dimming element 400 and the optical axis of the projection system 300 satisfy the above conditional formula, by adapting the angle θ between the dimming element 400 and the optical axis of the projection system 300, the expansion of the field of view angle of the entire projection screen can be achieved. In addition, by making α and θ satisfy the above conditional formula, when α and θ are matched, the ranges of α and θ can also be restricted to prevent the interference between the transmission optical path and the reflection optical path, resulting in the missing of the projection screen.

[0073] In some alternative embodiments of the present application, the distance D between the center of the light incident surface of the dimming element 400 and the center of the light exit surface of the projection system 300, the field angle α of the light reflected by the dimming element 400, and the angle θ between the dimming element 400 and the optical axis of the projection system 300 may satisfy: D ≥ tan(0.5α + 2θ - 90°) * 7. By making the distance D along the optical axis direction between the dimming element 400 and the center of the light exit surface of the projection system 300, the field angle α of the reflected light generated by the dimming element 400, and the angle θ between the dimming element 400 and the optical axis of the projection system 300 satisfy the above conditional formula, the expansion of the field angle of the entire projection screen can be achieved by adapting the distance D between the dimming element 400 and the light exit surface of the projection system 300. In addition, since an overly large D size will cause an increase in the size of the dimming element 400, thereby increasing the volume of the module 1000, and an overly small D size will cause interference between the dimming element 400 and the projection system 300, by making D, α, and θ satisfy the above conditional formula, the size range of D can be limited within the range of this conditional formula to achieve an optimal effect.

[0074] The projection module 1000 for a large projection screen provided by the embodiments of the present application will be described below with reference to the accompanying drawings and specific embodiments.

[0075] In some alternative embodiments of the present application, as Figure 2 shown, the projection module 1000 for a large projection screen includes: an illumination system 100, an image generation unit 200, a projection system 300, and a dimming element 400. Among them, the illumination system 100, the image generation unit 200, and the projection system 300 form the optical system 600 of the projection module. The parallel light emitted by the illumination system 100 lights up the image generation unit 200 to generate an image to be projected. The light of the image to be projected passes through the projection system 300 and is projected onto the dimming element 400. The dimming element 400 divides it into two parts. One part of the light is transmitted by the dimming element 400 to form a transmission optical path 510, and finally a projection pattern 511 of the transmission optical path is formed on one side of the target surface. The other part of the light is reflected by the dimming element 400 to form a reflection optical path 520, and finally a projection pattern 521 of the reflection optical path is formed on the other side of the target surface. The projection pattern 511 of the transmission optical path and the projection pattern 521 of the reflection optical path form a projection screen 500 that is radially symmetric about the dimming element 400 on the target surface. The projection module 1000 for a large projection screen can be installed near the reverse camera module in the exact middle of the rear end of the vehicle, and the target surface can be the ground about 1 meter behind the left and right brake lights of the vehicle.

[0076] As Figure 3As shown, the dimming element 400 is a flat lens with an incident light surface 401 and an exit light surface 402 that are parallel to each other. The dimming element 400 may be coated with a beam-splitting film on the incident light surface 401. The specifications of the reflectivity and transmittance after surface coating may be: the transmittance Tabs is 30% - 70% and the reflectivity is Rabs 30% - 70% in the working wavelength range λ of 420nm - 680nm. The dimming element 400 may be coated with an anti-reflection film on the exit light surface 402. The specifications after surface coating may be: the transmittance Tabs ≥ 92% in the working wavelength range λ of 420nm - 680nm. For example, the specifications of the incident light surface 401 are: λ = 420nm - 680nm, Tabs = 40% - 50%, Rabs = 40% - 50%. The specifications of the exit light surface 402 are: λ = 420nm - 680nm, Tabs ≥ 98%. The thickness of the dimming element 400 may be 0.3mm - 1.1mm, and the area may be 10x10mm - 20x20mm, which can be calculated and determined according to the area illuminated by the field angle of the actual reflection optical path 520. The dimming element 400 may be a lens made of glass material, and its refractive index ND may be 1.52 to ensure that light is absorbed by the material as little as possible, reduce the light efficiency loss, and at the same time ensure that it will not age during long-term light irradiation, resulting in functional decline. The distance D between the center of the incident light surface of the dimming element 400 and the center of the exit light surface of the projection system 300 is 10mm - 20mm. The dimming element 400 forms a certain inclination angle θ with the optical axis of the projection system 300, and the inclination angle θ is determined by the size of the entire projection screen 500 to be projected. Specifically, reference can be made to the conditional formula of the field angle γ of the entire projection screen 500 below.

[0077] Please refer to again Figure 2 As shown, the field angle α of the reflection optical path 520 is 30°, the field angle β of the transmission optical path 510 = the field angle α of the reflection optical path, and the field angle γ of the entire projection screen 500 = 2*θ + 1 / 2(α + β). As Figure 4 As shown, the maximum projection area of the entire projection screen 500 is 1500mm*2500mm@1000mm, where 1500mm is the width, 2500mm is the length, and @1000mm is the installation height. The area between the projection pattern 511 of the transmission optical path and the projection pattern 521 of the reflection optical path in the entire projection screen 500, that is, the effective screen, is 1000*1600mm@1000mm. In this embodiment, the projection pattern 521 of the reflection optical path and the projection pattern 521 of the reflection optical path are completely radially symmetric about the dimming element 400, that is, they are exactly the same in size and shape, and the brightness and color of the two projection patterns are also the same, and they can both be white or other colors.

[0078] In some other alternative embodiments of the present application, such as Figure 5As shown in the figure, the projection module 1000 for a large projection screen includes: an illumination system 100, an image generation unit 200, a projection system 300, and a dimming element 400. Among them, the illumination system 100, the image generation unit 200, and the projection system 300 constitute the optical system 600 of the projection module. The parallel light emitted by the illumination system 100 lights up the image generation unit 200 to generate an image to be projected. The light of the image to be projected passes through the projection system 300 and is projected onto the dimming element 400. The dimming element 400 divides it into two parts. One part of the light is transmitted by the dimming element 400 to form a transmission optical path 510, and finally a projection pattern 511 of the transmission optical path is formed on one side of the target surface. The other part of the light is reflected by the dimming element 400 to form a reflection optical path 520, and finally a projection pattern 521 of the reflection optical path is formed on the other side of the target surface. The projection pattern 511 of the transmission optical path and the projection pattern 521 of the reflection optical path form a projection screen 500 that is radially symmetric about the dimming element 400 on the target surface. The projection module 1000 for a large projection screen can be installed near the reverse camera module in the exact middle of the rear end of the vehicle. The target surface can be the ground about 1 meter behind the left and right brake lights of the vehicle.

[0079] As Figure 6 shown, the dimming element 400 is a flat lens with an incident surface 401 and an exit surface 402 that are parallel to each other. The dimming element 400 can be coated with a beam-splitting film on the incident surface 401. When visible light is divided into three bands of red, green, and blue light, the beam-splitting film can choose to transmit one or two of the bands of light and reflect the remaining two or one band of light. At this time, five permutation and combination results can be formed. For example: the beam-splitting film transmits the red and green light bands and reflects the blue light band. The specifications of its reflectivity and transmittance after surface coating can be: the reflectivity Rabs ≥ 90% in the working band λ of 420 nm to 530 nm, and the transmittance Tabs ≥ 92% in the working band λ of 535 nm to 680 nm. The dimming element 400 can be coated with an anti-reflection film on the exit surface 402. The specifications of its surface coating can be: the transmittance Tabs ≥ 92% in the working band λ of 420 nm to 680 nm. For example, the specifications of the incident surface 401 are: λ = 420 nm to 530 nm, Rabs ≥ 90%; λ = 535 nm to 680 nm, Tabs ≥ 92%. The specifications of the exit surface 402 are: λ = 420 nm to 680 nm, Tabs ≥ 98%.

[0080] As Figure 7As shown, in this embodiment, the projection pattern 521 of the reflection optical path and the projection pattern 521 of the reflection optical path are completely radially symmetric with respect to the dimming element 400, that is, they are exactly the same in size and shape. The brightness and color of the two projection patterns can be different according to the bands transmitted and reflected by the dimming element 400. For example, if the red and green light bands are transmitted and the blue light band is reflected, then the projection pattern 511 of the transmission optical path is red and green, while the projection pattern 521 of the reflection optical path is blue. The brightness of the projection pattern 521 of the reflection optical path is about 1.5 times that of the projection pattern 511 of the transmission optical path, so that projections of different color patterns on the left and right can be realized.

[0081] In this embodiment, other parameters of the dimming element 400 and other parameters of the projection module 1000 and the projection screen 500 are similar to those of Figures 2 to 4 the embodiment shown, and reference can be made to the description of the embodiment shown in Figures 2 to 4 so it will not be elaborated here.

[0082] In some other alternative embodiments of the present application, as Figure 8 shown, the projection module 1000 for a large projection screen includes: an illumination system 100, an image generation unit 200, a projection system 300, and a dimming element 400. Among them, the illumination system 100, the image generation unit 200, and the projection system 300 constitute the optical system 600 of the projection module. The parallel light emitted by the illumination system 100 lights up the image generation unit 200 to generate an image to be projected. The light of the image to be projected passes through the projection system 300 and is projected onto the dimming element 400. The dimming element 400 divides it into two parts. One part of the light is transmitted by the dimming element 400 to form a transmission optical path 510, and finally a projection pattern 511 of the transmission optical path is formed on one side of the target surface. The other part of the light is reflected by the dimming element 400 to form a reflection optical path 520, and finally a projection pattern 521 of the reflection optical path is formed on the other side of the target surface. The projection pattern 511 of the transmission optical path and the projection pattern 521 of the reflection optical path form a projection screen 500 that is radially symmetric with respect to the dimming element 400 on the target surface. The projection module 1000 for a large projection screen can be installed near the reverse camera module in the exact middle of the rear end of the vehicle. The target surface can be the ground about 1 meter behind the left and right brake lights of the vehicle.

[0083] As Figure 9As shown, the dimming element 400 is a meniscus lens with a curved incident surface 401 and a curved exit surface 402, which can appropriately reduce or enlarge the size of the reflected or transmitted pattern. The dimming element 400 may be coated with a beam-splitting film on the incident surface 401. After surface coating, the specifications of the reflectivity and transmittance may be as follows: in the working wavelength band λ of 420 nm to 680 nm, the transmittance Tabs is 30% to 70%, and the reflectivity Rabs is 30% to 70%. The dimming element 400 may be coated with an anti-reflection film on the exit surface 402. After surface coating, the specifications may be as follows: in the working wavelength band λ of 420 nm to 680 nm, the transmittance Tabs ≥ 92%. For example, the specifications of the incident surface 401 are: λ = 420 nm to 680 nm, Tabs = 40% to 50%, and Rabs = 40% to 50%. The specifications of the exit surface 402 are: λ = 420 nm to 680 nm, Tabs ≥ 98%.

[0084] As Figure 10 shown, in this embodiment, the projected pattern 521 of the reflection optical path and the projected pattern 521 of the reflection optical path are not completely radially symmetric with respect to the dimming element 400, that is, they have the same shape but different sizes, and the brightness and color of the two projected patterns are also the same, and can be white or other colors. This embodiment is conducive to realizing diversified and personalized projected pattern designs.

[0085] In this embodiment, other parameters of the dimming element 400 and other parameters of the projection module 1000 and the projection screen 500 are similar to those of the Figures 2 to 4 embodiment shown, and reference may be made to the description of the embodiment shown in Figures 2 to 4 so it will not be described again here.

[0086] In some other alternative embodiments of the present application, as Figure 11As shown in the figure, the projection module 1000 for a large projection screen includes: an illumination system 100, an image generation unit 200, a projection system 300, and a dimming element 400. Among them, the illumination system 100, the image generation unit 200, and the projection system 300 form the optical system 600 of the projection module. The parallel light emitted by the illumination system 100 lights up the image generation unit 200 to generate an image to be projected. The light of the image to be projected passes through the projection system 300 and is projected onto the dimming element 400. The dimming element 400 divides it into two parts. One part of the light is transmitted by the dimming element 400 to form a transmission optical path 510, and finally a projection pattern 511 of the transmission optical path is formed on one side of the target surface. The other part of the light is reflected by the dimming element 400 to form a reflection optical path 520, and finally a projection pattern 521 of the reflection optical path is formed on the other side of the target surface. The projection pattern 511 of the transmission optical path and the projection pattern 521 of the reflection optical path form a projection screen 500 that is radially symmetric about the dimming element 400 on the target surface. The projection module 1000 for a large projection screen can be installed near the reverse camera module in the exact middle of the rear end of the vehicle. The target surface can be the ground about 1 meter behind the left and right brake lights of the vehicle.

[0087] As Figure 12 shown in the figure, the dimming element 400 is a meniscus lens with a curved incident surface 401 and a curved exit surface 402, which can appropriately reduce or enlarge the size of the reflected or transmitted pattern. The dimming element 400 can be coated with a beam-splitting film on the incident surface 401. When the visible light band is divided into three bands of red, green, and blue light, the beam-splitting film can select to transmit one or two of the bands of light and reflect the remaining two or one band of light. At this time, five permutation and combination results can be formed. For example, the beam-splitting film transmits the red and green light bands and reflects the blue light band. The specifications of the reflectivity and transmittance after coating its surface can be: the reflectivity Rabs≥90% in the working band λ of 420nm - 530nm, and the transmittance Tabs≥92% in the working band λ of 535nm - 680nm. The dimming element 400 can be coated with an anti-reflection film on the exit surface 402. The specifications after coating its surface can be: the transmittance Tabs≥92% in the working band λ of 420nm - 680nm. For example, the specifications of the incident surface 401 are: λ = 420nm - 530nm, Rabs≥90%; λ = 535nm - 680nm, Tabs≥92%. The specifications of the exit surface 402 are: λ = 420nm - 680nm, Tabs≥98%.

[0088] As Figure 13As shown, in this embodiment, the projection pattern 521 of the reflection optical path and the projection pattern 521 of the reflection optical path are not completely radially symmetric with respect to the dimming element 400, that is, they have the same shape but different sizes. The brightness and color of the two projection patterns can be different according to the bands transmitted and reflected by the dimming element 400. For example, if the red and green light bands are transmitted and the blue light band is reflected, then the projection pattern 511 of the transmission optical path is red and green, while the projection pattern 521 of the reflection optical path is blue. The brightness of the projection pattern 521 of the reflection optical path is about 1.5 times that of the projection pattern 511 of the transmission optical path, so that projections of different color patterns on the left and right can be realized. This embodiment is conducive to realizing diversified and personalized projection pattern designs.

[0089] In this embodiment, other parameters of the dimming element 400 and other parameters of the projection module 1000 and the projection screen 500 are the same as those in Figures 2 to 4 the embodiment shown, and reference can be made to the description of the embodiment shown in Figures 2 to 4 the embodiment shown, so it will not be repeated here.

[0090] In some other optional embodiments of the present application, as Figure 14 shown, the projection module 1000 for a large projection screen includes: an illumination system 100, an image generation unit 200, a projection system 300, and a dimming element 400. Among them, the illumination system 100, the image generation unit 200, and the projection system 300 constitute the optical system 600 of the projection module. The parallel light emitted by the illumination system 100 lights up the image generation unit 200 to generate an image to be projected. The light of the image to be projected passes through the projection system 300 and is projected onto the dimming element 400. The dimming element 400 divides it into two parts. One part of the light is transmitted by the dimming element 400 to form a transmission optical path 510, and finally a projection pattern 511 of the transmission optical path is formed on one side of the target surface. The other part of the light is reflected by the dimming element 400 to form a reflection optical path 520, and finally a projection pattern 521 of the reflection optical path is formed on the other side of the target surface. The projection pattern 511 of the transmission optical path and the projection pattern 521 of the reflection optical path form a projection screen 500 that is radially symmetric with respect to the dimming element 400 on the target surface. The projection module 1000 for a large projection screen can be installed near the reverse camera module in the exact middle of the rear end of the vehicle, and the target surface can be the ground about 1 meter behind the left and right brake lights of the vehicle.

[0091] As Figure 15As shown, the dimming element 400 is a wedge-shaped lens with an incident light surface 401 and an emergent light surface 402 being planes at a certain angle. It can further adjust the splitting angle based on the angle θ between the dimming element 400 and the optical axis of the projection system 300, increasing the freedom of expanding the field of view angle of the projection screen 500. The dimming element 400 can be coated with a beam-splitting film on the incident light surface 401. After surface coating, the specifications of the reflectivity and transmittance can be: the transmittance Tabs is 30% - 70% and the reflectivity Rabs is 30% - 70% in the working wavelength range λ of 420nm - 680nm. The dimming element 400 can be coated with an anti-reflection film on the emergent light surface 402. After surface coating, the specification can be: the transmittance Tabs ≥ 92% in the working wavelength range λ of 420nm - 680nm. For example, the specification of the incident light surface 401 is: λ = 420nm - 680nm, Tabs = 40% - 50%, Rabs = 40% - 50%. The specification of the emergent light surface 402 is: λ = 420nm - 680nm, Tabs ≥ 98%.

[0092] In this embodiment, other parameters of the dimming element 400 and other parameters of the projection module 1000 and the projection screen 500 are similar to those of the Figures 2 to 4 embodiment shown, and reference can be made to the description of the Figures 2 to 4 embodiment shown, so details will not be repeated here.

[0093] The embodiment of the present application also provides a vehicle on which the projection module 1000 with a large projection screen of any of the above embodiments is installed.

[0094] Optionally, the projection module 1000 with a large projection screen is installed near the reverse camera module in the exact middle at the rear end of the vehicle, for projecting reverse contour or warning patterns.

[0095] The above specific embodiments do not constitute a limitation to the protection scope of the present disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present disclosure shall be included within the protection scope of the present disclosure.

Claims

1. A projection module for a large projection screen, characterized in that, it includes: an illumination system, an image generation unit, a projection system, and a dimming element, wherein, the light emitted by the illumination system lights up the image generation unit to generate an image to be projected, and the light of the image is projected onto the dimming element through the projection system. A part of the light is transmitted by the dimming element to one side of the target surface to form a projection pattern, and another part of the light is reflected by the dimming element to the other side of the target surface to form a projection pattern. The projection patterns on both sides form a projection screen on the target surface.

2. The projection module according to claim 1, characterized in that, the proportion P of the projection pattern within the projection range of the projection system on the target surface satisfies: P≥70%.

3. The projection module according to claim 1, characterized in that, the two projection patterns are symmetric about the dimming element.

4. The projection module according to claim 1, characterized in that, the angle θ between the dimming element and the optical axis of the projection system satisfies: 25°≤θ≤65°.

5. The projection module according to claim 1, characterized in that, the length L of the projection screen satisfies: L≥1600mm, and the field of view angle FOV of the projection system satisfies: FOV≤60°.

6. The projection module according to any one of claims 1 to 5, characterized in that, the dimming element includes a beam splitter. The light projected onto the beam splitter is divided into two beams of light over the entire wavelength range. One beam of light is transmitted by the beam splitter to form the projection pattern, and the other beam of light is reflected by the beam splitter to form the projection pattern.

7. The projection module according to any one of claims 1 to 5, characterized in that, the dimming element includes a filter. The light projected onto the filter is divided into two beams of light in different wavelength bands. One beam of light is transmitted by the filter to form the projection pattern, and the other beam of light is reflected by the filter to form the projection pattern.

8. The projection module according to any one of claims 1 to 5, characterized in that, the field of view angle α of the light reflected by the dimming element, the field of view angle β of the light transmitted by the dimming element, the field of view angle γ of the projection screen, and the angle θ between the dimming element and the optical axis of the projection system satisfy: γ≥α + β + 15°, γ≤2*θ + 1 / 2(α + β) + 20°.

9. The projection module according to any one of claims 1 to 5, characterized in that, the field of view angle α of the light reflected by the dimming element and the angle θ between the dimming element and the optical axis of the projection system satisfy: 0.5*α + θ≤80°.

10. A vehicle, characterized in that, it includes: the projection module for a large projection screen according to any one of claims 1 to 9.

Images