Arrangement for driver assistance system

Abstract

The invention relates to an arrangement (1) of a driver assistance system (100) for a vehicle (2) for monitoring at least one vehicle user (15), comprising a radiation source (3) for emitting near-infrared radiation, a radiation receiver (4) for receiving near-infrared radiation, a thermal imaging camera (5) and a windshield (6), the invention relates to a windscreen (6) comprising an outer pane (7) having an outer side surface (I) and an inner side surface (II) and an inner pane (8) having an outer side surface (III) and an inner side surface (IV), which are connected to one another via a thermoplastic intermediate layer (9), a functional layer (10) reflecting near-infrared radiation being arranged on the inner side surface (II) of the outer pane (7) or on the outer side surface (III) of the inner pane (8), and a functional layer (11) that reflects heat radiation is arranged on the inside surface (IV) of the inner pane (8).

Description

[0001] The invention relates to an arrangement having a windshield, a radiation source for emitting near-infrared radiation, a radiation receiver for receiving near-infrared radiation and a thermal imaging camera for a driver assistance system for a vehicle, the driver assistance system being capable of monitoring at least one vehicle user, in particular the driver. The invention further relates to the use of the arrangement in a driver assistance system, to a driver assistance system for a vehicle comprising such an arrangement, and to a method for monitoring at least one vehicle user, in particular the driver of a vehicle.

[0002] Modern vehicles are often equipped with electronic driver assistance systems that support the driver in guiding the vehicle, for example by automatically applying the brakes when there is a risk of collision or automatically keeping the lane when the vehicle leaves its lane. Such driver assistance systems have proven to be very successful in practice, especially when they have driver monitoring functions, such as early detection of driver fatigue and excessive distraction from safe vehicle operation, such as by operating a mobile phone.

[0003] To this end, it is known to scan the driver's face, in particular his or her eyes, using near infrared radiation, which is invisible to the naked eye and thus does not disturb the driver and other vehicle occupants. From this, algorithms can be used to capture the driver's gaze direction and gaze duration, which can indicate fatigue, for example if the gaze duration in a particular direction is unusually long (staring). On the other hand, looking away from the direction of travel too frequently may indicate distraction. Facial expressions can also be recognized, which can also indicate the driver's state.

[0004] EP 1 333 410 A2 discloses a device for eye tracking of a vehicle driver.

[0005] DE 10 2014 115 958 A1 discloses a system for monitoring a vehicle driver, comprising an infrared flash for radiating infrared light onto the driver, an infrared camera for recording images of the light beam (including reflections), and reflective infrared sheeting incorporated into the vehicle windshield.

[0006] US 2015 / 0294169 A1, US 2020 / 0023739 A1, and US 2020 / 0143184 A1 also disclose driver assistance systems.

[0007] US 2020 / 143560 A1 discloses a driver assistance system for a vehicle, comprising a radiation source that emits invisible light that illuminates at least a portion of a vehicle driver. A mirror selective reflector is arranged at a windshield of the vehicle. The reflector reflects at least a portion of the invisible light (such as infrared (IR) and / or near infrared (NIR) radiation) incident at the reflector, and allows visible light to pass through the reflector and the windshield so as to direct the emitted invisible light to the driver while allowing the driver to observe through the reflector at the windshield. The camera is arranged in the dashboard of the vehicle and has a field of view away from the driver that includes or surrounds the reflector.

[0008] US 10 322 728 B1 discloses a system for determining the load of a vehicle driver, which includes multiple sensors, including an image sensor inside the vehicle, an audio sensor inside the vehicle, a vehicle data sensor, and a GPS data sensor. The system further includes one or more processors configured to receive inputs from the multiple sensors and process the received inputs to provide a driver thermal change assessment, a driver facial expression assessment, a driver gesture assessment, and an on-board fault diagnosis and GPS assessment. The one or more processors are further configured to store the assessment in a memory, use the stored assessment to generate a variance score for each assessment, execute a machine learning algorithm to classify the driver behavior as normal driving or impaired driving based on the variance score, and generate an alarm indicating impaired driver behavior based on the classification.

[0009] WO 2022 / 157021A1 discloses a projection arrangement for a head-up display (HUD), comprising at least a windshield, the windshield comprising an outer glass pane and an inner glass pane connected to each other via a thermoplastic interlayer, having a HUD region and a projector directed toward the HUD region and emitting p-polarized radiation, wherein a reflective coating is arranged on the surface of the outer glass pane facing the interlayer or on the surface of the inner glass pane facing the interlayer or inside the interlayer, the reflective coating being suitable for reflecting p-polarized radiation and having only one silver-based conductive layer, and a thermal radiation reflective coating is arranged on the surface of the inner glass pane facing away from the interlayer, the thermal radiation reflective coating comprising a conductive layer based on a transparent conductive oxide. The reflective coating has IR-reflecting properties due to the conductive silver layer, so that it acts as a solar control coating for reducing heating of the vehicle interior by reflecting the infrared part of the solar radiation (in particular in the near infrared range, for example in the range of 800 nm to 1500 nm).

[0010] Modern driver assistance systems operate at wavelengths in the range of approximately 1 μm (micrometer) to 2 μm, in particular near infrared radiation at a wavelength of 940 nm or at a wavelength of 1400 nm or at a wavelength of 1550 nm.

[0011] It may be desirable to determine other information in addition to near infrared based monitoring functions, such as information regarding the vital signs and / or comfort status of the driver and / or other vehicle occupants in the vehicle.

[0012] The object of the present invention is to provide an improved arrangement for a driver assistance system with a monitoring function for at least one vehicle occupant, which allows simple and reliable acquisition of information about the at least one vehicle occupant.

[0013] According to the proposal of the invention, these and other objects are achieved by an arrangement, a driver assistance system and a method according to the independent patent claims. Preferred embodiments follow from the dependent claims.

[0014] The invention relates to an arrangement of a driver assistance system for a vehicle, in particular a motor vehicle, which has the function of monitoring at least one vehicle occupant of the vehicle based on near infrared radiation and thermal radiation.

[0015] The arrangement according to the invention of a vehicle driver assistance system for monitoring at least one vehicle occupant comprises a radiation source for emitting near-infrared radiation, a radiation receiver for receiving near-infrared radiation and a thermal imaging camera for receiving thermal radiation. The arrangement further comprises a windshield comprising an outer glass pane and an inner glass pane connected to each other by a thermoplastic interlayer.

[0016] The windshield is provided to separate the interior environment from the exterior environment in the window of the vehicle. In the sense of the present invention, the term "inner glass pane" refers to the glass pane of the windshield facing the interior of the vehicle. The outer glass pane refers to the glass pane facing the exterior environment.

[0017] The outer glass pane and the inner glass pane each have an outer side surface and an inner side surface and a peripheral side edge extending therebetween. In the context of the present invention, the outer surface refers to the main surface that is arranged to face the external environment when installed. In the context of the present invention, the inner side surface refers to the main surface that is intended to face the internal space when installed. The inner side surface of the outer glass pane and the outer surface of the inner glass pane face each other and are connected to each other by a thermoplastic interlayer.

[0018] The outside surface of the outer glass sheet is called face I, and the inside surface of the outer glass sheet is called face II. The outside surface of the inner glass sheet is called face III. The inside surface of the inner glass sheet is called face IV.

[0019] According to the invention, the windshield has a functional layer that reflects near infrared radiation. The functional layer that reflects near infrared radiation is suitable for reflecting near infrared radiation. The functional layer that reflects near infrared radiation is arranged on the inner surface of the outer glass sheet or on the outer surface of the inner glass sheet.

[0020] Furthermore, the windshield has a functional layer that reflects thermal radiation. The functional layer that reflects thermal radiation is suitable for reflecting thermal radiation. The functional layer that reflects thermal radiation is arranged on the inner surface of the inner glass pane; in particular, the functional layer that reflects thermal radiation is designed as a coating on the inner surface of the inner glass pane.

[0021] The radiation source is arranged so that the near infrared radiation emitted from the radiation source is directed to the functional layer reflecting the near infrared radiation, and can be reflected from the functional layer reflecting the near infrared radiation to the face of the vehicle user. Thus, the near infrared radiation emitted by the radiation source directly irradiates the functional layer reflecting the near infrared radiation without prior reflection and is reflected by it. For ease of reference, the near infrared radiation reflected from the functional layer reflecting the near infrared radiation is designated as the first reflected radiation. Thus, the first reflected radiation irradiates the face of the vehicle user and can be reflected back to the functional layer reflecting the near infrared radiation by the face of the vehicle user. For ease of reference, the near infrared radiation reflected from the face of the vehicle user is designated as the second reflected radiation. The second reflected radiation that strikes the functional layer reflecting the near infrared radiation is subsequently reflected by the functional layer reflecting the near infrared radiation. For ease of reference, the near infrared radiation reflected from the functional layer reflecting the near infrared radiation is designated as the third reflected radiation. Thus, the radiation receiver is arranged so that the third reflected radiation reflected from the functional layer reflecting the near infrared radiation can be reflected to the radiation receiver and received by the radiation receiver.

[0022] The thermal imaging camera and the functional layer reflecting thermal radiation are aligned so that thermal radiation emitted from the face of the vehicle user illuminates the functional layer reflecting thermal radiation and is reflected by the functional layer reflecting thermal radiation in the direction of the thermal imaging camera and can be received by the thermal imaging camera.

[0023] Thus, in the arrangement according to the present invention, a radiation source, a functional layer reflecting near-infrared radiation, a functional layer reflecting thermal radiation, a thermal imaging camera and a radiation receiver are arranged so that the near-infrared radiation emitted from the radiation source can be reflected from the functional layer reflecting near-infrared radiation to the face of the vehicle user as first reflected radiation, the first reflected radiation can be reflected from the face of the vehicle user to the functional layer reflecting near-infrared radiation as second reflected radiation, and the second reflected radiation reflected from the functional layer reflecting near-infrared radiation as third reflected radiation can be reflected to and received by the radiation receiver, and it is also arranged so that the thermal radiation emitted from the face of the vehicle user can be reflected from the functional layer reflecting thermal radiation as reflected thermal radiation to the thermal imaging camera and received by the thermal imaging camera.

[0024] In the sense of the present invention, near infrared radiation is understood to mean radiation having a wavelength in the range from 800 nm to 2500 nm, preferably from 800 nm to 1600 nm.

[0025] Thermal radiation in the sense of the present invention is understood to mean radiation having a wavelength in the range from 5 μm (micrometers) to 14 μm, preferably from 7 μm to 14 μm, particularly preferably from 8 μm to 14 μm.

[0026] The glass pane has a high absorptivity for thermal radiation having a wavelength in the range of 5 μm to 14 μm. Without a functional layer applied to the inner side surface of the inner glass pane which reflects thermal radiation, almost all thermal radiation emitted by a vehicle user in the direction of the windshield would thereby be absorbed by the inner glass pane and receiving the reflected thermal radiation by means of a thermal imaging camera to determine information about the vehicle user would not be possible.

[0027] Preferably, the near infrared radiation emitted by the radiation source is reflected only in the first sub-region of the windshield. Likewise preferably, the third reflected radiation is reflected only in the second sub-region of the windshield.

[0028] Preferably, the thermal radiation emitted by the face of the vehicle user is reflected only in the third sub-region of the windshield.

[0029] The first sub-region, the second sub-region, and the third sub-region may be separate, partially overlapping, or completely overlapping (ie, identical).

[0030] Preferably, the first sub-region, the second sub-region and the third sub-region completely overlap; ie they are identical.

[0031] In a preferred embodiment, the functional layer reflecting near infrared radiation is arranged on the inner surface of the outer glass pane. In this embodiment, the functional layer reflecting near infrared radiation is designed in particular as a coating of the inner surface of the outer glass pane.

[0032] In an alternative preferred embodiment, the functional layer reflecting near infrared radiation is arranged on the outer side surface of the inner glass pane. In this embodiment, the functional layer reflecting near infrared radiation is designed in particular as a coating on the outer side surface of the inner glass pane.

[0033] Particularly preferred is an embodiment of the arrangement according to the invention in which the functional layer reflecting near-infrared radiation is arranged on the outer side surface of the inner glass pane. This embodiment offers the advantage over the embodiment in which the functional layer reflecting near-infrared radiation is arranged on the inner side surface of the outer glass pane in that the near-infrared radiation emitted by the radiation source and the second reflected radiation do not have to pass through the thermoplastic interlayer before they impinge on the interlayer reflecting near-infrared radiation, and the first reflected radiation and the third reflected radiation likewise do not have to pass through the thermoplastic interlayer before they impinge on the face of the vehicle user and the radiation receiver, respectively.

[0034] The functional layer reflecting near infrared radiation preferably extends over a large area of ​​the windshield. The term "large area" means that the functional layer reflecting near infrared radiation extends over at least 50%, at least 60%, at least 70%, at least 75% or preferably at least 90% of the windshield. However, the functional layer reflecting near infrared radiation can also extend only over a sub-area of ​​the windshield.

[0035] Particularly preferably, the functional layer reflecting near infrared radiation extends substantially over the entire area of ​​the windshield, i.e. over the entire area or over the entire area except for a peripheral edge area and a local area which is optionally intended to serve as a communication, sensor or camera window to ensure the transmission of electromagnetic radiation through the windshield. The peripheral edge area has, for example, a width of at most 20 cm. It prevents the functional layer reflecting near infrared radiation from direct contact with the surrounding atmosphere, thereby protecting the functional layer reflecting near infrared radiation inside the windshield from corrosion and damage.

[0036] The functional layer reflecting thermal radiation also preferably extends over a large area of ​​the windshield. The term "large area" means that the functional layer reflecting thermal radiation extends over at least 50%, at least 60%, at least 70%, at least 75% or preferably at least 90% of the windshield. However, the functional layer reflecting thermal radiation can also extend only over a sub-area of ​​the windshield.

[0037] Particularly preferably, the functional layer reflecting thermal radiation extends substantially over the entire area of ​​the windshield, i.e. over the entire area or over the entire area with the exception of a peripheral edge region and a local region which is optionally intended to serve as a communication, sensor or camera window to ensure the transmission of electromagnetic radiation through the windshield. The peripheral edge region has, for example, a width of at most 20 cm.

[0038] Preferably, the functional layer reflecting near-infrared radiation comprises a layer system having at least one metal layer, in particular at least one metallic silver layer, embedded between dielectric oxide or nitride layers.

[0039] In a particularly preferred embodiment of the arrangement according to the invention, the functional layer reflecting near-infrared radiation comprises a layer system having three silver layers embedded between dielectric oxide or nitride layers. The functional layer reflecting near-infrared radiation can be constructed, for example, as one of the layer systems based on three silver layers described in WO 2013 / 104438 A1 and WO 2013 / 104439 A1.

[0040] In a preferred embodiment, the functional layer reflecting near-infrared radiation has at least three functional layers stacked on top of each other, and each functional layer comprises at least

[0041] - a layer of optically high refractive material having a refractive index greater than or equal to 2.1,

[0042] - a smoothing layer containing at least one amorphous oxide above the layer of optically high refractive index material,

[0043] - a first adaptation layer above the smoothing layer,

[0044] - a conductive layer above the first adaptation layer, and

[0045] A second adaptation layer above the conductive layers, wherein the total layer thickness of all conductive layers is 25 nm to 75 nm and the functional layer reflecting near-infrared radiation has a sheet resistance of less than 1.3 Ohm / square, preferably less than 1.0 Ohm / square.

[0046] In this preferred embodiment, the optically high-refractive material layer preferably has a refractive index n of 2.1 to 2.5, particularly preferably 2.1 to 2.3.

[0047] In this preferred embodiment, the optically high refractive material layer preferably contains at least one silicon / metal mixed nitride, particularly preferably a silicon / zirconium mixed nitride. This is particularly advantageous for the sheet resistance of the functional layer reflecting near-infrared radiation. The mixed silicon / zirconium nitride preferably has a dopant. The optically high refractive material layer may contain, for example, aluminum-doped silicon / zirconium mixed nitride (SiZrN x :Al).

[0048] In this preferred embodiment, the silicon / zirconium mixed nitride is preferably deposited by magnetic field-assisted sputtering with a target containing 40% to 70% by weight of silicon, 30% to 60% by weight of zirconium and 0% to 10% by weight of aluminum and production-related admixtures. The target particularly preferably contains 45% to 60% by weight of silicon, 35% to 55% by weight of zirconium and 3% to 8% by weight of aluminum and production-related admixtures. The deposition of the silicon / zirconium mixed nitride is preferably carried out in a cathode sputtering process with the addition of nitrogen as reaction gas.

[0049] However, the optical high refractive material layer may also contain at least, for example, silicon / aluminum mixed nitride, silicon / hafnium mixed nitride, or silicon / titanium mixed nitride. The optical high refractive material layer may alternatively contain, for example, Nb2O5, Bi2O3, TiO2, Zr3N4 and / or AlN.

[0050] In this preferred embodiment, the layer thickness of each optically high refractive material layer arranged between two conductive layers is preferably 35 nm to 70 nm, particularly preferably 45 nm to 60 nm. The thickness of the lowermost layer of the optically high refractive material is preferably 10 nm to 40 nm.

[0051] In an advantageous design of this preferred embodiment, the cover layer is arranged above the uppermost functional layer. The cover layer may contain, for example, silicon nitride and / or tin oxide.

[0052] In this preferred embodiment, the cover layer preferably contains at least one optically high refractive material having a refractive index greater than or equal to 2.1. The cover layer particularly preferably contains at least one silicon / metal mixed nitride, in particular a silicon / zirconium mixed nitride, such as an aluminum-doped silicon / zirconium mixed nitride. However, the cover layer may also contain other silicon / metal mixed nitrides, such as silicon / aluminum mixed nitrides, silicon / hafnium mixed nitrides or silicon / titanium mixed nitrides. Alternatively, the cover layer may also contain, for example, Nb2O5, Bi2O3, TiO2, Zr3N4 and / or AlN.

[0053] The thickness of the cover layer of this preferred embodiment is preferably 10 nm to 40 nm. This achieves particularly good results.

[0054] In this preferred embodiment, the smoothing layer contains at least one amorphous oxide. The oxide may be amorphous or partially amorphous (and therefore partially crystalline), but not completely crystalline. The amorphous smoothing layer has a low roughness and thus forms a favorable smooth surface for the layer to be applied on the smoothing layer. The amorphous smoothing layer also achieves an improved surface structure of the layer deposited directly on the smoothing layer (which is preferably the first adaptation layer). The smoothing layer may contain, for example, at least one oxide of one or more of the elements tin, silicon, titanium, zirconium, hafnium, zinc, gallium and indium.

[0055] In this preferred embodiment, the smoothing layer preferably contains an amorphous mixed oxide. The smoothing layer most preferably contains a tin / zinc mixed oxide. The mixed oxide may have a dopant. The smoothing layer may contain, for example, an antimony-doped tin / zinc mixed oxide (SnZnO x:Sb). The mixed oxide preferably has a substoichiometric oxygen content. The method for making a tin-zinc mixed oxide coating by reactive cathode sputtering is for example known from DE 198 48 751 C1. The tin-zinc mixed oxide is preferably deposited with a target containing 25 wt % to 80 wt % of zinc, 20 wt % to 75 wt % of tin and 0 wt % to 10 wt % of antimony and production-related additives. The target particularly preferably contains 45 wt % to 75 wt % of zinc, 25 wt % to 55 wt % of tin and 1 wt % to 5 wt % of antimony and production-related additives of other metals. In the cathode sputtering process, the tin-zinc mixed oxide is deposited under the addition of oxygen as a reaction gas.

[0056] In this preferred embodiment, the layer thickness of the smoothing layer is preferably 3 nm to 20 nm, particularly preferably 4 nm to 12 nm. The smoothing layer preferably has a refractive index of less than 2.2.

[0057] In this preferred embodiment, the conductive layer preferably contains at least one metal, such as gold or copper, or an alloy, particularly preferably silver or a silver-containing alloy. However, the conductive layer may also contain other conductive materials known to those skilled in the art.

[0058] In an advantageous embodiment of the preferred embodiment, the conductive layer contains at least 90% by weight of silver, particularly preferably at least 99.9% by weight of silver. The conductive layer is preferably applied using conventional metal layer deposition methods, for example vacuum methods such as magnetic field-assisted sputtering.

[0059] In this preferred embodiment, the conductive layer preferably has a layer thickness of 8 nm to 25 nm, particularly preferably 10 nm to 20 nm. This is particularly advantageous with regard to the transparency and sheet resistance of the conductive layer.

[0060] In this preferred embodiment, the first adapter layer and / or the second adapter layer preferably contains zinc oxide ZnO 1-δ , where 0≤δ≤0.01, for example aluminum-doped zinc oxide (ZnO:Al). The zinc oxide is preferably deposited substoichiometrically with respect to oxygen in order to avoid reaction of excess oxygen with the silver-containing layer. The zinc oxide layer is preferably deposited by magnetic field-assisted sputtering. The target preferably contains 85% to 100% by weight of zinc oxide and 0% to 15% by weight of aluminum as well as production-related admixtures. The target particularly preferably contains 90% to 95% by weight of zinc oxide and 5% to 10% by weight of aluminum as well as production-related admixtures. Alternatively, the target preferably contains 95% to 99% by weight of zinc and 1% to 5% by weight of aluminum, wherein the deposition of the layers is carried out with the addition of oxygen as reaction gas. The layer thickness of the first and second adapter layers is preferably 3 nm to 20 nm, particularly preferably 4 nm to 12 nm.

[0061] In an advantageous design of this preferred embodiment, at least one functional layer comprises at least one blocking layer (blockerlayer). The blocking layer is in direct contact with the conductive layer and is arranged directly above or directly below the conductive layer. Therefore, no additional layer is arranged between the conductive layer and the blocking layer. The functional layer can also include two blocking layers, preferably one blocking layer is directly above the conductive layer and one blocking layer is directly below the conductive layer. Particularly preferably, each functional layer comprises at least one such blocking layer. The blocking layer preferably contains niobium, titanium, nickel, chromium and / or their alloys, particularly preferably nickel-chromium alloys. The thickness of the blocking layer is preferably 0.1nm to 2nm. This has obtained good results. The blocking layer directly below the conductive layer is particularly used to stabilize the conductive layer during temperature treatment and to improve the optical quality of the functional layer reflecting near-infrared radiation. The blocking layer directly above the conductive layer prevents the sensitive conductive layer from contacting the oxidizing reaction atmosphere during the deposition of the next layer (e.g., the second adapter layer, which preferably contains zinc oxide) by reactive cathode sputtering.

[0062] Typically, a block layer having a thickness of about 0.5 nm or even a few nanometers is used in the preferred embodiment.

[0063] In a further preferred embodiment, the functional layer reflecting near-infrared radiation has at least three functional layers arranged one above the other, and each functional layer comprises at least:

[0064] - an anti-reflection layer,

[0065] - a first adaptation layer above the antireflection layer, and

[0066] - a conductive layer above the first adaptation layer,

[0067] At least one of the functional layers comprises an antireflection layer comprising at least

[0068] - a layer of dielectric material having a refractive index less than 2.1, and

[0069] - A layer of optically high refractive material having a refractive index greater than or equal to 2.1.

[0070] The optical high refractive material layer may be arranged above or below the dielectric material layer having a refractive index less than 2.1. The optical high refractive material layer is preferably arranged above the dielectric material layer having a refractive index less than 2.1.

[0071] In this further preferred embodiment, the thickness of the optically high refractive material layer having a refractive index greater than or equal to 2.1 is preferably 10% to 99%, particularly preferably 25% to 75%, and most preferably 33% to 67% of the thickness of the antireflection layer comprising such an optically high refractive material layer.

[0072] In a particularly advantageous design of this further preferred embodiment, each antireflection layer arranged between two electrically conductive layers comprises at least one layer of a dielectric material having a refractive index of less than 2.1 and one layer of an optically high-refractive material having a refractive index greater than or equal to 2.1.

[0073] In this further preferred embodiment, the antireflection layer arranged between the two electrically conductive layers preferably has a layer thickness of 35 nm to 70 nm, particularly preferably 45 nm to 60 nm.

[0074] In this further preferred embodiment, the optically high-refractive material layer preferably has a refractive index n of 2.1 to 2.5, particularly preferably 2.1 to 2.3.

[0075] In this further preferred embodiment, the optically high refractive index material layer having a refractive index greater than or equal to 2.1 preferably contains at least one silicon / metal mixed nitride, particularly preferably at least one silicon / zirconium mixed nitride. This is particularly advantageous for the sheet resistance of the functional layer reflecting near-infrared radiation. The mixed silicon / zirconium nitride preferably has a dopant. The optically high refractive index material layer can contain, for example, aluminum-doped mixed silicon / zirconium nitride.

[0076] The silicon / zirconium mixed nitride is preferably deposited by magnetic field-assisted cathode sputtering with a target containing 40% to 70% by weight of silicon, 30% to 60% by weight of zirconium and 0% to 10% by weight of aluminum, as well as production-related admixtures. The target particularly preferably contains 45% to 60% by weight of silicon, 35% to 55% by weight of zirconium and 3% to 8% by weight of aluminum, as well as production-related admixtures. The deposition of the silicon / zirconium mixed nitride is preferably carried out with the addition of nitrogen as a reaction gas during the cathode sputtering process.

[0077] However, in this further preferred embodiment, the optical high refractive material layer may also include, for example, at least silicon / aluminum mixed nitride, silicon / hafnium mixed nitride or silicon / titanium mixed nitride. The optical high refractive material layer may alternatively contain, for example, Nb2O5, Bi2O3, TiO2, Zr3N4 and / or AlN.

[0078] In this further preferred embodiment, the thickness of the optically high refractive material layer is preferably from 3.5 nm to 69 nm.

[0079] The dielectric material layer having a refractive index of less than 2.1 preferably has a refractive index n of 1.6 to 2.1, particularly preferably 1.9 to 2.1.

[0080] The dielectric material layer of this further preferred embodiment preferably contains at least one oxide, such as tin oxide, and / or a nitride, particularly preferably silicon nitride. The dielectric material layer preferably has a thickness of 0.3 nm to 63 nm.

[0081] In this further preferred embodiment, the conductive layer preferably contains at least one metal, such as copper or gold, or an alloy, particularly preferably silver or a silver-containing alloy. However, the conductive layer may also contain other conductive materials known to those skilled in the art.

[0082] In an advantageous embodiment of this further preferred embodiment, the conductive layer contains at least 90% by weight of silver, particularly preferably at least 99.9% by weight of silver. The conductive layer is preferably applied using conventional metal layer deposition methods, for example vacuum methods such as magnetic field-assisted sputtering.

[0083] In this further preferred embodiment, the conductive layer preferably has a layer thickness of 8 nm to 25 nm, particularly preferably 10 nm to 19 nm. This is particularly advantageous with regard to the transparency, color neutrality and sheet resistance of the conductive layer.

[0084] The total layer thickness of all electrically conductive layers of this further preferred embodiment is preferably from 40 nm to 80 nm, particularly preferably from 45 nm to 60 nm.

[0085] In an advantageous design of this further preferred embodiment, the functional layer reflecting near infrared radiation contains at least one smoothing layer in at least one functional layer. The smoothing layer is arranged below one of the first adaptation layers, preferably between the antireflection layer and the first adaptation layer of at least one functional layer reflecting near infrared radiation. The smoothing layer is particularly preferably in direct contact with the first adaptation layer. The smoothing layer produces an optimization, in particular for smoothing the surface of the conductive layer subsequently applied above. The conductive layer deposited on a smoother surface has a higher transmittance and at the same time a lower sheet resistance.

[0086] In a particularly preferred design of this further preferred embodiment, each of the functional layers reflecting near-infrared radiation comprises a smoothing layer arranged below the first adapter layer, preferably between the antireflection layer and the first adapter layer.

[0087] In this further preferred embodiment, the smoothing layer preferably contains at least one amorphous oxide. The oxide may be amorphous or partially amorphous (and therefore partially crystalline), but not completely crystalline. The amorphous smoothing layer has a low roughness and thus forms a favorable smooth surface for the layer to be applied on the smoothing layer. The amorphous smoothing layer also achieves an improved surface structure of the layer deposited directly on the smoothing layer (which is preferably the first adaptation layer). The smoothing layer may contain, for example, at least one oxide of one or more of the elements tin, silicon, titanium, zirconium, hafnium, zinc, gallium and indium.

[0088] The smoothing layer of this further preferred embodiment particularly preferably contains amorphous mixed oxides. This smoothing layer most preferably contains tin / zinc mixed oxides. This mixed oxide may have a dopant. This smoothing layer may contain, for example, antimony-doped tin / zinc mixed oxides. This mixed oxide preferably has a substoichiometric oxygen content. The method for manufacturing a tin-zinc mixed oxide coating by reactive cathode sputtering is known, for example, from DE 19848751C1. This tin-zinc mixed oxide is preferably deposited with a target containing 25% to 80% by weight of zinc, 20% to 75% by weight of tin and 0% to 10% by weight of antimony and production-related additives. This target particularly preferably contains 45% to 75% by weight of zinc, 25% to 55% by weight of tin and 1% to 5% by weight of antimony and production-related additives of other metals. In the cathode sputtering process, the tin-zinc mixed oxide is deposited under the addition of oxygen as a reaction gas.

[0089] The layer thickness of the smoothing layer of this further preferred embodiment is preferably 3 nm to 20 nm, particularly preferably 4 nm to 12 nm. The smoothing layer preferably has a refractive index of less than 2.2.

[0090] In an advantageous design of this further preferred embodiment, each functional layer comprises a second adaptation layer arranged above the electrically conductive layer. This is particularly advantageous with regard to the sheet resistance of the functional layers reflecting near-infrared radiation.

[0091] In this further preferred embodiment, the first adapter layer and / or the second adapter layer preferably contains zinc oxide ZnO 1-δ , where 0≤δ≤0.01. The first adapter layer and / or the second adapter layer also preferably contain a dopant. The first adapter layer and / or the second adapter layer can, for example, contain aluminum-doped zinc oxide. The zinc oxide is preferably deposited substoichiometrically relative to oxygen to avoid reaction of excess oxygen with the silver-containing layer. The zinc oxide layer is preferably deposited by magnetic field-assisted sputtering. The target preferably contains 85% to 100% by weight of zinc oxide and 0% to 15% by weight of aluminum and production-related additives. The target particularly preferably contains 90% to 95% by weight of zinc oxide and 5% to 10% by weight of aluminum and production-related additives. Alternatively, the target preferably contains 95% to 99% by weight of zinc and 1% to 5% by weight of aluminum, wherein the deposition of the layer is carried out with the addition of oxygen as a reaction gas. The layer thickness of the first adapter layer and the second adapter layer is preferably 3nm to 20nm, particularly preferably 4nm to 12nm.

[0092] In a preferred design of this further preferred embodiment, an additional antireflection layer is applied above the uppermost functional layer. This additional antireflection layer improves the optical properties of the functional layer reflecting near-infrared radiation.

[0093] In this further preferred embodiment, the top anti-reflection layer is an anti-reflection layer arranged above the functional layer. In this further preferred embodiment, the bottom anti-reflection layer is an anti-reflection layer with the minimum distance from the surface of the functional layer to which the reflective infrared radiation is applied. The bottom anti-reflection layer is the anti-reflection layer of the bottom functional layer. The top and bottom anti-reflection layers are not arranged between two conductive layers. The top and / or bottom anti-reflection layer is preferably an optical high-refractive material layer with a refractive index greater than or equal to 2.1. The top and / or bottom anti-reflection layer particularly preferably contains at least one silicon / zirconium mixed nitride, such as aluminum-doped silicon / zirconium mixed nitride. However, the top and / or bottom anti-reflection layer may also contain a dielectric material with a refractive index less than 2.1, such as silicon nitride or tin oxide. For example, the top and / or bottom anti-reflection layer may also each contain an optical high-refractive material layer and a dielectric material layer with a refractive index less than 2.1. The thickness of the top and bottom anti-reflection layer is preferably 10nm to 40nm. This has obtained particularly good results.

[0094] In the advantageous design of this further preferred embodiment, at least one functional layer comprises at least one barrier layer. The barrier layer is in direct contact with the conductive layer and is arranged directly above or directly below the conductive layer. Therefore, no additional layer is arranged between the conductive layer and the barrier layer. The functional layer may also comprise two barrier layers, preferably one barrier layer directly above the conductive layer and one barrier layer directly below the conductive layer. Particularly preferably, each functional layer comprises at least one such barrier layer. The barrier layer preferably contains niobium, titanium, nickel, chromium and / or alloys thereof, particularly preferably a nickel-chromium alloy. The thickness of the barrier layer is preferably 0.1nm to 5nm, particularly preferably 0.1nm to 2nm. This obtains particularly good results. The barrier layer directly below the conductive layer is particularly used to stabilize the conductive layer during temperature treatment and to improve the optical quality of the functional layer reflecting near-infrared radiation. The barrier layer directly above the conductive layer prevents the sensitive conductive layer from contacting the oxidizing reaction atmosphere during the deposition of the next layer (e.g., the second adapter layer, which preferably contains zinc oxide) by reactive cathode sputtering.

[0095] Preferably, the functional layer reflecting thermal radiation contains a transparent conductive oxide (TCO). Such coatings are corrosion-resistant and can be used on exposed surfaces. The functional layer reflecting thermal radiation preferably contains indium tin oxide (ITO), which has proven to be particularly successful, in particular due to the low resistivity and low scattering in terms of sheet resistance. However, the functional layer reflecting thermal radiation can also contain, for example, indium-zinc mixed oxide (IZO), gallium-doped tin oxide (GZO), fluorine-doped tin oxide (SnO2:F) or antimony-doped tin oxide (SnO2:Sb). Most preferably, the functional layer reflecting thermal radiation contains indium tin oxide.

[0096] In a preferred embodiment, the functional layer reflecting thermal radiation is constructed as described in WO 2018 / 206236 A1 and, starting from the inner surface of the inner glass pane, comprises at least

[0097] - a blocking layer against alkali diffusion having a refractive index of at least 1.9,

[0098] - a dielectric lower antireflection coating having a refractive index of 1.3 to 1.8,

[0099] - a conductive layer,

[0100] - a dielectric barrier layer having a refractive index of at least 1.9 for regulating oxygen diffusion, and

[0101] - A dielectric upper antireflection coating having a refractive index of 1.3 to 1.8.

[0102] In this embodiment, the conductive layer of the functional layer reflecting thermal radiation contains a transparent conductive oxide, preferably indium tin oxide, indium zinc mixed oxide (IZO), gallium-doped tin oxide (GZO), fluorine-doped tin oxide (SnO2:F) or antimony-doped tin oxide (SnO2:Sb), particularly preferably indium tin oxide, and preferably has a refractive index of 1.7 to 2.3.

[0103] In this embodiment, the thickness of the conductive layer of the heat radiation reflecting functional layer is preferably 50 nm to 130 nm, particularly preferably 60 nm to 100 nm, for example 65 nm to 80 nm. This achieves particularly good results in terms of conductivity while maintaining sufficient optical transparency.

[0104] In this embodiment, the refractive index of the lower antireflection coating is preferably at most 1.8, particularly preferably 1.3 to 1.8. The thickness of the lower antireflection coating is preferably 5 nm to 50 nm, preferably 10 nm to 30 nm, for example 10 nm to 20 nm.

[0105] In this embodiment, the refractive index of the upper antireflection coating is preferably at most 1.8, particularly preferably 1.3 to 1.8. The thickness of the upper antireflection coating is preferably 10 nm to 100 nm, particularly preferably 30 nm to 70 nm, for example 45 nm to 55 nm.

[0106] In a particularly advantageous configuration, the heat radiation-reflecting functional layer in this embodiment has a lower antireflection layer below the electrically conductive layer and an upper antireflection layer above the electrically conductive layer.

[0107] The antireflection coating preferably contains an oxide or a fluoride, particularly preferably silicon oxide, aluminum oxide, magnesium fluoride or calcium fluoride. The silicon oxide may have a dopant and is preferably doped with aluminum (SiO2:Al), boron (SiO2:B), titanium (SiO2:Ti) or zirconium (SiO2:Zr). Alternatively, the layer may also contain, for example, aluminum oxide (Al2O3).

[0108] In a particularly advantageous configuration, the upper antireflection layer in this embodiment is the uppermost layer of the functional layer reflecting thermal radiation.

[0109] It has been shown that the oxygen content of the conductive layer, in particular if the conductive layer is based on TCO, has a significant influence on its properties, in particular transparency and conductivity. The production of glass sheets usually involves a thermal treatment, such as a thermal prestressing process, in which oxygen can diffuse into the conductive layer and oxidize it. In an advantageous design, the functional layer reflecting thermal radiation in this embodiment comprises a dielectric barrier layer with a refractive index of at least 1.9 between the conductive layer and the upper antireflection layer for regulating the diffusion of oxygen. The barrier layer serves to regulate the oxygen supply to an optimal level. Particularly good results are obtained if the refractive index of the barrier layer is between 1.9 and 2.5.

[0110] The dielectric barrier layer for regulating oxygen diffusion contains at least a metal, a nitride or a carbide. For example, the barrier layer can contain titanium, chromium, nickel, zirconium, hafnium, niobium, tantalum or tungsten, or a nitride or carbide of tungsten, niobium, tantalum, zirconium, hafnium, chromium, titanium, silicon or aluminum. In a preferred design, the barrier layer contains silicon nitride (Si3N4) or silicon carbide, in particular silicon nitride (Si3N4), with which particularly good results can be achieved. The silicon nitride can have a dopant and in a preferred additional form is doped with aluminum (Si3N4: Al), zirconium (Si3N4: Zr), titanium (Si3N4: Ti) or boron (Si3N4: B). During the temperature treatment after applying the functional layer reflecting thermal radiation, the silicon nitride can be partially oxidized. After the temperature treatment, the barrier layer deposited as Si3N4 then contains Si x N y O z , wherein the oxygen content is usually 0 atomic % to 35 atomic %.

[0111] The thickness of the barrier layer is preferably 5 nm to 20 nm, particularly preferably 7 nm to 12 nm, for example 8 nm to 10 nm. This adjusts the oxygen content of the conductive layer in a particularly advantageous manner.

[0112] In an advantageous design, the functional layer reflecting thermal radiation in this embodiment comprises a dielectric barrier layer preventing alkali diffusion below the conductive layer and optionally below the lower anti-reflective coating. The barrier layer reduces or prevents alkali ions from diffusing into the coating system from the glass substrate. Alkali ions can adversely affect the properties of the functional layer reflecting thermal radiation. In addition, the barrier layer interacting with the lower anti-reflective coating advantageously contributes to the optical regulation of the entire coating structure. The refractive index of the barrier layer is preferably at least 1.9. If the refractive index of the barrier layer is 1.9 to 2.5, particularly good results are obtained. The barrier layer preferably contains oxides, nitrides or carbides, preferably oxides, nitrides or carbides of tungsten, chromium, niobium, tantalum, zirconium, hafnium, titanium, silicon or aluminum, for example oxides such as Nb2O5, Bi2O3, TiO2, Ta2O5, Y2O3, ZrO2, HfO2, SnO2 or ZnSnO x , or nitrides such as AlN, TiN, TaN, ZrN or NbN. The barrier layer contains silicon nitride (Si3N4), which in a particularly preferred form gives particularly good results. The silicon nitride may have a dopant and in a preferred additional form is doped with aluminum (Si3N4:Al), titanium (Si3N4:Ti), zirconium (Si3N4:Zr) or boron (Si3N4:B). The thickness of the barrier layer is preferably 10nm to 50nm, more preferably 20nm to 40nm, for example 25nm to 35nm. The barrier layer is preferably the lowest layer of the layer stack; i.e. it is in direct contact with the substrate surface, where it can best exert its effect.

[0113] In an advantageous embodiment, the functional layer reflecting thermal radiation consists exclusively of layers having a refractive index of at least 1.9 or at most 1.8, preferably at most 1.6. In a particularly preferred embodiment, the functional layer reflecting thermal radiation consists exclusively of the aforementioned layers and does not contain any further layers. The functional layer reflecting thermal radiation then consists of the following layers, which are arranged in the specified order starting from the substrate surface:

[0114] - Barrier layer to prevent alkali diffusion

[0115] - Lower anti-reflective coating

[0116] -Conductive layer

[0117] - Barrier layer to regulate oxygen diffusion

[0118] - Anti-reflective coating on upper part.

[0119] The individual layers of the functional layer reflecting thermal radiation are deposited by methods known per se, preferably by magnetic field-assisted cathode sputtering. Sputtering is carried out in an inert gas atmosphere, such as argon, or in a reactive gas atmosphere, for example by adding oxygen or nitrogen. However, these layers can also be applied by other methods known to those skilled in the art, for example by gas phase deposition or chemical vapor deposition (CVD), by atomic layer deposition (ALD), by plasma enhanced chemical vapor deposition (PECVD) or by wet chemical methods.

[0120] In this embodiment, in an advantageous design, a barrier layer to prevent alkali diffusion is applied before the conductive layer. In an advantageous design, a lower antireflection coating is applied before the conductive layer and, if necessary, after the barrier layer. In an advantageous design, a barrier layer is applied after the conductive layer to regulate oxygen diffusion. In an advantageous design, an upper antireflection coating is applied after the conductive layer and, if necessary, after the barrier layer.

[0121] In order to select suitable materials and layer thicknesses in order to achieve a functional layer reflecting near-infrared radiation, a person skilled in the art can, for example, employ conventional simulations.

[0122] In order to select suitable materials and layer thicknesses in order to realize a functional layer which reflects thermal radiation, the person skilled in the art can also employ, for example, conventional simulations.

[0123] In the sense of the present invention, if the first layer is arranged above the second layer, this means that the first layer is arranged further away from the substrate on which the coating is applied than the second layer. In the sense of the present invention, if the first layer is arranged below the second layer, this means that the second layer is arranged further away from the surface of the glass sheet on which the functional layer is arranged than the first layer. The uppermost functional layer is the functional layer at the greatest distance from the surface of the glass sheet on which the functional layer is arranged. The lowermost functional layer is the functional layer at the smallest distance from the surface of the sheet on which the functional layer is arranged.

[0124] In the sense of the present invention, if a first layer is arranged above or below a second layer, this does not necessarily mean that the first layer and the second layer are in direct contact with each other. One or more additional layers may be arranged between the first layer and the second layer, unless explicitly excluded.

[0125] The indicated value of the refractive index is measured at a wavelength of 550 nm. Methods for determining the refractive index are known to those skilled in the art. The refractive index specified within the scope of the present invention can be determined, for example, by ellipsometry, wherein a commercially available ellipsometer can be used.

[0126] The functional layer reflecting near infrared radiation and the functional layer reflecting thermal radiation are transparent to visible light. "Transparent" in the sense of the present invention means that the overall transmittance of the windshield complies with legal requirements and preferably has a visible light transmittance of more than 70%, in particular more than 75%. "Opaque" therefore means a transmittance of less than 15%, preferably less than 5%, in particular 0%. The value of the light transmittance (TL) refers (as usual for automotive glazing) to the illuminant A, i.e. the visible part of sunlight at a wavelength of 380 nm to 780 nm, thereby essentially the visible spectrum of solar radiation.

[0127] The outer pane and the inner pane of the windshield preferably contain glass or consist of glass, particularly preferably flat glass, float glass, quartz glass, borosilicate glass, soda-lime glass, or contain or consist of transparent plastic, preferably hard transparent plastic, in particular polyethylene, polypropylene, polycarbonate, polymethyl methacrylate, polystyrene, polyamide, polyester, polyvinyl chloride and / or mixtures thereof.

[0128] The outer glass pane and the inner glass pane are preferably transparent and colorless. Independently of each other, the outer glass pane and the inner glass pane can be unprestressed, partially prestressed or prestressed. If at least one of the glass panes should be prestressed, this can be thermal or chemical prestressing.

[0129] The thickness of the outer and inner glass panes may vary greatly and be adapted to the requirements of the respective case. Preferably, glass panes with a standard thickness of 1.0 mm to 25 mm and preferably 1.4 mm to 2.1 mm are used. For example, the outer glass pane is 2.1 mm thick and the inner glass pane is 1.6 mm thick. However, the outer glass pane or in particular the inner glass pane may also be thin glass, for example with a thickness of 0.55 mm. The dimensions of the outer and inner glass panes may vary greatly and depend on the application.

[0130] The thermoplastic interlayer contains at least one thermoplastic or is composed of at least one thermoplastic, preferably polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) and / or polyethylene terephthalate (PET). However, the thermoplastic interlayer can also contain, for example, polyurethane (PU), polypropylene (PP), polyacrylate, polyethylene (PE), polycarbonate (PC), polymethyl methacrylate, polyvinyl chloride, polyacetate resin, casting resin, acrylate, fluorinated ethylene propylene, polyvinyl fluoride and / or ethylene tetrafluoroethylene or its copolymer or mixture. The thermoplastic interlayer can be designed by one or more thermoplastic films arranged on another, wherein the thickness of the thermoplastic film is preferably 0.25mm to 1mm, typically 0.38mm or 0.76mm. The thermoplastic interlayer can also be a film with functional properties, for example a film with acoustic damping properties.

[0131] In a preferred embodiment, the radiation source is arranged so that the first reflected radiation has a radiation component that is irradiated perpendicularly to the face of the vehicle user. Thus, it may be advantageous if the first reflected radiation is reflected from an area of ​​the windshield that is at least partially generated by the horizontal projection of the face of the vehicle user on the windshield. The first reflected radiation can preferably irradiate the face of the vehicle user in the horizontal direction or along a vertical line. This enables very good recognition of facial details of the vehicle user, in particular eye movements. Similarly, it is advantageous to arrange the radiation receiver to receive radiation (i.e., the third reflected radiation) reflected from the functional layer reflecting near-infrared radiation based on the second reflected radiation (which has a radiation component that has been vertically reflected from the face of the vehicle user). Advantageously, the third reflected radiation is reflected from an area of ​​the windshield that is at least partially generated by the horizontal projection of the face of the vehicle user on the windshield. The second reflected radiation can then preferably irradiate the functional layer reflecting near-infrared radiation to the face of the vehicle user in the horizontal direction or along a vertical line. This also enables very good recognition of facial details of the vehicle user, in particular eye movements. Similarly, it is advantageous to arrange the thermal imaging camera to receive thermal radiation reflected from the thermal radiation-reflecting functional layer based on thermal radiation, the thermal radiation having a radiation component emitted vertically from the face of the vehicle user. Advantageously, the thermal radiation emitted by the face of the vehicle user is reflected by an area of ​​the windshield at least partially resulting from the horizontal projection of the face of the vehicle user on the windshield.

[0132] In a preferred embodiment, a radiation receiver and a thermal imaging camera are provided for detecting a facial state of a vehicle user, wherein the vehicle user whose facial state is detected is preferably a driver of the vehicle.

[0133] In a preferred embodiment of the arrangement according to the invention, the vehicle user is the driver of the vehicle.

[0134] In a further preferred embodiment, for monitoring purposes, multiple faces can be captured by the radiation receiver and the thermal imaging camera. In particular, the radiation receiver and the thermal imaging camera are provided for detecting the facial state of the driver and the facial state of the passenger of the vehicle.

[0135] In a particularly advantageous design, the radiation source, the radiation receiver and the thermal imaging camera are centrally arranged on the dashboard of the vehicle. With this arrangement, multiple faces can be captured by the radiation receiver and the thermal imaging camera for monitoring purposes. More conveniently, in such an embodiment, the radiation receiver and the thermal imaging camera are provided for detecting the facial state of the driver and the facial state of the passenger.

[0136] Radiation sources, radiation receivers and thermal imaging cameras are usually separate components. However, these components can also be designed together as a module, i.e. an assembly unit.

[0137] In a preferred embodiment, the radiation source and the radiation receiver are designed as a module. In an alternative preferred embodiment, the radiation source and the thermal imaging camera are designed as a module. In a further alternative preferred embodiment, the radiation receiver and the thermal imaging camera are designed as a module. In a further alternative preferred embodiment, the radiation source, the radiation receiver and the thermal imaging camera are designed as a module.

[0138] The invention also extends to a driver assistance system with a monitoring function for at least one vehicle user of a vehicle, comprising an arrangement according to the invention. The driver assistance system further comprises at least one actuator and / or at least one signal output device, and an electronic control device, which is configured to determine information about the vehicle user based on the output signal of the radiation receiver and based on the output signal of the thermal imaging camera, and to output an electrical signal to at least one actuator for mechanical action and / or to at least one signal output device for outputting a visual and / or acoustic signal based on the determined information.

[0139] Furthermore, the present invention extends to a method for monitoring at least one vehicle user of a vehicle, in particular a method implemented in a driver assistance system according to the present invention, comprising the following steps:

[0140] a) emitting near infrared radiation onto a functional layer of the windshield reflecting near infrared radiation, so that the near infrared radiation reflected from the functional layer reflecting near infrared radiation irradiates the face of the vehicle user as first reflected radiation, wherein the first reflected radiation from the face of the vehicle user irradiates the functional layer reflecting near infrared radiation as second reflected radiation and is reflected from the functional layer reflecting near infrared radiation as third reflected radiation,

[0141] b) receiving third reflected radiation and receiving heat radiation reflected from the face of the vehicle user as reflected heat radiation emitted from the heat radiation reflecting functional layer of the windshield,

[0142] c) determine information about the vehicle user,

[0143] d) performing an action and / or outputting a visual and / or acoustic signal based on the information determined about the vehicle user.

[0144] It will be appreciated that in step b), the third reflected radiation is received by a radiation receiver for receiving near infrared radiation and the reflected thermal radiation is received by the thermal imaging camera.

[0145] The preferred embodiments of the arrangement according to the invention described above also apply correspondingly to the method according to the invention.

[0146] Furthermore, the invention extends to the use of the arrangement according to the invention in a driver assistance system for monitoring at least one vehicle user of a vehicle, in particular a motor vehicle, in land, water or air traffic.

[0147] The various embodiments of the present invention can be implemented alone or in any combination. In particular, the features mentioned above and explained below can be used not only in the specified combination, but also in other combinations or alone without departing from the scope of the present invention.

[0148] In the following, the invention is explained in more detail with the aid of drawings and examples of embodiments. Elements that are identical or have the same effect have the same reference numerals. In the simplified, not to scale illustration:

[0149] Figure 1 A schematic diagram showing the front part of a vehicle with a vehicle occupant using an arrangement according to the invention and a driver assistance system for monitoring at least one vehicle occupant,

[0150] Figure 2 shows a cross section through an embodiment of an arrangement according to the invention,

[0151] Figure 3 shows a cross section through another embodiment of an arrangement according to the invention,

[0152] Figure 4 shows a flow chart illustrating the method according to the invention for monitoring a vehicle driver based on near infrared,

[0153] Figure 5 A schematic diagram showing the functional blocks of a driver assistance system according to the present invention is shown,

[0154] Figure 6 shows the reflection spectrum of a windshield according to Example H,

[0155] Figure 7 shows the reflection spectrum of the windshield according to Example J,

[0156] Figure 8 The reflection spectrum of a windshield according to Example K is shown.

[0157] Figure 1 Shows a schematic diagram of a front portion of a vehicle 2 having a vehicle user 15 using an arrangement according to the present invention and a driver assistance system 100 for monitoring at least one vehicle user 15.

[0158] The arrangement 1 according to the invention comprises a windshield 6 of a vehicle 2 , which comprises an outer glass pane 7 and an inner glass pane 8 , which are firmly connected to one another via a thermoplastic intermediate layer 9 and have a functional layer 10 reflecting near-infrared radiation and a functional layer 11 reflecting thermal radiation.

[0159] The arrangement 1 further comprises a radiation source 3 for near infrared radiation, a radiation receiver 4 for near infrared radiation and a thermal imaging camera 5, such as Figure 12 , which can be arranged side by side, but can also be installed in one module or alternatively in two modules. The radiation source 3 and the radiation receiver 4 as well as the thermal imaging camera 5 are here installed, for example, in the rear area of ​​the console 25, where they are almost invisible to the vehicle user 15. The radiation source 3 is positioned and oriented so that the near-infrared radiation 12 emitted by the radiation source 3 is directed to the inner surface IV of the inner glass pane 8, where it is reflected by the functional layer 10 reflecting near-infrared radiation as first reflected radiation 13 towards the face 14 of the vehicle user 15. The near-infrared radiation 12 emitted by the radiation source 3 is reflected by the functional layer 10 reflecting near-infrared radiation in the first sub-area 20 of the windshield 6 and irradiates the face 14 of the vehicle user 15 from the front as first reflected radiation 13. In particular, the first reflected radiation 13 has a radiation component that irradiates the face 14 of the vehicle user 15 vertically (i.e. in the horizontal direction if the vehicle 2 is parked on a flat surface). The first reflected radiation 13 is reflected from the face 14 of the vehicle user 15 as the second reflected radiation 16 in the direction of the functional layer 10 reflecting near infrared radiation. In particular, the second reflected radiation 16 has a radiation component that is reflected vertically (i.e. in the horizontal direction if the vehicle 2 is parked on a flat surface) from the face 14 of the vehicle user 15. The second reflected radiation 16 is reflected from the functional layer 10 reflecting near infrared radiation to the radiation receiver 4 as the third reflected radiation 17. The third reflected radiation 17 is reflected by the second sub-area 21 of the windshield 6. The first sub-area 20 and the second sub-area 21 may partially overlap, completely overlap (i.e. be identical) or not overlap. The radiation receiver 4 is directed toward the inner surface IV of the inner glass pane 8 and can receive the third reflected radiation 17 reflected from the functional layer 10 reflecting near infrared radiation. The thermal imaging camera 5 is directed toward the inner surface IV of the inner glass pane 8. The heat radiation 18 emitted by the face 14 of the vehicle user 15 strikes the heat radiation reflecting functional layer 11 in the third sub-area 22 of the windshield 6 and is reflected by the latter as reflected heat radiation 19 in the direction of the thermal imaging camera 5 and can be received by the thermal imaging camera 5. The first sub-area 20, the second sub-area 21 and the third sub-area 22 may partially overlap, completely overlap (i.e. be identical) or not overlap. The first sub-area 20, the second sub-area 21 and the third sub-area 22 together form a reflection area 23 of the windshield 6. The first sub-area 20 preferably corresponds at least partially to the area of ​​the windshield 6 facing the face 14 of the vehicle user 15, i.e. the area resulting from the horizontal projection of the face 14 of the vehicle user 15 on the windshield 6. Similarly, the second sub-area 21 preferably corresponds at least partially to the area of ​​the windshield 6 facing the face 14 of the vehicle user 15. Similarly, the third sub-area 22 preferably corresponds at least partially to the area of ​​the windshield 6 facing the face 14 of the vehicle user 15.

[0160] Based on the vehicle user data recorded in this way, information about the vehicle user 15 can be determined in a particularly reliable manner, because on the one hand the first reflected radiation 13 reflected by the functional layer 10 has in particular a radiation component that irradiates the face 14 of the vehicle user 15 vertically, and on the other hand the third reflected radiation 17 reflected by the functional layer 10 has in particular a radiation component that is reflected vertically by the face 14 of the vehicle user 15. As a result, facial features, such as facial expressions and eye movements, can be determined particularly well and reliably. In addition, compared to the prior art arrangements based on near-infrared radiation, the arrangement according to the invention can be used to determine additional information about the vehicle user 15, such as the temperature of the face 14 of the vehicle user 15 and / or the thermal comfort of the vehicle user 15, by means of the thermal imaging camera 5. This is a particular advantage of the arrangement according to the invention. In addition, the radiation source 3, the radiation receiver 4 and the thermal imaging camera 5 can be arranged in the rear area of ​​the console 25, so that they can be easily integrated into the interior of the vehicle and do not interfere with the design of the vehicle interior.

[0161] Figure 2 A cross section through an embodiment of an arrangement 1 according to the invention is shown. Figure 2 In the embodiment shown in , the arrangement 1 comprises a radiation source 3 for emitting near-infrared radiation, a radiation receiver 4 for receiving near-infrared radiation, a thermal imaging camera 5 and a windshield 6. The windshield 6 comprises an outer glass pane 7 with an outer side surface I, an inner side surface II and an inner glass pane 8 with an outer side surface III and an inner side surface IV, which are connected to each other via a thermoplastic intermediate layer 9. In addition, the windshield 6 has a functional layer 10 that reflects near-infrared radiation and a functional layer 11 that reflects thermal radiation.

[0162] The outer glass pane 7 is made of, for example, green soda-lime glass and has a thickness of, for example, 2.1 mm. The inner glass pane 8 is made of, for example, soda-lime glass and has a thickness of, for example, 1.6 mm. The thermoplastic interlayer 9 is made of, for example, PVB and has a thickness of, for example, 0.76 mm.

[0163] exist Figure 2 In the embodiment of arrangement 1 according to the invention shown in , the functional layer 10 reflecting near-infrared radiation is designed as a coating on the inner surface II of the outer glass plate 7, and the functional layer 11 reflecting thermal radiation is designed as a coating on the inner surface IV of the inner glass plate 8.

[0164] The functional layer 10 reflecting near infrared radiation is configured, for example, as shown in Table 1 or 2. The functional layer 11 reflecting heat radiation is configured, for example, as shown in Table 3.

[0165] The radiation source 3, the functional layer 10 reflecting near-infrared radiation, the functional layer 11 reflecting thermal radiation, the thermal imaging camera 5 and the radiation receiver 4 are arranged so that the near-infrared radiation 12 emitted from the radiation source 3 can be reflected from the functional layer 10 reflecting near-infrared radiation to the face 14 of the vehicle user 15 as the first reflected radiation 13, the first reflected radiation 13 can be reflected from the face 14 of the vehicle user 15 to the functional layer 10 reflecting near-infrared radiation as the second reflected radiation 16, and the second reflected radiation 16 reflected from the functional layer 10 reflecting near-infrared radiation can be reflected to the radiation receiver 4 as the third reflected radiation 17 and can be received by the radiation receiver 4, and the thermal radiation 18 emitted from the face 14 of the vehicle user 15 can be reflected from the functional layer 11 reflecting thermal radiation to the thermal imaging camera 5 as the reflected thermal radiation 19 and can be received by the thermal imaging camera 5.

[0166] To simplify the explanation, Figure 2 Not shown are the vehicle user 15 , the near infrared radiation 12 emitted from the radiation source 3 , the first reflected radiation 13 , the second reflected radiation 16 , the third reflected radiation 17 , the thermal radiation 18 emitted from the face 14 of the vehicle user 15 , and the thermal radiation 19 reflected from the thermal radiation reflecting functional layer 11 .

[0167] Figure 3 A cross section through a further embodiment of an arrangement 1 according to the invention is shown. Figure 3 The implementation shown in Figure 2 The embodiment shown in FIG. 1 differs only in that the functional layer 10 reflecting near-infrared radiation is not designed as a coating on the inner surface II of the outer pane 7 , but as a coating on the outer surface III of the inner pane 8 .

[0168] Figure 4 The method according to the invention for monitoring at least one vehicle user is shown.

[0169] The method comprises at least the following method steps in the order given below:

[0170] S1 emits near-infrared radiation 12 onto the functional layer 10 reflecting near-infrared radiation of the windshield 6, so that the near-infrared radiation reflected from the functional layer 10 reflecting near-infrared radiation irradiates the face 14 of the vehicle user 15 as first reflected radiation 13, wherein the first reflected radiation 13 from the face 14 of the vehicle user 15 irradiates the functional layer 10 reflecting near-infrared radiation 10 as second reflected radiation 16, and is reflected from the functional layer 10 reflecting near-infrared radiation as third reflected radiation 17;

[0171] S2 receives the third reflected radiation 17 and receives the thermal radiation 18 reflected from the face of the vehicle user 15 as reflected thermal radiation 19 emitted from the thermal radiation-reflecting functional layer 11 ,

[0172] S3 determines information about the vehicle user 15,

[0173] S4 performs an action and / or outputs a visual and / or acoustic signal based on the information determined about the vehicle user 15 .

[0174] Figure 5 The functional components of a driver assistance system 100 according to the invention are schematically shown, the driver assistance system 100 having a monitoring function based on near infrared radiation and thermal radiation for at least one vehicle user 15. Thus, box E represents the part of the driver assistance system 100 involving the application of near infrared radiation and thermal radiation, box F represents the processing of the signal data captured thereby to determine information about the vehicle user 15, and box G represents possible actions based on the determined information about the vehicle user 15.

[0175] In block E, step A1, near infrared radiation is emitted by the radiation source 3 in the direction of the windshield 6 and is reflected by the functional layer 10 reflecting near infrared radiation in the direction of the face 14 of the vehicle user 15, and in step A2, the near infrared radiation reflected by the face 14 of the vehicle user 15 is reflected by the functional layer 10 reflecting near infrared radiation in the direction of the radiation receiver 4 and is received by the radiation receiver 4. Furthermore, in block E, step A3, thermal radiation emitted by the face 14 of the vehicle user 15 is reflected by the functional layer 11 reflecting thermal radiation to the thermal imaging camera 5 and is received by the thermal imaging camera 5. In block F, which is implemented in the vehicle 2 by an electronic control unit (ECU), information about the vehicle user 15 is determined using algorithms known per se, which in this case are, for example, the head position (B1) and the eye position (B2) of the vehicle user 15. Furthermore, identification of the vehicle user 15 is performed, for example, based on preset personalized personal data (B3). In addition, suitable algorithms can be used to determine further information about the vehicle user 15, such as the presence of fatigue or sleepiness (C1), which can be captured in particular based on a reduced eye movement frequency or excessive distraction (C2), which can be identified, for example, by a gaze direction that is not primarily directed forward and is therefore not used to guide the vehicle. The state thus determined can also be personalized in particular (C3) so that person-specific information can be determined, which presupposes that the vehicle user (B3) has been identified. In block G, as a result of determining information about the vehicle user 15 using the actuator, an intervention in the vehicle guidance can be performed. For example, if fatigue, in particular microsleep, is detected in the vehicle user 15 as the vehicle driver, a steering intervention for staying in the lane occurs (D1). Alternatively or additionally, an acoustic and / or visual signal (D2) can be output by a signaling device, such as a visual indication that sleepiness has been detected in the driver, possibly supported by an acoustic warning signal. Alternatively or additionally, for example, the air conditioning or heating system of the vehicle can be controlled based on the determined facial temperature of the vehicle user 15 (D3).

[0176] The invention is explained below with reference to the reflection spectra of windshields having a functional layer reflecting near-infrared radiation (Examples H and K) and of windshields having a functional layer reflecting thermal radiation (Example J).

[0177] The coating sequence and coating thickness in the windshield are given in Tables 1 to 3.

[0178] Table 1: Example H

[0179] Material thickness Soda-lime glass 2.1mm <![CDATA[SiZrN x ]]> 10.9nm <![CDATA[ZnSnO x ]]> 7.0nm ZnO 13.0nm Ag 9.5nm NiCr 0.2nm ZnO 12.0nm <![CDATA[SiZrN x ]]> 42.5nm <![CDATA[ZnSnO x ]]> 8.0nm ZnO 9.0nm Ag 9.5nm NiCr 0.3nm ZnO 10.0nm <![CDATA[Si3N4]]> 25.8nm <![CDATA[SiZrN x ]]> 21.3nm <![CDATA[ZnSnO x ]]> 7.0mm ZnO 14.0nm Ag 9.0nm NiCr 0.2nm ZnO 13.0nm <![CDATA[Si3N4]]> 9.9nm <![CDATA[SiZrN x ]]> 9.0nm PVB 0.76mm Soda-lime glass 1.6mm

[0180] Table 1 shows the layered structure of a windshield having a functional layer reflecting near infrared radiation, which is applied as a coating to the inside surface of the outer glass pane.

[0181] Table 2: Example J

[0182]

[0183]

[0184] Table 2 shows the layer structure of a windshield having a functional layer reflecting near infrared radiation, which is applied as a coating to the outer side surface of the inner glass pane.

[0185] Table 3: Example K

[0186]

[0187]

[0188] Table 3 shows the layered structure of a windshield having a functional layer reflecting thermal radiation, which is applied as a coating to the inside surface of the inner glass pane.

[0189] Reflectivity describes the fraction of the total radiation impinging on the windshield from the inside that is reflected. It is expressed as a % (based on 100% emitted radiation) or a unitless number between 0 and 1 (normalized to the emitted radiation). When plotted as a function of wavelength, it forms a reflectance spectrum.

[0190] The reflectance spectrum of Example H shows Figure 6 In, from Figure 6 It can be seen from the reflection spectrum shown in that the windshield according to Example H has a high reflectivity for near-infrared radiation in the wavelength range of 800nm ​​to 1600nm, and a low reflectivity for visible light.

[0191] The reflectance spectrum of Example J shows Figure 7 In, from Figure 7 It can be seen from the reflection spectrum shown in that the windshield according to Example J has a high reflectivity for near-infrared radiation in the wavelength range of 800nm ​​to 1600nm, and a low reflectivity for visible light.

[0192] The reflectance spectrum of Example K shows Figure 8 In, from Figure 8 It can be seen from the reflection spectrum shown in that the windshield according to Example K has a high reflectivity for thermal radiation in the wavelength range of 5 μm to 14 μm, preferably 7 μm to 14 μm, and particularly preferably 9 μm to 14 μm, and has a low reflectivity for visible light and near-infrared radiation in the wavelength range of 800 nm to 2500 nm.

[0193] List of reference numerals:

[0194] 1. Layout

[0195] 2 Vehicles

[0196] 3 Radiation sources

[0197] 4 Radiation Receiver

[0198] 5 Thermal Imaging Camera

[0199] 6 Windshield

[0200] 7 External glass panels

[0201] 8 Internal glass panels

[0202] 9 Thermoplastic middle layer

[0203] 10 Functional layer reflecting near-infrared radiation

[0204] 11 Functional layer that reflects thermal radiation

[0205] 12 Near infrared radiation emitted by radiation source 3

[0206] 13 First reflected radiation

[0207] 14 Face

[0208] 15 Vehicle users

[0209] 16 Second reflected radiation

[0210] 17 Third reflected radiation

[0211] 18 Emitted thermal radiation

[0212] 19 Reflected thermal radiation

[0213] 20 First sub-area

[0214] 21 Second sub-area

[0215] 22 Third sub-area

[0216] 23 Reflection Area

[0217] 24 Steering Wheel

[0218] 25 Console

[0219] 100 Driver Assistance Systems

Claims

1. An arrangement (1) of a driver assistance system (100) for a vehicle (2) for monitoring at least one vehicle user (15), comprising: - a radiation source (3) for emitting near-infrared radiation, - a radiation receiver (4) for receiving near infrared radiation, - Thermal imaging camera (5), and - a windshield (6) comprising an outer glass pane (7) having an outer surface (I) and an inner surface (II) and an inner glass pane (8) having an outer surface (III) and an inner surface (IV), which are connected to one another via a thermoplastic intermediate layer (9), wherein a functional layer (10) reflecting near-infrared radiation is arranged on the inner surface (II) of the outer glass pane (7) or on the outer surface (III) of the inner glass pane (8), and a functional layer (11) reflecting thermal radiation is arranged on the inner surface (IV) of the inner glass pane (8), The radiation source (3), the functional layer (10) reflecting near-infrared radiation, the functional layer (11) reflecting thermal radiation, the thermal imaging camera (5) and the radiation receiver (4) are arranged so that: Near infrared radiation (12) emitted from the radiation source (3) can be reflected by the functional layer (10) reflecting near infrared radiation as first reflected radiation (13) toward the face (14) of the vehicle user (15), the first reflected radiation (13) can be reflected by the face (14) of the vehicle user (15) as second reflected radiation (16) toward the functional layer (10) reflecting near infrared radiation, and the second reflected radiation (16) reflected by the functional layer (10) reflecting near infrared radiation as third reflected radiation (17) can be reflected toward the radiation receiver (4) and can be received by the radiation receiver (4), The thermal radiation (18) emitted by the face (14) of the vehicle user (15) is reflected by the thermal radiation reflecting functional layer (11) as reflected thermal radiation (19) to the thermal imaging camera (5) and can be received by the thermal imaging camera (5).

2. Arrangement (1) according to claim 1, wherein the functional layer (10) reflecting near-infrared radiation is arranged on the inner surface (II) of the outer glass pane (7).

3. Arrangement (1) according to claim 1, wherein the functional layer (10) reflecting near-infrared radiation is arranged on the outer side surface (III) of the inner glass pane (8).

4. The arrangement (1) according to claim 1, wherein the functional layer (10) reflecting near-infrared radiation and the functional layer (11) reflecting thermal radiation extend over substantially the entire area of ​​the windshield (6).

5. The arrangement (1) according to claim 1, wherein the functional layer (10) reflecting near-infrared radiation and the functional layer (11) reflecting thermal radiation are arranged in a sub-region of the windshield (6).

6. An arrangement (1) according to any one of claims 1 to 5, wherein the functional layer (10) reflecting near-infrared radiation comprises a layer system having at least one metal layer, in particular at least one metallic silver layer, embedded between dielectric oxide or nitride layers. 7 . The arrangement ( 1 ) according to claim 6 , wherein the functional layer ( 10 ) reflecting near-infrared radiation comprises a layer system having three silver layers embedded between dielectric oxide or nitride layers.

8. An arrangement (1) according to any one of claims 1 to 7, wherein the functional layer (11) reflecting thermal radiation contains a transparent conductive oxide, preferably indium tin oxide, indium zinc mixed oxide (IZO), gallium-doped tin oxide (GZO), fluorine-doped tin oxide (SnO2:F) or antimony-doped tin oxide (SnO2:Sb), particularly preferably indium tin oxide.

9. An arrangement (1) according to any one of claims 1 to 8, wherein a radiation receiver (4) and a thermal imaging camera (5) are provided for detecting a facial state of a vehicle user (15).

10. The arrangement (1) according to any one of claims 1 to 9, wherein the vehicle user (15) is a driver of the vehicle (2).

11. An arrangement (1) according to any one of claims 1 to 10, wherein a radiation receiver (4) and a thermal imaging camera (5) are provided for detecting the facial state of a driver and the facial state of a passenger of the vehicle (2).

12. An arrangement (1) according to any one of claims 1 to 11, wherein the radiation source (3) and the radiation receiver (4) are designed as a module, or wherein the radiation source (3) and the thermal imaging camera (5) are designed as a module, or wherein the radiation receiver (4) and the thermal imaging camera (5) are designed as a module, or wherein the radiation source (3), the radiation receiver (4) and the thermal imaging camera (5) are designed as a module, or wherein the radiation source (3), the radiation receiver (4) and the thermal imaging camera (5) are designed as a module.

13. A driver assistance system (100) having a monitoring function for at least one vehicle user (15) of a vehicle (2), comprising: - an arrangement (1) according to any one of claims 1 to 12, - at least one actuator and / or at least one signal output device, - an electronic control device, which is configured to determine information about the vehicle user (15) based on the output signal of the radiation receiver (4) and the output signal of the thermal imaging camera (5), and output an electrical signal to at least one actuator to perform a mechanical action and / or to at least one signal output device to output a visual and / or acoustic signal based on the determined information.

14. A method for monitoring at least one vehicle user (15) of a vehicle (2), comprising the following steps: a) emitting near infrared radiation (12) onto a functional layer (10) of a windshield (6) that reflects near infrared radiation, so that the near infrared radiation reflected from the functional layer (10) that reflects near infrared radiation irradiates the face (14) of a vehicle user (15) as first reflected radiation (13), wherein the first reflected radiation (13) from the face (14) of the vehicle user (15) irradiates the functional layer (10) that reflects near infrared radiation as second reflected radiation (16) and is reflected by the functional layer (10) that reflects near infrared radiation as third reflected radiation (17); b) receiving third reflected radiation (17) and receiving heat radiation (18) emitted from the heat radiation reflecting functional layer (11) of the windshield (6) as reflected heat radiation (19) reflected from the face of the vehicle user (15); c) determining information about the vehicle user (15), d) performing an action and / or outputting a visual and; or acoustic signal based on the information determined about the vehicle user (15).

15. Use of an arrangement (1) according to any one of claims 1 to 12 in a driver assistance system (100) for monitoring at least one vehicle user (15) of a vehicle (2) in land, water or air traffic.

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