CN118938489A - Optical system and HUD device for naked-eye 3D imaging - Google Patents

Abstract

The application provides an optical system for naked eye 3D imaging and HUD equipment, which belong to the naked eye 3D technology and comprise the following steps: an image source device, a beam splitting unit and a light path folding device; the light path folding device is used for carrying out folding processing on the second polarized light and enabling the second polarized light to pass through the light splitting unit again to be emitted to form second imaging light. According to the optical system for naked eye 3D imaging, the second polarized light is folded by the optical path folding device, so that the optical path length of the second polarized light for forming the second imaging light is larger than that of the first polarized light for forming the first imaging light, and the dual-purpose first imaging light and the second imaging light entering a viewer form a depth-of-field effect, so that the naked eye 3D effect is realized. In addition, the optical system for naked eye 3D imaging is simple in structure, and an observer can generate the effect of naked eye 3D without standing at a specific position in the observation process.

Description

Optical system for naked eye 3D imaging and HUD equipment

Technical Field

The invention relates to a naked eye 3D technology, in particular to an optical system for naked eye 3D imaging and HUD equipment.

Background

Naked eye 3D, also known as Autostereoscopy, is a technology that can achieve stereoscopic effects without the aid of external tools such as polarized glasses. The naked eye 3D technology mainly enables left and right eyes to only see specific pixel points on a screen through the structure of the screen and a special display technology, so that a vivid stereoscopic image effect is generated.

The current naked eye 3D technology is a cylindrical prism naked eye 3D technology, a cylindrical lens technology is also called a micro cylindrical lens 3D technology, and three-dimensional stereoscopic display (namely spectroscopic stereoscopic display) based on a binocular parallax principle, particularly a naked eye spectroscopic stereoscopic display technology, is beginning to be applied to HUD. The naked eye spectroscopic stereoscopic display technology, by respectively improving slightly different images for the left eye and the right eye of the observer, cheats the brain of the observer, and enables the observer to generate a 3D visual effect without wearing three-dimensional stereoscopic glasses, as shown in fig. 1, is a light barrier stereoscopic display technology, in which the display 101 (i.e., an image source) includes two types of pixel points, respectively denoted as VaR and VaL, for emitting light carrying right eye image information (hereinafter referred to as right eye light), vaL for emitting light carrying left eye image information (hereinafter referred to as left eye light), and the parallax barrier structure 102 is located on the light emitting side of the display 101, and when it is located at a certain ideal position relative to the display 101 and relative to the eyes of the observer, the right eye of the observer can almost only receive the right eye light emitted by the VaR, so that the left eye and the right eye of the observer can almost only receive the left eye light emitted by VaL, respectively see different images, and thus enable the observer to generate a visual effect of viewing 3D image.

The above-mentioned light barrier type stereoscopic display technology requires that the parallax barrier structure is located at a certain ideal position of the display and the eyes of the observer, so that the right eye of the observer can almost only receive the right eye light emitted by the VaR, and the left eye of the observer can almost only receive the left eye light emitted by VaL, i.e. the parallax barrier structure, the display and the eyes of the observer are located at a specific angle position, so that the observer can generate a visual effect of viewing the 3D image.

Disclosure of Invention

Based on the above-mentioned situation, the main objective of the present invention is to provide an optical system and HUD device for naked eye 3D imaging, so as to solve the technical problems that in the related art, the parallax barrier structure, the image source and the observer are inconvenient to be at ideal angular positions, the observer is required to stand at a specific angle to watch the display, and the naked eye 3D is inconvenient to be formed at each angle.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

In a first aspect, the present application provides an optical system for naked eye 3D imaging, comprising:

an image source device, a beam splitting unit and a light path folding device;

the image source device is used for emitting first polarized light with a first polarization direction and second polarized light with a second polarization direction, and the first polarization direction and the second polarization direction are perpendicular;

the light splitting unit is arranged in the propagation direction of the first polarized light and the second polarized light, and is used for reflecting the first polarized light and forming first imaging light so as to propagate to the eye box;

The light splitting unit is further used for allowing the second polarized light to pass through;

The optical path folding device is arranged in the propagation direction of the second polarized light transmitted through the light splitting unit, and is used for carrying out folding processing on the second polarized light transmitted through the light splitting unit, enabling the folded second polarized light to pass through the light splitting unit again and form second imaging light so as to propagate to the eye box, enabling the optical path of the second imaging light formed by the propagation of the second polarized light to be larger than the optical path of the first imaging light formed by the propagation of the first polarized light, and enabling the first imaging light and the second imaging light to form optical depth imaging.

Preferably, the optical path folding device is a reflection assembly including at least one pair of polarized light conversion units configured to be capable of mutually converting the first polarized light and the second polarized light; the at least one pair of polarized light conversion units are arranged on the propagation path of the second polarized light, one polarized light conversion unit in the pair of polarized light conversion units converts the second polarized light into first polarized light, and the other polarized light conversion unit converts the first polarized light converted into second polarized light again; the second polarized light is converted for a plurality of times by the at least one pair of polarized light conversion units after passing through the light splitting unit, then the second polarized light is formed again, and the second polarized light passes through the light splitting unit and exits to form the second imaging light.

Preferably, the first polarized light is P light, and the second polarized light is S light; the light splitting unit comprises a first surface and a second surface, the P light is reflected on the first surface after entering the first surface to form the first imaging light, and the S light is emitted through the first surface and the second surface; the polarized light conversion unit comprises a 1/4 wave plate and a reflecting mirror, wherein the 1/4 wave plate and the reflecting mirror are used for mutually converting S light and P light.

Preferably, the pair of polarized light conversion units comprises a first polarized light conversion unit and a second polarized light conversion unit, the S light passing through the light splitting unit is processed into left-handed circularly polarized light through a 1/4 wave plate of the first polarized light conversion unit, the left-handed circularly polarized light is reflected by a reflecting mirror to form right-handed circularly polarized light, the right-handed circularly polarized light is processed into P light through a 1/4 wave plate again, the P light is reflected by a second surface of the light splitting unit and then enters a 1/4 wave plate of the second polarized light conversion unit, the processed right-handed circularly polarized light is formed into right-handed circularly polarized light, the right-handed circularly polarized light is reflected by the reflecting mirror to form left-handed circularly polarized light, the left-handed circularly polarized light is processed into S light through the 1/4 wave plate again, and the S light passes through a second surface and a first surface of the light splitting unit to be emitted to form the second imaging light.

Preferably, the P-light and the S-light incident on the light splitting unit are arranged in parallel, and the first imaging light and the second imaging light emitted from the light splitting unit are parallel.

Preferably, the light splitting unit is obliquely arranged at an angle of 45 degrees relative to the polarization unit, the polarization unit is located at a first surface side of the light splitting unit, the first polarized light conversion unit is arranged at a second surface side of the light splitting unit and is parallel to the arrangement direction of the polarization unit, and the second polarized light conversion unit is arranged at a second surface of the light reflecting unit and at a first polarized light conversion unit side and is perpendicular to the arrangement direction of the first polarized light conversion unit.

Preferably, the image information carried by the first imaging light and the second imaging light are the same, and the first imaging light and the second imaging light are both adapted to be incident into the left and right eyes of the viewer at the same time.

Preferably, the image source device comprises an image source for emitting light and a polarizing unit for processing the light into the first polarized light and the second polarized light.

Preferably, the light-splitting unit is a polarizer or a light-splitting prism.

Preferably, the P light transmitted through the polarization unit forms a brewster angle reflection at the first face of the light splitting unit.

In a second aspect, the application provides a HUD device comprising the optical system for naked eye 3D imaging described above.

The beneficial effects are that:

According to the optical system for naked eye 3D imaging, the image source device emits the first polarized light and the second polarized light with the perpendicular polarization directions, the light splitting unit is arranged in the propagation directions of the first polarized light and the second polarized light, the light splitting unit can emit the first polarized light to form first imaging light and also can allow the second polarized light to penetrate, the light path folding device is arranged in the propagation direction of the second polarized light penetrating through the light splitting unit and can carry out folding processing on the second polarized light, the second polarized light can penetrate through the light splitting unit again to form second imaging light, and the second polarized light is folded through the light path folding device, so that the optical path length of the second imaging light formed by the second polarized light is larger than that of the first imaging light formed by the first polarized light, the first imaging light and the second imaging light entering left and right eyes of a viewer form depth effect, and the naked eye 3D effect is achieved. The two polarized lights do not need to enter the left eye and the right eye respectively, meanwhile, the effect of naked eye 3D can be generated in the binocular of an observer without observing at a specific angle, the structure is simple, the observer does not need to stand at a specific position in the observation process, the effect of naked eye 3D can also be generated, and the effect of naked eye 3D can be generated when the two polarized lights are incident to human eyes through separating the two polarized lights to form different optical paths.

In addition, compared with the scheme of naked eye 3D in the prior art, the distance between the human eyes and the optical system is limited because the left eye and the right eye are required to watch different imaging light, and meanwhile, the angle and the position between the parallax barrier structure and the display are required to be accurately installed; the application adopts the purpose of achieving the depth of field effect by utilizing different optical paths, so that the imaging light watched by the left eye and the right eye does not need to be distinguished, the light folding device is arranged on the propagation path of the second polarized light, and only the second polarized light can be transmitted through the light splitting unit again to complete emergent, the distance from the human eye to the optical system is not required to be limited, the naked eye 3D effect can be achieved only by the human eye receiving the imaging light, the application scene and the range of the naked eye 3D are improved, and the user experience is improved.

Other advantages of the present invention will be set forth in the description of specific technical features and solutions, by which those skilled in the art should understand the advantages that the technical features and solutions bring.

Drawings

Preferred embodiments of the optical system for naked eye 3D imaging and the HUD apparatus of the present invention will be described below with reference to the accompanying drawings. In the figure:

Fig. 1 is a schematic diagram of naked eye 3D imaging in the related art;

Fig. 2 is a schematic structural view of an optical system for naked eye 3D imaging according to a preferred embodiment of the present invention.

101. A display; 102. a parallax barrier structure;

1. A polarization unit; 2. a light splitting unit; 3. a first polarized light conversion unit; 4. a second polarized light conversion unit; 5. a 1/4 wave plate; 6. a reflecting mirror; 7. and an optical path folding device.

Detailed Description

The present invention is described below based on examples, but the present invention is not limited to only these examples. In the following detailed description of the present invention, certain specific details are set forth in order to avoid obscuring the present invention, and in order to avoid obscuring the present invention, well-known methods, procedures, flows, and components are not presented in detail.

Moreover, those of ordinary skill in the art will appreciate that the drawings are provided herein for illustrative purposes and that the drawings are not necessarily drawn to scale.

Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is, it is the meaning of "including but not limited to".

In the description of the present invention, it should be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Furthermore, in the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the related art, a naked eye type spectroscopic stereoscopic display technology is adopted to achieve a naked eye 3D effect, wherein the naked eye type spectroscopic stereoscopic display technology improves slightly different images for the left eye and the right eye of an observer respectively, cheats the brain of the observer, and enables the observer to generate the 3D visual effect without wearing three-dimensional glasses, as shown in fig. 1, the display 101 comprises two types of pixel points, which are respectively indicated as VaR and Val, the VaR is used for emitting light carrying right eye image information (hereinafter referred to as right eye light), the VaL is used for emitting light carrying left eye image information (hereinafter referred to as left eye light) on the light emitting side of the display 101, when the parallax wall structure 102 is located at an ideal position relative to the display 101 and relative to the eyes of the observer, the right eye of the observer almost only receives the right eye light emitted by the VaR, and the left eye of the observer almost only receives the left eye light emitted by VaL, so that the left eye and the right eye of the observer are respectively different, and thus one visual effect of the observer is generated. In this technology, the parallax barrier structure 102 needs to be in an ideal position relative to the display 101 and the eyes of the observer to achieve the naked eye 3D effect, and in order to overcome the problem that the observer can observe the naked eye 3D effect only at a specific angle, the present application provides an optical system for naked eye 3D imaging, which will be described in detail in the following embodiments.

Example 1

The embodiment of the application provides a specific implementation manner of an optical system for naked eye 3D imaging, as shown in fig. 2, the optical system comprises an image source device, a light splitting unit 2 and an optical path folding device, wherein the image source device is used for emitting first polarized light and second polarized light with perpendicular polarization directions, the light splitting unit 2 is arranged in the propagation directions of the first polarized light and the second polarized light, the light splitting unit 2 is used for reflecting the first polarized light and forming first imaged light so as to propagate to an eye box, the light splitting unit 2 allows the second polarized light to transmit, the optical path folding device is arranged in the propagation direction of the second polarized light transmitted through the light splitting unit 2, the optical path folding device is used for carrying out folding processing on the second polarized light transmitted through the light splitting unit 2, and enabling the second polarized light after the folding processing to pass through the light splitting unit 2 again to form second imaged light so as to propagate to the eye box, and the second polarized light is larger than the optical path of the first imaged light formed by the first polarized light due to the folding processing of the optical path folding device, so that a left-right eye and a left-eye viewer can obtain a depth-of view effect of the second imaged light, and a depth-of view effect of the first naked eye is achieved.

In this embodiment, the optical path folding device is a reflection assembly, and the reflection assembly includes at least one pair of polarized light conversion units, where the polarized light conversion units can convert first polarized light and second polarized light into each other, for example, the first polarized light can be converted into second polarized light through the polarized light conversion units and exit, the polarized light conversion units are disposed on a propagation path of the second polarized light, the second polarized light is transmitted through the light splitting unit 2 and then to one of the polarized light conversion units, the second polarized light is converted into first polarized light, the converted first polarized light is converted into second polarized light again by the other polarized light conversion unit, and the second polarized light exits from the light splitting unit 2 to form second imaging light.

Further, the first polarized light is P light, the second polarized light is S light, the light splitting unit 2 includes a first surface and a second surface, as shown in fig. 2, the first surface and the second surface are formed on the inner side and the outer side of one side surface of the light splitting unit 2, the P light is incident on the light splitting unit 2 and then reflected on the first surface to form a first imaging light, the S light is transmitted through the first surface, is converted into P light by one polarized light converting unit, then reflected on the second surface to the other polarized light converting unit, and the converted P light is converted into S light and is emitted through the light splitting unit 2 to form a second imaging light.

Specifically, as shown in fig. 2, the polarized light converting unit includes a 1/4 wave plate 5 and a reflecting mirror 6, the s light passes through the 1/4 wave plate 5 to form left circularly polarized light, the left circularly polarized light is reflected by the reflecting mirror 6 to form right circularly polarized light, and the right circularly polarized light passes through the 1/4 wave plate 5 again to form P light; similarly, the P light can form right circularly polarized light through the 1/4 wave plate 5, the right circularly polarized light is reflected by the reflecting mirror 6 to form left circularly polarized light, and the left circularly polarized light is reflected by the 1/4 wave plate 5 to form S light. In this embodiment, the pair of polarized light conversion units includes a first polarized light conversion unit and a second polarized light conversion unit, the S light transmitted through the light splitting unit 2 is first processed into left circularly polarized light by the 1/4 wave plate 5 of the first polarized unit 1, the left circularly polarized light is then reflected by the reflecting mirror 6 to form right circularly polarized light, the right circularly polarized light is then processed by the 1/4 wave plate 5 to form P light, the P light is reflected by the second surface of the light splitting unit 2 and then enters the 1/4 wave plate 5 of the second polarized unit 1, the right circularly polarized light is processed to form right circularly polarized light, the right circularly polarized light is then reflected by the reflecting mirror 6 to form left circularly polarized light, the left circularly polarized light is processed by the 1/4 wave plate 5 again to form S light, and the converted S light is completely emitted through the second surface and the first surface of the light splitting unit 2 to form second imaging light.

In other embodiments, the polarized light converting assembly may be a 1/2 wave plate and a reflecting mirror 6, where the 1/2 wave plate may directly convert P light into S light or convert S light into P light, and by setting a plurality of sets of 1/2 wave plates and reflecting mirrors 6, the S light finally entering the light splitting unit 2 can be emitted, so that the optical path of the second polarized light is larger than that of the first polarized light. Of course, the polarized light converting assembly may be other devices or components, as long as the vibration frequency of the light can be changed, so that the P light and the S light can be converted from each other, which is not limited by the present application.

In other embodiments, the light path folding device may further perform light path folding on the second polarized light using Pancake technology (folded light path technology), and Pancake technology uses a plurality of folded portions, where each portion includes a series of planar or aspheric mirrors, prisms, or lenses, etc.

In this embodiment, the P light and the S light incident on the light splitting unit 2 are parallel, the P light and the S light emitted from the light splitting unit 2 are parallel, and the first imaging light and the second imaging light emitted from the light splitting unit 2 are also parallel, so that an observer can form a 3D pattern for the P light and the S light with different optical paths at a better angle, and the viewing effect of the observer is improved.

In this embodiment, as shown in fig. 2, the light splitting unit 2 is obliquely disposed at an angle of 45 degrees with respect to the polarization unit 1, the polarization unit 1 is located at a first surface side of the light splitting unit 2, the first polarization conversion unit 3 and the second polarization conversion unit 4 are disposed at a second surface side of the light splitting unit 2, wherein the direction of disposing the first polarization conversion unit 3 is parallel to the direction of disposing the polarization unit 1, the direction of disposing the second polarization conversion unit 4 is perpendicular to the direction of disposing the first polarization conversion unit 3, the dashed line is S light in fig. 2, and it is seen that the S light is reflected again between the second polarization conversion units 4 at the second surface of the angle of 45 degrees of the light splitting unit 2 after passing through the first polarization conversion unit 3, is reflected to the light splitting unit 2 after being processed as S light, and exits from the light splitting unit 2 through the second surface.

In this embodiment, the image source device includes an image source (not shown in the drawings) for emitting light with an image, and a polarization unit 1 for processing the light into first polarized light and second polarized light, specifically, the polarization unit 1 is a polarizer.

In this embodiment, the light-splitting unit 2 is a polarizer or a light-splitting prism, and specifically, in this embodiment, a light-splitting prism is used.

In this embodiment, the P light transmitted through the polarizing unit 1 forms a brewster angle reflection on the first surface of the light splitting unit 2, and the brewster angle can enable the P light to form reflection on the first surface of the light splitting unit 2 at a specific angle when the P light is incident, so as to generate linearly polarized light, and improve visual clarity.

In this embodiment, the inner and outer sides of the inclined plane of the beam splitter prism form a first surface and a second surface, as shown in fig. 2, the P light is directly reflected on the first surface to form a first imaging light, the S light is transmitted through the first surface and the second surface, the P light is formed at the first polarized light converting unit 3 and is reflected on the second surface to form the S light at the second polarized light converting unit 4, and the converted S light is transmitted through the second surface to be emitted to form a second imaging light.

Example 2

The present embodiment provides a specific implementation manner of a HUD device, including the optical system for naked eye 3D imaging in embodiment 1, where the HUD device is applied to head-up display of an automobile.

According to the optical system for naked eye 3D imaging provided by the present example, the image source device emits the first polarized light and the second polarized light with the polarization directions perpendicular, the light splitting unit is disposed in the propagation directions of the first polarized light and the second polarized light, the light splitting unit can emit the first polarized light to form the first imaging light and can also allow the second polarized light to transmit, and the light path folding device is disposed in the propagation direction of the second polarized light transmitted through the light splitting unit, and is configured to fold the second polarized light, and enable the second polarized light to pass through the light splitting unit again to form the second imaging light, and the second polarized light is formed by the folding processing of the light path folding device, so that the optical path length of the second imaging light formed by the second polarized light is larger than the optical path length of the first imaging light formed by the first polarized light, thereby enabling the first imaging light and the second imaging light entering the left and right eyes of the viewer to form the depth effect of field, and further achieving the naked eye 3D effect. The two polarized lights do not need to enter the left eye and the right eye respectively, meanwhile, the effect of naked eye 3D can be generated in the binocular of an observer without observing at a specific angle, the structure is simple, the observer does not need to stand at a specific position in the observation process, the effect of naked eye 3D can also be generated, and the effect of naked eye 3D can be generated when the two polarized lights are incident to human eyes through separating the two polarized lights to form different optical paths.

In addition, compared with the scheme of naked eye 3D in the prior art, the distance between the human eyes and the optical system is limited because the left eye and the right eye are required to watch different imaging light, and meanwhile, the angle and the position between the parallax barrier structure and the display are required to be accurately installed; the application adopts the purpose of achieving the depth of field effect by utilizing different optical paths, so that the imaging light watched by the left eye and the right eye does not need to be distinguished, the light folding device is arranged on the propagation path of the second polarized light, and only the second polarized light can be transmitted through the light splitting unit again to complete emergent, the distance from the human eye to the optical system is not required to be limited, the naked eye 3D effect can be achieved only by the human eye receiving the imaging light, the application scene and the range of the naked eye 3D are improved, and the user experience is improved.

Those skilled in the art will appreciate that the above-described preferred embodiments can be freely combined and stacked without conflict.

It will be understood that the above-described embodiments are merely illustrative and not restrictive, and that all obvious or equivalent modifications and substitutions to the details given above may be made by those skilled in the art without departing from the underlying principles of the invention, are intended to be included within the scope of the appended claims.

Claims (10)

1. An optical system for naked eye 3D imaging, comprising: an image source device, a beam splitting unit (2) and an optical path folding device (7);

the image source device is used for emitting first polarized light with a first polarization direction and second polarized light with a second polarization direction, and the first polarization direction and the second polarization direction are perpendicular;

the light splitting unit (2) is arranged in the propagation direction of the first polarized light and the second polarized light, and the light splitting unit (2) is used for reflecting the first polarized light and forming first imaging light so as to propagate to the eye box;

the light splitting unit (2) is further configured to allow the second polarized light to pass through;

The optical path folding device (7) is arranged in the propagation direction of the second polarized light transmitted through the light splitting unit (2), the optical path folding device (7) is used for carrying out folding processing on the second polarized light transmitted through the light splitting unit (2), and enabling the folded second polarized light to pass through the light splitting unit (2) again to be emitted to form second imaging light so as to propagate to the eye box, so that the optical path length of the second imaging light formed by the second polarized light is larger than the optical path length of the first imaging light formed by the first polarized light, and the first imaging light and the second imaging light form optical depth imaging.

2. The optical system for naked eye 3D imaging according to claim 1, wherein the optical path folding device is a reflection assembly including at least a pair of polarized light conversion units configured to be capable of mutually converting the first polarized light and the second polarized light; the at least one pair of polarized light conversion units are arranged on the propagation path of the second polarized light, one polarized light conversion unit in the pair of polarized light conversion units converts the second polarized light into first polarized light, and the other polarized light conversion unit converts the first polarized light converted into second polarized light again; the second polarized light is transmitted through the light splitting unit (2), converted for a plurality of times by the at least one pair of polarized light converting units, and then formed into second polarized light again, and transmitted through the light splitting unit (2) to be emitted to form the second imaging light.

3. The optical system for naked eye 3D imaging according to claim 2, wherein the first polarized light is P light and the second polarized light is S light; the light splitting unit (2) comprises a first surface and a second surface, the P light is reflected on the first surface after entering the first surface to form the first imaging light, and the S light is emitted through the first surface and the second surface; the polarized light conversion unit comprises a 1/4 wave plate (5) and a reflecting mirror (6), wherein the 1/4 wave plate (5) and the reflecting mirror (6) are used for mutually converting S light and P light.

4. An optical system for naked eye 3D imaging according to claim 3, wherein the polarization conversion units are arranged as a pair, and include a first polarization conversion unit (3) and a second polarization conversion unit (4), S light transmitted through the light splitting unit (2) is firstly processed into left circularly polarized light by a 1/4 wave plate (5) of the first polarization conversion unit (3), the left circularly polarized light is then reflected by a reflecting mirror (6) to form right circularly polarized light, the right circularly polarized light is then processed by the 1/4 wave plate (5) to form P light, the P light is reflected by a second face of the light splitting unit (2) and then enters a 1/4 wave plate (5) of the second polarization conversion unit (4), the processed right circularly polarized light is then reflected by the reflecting mirror (6) to form left circularly polarized light, the left circularly polarized light is then processed by the 1/4 wave plate (5) again, and the S light is transmitted through the second face and the first face of the light splitting unit (2) to form the second imaged light.

5. The optical system for naked eye 3D imaging according to claim 4, characterized in that the P-light and the S-light incident on the spectroscopic unit (2) are arranged in parallel, and the first imaging light and the second imaging light emitted by the spectroscopic unit (2) are parallel.

6. The optical system for naked eye 3D imaging according to any one of claims 1-5, wherein the first imaging light and the second imaging light carry the same image information, and wherein the first imaging light and the second imaging light are both adapted to be incident into the left and right eyes of a viewer simultaneously.

7. Optical system for naked eye 3D imaging according to any of the claims 1-5, characterized in that the image source device comprises an image source for emitting light and a polarizing unit (1), the polarizing unit (1) being adapted to process light into the first and second polarized light.

8. Optical system for naked eye 3D imaging according to any of the claims 1-5, characterized in that the light splitting unit (2) is a polarizer or a light splitting prism.

9. Optical system for naked eye 3D imaging according to claim 7, characterized in that the P-light transmitted through the polarizing unit (1) forms a brewster angle reflection at the first face of the light splitting unit (2).

10. HUD device characterized in that it comprises an optical system for naked eye 3D imaging according to any of claims 1-9.