Patent Description:
In the recent years devices which heat rather than burn or cause combustion of a substance to generate a vapour or aerosol for inhalation by a user have become increasingly popular.

Such commonly used device which heat rather than burn or cause a combustion of a substance may be tobacco-based device also known as heated tobacco products. These devices normally contain tobacco and/or other suitable substance that is heated but not burned to create an inhalable aerosol. The tobacco and/or the other suitable substance may in general also be called an aerosol generating substance and the device in general may be called an aerosol generating device. As an example; document <CIT> discloses a device which is capable of indicating the battery level or the amount of consumable left.

Normally, the aerosol generating substance is placed in a container, also called a stick or a tobacco stick, that can be inserted in and removed from the aerosol generating device by the user. Therefore, the stick or the tobacco stick is a consumable article.

For heating the aerosol generating substance the aerosol generating device comprises a battery for providing power to the heating arrangement of the aerosol generating device that heats the aerosol generating substance. The amount of charge that is stored in the battery when the battery is fully charged normally allows that more than one consumable article is fully used. Fully used is to be understood in the sense that the aerosol generating substance for producing an aerosol has been burned. The battery is normally a rechargeable battery.

Usually, the user checks the amount of charge remaining in the battery (also called here below battery level) before starting an aerosol generating session with the aerosol generating device for ensuring whether a consumable article that is inserted or is to be inserted in the aerosol generating device can be fully used with the amount of charge remaining in the battery. This is particularly important for the user if the user intends to go to an environment in which it is not possible, or it is difficult to charge the battery.

In the conventional art, the battery level is indicated in percentage using any suitable output means placed on the aerosol generating device. The percentage indicates the battery level with respect to a fully charged battery or entirely emptied battery. However, based merely on indication of the percentage it is difficult for the user to comprehend how many consumable articles can be fully used with the amount of charge remaining in the battery.

On the other hand, the number of consumable articles that can be fully used with the amount of charge remaining in the battery is an important information for the user which enables the user to better manage the charging of the battery. For example, the user may plan in advance the charging of the battery so that unnecessary charging and discharging, for example complete discharging of the battery that may negatively or disadvantageously influence the lifetime and performance of the battery may be effectively avoided. In addition, it is also preferred that the consumable articles are fully used which avoids a waste of resources for producing the consumable articles. Further, this information also enables the user to better manage its own consumption of consumable articles thus reducing its own anxiety regarding the amount of charge remaining in the battery. For example, the user may like to know whether there is enough amount of charge remaining in the battery for the user to fully empty the next, for example, three or other desired number of consumable articles.

Moreover, indicating the battery level is also dependent on the overall shape and design of the aerosol generating device. For example, since the aerosol generating device is a handheld device, normally a smooth surface that provides physical ergonomic advantage for the user is preferred. Such smooth surface should not be interrupted by means for indicating the battery level.

Therefore, there is a need for an indication of a battery level of a battery of an aerosol generating device that is easily understandable for the user and can enable better management of the charging of the battery by the user as well as the user's own consumption of consumable articles. Even further such indication of battery level should also be in accordance with the overall shape and design of the aerosol generating device.

The mentioned problems and objects are met by the subject-matter of the independent claims.

According to one aspect of the present invention, as defined in claim <NUM>, there is provided a method of indicating a battery level of a battery of an aerosol generating device for generating an aerosol from an aerosol generating substance contained in a consumable article, the method comprising the steps of: determining the amount of charge remaining in the battery; calculating the number of consumable articles that can be fully used with the determined amount of charge remaining in the battery; and displaying an information, said information indicating the calculated number of consumable articles that can be fully used with the determined amount of charge remaining in the battery.

According to another aspect of the present invention, as defined in claim <NUM>, there is provided an aerosol generating device comprising a heating chamber configured so that a user can place a consumable article containing an aerosol generating substance into said heating chamber; a heater configured to supply heat to the heating chamber to thereby heat the aerosol generating substance in the consumable article; a battery configured to supply electrical power to the heater; an output unit for displaying an information to the user; and a control unit configured to carry out the method according to the above elaborated aspect.

According to another aspect of the present invention, as defined in claim <NUM>, there is provided a system comprising the aerosol generating device according to the above-elaborated aspect and a charging case, said charging case comprising a display for displaying said calculated number.

Embodiments of the present invention which are presented for better understanding the inventive concept of the present invention, but which are not to be seen as limiting the present invention, will now be described with reference to the figures in which:.

<FIG> shows a schematic view of the aerosol generating device <NUM> according to the embodiment of the present invention.

The aerosol generating device <NUM> according to the embodiment of the present invention is a handheld device with a pebble-like shape and comprises an access portion <NUM> and a housing portion <NUM>. The access portion <NUM> is in the top part of the aerosol generating device <NUM> and comprises means for opening and closing an opening <NUM> to a heating chamber of the aerosol generating device <NUM>. In the heating chamber, a user may place at least one consumable article <NUM> comprising an aerosol generating substance. The access portion <NUM> may comprise for example a lid that can at least partly be removed from the housing portion <NUM>. In other embodiment the access portion <NUM> may comprise for example a slider. The slider may be moved between two positions such as opened position and closed position for opening and closing the opening <NUM> to the heating chamber.

<FIG> shows a schematic view of the aerosol generating device <NUM> according to the embodiment of the present invention when the access portion <NUM> is closed. As further shown in <FIG> the aerosol generating device <NUM> may comprise on the outer side of the housing portion <NUM> one or more input means <NUM> (comprising for example one or more buttons) for controlling, for example turning on or off, the aerosol generating device <NUM>.

The housing portion <NUM> of the aerosol generating device <NUM> may have a smooth outer surface which together with the pebble-like shape provides a physical ergonomic advantage for the user. The housing portion <NUM> houses at least the mentioned heating chamber and houses further components of the aerosol generating device <NUM> as elaborated below.

The user can place a consumable article <NUM> containing an aerosol generating substance into the heating chamber.

<FIG> shows schematic view of the consumable article <NUM> according to the embodiment of the present invention. The consumable article <NUM> may be a stick or a tobacco stick comprising tobacco and/or other suitable substance that is heated but not burned in the heating chamber to create an inhalable aerosol. The consumable article <NUM> may further comprise a flavour adding substance. The consumable article <NUM> may have an elongated form, for example a cylindrical form as shown in <FIG>. The consumable article <NUM> may be partitioned in two parts: in the first part <NUM> the aerosol generating substance is placed while the second part is a filter portion <NUM>.

<FIG> shows a schematic view of the functional components of the aerosol generating device <NUM> of the embodiment of the present invention.

The heating chamber <NUM> mentioned above may be such that the user can place one consumable article <NUM> at a time or the user may place more than one consumable articles <NUM> at a time. The heating chamber <NUM> may also have a cylindrical form as the consumable article <NUM>. The form of the consumable article <NUM> and the heating chamber <NUM> are not to be seen as limiting to the concept of the present invention.

The aerosol generating device <NUM> comprises further a heater <NUM> (or a heating arrangement <NUM>) for supplying heat to the heating chamber <NUM> to thereby heat the aerosol generating substance <NUM> in the consumable article <NUM>. The heater <NUM> may be a heater <NUM> that supplies heat to the heating chamber <NUM> based on a resistive heating, but may also be a heater <NUM> that supplies heat to the heating chamber <NUM> based on inductive heating. The type of heating is not be seen as limiting to the concept of the present invention.

Further, the heater <NUM> may be placed outside the heating chamber <NUM> so that it indirectly, for example through convective heat transfer, heats the aerosol generating substance <NUM> but may also be placed entirely or at least partially in the heating chamber <NUM> and directly or indirectly heat the aerosol generating substance <NUM>. The position of the heater <NUM> with respect to the heating chamber <NUM> is not to be seen as limiting to the concept of the present invention.

The aerosol generating device <NUM> comprises further a battery <NUM> for supplying electrical power to the heater <NUM>. The battery <NUM> is a rechargeable battery. When the battery <NUM> is fully charged the amount of charge stored in the battery enables that more than one consumable article <NUM> is fully used (or consumed). Fully used (or consumed) is to be understood in the sense that the aerosol generating substance <NUM> for producing an aerosol has burned out. In the following, the full use (or consumption) of one consumable article <NUM> may also be called a complete (or completed) aerosol generating session.

The aerosol generating device <NUM> comprises further an output unit <NUM> for displaying an information to the user. The information comprises an information for indicating an amount of charge remaining in the battery <NUM> (also called here below battery level). The output unit <NUM> may be any suitable output unit, for example a liquid crystal display (LCD display) or LED display, or one or more indicators, for example lamps or light emitting devices (LEDs). The lamps or light emitting devices (LEDs) may be single coloured or multi coloured, or in other words may emit single colour light or may be able to emit light in more than one colour or may emit white colour light. Details of the output unit <NUM> will be elaborated further below.

The aerosol generating device <NUM> comprises further a control unit <NUM> for carrying out various processing as will be elaborated further below. In particular, the control unit <NUM> carries our processing for performing the steps of the method for indicating the battery level of the battery <NUM> of the aerosol generating device <NUM> elaborated further below.

The control unit <NUM> is any suitable unit or comprises any suitable unit such as computer processing unit that can perform computer processing. The control unit <NUM> (also called controller) may be for example a micro processing unit (MCU). Further, the control unit <NUM> may comprise storage means, such as a memory. The memory may also be a separate unit from the control unit <NUM> also placed inside the housing portion <NUM>. The memory may store different information needed for the processing by the control unit <NUM>. Further, the memory may store computer program (code) comprising instructions which, when the program is executed by the control unit <NUM>, cause the control unit <NUM> to carry out the processing (or method steps) of the embodiment of the present invention as will be elaborated further below.

The aerosol generating device <NUM> may also comprise transmitting and/or receiving means <NUM> for transmitting and/or receiving data to/from an external device. The external device may be an electronic device such as a smartphone <NUM> or other electronic device for personal use or may be a charging case <NUM>. The charging case <NUM> may be used for charging the battery <NUM> of the aerosol generating device <NUM> when the aerosol generating device <NUM> is placed in the charging case <NUM>. <FIG> shows schematically the aerosol generating device <NUM> communicating with a smartphone <NUM> and a charging case <NUM>.

<FIG> shows a flow diagram of the method of indicating the battery level of the battery <NUM> of the aerosol generating device <NUM> for generating an aerosol from the aerosol generating substance contained in the consumable article <NUM> according to the embodiment of the present invention.

The method comprises the following steps: determining the amount of charge remaining in the battery <NUM> (step S <NUM>); calculating the number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM> (step S <NUM>); and displaying an information, said information indicating the calculated number of consumable articles that can be fully used with the determined amount of charge remaining in the battery <NUM> (S <NUM>).

In the following, further details of these steps are elaborated.

In the embodiments of the present invention the control unit <NUM> may determine the amount of charge remaining in the battery <NUM> based on different measurements. The particular manner of determining the amount of charge remaining in the battery <NUM> is not to be seen as limiting to the present invention.

The calculation of the number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM> can be performed in an initial calibration process or in a learning process as elaborated further below.

The initial calibration process relates to the initial use of the aerosol generating device <NUM>. The initial use may be understood in the sense of the user intends to start a first aerosol generating session.

In the memory of the aerosol generating device <NUM> an initial information comprising a pre-determined amount (Z0) of charge to fully use one consumable article <NUM> is stored. This pre-determined amount of charge (Z0) to fully use one consumable article <NUM> may be obtained in laboratory settings during tests performed on the aerosol generating device <NUM> or other aerosol generating device comprising a battery with the same or similar characteristics as the aerosol generating device <NUM> of the present embodiment and/or one consumable article or may be obtained by way of theoretical calculations. This information may than be pre-stored in the aerosol generating device <NUM> as the pre-determined amount (Z0) of charge to fully use one consumable article <NUM>. Pre-stored means that when the user purchases the aerosol generating device <NUM> this information is stored in the memory of the aerosol generating device <NUM>.

For the initial calibration the control unit <NUM> determines the amount of charge remaining in the battery <NUM> and calculates the number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM> based on the pre-stored amount of charge (Z0) to use one consumable article <NUM> and the determined amount of charge remaining in the battery <NUM>. The control unit <NUM> then carries out the step of displaying information indicating the calculated number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM>. The control unit <NUM> carrying out the step of displaying information indicating the calculated number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM> may involve the control unit <NUM> sending an instruction to the output unit <NUM> to display the information indicating the calculated number. The information indicating the calculated number may be displayed to the user through numerical representation or a visual or graphical representation as elaborated further below.

As the user uses the aerosol generating device <NUM>, the control unit <NUM> calculates the number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM> in the learning process as elaborated below. The learning process is advantageous since with the progress of use of the aerosol generating device <NUM> the battery <NUM> may degrade, such that the above-elaborated pre-stored amount of charge (Z0) to use one consumable article <NUM> may not correspond to the amount of charge to use one consumable article <NUM> with the current battery characteristics.

The control unit <NUM> determines a first value (Y) for the amount of charge remaining in the battery <NUM> before a consumable article <NUM> is used. The first value (Y) may be determined, for example, at the start of supplying electrical power for using the consumable article or a predetermined time period before the start of supplying electrical power for using the consumable article or based on a pre-determined triggering signal received by the control unit <NUM>. Examples of such triggering signal are described further below.

The control unit <NUM> determines further a second value (X) for the amount of charge remaining in the battery <NUM> after the consumable article <NUM> is fully used.

The second value (X) is subtracted from the first value (Y) and an amount (Z1) of charge needed to fully use one consumable article <NUM> as the result of subtracting the second value (X) from the first value (Y) is determined. This determined amount (Z1) of charge needed to fully use one consumable article <NUM> is stored. The control unit <NUM> may store the determined amount (Z1) in the memory described above.

The control unit <NUM> carries out the step of determining the amount of charge needed to fully use one consumable article <NUM> for the next consumptions, or in other words, each next time one consumable article <NUM> is fully used, the amount of charge needed to fully use the consumable article <NUM> is determined as elaborated above such that data Z2, Z3,. Zx are generated and stored in the memory described above.

The step of calculating the number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM> may be carried out in different ways elaborated here below.

In one embodiment of the present invention the first value (Y) for the amount of charge remaining in the battery <NUM> before the consumable article <NUM> is used is divided with the last stored amount (Zx) of charge needed to fully use one consumable article (last consumption) to thereby obtain a first division result. The first division result may be rounded down to the nearest whole number to thereby calculate the number of consumable articles <NUM> that can be fully used to generate the aerosol with the charge remaining in the battery <NUM>.

In other embodiment of the present invention an average value of the amount (Zav) of charge needed to fully use one consumable article <NUM> may be calculated, and the first value (Y) for the amount of charge remaining in the battery <NUM> before the consumable article <NUM> is used is divided with said average value of the amount (Zav) of charge needed to fully use one consumable article <NUM> to thereby obtain a second division result. The second division result may be rounded down to the nearest whole number to thereby calculate the number of consumable articles <NUM> that can be fully used to generate aerosol with the charge remaining in the battery <NUM>.

In one embodiment of the present invention the average value of the amount (Zav) of charge needed to fully use one consumable is calculated from a predetermined number x of subsequently stored amounts (Zi,. ,Zi+x) (last x consumptions) of charge needed to fully use one consumable.

Further, in other embodiment of the present invention the average value of the amount (Zav) of charge needed to fully use one consumable article involves determining a time period based on a clock signal, and calculating the average value of the amount (Zav) of charge needed to fully use one consumable from the stored amounts (Zi,. ,Zi+x) of charge needed to fully use one consumable article, stored within the determined time period. The length of the time-period may also be pre-stored in the memory elaborated above. For example, if the control unit <NUM> has an internal clock the internal clock may be used for determining the time period. The time period may be for example one or more hours. If no value (Zi) is found in the time period, because for example the user did not use the aerosol generating device <NUM> in the time period then the last calculated average value of the amount (Zav) of charge needed to fully use one consumable article <NUM> is used.

After the number of consumable articles <NUM> that can be fully used with the amount of charge remaining in the battery <NUM> is calculated as elaborated above, the control unit <NUM> carries out the step of displaying information indicating the calculated number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM>. The control unit <NUM> carrying out the step of displaying information indicating the calculated number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM> may involve the control unit <NUM> sending an instruction to the output unit <NUM> to display information indicating the calculated number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM>.

The step of displaying information indicating the calculated number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM> may comprise displaying numerical information (numerical representation) or displaying visual or graphical information (graphical representation).

The numerical representation may comprise displaying in the output means <NUM> the calculated number as shown in <FIG>, in this case displaying the number <NUM>. Normally there is no restriction as to the maximum number that can be displayed in this way. In this case the output unit <NUM> may be a liquid crystal display or LED display.

The visual or graphical representation may involve the use of indicators in the output unit <NUM> as shown in <FIG>. The indicators may be LEDs in the form of shapes or symbols, such as dots, circles, triangles, rectangles and similar, placed on a suitable position on the aerosol generating device with enough separation to see individual ones. In other words, the output unit <NUM> may comprise a plurality of LEDs. The LEDs are lit (illuminated) to show how many consumable articles <NUM> can be fully used with the determined amount of charge remaining in the battery <NUM>. The number of illuminated LEDs represents the number of consumable articles that can be fully used with the determined amount of charge remaining in the battery <NUM>. In other words, the step of displaying information indicating the calculated number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM> comprises a step of illuminating one or more indicators based on said calculated number. In this embodiment the number of illuminated indicators is equal to the calculated number.

In this embodiment of the present invention the indicators are arranged at the top portion of the housing <NUM> close to the opening <NUM> through which the user inserts the consumable article <NUM> in the heating chamber <NUM> as shown in <FIG>. This position of the indicators, or in other words, this position of the output unit <NUM> enables that the user sees without difficulty the displayed information when opening the access portion <NUM> to insert the consumable article <NUM> in the heating chamber <NUM>. Even further, with arrangement the indicators at the top portion of the housing portion <NUM> the surface where the user normally handhelds the aerosol generating device <NUM> is not disturbed by the indicators so that the physical ergonomic advantage of the surface to the user is not disturbed.

In this embodiment the number of arranged indicators in the output unit <NUM> is equal to the maximum number of consumable articles that can be fully used when the battery <NUM> is fully charged.

In other embodiment of the present invention the number of arranged indicators in the output unit <NUM> may be smaller than the number of consumable articles <NUM> that can be fully used when the battery <NUM> is fully charged. One such embodiment is described further below.

The control unit <NUM> may further instruct the transmitting/receiving means to transmit the calculated number of consumable articles <NUM> that can be fully used with the amount of charge remaining in the battery <NUM> to an external device that displays the information indicating the number of consumable articles <NUM> that can be fully used with the amount of charge remaining in the battery <NUM>. The external device may be for example a smartphone <NUM> or other electronic device for personal use or a charging case <NUM> as illustrated in <FIG>.

Hence, the graphical or numerical representation of the number of consumable articles that can be fully used with the determined amount of charge remaining in the battery <NUM> is performed by the external device, for example the smartphone <NUM> or the charging case <NUM>.

The smartphone <NUM> may have installed on it an application software for carrying out numerical representation <NUM> of the number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM> as shown in <FIG> or graphical representation <NUM> of the number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery as shown in <FIG>. In the numerical representation <NUM> additional text information may be included as shown in <FIG>. In the graphical representation <NUM> shapes, such as for example circles, corresponding to the calculated number may be displayed as shown in <FIG>.

The charging case <NUM> may comprise output means similar to the output means <NUM> of the aerosol generating device <NUM> for displaying the calculated number.

In one embodiment of the present invention the control unit <NUM> may further transmit the determined amount of charge remaining in the battery to the smartphone <NUM> or other electronic device for personal use, such that the step of calculating the number of consumable articles as elaborated is performed by the smartphone <NUM> (or the other electronic device for personal use) instead of, or in addition to, performing this step by the control unit <NUM>.

In other words, if the aerosol generating device <NUM> can connect with the application software of the smartphone <NUM> the aerosol generating device <NUM> transmits the determined amount of charge remaining in the battery to the smartphone <NUM> and the application software of the smartphone <NUM> carries out the step of calculating the number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM> as elaborated above and subsequently carries out the step of displaying information indicating the calculated number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM> as elaborated above.

The aerosol generating device <NUM> may connect with the external device such as the smartphone <NUM>, or other electronic device for personal use, or the charging case <NUM> by means of wireless or wired communication. For this, the transmitting/receiving means <NUM> of the aerosol generating device <NUM> may be configured for performing wired or wireless communication. The wireless communication may involve for example short-range wireless communication or long-range communication wireless.

As elaborated above the control unit <NUM> may be triggered to determine the first value (Y) for the amount of charge remaining in the battery <NUM> based on a pre-determined triggering signal received by the control unit <NUM>. In accordance with the above description triggering is to be understood not only as triggering for determining the first value (Y) for the amount of charge remaining in the battery <NUM> but as triggering for indicating the battery level of the battery <NUM> of the aerosol generating device <NUM> by carrying out the steps of the method elaborated with reference to <FIG> above.

In one embodiment of the present invention the triggering may involve for example the user opening the access portion <NUM>, for example by moving the slider to open (for example before starting an aerosol generating session) or close (for example after an aerosol generating session is completed) the opening <NUM> to the heating chamber <NUM>. Accordingly, when the user opens the slider to open the opening <NUM> to the heating chamber <NUM> for inserting a consumable article <NUM> the steps of the method described with reference to <FIG> are carried out and the battery level is indicated as elaborated above. In this way there is no need for the user to further manipulate the aerosol generating device <NUM> for initiating the battery level indication. This is advantageous since it is not necessary that further means are provided on the aerosol generating device <NUM> for initiating the battery level indication. It also improves user experience since it informs the user of the remaining battery level (i.e., how may tobacco sticks/consumable articles can be vaped/used) before starting an aerosol generating session. This is particularly useful if the remaining battery level is not sufficient for finishing one aerosol generating session (for example vape one tobacco stick). Similarly, when the user closes the slider to close the opening <NUM> to the heating chamber <NUM> after the aerosol generating session is completed the steps of the method described with reference to <FIG> are carried out and the battery level is indicated as elaborated above. Such battery indication right after vaping is advantageous to help the user predict battery charging and/or the next aerosol generating session.

In other embodiment of the present invention the triggering may involve the user pressing one or more of the buttons of the input unit <NUM>, or the user inserting the consumable article <NUM> in the heating chamber <NUM>, or the user tapping lightly on the device, waving or shaking the device.

In still other embodiment of the present invention the triggering may follow through the external device, for example, the user manipulating the external device, for example the smartphone <NUM>, to request battery indication, for example, through the application software described above.

In the embodiment elaborated above with reference to <FIG> the graphical representation of the information indicating the calculated number of consumable articles that can be fully used with the determined amount of charge remaining in the battery <NUM> involved illuminating a number of LEDs (indicators), said number of illuminated LEDs being equal to the calculated number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM>. This approach requires rather large number of arranged LEDs on the aerosol generating device <NUM> since the number of LEDs that can be illuminated should be equal to the number of consumable articles <NUM> that can be fully used when the battery <NUM> is fully charged. In other words, the size of the output unit <NUM> is in such case rather large. Therefore, rather large surface for arranging such large number of LEDs (the output unit <NUM>) on the aerosol generating device <NUM> is needed.

However, due to the limited size of the aerosol generating device <NUM> that is a handheld device as elaborated above it may be preferred that the number of LEDs arranged on the aerosol generating device <NUM> is smaller than the number of consumable articles <NUM> that can be fully used when the battery <NUM> is fully charged. Therefore, there is a need for determining an illumination pattern with which the information indicating the calculated number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM> can be displayed in a manner that is easily comprehendible for the user without any harm to the clean design of the aerosol generating device <NUM> and without disturbing the physical ergonomic advantage such design has for the user as well as being in compliance with the limited size of the aerosol generating device <NUM>.

Therefore, in a further embodiment of the present invention a predetermined number of indicators that can be illuminated in the output unit <NUM> is arranged on the aerosol generating device <NUM> and this predetermined number is smaller than the number of consumable articles <NUM> that can be fully used when the battery <NUM> is fully charged.

In this embodiment of the present invention an illumination pattern for illuminating the indicators based on the calculated number of consumable articles <NUM> and a predetermined threshold is determined. Determining an illumination pattern for the indicators comprises determining a number of indicators to be illuminated of the predetermined number of arranged indicators and determining a colour of illumination based on the calculated number of consumable articles <NUM> and the predetermined threshold. The predetermined threshold may be the predetermined number of indicators arranged on the aerosol generating device <NUM> or may be a multiple of the predetermined number indicators arranged on the aerosol generating device <NUM>.

The indicators may be LEDs that are capable of emitting light in different colours.

In one embodiment of the present invention the predetermined number of LEDs is four. In this embodiment of the present invention each LED is capable of emitting light at least in three different colours.

<FIG> shoes schematic view of the arrangement of the four LEDs (output unit <NUM>) on the aerosol generating device <NUM>. As shown in <FIG> the four LEDs are arranged in a line along the direction of extending of the housing portion <NUM> and are arranged in the lower part of the housing portion <NUM>. Since the four LEDs are arranged in the lower part of the aerosol generating device <NUM> they are arranged away from the position of handholding the aerosol generating device <NUM> so that the physical ergonomic advantage of the contact surface of the aerosol generating device <NUM> with the hand of the user is not disturbed.

Details of the illumination pattern are shown schematically in <FIG>.

A first colour of each LED, for example white colour, indicates that five consumable articles <NUM> may be fully used with the determined amount of charge remaining in the battery <NUM>. When there are four LEDs illuminated in the first colour, for example the white colour, this means that from sixteen to more than twenty consumable articles <NUM> may be fully used with the determined amount of charge remaining in the battery <NUM>.

When there are three LEDs illuminated in the first colour (and one LED is not emitting light, or is dark), this means that from eleven to fifteen consumable articles may be fully used with the determined amount <NUM> of charge remaining in the battery <NUM>.

When there are two LEDs illuminated in the first colour (and two other LEDs are dark) this means that from six to ten consumable articles <NUM> may be fully used with the determined amount of charge remaining in the battery <NUM>.

If there is one LED illuminated in the first colour (and three LEDs are dark) this means that five consumable articles <NUM> can be fully used with the determined amount of charge remaining in the battery <NUM>.

Once the calculated number of consumable articles <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM> reaches four, the colour of illumination is changed to a second colour, for example yellow. In this case each LED illuminated with the second colour corresponds to one consumable article <NUM> that can be fully used with the determined amount of charge remaining in the battery <NUM>. Therefore, when all four LEDs are illuminated with the second colour this means that four consumable articles <NUM> can be fully used with the determined amount of charge remaining in the battery <NUM>. When three LEDs are illuminated with the second colour (and one LED is dark) this means that three consumable articles <NUM> can be fully used with the determined amount of charge remaining in the battery <NUM>. When two LEDs are illuminated with the second colour (and two LEDs are dark) this means that two consumable articles <NUM> can be fully used with the determined amount of charge remaining in the battery <NUM>.

However, when the calculated number of consumable articles that can be fully used with the determined amount of charge remaining in the battery <NUM> is one than the colour of illumination is changed to a third colour, for example red. Accordingly one LED illuminated with red colour (for example the lowest LED in <FIG> and the other three LEDs being dark) indicates that only one consumable article <NUM> can be fully used with the determined amount of charge remaining in the battery <NUM>. In this way the user can easily understand that only one consumable article <NUM> can be fully used with the determined amount of charge remaining in the battery <NUM> and that charging of the battery <NUM> is needed.

In summary, in the above a method has been shown for indicating a battery level of a battery <NUM> of an aerosol generating device <NUM> in terms of the number of consumable articles <NUM> that can be fully used with the amount of charge remaining in the battery <NUM>. With this the user can easily understand how many consumable articles <NUM> may be fully used with the with the amount of charge remaining in the battery <NUM>. Further, the manner of displaying is also in accordance with the limited size of the aerosol generating device <NUM> and further does not disturb the physical ergonomic advantage of the contact surface of the aerosol generating device <NUM> with the hand of the user is not disturbed.

Claim 1:
A method of indicating a battery level of a battery (<NUM>) of an aerosol generating device (<NUM>) for generating an aerosol from an aerosol generating substance contained in a consumable article (<NUM>), the method comprising the steps of:
determining (S <NUM>) the amount of charge remaining in the battery (<NUM>);
calculating (S <NUM>) the number of consumable articles (<NUM>) that can be fully used with the determined amount of charge remaining in the battery (<NUM>); and
displaying (S <NUM>) an information, said information indicating the calculated number of consumable articles (<NUM>) that can be fully used with the determined amount of charge remaining in the battery (<NUM>).