Projection system and head-up display

Abstract

The invention relates to a projection system and a head-up display. A projection system includes: - a laser beam scanner (22'', 22'''), which has an IR laser light source 14IR for generating an IR light beam and wherein the laser beam scanner (22'', 22''') is designed to generate variable IR illumination patterns (PME) on the basis of the IR light beam, - a projection surface (210, 211), onto which the IR illumination patterns (PME) can be projected, - an optical detection device (111) for optically detecting the variable IR illumination patterns on the projection surface (210, 211), and - a computer unit (52) which is designed to control the laser beam scanner (22'', 22''') in such a way that it generates the variable IR illumination patterns (PME) and projects them onto the projection surface (210, 211), and wherein the computer unit (52) is designed to evaluate the IR illumination patterns (PMR) detected by the optical detection device (11) on the projection surface (210, 211).

Description

[0001] 202405042

[0002] 1

[0003] Projection system and head-up display

[0004] The present invention relates to a projection system and a head-up display. Such projection systems are used, for example, in a head-up display to generate a virtual image on the windshield or to project it onto other windows or surfaces of a motor vehicle. A head-up display, also known as a HUD, is a display system in which the viewer can maintain their line of sight because the displayed content is projected into their field of vision. While such systems were originally used primarily in aviation due to their complexity and cost, they are now also being mass-produced in the automotive industry.

[0005] Head-up displays generally consist of an image-generating unit (PGU), an optical unit, and a mirror unit. The image-generating unit creates the image, using at least one display element. Modern head-up displays typically use displays or scanning systems for image generation. Displays can be, for example, LCDs (LC: Liquid Crystal), p-LED displays (LED: Light Emitting Diode), LCoS displays (LCoS: Liquid Crystal on Silicon), or DMD systems (DMD: Digital Micromirror Device). A laser scanning system is an example of a scanning system. The optical unit directs the image onto the mirror unit. The mirror unit is a partially reflective, translucent disc.The viewer thus sees the content displayed by the imaging unit as a virtual image and simultaneously the real world behind the glass. In automotive applications, the windshield often serves as the mirror unit, its curved shape being taken into account in the display, for example, by pre-distorting the image displayed by the imaging unit. Through the interaction of the optical unit and the mirror unit, the virtual image is a magnified and distorted representation of the image generated by the imaging unit. 202405042.

[0006] 2

[0007] Projection systems generally consist of a projector with a picture generating unit (PGU) and a projection surface on which a real image is visible. The projection surface can be a transparent window pane of a vehicle or an opaque projection surface, such as one mounted on a vehicle's dashboard. The picture generating unit creates the image, using at least one display element. Modern projectors typically use displays or scanning systems for image generation. Displays can include, for example, LCDs (Liquid Crystal), p-LED displays (Light Emitting Diode), LCoS displays (Liquid Crystal on Silicon), or DMD systems (Digital Micromirror Devices).An example of a scanning system is a laser beam scanner (often abbreviated as LBS). In this system, a laser beam modulated with image information is guided across the projection surface. This can be done, for example, in a line grid. If the projection surface has a diffuser, the image drawn by the laser beam can be seen by a viewer. Since the laser beam has a small angular spread (small aperture angle), the light coming from the diffuser is also generally limited to a specific angular range. This depends on the diffuser's scattering properties. If the diffuser scatters over a large angular range, then less light reaches the viewer's eye than with a diffuser that has a small angular range. For energy-saving reasons, a diffuser that scatters over a relatively small angular range is therefore usually used.This also benefits the brightness of the image, which can be achieved with the given, usually quite limited, projector power. The smaller the angle of dispersion of the diffuser, the greater the perceived brightness of the image.

[0008] The diffuser can, for example, be a scattering, possibly backscattering, and transparent disc. The viewer then sees the content displayed by the imaging unit as a virtual image and simultaneously the 202405042

[0009] 3. The real world behind this glass. In the automotive sector, a side window or the rear window, another transparent or reflective surface, or even an opaque surface, such as the dashboard or the headliner, often serves as the projection surface. Its curved shape is taken into account in the display, for example by pre-distorting the image displayed by the imaging unit.

[0010] The viewer can only perceive the virtual image of a head-up display or the real image emanating from a diffuser from the position of the so-called eyebox. The eyebox is defined as an area whose height and width correspond to a theoretical viewing window. The size of the eyebox depends on the angle of incidence of the light coming from the display element or the diffuser. As long as the viewer's eye is within the eyebox, all elements of the virtual or real image are visible. If, however, the eye is outside the eyebox, the virtual or real image is only partially visible or not visible at all. Therefore, the larger the eyebox, the less restricted the viewer is in their choice of seating position.

[0011] The optical unit of a head-up display typically comprises several mirrors to minimize the required installation space. Light emitted from the imaging unit is reflected by a folding mirror onto a curved mirror, which then reflects it towards the windshield. Currently used curved mirrors are essentially flat plates with a high degree of curvature, tailored to the desired optical function.

[0012] In laser beam scanner (LBS) systems, light from RGB color laser diodes is scanned across the display area by a scanner that, for example, incorporates oscillating MEMS mirrors (MEMS: micro-electro-mechanical system). The image is then generated on the display area by modulating the power of the color laser diodes synchronously with the movement of the mirrors. Compared to LCD-based display solutions, laser scanning systems are characterized by less complex optics and higher resolution.

[0013] 4

[0014] Energy efficiency and lower cooling requirements are advantages. As an alternative to RGB color laser diodes, a short-wavelength laser can also be used to scan an RGB wavelength converter in a suitable intermediate image plane.

[0015] Laser beam scanner systems can project images onto a variety of surfaces. For example, in a vehicle, images can be projected onto surfaces such as the dashboard, ceiling, or windows.

[0016] With coherent light, such as that emitted by a laser light source, unwanted speckle patterns often appear, which should be reduced or eliminated to achieve a good image. Speckle patterns, light granulation, laser granulation, or simply speckle, refer to the granular interference phenomena that can be observed, for example, when optically rough object surfaces (unevenness on the order of the wavelength) are illuminated with sufficient coherence. In more ordered structures, such as lens arrays, the interfering interference effects can also exhibit a higher degree of order. Here, we use the term speckle or speckle pattern more broadly to include such effects as well.

[0017] The term "speck," which refers to both a single spot of light and the entire interference pattern, is derived from the English word "speckle." Depending on the imaging system used, the predominantly English-language literature also distinguishes between "subjective speckle" and "objective speckle": If the speckle is projected directly onto a screen without the aid of a lens or other optical devices, it is called objective speckle. In contrast, subjective speckle refers to the imaging of the interference pattern using a lens or more complex optical systems. This includes the human eye.

[0018] In known designs, the MEMS mirror of the laser beam scanner is a flat element which is connected to the surrounding structure via thin elements 202405042

[0019] 5 is connected and is stimulated to vibrate via other elements, such as piezo elements.

[0020] The oscillating MEMS mirror reflects the incoming collimated, modulated laser beam and directs it through a subsequent projection optic to focus the beam and create the desired pixel at the desired distance. However, there are also variants with a convergent modulated laser beam.

[0021] Cabin-sensing solutions for vehicles are also known from the prior art, featuring an infrared camera and infrared illumination with IR LEDs. The IR LEDs can be arranged in various positions within the cockpit or vehicle interior. Infrared illumination is particularly necessary in night and twilight conditions.

[0022] Methods for determining spatial geometries by evaluating the distortion of imprinted geometric patterns in the illumination of a scene and / or object are also well known. An example of this is structured light reflectometry, which is used, among other things, in the testing of components such as mirrors.

[0023] It is also known to use stripe projectors, which project a striped pattern onto an object to measure 3D shapes.

[0024] Projectors with imaging optics are used to create the striped pattern; these are relatively large, and the striped pattern must be refocused depending on the distance of the object.

[0025] Therefore, a system that improves upon the aforementioned known systems is desired.

[0026] According to a first aspect of the present invention, a projection system according to the invention for a vehicle comprises: 202405042

[0027] 6

[0028] - a laser beam scanner comprising an infrared laser light source (IR: infrared) for generating an IR light beam and wherein the laser beam scanner is designed to generate variable IR illumination patterns based on the IR light beam,

[0029] - a projection surface onto which the IR illumination patterns can be projected,

[0030] - an optical detection device for optically detecting the variable IR illumination patterns on the projection surface, and

[0031] A computer unit is configured to control the laser beam scanner so that it generates variable IR illumination patterns and projects them onto the projection surface. This computer unit is also configured to evaluate the IR illumination patterns captured by the optical detection device on the projection surface. A laser beam scanner can be designed to be very compact and has small dimensions. Furthermore, a projected image, in this case an illumination pattern, generated by a laser beam scanner is sharp at any distance. Therefore, the complex refocusing and large imaging optics required by prior art are unnecessary. Many different patterns, such as stripe, tile, and / or dot patterns, can be used as variable IR illumination patterns.The laser beam scanner can generate illumination patterns, such as stripes and / or points at arbitrary intervals, thus contributing to variable IR illumination patterns. Any pattern suitable for measuring 3D shapes or for 3D reconstruction can be used as IR illumination pattern. The ease with which IR illumination patterns can be varied using a laser beam scanner, controlled by a computer unit (e.g., an algorithm), allows the projection system to be used very simply and efficiently for 3D reconstruction. "Variable" in this context can be understood in the broadest sense as non-static. In addition to the ability to easily change illumination patterns, the LBS offers, for example, the possibility of...Varying geometric distances between individual illumination patterns, such as dot and / or stripe patterns, also allows the IR illumination pattern to have temporally independent individual components. For example, each individual point of a dot pattern can be given an independent temporal component 202405042.

[0032] 7. This allows for an overall improvement and significant simplification of the evaluation. The projection system described above thus offers considerable advantages over projection systems that use static lighting patterns.

[0033] The analysis used to reconstruct a 3D scene can, for example, be used to monitor a vehicle interior. Specifically, it can be used to enable a 3D reconstruction of the position, pose, or movement of a passenger, such as the driver and / or front passenger. The information gathered can then be used for further purposes, such as authorization functions and / or monitoring the driver's condition, including fatigue, health, fitness to drive, mood, etc.

[0034] The projection system allows for targeted illumination of specific areas. Illumination and the acquisition of a projection surface can be achieved directly or indirectly via a reflective surface. Overall, by simply generating and projecting variable IR illumination patterns, a wide variety of patterns can be easily created and captured on a projection surface. This eliminates ambiguities in reflectometry and thus leads to a more reliable 3D measurement of the vehicle interior. Any object suitable for reconstructing a 3D scene can serve as a projection surface. For example, suitable projection surfaces within a vehicle interior include, in particular, vehicle occupants, preferably specific body parts such as the torso, head, face, and / or hands of the driver, front passenger, and / or other passengers.It goes without saying that other objects within vehicle interiors can also be considered as projection surfaces, which can be used for the reconstruction of a 3D scene, such as windows, seats, console surfaces, the headliner, footwells, etc.

[0035] It is understood that the optical detection device is designed to detect IR wavelengths. For example, an IR camera or other IR sensor, or several IR sensors, can be used, which are suitable for 202405042.

[0036] 8

[0037] to capture IR projection patterns onto corresponding projection surfaces. It is understood that the computing unit can then reconstruct a 3D scene, for example from distorted IR illumination patterns, based on appropriate algorithms.

[0038] If the projection system has at least one reflective surface, preferably a glass surface, such as a front, side, and / or rear window of a vehicle, which reflects the projected variable IR illumination patterns toward the projection surface, indirect lighting can be utilized. This allows, for example, a laser beam scanner to be positioned in the front of a vehicle while illuminating areas with variable IR illumination patterns, such as the rear of the vehicle, which would otherwise be shaded. This enables the monitoring and / or reconstruction of a 3D scene of areas that would normally require a separate device for the rear. This allows the efficiency of such systems to be increased with simple means.

[0039] If the projection system has at least one reflective surface, preferably a glass surface, such as a front, side, and / or rear window of a vehicle, which reflects the variable IR illumination patterns projected onto the projection surface towards the optical detection device, indirect detection of projection surfaces onto which variable IR illumination patterns are projected is possible. This allows, for example, the detection of areas within a vehicle, i.e., projection surfaces located, for instance, in the rear of the vehicle, which would otherwise be shaded and therefore could not be detected without a separate optical detection device. This enables the monitoring and / or reconstruction of a 3D scene of areas for which a separate device would normally be required.

[0040] This allows the efficiency of such systems to be increased with simple means. It is understood that the reflective surface makes the projection surface visible to the optical detection device through the reflection of light, thus enabling indirect detection. 202405042

[0041] 9

[0042] If the projection system has multiple laser beam scanners, a larger area of ​​a space, such as the interior of a vehicle, can be covered, and areas that are obscured and cannot be captured by a single projection device can be illuminated with an IR illumination pattern. Multiple laser beam scanners allow several different IR illumination patterns to be projected onto projection surfaces simultaneously, thus accelerating the reconstruction of a 3D scene. For example, each individual laser beam scanner can be controlled by the computer unit with a different frequency or a different time delay, so that the different illumination patterns are temporally distinct and can therefore be more easily differentiated during capture and analysis. The efficiency of a system with multiple laser beam scanners can be further increased by using a reflector to capture the light from a reflective surface, such as a window.is used on glass surfaces, such as glass panes.

[0043] When the laser beam scanner is positioned below the vehicle's windshield, the IR illumination pattern is projected by reflection off the windshield. This has the advantage that the upper body, head, and / or face of a driver and / or passenger can be illuminated with variable IR patterns without objects such as steering wheels obstructing the beam path. This allows the IR illumination beam to be used, for example, for driver and passenger monitoring, and the laser beam scanner can be easily concealed from the passenger's view.

[0044] If the optical detection device is positioned below the vehicle's windshield, the variable IR illumination patterns on the projection surface are detected by the optical detection device through reflection off the windshield. This has the advantage that variable IR illumination patterns projected onto the upper body and / or head and / or face of a driver and / or passenger can be detected by the optical detection device without, for example, steering wheels obstructing the beam path. This allows for [202405042]

[0045] 10. Simply hide the optical detection device so that it is not visible to a passenger and use it, for example, for monitoring the driver and passenger.

[0046] If both the laser beam scanner and the optical detection device are located below the windshield of the vehicle, and indirect illumination and detection are achieved via reflection off the windshield, particularly good opportunities arise for the efficient 3D reconstruction of the position and pose or movement of a driver and / or passenger.

[0047] When the laser beam scanner is part of a head-up display (HUD), the projection of the IR illumination pattern occurs through reflection off a reflective surface, such as the windshield or a retroreflector, which can be part of a windshield root display, also known as a scenic view display. This has the advantage that the upper body and / or head and / or face of a driver and / or passenger can be illuminated with variable IR illumination patterns without, for example, steering wheels obstructing the beam path. This allows the IR illumination beam to be used, for example, for driver and passenger monitoring, and the laser beam scanner can be easily concealed within the head-up display, out of sight of the passenger.

[0048] If the optical detection device is part of a head-up display, it detects the variable IR illumination patterns on the projection surface by reflecting them off a reflective surface, such as the windshield or a retroreflector, which can be part of a windshield root display, also known as a scenic view display. This has the advantage that variable IR illumination patterns projected onto the upper body, head, and / or face of a driver and / or passenger can be detected by the optical detection device without, for example, steering wheels obstructing the beam path. This allows the optical detection device to be easily concealed from passengers and used, for example, for driver and passenger monitoring. 202405042

[0049] 11

[0050] If both the laser beam scanner and the optical detection device are part of a head-up display, and thus indirect illumination and detection via reflection on a reflective surface, e.g., the windshield or a retroreflector, which can be part of a windshield root display, also known as a scenic view display, takes place, particularly good possibilities arise for the efficient 3D reconstruction of the position and pose or movement of a driver and / or passenger.

[0051] If the laser beam scanner, in addition to the IR laser light source, has RGB laser light sources for generating a projected image on a projection surface, image generation using the RGB laser light sources and the generation and projection of an IR illumination pattern can occur simultaneously. For example, such a laser beam scanner can be used as part of a HUD to simultaneously illuminate a driver's head, as a projection surface, with an IR light beam for driver observation, and generate an image on a windshield, also as a projection surface, using the RGB laser light sources.

[0052] The following describes a further aspect of the invention. It is understood that features and advantages mentioned for the previous aspect can be advantageously used for the aspect mentioned below, and vice versa.

[0053] According to another aspect, a head-up display system has:

[0054] - a laser beam scanner arranged in the head-up display, which has an IR laser light source for generating an IR light beam, wherein the laser beam scanner is designed to generate variable IR illumination patterns based on the IR light beam,

[0055] - a reflective surface which is arranged and designed to reflect variable IR lighting patterns into the interior of a vehicle, 202405042

[0056] 12

[0057] - an optical detection device for optically detecting the variable IR illumination patterns on projection surfaces inside the vehicle's interior, and

[0058] - a computing unit which is configured to control the laser beam scanner so that it projects the variable IR illumination patterns onto the projection surface and wherein the computing unit is configured to evaluate the IR illumination patterns detected by the optical detection device.

[0059] It goes without saying that the HUD can normally generate an image, for example, an RGB image, which can be perceived by a driver within an eyebox. Additionally, the HUD features a laser beam scanner that generates the IR illumination pattern, thus enabling simultaneous image generation and vehicle interior monitoring in conjunction with the optical detection device and the computer unit. The HUD's image generation can be conventional or based on an RGB laser beam scanner. In other words, such a HUD offers variable IR illumination of an IR pattern via the HUD optics in addition to image generation. The reflective surface can be, for example, the windshield or a retroreflector, which can be part of a windshield root display, also known as a scenic view display. The HUD can then be a so-called scenic view HUD.

[0060] If the optical detection device is located in the head-up display, indirect monitoring of the vehicle interior, e.g. driver observation, can be used via the reflective surface, e.g. the windshield, thus utilizing a clear field of vision, e.g. of a driver and / or passenger.

[0061] According to yet another aspect, a head-up display system has:

[0062] - a previously described projection system, 202405042

[0063] 13

[0064] - a reflective surface which is arranged and designed to reflect the variable IR illumination patterns generated by the projection system into the interior of a vehicle,

[0065] - an optical detection device for optically detecting the variable IR illumination patterns on projection surfaces inside the vehicle's interior, and

[0066] - a computing unit which is configured to control the laser beam scanner so that it projects the variable IR illumination patterns onto the projection surface and wherein the computing unit is configured to evaluate the IR illumination patterns detected by the optical detection device.

[0067] Further details of the invention and its advantages can also be found in the following description of the figures. These show

[0068] Fig. 1 schematically shows a head-up display;

[0069] Fig. 2 schematically shows an imaging unit;

[0070] Fig. 3 schematically shows another imaging unit

[0071] Fig. 4 schematically shows an embodiment of an imaging unit which can be used as part of a projection system according to the invention;

[0072] Fig. 5 schematically shows another embodiment of an imaging unit which can be used as part of a projection system according to the invention;

[0073] Fig. 6 schematically shows a projection system;

[0074] Fig. 7 schematically shows another projection system;

[0075] Fig. 8 schematically shows an embodiment of a projection system according to the invention; and

[0076] Fig. 9 schematically shows another embodiment of a projection system according to the invention.

[0077] Character description

[0078] To better understand the principles of the present invention, embodiments of the invention are explained in more detail below with reference to the figures. The same reference numerals in the figures denote identical or 202405042

[0079] Fourteen identical elements are used and are not necessarily described again for each figure. It is understood that the invention is not limited to the embodiments shown and that the described features can also be combined or modified without leaving the scope of protection of the invention as defined in the appended claims.

[0080] Fig. 1 schematically shows a head-up display for a vehicle as an example of an image generation system 1. The head-up display comprises an imaging unit 2, an optical unit 3, and a mirror unit 4. A beam of light SB1 originates from a projection surface 21 and is reflected by a first mirror 31 onto a curved mirror 32, which reflects it towards the mirror unit 4. The mirror unit 4 is represented here as the windshield 41 of the vehicle. From there, the beam of light SB2 travels towards the eye 61 of a viewer.

[0081] The viewer sees a virtual image VB, which is located outside the vehicle, above the hood or even in front of the vehicle. Through the interaction of optical unit 3 and mirror unit 4, the virtual image VB is a magnified representation of the image coming from the projection surface 21. Here, a speed limit, the current vehicle speed, and navigation instructions are symbolically displayed. As long as the eye 61 is within the eyebox 62, indicated by a rectangle, all elements of the virtual image are visible to the eye 61. If the eye 61 is outside the eyebox 62, the virtual image VB is only partially visible or not visible at all. The larger the eyebox 62, the less restricted the viewer is in choosing their seating position.The curvature of the curved mirror 32 is adapted to the curvature of the windshield 41 and ensures that the image distortion is as stable as possible across the entire eyebox 62. The curved mirror 32 is rotatably mounted by means of a bearing 321. The resulting rotation of the curved mirror 32 allows the eyebox 62 to be moved and thus its position to be adjusted to the position of the eye 61. The first mirror 31 serves to ensure that the path traveled by the beam SB1 is 202405042.

[0082] The distance between the projection surface 21 and the curved mirror 32 is 15, yet the optical unit 3 remains compact. The optical unit 3 is separated from its surroundings by a transparent cover 33. This protects the optical elements of the optical unit 3 from, for example, dust present in the vehicle's interior. A glare shield 34 serves to reliably absorb light reflected across the interface of the cover 33, preventing glare for the viewer. In addition to sunlight SL, light from another ambient light source 64 can also reach the projection surface 21.

[0083] Fig. 2 schematically shows an imaging unit 2 with light sources 14R, 14G, 14B that emit coherent light. The figure shows a controllable mirror unit 73 within the imaging unit 2, which acts as a display element 11. The mirror unit 73 consists, for example, of a two-dimensional arrangement of micromirrors, each of which is positioned in one of two possible positions when controlled. A light beam LB incident on the unit is thus modulated in a pixel grid to generate the virtual image VB. This is a DMD (Digital Display Device). According to another variant, the controllable mirror unit 73 consists of a mirror adjustable about several axes, which is controlled such that an incident laser beam is reflected according to a two-dimensional grid, thereby generating the virtual image VB.

[0084] The light beam LB, which strikes the micromirrors of mirror unit 73, or the laser beam that falls on the mirror adjustable about several axes, originates from the light sources 14R, 14G, 14B. The light sources 14R, 14G, 14B are indicated here as schematic boxes. They can be designed as conventional light sources, for example as light-emitting diodes (LEDs), or as laser light sources.

[0085] Fig. 3 shows another imaging unit 2. The light sources 14R, 14G, 14B are designed as laser diodes. The light emitted by each of them is collimated, indicated here by means of lenses 151. By means of a mirror 161 or by means of two dichroics 162, 163, the light emitted by the three light sources is combined in a common direction of propagation. It passes through a lens, which here is 202405042

[0086] Figure 16 schematically represents an illumination optic 155. The light is then deflected by means of the mirror unit 73, which acts as an image transmitter 11, according to the image to be displayed. It then passes onto a lens, which here schematically represents a projection optic 156. It then passes onto a diffuser 172 arranged in the projection surface 21 of the projection optic 156. After the diffuser 172, the light continues as a beam SB1.

[0087] Fig. 4 shows an embodiment of an imaging unit 200, which can be used as part of a projection system according to the invention. It comprises only an IR laser light source 14IR, which generates IR light. The light emitted by the IR laser light source 14IR is directed by means of a mirror 164 towards a lens, which here schematically represents an illumination optic 155. It is then deflected by means of the mirror unit 73 as an image transmitter 11 according to an image to be displayed, here an IR projection pattern. It then passes onto a lens, which here schematically represents a projection optic 156, and subsequently onto a projection surface 210. A computer unit, not shown here, controls the IR laser light source 14IR and the IR illumination pattern generated by the imaging unit 200. For example, the computer unit can control the mirror unit or the projection optic 155 via an algorithm.The image generator is instructed to produce a stripe, tile, or dot pattern as an IR illumination pattern. The processing unit can also control a temporal component, such as a frequency, used to generate the IR illumination pattern, for example, via an algorithm. The processing unit, which is not shown here, controls the variable IR illumination patterns so that, for example, different IR illumination patterns are generated at specific time intervals and leave the image generator 200 to be projected onto a projection surface 21.

[0088] Fig. 5 shows a further embodiment of an imaging unit 201, which can be used as part of a projection system according to the invention. In addition to the light sources 14R, 14G, 14B, which are used to generate a regular RGB projection image, an IR laser light source 14IR is used, which generates IR light. The light emitted by the three RGB light sources 14R, 14G, 14B is focused into a common image by means of three dichroic lenses 162, 163, 165.

[0089] 17

[0090] The direction of propagation is combined. It passes through a lens, which here schematically represents an illumination optic 155. It is then deflected by means of the mirror unit 73 as an image transmitter 11 according to an image to be displayed. It then reaches a lens, which here schematically represents a projection optic 156. It then reaches a projection surface 211. The light emitted by the IR light source 14IR is guided by means of a mirror 164 into the same beam path as that of the RGB light sources. The IR light emitted by the IR laser light source 14IR then travels the same path as the RGB light of the three other light sources. By means of the mirror unit 73 as image transmitter 11, the IR light is deflected into an IR illumination pattern, e.g. a stripe, tile, or dot pattern, as the image to be displayed. A computer unit, not shown here, controls the IR laser light source 14IR and the three other light sources 14R, 14G, 14B.The computer unit, which is not shown in detail here, controls the image generator 11 to generate variable IR illumination patterns, so that, for example, different IR illumination patterns are generated at specific time intervals and leave the image generator 201 to be projected onto a projection surface 21.

[0091] Fig. 6 schematically shows a projection system with a laser beam scanner 220 or imaging unit 200 and a projection surface 210. The beam generator 140 produces a modulated collimated light beam LBM. The beam generator 140 contains, for example, the IR laser light source 14IR, lens 151, mirror 164, illumination optics 155, and electronic control elements, which are not shown in this figure. The modulated light beam LBM is reflected by the mirror unit 73. The reflected light beam LBR passes through a projection optic 156 and reaches the projection surface 210. Due to the modulation, the light beam LBM carries image information that is synchronized with a movement of the mirror unit 73, so that the image to be displayed, here an IR illumination pattern, is formed on the projection surface 210 when the reflected light beam LBR is moved.

[0092] Fig. 7 schematically shows a projection system comprising a projection device as the imaging unit 2, here a laser beam scanner 22 (LBS: laser beam scanner), which is installed inside a vehicle 100. The 202405042

[0093] 18

[0094] LBS 22 is shown, by way of example, mounted on a rearview mirror of vehicle 100. The LBS 22 projects an image onto the instrument panel, which serves here as the projection surface 21. The projection is indicated here as a direction and speed indication. A computing unit 52 executes an algorithm that controls the LBS 22 to generate the desired image at the desired location. Since the instrument panel is not a flat surface but a three-dimensionally curved surface, the projection surface 21 is also curved accordingly, and the computing unit takes this curvature into account when controlling the LBS 22. Another LBS 22' is shown, by way of example, mounted on the rearview mirror of the vehicle. This LBS 22' is aligned with a side window, which forms its projection surface 21'. A circular diffuser 172 is mounted on the side window.The laser light coming from the LBS 22' is scattered by the diffuser 172 into a limited angular range. Depending on the scattering properties of the diffuser 172, a real image is visible both from inside the vehicle and from outside the vehicle, as long as the viewer's eye is within the corresponding angular range, i.e., within the eyebox.

[0095] Fig. 8 schematically shows an embodiment of a projection system according to the invention, which includes a projection device with an imaging unit 201 from Fig. 5, here LBS 22". The LBS 22" is arranged such that it is directed both at the head of the driver 10, which here forms the projection surface 211, and at a side window, which forms the projection surface 21T. For example, the LBS 22" could be arranged and aligned accordingly on a headliner or on an A-pillar of the vehicle 100. The LBS 22" uses the RGB light sources to generate a flower as a projection image on the projection surface 211', i.e., the side window, controlled by a computer unit 52, which is operationally coupled to the LBS 22".The computer unit 52 also controls the IR laser light source 14IR and, by appropriately controlling the mirror 73, generates variable IR illumination patterns PME, shown here as an example of a dot pattern, on the driver's head 10, i.e., the projection surface 211. The variable patterns are detected by an optical detection device 111, here an interior camera, which is sensitive in the IR radiation range and is shown here as an example on the headliner of the vehicle 100.

[0096] 19

[0097] The IR illumination patterns are captured by the PMR. The computer unit 52, which is operationally connected to the optical detection device, evaluates the IR illumination patterns for head tracking using appropriate algorithms and can thus perform a 3D reconstruction of the head's position, pose, and / or movement. The information obtained in this way can be used, for example, by a driver assistance system to monitor the position, pose, and / or movement for authentication purposes and / or to monitor the driver's condition, such as fatigue, health, fitness to drive, and / or mood.

[0098] Fig. 9 schematically shows another embodiment of a projection system according to the invention, which comprises a projection device with an imaging unit 200 from Fig. 4, here LBS 22'". The LBS 22'" is arranged together with an optical detection device 111, here an IR camera, within a head-up display 1000 below a windshield 411, as a reflective surface 410. Both the LBS 22'" and the optical detection device 111 form part of the head-up display. A computer unit 52 is operationally coupled to the head-up display 1000 and, via this, to the LBS 22" and the optical detection device 111.

[0099] The head-up display 1000 comprises an imaging unit, an optical unit, and a mirror unit, combined here in the head-up display component HB. A beam of light originates from a projection surface and is reflected by a first mirror, also combined in the head-up display component HB, onto a curved mirror 32, which reflects it towards the reflective surface 410. The reflective surface 410 is represented here as the windshield 411 of the vehicle 100. From there, the beam of light SB2 travels towards the eye of a viewer, here the driver 10 of the vehicle 100.

[0100] The viewer sees a virtual image VB, which is located outside the vehicle, above the hood, in front of the vehicle 100. Through the interaction of the optical unit and the mirror unit, the virtual image 202405042 is created.

[0101] 20

[0102] Image VB is an enlarged representation of the image coming from the projection surface.

[0103] The LBS 22" features an IR laser light source for generating an IR light beam and is designed to generate variable IR illumination patterns (PME) based on this IR light beam. These variable IR illumination patterns (PME), triggered by the computer unit 52, are reflected into the vehicle's interior via the reflective surface 410 (here, the windshield 411) and projected onto a projection surface 210 (here, the driver's head 10). The optical detection device 111 detects the variable IR illumination patterns (PME) on the projection surface 210 via reflection from the windshield 411. The IR illumination patterns (PMR) detected by the optical detection device 111 are then evaluated by the computer unit to perform a 3D reconstruction of the driver's head position, pose, and / or movement.

[0104] In the embodiment schematically depicted in Fig. 9, a possibility for the indirect illumination of a vehicle's interior with variable IR illumination patterns and the indirect detection of a projection surface onto which the IR illumination patterns are projected is thus illustrated. Furthermore, the LBS 22'", which generates the IR illumination patterns, and the optical detection device 111 are components of the HUD shown in Fig. 9. This allows a virtual image to be presented to the viewer of the HUD via the same projection system, here the HUD, and via the same projection path, namely that of the HUD, thus enabling driver monitoring.

Claims

202405042 21 Patent claims 1. Projection system for a vehicle, comprising: - a laser beam scanner (22", 22'"), which includes an IR laser light source 14IR for generating an IR light beam and wherein the laser beam scanner (22", 22'") is configured to generate variable IR illumination patterns (PME) based on the IR light beam, - a projection surface (210, 211) onto which the IR illumination patterns (PME) can be projected, - an optical detection device (111 ) for optically detecting the variable IR illumination patterns on the projection surface (210, 211 ), and - a computing unit (52) configured to control the laser beam scanner (22", 22'") such that it generates the variable IR illumination patterns (PME) and projects them onto the projection surface (210, 211) and wherein the computing unit (52) is configured to evaluate the IR illumination patterns (PMR) detected by the optical detection device (111) on the projection surface (210, 211).

2. Projection system according to claim 1, wherein the projection system has at least one reflective surface (410) which reflects the variable IR illumination patterns in the direction of the projection surface (210, 211).

3. Projection system according to one of claims 1 or 2, wherein the projection system has at least one reflective surface (410) which reflects the variable IR illumination patterns projected onto the projection surface (210, 211) in the direction of the optical detection device (111).

4. Projection system according to one of the preceding claims, wherein the projection system comprises a plurality of laser beam scanners (22", 22'").

5. Projection system according to one of the preceding claims, wherein the laser beam scanner (22", 22'") is arranged below the windshield (411) of the vehicle. 202405042 22 6. Projection system according to one of the preceding claims, wherein the optical detection device (111 ) is arranged below the windshield (411 ) of the vehicle.

7. Projection system according to one of the preceding claims, wherein the laser beam scanner (22", 22'") comprises RGB laser light sources (14R, 14G, 14B) for generating a projection image on a projection surface (210, 211).

8. Featuring a Head-Up Display System (1000): - a laser beam scanner (22", 22'") arranged in the head-up display, which has an IR laser light source (14IR) for generating an IR light beam, wherein the laser beam scanner is designed to generate variable IR illumination patterns (PME) based on the IR light beam, - a reflective surface (410) which reflects the variable IR illumination patterns (PME) into the interior of a vehicle, - an optical detection device (111 ) for optically detecting the variable IR illumination patterns on at least one projection surface (210, 211 ) inside the interior of the vehicle (100), and - a computing unit (52) configured to control the laser beam scanner so that it projects the variable IR illumination patterns (PME) onto the projection surface (210, 211) and wherein the computing unit (52) is configured to evaluate the IR illumination patterns (PMR) detected by the optical detection device (111).

9. Head-Up-Display system according to claim 8, wherein the optical detection device (111 ) is arranged in the head-up display (1000).

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