Head-up display device and vehicle

Abstract

The utility model discloses a head-up display device and a vehicle, and belongs to the technical field of head-up display. A head-up display device comprises a projection light source used for outputting a projection light beam; the diffractive optical element is arranged on the windshield; the steering optical element is arranged on a light path where the projection light source outputs the projection light beam and used for steering the projection light beam and emitting the projection light beam to the diffractive optical element, and the diffractive optical element is used for diffracting and outputting the incident projection light beam to human eyes; wherein the diffractive optical element and the steering optical element are optical elements capable of mutually compensating chromatic aberration. By introducing the steering optical element to eliminate chromatic aberration, the imaging quality of the display system can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of head-up display, and more specifically, to a head-up display device and a vehicle. Background Art

[0002] Nowadays, HUD (Head Up Display) is increasingly used in vehicle systems, which allows the human eye to focus on the road surface, and to see road conditions and driving information at the same time, thus achieving safe driving. With the continuous development of AR technology, applying AR technology to HUD has become a new trend, realizing interesting interactions between virtual images and actual road conditions during vehicle driving.

[0003] As a lightweight, high-diffraction-efficiency optical device, diffractive optical elements have good application prospects. When used in AR-HUD, diffractive optical elements are usually placed on the windshield of a car to correct the optical aberration caused by the windshield. However, due to the selectivity of diffractive optical elements to light wavelengths, chromatic aberration is serious, resulting in poor imaging quality. Utility Model Content

[0004] In view of the problems existing in the prior art, the purpose of the utility model is to provide a head-up display device, which eliminates chromatic aberration by introducing a steering optical element, thereby helping to improve the imaging quality of the display system.

[0005] In order to solve the above problems, the utility model provides a head-up display device, comprising: a projection light source, used to output a projection light beam; a diffractive optical element, wherein the diffractive optical element is arranged on a windshield; a steering optical element, wherein the steering optical element is arranged on an optical path of the projection light beam output by the projection light source, and is used to deflect the projection light beam and emit it toward the diffractive optical element, and the diffractive optical element is used to diffract the incident projection light beam and output it to a human eye; wherein the diffractive optical element and the steering optical element are optical elements that can compensate for chromatic aberration with each other.

[0006] In an optional embodiment of the present application, the diffractive optical element is a holographic optical element, and the holographic optical element is arranged in an interlayer of the windshield or on an inner surface of the windshield.

[0007] In an optional embodiment of the present application, an optical waveguide is further arranged between the projection light source and the diffractive optical element, the optical waveguide includes a substrate and a coupling-in end and a coupling-out end respectively arranged at two ends of the substrate, the projection light source is arranged on a side close to the coupling-in end, and the coupling-out end is provided with a coupling-out element.

[0008] In an optional embodiment of the present application, the outcoupling element is the steering optical element.

[0009] In an optional embodiment of the present application, a collimating lens is arranged between the projection light source and the coupling-in end.

[0010] In an optional embodiment of the present application, the steering optical element is a diffractive optical element or a prism.

[0011] In an optional embodiment of the present application, the deflecting optical element is a prism, which is used to refract the projection light beam at least twice and reflect it at least once, so as to deflect the projection light beam and emit it toward the diffractive optical element.

[0012] In an optional embodiment of the present application, at least one surface of the prism is a free-form surface.

[0013] In an optional embodiment of the present application, a reflector is arranged between the projection light source and the steering optical element, and the reflector is a plane reflector or a curved reflector.

[0014] Another aspect of the present application provides a vehicle, including a cab, wherein the cab is provided with the head-up display device as described above.

[0015] The head-up display device provided by the present application includes: a projection light source for outputting a projection light beam; a diffractive optical element, the diffractive optical element being arranged on a windshield; a steering optical element, the steering optical element being arranged on the optical path of the projection light beam outputted by the projection light source, for steering the projection light beam and emitting it toward the diffractive optical element, the diffractive optical element being used to diffract the incident projection light beam and output it to the human eye; wherein the diffractive optical element and the steering optical element are optical elements that can compensate for chromatic aberration with each other. The head-up display device provided by the present application has a steering optical element arranged between the projection light source and the diffractive optical element, the diffractive optical element and the steering optical element having opposite dispersion characteristics, and can realize chromatic aberration correction within a specific range of the three-color wavelength line width of the projection light source, thereby improving the imaging quality of the display system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the utility model or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A schematic diagram of the optical path structure of the head-up display device provided in an embodiment of the present application;

[0018] Figure 2 A schematic diagram of another optical path structure of the head-up display device provided in an embodiment of the present application;

[0019] Figure 3 A schematic diagram of another optical path structure of the head-up display device provided in an embodiment of the present application;

[0020] Figure 4 A schematic diagram of another optical path structure of the head-up display device provided in an embodiment of the present application;

[0021] Figure 5 A schematic diagram of another optical path structure of the head-up display device provided in an embodiment of the present application;

[0022] Figure 6 A schematic diagram of another optical path structure of the head-up display device provided in an embodiment of the present application;

[0023] Figure 7 A schematic diagram of another optical path structure of the head-up display device provided in an embodiment of the present application;

[0024] Figure 8 This is another schematic diagram of the optical path structure of the head-up display device provided in an embodiment of the present application.

[0025] Description of reference numerals:

[0026] 1. Projection light source; 21. Steering optical element; 22. Diffractive optical element; 3. Windshield; 4. Optical waveguide; 41. Substrate; 42. Incoupling end; 43. Outcoupling end. DETAILED DESCRIPTION

[0027] In the prior art, since the windshield of a car is generally concave, the projection light beam emitted by the projection light source will produce aberration after being reflected by the windshield, making the image unclear. As a lightweight optical device, the diffractive optical element has good wavelength selectivity, angle selectivity and high diffraction efficiency, and can record and correct the changes of the windshield concave surface to the light wavefront in advance and make timely adjustments. Therefore, setting the diffractive optical element on the windshield can well correct the optical aberration caused by the windshield and ensure clear imaging. However, since the diffractive optical element is selective to the light wavelength, the chromatic aberration is serious, which will cause poor imaging quality.

[0028] To this end, the present application provides a head-up display device that can eliminate the chromatic aberration caused by the introduction of diffractive optical elements while meeting the optical aberration correction requirements of the windshield, which is beneficial to improving the imaging quality of the display system.

[0029] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0030] See also Figure 1-8 One aspect of the present application provides a head-up display device, including a projection light source 1, for outputting a projection light beam; a diffractive optical element 22, the diffractive optical element 22 is arranged on the windshield 3; a steering optical element 21, the steering optical element 21 is arranged on the optical path of the projection light beam output by the projection light source 1, and is used to deflect the projection light beam and emit it toward the diffractive optical element 22, the diffractive optical element 22 is used to diffract the incident projection light beam and output it to the human eye; wherein the diffractive optical element 22 and the steering optical element 21 are optical elements that can compensate for chromatic aberration with each other.

[0031] In this embodiment, the diffractive optical element 22 and the steering optical element 21 have opposite dispersion characteristics, and chromatic aberration correction can be achieved within a specific range of the three-color wavelength line width of the projection light source 1, that is, the positive and negative chromatic aberrations in the diffractive optical element 22 and the steering optical element 21 are offset. How to design the dispersion parameters of the diffractive optical element 22 and the steering optical element 21 to achieve chromatic aberration correction is a well-known technology in the art and will not be elaborated on here. In some examples, the projection light source 1 can be any one of a DMD, LCD, OLED, DLP, LBS, and LCoS light source.

[0032] Further, the diffractive optical element 22 is a holographic optical element, and the holographic optical element is arranged in the interlayer of the windshield 3 or on the inner surface of the windshield 3. The process of attaching the holographic optical element to the inner surface of the windshield 3 is relatively simple. The holographic optical element is sandwiched in the windshield, which can prevent the holographic optical element from being damaged or corroded due to changes in the external environment, and has high reliability. Optionally, the holographic optical element can be a holographic film.

[0033] An optical waveguide 4 is also arranged between the projection light source 1 and the diffractive optical element 22. The optical waveguide 4 includes a substrate 41 and a coupling end 42 and a coupling end 43 respectively arranged at both ends of the substrate 41. The projection light source 1 is arranged on a side close to the coupling end 42, and a coupling element is arranged at the coupling end 43. The projection light beam emitted by the projection light source 1 enters the substrate 41 from the coupling end 42 of the optical waveguide 4, and propagates in the substrate 41 in a total reflection manner, and then the projection light beam is coupled out from the coupling end 43 to the diffractive optical element 22 or the steering optical element 21 through the coupling element. After being emitted from the projection light source 1, the projection light beam directly enters the optical waveguide 4 for propagation without passing through any turning system, so the light energy loss is small, the light brightness seen by the human eye is high, the picture is clear, and the display quality is good. Of course, a hollow tube can also be used instead of the optical waveguide 4, which can effectively reduce the volume occupied by the optical device.

[0034] In this embodiment, Figure 1-3 As shown, the side of the coupling end 42 facing the projection light source 1 is a beveled surface, and the projection light beam emitted from the projection light source 1 enters the optical waveguide 4 from the beveled surface, and the beveled surface can be a beveled surface of a plane, or a beveled surface of a curved surface or a free-form surface. The projection light beam emitted from the projection light source 1 enters the optical waveguide 4 through the beveled surface, and the projection light beam entering the optical waveguide 4 satisfies the total reflection condition, thereby reducing the energy loss of the light beam propagating in the optical waveguide 4 and improving the utilization rate of the light beam. It can be understood that the coupling end 42 can also be set not as a beveled surface, but a coupling element is set at the coupling end 42, and the projection light beam emitted by the projection light source 1 is emitted into the optical waveguide 4 from the coupling element (such as a coupling grating).

[0035] In addition, the outcoupling element in this embodiment is a deflection optical element 21, that is, the deflection optical element 21 is arranged on the outcoupling end 43, as shown in FIG. Figure 1-3 In the example shown, the steering optical element is a diffractive optical element. Of course, in other examples, the steering optical element 1 may also be an optical element such as a prism, a micro-nano optical element (meta-surface or two-dimensional material, etc.), which can compensate for the chromatic aberration with the diffractive optical element 22 on the windshield 3 and can redirect the projection light beam transmitted by total reflection in the optical waveguide 4 to be projected onto the diffractive optical element 22; Figure 1 As shown, the outcoupling end 43 is set as an oblique surface, and the steering optical element 21 is set on the oblique surface. The steering optical element 21 is a (reflective) diffraction optical element; Figure 2 As shown, the outcoupling end 43 is arranged on a partial area of ​​the bottom side of the substrate 41, and the steering optical element 21 is a (reflective) diffractive optical element; Figure 3 As shown, the outcoupling end 43 is arranged on a partial area of ​​the upper side of the substrate 41, and the deflection optical element 21 is a (transmissive) diffractive optical element.

[0036] Of course, the above-mentioned coupling element can also be an optical element with a coupling function such as a coupling grating. The projection light beam transmitted by total reflection in the optical waveguide 4 is coupled out to the steering optical element 21 through the coupling element, and then redirected by the steering optical element 21 to be projected onto the diffraction optical element 22 on the windshield 3.

[0037] In order to ensure that as much of the projection light beam emitted by the projection light source 1 as possible can enter the optical waveguide 4 , in an optional embodiment of the present application, a collimating lens is arranged between the projection light source 1 and the coupling end 42 .

[0038] The steering optical element 21 is a diffractive optical element or a prism; when the steering optical element 21 is a diffractive optical element, it can be a holographic optical element. The holographic optical element records the projection light beam by optical interference, and can reflect, diffract or transmit a specific projection light beam. The unrecorded light beam will pass through the holographic optical element. Therefore, when the external sunlight beam irradiates the holographic optical element, it will directly pass through the holographic optical element and will not enter the projection light source 1 through the optical path of the projection light beam. This can reduce the serious heating problem of the projection light source 1 caused by the backflow of sunlight, thereby ensuring the normal operation of the projection light source 1. In addition, the projection light beam output by the projection light source 1 is output after being diffracted by the steering optical element 21 and the diffractive optical element 22, which is not limited by the reflection theorem. The optical path design of the projection light beam is more flexible, and the relative positions of various optical devices are not restricted, which is conducive to the miniaturization of the head-up display device.

[0039] like Figure 7-8 As shown, the steering optical element 21 is a prism, which is used to refract the projection light beam at least twice and reflect it at least once, so that the projection light beam is redirected and emitted toward the diffractive optical element 22. By folding the light path by at least two refractions and at least one reflection, the volume occupied by the optical device can be effectively reduced. Figure 7 As shown, the prism refracts the projection light beam twice and reflects it once, and then the projection light beam is emitted toward the diffractive optical element 22; Figure 8 As shown, the prism refracts the projection light beam twice and reflects it three times before emitting it toward the diffractive optical element 22. Figure 7 The embodiment shown can further fold the optical path, and Figure 8 In the embodiment shown, at least one surface of the prism is a free-form surface, which can improve the degree of freedom of optical path design. In addition, a diffractive optical element or a holographic optical element can be arranged on one or more surfaces of the prism in combination with practical applications.

[0040] like Figure 4-6 As shown, a reflector is arranged between the projection light source 1 and the steering optical element 21. The reflector is a plane reflector or a curved reflector. The light path is folded by the arrangement of the reflector to reduce the volume occupied by the optical device. Figure 4As shown, a plane reflector and a collimating lens are arranged between the projection light source 1 and the steering optical element 21, and the steering optical element 21 is a (reflective) diffraction optical element; Figure 5 As shown, a curved reflector is arranged between the projection light source 1 and the steering optical element 21, and the curved reflector can magnify the image. The steering optical element 21 is a (reflective) diffraction optical element; Figure 6 As shown, a curved reflector is arranged between the projection light source 1 and the deflection optical element 21, and the deflection optical element 21 is a (transmissive) diffraction optical element.

[0041] In summary, in the head-up display device of the present application, a steering optical element 21 is provided between the projection light source 1 and the diffractive optical element 22 to eliminate chromatic aberration, which helps to improve the imaging quality of the display system.

[0042] Another aspect of the present application provides a vehicle, including a cab, in which the head-up display device as described above is arranged, and a windshield 3 is arranged at the front of the cab. After the projection light beam is projected onto the diffractive optical element 22 on the windshield 3, it is diffracted into the human eye and forms a positive virtual image. The human eye can see the real scene outside the vehicle through the windshield 3, and the virtual image is integrated with the real scene outside the vehicle, and the two are superimposed to achieve an augmented reality effect. Since the vehicle includes all embodiments of the above-mentioned head-up display device, it has at least the beneficial effects brought by all the above-mentioned embodiments, which will not be repeated here one by one.

[0043] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "includes", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment comprising a series of elements are inherent to the elements. In the absence of more restrictions, the elements limited by the sentence "comprising one..." do not exclude the presence of other identical elements in the process, method, article or equipment comprising the elements. In addition, the above-mentioned technical solution provided in the embodiment of the present application is consistent with the corresponding technical solution in the prior art in principle, and the part is not described in detail, so as to avoid too much redundancy.

[0044] This article uses specific examples to illustrate the principles and implementation methods of the utility model. The above examples are only used to help understand the method and core ideas of the utility model. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the utility model, the utility model can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.

Claims

1. A head-up display device, characterized in that: include: A projection light source (1), used for outputting a projection light beam; A diffractive optical element (22), wherein the diffractive optical element (22) is arranged on the windshield (3); a steering optical element (21), the steering optical element (21) being arranged on the optical path of the projection light beam output by the projection light source (1) and being used to redirect the projection light beam and emit it toward the diffractive optical element (22), the diffractive optical element (22) being used to diffract the incident projection light beam and output it to a human eye; Wherein, the diffractive optical element (22) and the steering optical element (21) are optical elements that can compensate for chromatic aberration of each other.

2. A head-up display device according to claim 1, characterized in that: The diffractive optical element (22) is a holographic optical element, and the holographic optical element is arranged in the interlayer of the windshield (3) or on the inner surface of the windshield (3).

3. A head-up display device according to claim 1, characterized in that: An optical waveguide (4) is further arranged between the projection light source (1) and the diffractive optical element (22), the optical waveguide (4) comprising a substrate (41) and a coupling-in end (42) and a coupling-out end (43) respectively arranged at two ends of the substrate (41), the projection light source (1) is arranged on a side close to the coupling-in end (42), and the coupling-out end (43) is provided with a coupling-out element.

4. A head-up display device according to claim 3, characterized in that: The outcoupling element is the deflection optical element (21).

5. A head-up display device according to claim 3, characterized in that: A collimating lens is provided between the projection light source (1) and the coupling-in end (42).

6. A head-up display device according to claim 1, characterized in that: The deflection optical element (21) is a diffractive optical element or a prism.

7. A head-up display device according to claim 6, characterized in that: The deflection optical element (21) is a prism, and is used to refract the projection light beam at least twice and reflect it at least once, so that the projection light beam is deflected and emitted toward the diffractive optical element (22).

8. The head-up display device according to claim 6, characterized in that: At least one surface of the prism is a free-form surface.

9. The head-up display device according to claim 1, characterized in that: A reflector is provided between the projection light source (1) and the steering optical element (21), and the reflector is a plane reflector or a curved reflector.

10. A vehicle, characterized in that: It comprises a cab, in which is arranged a head-up display device as claimed in any one of claims 1 to 9.

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