Means of transport and arrangement for taking an infrared image

Abstract

Arrangement (1) for recording an infrared image inside a means of transport (10) comprising: - an infrared camera (3) arranged on a circuit board (2), - a large number of infrared LEDs (4) arranged statically in the means of transport (10) and - an umbrella (5), wherein the screen (5) is arranged between each LED (4) on the one hand and the infrared camera (3) on the other.

Description

[0001] The present invention relates to a means of locomotion and an arrangement for recording an infrared image within the means of locomotion. In particular, the present invention relates to improved homogeneity and reduced loss of image quality through the use of infrared light diffused within the camera arrangement.

[0002] Modern vehicles are equipped with numerous interior sensors that optically detect the actions, particularly gestures and gaze directions, of occupants. To obtain usable results even in low light conditions, cameras are increasingly being used that, due to their sensitivity in the infrared range, can capture events inside the vehicle in near darkness. To increase the intensity of the infrared range within the vehicle, such camera systems typically incorporate infrared LEDs, which must be tailored to the specific requirements of the camera and its location. Therefore, the LEDs are often integrated as part of a larger camera assembly.

[0003] The detection range (angle of view) of wide-angle cameras is sometimes greater than 140°, while the LEDs emit significant light intensities over a typically much narrower angle. Therefore, adequate illumination of the area captured by the wide-angle camera can only be guaranteed if the camera assembly incorporates a large number of infrared LEDs. However, when multiple LEDs are used, the light cones can overlap, sometimes unfavorably, resulting in overlaps with areas of significantly higher intensity. For optimal detection and interpretation of indoor processes, homogeneous illumination is essential. Using too many LEDs to achieve homogeneous illumination negatively impacts energy consumption and heat output.

[0004] US 2020 / 0029002A1 and DE 102019216328A1 disclose camera arrangements that incorporate active light sources. To prevent stray light from the light sources from entering the camera, screens are provided to interrupt a direct optical path.

[0005] DE 10 2014 215 856 A1 discloses a driver monitoring system in a motor vehicle in which a camera is glued or screwed to the rear of an inner wall of the housing.

[0006] It is therefore an object of the present invention to alleviate or eliminate the aforementioned disadvantages.

[0007] The aforementioned problem is solved according to the invention by an arrangement for recording an infrared image within a means of transport. The arrangement could also be referred to as a "camera arrangement," comprising an infrared camera mounted on a circuit board and a plurality of infrared LEDs statically arranged within the means of transport. In other words, the infrared LEDs are fixedly arranged relative to the circuit board and the infrared camera. In the means of transport, this offers the advantage that vibrations unavoidable during operation cannot cause malfunctions in the arrangement, provided a sufficiently firm connection is ensured. Additionally, a screen is provided, the screen shielding the light from the infrared LEDs from the optics of the infrared camera. In other words, there is no direct or indirect optical axis through components of the arrangement.An optical path between each LED and the camera's optics is interrupted by the screen. In this way, the light from the LEDs can be reflected almost exclusively by reflection off the surroundings of the arrangement towards the infrared camera, and the infrared camera's sensor is not affected by such (scattered) light from the LEDs. This improves the image quality of the arrangement according to the invention.

[0008] The dependent claims describe preferred embodiments of the invention.

[0009] The screen can have an infrared-absorbing surface. This prevents the infrared radiation reflected by the screen from passing through other elements of the arrangement and causing unwanted interference with the optical sensor of the infrared camera. However, the screen can also have an infrared-reflecting surface to improve the light output of the arrangement and to selectively reflect infrared light into its surroundings, resulting in the best possible homogeneity of the light intensity distribution.

[0010] The infrared camera can, for example, have a principal optical axis that is perpendicular to the circuit board of the arrangement. In other words, the camera "looks" in the direction of a surface normal of the circuit board and can therefore be attached to the circuit board in a very space-saving manner using solder joints, clip connections, adhesive connections, or similar methods. This reduces the dimensions of the arrangement according to the invention and increases its stability and fatigue strength.

[0011] The LEDs can, in particular, each have an optical axis that is perpendicular to the circuit board. In other words, the main emission direction of each LED is oriented towards a surface normal of the circuit board, thus enabling a symmetrical intensity distribution of the infrared light with respect to the board. Preferably, however, the respective optical axis of the LEDs can also be inclined on the circuit board. For example, the optical axis can be inclined away from a main optical axis of the infrared camera. In this way, a emission characteristic can be achieved in which the LEDs illuminate, or primarily illuminate, specific sub-areas of the infrared camera's detection range. Thus, optimal homogenization of the intensity distribution can be achieved with as few LEDs and as little heat emission as possible.

[0012] The shield can be attached to the circuit board. In this case, the shield can be understood, for example, as a structure surrounding the infrared camera, within which the infrared camera is located and outside of which the LEDs are positioned. This effectively prevents the shield from being light-tight from the surface of the circuit board. On the side opposite the circuit board, the shield can end at least at the level of the infrared camera lens, or even higher. If the infrared camera has a cover protecting the lens, there is a risk that infrared light from the LEDs will pass between the shield and the cover, be reflected by the cover, and then reach the lens and sensor of the infrared camera as unwanted stray light.To prevent this, the protective cover can be made in contact with the screen, in particular by making contact completely around its perimeter, so that no light can pass between the surface of the cover and the screen. However, reflections from a surface of the cover opposite the camera can also cause the radiation from the infrared LEDs to be reflected into the camera lens. Therefore, it may be necessary to recess the screen into the cover. For this purpose, the cover can, for example, have a groove or other recess corresponding to the contact surface of the screen in order to further reduce the light intensity that could be reflected from the surface of the cover facing away from the camera.Ideally, the protective cover is interrupted at the point where the screen protrudes from the lens, so that the screen completely penetrates the surface of the cover and no surface of the cover can contribute to the reflection of direct infrared radiation. This ensures that the lens only transmits reflected radiation received from the surrounding environment to the camera sensor for image capture.

[0013] The screen can be glued to the surface of the cover or inserted into a groove in the surface of the cover. Depending on the manufacturing process, it is also possible to cast the cover onto the screen, weld it to the screen, or clip / snap it into place. Such a secure connection between the screen and the cover can prevent noise, optical short circuits, and abrasive processes between the cover and screen.

[0014] If a cover is included in the arrangement, the numerous infrared LEDs can be positioned between the cover and the circuit board. In other words, the LEDs are enclosed within a housing, if present, formed by the cover, the circuit board, and the screen. This also prevents foreign objects from coming into contact with the LEDs and causing unforeseen effects on the light intensity distribution.

[0015] To optimize light distribution, the screen can have a hyperbolic surface facing the LEDs, which is typically an outer surface of a rotationally symmetrical reflector. This hyperbolic surface ensures particularly homogeneous illumination of the surrounding area. An inner surface of the screen can, for example, have a cylindrical shape. Specifically, the inner surface is designed to be non-reflective to prevent reflections within the screen and thus avoid reducing image quality. In other words, the infrared camera is positioned within a screen, ensuring that the LEDs surrounding the screen achieve a homogeneous light intensity distribution and are not affected by stray light.

[0016] Preferably, the arrangement comprises a housing within which the circuit board, the cover, the screen, and the infrared camera are arranged. The housing can enclose the aforementioned elements. The aforementioned elements can be connected to the housing directly or indirectly. In this way, a compact and stable assembly is provided, which will not suffer any loss of function, noise, or other adverse developments over the lifetime of a means of transportation.

[0017] According to a second aspect of the present invention, a means of transport is proposed which has an arrangement according to the first aspect of the invention. The means of transport can be configured, for example, as a car, van, motorcycle, truck, aircraft, and / or watercraft. The means of transport has an arrangement which can be, for example, an interior camera in the instrument cluster, dashboard, A-pillar, roof control module, rearview mirror base, or elsewhere, or which can be configured for such arrangement. The means of transport is thus configured to realize the features, combinations of features, and the advantages arising therefrom in such a manner that, to avoid repetition, reference is made to the above descriptions.

[0018] Further details, features and advantages of the invention will become apparent from the following description and the figures. These show: Fig. 1 a schematic side view of an embodiment of a means of locomotion designed according to the invention with an embodiment of an arrangement according to the invention; Fig. 2 a cutaway side view of a first embodiment of an arrangement according to the invention; and Fig. 3 a cutaway side view of a second embodiment of an arrangement according to the invention.

[0019] Fig. Figure 1 shows a car as a means of transport 10, on whose windshield an arrangement 1 comprising a camera 3 and infrared LEDs 4 is mounted. The infrared LEDs 4 each have narrower light cones with boundaries 41, 42, 43, 44. Only in the direction of a principal optical axis of the infrared camera 3, in which the face of a user is also located, do the edge regions of the light cones overlap. The principal optical axis 6 is also perpendicular to a circuit board (not shown) on which the camera 3 is mounted. A detection range of the infrared camera 3 is defined by the range boundaries 31, 32. These run essentially parallel to the boundaries 41, 44 of the light cones.

[0020] Fig. Figure 2 shows a sectional side view through an arrangement 1 according to the invention. An infrared camera 3 is provided with a lens 9, a body 3b, and a pixel sensor 3a and is arranged on a circuit board 2 such that its principal axis 6 is perpendicular to the surface of the circuit board 2. A cover 11 protects the camera 3 against environmental influences. Infrared LEDs 4 are arranged to the right and left of the camera 3, their principal optical axes 7a, 7b being inclined away from the camera 3. The infrared LEDs 4 each have lenses 9 which influence the emission characteristics of the infrared light. In particular, the lenses 9 focus the emitted light onto a solid angle that is narrower than the detection range of the camera 3. The infrared LEDs each have circuit boards 2a, 2b inclined according to their principal axes 7a, 7b, which are connected to the main circuit board 2 via bond wires 12.A screen 5 is provided between the LEDs 4 and the camera 3, the ends of which face the cover 11 and are recessed into the cover 11. This prevents radiation emitted by the LEDs 4 from being reflected towards the lens 9 from any surface of the cover 11 facing the camera 3. The screen 5 can be designed as a hollow cylinder and can be attached either exclusively to the cover 11 or alternatively or additionally to the circuit board 2.

[0021] Fig. Figure 3 shows a second embodiment of an arrangement 1 according to the invention, in which the screen 5 has a hollow cylindrical inner wall which is designed to absorb light, while its outer surface is hyperbolic and thus light-reflecting. The screen 5 is attached to both the circuit board 2 and the cover 11. The hyperbolic outer surface allows the intensity distribution of the light emitted by the infrared LEDs 4 to be favorably influenced in such a way that the infrared LEDs 4 can have a main emission axis 7a, 7b which is perpendicular to a surface of the circuit board 2. This enables significantly more cost-effective manufacturing and a reduction in the number of parts. In particular, the wiring of the LEDs to the circuit board 2 can also be carried out essentially automatically, so that bond wires (see Figure 3) are no longer required. Fig.Reference numeral 2 (reference numeral 12) can be omitted. Additionally, a housing 13 is indicated on the left side, which has a groove for receiving the cover 11 and a groove for receiving the circuit board 2. The housing 13 can, in particular, be designed in multiple parts and ensure a predefined positioning of the cover 11 and the circuit board 2. The screen 5 itself can be made of plastic, metal, glass, or another material. In particular, a surface coating to influence the light absorption or reflection behavior can be subsequently applied as a lacquer or vapor-deposited surface, etc. On its side facing the cover 11, the screen 5 can extend at least approximately through the cover 11, so that the cover 11 can be designed in multiple parts (e.g., an inner disc and an outer ring). Reference symbol list: 1. Arrangement 2 circuit boards 2a, 2b LED board 3 cameras 3a Image sensor 3b Corpus 4 LED 5 umbrella 6. Main optical axis 7a, 7b principal optical axis 9 lens 10 means of transport 11 Cover 12 Bond wire 13 cases 31, 32, 41, 42, 43, 44 borders

Claims

[1] Arrangement (1) for recording an infrared image inside a means of transport (10) comprising: - an infrared camera (3) arranged on a circuit board (2), - a large number of infrared LEDs (4) arranged statically in the means of transport (10) and - an umbrella (5), wherein the screen (5) is arranged between each LED (4) on the one hand and the infrared camera (3) on the other. [2] Arrangement (1) according to claim 1, wherein - the infrared camera (3) has a principal optical axis (6) which is perpendicular to the circuit board (2) and / or - the LEDs (4) each have an optical axis (7a, 7b) which is perpendicular or inclined to the circuit board (2). [3] Arrangement (1) according to claim 1 or 2 further comprising - a base which holds at least one of the LEDs (4) above the circuit board (2), wherein the base is in particular designed at least partially in a frustoconical shape or as a circuit board. [4] Arrangement (1) according to one of the preceding claims, wherein the screen (5) ends at the level of a lens (9) of the infrared camera (3) or above the lens (9) and in particular terminates with a cover (11) protecting the lens (9). [5] Arrangement (1) according to claim 4, wherein the screen (5) is embedded in a surface of the cover (11). [6] Arrangement (1) according to claim 4 or 5, wherein the LEDs (4) are arranged between the cover (11) and the circuit board (2). [7] Arrangement (1) according to one of the preceding claims, wherein the screen (5) has a hyperbolic surface facing the LEDs (4), which is in particular an outer surface of a body, in particular having a cylindrical inner surface. [8] Arrangement (1) according to one of the preceding claims - insofar as it refers back to one of the preceding claims 4, 5 and 6 - further comprising a housing (13) enclosing the infrared camera (3), the circuit board (2), the cover (11) and the screen (5). [9] Means of transport comprising an arrangement according to any of the preceding claims.

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