AN AIR GUIDING MEANS

Technical field

The present invention relates to an aerosol generating device of the nebuli zer type for producing inhalable droplets of a liquid on demand . More particularly, the present invention relates to such aerosol generating device including an air guiding means for allowing or promoting flow o f produced liquid droplets to a first vapour outlet and/or a second vapour outlet . The present invention also relates to a method of guiding air through such an aerosol generating device .

Technical Background

In the arts there are several types and concepts for aerosol generating devices or inhalation devices that serve a broad range of purposes including medical and therapeutic applications as well as non-medical devices such as electronic cigarettes , cigalikes , heat-not-burn devices , vapour inhalers and related devices . Existing aerosol generating devices either vapori ze a fluid before inhalation with by heating it to vapori zation temperature of the liquid at ambient pressure or deliver droplets of liquid at room temperature by, for example , employing an ultrasonic mesh .

Such aerosol generating devices or inhalation devices are oftentimes portable and handheld devices that can easily fit in the user' s hand or can be handled by the user' s fingers alone .

As noted above , some existing aerosol generating devices include a heater or ultrasonic mesh powered by an electrical power source and a liquid reservoir containing flavoured liquid that can be volati zed using the heater or ultrasonic mesh and trans ferred to a user of the aerosol generating device in an airflow, which is preferably guided through a mouthpiece of the device .

In case the aerosol is produced by using an ultrasonic mesh system, the aerosol is forcibly ej ected from the device , in particular into the mouth of the user, which is unlike typical electronic cigarettes where a liquid aerosol precursor is heated to vapori zation temperature to form the gaseous phase (vapour ) to be inhaled upon user' s inhalation to provide the needed airflow, which pulls the vapour into the mouth .

Aerosols generated by ultrasonic mesh systems usually comprise larger particle si ze than inhalable vapours generated by heating of aerosol precursors . Such larger particle si ze requires users to inhale sharply to ensure the aerosol penetrates suf ficiently deep into the lungs . Thi s leads to an increase of velocity of the vapour through the mouth of the user, hence , reduces the residence time in the mouth, which reduces and negatively impact the sensory experience of users , in particular the flavour perception and satis faction .

Summary of the invention

In view of the above , there is the desire to provide an aerosol generating device or inhalation device with at least one liquid j et device for producing droplets of a liquid on demand that is capable of increasing flavour satis faction of the user .

This aim may be achieved by an aerosol generating device as defined in claim 1 and a method of guiding air through such an aerosol generating device according to claim 15 . Embodiments of the inventive aerosol generating device and method may be found in the dependent claims , the following description and the accompanying drawings . In particular, in view of the l imitations discussed above , the present inventors have devised, in accordance with a first aspect herein, an aerosol generating device with at least one liquid j et device for producing droplets of a liquid on demand, comprising : an air conduit for delivering the produced liquid droplets to a first vapour outlet for inhalation by a user through the mouth and/or a second vapour outlet for inhalation by a user through the nose , and an air guiding means that is configured to allow or promote flow of the produced liquid droplets to the first vapour outlet and/or the second vapour outlet . The air guiding means is further configured to allow or promote flow of , in particular at least a maj ority of , the produced liquid droplets to the first vapour outlet when the user inhales through the mouth at the first vapour outlet and to allow or promote flow of , in particular at least a maj ority of , the produced liquid droplets to the second vapour outlet when the user does not inhale through the mouth at the first vapour outlet .

Hence , an aerosol generating device with at least one liquid j et device for producing droplets of a liquid on demand is provided, capable of increasing flavour satis faction of the user, in particular by generating aerosol after the user has finished puf fing ( inhaling through the mouth) and delivering the generated aerosol to the nose of the user . In other words , after the user has finished puf fing, the user inhales some of the generated aerosol through the nose which wil l deliver extra flavour . The air guiding means ensures that when the user inhales , the generated aerosol (vapour ) predominantly takes the first vapour outlet and when the user is not puf fing it takes the second vapour outlet .

In the context of the present invention, the term "maj ority" with regard to the promoted flow of produced liquid droplets is to be understood such that most of the generated liquid droplets either reaches or exits through the first vapour outlet or the second vapour outlet . In other words , at least 60% of the amount of generated liquid droplets or vapour , preferably at least 75% of the amount of generated liquid droplets or vapour and more preferably at least 90% of the amount of generated liquid droplets or vapour is promoted to flow to either one of the two vapour outlets .

Moreover, in the context of the present invention, the term "allow" with regard to the flow of the generated liquid droplets is to be understood such that by a change of the status of the air guiding means , for example a valve means is opened or closed, the generated liquid droplets are capable of reaching the desired vapour outlet and flow out of said vapour outlet . On the other hand, the term "promote" with regard to the flow of the generated liquid droplets is to be understood in the context of the present invention such that by a change of the status of the air guiding means , for example by closing at least partially a valve means , preferably completely closing said valve means , the generated liquid droplets are at least hindered to flow through this valve means and thereby forced to flow for example through a di f ferent ( opened) valve means . In this way, the flow path of the generated liquid droplets can be altered .

According to a further aspect of the present invention, the air conduit may comprise a first downstream portion leading to the first vapour outlet and a second downstream portion leading to the second vapour outlet .

Moreover, in some aspects of the present invention, the air guiding means may allow flow of the produced liquid droplets to the first vapour outlet by at least partially opening a valve means regulating the air flow through the first downstream portion and/or to the second vapour outlet by at least partially opening a valve means regulating the air flow through the second downstream portion . In some aspects of the present invention, the air guiding means may promote flow of the produced liquid droplets to the first vapour outlet by at least partially closing a valve means regulating the air flow through the second downstream portion and/or to the second vapour outlet by at least partially closing a valve means regulating the air flow through the first downstream portion .

According to a further aspect of the present invention, the air guiding means may promote f low of the produced liquid droplets to the first vapour outlet by guiding at least a maj ority, preferably all , of the produced liquid droplets to the first downstream portion and/or to the second vapour outlet by guiding at least a maj ority, preferably all , of the produced liquid droplets to the second downstream portion .

Furthermore , the air guiding means may be a throttle configured to close the first downstream portion when the user does not puf f and to at least partially open the first downstream portion when the user puf fs . The throttle may be at least partially opened by a suction force generated by the puf f of the user .

Moreover, the throttle may be at least partially of an elastic material , thereby enabling the throttle to be at least partially opened by the suction force of the puf f of the user .

According to a further aspect of the present invention, the first valve means and/or the second valve means and/or the throttle may be a SMA element ( s ) containing a shape memory alloy .

Moreover, the SMA element may contain a blend of 45Ni-50Ti- Furthermore , the liquid to be vapori zed to generate the liquid droplets (vapour ) may contain nicotine and/or flavours ( e . g . tobacco particles or extracts , mint , menthol , herbs , and/or fruit flavours ) . Optionally, the liquid may include additional substances , such as glycerin, propylene glycol and/or water, to aid formation of the liquid droplets or vapour or aerosol .

Furthermore , the aerosol generating device may include a control unit configured to control the air guiding means to allow or promote flow of the produced liquid droplets to the first vapour outlet and/or the second vapour outlet .

In addition, the control unit may further be configured to allow or promote flow of the produced liquid droplets to the first vapour outlet when a puf f sensor detects an inhalation (puf f ) of a user through the mouth at the first vapour outlet and to the second vapour outlet when the puf f sensor does not detect the inhalation (puf f ) of a user through the mouth at the first vapour outlet .

In some further aspects of the present invention, the aerosol generating device may additionally comprise at least one air inlet , wherein the at least one air inlet is preferably configured to guide or direct ambient air towards the at least one liquid j et device , in particular on a side of the at least one liquid j et device facing the first vapour outlet .

Moreover, at least part of the air conduit , preferably the whole conduit , may form a mixing chamber in which air from the at least one air inlet is mixed with the generated/produced liquid droplets .

According to a further aspect of the present invention, the at least one liquid j et device may be in the form of a vibrating mesh or a micro-electromechanical system, MEMS . Furthermore , at least one , preferably two , MEMS liquid j et device may be mounted on a printed circuit board, and ambient air may be guided through an opening of said printed circuit board .

The aerosol generating device may further comprise : a case , and a fluid chamber, wherein the case includes the first vapour outlet , the second vapour outlet and at least one air inlet and forms the air conduit .

Furthermore , the aerosol generating device may further comprise at least one heating element arranged to pre-heat ambient air, in particular air guided from the at least one air inlet toward the at least one liquid j et device , wherein the at least one heating element preferably comprises a ceramic heater housing .

The air conduit may include an upstream portion that tapers inwardly from the at least one liquid j et device and/or a downstream portion, in particular the first and/or second downstream portion, tapering inwardly from vapour outlet , in particular the first vapour outlet and/or the second vapour outlet .

The aerosol generating device may further comprise a control unit configured to control the delivery of the produced liquid droplets to the first vapour outlet for inhalation by a user though the mouth and/or the second vapour outlet for inhalation by a user through the nose , by controlling the air guiding means in such a manner that at least a maj ority o f the produced liquid droplets is allowed or promoted to flow to the first vapour outlet when the user puf fs and that at least a maj ority of the produced liquid droplets is allowed or promoted to flow to the second vapour outlet when the user does not puf f . Moreover, the aerosol generating device may further comprise a puf f sensor that is configured to detect whether a user is taking a puf f or not . Based on the detection of the puf f sensor, the control unit may be configured to determine whether the user is taking a puf f and accordingly control the delivery of the produced liquid droplets to the first vapour outlet and/or the second vapour outlet .

The puf f sensor or airflow detection means may be a pressure sensor configured to detect a pressure drop in the airflow through the device when a user takes a puf f . The pressure sensor may be in direct fluid communication with the air path through the device for directly detecting an airflow indicative of a user taking a puf f .

The present inventors have further devised, in accordance with a second aspect herein, a method of guiding air through an aerosol generating device , in particular an aerosol generating device such as described above . The method comprises the following steps :

- generation of droplets of a liquid on demand, in particular by at least one liquid j et device ,

- delivering the produced liquid droplets to a first vapour outlet for inhalation by a user through the mouth and/or a second vapour outlet for inhalation by a user through the nose , and

- allowing or promoting flow of the produced liquid droplets to the first vapour outlet and/or the second vapour outlet , wherein at least a maj ority of the produced liquid droplets is allowed or promoted to flow to the first vapour outlet when the user inhales through the mouth at the first vapour outlet and at least a maj ority of the produced liquid droplets is allowed or promoted to flow to the second vapour outlet when the user does not inhale through the mouth at the first vapour outlet . The method may further comprise a puf f detection step, in which an airflow through the device , in particular through the air conduit , is detected, in particular by a puf f sensor . The airflow through the device , in particular through the air conduit , is preferably determined by detecting a pressure drop in the device , in particular in the air conduit , when a user takes a puf f .

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings , in which :

Fig . 1 shows a schematic illustration of the general structure of an aerosol generation device in accordance with the present invention;

Fig . 2 shows a schematic view of a liquid j et device as employed in an aerosol generating device in accordance with an embodiment of the present invention;

Fig . 3 shows a schematic sectional view of the interior of an aerosol generating device according to a first embodiment of the present invention;

Fig . 4 shows a schematic sectional view of the interior of an aerosol generating device according to a second embodiment of the present invention; and

Fig . 5 shows a schematic sectional view of the interior of an aerosol generating device according to a third embodiment of the present invention . DETAILED DESCRIPTION

Embodiments of the present disclosure will now be explained with reference to the drawings . It will be apparent to those skilled in the field of aerosol generating devices from thi s disclosure that the following description of the embodiments is provided for illustration only and not for the purpose of limiting the disclosure as defined by the appended claims . Features of the embodiments described below can also be used to further characteri ze the device defined in the claims .

Modi fications of features can be combined to form further embodiments . Features described in individual embodiments can be provided in a single embodiment i f they are not incompatible . Likewise , features described in a single embodiment can be provided in several embodiments individually or in any suitable sub-combination . As used in the speci fication and the appended claims , the singular forms "a" , "an" , "the" and the like include plural referents unless the context clearly dictates otherwise .

The same reference numerals listed in di f ferent drawings refer to identical , corresponding or functionally similar elements . Moreover, where technical features in the drawings , detailed description or any claims are followed by reference signs , the reference signs have been included for the sole purpose of increasing the intelligibility of the drawings , detailed description, and claims . Accordingly, neither the reference signs nor their absence have any limiting ef fect on the scope of any claim elements .

As described hereinafter, example implementations of the present disclosure relate to an aerosol generating device or inhalation device . Electronic smoking devices or aerosol generating devices according to the present invention use electrical energy to generate an inhalable aerosol , in particular liquid droplets , (preferably without combusting the material to any signi ficant degree and/or without signi ficant chemical alteration of the material ) .

In some example implementations , electronic smoking devices or aerosol generating devices within the meaning of the present invention may transport the volatili zed particles in an airflow through the aerosol generating device to a user of the device , the user of the device being able to activate or deactivate the generation of aerosol and to control the duration, velocity and volume of the airflow by means of puf fing or inhaling action .

Figure 1 is a schematic illustration of an aerosol generating device 100 in accordance with the present invention . The aerosol generating device 100 comprises a liquid j et device 105 for producing droplets of a liquid on demand . The liquid j et device 105 comprises a fluid chamber, at least one ej ection noz zle , a supply channel and a heating element configured to heat the liquid in order to cause ej ection through the at least one ej ection noz zle .

The term fluid chamber is meant to cover j et technologies generally, including at least piezo j et and thermal j et devices , wherein in the latter case the fluid chamber is then usually referred to as a firing chamber .

The aerosol generating device 100 further comprises a control unit 160 in accordance with an embodiment herein . Operation of the control unit 160 will be described in more detail below in relation to Figures 2 to 5 .

More generally, the control unit 160 may, as in the present example embodiment , be configured to control operation of the aerosol generation device 100 . By way of example , in example embodiments such as the present example embodiment in which the aerosol generating device 100 comprises a power supply unit 170 , the control unit 160 may control charging of the power supply unit. Additionally or alternatively, the control unit 160 may optionally control supply of power to, and receive and process signals from any sensors or I/O units (e.g. optional button 165) included in the aerosol generating device 100 and control operation of the aerosol generating device 100 based on the received signals.

The control unit 160 may comprise one or more processing units or modules (e.g. a central processing unit (CPU) such as a microprocessor, or a suitably programmed field programmable gate array (FPGA) or application-specific integrated circuit (ASIC) ) . Additionally or alternatively, the control unit 160 may be provided with any memory sections (not shown) necessary to perform its function of controlling operation of the aerosol generating device 100. Such memory sections may be provided as part of (comprised in) the control unit 160 (e.g. integrally formed or provided on the same chip) or provided separately, but electrically connected to the control unit 160. By way of example, the memory sections may comprise both volatile and non-volatile memory resources, including, for example, a working memory (e.g. a random access memory) . In addition, the memory sections may include an instruction store (e.g. a ROM in the form of an electrically-erasable programmable read-only memory (EEPROM) or flash memory) storing a computer program comprising computer-readable instructions which, when executed by the control unit 160, cause the control unit 160 to perform various functions described herein.

The computer program comprising the computer-readable instructions which, when executed by the control unit 160, cause the control unit 160 to perform various functions described herein may, for example, be a software or a firmware program.

The aerosol generating device 100 may, as in the present example embodiment, further comprise a power supply unit 170. The power supply unit 170 may, as in the present example embodiment , be a rechargeable power supply . The power supply unit 170 may, as in the present example embodiment , be a lithium-ion battery . Alternatively, the power supply unit 170 may be , for example , a chargeable secondary battery or an electric double layer capacitor (EDLC ) or any other suitable power supply means known in the art .

Additionally or alternatively, the aerosol generating device 100 may, as in the present example embodiment , comprise a reservoir 180 for storing an amount of said liquid to be vapori zed . By way of non-limiting example , the liquid may contain nicotine and/or flavours ( e . g . mint , menthol , herbs , tobacco particles , tobacco extract and/or fruit flavours ) . Optionally, the liquid stored in the reservoir 180 may include additional substances , such as glycerin, propylene glycol and/or water, to aid formation of an aerosol .

By way of example , the reservoir 180 and/or the liquid stored therein may be replaceable . By way of example , at least the reservoir 180 of the aerosol generating device 100 may be provided in the form of a replaceable cartridge .

Preferably, the aerosol generating device 100 may further comprise a reservoir heating element (not shown) arranged to heat the liquid in said reservoir 180 and/or in a flow path between said reservoir 180 and liquid j et device 105 to a predetermined liquid reservoir temperature . This may allow the liquid to be provided to the liquid j et device 105 from the reservoir 180 at an optimal temperature for producing droplets by the liquid j et device 105 .

Additionally or alternatively, the aerosol generating device 100 may, as the present example embodiment , comprise an air inlet 150 and a mixing chamber (not shown) in which air from said air inlet 130 is mixed with the liquid droplets generated by the liquid jet device 105. The air inlet 150 may further comprise at least one air inlet orifice 155 at some suitable site of said aerosol generating device 100.

Additionally or alternatively, the aerosol generating device 100 may, as in the present example embodiment, comprise a mouthpiece opening 310 (first vapour outlet 120) through which a user may inhale the inhalation vapour. The mouthpiece 300 may be integral with the housing of the aerosol generating device 100, it may be replaceable, or may form part of a capsule or cartridge. The latter may comprise further elements, such as the mixing chamber, the liquid jet device 105 or the reservoir 170 so as to provide a replaceability of further elements for achieving convenience, flexibility, reliability and/or safety. Here, any combination of elements is feasible.

Figure 2 is a schematic view of a liquid jet device 105 as employed in an aerosol generating device in accordance with an embodiment of the present invention.

The liquid jet device 105 comprises a fluid chamber 211, at least one ejection nozzle 214, a supply channel 213 and a heating element 212 configured to heat the liquid 216 in order to cause ejection through the at least one ejection nozzle 214.

The heating element 212 may, as in the present example embodiment, be arranged in the vicinity of the fluid chamber 211. In such embodiments, the control unit 160 may control the heating element 212 to heat up a portion of the liquid 216 to vaporized and form a gas bubble 217. The resulting expansion leads to the ejection of an amount of the liquid 216 in the form of a drop or droplet 215 through the ejection nozzle 214. By way of example, the drop 215 may then form a vapour or aerosol in the mixing chamber. By way of example, the fluid chamber 211 may, as in the present example embodiment, be in liquid communication with the reservoir 170 for providing liquid 216 to the fluid chamber 211 so as to be vaporized or atomized.

The heating element 212 may, for example, be a resistive heating element. By way of more specific example, the heating element 212 may be a resistor embedded in the substrate .

The liquid jet device 105 may, as in the present example embodiment, be formed as a micro-electromechanical system, MEMS, in a substrate of any suitable material, for example silicon. In such example embodiments, the fluid chamber 211, the ejection nozzle 214, and the supply channel 213 may be formed on the substrate. In addition, in a case where the heating element 212 comprises a resistor, the resistor may be deposited on a substrate of the MEMs . Such a MEMs liquid jet device may, by way of non-limiting example, be mounted on a printed circuit board.

In the liquid jet device 105 showing in Figure 2, the liquid jet device 105 comprises a single ejection nozzle 214 in association with the heating element 212. Alternatively, the liquid jet device may comprise two or more ejection nozzles in association with the heating element 212. That is, the liquid jet device 105 may have a 'shower head' type design in which there are multiple ejection nozzles per heating element .

Figure 3 is a schematic sectional view of the interior of an aerosol generating device 100 according to a first embodiment of the present invention. The aerosol generating device 100 according to the present embodiment comprises a case 101 and a fluid chamber 102 (reservoir 180) , wherein the case 101 includes a first vapour outlet 120 and a second vapour outlet 130. By way of example , the case 101 may, as in the present example embodiment , comprise two air inlets 150 and form an air conduit 110 between the two air inlets 150 and the first vapour outlet 120 and the second vapour outlet 130 . Moreover, the shown aerosol generating device 100 comprises one liquid j et device 105 for producing droplets of the liquid stored in the fluid chamber 102 when activated . The first vapour outlet 120 is preferably arranged in the mouthpiece 300 (not shown) , particularly at the position of the mouthpiece opening 310 (not shown) so that a user can inhale through the mouthpiece opening 310 when taking a puf f . Furthermore , the second vapour outlet 130 is preferably also arranged in the mouthpiece 300 (not shown) , particularly at a position where the user can inhale the generated vapour or droplets through the nose when not taking a puf f , but still having the device in his/her mouth . By way of example , the aerosol generating device 100 , in particular the mouthpiece 300 (not shown) , may, as in the present example embodiment , comprise two second vapour outlets 160 , which are positioned on an outer circumferential surface of the aerosol generating device 100 , in particular the mouthpiece 300 (not shown) , radially apart from each other .

The shown aerosol generating device 100 further comprises an air guiding means 140 that allows or promotes flow of the produced liquid droplets (vapour ) to the first vapour outlet 120 when the user takes a puf f and allows or promotes flow of the produced liquid droplets (vapour ) to the two second vapour outlets 130 when the user does not puf f . Therefore , the air conduit 110 firstly comprises a first downstream portion 110A leading to the first vapour outlet 120 and two second downstream portions H OB leading to the second vapour outlet 130 . In other words , the first downstream portion 110A is arranged at an end of the air conduit 110 facing the mouth of the user when the device is inserted in the mouth, and the two second downstream portions H OB are arranged between the two second vapour outlets 130 and the liquid j et device 105 . Accordingly, the first downstream portion 110A is arranged more downstream than the two second downstream portions H OB .

By way of example , the air guiding means 140 may, as in the present example embodiment , comprise a first valve means 140A regulating the air flow through the first downstream portion 110A. Here , by at least partially opening the first valve means 140A, flow of the produced liquid droplets through the first downstream portion 110A and thereby through the first vapour outlet 120 is allowed, enabling the user to take a puf f through the mouthpiece opening 310 (not shown) .

The first valve means 140A in the present example embodiment may be a SMA element or at least partially contain a SMA element containing a shape memory alloy, wherein the SMA element preferably contains a blend of 45Ni-50Ti-5Cu . Thus , by changing the temperature of the SMA element , for example by a heating element such as a resistance heater, the first valve means 140A can be opened and closed .

In detail , the SMA element may be configured to close a through hole of the first valve means 140A by taking a first shape during normal conditions ( e . g . , at room temperature ) and to at least partially open the through hole of the first valve means 140A by taking a second shape when the temperature exceeds a predetermined threshold value ( e . g . , above 70 ° C ) . Moreover, the SMA element may be configured to take back its first shape when the temperature falls below the predetermined threshold value so as to close , in particularly completely close , the through hole of the first valve means 140A.

In this regard it is further preferred that the SMA element may have a reaction time of less than 100ms to fully open . A short reaction time of the valve means increases ef ficiency of the flavour enhancement through the second vapour outlet ( s ) 130 while ensuring a smooth smoking experience of the user .

Additionally or alternatively, the first valve means 140A may be surrounded by an elastic seal , preferably made of silicon . Such an elastic seal helps to avoid the intrusion of dust or humidity into the housing in the closed state of the valve means and can be elastically deformed by the valve mans in case the valve means is opened .

The SMA element of the first valve means 140A can further have a circular or semi-circular shape and be placed onto the elastic seal to open up or straighten partially, thereby increasing the diameter of its circular or semi-circular shape , pushing the elastic seal radially apart and increasing the diameter of the through hole or valve opening of the first valve means 140A.

By way of example , when energi zing the heating element (not shown) , the temperature of the SMA element increases above the predetermined threshold value , thereby opening the first valve means 140A enabling the user to take a puf f . On the other hand, when stopping energi zing of the heating element (not shown) , the temperature of the SMA element will drop below the predetermined threshold value , thereby closing the first valve means 140A. By closing the first valve means 140A, the liquid droplets produced by the liquid j et device 105 will be forced to exit the aerosol generating device , in particular the mouthpiece 300 (not shown) through the two second vapour outlets 130 . Thereby, it will be ensured that when the user stops puf fing and the first valve means 140A is closed that the generated vapour exits through the second vapour outlets 130 which are arranged at a position close to the nose of the user, thereby enabling the user to inhale the generated vapour through the nose while not taking a puf f , which leads to an increased flavour satis faction of the user . Additionally or alternatively, the air guiding means 140 may, as in the present example embodiment , comprise two second valve means 140B regulating the air flow through the two second downstream portions H OB . Here , by at least partially opening the second valve means 140B, flow of the produced liquid droplets through the second downstream portions H OB and thereby trough the two second vapour outlets 130 is allowed, enabling the user to inhale the generated vapour through the nose while not taking a puf f . The second valve means 140B in the present example embodiment may also be a SMA element or at least partially contain a SMA element , as explained in more detail above with respect to the first valve means 140A.

Yet , since the suction force of the user during a puf f is suf ficient to ensure that at least most of the generated liquid droplets or vapour exits the device through the first vapour outlet towards the mouth of the user, the second valve means 140A may control the flow of air through the second downstream portions H OB in an upstream direction ( inflow direction) rather than in a downstream direction ( outflow direction) . In other words , the second valve means 140A may be check valves that allow the generated vapour to exit the device but prevent ambient air from entering the device . Thereby, it can be ensured that ambient air only enters the device , in particular the mixing chamber, via the dedicated air inlet ( s ) 150 , while the user is taking a puf f . In this way, it can be ensured that the generated vapour is not diluted by mixing with false air .

Figure 4 shows a schematic sectional view of the interior of an aerosol generating device 100 according to a second embodiment of the present invention . The shown aerosol generating device 100 has the same general structure as the aerosol generating device 100 according to the first embodiment of the present invention, hence , a detailed description of said general structure will be omitted here . The air guiding means 140 according to the present embodiment comprises a throttle 140C that is arranged in the first downstream portion 110A and configured to close said downstream portion 110A when the user does not take a puf f . On the other hand, when the user takes a puf f , the throttle will be at least partially opened by a suction force generated by the puf f of the user . In this way, the structure of the air guiding means and in particular the control of the air guiding means can be simpli fied, as the throttle 140C automatically opens when the user takes a puf f and closes when the user stops taking a puf f . Thus , when the user stops taking a puf f and the throttle 140C closes , the generated vapour is forced to exit the device through the second vapour outlets 130 .

Yet , as mentioned above with respect to the first embodiment , the suction force of the user during a puf f is suf ficient to ensure that at least most of the generated liquid droplets or vapour exits the device through the first vapour outlet towards the mouth of the user . Thus , valve means or throttle ( s ) need not necessarily be provided for the second downstream portion ( s ) H OB to control the air flow through those downstream portion ( s ) . However, in order to avoid that the generated vapour is diluted by mixing with false air, in particular ambient air entering through the second vapour outlets 130 , check valves may be provided for the second downstream portions H OB that are configured to allow the generated vapour to exit the device through the second vapour outlets 130 but prevent ambient air from entering the device . Thereby, it can be ensured that ambient air only enters the device , in particular the mixing chamber, via the dedicated air inlet ( s ) 150 , while the user is taking a puf f .

Figure 5 shows a schematic sectional view of the interior of an aerosol generating device 100 according to a third embodiment of the present invention . The shown aerosol generating device 100 has the same general structure as the aerosol generating device 100 according to the first embodiment of the present invention, hence , a detailed description of said general structure will be omitted here . The air guiding means 140 according to the present embodiment contrary to the first two embodiments described above does not comprise any closing means (valve means or throttle ) for controlling the air flow through one of the downstream portions 110A, H OB, but instead comprises a guiding element 140D that is configured to promote flow of the produced liquid droplets to the first vapour outlet 120 by guiding at least a maj ority, preferably all , of the produced liquid droplets to the first downstream portion 110A when the user takes a puf f and to promote flow of the produced liquid droplets to the second vapour outlet 130 by guiding at least a maj ority, preferably all , of the produced liquid droplets to the second downstream portion H OB when the user takes no puf f .

Here , the air guiding element 140 may be an elastic element configured to be elastically deformed by the suction force of the puf f so that an air channel to the first vapour outlet 120 is opened and the generated vapour is guided to the first vapour outlet 120 . As soon as no more suction force is applied to the elastic element , it assumes its original shape , closing the air channel to the first vapour outlet 120 and guiding the generated vapour to the second vapour outlet ( s ) 130 . Additionally or alternatively, the air guiding element 140D may be a rigid element such as a plastic lever driven by an actuator such as a piezoelectric element . Although combinations of an elastic element or an elastic portion with a rigid element driven by an actuator such as a piezoelectric element are conceivable .

As shown in Figures 3 to 5 , in all embodiments of the present invention, the aerosol generating device 100 may further comprise at least one air inlet 150 , in the example embodiments 1 to 3 two air inlets 150 , wherein the air inlet ( s ) 150 is configured to guide or direct ambient air towards the at least one liquid j et device 105 , in particular on a side of the at least one liquid j et device 105 facing the first vapour outlet 120 . Moreover, in the shown embodiments at least part of the air conduit 110 may form a mixing chamber in which air from the at least one air inlet 150 is mixed with the generated or produced liquid droplets .

By way of example , the shown liquid j et device 105 may be in the form of a vibrating mesh or a micro-electromechanical system, MEMS . Here , in case of micro-electromechanical systems , preferably two MEMS l iquid j et devices may be mounted on a printed circuit board, wherein ambient air is guided through an opening of said printed circuit board to produce liquid droplets .

Additionally or alternatively, the air conduit 110 may, as shown in the example embodiments 1 to 3 , include an upstream portion that tapers inwardly from the at least one liquid j et device 105 and/or a downstream portion, in particular the first and/or second downstream portion ( s ) 110A, H OB, may taper inwardly from the vapour outlet , in particular the first vapour outlet 120 and/or the second vapour outlet 130 .

Furthermore , as indicated above , the aerosol generating device 100 according to the present invention may comprise a control unit 160 configured to control the air guiding means 140 to allow or promote f low of the produced liquid droplets to the first vapour outlet 120 and/or the second vapour outlet 130 . Here , the control unit 160 may in particular be configured to allow or promote flow of the produced liquid droplets to the f irst vapour outlet 120 when a puf f sensor detects the puf f of a user and to the second vapour outlet 130 when the puf f sensor does not detect the puf f of a user . In more detail , the control unit 160 may control the air guiding means in such a manner that at least a maj ority, in particular all , of the produced liquid droplets is allowed or promoted to flow to the first vapour outlet when the user puf fs and that at least a maj ority, in particular all , of the produced liquid droplets is allowed or promoted to flow to the second vapour outlet when the user does not puf f .

By way of example , in case of the first embodiment described above with respect to Fig . 3 , the control unit 160 may control the first valve means 140A to open, at least partially, and to close the second valve means 140B, when the control unit determines that a user is taking a puf f . In this way, the generated vapour or liquid droplets can exit the device through the first vapour outlet 120 , but not through the second vapour outlet ( s ) 130 . Hence , the user is capable of inhaling the generated vapour or liquid droplets in the usual manner without being disturbed by vapour exiting the second vapour outlet ( s ) 130 close to the nose . On the other hand, when the control unit 160 determines that the user stops taking a puf f or does not take a puf f , the control unit 160 may control the first valve means 140A to close , at least partially, and to open the second valve means 140B . In this way, the generated vapour or liquid droplets cannot exit the device through the first vapour outlet 120 , but through the second vapour outlet ( s ) 130 . Thereby, enabling the user to inhale the generated vapour or liquid droplets through the nose when not puf fing, hence, increasing the flavour satis faction of the user as the residence time for the vapour components in the mouth of the user can be increased .

In addition, the aerosol generating device may comprise a puf f sensor (not shown) . According to one embodiment of the present invention, the puf f sensor may be a pressure sensor that is in direct fluid communication with the air path through the device , preferably arranged at a position of the air path that is in direct fluid communication with the first vapour outlet 130 . In this way, the pressure sensor is capable of directly detecting an airflow indicative of a user taking a puf f . Based on the detection of the puf f sensor , the control unit 160 may be configured to determine whether the user is taking a puf f or not .

Although detailed embodiments have been described, they only serve to provide a better understanding of the invention defined by the independent claims , and are not to be seen as limiting .

REFERENCE LIST

100 Aerosol generating device 101 Case 102 Fluid chamber 105 Liquid j et device 110 Air conduit 110A First downstream portion H OB Second downstream portion 120 First vapour outlet

130 Second vapour outlet 140 Air guiding means

140A First valve means 140B Second Valve means 140C Throttle 140D Air guiding element 150 Air inlet 160 Control unit 170 Power supply unit 180 Reservoir ( fluid chamber 102 )

211 Fluid chamber ( of the liquid j et device )

212 Heating element ( of the liquid j et device ) 213 Supply channel 214 Ej ection noz zle 215 Liquid drop (vapour ) Liquid Gas bubble Mouthpiece Mouthpiece opening (first vapour outlet 120)