Motor vehicle

Abstract

Motor vehicle (1), comprising at least one rearview mirror (6) provided for use by the driver, having a reflective mirror surface formed by a mirror material (9), in particular an interior mirror (8) and / or an exterior mirror (7), and at least one interior window (2) comprising a window material (13), in particular glass, in particular a windscreen (3) and / or a rear window (4) and / or at least one side window (5), wherein the at least one rearview mirror (6) comprises a filter means (11) reflecting light in at least one wavelength range in a different direction than light outside the wavelength range, wherein at least one of the at least one wavelength range is a wavelength range used by lidar sensors.

Description

[0001] The invention relates to a motor vehicle, comprising at least one rearview mirror provided for use by the driver with a reflective mirror surface formed by a mirror material, in particular an interior mirror and / or an exterior mirror, and at least one interior window, in particular a windscreen and / or a rear window and / or at least one side window.

[0002] For example, due to the increase in automated functions in motor vehicles, particularly for at least partially automatic vehicle guidance, the requirements and needs regarding environmental sensors in motor vehicles are increasing. One environmental sensor concept frequently proposed for modern motor vehicles is Lidar. Lidar uses light, particularly in the near-infrared range, for example, in the wavelength range from 900 nm to 1550 nm, to measure objects in the vehicle's surroundings. By emitting light pulses and receiving the reflected light pulses, distance measurement is also possible. The detection range of Lidar sensors in motor vehicles correlates directly with the power used for the emitted light; today, for example, ranges of 300 m or more are targeted.However, there are limitations to the performance of lidar sensors regarding human safety, particularly eye safety. At extremely high power levels, electromagnetic waves in the wavelength range from 900 nm to 1550 nm can cause damage. Therefore, specific regulations are currently in place so that, for example, lidar sensors are assigned specific protection classes and approved. Control systems for lidar sensors use control mechanisms to continuously monitor the output power.

[0003] Nevertheless, there is a desire to be able to use higher power levels, and on the other hand, despite the fact that lidar radiation generally provides eye safety, comfort limitations can occur, for example, despite the use of light outside the visible range, perception effects can occur.

[0004] Furthermore, laser speed measuring devices for motor vehicles have already been proposed in the prior art, for example, to conduct traffic checks. Such laser speed measuring devices can be designed as laser guns, for example. In these cases, laser light in the non-visible infrared or near-infrared range is often used, which can lead to similar problems to those associated with lidar sensors, in particular a limitation in performance and the risk of reduced comfort for drivers.

[0005] US 2013 / 0 148 063 A1 relates to a reflective device in which the reflectivity can be adjusted automatically or manually. In particular, a mirror arrangement with a dimming function is proposed.

[0006] US 2017 / 0 242 272 A1 relates to a system and method for protecting eyes against laser light. It proposes a goggle-like eye protection system with two lenses and a lens carrier, with the first lens filtering light of one or more first wavelengths, and the second lens filtering light of one or more second wavelengths.

[0007] WO 2013 / 034 236 A1 relates to a vehicle window, in particular for a motor vehicle, wherein the vehicle window has a switchable functional layer for making the vehicle window opaque. In particular, a so-called suspended particle device (SPD) is used. However, the problem arises that an SPD functional layer has its own color, which is why, in order to achieve the most neutral color possible, it is proposed to use at least one reflection and / or absorption layer in addition to the switchable functional layer, which is designed to reflect and / or absorb wavelengths of light for which the functional layer is transparent in a state of reduced light transmittance, resulting in a neutral, in particular gray, color.

[0008] DE 10 2017 109 550 A1 relates to a side mirror for a motor vehicle with an optical detection device for detecting a blind spot area for a driver, in which a better detection of the blind spot area should be possible, which is why the optical detection device in the side mirror should have at least one lidar sensor. The side mirror can have a housing, and the lidar sensor can be arranged in an interior of the housing, wherein the light beams of the lidar sensor radiate through a housing part. The housing part can be semi-transparent in order to reflect a first part of the light beams from the environment and transmit a second part of the light beams into the interior of the housing. In this way, the housing part can reflect in the wavelength range of visible light and yet easily allow the lidar light that was reflected from the environment to re-enter the housing.

[0009] US 2018 / 0 284 268 A1 discloses a lidar system in which, in order to clear the line of sight of a window of the lidar system, the window is coupled to ultrasonic transducers which are intended to shake off dirt by vibration.

[0010] US 6,353,392 B1 relates to a vehicle rain sensor system for detecting precipitation on an outer surface of a windshield. The rain sensor system includes an illumination sensor that is decoupled from the windshield. A controller includes an edge detection function that uses the light values ​​detected by the sensor to detect the edges of precipitation drops on the windshield and activates the vehicle's windshield wipers when the sum of the light values ​​exceeds a predetermined threshold. The rain sensor system can also include a polarization filter and an illumination source, so that the rain sensor system not only prevents false rain signals when there is merely fog on an inner surface of the windshield, but also actually detects fog particles on an inner surface of the windshield.To prevent a heat protection mechanism of the disc from blocking light from the illumination source, a light wave range at the edge of the visible spectrum is chosen.

[0011] The invention is based on the object of specifying a design of a motor vehicle which increases the eye comfort for passengers and in particular also provides the basis for higher performance in lidar sensors and / or laser measuring devices.

[0012] To achieve this object, the features of claim 1 are provided according to the invention in a motor vehicle of the type mentioned above. Optionally, the at least one interior pane can additionally comprise a filter medium that absorbs and / or reflects light in at least one wavelength range.

[0013] The filter medium can in particular comprise an absorption filter medium and / or a dichroic filter medium and / or an interference filter medium. Absorption filters are designed to absorb light in the wavelength range and convert it into internal energy, for example, heat. Another variant is photochromic materials, which undergo a reversible transformation through the absorption of electromagnetic radiation. A dichroic filter, on the other hand, reflects unwanted wavelengths and allows the desired part of the spectrum to pass through. A dichroic filter can, for example, be created by a sequence of one or more thin layers of different materials with different refractive indices. Finally, interference filter media are also conceivable, which utilize the effect of interference to filter light depending on the frequency.

[0014] The filter medium may comprise a filter material incorporated into the mirror material and / or a disc material, which may in particular also be incorporated as a layer. Furthermore, it is conceivable for the filter medium to comprise a filter layer, in particular a filter film, arranged outside the mirror material.

[0015] According to the invention, it is therefore proposed to provide at least one rearview mirror, preferably all rearview mirrors, i.e., exterior and interior mirrors, and optionally additionally an interior window pane, with a filter medium, in particular a filter material and / or a filter layer, that reflects and optionally absorbs electromagnetic radiation in a specific wavelength range. In this way, a protective and comfort-enhancing function of the rearview mirrors and optionally additional interior windows is provided, particularly with regard to potentially disruptive light, especially light that is not in the visible range.

[0016] The invention provides that at least one of the at least one wavelength range is a wavelength range used by lidar sensors. In particular, it can be provided that, particularly for the at least one rearview mirror, at least one of the at least one wavelength range lies in the near-infrared range and / or the infrared range. The wavelength range can, for example, lie within the entire range from 900 nm to 1550 nm or even encompass this entire range. For example, current pulse lidar sensors use wavelengths of 905 nm, while current FCMW lidar sensors, i.e., continuous-wave lidar sensors, operate in the wavelength range from 1350 nm to 1550 nm.Both such light-absorbing rearview mirrors and such light-absorbing or light-reflecting interior windows contribute to increased comfort and driver protection and can potentially offer new design freedom due to the reduced penetration of the lidar radiation used to the occupants of the vehicle.

[0017] Furthermore, an expedient development of the present invention can provide that, particularly for a reflective filter medium of the interior window pane, the at least one wavelength range comprises at least one laser wavelength. This can particularly relate to laser wavelengths of a laser speed measuring device, for example, a laser gun. Since such laser speed measuring devices frequently also operate in the near-infrared and / or infrared range, it is certainly conceivable to define a wavelength range and tune the filter medium to this wavelength range, which includes both wavelengths used by lidar sensors and laser wavelengths used by laser speed measuring devices.

[0018] In a specific embodiment of the present invention, it can be provided that, in the case of a windshield of a motor vehicle as an interior window, the laser wavelength is a laser wavelength used by a laser speed measuring device. In particular, all interior windows can also be provided with a filter medium, for example filter material, that absorbs or reflects the laser wavelength in order to significantly reduce the intensity of the laser beams. In particular, in a windshield, it is expedient to minimize the transparency or penetration of the laser beams, since this is the main direction from which measurements are taken with a laser speed measuring device. In a specific embodiment, it can be provided, for example, to use reflective filter material on the outer surface of the windshield.

[0019] It should be pointed out again that absorbent filter media are preferred for the rear-view mirrors, since reflection, particularly with regard to other occupants of the motor vehicle, should be minimized as much as possible. The use of materials that reflect in other directions is only considered expedient in the exterior mirrors. In particular, in a specific embodiment of the present invention, it can be provided that in at least one of the at least one rear-view mirrors, in particular at least one exterior mirror, a material that is retroreflective in the wavelength range is used as the filter material of the filter medium. In this embodiment, laser beams and / or lidar signals, for example, are simply reflected back in their direction of emission, while other light components, in particular those in the visible range, are further reflected as desired to provide information towards the occupant, in particular the driver.Such a retroreflective filter material can also be made up of nano- and / or microparticles that have a frequency-selective effect.

[0020] Further advantages and details of the present invention will become apparent from the exemplary embodiments described below and from the drawings. In the drawings: Fig. 1 a schematic diagram of a motor vehicle according to the invention, Fig. 2 a schematic view of an exterior mirror, and Fig. 3 a schematic section through a windscreen.

[0021] Fig. 1 shows a schematic diagram of a motor vehicle 1 according to the invention. In the present case, this has a windshield 3, a rear window 4, and four side windows 5 as interior windows 2. Furthermore, the motor vehicle 1 comprises two exterior mirrors 7 and an interior mirror 8 as rearview mirrors 6, each comprising a mirror material 9. In the present exemplary embodiment, all interior windows 2 and all rearview mirrors 6 are provided with filter means 10, 11 related to a specific wavelength range, which are each indicated only schematically; the filter means 10 of the interior windows 2, for example, are shown as hatching.

[0022] The filter media 10, 11 in this case all refer to the wavelength range from 900 nm to 1550 nm, i.e., the near-infrared range. This range includes the wavelength range used by lidar sensors as well as the laser wavelengths used by laser speed measuring devices.

[0023] The filter means 10, 11 can generally comprise absorption filter means, dichroic filter means and / or interference filter means. For the exterior mirrors 7, as shown in Fig. 2, retroreflective materials 12 are also suitable, which can be embedded in the mirror material 9, but can also be provided as an outer layer. The retroreflective material 12 reflects electromagnetic waves of the wavelength range back in the direction from which they arrived, while other light is reflected by the mirror material 9 as usual.

[0024] As already mentioned, a filter material can be integrated into the mirror material 9 for the rear-view mirrors as a whole; however, layers applied externally are also possible, and these embodiments also apply to the interior windows. Fig.3 shows in this regard a schematic cross-sectional view of an interior window 2, here the windscreen 3, which, in addition to the window material 13, comprises a filter layer 14 applied externally to the window material 13 as a filter means 10, which in the present case has a reflective effect and in this way significantly reduces electromagnetic radiation of the wavelength range penetrating into the interior of the motor vehicle 1.

[0025] Such a design of the front screen 3 is particularly useful with regard to laser speed measuring devices, for example laser guns, since such measurements are usually carried out from the front.

[0026] Nevertheless, it should be noted that, within the scope of the present invention, filter means 10, 11 can also be used which relate to a wavelength range which includes wavelengths used for laser headlights of other road users in order to achieve an increase in comfort in this regard.

Claims

[1] Motor vehicle (1), comprising at least one rear-view mirror (6) provided for use by the driver with a reflective mirror surface formed by a mirror material (9), in particular an interior mirror (8) and / or an exterior mirror (7), and at least one interior window (2) comprising a window material (13), in particular glass, in particular a windscreen (3) and / or a rear window (4) and / or at least one side window (5), wherein the at least one rear-view mirror (6) comprises filter means (11) reflecting light in at least one wavelength range in a different direction than light outside the wavelength range, wherein at least one of the at least one wavelength range is a wavelength range used by lidar sensors. [2] Motor vehicle (1) according to claim 1, characterized bythat the at least one interior pane (2) additionally comprises filter means (10) which absorb and / or reflect light in at least one wavelength range. [3] Motor vehicle (1) according to claim 1 or 2, characterized by that the filter means (10, 11) comprises an absorption filter means and / or a dichroic filter means and / or an interference filter means. [4] Motor vehicle (1) according to one of the preceding claims, characterized by that the filter means (10, 11) comprises a filter material introduced into the mirror material (9) and / or the pane material (13), in particular as a layer. [5] Motor vehicle (1) according to one of the preceding claims, characterized by that the filter means (10, 11) comprises a filter layer (14), in particular a filter film, arranged outside the mirror material (9) and / or the pane material (13). [6] Motor vehicle (1) according to one of the preceding claims, characterized bythat at least one of the at least one wavelength range lies in the near-infrared range and / or infrared range. [7] Motor vehicle (1) according to one of the preceding claims, characterized by that the at least one wavelength range comprises at least one laser wavelength. [8] Motor vehicle (1) according to claim 7, characterized by in that in a windscreen (3) of the motor vehicle (1) which has the filter means (10) of the interior window (2), the laser wavelength is a laser wavelength used by a laser speed measuring device. [9] Motor vehicle (1) according to one of the preceding claims, characterized by that in at least one of the at least one rearview mirror (6), in particular the exterior mirror (7), a material (12) which is retroreflective in the wavelength range is used as the filter material of the filter means (11).

Images