RU2784468C2 - Aerosol generating device (options), aerosol generating system, and method for control of aerosol generating device (options) - Google Patents

Abstract

FIELD: tobacco industry.

SUBSTANCE: group of inventions relates to implementation options of an aerosol generating device, an aerosol generating system, and implementation options of a method for control of an aerosol generating device. The aerosol generating device contains an air inlet, an air outlet, an airflow channel passing in the first direction between the air inlet and the air outlet, a heating element in the airflow channel for heating of aerosol forming substrate. The first temperature sensor for measurement of the first temperature is located in the first position along the airflow channel, while the first position is a position on the heating element, and the first temperature is a temperature of the heating element in the first position. The second temperature sensor is located at a distance from the first sensor in the first direction for measurement of the second temperature in the second position along the airflow channel, wherein the second position is a downstream position relatively to the heating element, and the second temperature is a temperature of the environment of the airflow channel in the specified second position. The third temperature sensor for measurement of the third temperature is located in the third position along the airflow channel, while the third position is a position located upstream relatively to the heating element, and the third temperature is a temperature of the environment of the airflow channel in the specified third position. A controller is made with the possibility of control of an operating parameter of the device based on the measured first temperature, the measured second temperature, and the measured third temperature.

EFFECT: uniform aerosol supply is provided.

15 cl, 8 dwg

Description

The present invention relates to an aerosol generating apparatus for heating an aerosol generating substrate to generate an aerosol. In particular, but not exclusively, the present invention relates to an aerosol generating device comprising a plurality of temperature sensors for controlling an operating parameter of the aerosol generating device.

In a number of hand held aerosol generating devices, a resistive heating element can be used to heat the aerosol generating substrate to generate the aerosol. The resistance heating element can be controlled by the controller. The controller may be configured to control the operation of the resistance heating element based on the temperature of the heater, which may be determined by measuring electrical resistance across the resistance heating element. This can greatly reduce the chance of damage to the resistive heating element, for example due to overheating, since the power supplied to the heating element can be limited when the measured temperature of the heater exceeds a predetermined threshold. If the resistance heating element is used to heat a supply of liquid aerosol-forming substrate, and the supply of liquid aerosol-forming substrate is reduced, the controller may detect a significant increase in the temperature of the resistance heating element. In response, the controller may prevent the generation of the resistive heating element as a result of power failure to the resistive heating element.

However, such temperature measurements cannot detect localized temperature fluctuations across the resistance heating element. This is because the electrical resistance is measured over the entire heating circuit and thus characterizes the overall temperature of the entire resistive heating element. Moreover, such temperature measurements do not indicate the temperature at locations in the device other than the heating element. For example, it is difficult to accurately obtain the temperature of an aerosol based on the electrical resistance of a resistive heating element alone.

Moreover, the temperature measurement on the resistance heating element is based on the measurement of electrical resistance when current is passed through the resistance heating element. Thus, the temperature measurement result is terminated after the resistance heating element is not operated. This can be problematic or inconvenient. For example, if the controller stops supplying power to the resistance heating element due to the temperature of the resistance heating element exceeding a threshold, the controller will not be able to continue detecting the temperature of the resistance heating element. This means that the controller will not be able to detect if the temperature of the RH has dropped below the threshold and will not re-energize the RH. This will cause the temperature of the resistance heating element to rise again. Obviously, this type of temperature measurement is carried out only with a resistive heating element. Thus, this technique cannot be used with other types of non-resistive aerosol generating device based on a heater.

The closest analogue of the claimed invention is the technical solution disclosed in the publication US 2016/235124 A1, according to which methods and systems have been developed for evaporating an extract, plant material containing organic material, etc. using convection heating through one or more manifolds, each of which is in fluid communication with a chamber section containing organic material. The manifolds may have valves and may contain temperature sensors. The controller may communicate with the temperature sensors and may control the power supplied to each heating element in response to information it processes from the temperature sensor.

It would be desirable to provide an aerosol generating device comprising a heating arrangement that reduces or overcomes at least some of these shortcomings with known devices. It would be desirable to provide an aerosol generating device that can utilize improved sensor layouts and that can implement an improved control mechanism.

According to a first aspect of the present invention, an aerosol generating device is provided, comprising: an air inlet; air outlet; an air flow channel extending in a first direction between the air inlet and the air outlet; a heating element disposed in the air flow path for heating the aerosol-forming substrate; a first temperature sensor for measuring a first temperature; and a controller configured to adjust an operating parameter of the device based on the measured first temperature; and a controller configured to adjust an operating parameter of the device based on the measured first temperature and the measured second temperature.

In some embodiments, an operating parameter may comprise a plurality of operating parameters.

The first temperature sensor and the second temperature sensor may be different types of temperature sensors. The first temperature sensor and the second temperature sensor may be the same type of temperature sensors.

In the context of this document, the term "temperature sensor" may refer to any suitable measuring means for detecting one or more signals indicative of temperature. For example, if the heating element includes a resistance heating element, a resistance heating element, and a controller for measuring electrical resistance on the electric heating element as a temperature sensor.

In the context of this document, the term "measured temperature" may refer to a direct temperature measurement or to an indirect temperature. An indirect temperature measurement may include a temperature determined by the controller based on one or more signals indicative of the temperature.

The first position and the second position may be located anywhere along the airflow path to measure localized temperatures. Said first temperature may comprise a temperature indicative of any or a combination of: ambient air at the first position, air flowing through the airflow channel at the first position, generated aerosol in the airflow channel at the first position, the heating element at the first position, and the aerosol-forming substrate supplied to the heating element in the first position. Said second temperature may comprise a temperature indicative of any or a combination of: ambient air at the second position, air flowing through the airflow channel at the second position, aerosol generated in the airflow channel at the second position, heating element at the second position, and aerosol-forming substrate supplied to the heating element in the second position. The measured temperatures may advantageously allow the controller to control one or more operating parameters of the device based on localized temperatures measured at certain known positions along the airflow path. The measured temperatures may advantageously allow the controller to determine the temperature gradient of the airflow channel along at least the first direction. The measured temperatures may advantageously allow the controller to determine localized temperature fluctuations across the heating element.

The location of each of the first and second positions may be selected to provide one or more preferred effects, as described in the embodiments described below.

The first position may be located at a distance from the heating element. The second position may be located at a distance from the heating element. In this way, it is possible to measure the temperature at one or more positions along the airflow path that are located at a distance from the heating element, for example, along a first direction along the airflow path. This provides the advantage of being able to simplify the design of the device, since the temperature sensors can be provided as separate components from the heating element. This facilitates maintenance or replacement of the heating element. This can also be advantageous when there is a need to determine the temperature of the aerosol after it has been generated on the heating element. This may be advantageous when there is a need to determine the temperature of the air source at a location before the air reaches the heating element, such as at a location where the heat of the air source is unlikely to be heavily dependent on the heat generated by the heating element. Each of the first position and the second position may be located at an equal distance from the heating element along the air flow channel.

The first position may be located immediately adjacent to the heating element, either upstream or downstream of the heating element. The second position may be located immediately adjacent to the heating element, either upstream or downstream of the heating element. This provides the advantage of being able to display said first and/or second temperature sensors just before the air reaches the heating element. This provides the advantage of being able to display said first and/or second temperature sensors immediately after the generation of the aerosol on the heating element.

In some embodiments, one of the first position and second position may be located upstream of the heating element, and the other of the first position and second position may be located downstream of the heating element. In some embodiments, both the first position and the second position may be located upstream of the heating element. In some embodiments, both the first position and the second position may be located downstream of the heating element.

The controller may be configured to control an operating parameter of the device based on the measured first temperature and the measured second temperature. In some embodiments, the controller is configured to control an operating parameter of the device based on the difference between the first temperature and the second temperature. In some embodiments, the controller is configured to control the operating parameter based on the relationship between the first temperature and the second temperature. For example, in some embodiments, a difference between the first temperature and the second temperature may advantageously indicate that one or both of the air supply and the generated aerosol flow along at least part of an air flow path that extends at least between the first position and the second position. position. More specifically, a sharp increase in one of the first or second temperatures relative to the other may indicate that such an airflow is occurring. This may be especially true if one of the first position and second position is located downstream of the heating element, and the other of the first position and second position is located upstream of the heating element. This is because a sudden drop in temperature upstream of the heating element may indicate an influx of air supply to the airflow path. A sudden rise in temperature downstream of the heating element may indicate that aerosol has been generated on the heating element and is flowing towards the air outlet. Therefore, the relative difference or relative relationship between the first temperature and the second temperature may be indicative of such events.

In some embodiments, one of the first position and second position may correspond to a position on the heating element, and the other of the first position and second position may be located at a distance from the heating element in the direction along the airflow channel. This may allow the measured heating temperature to be compared with a temperature that is measured upstream or downstream of the heating element. This may advantageously allow an airflow event to be determined. For example, a higher airflow rate may result in a lower temperature measured downstream of the heating element than would otherwise be the case if the airflow rate is lower. Thus, the controller may advantageously determine one or more airflow parameters, such as an airflow rate, based on the first and second temperatures.

In some embodiments, the controller is configured to determine an airflow event, such as any one or more of an inhalation, an exhalation, or an airflow rate, such as air volume flow, based on the measured first temperature and the measured second temperature. This provides the advantage of being able to adjust the operating parameter of the device based on a specific airflow event in addition to the specified first and second temperature temperatures. Indeed, airflow events can affect the measured first and second temperatures. By controlling the operating parameter based on both the airflow event and the first and second temperatures, the device can more accurately control said operating parameter.

In some embodiments, the heating element may comprise a plurality of heating sections. Each of the first position and the second position may be located in a respective heating portion of the heating element. Therefore, the measured first temperature may be indicative of the temperature of the first section of the heating element corresponding to the first position. The measured second temperature may indicate the temperature of the second section of the heating element corresponding to the second position. This allows the use of sensors to determine the temperatures characterizing different sections of the heating element. This provides the advantage of being able to determine the temperature gradient across the heating element. In some embodiments, the controller is configured to determine the temperature distribution across the heating element and control the operating parameter based on the determined temperature distribution. In some embodiments, each respective heating section may be independently controlled. This provides the advantage of being able to correct for any unwanted localized temperature fluctuations on the heating element. Indeed, it should be understood that in some embodiments more than two heating sections may be provided, with each respective heating section having a respective position from which the respective temperature may be measured. A plurality of heating sections with multiple positions advantageously allows a more precise temperature gradient across the heating element to be determined.

In some embodiments, the heating element may comprise a resistive heating element. In such embodiments, one of the first temperature sensor and the second temperature sensor may comprise a resistive heating element and the corresponding first or second measured temperature may be based on an electrical resistance measurement on the resistive heating element. The first temperature sensor and the second temperature sensor may be different types of temperature sensors. The first temperature sensor and the second temperature sensor may be the same type of temperature sensors.

The heating element may comprise a plastic heating element containing a plurality of metal nanoparticles arranged to receive light from a light source and generate heat via surface plasmon resonance.

As used herein, the term "surface plasmon resonance" refers to the collective resonant oscillation pattern of free electrons from metal nanoparticles and thus charge polarization at the surface of metal nanoparticles. The total resonant oscillation of the free electrons, and thus the charge polarization, is stimulated by light incident on the metal nanoparticles from a light source. Energy from vibrational electrons can be dissipated by several mechanisms, including heat. Thus, when the metal nanoparticles are irradiated with a light source, the metal nanoparticles generate heat through surface plasmon resonance.

In the context of this document, the term "metal nanoparticles" refers to metal particles having a maximum diameter of approximately 1 micrometer or less. Metal nanoparticles that generate heat through surface plasmon resonance when excited by incident light may also be known as plastic nanoparticles.

Advantageously, a plastic heating element provided for generating heat via surface plasmon resonance can provide more uniform heating of the aerosol generating substrate compared to resistive and induction heating systems. For example, the free electrons of metal nanoparticles are excited to the same extent, regardless of the angle of incidence of the incident light.

Advantageously, a plastic heating element positioned to generate heat via surface plasmon resonance can provide more localized heating compared to resistive and induction heating systems. Predominantly localized heating contributes to the heating of individual parts of the aerosol-forming substrate, or a plurality of individual aerosol-forming substrates. Advantageously, localized heating improves the efficiency of the aerosol generating device by increasing or maximizing the transfer of heat generated by the plastic heating element to the aerosol generating substrate. Predominantly localized heating can reduce or eliminate unwanted heating of other components of the aerosol generating device.

Said plasma electric heating element may be configured to receive light from an external light source and generate heat through surface plasmon resonance. The external light source may comprise ambient light. Ambient light may contain solar radiation. The ambient light may comprise at least one artificial light source located outside the aerosol generating device.

Said plasma electric heating element may receive ambient light from an ambient light source directly, or it may receive ambient light through one or more additional light transmitting elements in the device. Ambient light may be placed in the aerosol generating device through one or more windows or openings on the outer surface of the aerosol generating device. The ambient light source may function to supplement the light source of the aerosol generating device. This may be advantageous when looking to preheat the aerosol-forming substrate to an elevated temperature prior to operating the device's internal light source. This also provides the advantage of being able to reduce the amount of power required by the aerosol generating device. The aerosol generating device may include ambient light control means for controlling the amount of ambient light that the light transmitting core can receive from an ambient light source. The ambient light control means may include automatic controls such as an automatic shutter. The ambient light control may include manual controls such as a reclosable lid to cover one or more windows or openings in the device.

The aerosol generating device may include a light source, wherein the plastic heating element is configured to receive light from the light source and generate heat via surface plasmon resonance.

By using the aerosol generating device with a light source, there is an advantage of being able to enable heat generation in the plastic heating element without receiving light from an external light source. By using an aerosol generating device with a light source, the advantage of being able to provide improved illumination control of the plasma heating element is provided. Preferably, the lighting control of the plasma heating element controls the temperature to which the plasma electric heating element is heated by surface plasmon resonance.

The light source may comprise a light source configured to emit light in the visible light range of the electromagnetic spectrum. The light source may include a light source configured to emit light outside the visible light range of the electromagnetic spectrum, such as at least one of an ultraviolet light source and an infrared light source. This provides the advantage of being able to excite a wider range of nanoparticles, such as nanoparticles of various sizes or compositions.

Preferably, the light source is configured to emit light containing at least one wavelength from 380 nanometers to 700 nanometers. Preferably, the light source is configured to emit at a wavelength of about 495 nanometers to about 580 nanometers. As used herein, the term "emission wavelength" refers to the wavelength at which the light source has its maximum intensity. Advantageously, an emission peak wavelength of about 495 nanometers to about 580 nanometers can provide maximum surface plasmon resonance heating of the plasma heating element, particularly when the plurality of metal nanoparticles comprise at least one of gold, silver, platinum, and copper.

The light source of the aerosol generating device may comprise at least one of a light emitting diode (LED) and a laser.

Preferably, light emitting diodes and lasers may be of a compact size suitable for use in an aerosol generating device. The light sources of the aerosol generating device may not require a relatively large voltage drop to affect the surface plasmon resonance of the surface. For example, the light source of the aerosol generating device may comprise one or more light emitting diodes (LEDs). This can provide a safer and more economical power source to be used to power the device. In addition, there is no need to provide a physical connection between the plasma heating element and the light source. Therefore, the use of a plastic heating element can advantageously reduce the possibility of damage to the heating element during operation and maintenance. Indeed, since there is no need for a physical connection between the plasma heating element and the light source, the plasma electric element can be easily repaired or replaced. A plastic heating element may also mean that the device is less exposed to the environment, since the use of a plastic heating element can eliminate the need for exposed electrical components.

The use of a laser as a light source can provide light emission over a relatively narrow range of wavelengths. The laser may comprise at least one of a solid state laser and a semiconductor laser. The narrow wavelength range may be a range of wavelengths corresponding to the size and composition of the nanoparticles, as will be described later. This can advantageously improve efficiency, most if not all of the light emitted by the light source can be absorbed by the metal nanoparticles to generate heat via surface plasmon resonance. In addition, such a light source can be relatively robust and simple compared to other light sources.

The light emitted by the light source, such as the number of photons emitted per second, can be varied by adjusting the amplitude or frequency, or a combination of the amplitude and frequency of the emitted light. The amount of light emitted by the light source, such as the number of photons emitted per second, can be changed by emitting pulses of light.

The light source may comprise a plurality of optical radiation sources. The light sources can be the same type of light source. At least some of the light sources may be different types of light sources. The plurality of light sources may comprise any combination of the types of light sources described herein.

Advantageously, a plurality of light sources can facilitate individual selection of the heating profile generated by the aerosol generating device during use.

At least one of the light sources may be a primary light source and at least one of the light sources may be a backup light source. The aerosol generating device may be configured to emit light from one or more light sources dedicated to the light source only if one or more primary light sources are not operating.

At least one of the light sources may be configured to irradiate only a portion of the plurality of metal nanoparticles. Each of the plurality of light sources may be configured to illuminate a different portion of the plurality of metal nanoparticles.

The aerosol generating device can be configured such that a plurality of light sources irradiate different portions of the plurality of metal nanoparticles simultaneously. Preferably, irradiating different parts of a plurality of metal nanoparticles at the same time can promote uniform heating of the plasma heating element. Preferably, irradiating different parts of a plurality of metal nanoparticles at the same time can promote simultaneous heating of a plurality of individual aerosol-forming substrates.

The aerosol generating device may be configured such that a plurality of light sources irradiate different portions of the plurality of metal nanoparticles at different times. Preferably, irradiating different parts of the plurality of metal nanoparticles at different times can contribute to heating different parts of the aerosol-forming substrate at different times. By irradiating different parts of a plurality of metal nanoparticles at different times, there is the advantage of being able to promote heating of a plurality of individual aerosol-forming substrates at different times.

Preferably, the aerosol generating device further comprises an electrical power source and a controller configured to control the power supply from the electrical power source to the electrical heater.

In those embodiments in which the aerosol generating device comprises a plurality of light sources, the electrical power source may comprise a single electrical power source positioned to supply power to the plurality of light sources.

In those embodiments in which the aerosol generating device comprises a plurality of light sources, the electrical power source may comprise a plurality of electrical power sources arranged to supply electrical power to the plurality of light sources.

In embodiments where the aerosol generating device comprises a plurality of light sources, the controller may be configured to selectively energize at least some of the plurality of light sources. The controller may be configured to selectively change the electrical power supply to at least some of the plurality of light sources.

In embodiments in which a plurality of light sources are configured to irradiate different portions of a plurality of metal nanoparticles to heat a plurality of individual aerosol forming substrates, the controller may selectively energize at least some of the plurality of light sources to selectively heat at least some of many individual substrates forming an aerosol. The controller can selectively change the electrical power supply to at least some of the plurality of light sources to change the heating ratio of at least some of said plurality of individual aerosol-forming substrates.

Advantageously, by changing the relative heating of at least some of the plurality of individual aerosol generating substrates, the aerosol generating device can change the composition of the aerosol delivered to the user.

Preferably, the aerosol generating device comprises a user input device. The user input device may include at least one of a button with push buttons, a scroll wheel, a touch button, a touch screen, and a microphone. Advantageously, the user input device allows the user to control one or more aspects of the operation of the aerosol generating device. In embodiments where the aerosol generating device comprises a light source, a controller, and an electrical power source, the user input device may allow the user to activate the power source to the light source, to deactivate the power source to the light source, or both.

In those embodiments in which the controller is configured to selectively apply electrical power to at least some of the plurality of light sources, the controller is preferably configured to selectively apply electrical power to at least some of the plurality of light sources in response to user input, received by the user's input device.

In those embodiments in which the controller is configured to selectively change the electrical power supply to at least some of the plurality of light sources, the controller is preferably configured to selectively change the electrical power supply to at least some of the plurality of light sources in response to an input. user received by the user's input device.

The aerosol generating device may include one or more optical elements to facilitate transmission of light from the light source to the plastic heating element. One or more optical elements may include at least one of the following: a hole, a window, a lens, a reflector, and an optical fiber.

Preferably, at least one of the opening and the window may facilitate transmission of light from an external light source to the plastic heating element. The aerosol generating device may include a housing, with at least one of the openings and windows located on the housing.

Preferably, at least one of the lens, the reflector, and the optical fiber can concentrate or focus the light emitted from the light source onto the plastic heating element. Advantageously, concentrating or focusing light on the plastic heating element can increase the temperature to which the plasma electric heating element is heated by surface plasmon resonance.

The plurality of metal nanoparticles may contain at least one of gold, silver, platinum, copper, palladium, aluminum, chromium, titanium, rhodium, and ruthen. Many metal nanoparticles may contain at least one metal in elemental form. The plurality of metal nanoparticles may contain at least one metal in a metal compound. The metal compound may contain at least one metal nitride.

Preferably, the plurality of metal nanoparticles contains at least one of gold, silver, platinum and copper. Advantageously, gold, silver, platinum and copper nanoparticles can exhibit strong surface plasmon resonance when irradiated with visible light.

A plurality of metal nanoparticles may contain a single metal. The plurality of metal nanoparticles may contain a mixture of different metals.

The plurality of metal nanoparticles may comprise a plurality of first nanoparticles containing a first metal and a plurality of second nanoparticles containing a second metal.

At least some of the many metal nanoparticles may contain a mixture of two or more metals. At least some of the many metal nanoparticles may contain a metal alloy. At least some of the plurality of metal nanoparticles may comprise a core-shell configuration, with the core containing a first metal and the shell containing a second metal.

In embodiments where the aerosol generating device comprises a light source, preferably the plurality of metal nanoparticles comprise a number average maximum diameter that is less than or equal to the emission wavelength of the light source.

The plurality of metal nanoparticles may have a number average maximum diameter of less than about 700 nanometers, preferably less than about 600 nanometers, preferably less than about 500 nanometers, preferably less than about 400 nanometers, preferably less than about 300 nanometers, preferably less than about 200 nanometers, preferably less than about 150 nanometers, preferably less than about 100 nanometers.

The plastic heating element may be formed from a plurality of metal nanoparticles.

Said plastic heating element may comprise a substrate and a coating layer located on at least a portion of the substrate, the coating layer containing a plurality of metal nanoparticles. Advantageously, the substrate may be formed from a material selected for the desired mechanical properties. Advantageously, the coating layer may be formed to optimize surface plasmon resonance from a plurality of metal nanoparticles when the coating layer is exposed to light from a light source.

The substrate may be made from any suitable material. The substrate may contain metal. The substrate may contain a polymeric material. The substrate may contain ceramics.

The substrate may be electrically conductive. The substrate may be electrically insulating.

The nanoparticles may be provided on the substrate using any suitable process. The metal nanoparticles can be deposited onto a substrate using a physical vapor deposition process.

The plastic heating element may contain a plurality of distinct regions of metal nanoparticles, with the plurality of distinct regions spaced apart from each other. Advantageously, the plurality of distinct regions of the metal nanoparticles can contribute to the heating of the plurality of discrete portions of the aerosol forming substrate. Advantageously, a plurality of individual regions of the metal nanoparticles can contribute to the heating of a plurality of individual aerosol-forming substrates.

The aerosol generating device may include a light source configured to irradiate a plurality of discrete areas of the metal nanoparticles. The aerosol generating device may comprise a plurality of light sources for irradiating a plurality of distinct regions of the metal nanoparticles. Each of the plurality of light sources may be configured to irradiate only one of the individual regions of the metal nanoparticles.

The plastic heating element may include a first surface configured to receive light from a light source and generate heat through surface plasmon resonance from a plurality of metal nanoparticles. The first surface may contain a plurality of surface features that define a three-dimensional shape. The first surface may include at least one of a plurality of protrusions and a plurality of depressions. The first surface may have a wave-like shape.

Advantageously, the first surface containing a plurality of surface features may increase the surface area of the first surface. Advantageously, increasing the surface area of the first surface can increase the heating of the plurality of metal nanoparticles by surface plasmon resonance when light is on the first surface.

In embodiments where the plastic heating element comprises a substrate and a coating layer, the first surface of the substrate may define a plurality of surface features, with the coating layer provided on the first surface of the substrate to form the first surface of the plasma heating element.

Said plastic heating element may comprise a second surface configured to transfer heat to the aerosol-forming substrate during use. The second surface may be located on the opposite side from the plastic heating element to the first surface. In embodiments where the plasma heating element comprises a substrate and a coating layer, preferably the substrate comprises a first surface on which a coating layer is provided to form a first surface of the plasma heating element and a second surface forming a second surface of the plasma heating element. Preferably, the substrate contains a thermally conductive material to facilitate heat transfer from the coating layer to the second surface of the plastic heating element.

In embodiments in which the heating element comprises a resistive heating element and a plastic heating element, said plurality of metal nanoparticles may form a resistive heating element.

In embodiments in which the plastic heating element comprises a substrate and a coating layer, at least one layer of the substrate and the coating layer may form a resistive heating element. The substrate may comprise an electrically resistive material. The electrically resistive material may comprise at least one of the following: an electrically resistive metal and an electrically resistive ceramic. The substrate may be formed from an electrically resistive material. The substrate may comprise a woven material, wherein the plurality of filaments of the electrically resistive material form at least a portion of the woven material.

In those embodiments in which the aerosol generating device comprises an electrical power source and a controller, the controller is preferably configured to supply electrical power from the electrical power source to the resistance heating element.

The aerosol generating device may be configured to generate heat using a resistive heating element in addition to generating heat through surface plasmon resonance from a plurality of metal nanoparticles. An aerosol generating device may be configured to generate heat using a resistive heating element as an alternative to generating heat via surface plasmon resonance from a plurality of metal nanoparticles.

The aerosol generating device may be configured to generate heat using a resistive heating element as a backup to generate heat through surface plasmon resonance from a plurality of metal nanoparticles. For example, the aerosol generating device may be configured to generate heat using a resistive heating element in the event of insufficient surface plasmon resonance heating of a plurality of metal nanoparticles.

The aerosol generating device may be configured to generate heat using a resistive heating element at the beginning of the heating cycle. In other words, the resistance heating element may be used to generate heat to raise the temperature of the heating element to an initial operating temperature. The aerosol generating device may be configured to reduce or terminate power to the resistance heating element when the temperature of the heating element reaches an initial operating temperature.

A device operating parameter may affect the operation of one or more device components. An operating parameter may contain one or more process variables that affect the operation of one or more device components. Preferably, the one or more components comprise one or more components used by the aerosol generating device, such as a heating element, or a power supply capable of supplying power directly or indirectly to the heating element. For example, in some embodiments, the implementation of the operating parameter may contain the temperature of the heating element. The operating parameter may comprise the temperature profile of the heating element, such as the outlet temperature over time. The temperature or temperature profile may be controlled by a controller controlling the power supplied to the heating element from a power source. Power can be supplied directly to the heating element. Power may be supplied indirectly to the heating element, for example, by supplying electrical power to one or more light sources that are positioned to provide light to the plasma heating surface of the heating element. The controller may be configured to control the outlet temperature of at least a portion of the heating element based on the measured first temperature and the measured second temperature. In the above embodiments where the first and second locations are located on different heating sections along the heating element, the controller may be configured to independently control an operating parameter associated with each of the heating sections based on the respective first and second sensed temperatures. For example, the controller may be configured to determine the temperature distribution across the plurality of heating sections and may separately control the power supplied to each of the plurality of heating sections based on the determined temperature distribution. In this way, the heat generated by the heating element can be more precisely controlled. Controlling the power supplied to said plurality of heating sections can be achieved by controlling the supply of electrical power to one or more of a plurality of light sources that are arranged to provide power to each of the respective heating element heating sections. For example, if the first light source is positioned to provide light to the first heating section and the second light source is positioned to provide light to the second heating section, the controller may be configured to increase the amount of light emitted by the second light source relative to the amount of light emitted by the first light source. if it has been determined that the measured temperature corresponding to the second section of the heating element is lower than the measured temperature corresponding to the first section of the heating element.

In some embodiments, the controller may be configured to activate or otherwise control the amount of heat dissipated by the heating element when airflow is detected. In some embodiments, the implementation of the controller may be configured to control the operating parameter based on a certain air flow. For example, the controller may be configured to control the temperature of the heating element based on the volumetric airflow rate through the airflow path.

In some embodiments, an aerosol generating device may comprise: a liquid storage portion containing an aerosol generating substrate; and a pump for pumping the aerosol-forming substrate from the liquid storage portion to the heating element; wherein the operating parameter of the device comprises a flow rate of the aerosol-forming substrate from the liquid storage portion to the heating element, wherein the controller is configured to control the flow rate of the aerosol-forming substrate based on the measured first temperature and the measured second temperature. In some embodiments, the controller may be configured to control a pump to dispense a controlled volume of liquid substrate based on a first temperature and a second temperature. In some embodiments, the controller may be configured to control a pump to dispense a controlled volume of liquid substrate based on an airflow event, such as volumetric airflow through an airflow channel. The pump may be configured to dispense a controlled volume of liquid substrate based on the amount of airflow passing through the airflow channel. In some embodiments, the liquid storage portion may be a replaceable cartridge. For example, the aerosol generating device may include a connector for connecting to a connector, such as a Luer fitting, of the cartridge.

In some embodiments, said first position is a position on the heating element and said first temperature is the temperature of the heating element at the first position and said second position is a position downstream of the heating element and said second temperature is the temperature environment of the airflow channel in the specified second position. In some embodiments, the device comprises a third temperature sensor for measuring a third temperature at a third position along the airflow path, said third position being a position upstream of the heating element, and said third temperature being the ambient temperature of the airflow path. at said third location, and the controller is configured to control an operating parameter of the device based on the first temperature, the second temperature, and the third temperature. This may advantageously allow the controller to determine a more accurate airflow rate by taking heater temperature into account when comparing relative temperatures or temperature changes that are measured upstream and downstream of the heating element.

In some embodiments, the temperature sensors may be temperature sensors on a chip. Temperature sensors can be planar. Temperature sensors can be built into the surface of the heating element. Thus, the use of such on-chip temperature sensors can advantageously prevent excessive interruption of the air flowing in the air flow path. In some embodiments, the surface of such on-chip temperature sensors may be coated with nanoparticles to effect surface plasmon resonance. Advantageously, the inclusion of such on-chip temperature sensors does not reduce the heating area available for surface plasmon resonance.

The power supply is preferably an electrical power supply, which may comprise a DC power supply. The electrical power supply may include at least one battery. The at least one battery may include a rechargeable lithium ion battery. The electrical power supply may contain another form of charge storage device, such as a capacitor. The electrical power supply may need to be recharged. The electrical power supply may have a capacity that allows sufficient energy to be stored for one or more uses of the aerosol generating device. For example, the electrical power supply may have sufficient capacity to continuously generate an aerosol for a period of approximately six minutes, which is typical of the time required to smoke a conventional cigarette, or for a period of multiples of six minutes. In another example, the electrical power supply may have sufficient capacity to allow for a predetermined number of puffs or individual activations.

In embodiments where the aerosol generating device comprises a plastic heating element and a light source, the controller may be configured to initiate electrical power supply from the electrical power source to the light source at the beginning of the heating cycle. The controller may be configured to terminate the power supply from the electrical power source to the light source at the end of the heating cycle.

The controller may be configured to supply a continuous power supply from an electrical power source to the light source.

The controller may be configured to provide an intermittent power supply from an electrical power source to the light source. The controller may be configured to supply a pulsed power supply from an electrical power source to the light source.

Advantageously, switching power supply to the light source can help control the total output from the light source over a period of time. Preferably, controlling the total output from the light source over a period of time can help control the temperature to which the plasma heating element is heated by surface plasmon resonance.

Advantageously, a switching power supply to a light source can increase the thermal relaxation of free electrons excited by surface plasmon resonance compared to other relaxation processes such as oxidation and mechanical relaxation. Therefore, a predominantly switching power supply to the light source can increase the heating of the plasma heating element. Preferably, the controller is configured to pulse power from an electrical power source to the light source such that the time between successive light pulses from the light source is approximately 1 picosecond or less. In other words, the time between the end of each light pulse from the light source and the beginning of the next light pulse from the light source is equal to or less than about 1 picosecond.

The controller may be configured to change the supply of electrical power from the electrical power source to the light source. In those embodiments in which the controller is configured to provide a pulsed power supply to the light source, the controller may be configured to change the duty cycle of the pulsed power supply. The controller may be configured to change the pulse width and/or fill period.

The aerosol-forming substrate may be an aerosol-forming liquid substrate. The aerosol generating device may include a liquid moving element configured to transport the aerosol generating liquid substrate out of the storage portion and towards the heating element. The fluid transport element may include a capillary wick.

The aerosol-forming liquid substrate may contain water.

The aerosol-forming liquid substrate may contain an aerosol-forming agent. Suitable aerosol forming agents are well known in the art and include, but are not limited to: polyhydric alcohols such as triethylene glycol, 1,3-butanediol, and glycerol; polyhydric alcohol esters such as glycerol mono-, di-, or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Preferred aerosol forming agents are polyhydric alcohols or mixtures thereof, such as triethylene glycol, 1,3-butanediol, and most preferably glycerol or polyethylene glycol.

The aerosol-forming liquid substrate may contain at least one of nicotine or a tobacco product. Additionally or alternatively, the aerosol-forming liquid substrate may contain another target compound for delivery to the user. In embodiments in which the aerosol generating liquid substrate contains nicotine, nicotine may be contained in the aerosol generating liquid substrate along with the aerosol generating agent.

The aerosol generating device may comprise a first aerosol generating substrate and a second aerosol generating substrate. Preferably, the heating element is configured to heat both the first aerosol-forming substrate and the second aerosol-forming substrate.

According to a second aspect of the present invention, a liquid storage cartridge is provided, comprising a connector for connecting the liquid storage cartridge to an aerosol generating device, wherein the liquid storage cartridge contains an aerosol generating liquid substrate and is compressible when the aerosol generating substrate is depleted. Loss of aerosol-forming substrate may not cause negative pressure in the liquid storage cartridge. This provides the advantage of being able to prevent air from entering the inside of the cartridge. In some embodiments, the connector is a Luer fitting.

According to a third aspect of the present invention, an aerosol generating system is provided, comprising an aerosol generating device according to the first and second aspects of the present invention, and an aerosol generating article comprising an aerosol generating substrate. An aerosol generating article may comprise a liquid storage cartridge containing an aerosol generating substrate.

In the context of this document, "aerosol generating device" refers to a device that can interact with an aerosol generating substrate to generate an aerosol.

In the context of this document, the term "aerosol-forming substrate" refers to a substrate capable of releasing volatile compounds that can form an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate.

The aerosol generating substrate may be part of the aerosol generating article. The aerosol forming substrate may have any suitable configuration and may contain any of the features described in more detail below.

In the context of this document, the term "aerosol generating system" refers to a combination of an aerosol generating device and one or more aerosol generating articles for use with the device. The aerosol generating system may include additional components such as a charger for recharging the built-in power supply in the electrically operated or electrical aerosol generating device.

According to a fourth aspect of the present invention, there is provided a method for controlling an aerosol generating device, said aerosol generating device comprising a heating element in an air flow path extending in a first direction, the method comprising the steps of: measuring a first temperature at a first position along the air flow path ; measuring a second temperature at a second position along the air flow passage; and controlling an operating parameter of the device based on the measured first temperature and the measured second temperature, based on the measured first temperature and the measured second temperature.

According to a fifth aspect of the present invention, an aerosol generating device is provided, comprising: an air inlet; air outlet; an air flow channel extending in a first direction between the air inlet and the air outlet; a heating element in the air flow path for heating the aerosol-generating substrate; a first temperature sensor for measuring a first temperature at a first position along the air flow passage; and a controller configured to control an operating parameter of the device based on at least the measured first temperature.

Features described in relation to one aspect may be equally applicable to other aspects of the present invention.

Embodiments of the present invention will now be described solely as examples with reference to the accompanying drawings, in which:

in fig. 1 is a perspective view of an aerosol generating system according to an embodiment of the present invention;

in fig. 2a is an exploded perspective view of the heating assembly shown in FIG. one;

in fig. 2b is a perspective view of the heating unit of FIG. 2b;

fig. 2c is a sectional view of the heating unit of FIG. 2a and 2b.

in fig. 3 is a sectional view of a heating unit according to an embodiment of the present invention;

in fig. 4 is a perspective view of a heating element of an aerosol generating system according to embodiments of the present invention; and

in fig. 5a is a schematic representation of heat dissipation on the heating element shown in FIG. 4, in a first state in which there is substantially no air flow through the heating element; and

in fig. 5b is a schematic representation of heat dissipation on the heating element shown in FIG. 4 in a second state in which the air supply is drawn into the aerosol generating device through the heating element.

In FIG. 1 shows an aerosol generating system 10 comprising an aerosol generating device 20 and a liquid storage portion 100 enclosing a liquid aerosol generating substrate for use with the aerosol generating device 20.

The aerosol generating device 20 includes a housing configured to accommodate a liquid storage portion 100, such as in a storage compartment. The liquid storage portion 100 in the illustrated example of FIG. 1 is a replaceable cartridge containing an aerosol-forming substrate, such as a liquid aerosol-forming substrate. The replaceable cartridge is operable to be connected to the metering unit 60 of the aerosol generating device 20 via a sealed connection 62, such as a Luer connection, and a tube 64. The metering unit 60, which in the illustrated examples includes a pump, provides controlled delivery of an aerosol generating liquid substrate, to the heating node 30, where the liquid substrate is heated to steam. As the user puffs on the mouthpiece 66, the air supply is drawn into the aerosol generating device 20 through the air inlet 50. An air source at room temperature condenses the vapor to form a stream of generated aerosol. The mouthpiece 66 defines an air outlet 52. As the user puffs on the mouthpiece 66, the generated aerosol can exit the device and enter the user's mouth. Thus, the air supply and the generated aerosol flow in the air flow path formed between the air inlet 50 and the air outlet 52.

The heating assembly 30 in the illustrated embodiment includes a plastic heating element. Said plasma electric heating element generates heat through surface plasmon resonance (SPR). Plastic heating elements typically contain a plurality of metal nanoparticles and are based on excitation of the metal nanoparticles with light, such as visible light from a light source 40 . The impact of incident light leads to the total vibrational deformation of free electrons of metal nanoparticles and charge polarization on the surface of metal nanoparticles. To weaken their original state, the nanoparticles release this excess energy in the form of heat. Typically, the nanoparticles used in plasmoidal heaters have particle sizes that are equal to or less than the wavelength of visible light.

The aerosol generating device 20 comprises an electrical power source 12, such as a rechargeable lithium ion battery. The power supply 12 includes a charging port 16 for charging a rechargeable battery. Device 10 further comprises a controller 14 communicatively coupled to one or more light sources. In the illustrated embodiment, the light sources comprise a light-emitting diode (LED) 40. The controller is also communicatively connected to the power source 12 and the user interface 26. In this embodiment, the user interface 26 includes a mechanical button. When the user interface 26 is activated, the controller controls the power supply from the power supply 12 to the light source 40 to heat the heating element 30 to the desired operating temperature. In some embodiments, the controller controls the power supplied to the light source 40 to provide a heating profile, such as a temperature profile, of the heating element during the period of time that the device 20 is in use.

In FIG. 2a-2c show an example of a heating unit 30. In the depicted embodiment, the heating unit 30 includes a heating element 32. The light source 40 is positioned to emit light towards the heating element 32 when the light source 40 receives a power supply. The heater assembly 30 includes an aerosol generating chamber 38 between the light source 40 and the heating assembly 30. The aerosol generating chamber 38 provides a volume in which the liquid substrate can evaporate to form an aerosol with an incoming air source. The aerosol-generating chamber 38 forms part of the air passage between the air inlet 50 and the air outlet 52. The air flow channel extends along the first direction between the air inlet 50 and the air outlet 52. The first direction coincides with or substantially parallel to the longitudinal axis of the device 20.

The heating element 32 in the illustrated embodiments comprises a flat element containing a silicon-based material, such as quartz, which is capable of maintaining its mechanical strength at elevated temperature. The heating element 32 includes a heating surface 34 extending through at least a portion of the heating element 32 within the aerosol generating chamber 38 to heat and vaporize an incoming dose of liquid substrate. The heating surface 34 contains a plurality of metal nanoparticles for surface plasmon resonance.

In this particular example, the heating surface 34 is coated with a layer of silver nanoparticles with an average diameter of 100 nm, although other sizes of nanoparticles are also applicable. Alternatively, other metal colloid or nanoparticles can be used, such as gold or platinum nanoparticles. A mixture of metal nanoparticles may also be applied to the heating surface 34 to conduct plastic heating, such as a mixture of gold and silver nanoparticles. Since the amount of nanoparticles is a critical factor in controlling the power output in a plastic heater, it is preferable to provide as many nanoparticles as possible on a given heating surface. Therefore, in order to increase the density of the nanoparticles, and thus increase the heat generated by the surface plasmon resonance, the heating surface, in some embodiments, contains multiple layers of nanoparticles to create a total amount of available metal nanoparticles.

The illustrated light source 40 includes a light emitting diode (LED). More specifically, the light source 40 includes an array of LEDs, each for independent control of the controller 14. For example, a plurality of LEDs may emit light sequentially, at different intensities, or at different wavelengths. This provides a change in temperature rise over the entire heating surface. This is particularly useful as it also provides selective, localized heating of the heating surface 34.

The light source 40 is positioned in alignment with the heating surface 34 of the heating element 32. For example, the light source 40 is superimposed but spaced away from the heating surface 34. This arrangement provides the metal nanoparticles with maximum exposure to the incident light emitted by the LED array. For example, a plurality of LEDs in an LED array may emit light sequentially, at different intensities, or at different wavelengths. This provides a change in temperature on the heating surface. This is advantageous as it also provides selective localized heating. This can be used to correct local temperature fluctuations on the heating surface 34 of the heating element 32. In use, the light source 40 is configured such that the heating surface 34 is heated to a temperature of 200 to 350 degrees Celsius.

As illustrated in FIG. 2c, the device 20 includes a lens 44 for influencing refraction and focusing light emitted by a group of LEDs towards a heating surface 34. A lens 44 is positioned between the LED light source 40 and the heating surface 34. For example, each of the LEDs in the LED array 40 includes a lens , formed as a whole with the LED. Additional lens 44 is located above the array of LEDs. The reflected light may be focused or dispersed by the lens 44 to control how much light is transmitted to the heating surface 34 or portions thereof.

In some other embodiments, alternate light sources may be used as the light source. For example, the light source may include a laser diode. The laser diode provides maximum excitation of a specific type of nanoparticles. In some embodiments, lens 36 of heater assembly 30 may be coupled to an ambient light path (not shown) external to body 12 of device 20 to capture and transmit light from an external light source, such as natural daylight. or ambient light, in the direction of the heating surface 34 of the heating element 32. In such cases, the external light received at the lens 44 may have a lower intensity compared to the artificial light source 38. However, an external light source can be used to preheat the aerosol-forming substrate 102 to an elevated temperature above ambient temperature, thus the power consumption of the artificial light source 38 can be reduced accordingly.

The heating assembly 30 includes a fluid passage 36 for supplying a liquid substrate to the heating surface 34. The figures show a single fluid passage 36 having an outlet adjacent the heating surface 34. A plurality of fluid passages may also be provided. The use of a plurality of fluid channels can advantageously consume and supply the liquid substrate across the width of the heating surface 34.

A capillary fitting 65 is provided to connect tubing 64 and fluid channel 36. Capillary fitting 65 also forms a distributor for distributing a dose of liquid substrate evenly among a plurality of liquid channels 36.

The heating unit 30 further includes an air inlet 50 for being drawn into the air source. Said air inlet 50 is in fluid communication with the air flow channel. As the user puffs on the mouthpiece 66, a supply of air is drawn into the aerosol generating chamber 38 from the environment surrounding the device 20 through the air inlet 50. When the heating element 32 is activated, the air drawn into the device is relatively cold compared to the ambient air within the device near the heater. This relatively cold air source condenses at least a portion of the vaporized aerosol-generating substrate in the aerosol generation chamber 38, thereby forming a stream of generated aerosol.

The heat generated on the heating surface 34 by surface plasmon resonance propagates to radiation through the aerosol generating chamber 38. This may heat up the LED light source 40 . Preferably, the flow of air through the aerosol generating chamber 38 through the air inlet 50 cools the light source 40, thus protecting it from overheating.

In some embodiments, heating surface 34 may comprise a plurality of separate heating sections. This makes it possible to more accurately determine the temperature of the surface 34 from the heating surface. In some embodiments, each heating section may have a different density of metal nanoparticles or a different number of layers of nanoparticles. This provides a change in temperature rise in different areas of heating, when all heating sections are exposed to a uniform light source. This is advantageous because it provides selective localized heating. For example, since the upstream heating sections located near the air inlet 50 are more affected by relatively cold air entry, these heating sections may contain relatively more nanoparticles compared to the proximal heating sections proximate the air outlet 52. air and mouthpiece 66. In some cases, the plurality of heating sections also allow selective heating of the aerosol forming substrate, thus allowing liquid substrates and flavoring compositions to be heated across the substrate to different temperatures.

The liquid storage part 100 used in the illustrated example is a replaceable cartridge. The replaceable cartridge 100 includes flexible sidewalls and is compressible when the liquid aerosol-forming substrate is used up. Loss of liquid aerosol-forming substrate in cartridge 100 does not cause negative pressure in the liquid storage portion. Therefore, displacement of the aerosol-forming liquid substrate does not cause air bubbles to re-enter the cartridge 100. Thus, the possibility of intermittent liquid substrate delivery caused by such air bubbles and pump cavitation is reduced.

In FIG. 3 is a sectional view of yet another embodiment of the present invention. The aerosol generating chamber 38b may include a tubular body 22b. In this example, the aerosol generating device 20b contains the same components as the device 20 as shown in FIG. 2a-2c. The light source 40b and the lens 44b are formed on the outside of the tubular body 22b. Lens 44b is configured to refract and focus light emitted by light source 40b onto planar heating surface 34b on heating element 32b. A portion of the tubular body 22b includes a support 24b to provide a clear platform for supporting a heating element 32b, such as a planar heating element 32b.

In FIG. 4 is a perspective view showing part of the heating unit 30. The heating unit 30 includes a heating element 32 and a plurality of temperature sensors 80, 82, 84. In the illustrated embodiment, the plurality of temperature sensors include a heating element sensor 80 on the heating surface 34 for measuring the temperature at the heating element. The plurality of temperature sensors 80, 82, 84 further comprise an upstream sensor 82 and a downstream sensor 84 respectively located upstream and downstream of the heating surface 34. In this example, the upstream sensor 82 and the downstream sensor 84 flow are located at an equal distance from the heating surface 34 at an equal distance from it to measure the temperature. Temperatures sensed by upstream sensor 82 and downstream sensor 84 may have an air temperature equal to or greater than the position of the respective sensors 82, 84, or a generated aerosol temperature located at or near the position of the respective sensors 82, 84. In the context of this document, the phrase "upstream" refers to a location closer to the air inlet 50 than to the air outlet 52. As used herein, the phrase "downstream" refers to a position closer to the air outlet 52 than the air inlet 50.

Temperature sensors 80, 82, 84 may be temperature sensors on a chip. Such on-chip temperature sensors are generally planar and can be easily incorporated into the heating element 32. Thus, the use of these on-chip temperature sensors does not unnecessarily interrupt the air flow in the aerosol generating chamber 38. In addition, the surface of such on-chip temperature sensors can be coated with metal nanoparticles. This is especially useful for the heater element sensor 80 because its inclusion does not reduce the amount of heating surface 34 available for plastic heating.

The controller 14 is configured to control the operating parameter of the device 20 by at least two temperatures along the airflow channel. The temperature of the heating element 32 as measured by the heating element sensor 80 may be sufficient for the controller 14 to enable feedback control on the power supply 40 . More specifically, the controller 14 may be configured to control the intensity or speed of the pulsation, or combination of intensity and pulsation, of the light emitted by the light source 40 based on the measured temperature of the heater. This allows the temperature of the heating element 32 to be controlled to maintain the desired temperature or within the desired temperature range. The controller can apply traditional temperature control based on the measured heater temperature.

The use of a plurality of temperature sensors 80, 82, 84 provides additional operational information such as a temperature gradient across the heating surface 34, a temperature gradient across the aerosol generating chamber 38, or an airflow event to be captured. Based on this, new control mechanisms can be applied. For example, temperatures measured at various locations along the aerosol generating chamber 38 by temperature sensors 80, 82, 84 can be used to determine an airflow event such as inhalation, exhalation, or an airflow rate such as the volumetric flow rate of air supplied by the airflow. . In FIG. 5a shows the air temperature profile along the aerosol generating chamber 38 when the air flow is not passing through the air flow channel. The heating surface 34 is supplied by incident light without the user puffing on the mouthpiece. For example, the user may interact with the user interface 26 to initiate preheating of the heating element 32. The volume of fluffy air around the heating surface 34 is gradually heated by the heating surface 34, primarily due to natural convection. As a result, the air temperature, as shown in FIG. 5a gradually decreases with increasing distance from the heating surface 34. As shown in FIG. 5a, the temperature distribution of the underlying air around the activated heating element 32 is substantially symmetrical. Because the temperature is the same in both the upstream and downstream directions, upstream sensor 82 and downstream sensor 84 detect similar air temperatures at each end of heating surface 34. This temperature reading indicates no airflow in the chamber and thus the controller can cut off the power supply to the light source to prevent overheating on the heating surface 34 as well as save energy.

In FIG. 5b shows another temperature profile along the aerosol generating chamber 38 when the user takes a puff on the mouthpiece. In this example, air supply 90 flows from upstream sensor 82 to downstream sensor 84. The ambient air source displaces fusible air on the heater surface, thus causing a decrease in air temperature as measured by upstream sensor 82. . On the other hand, the downstream sensor 84 will detect an increase in air temperature as the heated air and generated aerosol are carried towards the downstream sensor 84 by the compression force. The relative air temperature changes detected by the upstream sensor 82 and the downstream sensor 84 are related to the flow rate of the air supply 90. For example, higher airflow increases the temperature difference detected by upstream sensor 82 and downstream sensor 84. As a result, airflow 90 can be determined based on two temperatures, such as due to a difference or ratio between the two temperatures, measured sensors 82, 84 spaced from each other. This measurement can be used in conjunction with the heater element sensor 80 to provide a more accurate determination of the temperature gradient across the heating surface 34 of the heater element 32 in the aerosol generating chamber 38.

The heater temperature measured by the heater element sensor 80, in combination with only one of the upstream and downstream sensors 82, 84, can be used in determining the air flow rate based on enthalpy. The downstream temperature measured by the downstream sensor 84 may be compared with the temperature of the heating element 32 to estimate the volume of air flowing between the heating element sensor 80 and the downstream temperature sensor 84. For example, for a given heating element temperature, a relatively high airflow rate will result in a relatively low downstream temperature as measured by downstream sensor 84, as the heating element provides heat in the direction of the larger volume of incoming air. Additional consideration of the temperature of the heating element 32 improves the accuracy of the calculation of the air flow rate.

Controller 14 may refer to information stored in a memory device for processing one or more temperatures sensed by sensors 80, 82, 84, or for determining how to control a specified operating parameter based on one or more temperatures, or both. . The memory may be a permanent computer-readable medium. The memory may be part of the aerosol generating device, or may be remote from the device, such as a memory storage device on a cloud server. The information may include at least one lookup table. The information may contain at least one algorithm. For example, a lookup table stored in memory may provide an empirical airflow rate corresponding to different temperature measurements. The lookup table can also provide empirical airflow rates corresponding to different temperature measurements and distances from the temperature sensors.

The controller is configured to control the operating parameter of the device 20 directly on the measured temperature from a plurality of temperature sensors 80, 82, 84. The controller may be configured to control the operating parameter of the device 20 indirectly based on the measured temperature from a plurality of temperature sensors 80, 82, 84. For example, the controller may be configured to control an operating parameter of the device 20 based on an airflow event, such as an airflow rate determined based on the measured temperatures described above. The operating parameter may comprise a plurality of operating parameters. The operating parameter may comprise one or more of the following: the temperature of the heating element 32, the temperature profile of the heating element 32, such as the outlet temperature over time, the power supplied directly or indirectly to the heating element 32, the flow rate of the aerosol-forming liquid substrate from of the liquid storage portion 100 to the heating surface 34 and the dosage volume of the aerosol-forming liquid substrate supplied to the heating surface 34. As described above, the temperature or temperature profile of the heating surface 34 may be controlled by the controller 14 controlling the power supplied from the power supply 12 to the heating element 32 from the power source to the heating element 32. Power can be supplied directly to the heating element 32. Power can be supplied indirectly to the heating element 32, for example, by supplying electrical power source 40 light, which is configured to supply light to the plasma heating surface 34 of the heating element 32.

In an exemplary embodiment, the aerosol generating device 20 is configured to control the flow rate of the aerosol generating liquid substrate from the liquid storage portion 100 to the heating surface 34 as follows. First, the user activates the light source 40 by pressing the user interface mechanical button 26. Light is emitted by the light source 40 and falls incident on the metal nanoparticles of the heating surface 34 to initiate surface plasmon resonance. Since the nanoparticles on the heating surface 34 repeatedly undergo surface plasmon resonance followed by thermal relaxation, the temperature of the heating surface 34 increases to the desired operating temperature. Typically, the heating surface 34 is heated to an operating temperature in the range of 200 to 350 degrees Celsius.

The controller 14 may determine whether the temperature of the heating surface 34 of the heating element 32 reaches a first threshold temperature, such as a desired operating temperature. When the heating surface 34 reaches the first threshold temperature, the controller 14 activates the pump of the dosing unit 60 to supply the heating surface 34 with a dose of the aerosol-forming liquid substrate after the desired operating temperature has been reached. The controller 14 may terminate or reduce the power supply to the light source when the heater temperature exceeds the second threshold temperature. The second threshold temperature may be relatively higher than the first threshold temperature and may be within a predetermined temperature limit. Therefore, the controller 14 can prevent the heating element from overheating.

The controller 14 may analyze a relationship, such as relative differences or ratios, between the temperature measurements obtained by the plurality of sensors 80, 82, 84. Based on this analysis, the controller 14 then determines the instantaneous airflow rate through the aerosol generation chamber 38.

Based on the detected airflow, the controller 14 determines whether the temperature of the heating surface 34 needs to be adjusted. For example, when a user takes a puff through the mouthpiece 66, ambient air is drawn through the air inlet 50 into the aerosol generating chamber 38. This incoming air initially exerts a cooling effect on at least a portion of the heating surface 34 of the heating element 32. Therefore, upon detecting inhalation, the controller 14 may determine that a temperature adjustment is required, such as raising the temperature on the heating surface 34. When the controller determines that an adjustment is required temperature, the controller 14 determines the required amount of power to be supplied to the light source 40 to perform a certain temperature control. Therefore, the controller 14 can adjust the temperature of the heating surface 34 to correct for cooling caused by the incoming air source when the user takes a puff on the mouthpiece 66. This helps to maintain a stable operating temperature on the heating surface 34 of the heating element 32 while the user operates the device. In this way, it is possible to prevent overheating of the heating element 32. Overheating on the heating surface 34 due to fluctuations in the incoming air can also be prevented.

In some embodiments, based on the determined airflow rate, the controller may also determine the amount of aerosol-forming substrate required to be dispensed onto the heating surface 34. The controller 14 then controls the operation of the pump of the metering unit 60 to control the rate of delivery of the liquid aerosol-forming substrate to the heating surface. surface 34. More specifically, the amount of liquid substrate that may be introduced onto the heating surface 34 may be proportional to the airflow rate. This can provide a constant concentration of aerosol with every puff, no matter how hard the user puffs on the mouthpiece 66.

In some embodiments, metering unit pump 60 is configured to deliver a fixed amount of liquid substrate upon detection of airflow, such as airflow indicative of a user puffing on mouthpiece 66 of device 20. For example, upon detection of a temperature difference between upstream sensor 82 and downstream sensor 84, controller 14 outputs a signal to metering unit 60 to deliver a fixed dose of liquid aerosol-forming substrate to heating surface 34. Compared to a continuous pumping system where liquid aerosol-forming substrate is continuously delivered when the heater is activated, this arrangement limits the amount of aerosol generated per puff. The liquid substrate forming the aerosol contains nicotine, and the nicotine in the aerosol delivered in each puff is therefore limited. This can provide a stable delivery of nicotine throughout the session of using the device.

In some embodiments, controller 14 is configured to energize light source 40 only upon detecting air flow through aerosol generating chamber 38. In such embodiments, the heating surface 34 can only be heated by drawing the generated aerosol through the aerosol generating chamber 38. This prevents the liquid substrate from drying out on the heating surface 34 and also protects the heating assembly 30 from overheating.

In some embodiments, the controller 14 is configured to track the puffing behavior of the user based on a determined airflow rate. Controller 14 may determine the puff speed, puff frequency, puff volume, or any combination thereof. Controller 14 may then determine the total amount of aerosol forming substrate inhaled by the user for each cycle of use. In the event that the aerosol-forming liquid substrate contains nicotine, the controller 14 may determine the total amount of nicotine inhaled by the user in each cycle of use. This allows the implementation of safe limits to limit the amount of nicotine inhaled by the user over a given period of time. For example, the aerosol generating device 20 may decrease the dose of the aerosol generating liquid substrate or may cease operation when the user approaches or exceeds a target nicotine value in each use cycle.

In some embodiments, controller 14 may refer to the monitored puff pattern and change the feedback control applied to the dispenser pump 60 and heater assembly 30. For example, controller 14 may determine an average puff duration or an average duration between puffs for a particular user. The controller 14 can subsequently use this information to control the heating and dosing of the aerosol-forming liquid substrate. The controller 14 can automatically stop the heating and dosing of the liquid substrate when the average puff duration is shortened. The controller 14 may also return the heating surface 34 when the average duration of the suspension completed to completion has elapsed. This allows rapid generation and delivery of the aerosol while improving the efficiency of the device 20.

In some embodiments, the aerosol generating device 20 includes only two or more temperature sensors 80, 82, 84. This arrangement reduces the amount of data that needs to be analyzed, thus reducing the complexity of process control. For example, determining the airflow through the aerosol generating chamber 38 can be achieved using only two temperature sensors spaced apart from each other. More specifically, in one embodiment, only upstream sensor 82 and downstream sensor 84 are provided without heater element sensor 80. Therefore, regulation of the heater temperature and liquid substrate dosing can be based on the temperature at the two sensors 82, 84 as well as a certain airflow rate, as described in the previous embodiment relating to FIG. 5b.

In some embodiments, only the heater element sensor 80 and the downstream sensor 84 are provided in the aerosol generating device 20. The airflow rate through the aerosol generating chamber 38 can be determined based on the difference in the temperature of the heater and the air temperature downstream of the heating surface 34. More specifically, the airflow rate can be determined by determining the amount of heat dissipation at a particular temperature of the heating surface 34 of the heating element 32. The controller 14 may refer to a look-up table stored in memory to improve the accuracy of determining the air flow rate. The lookup table provides empirical airflow rates corresponding to different downstream and heater temperatures. The lookup table may also provide empirical airflow rates corresponding to different downstream temperatures, different heater temperatures, and downstream sensor 84 distance from heating surface 34.

In some embodiments, only one sensor 82 is located proximate the heating surface 34. For example, the temperature value at the upstream sensor 82 may allow the controller 14 to determine the frequency and duration of each puff based on the amount of cooling material upstream of the heating surface 34 induced by incoming air source. When the air flow does not flow in the air flow channel, as shown in FIG. 5a, the upstream air temperature is gradually heated at the time that the heating surface 34 is activated. As the user puffs on the mouthpiece 66, the incoming air causes immersion in the measured upstream temperature. Thus, the time history or change in temperature over time, upstream, is indicative of the air flow and thus the manner in which the user puffs. The use of upstream sensor 82 can also serve as an automatic initiator to heat heating surface 34 and pump liquid substrate.

In some embodiments, only downstream sensor 84 is provided in aerosol generating device 20. More specifically, the heater element sensor 80 and the upstream sensor 82 are omitted. Referring to the lookup table, the controller 14 is configured to estimate the heater temperature from the power consumed by the light source 40. The controller may then determine the airflow rate based on the difference in the estimated heater temperature and the air temperature measured by downstream sensor 84 using the method described with respect to the embodiment shown in FIG. 5b.

In some embodiments, a plurality of heater element sensors 80 are provided along the length of the heating surface 34. The heating surface 34 includes a plurality of heating sections. Each of the heating element sensors 80 is provided in a respective heating section to detect the temperature at the heating location. Each of the heating sections is independently powered by a respective local light source. For example, each of the local light sources is an LED in an array of 40 LEDs.

In use, the lack of air flow through the aerosol generating chamber 38 results in no air cooling on the heating surface 34, thus the heating section temperatures measured by each of the heating element sensors 80 should return to the same value. As the user puffs on the mouthpiece 66, the incoming air cools down the portion of the heating surface 34 that is closest to the air inlet, such as the upstream heating surface. This results in different temperature readings over the plurality of heater element sensors 80 across different heating sections. Thus, the air flow rate can be determined based on the relative difference between the temperature of the heater measured across different heating sections.

In addition, a plurality of heating element sensors 80 arranged along the heating surface 34 provide localized heating control. For example, the controller is configured to control the power supplied to each of the local light sources based on the respective heating element sensor 80. This is particularly advantageous since more power can be supplied to the local light source to energize the upstream heating section to compensate for the cooling caused by the ambient air.

The exemplary embodiments described above are intended to be descriptive and not restrictive. Upon reading the exemplary embodiments discussed above, those skilled in the art will recognize other embodiments corresponding to the exemplary embodiments described above.

Claims (51)

1. A device that generates an aerosol and contains: air inlet; air outlet, an air flow channel extending in a first direction between the air inlet and the air outlet; a heating element in the air flow path for heating the aerosol-forming substrate; a first temperature sensor for measuring a first temperature at a first position along the airflow path, the first position being a position on the heating element and the first temperature being the temperature of the heating element at the first position; a second temperature sensor located at a distance from the first sensor in the first direction, to measure the second temperature at a second position along the air flow channel, and the second position is a position downstream relative to the heating element and the second temperature is the ambient temperature of the air flow channel in said second position; a third temperature sensor for measuring a third temperature at a third position along the airflow path, the third position being a position upstream of the heating element and the third temperature being the ambient temperature of the airflow path at said third position; and a controller configured to control an operating parameter of the device based on the measured first temperature, the measured second temperature, and the measured third temperature. 2. An aerosol generating device comprising: air inlet; air outlet, an air flow channel extending in a first direction between the air inlet and the air outlet; a heating element in the air flow path for heating the aerosol-forming substrate; a first temperature sensor for measuring a first temperature at a first position along the airflow path; a second temperature sensor located at a distance from the first sensor in the first direction, for measuring the second temperature at a second position along the air flow channel; a controller configured to control an operating parameter of the device based on the measured first temperature and the measured second temperature; a liquid storage part containing an aerosol-forming substrate; and a pump for pumping the aerosol-forming substrate from the liquid storage portion to the heating element; wherein the operating parameter of the device includes the flow rate of the aerosol-forming substrate from the liquid storage portion to the heating element, wherein the controller is configured to control the flow rate of the aerosol-forming substrate based on the measured first temperature and the measured second temperature. 3. An aerosol generating device comprising: air inlet; air outlet, an air flow channel extending in a first direction between the air inlet and the air outlet; Light source; a heating element in the air flow path for heating the aerosol-forming substrate, the heating element comprising a plurality of metal nanoparticles arranged to receive light from the light source and generate heat using surface plasmon resonance; a first temperature sensor for measuring a first temperature at a first position along the airflow path; a second temperature sensor located at a distance from the first sensor in the first direction, for measuring the second temperature at a second position along the air flow channel; and a controller configured to control an operating parameter of the device based on the measured first temperature and the measured second temperature. 4. An aerosol generating device according to claim 3, wherein the heating element comprises a plurality of individual regions of metal nanoparticles, said plurality of individual regions being spaced apart on the heating element. 5. An aerosol generating device according to claim 3 or 4, wherein the light source comprises a plurality of light sources, wherein at least one of the light sources is configured to irradiate only a portion of the plurality of metal nanoparticles. 6. An aerosol generating apparatus according to any one of the preceding claims, wherein the heating element comprises a plurality of heating sections, each of the first temperature sensor and the second temperature sensor being located on a respective heating element heating section. 7. The aerosol generating apparatus of claim 6, wherein the controller is configured to determine a temperature distribution across the plurality of heating sections and control power supplied to the plurality of heating sections based on the determined temperature distribution. 8. An aerosol generating apparatus according to any one of the preceding claims, wherein the controller is configured to determine a temperature distribution across the heating element and control an operating parameter based on the determined temperature distribution. 9. An aerosol generating device according to any one of the previous paragraphs, in which the operating parameter of the device includes the temperature of the heating element; wherein the controller is configured to control an outlet temperature of at least a portion of the heating element based on the measured first temperature and the measured second temperature. 10. An aerosol generating apparatus according to any one of the preceding claims, wherein the controller is configured to determine an airflow rate through the airflow path based on the measured first temperature and the measured second temperature. 11. An aerosol generating device according to claim 10, wherein the controller is configured to control the operating parameter based on the detected air flow. 12. An aerosol generating system comprising an aerosol generating device according to any one of the preceding claims and an aerosol generating article comprising an aerosol generating substrate. 13. A method for controlling an aerosol generating device containing a heating element in an air flow channel extending in a first direction, the method comprising the steps of: measuring a first temperature at a first position along the airflow path, the first position being a position on the heating element and the first temperature being the temperature of the heating element at the first position; a second temperature is measured at a second position along the airflow channel, wherein the second position is located at a distance from the first direction in the first direction, the second position being the position downstream of the heating element and the second temperature being the ambient temperature of the airflow channel in said second position; measuring a third temperature at a third position along the airflow path, the third position being the upstream position of the heating element and the third temperature being the ambient temperature of the airflow path at said third position; and adjusting an operating parameter of the device based on the measured first temperature, the measured second temperature, and the measured third temperature. 14. Method for controlling an aerosol generating device comprising a heating element in an air flow channel extending in the first direction, a liquid storage portion containing an aerosol generating substrate, and a pump for pumping the aerosol generating substrate from the liquid storage portion to the heating element , wherein the method includes the steps of: measuring a first temperature at a first position along the airflow channel; measuring a second temperature at a second position along the airflow channel, the second position being spaced in a first direction from the first position; and adjusting the operating parameter of the device based on the measured first temperature and the measured second temperature, wherein the operating parameter of the device includes the flow rate of the aerosol-forming substrate from the liquid storage part to the heating element, wherein the step of controlling the operating parameter of the device includes controlling the flow rate of the substrate, forming an aerosol based on the measured first temperature and the measured second temperature. 15. A method for controlling an aerosol generating device containing a light source and a heating element in an air flow channel passing in the first direction, wherein the heating element contains a plurality of metal nanoparticles arranged to receive light from the light source and generate heat through surface plasmon resonance, wherein the method includes the steps of: measuring a first temperature at a first position along the airflow channel; measuring a second temperature at a second position along the airflow channel, the second position being at a distance in the first direction from the first position; and adjusting an operating parameter of the device based on the measured first temperature and the measured second temperature.

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