Heating system for heating a living being

The invention relates to a heating system for heating a living being, for instance, a person (2) within a vehicle (1) being preferentially a hybrid car or an electric car. The heating system comprises an infrared laser system (5, 6) for illuminating the living being with infrared laser light, thereby heating the living being. Thus, heating radiation is used, which has a high collimation and which can be focused relatively easily. The heating can therefore be confined to a certain region, in which the living being is located. The heating can even be confined to the living being or to parts of the living being only. This more focused heating allows for a reduction of the energy consumption.

FIELD OF THE INVENTION

The invention relates to a heating system, a heating method and a heating computer program for heating a living being. The invention relates further to a camera system and a driver assist system for cooperating with the heating system.

BACKGROUND OF THE INVENTION

US 2010/0187211 A1 discloses a vehicle cabin heating system. An infrared heater heats a target surface in front of the infrared heater within a vehicle cabin interior space, wherein a temperature sensor disposed in front of the infrared heater detects a temperature. A controller is operatively coupled to the infrared heater, in order to selectively operate the infrared heater to a target surface temperature within the vehicle cabin interior space, whenever an estimated surface temperature of a target surface, which is determined based on the detected temperature, falls below a prescribed temperature range below the target surface temperature. This kind of heating the vehicle cabin consumes much energy.

FIELD OF THE INVENTION

It is an object of the present invention to provide a heating system, a heating method and a heating computer program for heating a living being, which allow reducing the energy consumed for heating the living being. It is a further object of the present invention to provide a camera system and a driver assist system for cooperating with the heating system.

In a first aspect of the present invention a heating system for heating a living being is presented, wherein the heating system comprises an infrared laser system for illuminating the living being with infrared laser light, thereby heating the living being.

Since the heating system comprises a laser system for illuminating the living being with infrared laser light, heating radiation is used, which has a high collimation and which can be focused relatively easily. The heating can therefore be confined to a certain region, in which the living being is located. The heating can even be confined to the living being or to parts of the living being only. For instance, the heating can be confined to very temperature sensitive parts of a person like the face or the feet of the person. This more focused heating within the vehicle allows for a reduction of the energy consumed by heating the interior of the vehicle.

The living being is preferentially a person, wherein the infrared laser system is preferentially adapted such that by heating the person the well being of the person is increased. However, the living being can also be an animal or a plant.

The infrared laser system can comprise one or several infrared lasers. In particular, the infrared laser system can comprise several infrared lasers for illuminating the living being in different directions. Preferentially, the infrared laser system comprises one or several vertical-cavity surface-emitting lasers (VCSELs). VCSELs are relatively compact and small and can easily be arranged at different locations within, for instance, a cabin of a vehicle. For example, several VCSELs can easily be arranged at different locations within a car, in order to illuminate a person from different directions.

The heating system is preferentially adapted to be used for heating a person in a vehicle. The vehicle preferentially comprises a window, wherein the infrared laser system can comprise one or several infrared lasers being adapted to be located next to the window. The infrared laser system can be adapted to heat also the window, in particular, for avoiding condensation on the window. The window is, for instance, a windshield of the vehicle.

For heating the window it can be illuminated with infrared laser light of the infrared laser system. For instance, the infrared laser system can comprise several infrared lasers, wherein some infrared lasers can be controlled to illuminate the window and other infrared lasers can be controlled to illuminate the person. Alternatively, the infrared laser system can be controlled to illuminate the window in a first operational state and to illuminate the person in a second operational state, wherein a user can switch between the two operational states or wherein it can be switched automatically between the two operational states. The infrared laser system can be adapted to couple the infrared laser light into the window which may act as a light guide. Within the window the light is guided by total internal reflection, wherein the total internal reflection may be frustrated by ice or water condensation on the window such that light outcoupling is high at regions where heating is needed. Additionally, parts of the window can be adapted ensure that light is coupled out of the window at desired locations by frustrated total internal reflection. Moreover, the infrared laser system can be adapted to heat the window by using the waste heat of the infrared laser system. For instance, a heat conducting connection can be provided between the window and the infrared laser system for transferring the waste heat from the infrared laser system to the window. This heat conducting connection can be a metal connection. Furthermore, the infrared laser system can comprise a cooling unit for cooling the infrared laser system, wherein the heated exhausted air of the cooling unit of the infrared laser system can be directed to the window for heating the window.

The infrared laser system is preferentially adapted to illuminate the living being with near or far infrared light. Moreover, the infrared laser system can be adapted to provide a 300 W heating.

It is also preferred that the infrared laser system comprises an array, in particular, a line, of infrared lasers. Preferentially, the array of infrared lasers is bonded to a flexible substrate. An array, in particular, a line, of infrared lasers bonded to a flexible substrate can relatively easily be arranged at desired locations within, for example, a cabin of a vehicle. For instance, one or several lines of infrared lasers can be arranged at the borders of a windshield of a vehicle.

The living being is preferentially a person within a vehicle, wherein the vehicle comprises a feet region, in which the feet of the person are to be located, wherein the infrared laser system is adapted to be arranged next to or within the feet region for illuminating the feet of the person with infrared laser light.

In a preferred embodiment, the heating system further comprises a) a presence signal providing unit for providing a presence signal being indicative of whether a living being is present such that the living being is illuminatable by the infrared light from the infrared laser system and b) a control unit for controlling the infrared laser system depending on the presence signal. The presence signal providing unit is preferentially an image providing unit for providing an image of the living being as the presence signal such that the control unit is preferentially adapted to control the infrared laser system depending on the provided image. The image providing unit comprises preferentially a camera system for acquiring an image from the living being. The camera system is preferentially adapted to detect infrared light reflected from the living being for acquiring the image. The camera system comprises, for example, a charge-couple device (CCD) camera or a complementary metal oxide semiconductor (CMOS) camera. The camera can also be a thermal camera.

The presence signal providing unit can also be another unit for providing a presence signal like a motion sensor or a receiving unit for receiving the presence signal, in particular, an image from a camera system, via a wired or wireless data connection and for providing the received presence signal.

It is further preferred that the control unit is adapted to determine whether a living being is present such that the living being can be illuminated by the infrared light from the infrared laser system depending on the presence signal, in particular, depending on the provided image, and to control the infrared laser system to provide the infrared laser light, if the control unit has determined that the living being is present, in particular, located within a vehicle, such that the living being can be illuminated by the infrared light. The heating system can therefore be adapted to heat regions of, for instance, a cabin of a vehicle, to which the infrared laser light is to be directed, only if in these regions a living being is really present. This further reduces the energy consumption.

The presence signal can be further indicative of the location of the living being to be heated, wherein the control unit can be adapted to determine the location of the living being depending on the provided presence signal and to control the infrared laser system to provide the infrared laser light to the determined location of the living being. The infrared laser system can comprise laser optics for dynamically directing the laser light to the location of the living being. The infrared laser light can therefore be directed to the living being, even if the living being moves.

In an embodiment the presence signal providing unit is an image providing unit for providing an image of the living being as the presence signal, wherein the control unit is adapted to detect predefined regions on the living being from the provided image and to control the infrared laser system to provide the infrared laser light to the detected predefined regions. The predefined regions are, for example, most heat sensitive body parts like the face or the hands. The predefined regions can also be bare skin regions, which can be detected in the acquired image. Since not the entire living being is illuminated with infrared laser light, but only certain predefined regions, in particular, predefined highly heat sensitive regions of the living being, the energy consumption can be further reduced.

The control unit can also be adapted to determine a temperature value being indicative of a temperature of the living being from the provided image and to control the infrared laser system depending on the determined temperature value. For instance, the control unit can be adapted to analyze the provided image for detecting a reaction of the skin of a person on the infrared light. In an embodiment, it is detected, for instance, whether blood supply is increased by the radiation. Since the blood supply is related to temperature, the respective blood supply value can be regarded as being a temperature value, which can be used by the control unit to adjust the infrared heat.

It is further preferred that the living being is a driver of a vehicle, wherein the heating system comprises an attention signal providing unit for providing an attention signal, if the driver's attention is to be attracted, and a control unit for controlling the infrared laser system depending on the provided attention signal. For instance, the attention signal providing unit can be a driver assist system like a lane departure system or a pre-collision warning system, wherein the attention signal providing unit can provide an attention signal, if the lane has been departed or a collision is likely to occur. The attention signal providing unit can be such a driver assist system or it can be a receiving unit, which receives a corresponding attention signal from a driver assist system and which provides this received attention signal. The attention signal is preferentially an electrical signal having predefined characteristics or which is provided only through a predefined channel such that the electrical signal can be identified as being an attention signal. Thus, if a dangerous situation has been detected, the attention of the driver can be achieved by directing, for instance, pulses of heat to the driver.

The heating system can further comprise a temperature sensor for sensing an ambient temperature like a temperature within a vehicle, wherein the control unit can be adapted to control the infrared laser system depending on the sensed temperature. The heating system can also comprise an input unit allowing a user to input a desired temperature, wherein the control unit can be adapted to control the infrared laser system depending on the input desired temperature and optionally depending on the measured temperature.

In a further aspect of the present invention a camera system for cooperating with a heating system is presented, wherein the heating system comprises a control unit for controlling the infrared laser system depending on a presence signal, wherein the camera system is adapted to acquire an image of the living being and to send the acquired image as the presence signal to the heating system for allowing the control unit of the heating system to control the infrared laser system of the heating system depending on the acquired image.

In a further aspect of the present invention a driver assist system for cooperating with a heating system is presented, wherein the driver assist system is adapted to detect a dangerous situation, to generate an attention signal, if a dangerous situation has been detected, and to send the attention signal to the heating system, in order to allow the control unit of the heating system to control the infrared laser system of the heating system depending on the attention signal.

In a further aspect of the present invention a vehicle comprising a heating system as defined in claim1is presented. The vehicle comprises preferentially an electric motor for driving the vehicle. In an embodiment, the vehicle is a hybrid vehicle or a pure electric vehicle. Preferentially, the heating system comprises several infrared lasers being distributed within the vehicle. The infrared lasers are preferentially distributed over dimensions covering a significant part of the space within the vehicle. The significant part has preferentially a minimum length of 15 cm in at least one direction. The several infrared lasers can be arranged in lines located at the borders of a windshield of the vehicle.

In a further aspect of the present invention a heating method for heating a living being is presented, wherein the heating method comprises illuminating the living being with infrared laser light by an infrared laser system, thereby heating the living being.

In a further aspect of the present invention a heating computer program for heating a living being is presented, wherein the heating computer program comprises program code means for causing a heating system as defined in claim1to carry out the heating method as defined in claim14, when the computer program is run on a computer controlling the heating system.

It shall be understood that the heating system of claim1, the camera system of claim10, the driver assist system of claim11, the vehicle of claim12, the heating method of claim14and the heating computer program of claim15have similar and/or identical preferred embodiments, in particular, as defined in the dependent claims.

It shall be understood that a preferred embodiment of the invention can also be any combination of the dependent claims with the respective independent claim.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1shows schematically and exemplarily an embodiment of a vehicle1comprising a heating system22for heating a living being2being, in this embodiment, a person within the vehicle1. The heating system, which is schematically and exemplarily shown in more detail inFIG. 2, comprises an infrared laser system5,6for illuminating the person2located within the vehicle1with infrared laser light12,15, thereby heating the person2. The vehicle1is a hybrid car or an electric car comprising an electric motor16for driving the vehicle.

In this embodiment, the infrared laser system comprises two groups5,6of infrared lasers, a first group5located close to a head region21within the vehicle1, in which the head20of the person2is to be located, and a second group6close to a feet region10within the vehicle1, in which the feet11of the person2are to be located.

The two groups5,6of infrared lasers can each be arranged in a line, which may be straight or curved. The several lasers of the groups5,6of the infrared laser system illuminate the person2in different directions and are VCSELs.

The first group5of lasers is located next to a windshield9of the vehicle1. For instance, it can be arranged next to or at the border of the windshield9, i.e. directly above, below or at the side of the windshield9. The first group5of lasers can be adapted to illuminate also the windshield9with infrared light, in order to avoid condensation on the windshield9. Moreover, alternatively or in addition the first group5of lasers can be adapted to direct waste heat generated by the lasers to the windshield9, in order to avoid condensation on the windshield9. Furthermore, a cooling unit of the infrared laser system can produce heated exhausted air, which can be directed to the window for heating the window. The second group6of lasers is arranged next to or within the feet region10for illuminating the feet11of the person2with the infrared laser light.

The infrared laser system5,6is adapted to illuminate the person2with near infrared light12,15having a wavelength within the wavelength region of, for instance, 850 to 1400 nm. Moreover, the infrared laser system5,6is adapted to provide a heating of about 300 W. In other embodiments, the infrared laser system can also be adapted to illuminate the person2with infrared laser light within another wavelength range. For instance, the person2can be illuminated with far infrared light. Furthermore, in another embodiment the infrared laser system can be adapted to provide another heating power being larger or smaller than 300 W.

The good collimation of the laser radiation enables the heating system for confined heating of the relevant parts of the person and at the same time allows distributing the laser sources over a wide area. The advantage of distributing the sources over a wide area is twofold: First of all it distributes the waste heat produced in the lasers thus facilitating cooling as well as a secondary use of the waste heat, for example, for heating the window. Secondly it helps significantly to comply with laser safety standards as laser radiation coming from a distributed source causes much less harm as it cannot be refocused on a single point.

The person2is a driver sitting on a seat3and steering the vehicle1by using a steering wheel4. The heating system22comprises a camera system7being an image providing unit for providing an image of the person2, if the person2is sitting on the seat3. The camera system7is adapted to detect infrared light14reflected from the person2for acquiring the image. The camera system7comprises, for example, a CCD camera or a CMOS camera. The heating system22further comprises a control unit13, which is schematically and exemplarily shown inFIG. 2. The control unit13is adapted to control the infrared laser system5,6depending on the acquired image. In particular, the control unit13is adapted to determine whether the person2is located within the vehicle1such that the person2can be illuminated by the infrared light from the infrared laser system5,6depending on the acquired image, i.e. the control unit13is adapted to determine whether the person2sits on the seat3. The control unit13is further adapted to control the infrared laser system5,6such that the infrared laser light is provided, if the control unit13has determined that the person2is located within the vehicle1such that the person2can be illuminated by the infrared laser light. Thus, the illumination with infrared laser light can be switched on or off depending on whether a person is sitting in front of the infrared laser system5,6.

In another embodiment this information about whether a person is present within the vehicle or not can also be obtained from another presence signal providing unit like a separate car management system. For instance, the control unit can be adapted to control the infrared laser system to provide the infrared laser light, if the control unit has received a signal from the car management system indicating that a living being is present within the vehicle and can be illuminated by the infrared laser light. For example, the car management system can receive the information whether a person is sitting on a certain seat from, for instance, pressure sensitive sensors incorporated within the respective seat, wherein this information can be provided to the control unit. This pressure sensitive sensor can also be regarded as being a presence signal providing unit.

The control unit13is further adapted to detect predefined regions on the person2from the acquired image and to control the first group5of lasers such that the infrared laser light is provided to the detected predefined regions. The predefined regions are, for example, heat sensitive body parts like the face or the hands. The predefined regions can also be bare skin regions, which can be detected in the acquired image. The infrared laser system preferentially comprises infrared optics for directing the infrared laser light to the detected predefined regions, wherein the infrared optics are controlled by the control unit13for directing the laser light to the detected predefined regions. For detecting the predefined regions in the acquired image known image processing techniques, in particular, segmentation techniques like thresholding and comparisons with known shapes of the predefined regions can be used.

The control unit13is further adapted to determine a temperature value being indicative of a temperature of the person2from the acquired image and to control the infrared laser system depending on the determined temperature value. In this embodiment, the control unit13is adapted to analyze the acquired image, in order to detect the reaction of the skin of the person2on the infrared light. It is detected whether the blood supply is increased by the infrared radiation, wherein a value can be generated being indicative of the increased blood supply. Since the blood supply is related to temperature, the generated value is a temperature value being indicative of the temperature of the person2, wherein this temperature value can be used for adjusting the infrared heat applied to the person2.

For example, the control unit13can be adapted to use the software algorithms of the software Vital Signs Camera of the company Philips, which detect small variations in blood flow from an image acquired by a camera. In another embodiment, the control unit and the lasers can be adapted to determine the blood flow by investigating the laser light being scattered back from the skin as disclosed in the article “A Comparative Study for the Assessment on Blood Flow Measurement Using Self-Mixing Laser Speckle Interferometer” by S. K. Ozdemir et al., IEEE Transactions on Instrumentation and Measurement, volume 57, issue 2, pages 353 to 363 (2008), which is herewith incorporated by reference. In particular, a Doppler shift of the scattered light with respect to undisturbed laser light can be determined, wherein the amount of photons having a Doppler shift can be a measure for total blood perfusion. Thus, a reaction of the skin exposed to the infrared light can be detected and the intensity of the infrared laser light can be adjusted accordingly.

The heating system further comprises an attention signal providing unit8for providing an attention signal, if the driver's attention should be attracted, wherein the control unit13is adapted to control the infrared laser system5,6depending on the provided attention signal. In this embodiment, the attention signal providing unit8is driver assist system such as a lane departure system or a pre-collision warning system, which is adapted to provide an attention signal, if the lane has been departed or if a collision could occur. The control unit13is preferentially adapted to control the infrared laser system5,6to direct pulses of heat to the driver2, if it receives an attention signal from the driver assist system8, in order to attract the attention of the driver2, if a dangerous situation is detected. The pulses of heat directed to the driver2for attracting the driver's attention should of course be sensible by the driver2, but not damage the driver's skin. The infrared laser system5,6is therefore preferentially operated at a predefined safety level such that the skin is not damaged, i.e. such that the energy level of the heat pulses does not cause too high skin temperatures. In an embodiment, the heat pulses are directed towards the driver with a relatively low frequency between 0.1 to 10 Hz, in order to attract the driver's attention.

The heating system22further comprises temperature sensors17,18for measuring the temperature in the head region21and the feet region10, respectively. The measured temperatures are provided to the control unit13for allowing the control unit13to control the infrared laser system5,6under consideration of the temperature within the cabin of the vehicle. The heating system22further comprises an input unit19, which may be a part of the control unit13or which may be a separate unit. The input unit allows a user to input a desired temperature, wherein the control unit13is adapted to control the infrared laser system5,6depending on the input desired temperature. In an embodiment, different persons can input different desired temperatures, wherein the control unit13is adapted to individually control the infrared laser system5,6such that each person is heated as desired. The control unit13can comprise control rules defining characteristics of the infrared laser light like the intensity, the wavelength, the emission direction, et cetera depending on the measured cabin temperature, the desired temperature, an optional further information obtained from, for instance, a camera system and/or a driver assist system.

In the following an embodiment of a heating method for heating a living being will exemplarily be described with reference to a flowchart shown inFIG. 3.

In step101, the infrared laser system illuminates the interior of the vehicle and the camera system acquires an image of the interior of the vehicle. In step102, the control unit determines whether persons are located within the vehicle. In particular, the control unit determines in front of which infrared lasers a person is present. If persons are not present in front of any laser, a heating is not necessary and the heating method ends in step107. In step103, the control unit detects predefined regions on the persons from the acquired image. In particular, the control unit detects most heat sensitive body parts like the face or the hands. The predefined regions can also be bare skin regions, which can be detected in the acquired image. Moreover, in step104the persons within the vehicle can input desired temperatures via the input unit and in step105the temperature sensors measure the temperatures within the cabin of the vehicle. In step106, the control unit controls the infrared laser system such that only lasers are activated, in front of which really a part of a person is present. Moreover, the control unit controls the infrared laser light emitted by the infrared laser system by using control rules defining characteristics of the infrared laser light depending on the input desired temperature, the measured temperature within the cabin and the locations of the detected predefined regions like the locations of the face and the hands of the person. Steps101to106can be performed in a loop such that the control of the infrared laser system can be updated, if a new image is acquired by the camera system, if the desired temperature has been modified via the input unit or if the temperature within the cabin measured by the temperature sensors has been changed.

It should be noted that the described heating method is only an exemplary embodiment of a heating method for heating a living being within a vehicle. In other embodiments the heating method can comprise other steps describing the heating of a living being within the vehicle by using infrared laser light of an infrared laser system. For instance, the infrared laser system can be controlled depending on an attention signal of a driver assist system, the acquired image can be used for generating a temperature value, which may be related to an increase of blood supply caused by the infrared radiation, wherein the infrared laser system can be controlled based on the temperature value, the heating method can be stopped after a corresponding input into the input unit by a user, et cetera.

According to the article “Assessment of man's thermal comfort in practice” by P. O. Fanger, British Journal of Industrial Medicine, volume 30, pages 313 to 324 (1973) thermal comfort depends on four factors: a) the temperature of air around the person, b) the air velocity, c) the radiation temperature of the surrounding and d) the clothing. Thermal comfort in modern cars is ensured by automatic climate systems. These systems adjust the air temperature and the air velocity inside the compartment of the car. Since the car body itself is usually around five degrees colder due to strong convective cooling induced by the driving velocity, the air temperature inside the car often needs to be significantly higher than for instance a comfortable air temperature in a house.

Fortunately heat is omnipresent in conventional combustion-engine cars. Only 30 percent of the energy contained in the fuel is transformed into mechanical energy to drive the car. The remaining 70 percent is wasted energy released in the form of heat. It is straightforward to use part of this heat and redirect it into the vehicle's compartment heating up the air.

Electric vehicles have, however, a very good conversion ratio of electrical to mechanical energy. And, as a side effect, heating energy is not abundantly present anymore. Hence systems to heat up the car's compartment need to be electrified as well. Unfortunately these electric heating systems are so energy demanding that the battery is drained quickly, reducing the range of car. In extreme cases the reduction is reported to be 30 percent, which is not acceptable given the limited range of these vehicles.

For solving this problem in known electric cars most heating systems are equipped with a so-called super economic mode. Set in this mode, the climate system reduces its energy demand at the cost of thermal comfort inside the compartment.

The heating system described above with reference toFIGS. 1 and 2uses infrared laser light, in particular, near infrared laser light, instead of, for instance, hot air, which is often used in climate systems. The feeling of thermal comfort can be realized with less power, wherein the solution is highly directive, i.e. only areas are heated, which really need to be heated, and the effect is instantaneous. The heating system is adapted to directly heat up the persons inside the vehicle. It can be adapted to avoid heating up the air around the passengers, but to still create a comfortable climate, thereby reducing the energy requirement of the heating system to an acceptable level given the limited battery capacity on board.

The heating system preferentially makes use of arrays of lasers. These lasers emit infrared light, which can be conveniently used to heat up the skin of a passenger. In this way heat losses of the passenger can directly be compensated, thus making the person feel comfortable although the compartment's temperature is low. Moreover, the energy can be directed to those body parts where the body's own generated heat is lost the fastest like the face, avoiding a decrease in local skin temperature. Another advantage of the heating system is that the radiative heat creates a comfortable situation instant on, which is especially important for the expected use of electric cars on short distances.

The heating system preferentially uses near infrared radiation provided by VCSELs. VCSELs offer a low cost and efficient source of near infrared laser radiation. Collimated output allows directionality and the small form factor enables integration in the car interior. The heating system preferentially provides a distributed VCSEL solution minimizing safety concerns and allowing an additional use of waste heat rather than requiring specific cooling.

The air temperature can be kept low without losing thermal comfort. For instance, at 300 W per person infrared heat, the air temperature may be 10 degrees lower than currently needed for feeling comfortable. The heating system is preferentially a personalized heating system, where the driver as well as the passenger can personally decide what level of heating they want and experience as comfortable. Thus, to different persons within the vehicle different lasers can be directed, which can be controlled independently from each other by the control unit such that each person can be heated as desired.

The near infrared light of the lasers has a relatively good penetration depth in skin. This has the advantage that the skin is heated in a larger layer, increasing the thermal comfort feeling and avoiding too high skin temperatures.

Several locations in the interior can be considered. In case of two front seats, a mounting of VCSEL arrays directly next to the front windshield is a preferred place. Here, a good opening angle towards the two front passengers is available, and additional heat generated by the lasers can be easily redirected to increase the temperature of the window slightly, thus avoiding condensation. Moreover, the VCSELs are preferentially distributed over a large area. First benefit is that no active cooling is needed as in a more concentrated laser system. Second advantage is that laser radiation coming not from a single opening but from many angles easily fulfils laser safety considerations. Preferred packages are long and flexible lines of many lasers as, for instance, also used for light emitting diodes.

Another preferred mounting position is close to the driver's feet. As these are normally at a well defined position it is easy to direct just a small amount of laser radiation to them. In addition the “frozen” position of the feet makes them especially sensitive to thermal discomfort increasing the value of the laser solution.

Since the heating system is very compact and can easily be integrated in various places, it is also very well suited in the aftermarket for instantaneous heating as provided by a pre-heating of cars.

The laser light is invisible to the human eye. Hence, the laser light is merely perceived as heat and does not disturb vision of the driver and passengers. The heating system described above with reference toFIGS. 1 and 2provides an advantageous combination with a camera system detecting the position of the passengers, which is an option for future cars also for improved safety. Near infrared light can be detected by standard CCD and CMOS cameras. In combination with a camera the near infrared light of the lasers can be made visible and switched on or off in case a person is sitting in front of the arrays. At the same time in the camera image most heat sensitive body parts can be recognized such as face, bare skin or hands. The light pattern of the lasers can be adjusted such that only these parts are heated. Since the heating system is preferentially instantaneous and lasers offer the unique possibility to change its light and thus heating pattern, the heating system is preferentially used to attract the driver's attention, in particular, depending on a dangerous situation detected by a driver assist system.

Although in the embodiment of the heating system described above with reference toFIGS. 1 and 2the heating system comprises a camera system and a driver assist system, in other embodiments the heating system may not comprise the camera system or the driver assist system. Moreover, the heating system may be adapted to cooperate with a separate camera system and/or a separate driver assist system, wherein the separate camera system is adapted to acquire an image of the living being and to send the acquired image to the heating system for allowing the control unit of the heating system to control the infrared laser system of the heating system depending on the acquired image and wherein the driver assist system is adapted to detect a dangerous situation, to generate an attention signal, if a dangerous situation has been detected, and to send the attention signal to the heating system, in order to allow the control unit of the heating system to control the infrared laser system of the heating system depending on the attention signal. In this case the image providing unit of the heating system can be a receiving unit for receiving the image from the camera system and for providing the received image to the control unit and the attention signal providing unit can be a receiving unit for receiving the attention signal from the driver assist system and for providing the received attention signal to the control unit of the heating system.

The control unit can be adapted to determine a spatially-dependent temperature value, wherein for different regions of the person visible in the image acquired by the camera system different temperature values can be determined. In this case, the control unit can be adapted to locally control the different lasers of the infrared laser system depending on—inter alia—the spatially-dependent temperature value.

Although inFIG. 1the first group5of infrared lasers is shown only above the windshield9, in other embodiments the first group5of infrared lasers can also be arranged at another location within the vehicle. Moreover, also additional groups of infrared lasers can be arranged within the vehicle. For instance, lines of infrared lasers can be arranged along the upper border, the lower border and/or the lateral borders of the windshield. Also the second group6of infrared lasers can be arranged at another location.

FIG. 4shows schematically and exemplarily a further embodiment of a heating system for heating a living being. In this embodiment, the heating system222is arranged above a display window223at or within an overhang225. However, in other embodiments the heating system can also be arranged at another location. The heating system222is adapted to heat a person202standing in front of the window display223. In a space226behind the window display223objects are located (not shown inFIG. 4) which are displayed. The heating system222comprises an infrared laser system205being controlled by a control unit213. Infrared laser light224emitted by the infrared laser system205is reflected by the person202, wherein the reflected light227is detected by a camera system207. Moreover, the ambient temperature is measured by a temperature sensor217. The control unit213receives the ambient temperature from the temperature sensor217and the image from the camera system207, in order to allow the control unit213to control the infrared laser system205depending on the ambient temperature and the acquired image.

The control of the infrared laser system205depending on the ambient temperature and the acquired image can be similar to the control of the heating system within the vehicle described above with reference toFIGS. 1 to 3. For instance, also the control unit213can be adapted to detect predefined regions on the person like the face or other bare skin regions from the acquired image and to control the infrared laser system205to provide the infrared laser light to the detected predefined regions. Alternatively or in addition, also the control unit213can be adapted to determine a temperature value being indicative of a temperature of the person202from the acquired image and to control the infrared laser system205depending on the determined temperature value.

The heating system can be integrated in or around the display window. When a person is detected standing in front of the window, for instance, by the camera system or another presence sensor, the infrared laser system can be switched on, by which heat is instantaneously sent towards the person in front of the window. The directionality of the laser beams can be adjusted by, for example, a lens system, a scanning minor system, or lasers spread around the window, and directed to heat up the body parts that are typically cold, for example, the face, the hands or any other uncovered body parts. In this way a thermal comfortable situation can be created instantaneously and flexibly. Thermal comfort is expected to be especially increased, since near-infrared radiation penetrates the skin. In this way too high skin temperatures are avoided, while heat loss is still compensated for.

In an embodiment, the heating system is adapted to increase the laser power to a higher level than required for a neutral, i.e. neither cold nor warm, thermal environment. The infrared laser system can also be combined with light emitting diodes for providing further directed illumination. By using the infrared laser system with increased laser power and optionally further direct illumination from light emitting diodes the thermal condition of being exposed to the sun on a sunny day can be mimicked. Direct sunlight with its directed radiation heat is by humans sensed as very pleasing. To mimic the thermal conditions of a sunny day (1000 W/m2), radiation with a power within a range of 10 to 20 W may be directed to the face of a person.

The heating system can also be adapted to be used in another environment. For instance the heating system can be integrated into a bus shelter. It is obviously not economical to provide a thermal neutral environment in a bus shelter by, for example, hot air. The bus shelter is very irregularly occupied in time and by design has an open structure for quick shelter and for people to feel safe. The laser heating system can be adapted to provide the heat instantaneous, avoiding heat up times of conventional heating methods, and to aim its heat directly and optionally only to the cold bodies.

The heating system can also be adapted to be used for, for instance, heating for outdoor sport bench, heating in outdoor areas assigned to smokers, personalized heating in an open fridge or freezer sections of a supermarket, heating person in ski lifts, heating in entrance regions of, for example, big stores et cetera. These situations are similar in that the occupation level is very dynamic, and by design an open, i.e. open to the outdoor, colder environment is required. Therefore heating by conventional means such as hot air is not economical due to the large heat losses to the environment.

It should be noted that the figures are only schematic figures, which are not to scale. For instance, the groups5,6of infrared lasers are, relative to the size of the vehicle, smaller than the corresponding boxes5,6shown inFIG. 1.

Although in the above described embodiments it is assumed that one or several persons are present, wherein the heating system is adapted to heat the one or several persons, in other embodiments the living being can also be an animal or a plant, which needs to be heated. Moreover, although in above described embodiments the vehicle is a car, in other embodiments the vehicle can also be another apparatus for incorporating and moving living beings like a bus, a truck, a ship, a plane, et cetera.

Operations like the determination whether a person is located in front of a laser array, the detection of predefined regions of the person, the determination of a temperature value based on an acquired image, et cetera performed by one or several units or devices can be performed by any other number of units or devices. For example, steps101and103can be performed by a single unit or by any other number of different units. The operations and/or the control of the heating system in accordance with the heating method can be implemented as program code means of a computer program and/or as dedicated hardware.