Technical Field

The present invention relates to aerosol provision devices and methods of operating aerosol provision devices.

Background

Smoking articles such as cigarettes, cigars and the like bum tobacco during use to create tobacco smoke. Attempts have been made to provide alternatives to these articles that bum tobacco by creating products that release compounds without burning. Examples of such products are heating devices which release compounds by heating, but not burning, the material. The material may be for example tobacco or other non tobacco products, which may or may not contain nicotine.

Summary

According to a first aspect of the present disclosure, there is provided an aerosol provision device, comprising:

a heater assembly configured to heat aerosol generating material;

an indicator assembly; and

a controller, configured to:

cause the heater assembly to heat the aerosol generating material;

determine a characteristic of the heater assembly; and

if the determined characteristic satisfies at least one criterion, cause the indicator assembly to indicate that the device is ready for use.

According to another aspect of the present disclosure, there is provided an aerosol provision device, comprising:

a heater assembly configured to heat aerosol generating material;

an indicator assembly;

a temperature sensor arranged to provide an output indicative of a temperature of the heater assembly; and

a controller, configured to: cause the heater assembly to heat the aerosol generating material; receive the output from the temperature sensor;

determine a temperature of the heater assembly based on the output from the temperature sensor; and

if the determined temperature satisfies at least one criterion, cause the indicator assembly to indicate that the device is ready for use.

According to a second aspect of the present disclosure, there is provided a method of operating an aerosol provision device, comprising:

causing a heater assembly of the device to heat aerosol generating material; determining a characteristic of the heater assembly; and

if the determined characteristic satisfies at least one criterion:

causing an indicator assembly of the device to indicate that the device is ready for use.

According to another aspect of the present disclosure, there is provided a method of operating an aerosol provision device, comprising:

causing a heater assembly of the device to heat aerosol generating material; determining a temperature of the heater assembly based on an output from a temperature sensor; and

if the determined temperature satisfies at least one criterion:

causing an indicator assembly of the device to indicate that the device is ready for use.

According to a third aspect of the present disclosure, there is provided an aerosol provision device, comprising:

an inductor coil for generating a varying magnetic field;

a susceptor arranged to heat aerosol generating material, wherein the susceptor is heatable by penetration with the varying magnetic field;

an indicator assembly; and

a controller, configured to: cause the inductor coil to begin generating the varying magnetic field; and

cause the indicator assembly to indicate that the device has finished operating or is about to finish operating within a predetermined period of time after causing the inductor coil to begin heating the aerosol generating material.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments of the invention, given by way of example only, which is made with reference to the accompanying drawings.

Brief Description of the Drawings

Figure 1 shows a front view of an example of an aerosol provision device; Figure 2 shows a front view of the aerosol provision device of Figure 1 with an outer cover removed;

Figure 3 shows a cross-sectional view of the aerosol provision device of Figure i ;

Figure 4 shows an exploded view of the aerosol provision device of Figure 2; Figure 5A shows a cross-sectional view of a heating assembly within an aerosol provision device;

Figure 5B shows a close-up view of a portion of the heating assembly of Figure 5A;

Figure 6 shows a front view of the device;

Figure 7 shows a perspective view of the housing of the device;

Figure 8 shows a perspective view of the device without the housing;

Figure 9 depicts a perspective view of LEDs arranged within the device;

Figure 10 shows an outer member comprising a plurality of apertures;

Figure 11 shows components of the device arranged above the LEDs;

Figure 12 shows a system comprising a controller, a heater assembly, an input interface and an indicator assembly;

Figures 13A-D show the outer member illuminated by a plurality of LEDs; Figure 14 shows a flow diagram of a method of operating a device; and Figure 15 shows a flow diagram of a method of operating a device. Detailed Description

As used herein, the term“aerosol generating material” includes materials that provide volatilised components upon heating, typically in the form of an aerosol. Aerosol generating material includes any tobacco-containing material and may, for example, include one or more of tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes. Aerosol generating material also may include other, non-tobacco, products, which, depending on the product, may or may not contain nicotine. Aerosol generating material may for example be in the form of a solid, a liquid, a gel, a wax or the like. Aerosol generating material may for example also be a combination or a blend of materials. Aerosol generating material may also be known as“smokable material”.

Apparatus is known that heats aerosol generating material to volatilise at least one component of the aerosol generating material, typically to form an aerosol which can be inhaled, without burning or combusting the aerosol generating material. Such apparatus is sometimes described as an“aerosol generating device”, an“aerosol provision device”, a“heat-not-burn device”, a“tobacco heating product device” or a “tobacco heating device” or similar. Similarly, there are also so-called e-cigarette devices, which typically vaporise an aerosol generating material in the form of a liquid, which may or may not contain nicotine. The aerosol generating material may be in the form of or be provided as part of a rod, cartridge or cassette or the like which can be inserted into the apparatus. A heater for heating and volatilising the aerosol generating material may be provided as a“permanent” part of the apparatus.

An aerosol provision device can receive an article comprising aerosol generating material for heating. An“article” in this context is a component that includes or contains in use the aerosol generating material, which is heated to volatilise the aerosol generating material, and optionally other components in use. A user may insert the article into the aerosol provision device before it is heated to produce an aerosol, which the user subsequently inhales. The article may be, for example, of a predetermined or specific size that is configured to be placed within a heating chamber of the device which is sized to receive the article.

A first aspect of the present disclosure defines an aerosol provision device comprising a controller configured to (i) cause a heater assembly to heat the aerosol generating material, (ii) determine a characteristic of the heater assembly, and (iii) if the determined characteristic satisfies at least one criterion, cause the indicator assembly to indicate that the device is ready for use.

The device can therefore measure or monitor a characteristic of the heater assembly and responsively notify a user when the device is ready to use based on the characteristic. The device can therefore inform the user that they can begin using the device. This can avoid having the user wait for longer than necessary to inhale the aerosol, which can waste aerosol and reduce customer satisfaction.

In a particular example, the characteristic is a temperature of the heater assembly. The controller may therefore determine a temperature of the heater assembly and responsively cause the indicator assembly to indicate the device is ready for use when the temperature satisfies at least one criterion. The temperature of the aerosol generating material being heated by the heater assembly may be dependent upon the temperature of the heater assembly.

The temperature may be measured by a temperature sensor. Accordingly, the device may comprise a temperature sensor configured to provide an output (such as a signal) indicative of a temperature of the heater assembly (such as a component of a heater assembly). The controller receives the output from the temperature sensor to determine/calculate the temperature based on the output. If the temperature meets/satisfies a criterion, the controller can cause an indicator assembly of the device to provide an indication that the device is ready for use. The device can therefore measure or monitor the temperature of the heater assembly and responsively notify a user when the device is ready to use based on the temperature.

The temperature of the heater assembly may be measured or inferred by other means. For example, the heater assembly may comprise a susceptor. The susceptor may comprise two or more different materials having different Curie temperatures. When a material reaches its Curie temperature (as it is heated) its properties may change. This change in state may be detectable by circuitry within the device. The controller may therefore determine that a material has reached its Curie temperature without directly measuring the temperature using a more standard temperature sensor.

“If the determined characteristic satisfies at least one criterion, cause the indicator assembly to indicate that the device is ready for use” can mean“determining that the characteristic satisfies at least one criterion; and in response to determining that the characteristic satisfies the criterion, causing the indicator assembly to indicate that the device is ready for use”.

The at least one criterion may be satisfied when the determined temperature is greater than or equal to a threshold temperature. Thus, only when the temperature has exceeded the threshold is the user informed that the device is ready for use. This can ensure that the aerosol generating material has been heated to a minimum temperature. At this threshold temperature, the aerosol generating material may have released a sufficient volume/concentration of aerosol. Below this threshold, the aerosol may be less suitable for inhalation.

The controller may be configured to cause the indicator assembly to indicate that the device is ready for use a predetermined period of time after it is determined that the determined temperature satisfies the at least one criterion. During the predetermined period of time, the temperature of heater assembly may fluctuate above and below the threshold as the heater assembly is driven to maintain its temperature. Thus, the temperature may not always be greater than or equal to the threshold. The predetermined period of time allows time for the heat to penetrate into the aerosol generating material. The user can then be notified that the device is ready for use at a later time. In one example, the predetermined period of time is greater than about 10 seconds, greater than about 15 seconds, or greater than about 20 seconds after the heater has reached the threshold temperature.

In an alternative example, the at least one criterion may be satisfied when the determined temperature has been greater than or equal to a threshold temperature for at least a predetermined period of time. Accordingly, the aerosol generating material may have been heated at or above this temperature for a certain length of time. This can ensure that the heat has had time to penetrate into the aerosol generating material, which can generate a higher volume/concentration of aerosol. For example, at the point the temperature exceeds the threshold, the aerosol generating material may still be at a relatively low temperature. The predetermined period of time may be greater than about 10 seconds, greater than about 15 seconds, or greater than about 20 seconds after the heater has reached the threshold temperature.

The heater may reach the threshold temperature in less than about 5 seconds, or less than about 3 seconds, or less than about 2 seconds after the controller causes the heater assembly to begin heating the aerosol generating material.

The threshold temperature may be the heater“setpoint”, i.e. the temperature at which the heater is maintained for at least a portion of the heating session. During a heating session there may be different threshold temperatures.

The threshold temperature may be greater than about 240°C, greater than about 250°C, greater than about 260°C, greater than about 270°C, greater than about 280°C, or greater than about 290°C. The threshold temperature may be greater than about 240°C and less than about 290°C, greater than about 250°C and less than about 260°C, or greater than about 280°C and less than about 290°C. In some examples, the device is configured to operate in one of a first mode and a second mode, the first mode having different heating characteristics to the second mode, wherein the threshold temperature is different in the first mode than in the second mode. For example, the threshold temperature may be higher in the second mode. In some examples, the predetermined period of time is the same in both heating modes. In other examples, the predetermined period of time is different in the first mode than in the second mode. For example, the predetermined period of time may be higher in the first mode because the threshold temperature may be lower.

The device can therefore operate in two or more different heating modes. In one example, each heating mode may heat the aerosol generating material to a different temperature, and/or may heat the aerosol generating material for a different length of time. Each heating mode can therefore have different characteristics.

In an example, in the first mode, the threshold temperature is between about 240°C and about 260°C and in the second mode, the threshold temperature is between about 270°C and about 290°C.

The device may also operate in other, non-heating modes. For example, the device may operate in a settings mode. The heating and non-heating modes may be known more generally as operating modes of the device.

The first mode may be known as a default mode, and the second mode may be known as a boost mode. The second mode may, for example, generate a higher volume or concentration of aerosol than the first mode.

The characteristic of the heater assembly may be energy used by the heater assembly. The controller may determine or calculate the energy used by the heater and cause the indicator assembly to indicate that the device is ready for use when the energy used by the heater assembly is greater than or equal to a threshold energy. The criterion may therefore be satisfied when the determined energy use is greater than or equal to a threshold. For example, the controller may determine when the heater assembly has used more than about 50J, or more than about 60J, or more than about 80J, or more than about 100J, or more than about 120J since the heater assembly began heating the aerosol generating material. By measuring the energy used, the device may not need a temperature sensor, which can reduce the number of components a device needs.

The threshold may be a percentage of the total energy used in a heating session. The controller may determine when the heater assembly has used more than about 2% of the total energy used in a heating session, or more than about 3%, or more than about 5%, or more than about 7%, or more than about 10%, for example.

In some examples, the device further comprises an input interface configured to receive an input for operating the device. In one example the input interface is configured to receive an input for selecting a heating mode from a plurality of heating modes comprising a first mode and a second mode. Thus, a user can interact with, or operate the input interface to select a heating mode. The controller can detect the input for selecting the heating mode, and in response to detecting the input the controller can determine a selected heating mode based on the input and can cause the heater assembly to begin heating the aerosol generating material according to the selected heating mode. The same input interface may be used to receive an input for selecting a settings mode from the plurality of operating modes. Accordingly, in some examples, the device only begins heating once a heating mode has been selected. This allows the device to be more energy efficient.

Preferably, the controller causes the heater assembly to begin heating the aerosol generating material according to the selected heating mode at substantially the same time as determining the selected heating mode. For example, they may occur simultaneously. This reduces the time the user needs to wait until they begin using the device. In other examples there may be a small delay between these steps, such as less than 1 second, less than 0.5 seconds, less than 0.1 seconds, less than 0.01 seconds, or less than 0.001 seconds. In some examples the indicator assembly provides an indication that the heater assembly has begun to heat the aerosol generating material. This can avoid the user trying to start operation of the device again.

In one arrangement, the indicator assembly comprises a visual component configured to indicate that the device is ready for use. For example, the visual component may comprise an LED, a plurality of LEDs, a display, an elnk display, or a mechanical element which moves to display one or more patterns, for example. In some examples, the visual component is configured to emit light.

In a particular example, the indicator assembly comprises a plurality of LEDs, and the number of illuminated LEDs indicates when the device is ready for use. For example, when the heater assembly first begins to heat the aerosol generating material there may be a first number of LEDs illuminated and when the device is ready for use there may be a second number of LEDs illuminated, where the second number is greater than the first number. The first number of LEDs may be zero. The second number may be all of the LEDs. The indicator assembly may therefore indicate how close the device is to being ready for use. The LEDs may be sequentially illuminated as the heater assembly is heated. The LEDs may be sequentially illuminated based on the temperature measured by the temperature sensor.

In a particular example there are a plurality of LEDs, such as four LEDs, and the LEDs are sequentially switched on based on the temperature of the heater assembly (i.e. as the heater assembly is heated). For example, all four LEDs may initially be switched off. When the temperature increases beyond a first threshold, one of the four LEDs may be switched on. When the temperature increases beyond a second threshold, another LED may be switched on. When the temperature increases beyond a third threshold, another LED may be switched on, and when the temperature increases beyond a fourth threshold, all four LEDs may be switched on. The fourth threshold may be equal to the threshold temperature described above. Thus, all of the LEDs may be illuminated at the point the temperature is equal to the threshold temperature. In another example there are a plurality of LEDs, such as four LEDs, and the LEDs are sequentially switched on after the controller has determined that the temperature is greater than or equal to the threshold temperature. For example, all four LEDs may initially be switched off. One of the four LEDs may be switched on when a first threshold period of time has passed after the controller has determined that the temperature is greater than or equal to the threshold temperature. The first threshold period of time may be zero seconds (i.e. the LED may be switched on at the point the controller has determined that the temperature is greater than or equal to the threshold temperature). A second LED may be switched on when a second threshold period of time has passed after the controller has determined that the temperature is greater than or equal to the threshold temperature. A third LED may be switched on when a third threshold period of time has passed after the controller has determined that the temperature is greater than or equal to the threshold temperature. The final LED may be switched on when a fourth threshold period of time has passed after the controller has determined that the temperature is greater than or equal to the threshold temperature.

In another example, the indicator assembly comprises a haptic component configured to provide haptic feedback to indicate that the device is ready for use. For example, the haptic component may be a haptic motor which causes the device to vibrate when the device is ready for use. In some examples the haptic component provides haptic feedback according to a first pattern after the heater assembly begins to heat the aerosol generating material and provides haptic feedback according to a second pattern when the device is ready for use. The first pattern may last until the device is ready for use or may terminate after a short time. Accordingly, the haptic component may also indicate that the device has begun heating the aerosol generating material so that the user is aware the device is operating.

In another example, the indicator assembly comprises an audible indicator configured to emit sound to indicate that the device is ready for use. The audible indicator may be a transducer, buzzer, beeper, etc. In a particular example, the indicator assembly comprises a haptic component and a visual component. The haptic component may be configured to provide a haptic indication that the heater assembly has begun heating the aerosol generating material. The visual component may be configured to provide a visual indication that the device is ready for use.

In some examples the indicator assembly is configured to provide an indication indicative of the time left until the device finishes operating. For example, the indicator assembly may provide different indications depending upon the time left until the device finishes operating. The device may“finish operating” at the time the the heater assembly stops being powered (i.e. it is no longer actively heating or maintaining a temperature), or at the time the aerosol temperature/volume is considered to fall below an acceptable level, which may be several seconds after point at which the heater assembly has ceased being powered. In one example, the device may“finish operating” at the time the temperature of the heater assembly falls below a second threshold.

In a particular example, the indicator assembly comprises a plurality of LEDs, and the number of illuminated LEDs is indicative of the time left until the device finishes operating. For example, when the device is operating there may be a first number of LEDs illuminated and when the device has finished operating there may be a second number of LEDs illuminated, where the second number is less than the first number. The second number may be zero, for example. The first number may be all of the LEDs. The LEDs may therefore“count down” as the device gets closer to finishing.

In a particular example there are a plurality of LEDs, such as four LEDs, and the LEDs are sequentially switched off based on the temperature of the heater assembly (i.e. as the end of the heating session approaches). For example, all four LEDs may be illuminated before the device finishes operating. When the temperature drops by a first amount, one of the four LEDs may be switched off. When the temperature drops by a second amount, another LED may be switched off. When the temperature drops by a third amount, another LED may be switched off, and when the temperature falls below by a fourth amount, all four LEDs may be switched off. The first amount may be between about 5-10°C below the operating temperature of the heater assembly (i.e. the threshold temperature). The second amount may be between about 10-20°C below the operating temperature of the heater assembly (i.e. the threshold temperature). The third amount may be between about 15-30°C below the operating temperature of the heater assembly (i.e. the threshold temperature). The fourth amount may be between about 20- 40°C below the operating temperature of the heater assembly (i.e. the threshold temperature). The fourth amount may be equal to the second threshold described above.

In another example, the haptic component may provide different haptic feedback patterns based on the temperature of the heater assembly. For example, the haptic component may provide haptic feedback to indicate the decreasing temperature of the heater assembly (which may be indicative of the period of time remaining). The type of haptic feedback may be indicative of how much time is remaining.

In a further example, the audible indicator may provide different sounds based on the temperature of the heater assembly (which may be indicative of the time left). For example, the pitch, tone, sound pattern, etc. may change over time.

In another example, the controller is configured to cause the indicator assembly to indicate that the device has finished operating or is about to finish operating. Thus, the indicator assembly may indicate the moment at which it finishes operating, or is about to finish operating. For example, the when the device finishes operating the visual indicator may no longer provide any visual indication. In a particular example, all of the LEDs may be switched off when the device has finished operating or is about to finish operating. This indicates to the user that they should cease inhaling from the device.

The controller may cause the indicator assembly to indicate that the device has finished operating or is about to finish operating when the determined temperature satisfies a second criterion. The second criterion may be satisfied when the determined temperature is less than or equal to a second threshold temperature. The second threshold temperature may be lower than the threshold temperature. For example, the second threshold temperature may be between about 10°C and about 50°C below the temperature threshold described above.

In a particular example there are a plurality of LEDs, such as four LEDs, and the LEDs are sequentially switched off as the end of the heating session approaches. For example, all four LEDs may be illuminated 20 seconds before the device finishes operating. When only 15 seconds remain, one of the four LEDs may be switched off. When only 10 seconds remain, another LED may be switched off. When only 5 seconds remain another LED may be switched off, and when there are 0 seconds remaining all four LEDs may be switched off.

In another example, the haptic component may provide different haptic feedback patterns depending upon the time left. For example, the haptic component may provide haptic feedback to indicate that is a certain period of time remaining. The type of haptic feedback may be indicative of how much time is remaining. For example, when there are 20 seconds remaining, there may be a short, low intensity haptic feedback and when there are 5 seconds or 0 seconds remaining, the haptic feedback may be longer and more intense.

In a further example, the audible indicator may provide different sounds depending upon the time left. For example, the pitch, tone, sound pattern, etc. may change over time.

The heater assembly may be configured to heat the aerosol generating material such that the indictor assembly indicates that the device is ready for use within less than about 30 seconds or less than about 20 seconds or less than about 15 seconds or less than about 10 seconds after causing the heater assembly to begin heating the aerosol generating material.

It has been found that certain heating assemblies, such as inductive heating assemblies, are able to heat aerosol generating material to a suitable temperature within a reduced period of time when compared to other types of heating assemblies. Accordingly, a user of the device may be able to draw on the device to inhale the aerosol within less than about 20 seconds, for example. Because certain heating assemblies are able to heat the aerosol generating material quickly, the aerosol generating material will have released a sufficient amount of aerosol at the time the device indicates that the device is ready.

As mentioned, the device may be configured to operate in one of a first mode and a second mode and when the device is operated in the first mode a component of the heater assembly is to be heated to a first temperature, and when the device is operated in the second mode a component of the heater assembly is to be heated to a second temperature. The second temperature may be higher than the first temperature.

In some examples, the time at which the temperature satisfies the at least one criterion is based on the heating mode. For example, in the second mode the controller may be configured to cause the heater assembly to heat a component of the heater assembly to a higher temperature than in the first mode. In the second mode, the time at which the temperature satisfies the criterion may be less than when the device is operating in the first mode.

In some examples, the indicator assembly may indicate the selected heating mode. In some examples this indication is the same indication as that which indicates the device is ready for use. Thus the type of indication used to indicate that the device is ready for use may be based on the selected heating mode. In other examples the indication that indicates the selected heating mode may occur after the heating mode is selected, but before the device is ready for use. Thus, two separate indications may occur. A first indication may indicate the selected heating mode, and a second indication may indicate that the device is ready for use. This can allow the user to cancel the heating if they accidentally select the wrong mode. In a particular example the first indication is provided by a haptic component, and the second indication is provided by a visual component. This is useful because the user may be holding the device when they select the heating mode, but may place the device on a surface as they wait for the device to be ready for use. The visual indication can be more easily seen if the user is no longer holding the device.

The input interface may also be known as a user interface. The input interface may be a button, touch screen, dial, knob, or a wireless connection to a mobile device (e.g. Bluetooth). The interface allows the user to select an operating mode from a plurality of operating modes. The operating modes may include one or more heating modes and/or a settings mode. When an input is received, the input interface can send one or more signals to the controller indicative of the input. Based on the signal(s), the controller can determine a selected operating mode, such as a selected heating or settings mode.

In a particular example, the input interface comprises a button, and the input comprises a signal indicating the button has been released. The controller can receive the input from the input interface. Thus, the heater assembly begins heating the aerosol generating material only once the button has been released. While the user is holding down the button, the heater assembly may not heat the aerosol generating material. The predetermined period of time therefore initiates when a user releases the button. The button may be a software button or a hardware button. The signal may be a single signal, or may be two or more signals.

In a particular example, the input further comprises a signal indicating a length of time that the button has been pressed and the controller is configured to detect the input for selecting a heating mode in response to (i) receiving the signal indicating that the button has been released, and (ii) determining that the length of time that the button has been pressed is greater than or equal to a threshold time period. The signal indicating the length of time that the button has been pressed may be part of the same signal which indicates that the button has been released, or may be a separate signal. Thus, in some examples, the heater assembly may only begin heating if the button is pressed for a certain length of time that is greater than or equal to a threshold time period. In a particular example, the threshold time period is 3 seconds or 5 seconds. If the button is held and released for less than the threshold time period, the heater assembly may not begin heating. This can avoid heating the aerosol generating material if the user accidentally presses of the button, which can waste energy. Thus, if the controller determines that the length of time that the button has been pressed is less than the threshold, the controller determines not to cause the heater assembly to begin heating.

The controller may be configured to determine a selected heating mode based on the length of time the button was pressed. In one example, the device is configured to operate in the first mode if the length of time that the button has been pressed is greater than or equal to a first threshold time period and is less than a second threshold time period, and the device is configured to operate in the second mode if the length of time that the button has been pressed is greater than or equal to the second threshold time period. The first threshold time period may be 3 seconds, and the second threshold time period may be 5 seconds, for example. Thus, using a single button the user can select different modes. Having a single interface to select multiple modes can simplify operation of the device and reduce the number of components. A reduced number of components can make the device more lightweight and there are fewer parts to break or stop functioning.

The heater assembly may be an inductive heater assembly. For example, the heater assembly may comprise one or more inductor coils and a susceptor. In another example, the heater assembly may be a resistive heater assembly. For example, one or more components may be heated resistively which heat the aerosol generating material.

In a particular example, the heater assembly comprises an inductor coil for generating a varying magnetic field and a susceptor arranged to heat the aerosol generating material, wherein the susceptor is heatable by penetration with the varying magnetic field. The controller is configured to cause the heater assembly to heat the aerosol generating material by causing the inductor coil to generate the varying magnetic field. Accordingly, the susceptor may be the component of the heater assembly which is heated. For example, in the first mode, the inductor coil may be configured to heat the susceptor to a first temperature. In the second mode, for example, the inductor coil may be configured to heat the susceptor to a second temperature. The temperature sensor therefore measures the temperature of the susceptor. The temperature sensor may be arranged between the susceptor and first inductor coil. Preferably the temperature sensor is located on the outer surface of the susceptor. The temperature sensor may be a thermistor or thermocouple.

It has been found that inductive heating systems are able to heat aerosol generating material to a suitable temperature within a reduced period of time when compared to other types of heating assemblies, such as resistive heating assemblies.

In some examples, the inductor coil is a first inductor coil, and the device further comprises a second inductor coil for generating a second varying magnetic field. In a particular arrangement, the first inductor coil is adjacent the second inductor coil in a direction along a longitudinal axis of the device, and the controller is configured to cause the second inductor coil to generate the second varying magnetic field after causing the indicator assembly to indicate that the device is ready for use. In use, the aerosol is drawn along a flow path of the device towards a proximal end of the device, and the first inductor coil is arranged closer to the proximal end of the device than the second inductor coil.

Accordingly, the device may comprise two inductor coils, where the first inductor coil is closer to a mouth end of the device. The first inductor coil therefore heats aerosol generating material which is closer to the mouth of the user. Initially the first inductor coil is operated. The second inductor coil can be operated at a later time. For example, the controller may cause the second inductor coil to generate the second magnetic field at a third predetermined time after causing the first inductor coil to generate the first magnetic field. The third predetermined time may be between about 40 seconds and about 60 seconds, for example. The third predetermined time may depend upon the mode in which the device is operating.

The first inductor coil may continue to generate the first magnetic field while the second inductor coil is generating the second magnetic field. In a particular example, the first inductor coil has a first length, second inductor coil has a second length, and the first length is shorter than the second length. A shorter length heats a lower volume of aerosol generating material, which generates a lower volume of aerosol, thereby reducing the phenomenon known as“hot puff’.

In another aspect, there is provided a method of operating the aerosol provision device described above. The method comprises causing a heater assembly of the device to heat aerosol generating material, determining a characteristic of the heater assembly. If the determined characteristic satisfies at least one criterion, causing an indicator assembly of the device to indicate that the device is ready for use.

The characteristic may be a temperature of the heater assembly. For example, in inductive heating systems, it may be a temperature of a susceptor.

The at least one criterion may be satisfied when the determined temperature is greater than or equal to a threshold temperature. The method may further comprise causing the indicator assembly to indicate that the device is ready for use a predetermined period of time after it is determined that the determined temperature satisfies the at least one criterion.

The method may further comprise causing the indicator assembly to indicate that the device is ready for use within less than about 30 seconds after causing the heater assembly to begin heating the aerosol generating material.

The method may further comprise causing the indicator assembly to indicate that the device has finished operating or is about to finish operating within a predetermined period of time after causing the heater assembly to begin heating the aerosol generating material. Although this method is described in relation to any type of heater assembly, it will be appreciated that this method may also be applied to a device with an inductive heater assembly.

In another aspect, an aerosol provision device comprises an inductor coil for generating a varying magnetic field, a susceptor arranged to heat aerosol generating material, wherein the susceptor is heatable by penetration with the varying magnetic field, an indicator assembly, and a controller. The controller is configured to cause the inductor coil to begin generating the varying magnetic field, and cause the indicator assembly to indicate that the device has finished operating or is about to finish operating within a predetermined period of time after causing the inductor coil to begin heating the aerosol generating material. Thus the user can be informed when the device has finished operating or is about to finish operating. This stops the user from continuing to use the device when the aerosol generated may no longer be of sufficient volume, concentration or temperature.

In another aspect, a method of operating an aerosol provision device, comprises causing an inductor coil of the aerosol provision device to generate a varying magnetic field for heating a susceptor and causing an indicator assembly of the aerosol provision device to indicate that the device has finished operating or is about to finish operating within a predetermined period of time after causing the inductor coil assembly to begin heating the aerosol generating material.

Although this method is described in relation to an inductive heater, it will be appreciated that this method may also be applied to a device with a non-inductive heater assembly. For example, instead of an inductor coil, the device may comprise a heater assembly configured to heat aerosol generating material.

In a particular example, the indicator assembly comprises one or more Light Emitting Diodes (LEDs) and an outer member positioned above the one or more LEDs. The outer member comprises a plurality of apertures visible from outside the aerosol provision device. Electromagnetic radiation (in the form of visible light for example) can pass through the plurality of apertures and be viewed by a user. At least a portion of the outer member may form an outer surface of the device.

The indicator assembly may further comprise a light-shaping member positioned between the one or more LED and the outer member. The light shaping member may comprise one or more light pipes to guide light through the light-shaping member to produce a particular pattern or design. The light-shaping member may comprise opaque regions configured to block a portion of the light from the LEDs. The light-shaping member may comprise transparent or translucent regions to allow the light to pass through. The light-shaping member may alternatively comprise openings to allow the light to pass through. A light-shaping member that comprises opaque regions and transparent or translucent regions may be more robust than a light-shaping member with openings. Translucent regions can also additionally diffuse/soften the light.

In some examples, the light shaping member is formed from two or more overmolded components. For example, the opaque and transparent/translucent regions may be formed from two overmolded components.

In one example, the light-shaping member comprises an opaque region extending around the periphery/perimeter/circumference of the light-shaping member. This can prevent light from leaking around the outside of the outer member. The opaque region may be an outer ring.

In one example the opaque region is coloured black or dark grey.

In one example, the opaque region is cross-shaped.

In a specific example, the device comprises four LEDs, wherein each of the four LEDs is located below the light-shaping member and are positioned between adjacent opaque regions such that the light from the LEDs separates into 4 quadrants. The opaque regions are configured to prevent light bleed from one quadrant to the adjacent quadrant.

Preferably, the device is a tobacco heating device, also known as a heat-not- burn device.

Figure 1 shows an example of an aerosol provision device 100 for generating aerosol from an aerosol generating medium/material. In broad outline, the device 100 may be used to heat a replaceable article 110 comprising the aerosol generating medium, to generate an aerosol or other inhalable medium which is inhaled by a user of the device 100.

The device 100 comprises a housing 102 (in the form of an outer cover) which surrounds and houses various components of the device 100. The device 100 has an opening 104 in one end, through which the article 110 may be inserted for heating by a heating assembly. In use, the article 110 may be fully or partially inserted into the heating assembly where it may be heated by one or more components of the heater assembly.

The device 100 of this example comprises a first end member 106 which comprises a lid 108 which is moveable relative to the first end member 106 to close the opening 104 when no article 110 is in place. In Figure 1, the lid 108 is shown in an open configuration, however the cap 108 may move into a closed configuration. For example, a user may cause the lid 108 to slide in the direction of arrow“A”.

The device 100 may also include an input interface 112, which may comprise a button or switch, which operates the device 100 when pressed. For example, a user may turn on the device 100 by operating the input interface 112.

The device 100 may also comprise an electrical connector/component, such as a socket/port 114, which can receive a cable to charge a battery of the device 100. For example, the socket 114 may be a charging port, such as a USB charging port. In some examples the socket 114 may be used additionally or alternatively to transfer data between the device 100 and another device, such as a computing device.

Figure 2 depicts the device 100 of Figure 1 with the outer cover 102 removed and without an article 110 present. The device 100 defines a longitudinal axis 134.

As shown in Figure 2, the first end member 106 is arranged at one end of the device 100 and a second end member 116 is arranged at an opposite end of the device 100. The first and second end members 106, 116 together at least partially define end surfaces of the device 100. For example, the bottom surface of the second end member 116 at least partially defines a bottom surface of the device 100. Edges of the outer cover 102 may also define a portion of the end surfaces. In this example, the lid 108 also defines a portion of a top surface of the device 100.

The end of the device closest to the opening 104 may be known as the proximal end (or mouth end) of the device 100 because, in use, it is closest to the mouth of the user. In use, a user inserts an article 110 into the opening 104, operates the user control 112 to begin heating the aerosol generating material and draws on the aerosol generated in the device. This causes the aerosol to flow through the device 100 along a flow path towards the proximal end of the device 100.

The other end of the device furthest away from the opening 104 may be known as the distal end of the device 100 because, in use, it is the end furthest away from the mouth of the user. As a user draws on the aerosol generated in the device, the aerosol flows away from the distal end of the device 100.

The device 100 further comprises a power source 118. The power source 118 may be, for example, a battery, such as a rechargeable battery or a non-rechargeable battery. Examples of suitable batteries include, for example, a lithium battery (such as a lithium-ion battery), a nickel battery (such as a nickel-cadmium battery), and an alkaline battery. The battery is electrically coupled to the heating assembly to supply electrical power when required and under control of a controller (not shown) to heat the aerosol generating material. In this example, the battery is connected to a central support 120 which holds the battery 118 in place. The central support 120 may also be known as a battery support, or battery carrier.

The device further comprises at least one electronics module 122. The electronics module 122 may comprise, for example, a printed circuit board (PCB). The PCB 122 may support at least one controller, such as a processor, and memory. The PCB 122 may also comprise one or more electrical tracks to electrically connect together various electronic components of the device 100. For example, the battery terminals may be electrically connected to the PCB 122 so that power can be distributed throughout the device 100. The socket 114 may also be electrically coupled to the battery via the electrical tracks.

In the example device 100, the heating assembly is an inductive heating assembly and comprises various components to heat the aerosol generating material of the article 110 via an inductive heating process. Induction heating is a process of heating an electrically conducting object (such as a susceptor) by electromagnetic induction. An induction heating assembly may comprise an inductive element, for example, one or more inductor coils, and a device for passing a varying electric current, such as an alternating electric current, through the inductive element. The varying electric current in the inductive element produces a varying magnetic field. The varying magnetic field penetrates a susceptor suitably positioned with respect to the inductive element, and generates eddy currents inside the susceptor. The susceptor has electrical resistance to the eddy currents, and hence the flow of the eddy currents against this resistance causes the susceptor to be heated by Joule heating. In cases where the susceptor comprises ferromagnetic material such as iron, nickel or cobalt, heat may also be generated by magnetic hysteresis losses in the susceptor, i.e. by the varying orientation of magnetic dipoles in the magnetic material as a result of their alignment with the varying magnetic field. In inductive heating, as compared to heating by conduction for example, heat is generated inside the susceptor, allowing for rapid heating. Further, there need not be any physical contact between the inductive heater and the susceptor, allowing for enhanced freedom in construction and application. The induction heating assembly of the example device 100 comprises a susceptor arrangement 132 (herein referred to as“a susceptor”), a first inductor coil 124 and a second inductor coil 126. The first and second inductor coils 124, 126 are made from an electrically conducting material. In this example, the first and second inductor coils 124, 126 are made from Litz wire/cable which is wound in a helical fashion to provide helical inductor coils 124, 126. Litz wire comprises a plurality of individual wires which are individually insulated and are twisted together to form a single wire. Litz wires are designed to reduce the skin effect losses in a conductor. In the example device 100, the first and second inductor coils 124, 126 are made from copper Litz wire which has a rectangular cross section. In other examples the Litz wire can have other shape cross sections, such as circular.

The first inductor coil 124 is configured to generate a first varying magnetic field for heating a first section of the susceptor 132 and the second inductor coil 126 is configured to generate a second varying magnetic field for heating a second section of the susceptor 132. In this example, the first inductor coil 124 is adjacent to the second inductor coil 126 in a direction along the longitudinal axis 134 of the device 100 (that is, the first and second inductor coils 124, 126 to not overlap). The susceptor arrangement 132 may comprise a single susceptor, or two or more separate susceptors. Ends 130 of the first and second inductor coils 124, 126 can be connected to the PCB 122

It will be appreciated that the first and second inductor coils 124, 126, in some examples, may have at least one characteristic different from each other. For example, the first inductor coil 124 may have at least one characteristic different from the second inductor coil 126. More specifically, in one example, the first inductor coil 124 may have a different value of inductance than the second inductor coil 126. In Figure 2, the first and second inductor coils 124, 126 are of different lengths such that the first inductor coil 124 is wound over a smaller section of the susceptor 132 than the second inductor coil 126. Thus, the first inductor coil 124 may comprise a different number of turns than the second inductor coil 126 (assuming that the spacing between individual turns is substantially the same). In yet another example, the first inductor coil 124 may be made from a different material to the second inductor coil 126. In some examples, the first and second inductor coils 124, 126 may be substantially identical.

In this example, the first inductor coil 124 and the second inductor coil 126 are wound in opposite directions. This can be useful when the inductor coils are active at different times. For example, initially, the first inductor coil 124 may be operating to heat a first section of the article 110, and at a later time, the second inductor coil 126 may be operating to heat a second section of the article 110. Winding the coils in opposite directions helps reduce the current induced in the inactive coil when used in conjunction with a particular type of control circuit. In Figure 2, the first inductor coil 124 is a right-hand helix and the second inductor coil 126 is a left-hand helix. However, in another embodiment, the inductor coils 124, 126 may be wound in the same direction, or the first inductor coil 124 may be a left-hand helix and the second inductor coil 126 may be a right-hand helix.

The susceptor 132 of this example is hollow and therefore defines a receptacle within which aerosol generating material is received. For example, the article 110 can be inserted into the susceptor 132. In this example the susceptor 120 is tubular, with a circular cross section.

The device 100 of Figure 2 further comprises an insulating member 128 which may be generally tubular and at least partially surround the susceptor 132. The insulating member 128 may be constructed from any insulating material, such as plastic for example. In this particular example, the insulating member is constructed from poly ether ether ketone (PEEK). The insulating member 128 may help insulate the various components of the device 100 from the heat generated in the susceptor 132.

The insulating member 128 can also fully or partially support the first and second inductor coils 124, 126. For example, as shown in Figure 2, the first and second inductor coils 124, 126 are positioned around the insulating member 128 and are in contact with a radially outward surface of the insulating member 128. In some examples the insulating member 128 does not abut the first and second inductor coils 124, 126. For example, a small gap may be present between the outer surface of the insulating member 128 and the inner surface of the first and second inductor coils 124, 126.

In a specific example, the susceptor 132, the insulating member 128, and the first and second inductor coils 124, 126 are coaxial around a central longitudinal axis of the susceptor 132.

Figure 3 shows a side view of device 100 in partial cross-section. The outer cover 102 is present in this example. The rectangular cross-sectional shape of the first and second inductor coils 124, 126 is more clearly visible.

The device 100 further comprises a support 136 which engages one end of the susceptor 132 to hold the susceptor 132 in place. The support 136 is connected to the second end member 116.

The device may also comprise a second printed circuit board 138 associated within the input interface 112.

The device 100 further comprises a second lid/cap 140 and a spring 142, arranged towards the distal end of the device 100. The spring 142 allows the second lid 140 to be opened, to provide access to the susceptor 132. A user may open the second lid 140 to clean the susceptor 132 and/or the support 136.

The device 100 further comprises an expansion chamber 144 which extends away from a proximal end of the susceptor 132 towards the opening 104 of the device. Located at least partially within the expansion chamber 144 is a retention clip 146 to abut and hold the article 110 when received within the device 100. The expansion chamber 144 is connected to the end member 106.

Figure 4 is an exploded view of the device 100 of Figure 1, with the outer cover 102 omitted. Figure 5A depicts a cross section of a portion of the device 100 of Figure 1. Figure 5B depicts a close-up of a region of Figure 5A. Figures 5A and 5B show the article 110 received within the susceptor 132, where the article 110 is dimensioned so that the outer surface of the article 110 abuts the inner surface of the susceptor 132. This ensures that the heating is most efficient. The article 110 of this example comprises aerosol generating material 110a. The aerosol generating material 110a is positioned within the susceptor 132. The article 110 may also comprise other components such as a filter, wrapping materials and/or a cooling structure.

Figure 5B shows that the outer surface of the susceptor 132 is spaced apart from the inner surface of the inductor coils 124, 126 by a distance 150, measured in a direction perpendicular to a longitudinal axis 158 of the susceptor 132. In one particular example, the distance 150 is about 3mm to 4mm, about 3mm to 3.5mm, or about 3.25mm.

Figure 5B further shows that the outer surface of the insulating member 128 is spaced apart from the inner surface of the inductor coils 124, 126 by a distance 152, measured in a direction perpendicular to a longitudinal axis 158 of the susceptor 132. In one particular example, the distance 152 is about 0.05mm. In another example, the distance 152 is substantially 0mm, such that the inductor coils 124, 126 abut and touch the insulating member 128.

In one example, the susceptor 132 has a wall thickness 154 of about 0.025mm to 1mm, or about 0.05mm.

In one example, the susceptor 132 has a length of about 40mm to 60mm, about 40mm to 45mm, or about 44.5mm.

In one example, the insulating member 128 has a wall thickness 156 of about 0.25mm to 2mm, about 0.25mm to 1mm, or about 0.5mm. Figure 6 depicts a front view of the device 100. As briefly mentioned above, the device may comprise an input interface 112. In some examples the user may interact with the input interface 112 to operate the device 100. Arranged in proximity to the input interface 112 may be an indicator assembly, which can indicate the occurrence of one or more events to a user, such as when the device is ready for use and/or when the device has finished operating. The indicator assembly may also indicate a mode in which the device 100 is operating.

Figure 6 depicts an outer member 202 positioned above (i.e. in front of) an indicator assembly. In other examples, the indicator assembly may be positioned elsewhere on the device. In the examples described herein, the indicator assembly comprises a visual component configured to provide a visual indication. The visual component comprises a plurality of LEDs which emit electromagnetic radiation, such as light, to indicate certain events to a user. It will be appreciated that indicator assembly may additionally or alternatively comprise a haptic component or an audible indicator. In the present device 100, the indicator assembly comprises a visual component and a haptic component.

The outer member 202 forms the outermost component of the input interface 112. A user may press the outer member 202 to interact with the device 100. As will be described in more detail below, the outer member 202 comprises a plurality of apertures 204 through which light from a plurality of LEDs can pass.

Figure 7 depicts the housing 102 (also known as the outer cover) of the device 100. The housing 102 delimits an opening 206. The outer member (not shown in Figure 7) can be arranged within the opening 206. For example, the outer member may be arranged flush with the outer surface of the housing 102, or may be raised above or below the outer surface of the housing 102.

Figure 8 depicts the device 100 without the housing 102 in place. In this example, the outer member 202 is adhered to a light-shaping member 210 via an adhesive layer 208. The adhesive in the adhesive layer 208 may partially or fully cover an inner surface of the outer member 202. Extending around the light-shaping member 210 is a sealing member 212.

In some examples the outer member 202, the adhesive layer 208, the light shaping member 210 and sealing member 212 may be omitted from the device.

Figure 9 depicts the device 100 with the outer member 202, light-shaping member 210 and sealing member 212 removed. The device 100 comprises a visual component comprising four LEDs 214, although in other examples there may be other numbers of LEDs, such as one or more LEDs 214. The LEDs 214 are positioned below the outer member 202 such that light travels from the LEDs 214 through the plurality of apertures 204 formed in the outer member 202. The light therefore also passes through the light-shaping member 210 and the adhesive layer 208. There may also be one or more additional components arranged between the LEDs 214 and the outer member 202.

In the example of Figure 9, the LEDs 214 are arranged around the input interface 112 which is configured to detect interactions from a user. For example, a user may press or otherwise operate the outer member 202 which in turn is detected by the input interface 112. The input interface 112 may be button or switch which is operated when a force is applied by the user to the outer member 202. In another example the input interface 112 and the outer member 202 may be part of a capacitive sensor which detects when a user touches the outer member 202.

Figure 10 depicts a front view of the outer member 202. As mentioned, the outer member 202 defines a plurality of apertures 204. In this example, the apertures 204 each form slots with a length and a width.

Preferably, the apertures 204 are arranged towards the perimeter/periphery/outer circumference of the outer member 202. As shown in Figure 10, the apertures 204 are arranged closer to the periphery of the outer member 202 than the centre of the outer member 202. This can allow the apertures 204 to be exposed (and therefore light to be seen) even when the user is pressing the outer member 202. The user may be more likely to press/hold the centre of the outer member 202 rather than an edge of the outer member 202.

Figure 11 is an exploded diagram showing some of the components of the device 100. As mentioned, the device 100 may comprise an adhesive layer 208 arranged between the LEDs 214 and the outer member 202. In the example shown, the adhesive layer is the same shape and size as the outer member 202 such that the adhesive covers the apertures 204. Light can then pass through the adhesive layer 208 before passing through the apertures 204. The adhesive layer 208 can therefore be transparent or translucent. A translucent adhesive layer 208 can help diffuse the light from the LEDs such that“hot spots” are avoided. A hot spot is a region where the light has a higher intensity than surrounding regions.

In some examples, the outer member 202 is attached to a light-shaping member 210 via the adhesive layer 208. In the example shown, the light shaping-member 210 comprises one or more opaque regions 230 (which may be joined together) and one or more translucent or transparent regions 232 (which may also be joined together). The translucent or transparent regions 232 may be known as light-pipes, since they guide light through the light-shaping member 210. Light from the LEDs 214 can pass through the translucent or transparent regions 232 but is blocked by opaque regions 230. The opaque regions 230 therefore reduce the intensity of light passing through a subset of the apertures 204 (i.e. those arranged above the opaque regions 230). The opaque regions 230 and the translucent or transparent regions 232 may be regions of a single monolithic component, but one or both regions may have been treated to give the region its specific optical property. In another example, the opaque regions 230 and the translucent or transparent regions 232 are separate components which are overmolded.

In this example, the light-shaping member comprises an opaque region 238 extending around the periphery/perimeter/circumference of the light-shaping member 210. This can prevent light from leaking around the outside of the outer member 202. The opaque region may be an outer ring, for example. In the present example, the device 100 comprises four LEDs 214, and each of the LEDs 214 is positioned between adjacent opaque regions 230 such that the light from the LEDs separates into 4 quadrants. In other words, the LEDs 214 may be arranged below the transparent or translucent regions. By separating the light into the different regions, different indications can be provided to a user. For example, the number of illuminated quadrants can specify certain events to a user. Accordingly, light may be blocked by the opaque regions such that the light may not pass through some of the apertures.

In some examples the regions between the opaque regions 230 are openings and therefore do not comprise translucent or transparent material.

Arranged between the light-shaping member 210 and the LEDs 214 is a sealing member 212, such as a gasket. The sealing member 212 has an outer diameter that is larger than the outer diameters of the outer member 202 and the light shaping member 210. In some examples the sealing member 210 abuts an inner surface of the housing 102 to stop liquid and dust from entering the device 100.

Indicating that the device is ready for use

Figure 12 depicts a system comprising a controller 302 (such as one or more processors), a heater assembly 304, a temperature sensor 308, an indicator assembly 306 and an input interface 112. In some examples the input interface 112 may be omitted. The controller 302 is communicatively coupled to the heater assembly 304, the temperature sensor 308, the indicator assembly 306 and the input interface 112 via one or more wired or wireless connections (shown as dashed lines).

The controller 302 may be located on the PCB 122, for example. The controller 302 can control operations of the device 100, such as causing the heater assembly 304 to heat aerosol generating material. In some examples, the controller 302 receives signals from the input interface 112, and responsively controls the heater assembly 304 and indicator assembly 306. A user can provide an input to the input interface 112 to operate the device. In certain examples a heating mode is selected via the input interface 112

As mentioned above, the indicator assembly 306 can indicate the occurrence of one or more events to a user. To cause the indicator assembly 306 to provide an indication, the controller 302 can send a signal or instruction to the indicator assembly 306. In the examples of Figures 6-11, the indicator assembly 306 comprises a visual component comprising a plurality of LEDs 214. It will be appreciated that the following discussion can be applied to other types of indicator assembly 306.

The temperature sensor 308 is arranged to measure a temperature of the heater assembly 304. For example, the temperature sensor 308 can measure the temperature of a susceptor 132. The temperature sensor 308 can provide an output (in the form of one or more signals, for example) that is indicative of a temperature of the heater assembly 304. The output can be received by the controller 302, which can determine a temperature based on the output. In some examples the output indicates the temperature. In other examples the output is used by the controller to calculate or determine the temperature. Accordingly, the controller 302 can monitor the temperature of a component of the heater assembly 304.

The controller 302 can control the heater assembly 304 based on the temperature. For example, the controller 302 can cause the heater assembly 304 to be maintained at, or close to, a threshold temperature. If the temperature exceeds the threshold temperature, the controller 302 can control the heater assembly 304 to reduce the temperature. For example, the controller 302 can temporarily stop the heater assembly 304 from heating, or can reduce the power output of the heater assembly 304. If the temperature is below the threshold temperature, the controller 302 can control the heater assembly 304 to increase the temperature. For example, the controller 302 can cause the heater assembly to start or continue heating, or can increase the power output of the heater assembly 304. In the following examples, the heater assembly 304 comprises one or more inductor coils which generate one or more magnetic fields to heat a susceptor. The controller 302 can cause the inductor coil(s) of the device 100 to generate a varying magnetic field. For example, the controller 302 can send one or more signals to the inductor coil(s). Once the inductor coil(s) have begun generating the varying magnetic field, the susceptor 132 is heated, which in turn heats any aerosol generating material located near to the susceptor 132. The temperature sensor 308 can therefore be arranged to measure the temperature of the susceptor 132. It will be appreciated that the following description may also apply to other types of heater assembly 304.

The controller 302 may cause one or more inductor coils to heat the susceptor to a threshold temperature of between about 240°C and about 290°C. In a specific example, the device is configured to operate in one of a first mode and a second mode, where the first and second modes are heating modes. In one example, when the device is operating in a first (default) mode, the controller 302 may cause the first inductor coil 124 to heat a first region of the susceptor 132 to a threshold temperature of between about 240°C and about 260°C, such as about 250°C. In another example, the device may be operating in a second (boost) mode, and the controller 302 may cause the first inductor coil 124 to heat a first region of the susceptor 132 to a threshold temperature of between about 270°C and about 290°C, such as about 280°C.

The second inductor coil 126 may generate a second magnetic field at a later time during the heating session. For example, the second inductor coil 126 may generate the second magnetic field between about 60 seconds and about 130 seconds after the first inductor coil 124 generates a first magnetic field. The second inductor coil is arranged to heat a second region of the susceptor 132. In some examples, both inductor coils 124, 126 operate at the same time.

After the first inductor coil 124 begins heating the susceptor 132, the controller 302 can periodically or continuously determine the temperature of the heater assembly 304 based on the output from the temperature sensor 308. The controller 302 therefore determines the temperature of the susceptor 132 and can determine whether the temperature meets at least one criterion. If the controller 302 determines that temperature satisfies the criterion, it causes the indicator assembly 306 to indicate that the device is ready for use. For example, the controller 302 can send a signal or instruction to the indicator assembly 306 to provide a particular indication.

In one example, the criterion is satisfied when the determined temperature is greater than or equal to the threshold temperature.

In another example, the criterion is satisfied when the determined temperature is greater than or equal to the threshold temperature, but the controller 302 does not cause the indicator assembly 306 to indicate that the device is ready for use until a predetermined period of time has passed since it was determined that the determined temperature is greater than or equal to the threshold temperature. This may be useful because, in some examples, the temperature of the susceptor 132 can fluctuate above and below the threshold temperature. The delay in causing the indicator assembly 306 to indicate the device is ready for use allows time for the heat to penetrate into the aerosol generating material. For example, although the susceptor 132 may be close to the threshold temperature, it may take at least 10 seconds for a suitable volume of aerosol to be released. It may take up to about 60 seconds for the aerosol generating material to be fully heated.

In another example, the criterion is satisfied when the determined temperature has been greater than or equal to a threshold temperature for at least a predetermined period of time. Again, this allows time for the heat to penetrate into the aerosol generating material.

Preferably the heater assembly 304 is configured so that the device is ready for use within about 30 seconds of beginning to heat the aerosol generating material.

In one example, the LEDs 214 emit light to indicate when the device 100 is ready to use. For example, one or all of the LEDs 214 may be illuminated when the device 100 is ready for use (i.e. after the criterion is satisfied). In a specific example, the number of LEDs 214 which are illuminated indicates when the device is ready for use. For example, when all of the LEDs 214 are illuminated, the device may be ready for use.

Figures 13A-E depict the outer member 202 positioned above the four LEDs 214. In this example, the LEDs 214 are sequentially illuminated as the heater assembly 304 is heated. For example, the number of illuminated LEDs may indicate how close the device is to being ready. When all four LEDs are illuminated, the device is ready for use.

Figure 13A depicts a moment in time when none of the LEDs 214 have been illuminated. At this moment in time, the criterion has not been satisfied and the controller 302 may or may not have caused the inductor coil 124 to begin generating the varying magnetic field.

Figure 13B depicts the outer member 202 a period of time after that shown in Figure 13 A. At this time, one of the LEDs has been illuminated, and light passes through a subset of the apertures 204 to illuminate one quadrant of the outer member 202. The LED may be illuminated when the temperature of the susceptor 132 has exceeded a first threshold. For example, the device may be operating in a mode where the heater assembly is to be maintained at a threshold temperature of about 250°C. The first threshold may be less than the threshold temperature. For example, the first threshold may be 220°C. Alternatively, the heater assembly may have already reached the threshold temperature, and a first threshold period of time has passed since reaching the threshold temperature. The heater assembly may still be greater than or equal to the threshold temperature, or may have dropped below the threshold temperature at least once. The first threshold period of time may be 5 seconds after the controller has determined that the temperature has reached the threshold temperature, for example.

Figure 13C depicts the outer member 202 a period of time after that shown in Figure 13B. At this time, two of the LEDs have been illuminated, and light passes through a subset of the apertures 204 to illuminate two quadrants of the outer member 202. The second LED may be illuminated when the temperature of the susceptor 132 has exceeded a second threshold. The second threshold may be greater than the first threshold and less than the threshold temperature. For example, the first threshold may be 230°C. Alternatively, the heater assembly may have already reached the threshold temperature, and a second threshold period of time has passed since reaching the threshold temperature. The heater assembly may still be greater than or equal to the threshold temperature, or may have dropped below the threshold temperature at least once. The second threshold period of time may be 10 seconds after the controller has determined that the temperature has reached the threshold temperature, for example.

Figure 13D depicts the outer member 202 a period of time after that shown in Figure 13C. At this time, three of the LEDs have been illuminated, and light passes through a subset of the apertures 204 to illuminate three quadrants of the outer member 202. The third LED may be illuminated when the temperature of the susceptor 132 has exceeded a third threshold. The third threshold may be greater than the second threshold and less than the threshold temperature. For example, the first threshold may be 240°C. Alternatively, the heater assembly may have already reached the threshold temperature, and a third threshold period of time has passed since reaching the threshold temperature. The heater assembly may still be greater than or equal to the threshold temperature, or may have dropped below the threshold temperature at least once. The third threshold period of time may be 15 seconds after the controller has determined that the temperature has reached the threshold temperature, for example.

Figure 13E depicts the outer member 202 a period of time after that shown in Figure 13D. At this time, all four of the LEDs have been illuminated, and light passes through the apertures 204 to illuminate four quadrants of the outer member 202. The fourth LED may be illuminated when the temperature of the susceptor 132 has exceeded a fourth threshold. The fourth threshold may be equal to the threshold temperature. Alternatively, the heater assembly may have already reached the threshold temperature, and a fourth threshold period of time has passed since reaching the threshold temperature. The heater assembly may still be greater than or equal to the threshold temperature, or may have dropped below the threshold temperature at least once. The fourth threshold period of time may be 20 seconds after the controller has determined that the temperature has reached the threshold temperature, for example. At this time, the criterion is satisfied, and the device is ready for use. By illuminating all four LEDs, the indictor assembly 306 has indicated that the device is ready for use.

In another example, the first threshold period of time may be between about 3 seconds and 5 seconds, the second threshold period of time may be between about 6 seconds and 10 seconds, the third threshold period of time may be between about 9 seconds and 15 seconds and the fourth threshold period of time may be between about 12 seconds and 20 seconds. The first, second, third and fourth threshold periods of time may be dependent upon the mode in which the device is operating. For example, if the device is operating in the first default mode, the first, second, third and fourth threshold periods may be longer than the respective first, second, third and fourth threshold periods for when the device is operating in the second, boost mode. This can be because the aerosol generating material heats up quicker in the second, boost mode.

In a particular example, the indicator assembly 306 may further comprise a haptic component, where the haptic component is configured to provide haptic feedback to indicate that the device has begun heating the aerosol generating material. This can be useful if none of the LEDs are illuminated at the time the inductor coil begins to generate the magnetic field. The haptic feedback may be indicative of the mode in which the device is operating.

In another example, the indicator assembly 306 may comprise a haptic component, where the haptic component is configured to provide haptic feedback to indicate that the device is ready for use. This may occur instead of, or in addition to any other types of indications. For example, the indicator assembly 306 may provide both a visual indication and haptic feedback to indicate that the device is ready for use.

In another example, the indicator assembly 306 may comprise an audible indicator, where the audible indicator is configured to emit sound to indicate that the device is ready for use. This may occur instead of, or in addition to any other types of indications. For example, the indicator assembly 306 may provide both a visual indication and emit sound to indicate that the device is ready for use.

Input Interface

As mentioned above, the controller 302 can detect an input from the input interface 112, and responsively determine a selected heating mode and cause the inductor coil 124 to generate the varying magnetic field. In the present example, the input interface 112 comprises a single button and the input interface 112 sends a signal to the controller 302 to indicate that the user has operated the input interface 112. In a specific example, the signal indicates that the user has released the button. A user can therefore press and hold the button, and the controller 302 determines the selected heating mode and causes the inductor coil 124 to generate the varying magnetic field after the button has been released.

In a specific example, the user can press and hold the button for different lengths of time, and the device is operated in a particular mode depending upon the length of time. The input received from the input interface 112 may therefore also comprise a signal indicating the length of time that the button was pressed, and the controller 302 may be configured to cause the inductor coil 124 to generate the varying magnetic field in response to receiving the signal indicating that the button has been released and in response to determining that the length of time that the button has been pressed is greater than or equal to a threshold time period. The signal indicating the length of time may be an indication of that time itself or may be a button press signal which enables the controller to determine the length of time by timing the period between the button press and button release signal. If the length of time is less than the threshold time period, the device 100 does not begin heating. Based on the length of time, the controller 302 can determine which mode has been selected. In a particular example, if the length of time is less than the threshold time period, the device 100 may display a power level of device’s power source 118. As mentioned, the device 100 may be configured to operate in a first mode or a second mode. Thus, in a particular example, if the length of time that the button has been pressed is greater than or equal to a first threshold time period and is less than a second threshold time period, the controller 302 is configured to operate the device in the first mode. If the length of time that the button has been pressed is greater than or equal to the second threshold time period, the device is configured to operate in the second mode. The first threshold time period may be 3 seconds, and the second threshold time period may be 5 seconds, for example. Thus, using a single button the user can select different modes. If the user holds down the button for longer than 3 seconds, but less than 5 seconds, the device operates in the first mode.

In a particular example, if the length of time that the button has been pressed is greater than or equal to a third threshold time period, the device is configured to operate in a settings mode. A settings mode can allow the user to configure settings of the device. The third threshold time period may be greater than the second threshold time period. In a particular example, the third threshold time period is 8 seconds. If the user holds down the button for longer than 5 seconds, but less than 8 seconds, the device operates in the second mode.

In another example, if the length of time that the button has been pressed is greater than or equal to a fourth threshold time period, but less than first time period, the device is configured to display a power level of the power source 118. The fourth threshold time period may be 1 second, for example. If the user holds down the button for longer than 1 second and less than 3 seconds, the device can display the power level. The power level may be indicated by the indicator assembly 306. For example, if the power level is between 0% and 25%, one of the four LEDs 214 may be illuminated. If the power level is between 25% and 50%, two of the LEDs 214 may be illuminated. If the power level is between 50% and 75%, three of the LEDs 214 may be illuminated. If the power level is between 75% and 100%, four of the LEDs 214 may be illuminated.

The above describes just one specific type of input interface 112. In another example the user selects the operating mode using a touchscreen. In another example, there may be one or more input interfaces. For example, to operate the device in a first mode the user may operate a first input interface and to operate the device in a second mode the user may operate a second input interface. The controller 302 may therefore be configured to cause the inductor coil to generate the varying magnetic field in response to an input received from one of the first and second input interfaces.

Indicating that the device has finished operating

As described above, the indicator assembly 306 can indicate that the device is ready for use, or to indicate that the device has begun heating the aerosol generating material. Alternatively, or additionally, the indicator assembly 306 can indicate that the device has finished operating or is about to finish operating. In certain examples, the indicator assembly 306 is configured to indicate the time left until the device finishes operating.

The device may be configured to heat the aerosol generating material for a predetermined period of time. The controller 302 may therefore cause the indicator assembly 306 to indicate that the device has finished operating or is about to finish operating within a predetermined period of time after causing the inductor coil to generate the varying magnetic field. The predetermined period of time may be about three minutes, three minutes and thirty seconds, or four minutes for example. In some examples the predetermined time depends upon the mode in which the device is operating.

In one example, the indicator assembly 306 indicates that the device has finished operating or is about to finish operating by ceasing to provide any indications. For example, while the device is operating, a visual component, such as one or more LEDs, may visually indicate that the device is operating. When the visual indication stops, the user may be informed that the device has finished operating. For example, if the one or more LEDs are illuminated while the device is operating, they may be switched off when the device has finished operating, thus providing an indication to the user. In another example, the indicator assembly 306 indicates that the device has finished operating by providing a particular indication. For example, a visual component may provide a particular indication to indicate that the device has finished operating or is about to finish operating. The visual indication may be different to a previous visual indication. For example, if one or more LEDs are illuminated while the device is operating, they may flash in a particular pattern to indicate that the device has finished operating or is about to finish operating.

In a particular example, the indicator assembly 306 may comprise a haptic component, where the haptic component is configured to provide haptic feedback to indicate that the device has finished operating or is about to finish operating. In another example, the indicator assembly 306 may comprise an audible indicator, where the audible indicator is configured to emit sound to indicate that the device has finished operating or is about to finish operating. Two or more different types of indication may be provided.

In some examples, the controller 302 may cause the indicator assembly 306 to indicate that the device has finished operating or is about to finish operating when the determined temperature satisfies a second criterion. The second criterion may be satisfied when the determined temperature is less than or equal to a second threshold temperature. The second threshold temperature may be between about 10°C and about 50°C below the temperature threshold described above. Thus, as the heater assembly 304 cools below a certain point, the indicator assembly 306 can indicate that the device has finished operating or is about to finish operating.

In some examples, the indicator assembly 306 is configured to provide an indication of the time left until the device finishes operating. For example, an indication may be provided at various points in time as the device approaches its finishing time.

In one example, a haptic component may provide haptic feedback 20 seconds from the end of the heating session, and may also provide haptic feedback 15 seconds from the end of the heating session, 10 seconds from the end of the heating session, 5 seconds from the end of the heating session and at the end of the heating session. The haptic feedback provided at each moment in time may be the same or different. For example, the feedback may become more intense or may last longer towards the end of the heating session.

In another example, the indicator assembly 306 comprises a plurality of LEDs, and the number of illuminated LEDs indicates the time left until the device finishes operating. For example, when the device is operating there may be a first number of LEDs illuminated and when the device has finished operating there may be a second number of LEDs illuminated, where the second number is less than the first number. The second number may be zero, for example. The first number may be all of the LEDs. The LEDs may therefore“count down” as the device gets closer to finishing.

In a particular example there are a plurality of LEDs, such as four LEDs, and the LEDs are sequentially switched off as the end of the heating session approaches. Figure 13E may depict the outer member 202 as the device is operating. The first and/or second inductor coils may or may not be active at this time. At this time, all four LEDs are illuminated to indicate that the user can still use the device. There may be a threshold period of time remaining until the device finishes operating. For example, there may be 20 seconds remaining until the device finishes operating.

In one example the device is said to have“finished operating” at the time the first and/or second inductor coil has ceased generating the varying magnetic field. In another example, the device is said to have“finished operating” at the time the aerosol temperature/volume is considered to fall below an acceptable level, which may be after the point at which the first and/or second inductor coil has ceased generating the varying magnetic field.

Figure 13D may depict the outer member 202 at a later time than that shown in Figure 13E. For example, there may only be 15 seconds remaining until the device finishes operating. At this time, one of the four LEDs has been switched off and light passes through a subset of the apertures 204 to illuminate three quadrants of the outer member 202.

Figure 13C may depict the outer member 202 at a later time than that shown in Figure 13D. For example, there may only be 10 seconds remaining until the device finishes operating. At this time, two of the four LEDs have been switched off and light passes through a subset of the apertures 204 to illuminate two quadrants of the outer member 202.

Figure 13B may depict the outer member 202 at a later time than that shown in Figure 13C. For example, there may only be 5 seconds remaining until the device finishes operating. At this time, three of the four LEDs have been switched off and light passes through a subset of the apertures 204 to illuminate one quadrant of the outer member 202.

Figure 13 A may depict the outer member 202 at a later time than that shown in Figure 13B. For example, the device may have finished operating. At this time, all four LEDs have been switched off and no light is visible. The indicator assembly 306 therefore indicates that the device has finished operating, while also indicating the time left until the device has finished operating.

In another example the LEDs are sequentially switched off based on the temperature of the heater assembly (i.e. as the end of the heating session approaches). For example, all four LEDs may be illuminated before the device finishes operating. When the temperature drops by a first amount, one of the four LEDs may be switched off. When the temperature drops by a second amount, another LED may be switched off. When the temperature drops by a third amount, another LED may be switched off, and when the temperature falls below by a fourth amount, all four LEDs may be switched off. The first amount may be between about 5-10°C below the operating temperature of the heater assembly (i.e. the threshold temperature). The second amount may be between about 10-20°C below the operating temperature of the heater assembly (i.e. the threshold temperature). The third amount may be between about 15-30°C below the operating temperature of the heater assembly (i.e. the threshold temperature). The fourth amount may be between about 20-40°C below the operating temperature of the heater assembly (i.e. the threshold temperature). The fourth amount may be equal to the second threshold described above.

Figure 14 is a flow diagram of a method of operating an aerosol provision device. The method comprises, at block 402, causing a heater assembly of the device to heat aerosol generating material. The method comprises, at block 404, determining a temperature of the heater assembly based on an output from a temperature sensor. The method comprises, at block 406, causing an indicator assembly of the device to indicate that the device is ready for use if the determined temperature satisfies at least one criterion.

Figure 15 is a flow diagram of another method of operating an aerosol provision device. The method comprises, at block 502, causing an inductor coil of the aerosol provision device to generate a varying magnetic field for heating a susceptor. The method comprises, at block 504, causing an indicator assembly of the aerosol provision device to indicate that the device has finished operating or is about to finish operating within a predetermined period of time after causing the inductor coil assembly to begin heating the aerosol generating material.

The above embodiments are to be understood as illustrative examples of the invention. Further embodiments of the invention are envisaged. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.