Aerosol generating device and method of operation thereof

Abstract

According to one embodiment, the aerosol generating device includes a heater that heats at least a portion of the aerosol product, a puff sensor that detects a user's puffs, and a processor electrically connected to the heater and the puff sensor, wherein the processor detects the number of remaining puffs for the aerosol product through the puff sensor, compares the detected number of remaining puffs with a predetermined number of puffs, and if the detected number of remaining puffs is less than the predetermined number of puffs, stops supplying power to the heater for a predetermined time, and after the predetermined time has elapsed, supplies power to the heater so that the temperature of the heater reaches a target temperature corresponding to the number of remaining puffs. Various other embodiments are possible as will be understood throughout the specification.

Description

[Technical Field]

[0001] The present invention relates to an aerosol generating device and a method of operating the same, and more particularly to an aerosol generating device that controls power supply to a heater based on the number of puffs remaining for an aerosol product. [Background technology]

[0002] Recently, there has been an increasing demand for alternative methods to overcome the drawbacks of conventional cigarettes, such as a system that generates aerosol by heating a cigarette or an aerosol-generating substance using an aerosol-generating device, rather than a method that generates aerosol by burning a cigarette.

[0003] When an aerosol product is inserted into the accommodation space of the aerosol generating device, the device can heat the aerosol product according to a predetermined temperature profile. Here, the temperature profile refers to temperature change data of the heater or the aerosol product during smoking. Therefore, the predetermined temperature profile is a temperature profile set so that a certain amount of aerosol is generated by heating the aerosol product. Summary of the Invention [Problem to be solved by the invention]

[0004] When an aerosol generating device controls the power supply to the heater according to a time-dependent temperature profile, an inconsistent amount of aerosol may be generated during a user's smoking action, particularly in the latter half of the smoking action, resulting in an unsatisfactory smoking experience for the user.

[0005] Furthermore, even though the puff period differs for each user during smoking, if the aerosol generating device controls the power supply based on a time-dependent temperature profile, each user will be provided with a different amount of atomization, smoking taste, etc., which may reduce the user's smoking experience.

[0006] Various embodiments of the present invention provide an aerosol generating device that can generate a constant amount of aerosol during smoking by controlling the power supply to the heater based on the number of remaining puffs of the aerosol product.

[0007] The problems to be solved by the present invention are not limited to the above-mentioned problems, and unmentioned problems will be clearly understood by a person having ordinary skill in the art to which the embodiments pertain from this specification and the accompanying drawings. [Means for solving the problem]

[0008] An aerosol generating device according to one embodiment includes a heater for heating at least a portion of an aerosol product, a puff sensor for sensing a user's puffs, and a processor electrically connected to the heater and the puff sensor. The processor detects the number of remaining puffs for the aerosol product through the puff sensor, compares the detected number of remaining puffs with a predetermined number of puffs, and if the detected number of remaining puffs is less than the predetermined number of puffs, interrupts the supply of power to the heater for a predetermined time, and after the predetermined time has elapsed, supplies power to the heater so that the temperature of the heater reaches a target temperature corresponding to the number of remaining puffs.

[0009] A method of operating an aerosol generating device according to one embodiment includes the steps of detecting the number of remaining puffs for an aerosol product through a puff sensor that senses a user's puffs, comparing the detected number of remaining puffs with a predetermined number of puffs, and if the detected number of remaining puffs is less than the predetermined number of puffs, interrupting the supply of power to a heater that heats at least a portion of the aerosol product for a predetermined time, and after the predetermined time has elapsed, supplying power to the heater so that the temperature of the heater reaches a target temperature corresponding to the number of remaining puffs. [Effects of the Invention]

[0010] According to various embodiments of the present invention, the power supplied to the heater is controlled according to the number of remaining puffs, thereby allowing for appropriate control that reflects the user's puff cycle and smoking intensity.

[0011] However, the effects of the embodiments are not limited to the effects described above, and effects not mentioned will be clearly understood by those having ordinary skill in the art to which the embodiments pertain from this specification and the accompanying drawings. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a block diagram of an aerosol generating device according to one embodiment. [Figure 2] 10 is a flowchart illustrating a method for controlling power supply to a heater in an aerosol generating device according to an embodiment. [Figure 3A] 1 is a graph showing the relationship between the number of remaining puffs and the supplied power of an aerosol generating device according to an embodiment. [Figure 3B] 1 is a graph showing a temperature profile according to the number of remaining puffs of an aerosol generating device according to one embodiment. [Figure 4A] 10 is a graph showing the relationship between the number of remaining puffs and the supplied power of the aerosol generating device according to another embodiment. [Figure 4B] 10 is a graph showing a temperature profile according to the number of remaining puffs of an aerosol generating device according to another embodiment. [Figure 5] 10 is a flowchart illustrating a method in which an aerosol generating device according to an embodiment controls power supply to a heater when a user puff is not detected. [Figure 6] 6 is a graph showing the relationship between the power supply and the aerosol generating device of FIG. 5. [Figure 7] 10 is a flowchart illustrating a method in which an aerosol generating device according to an embodiment changes the default number of puffs based on the initial heating rate of a heater. [Figure 8] 10 is an exemplary diagram illustrating an aerosol generating device according to an embodiment, which reduces the predetermined number of puffs based on the initial heating rate of the heater. FIG. [Figure 9] 10 is an exemplary diagram illustrating an aerosol generating device according to an embodiment, which increases the predetermined number of puffs based on the initial heating rate of the heater. FIG. [Figure 10] FIG. 10 is a block diagram of an aerosol generating device according to yet another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] The terms used in the embodiments are currently commonly used terms, and are selected as much as possible while taking into consideration the functions of the present invention. However, this may vary depending on the intentions or precedents of engineers in the field, the emergence of new technologies, etc. In addition, in certain cases, the applicant may arbitrarily select terms, and in such cases, their meanings will be described in detail in the description of the invention. Therefore, the terms used in the present invention must be defined based on the meanings of the terms and the overall content of the present invention, rather than simply the names of the terms.

[0014] Throughout the specification, when a part "includes" a certain component, it does not mean that it excludes other components and may further include other components, unless otherwise specified. Furthermore, terms such as "... unit" and "... module" used in the specification refer to a unit that processes at least one function or operation, and may be realized by hardware or software, or a combination of hardware and software.

[0015] As used herein, when a phrase such as "at least one of" precedes an array of elements, it modifies the entire array and not each individual element in the array. For example, the phrase "at least one of a, b, and c" should be interpreted as including a, b, and c, or a and b, a and c, b and c, or a, b, and c.

[0016] In one embodiment, the aerosol generating device is also a device that generates the aerosol by electrically heating a cigarette contained in the interior space.

[0017] The aerosol generating device includes a heater. In one embodiment, the heater is an electrically resistive heater. For example, the heater may include a conductive track, and when an electric current is passed through the conductive track, the heater may be heated.

[0018] The heater may include a tubular heating element, a plate-shaped heating element, a needle-shaped heating element, or a rod-shaped heating element, and may heat the interior or exterior of the cigarette depending on the shape of the heating element.

[0019] Cigarettes include tobacco rods and filter rods. Tobacco rods can be made in sheet or strand form, and tobacco sheets can be made from shredded tobacco. The tobacco rod is surrounded by a thermally conductive material. For example, the thermally conductive material can be a metal foil such as aluminum foil, but is not limited to this.

[0020] The filter rod may also be a cellulose acetate filter. The filter rod may be composed of at least one or more segments. For example, the filter rod may include a first segment that cools the aerosol and a second segment that filters out specific components contained in the aerosol.

[0021] In other embodiments, the aerosol generating device is a device that generates an aerosol using a cartridge that holds an aerosol generating substance.

[0022] The aerosol generating device includes a cartridge that holds an aerosol generating material and a body that supports the cartridge. The cartridge is detachably connected to the body, but is not limited thereto. The cartridge may be formed integrally with the body or assembled and fixed so that it cannot be removed by a user. The cartridge may be attached to the body with the aerosol generating material stored therein. However, the invention is not limited thereto, and the aerosol generating material may be injected into the cartridge while the cartridge is connected to the body.

[0023] The cartridge holds an aerosol-forming material in any one of a variety of states, such as a liquid state, a solid state, a gas state, or a gel state. The aerosol-forming material may include a liquid composition. For example, the liquid composition may be a liquid containing a tobacco-containing substance including a volatile tobacco flavor component, or a liquid containing a non-tobacco substance.

[0024] The cartridge is activated by an electrical signal or a wireless signal transmitted from the main body, and functions to convert the phase of the aerosol-generating material inside the cartridge into a gas phase to generate an aerosol. The aerosol refers to a gas in which vaporized particles generated from the aerosol-generating material are mixed with air.

[0025] In yet another embodiment, the aerosol generating device heats a liquid composition to generate an aerosol, and the generated aerosol can be delivered to the user through the cigarette, i.e., the aerosol generated from the liquid composition travels along an airflow passage of the aerosol generating device, and the airflow passage can be configured to deliver the aerosol through the cigarette to the user.

[0026] In yet another embodiment, the aerosol generating device is a device that generates an aerosol from an aerosol generating material using an ultrasonic vibration method. In this case, the ultrasonic vibration method refers to a method of generating an aerosol by atomizing an aerosol generating material using ultrasonic vibrations generated by a vibrator.

[0027] The aerosol generating device includes a vibrator that generates short-period vibrations to atomize the aerosol generating material. The vibrations generated by the vibrator are ultrasonic vibrations, and the frequency band of the ultrasonic vibrations is about 100 kHz to about 3.5 MHz, but is not limited thereto.

[0028] The aerosol generating device may further include a wick that absorbs the aerosol-generating substance, for example, the wick being positioned to surround or contact at least a region of the transducer.

[0029] When a voltage (e.g., an AC voltage) is applied to the vibrator, heat and / or ultrasonic vibrations are generated from the vibrator, and the heat and / or ultrasonic vibrations generated from the vibrator are transferred to the aerosol-forming substance absorbed in the wick. The aerosol-forming substance absorbed in the wick is converted into a gas phase by the heat and / or ultrasonic vibrations transferred from the vibrator, resulting in the generation of an aerosol.

[0030] For example, the viscosity of the aerosol-generating substance absorbed into the core is reduced by heat generated from the vibrator, and the reduced viscosity aerosol-generating substance is broken down into fine particles by ultrasonic vibrations generated from the vibrator, thereby generating an aerosol, but this is not limited to this.

[0031] In yet another embodiment, the aerosol generating device is a device that generates an aerosol by heating an aerosol product contained in the aerosol generating device by induction heating.

[0032] The aerosol generating device includes a susceptor and a coil. In one embodiment, the coil can apply a magnetic field to the susceptor. When power is supplied from the aerosol generating device to the coil, a magnetic field is formed inside the coil. In one embodiment, the susceptor is a magnetic material that generates heat when an external magnetic field is applied. The susceptor is located inside the coil, and generates heat when a magnetic field is applied, thereby heating the aerosol product. Alternatively, the susceptor can be located inside the aerosol product.

[0033] In yet another embodiment, the aerosol generating device may further include a cradle.

[0034] The aerosol generating device may be configured as a system together with a separate cradle. For example, the cradle may charge a battery of the aerosol generating device. Alternatively, the heater may be heated when the cradle and the aerosol generating device are coupled together.

[0035] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement them. The present invention may be embodied in a form that can be implemented in the aerosol generating device of the various embodiments described above, or may be embodied in various different forms, and is not limited to the embodiments described herein.

[0036] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0037] FIG. 1 is a block diagram of an aerosol generating device according to one embodiment.

[0038] 1, the aerosol generating device 100 includes a processor 110, a heater 120, and a puff sensor 130. However, the internal hardware components of the aerosol generating device 100 are not limited to those shown in Fig. 1. It will be understood by those skilled in the art that some of the hardware components shown in Fig. 1 may be omitted or new components may be added depending on the design of the aerosol generating device 100.

[0039] Hereinafter, the operation of each component included in the aerosol generating device 100 will be described without limiting the space in which the component is located.

[0040] In one embodiment, the heater 120 can heat at least a portion of an aerosol product inserted into the aerosol generating device 100. For example, the heater 120 can be supplied with power from a battery (not shown) under the control of the processor 110, and can generate an aerosol by heating at least a portion of the aerosol product through the supplied power.

[0041] In one embodiment, the heater 120 may be a resistance heating heater or an induction heating heater. For example, if the heater 120 is a resistance heating heater, the heater 120 may be formed of any electrically resistive material or may be implemented as a metal hot wire, a metal hot plate with conductive tracks, a ceramic heating element, etc. As another example, if the heater 120 is an induction heating heater, the heater 120 may be implemented as a susceptor that generates heat through a magnetic field applied by an induction coil.

[0042] In one embodiment, the puff sensor 130 can sense a user's puff and communicate the sensed information to the processor 110 .

[0043] In one embodiment, the puff sensor 130 is also a pressure sensor that detects a user's puff by measuring pressure caused by changes in the internal airflow of the aerosol generating device 100. For example, the puff sensor 130 is disposed in an airflow passage, an open end, or the like within the aerosol generating device 100 to measure the internal pressure of the aerosol generating device 100, but the location of the puff sensor 130 is not limited thereto. In this case, the puff sensor 130 is any one of an absolute pressure sensor, a gauge pressure sensor, and a differential pressure sensor.

[0044] However, the puff sensor 130 is not limited thereto, and may be at least one of a temperature sensor, a humidity sensor, and a sensor that detects changes in electrical characteristics.

[0045] In one embodiment, the processor 110 may detect the number of remaining puffs for the aerosol product through the puff sensor 130. In this case, the "number of remaining puffs" refers to the number of remaining puffs a user can make for the aerosol product, and the processor 110 may detect the number of remaining puffs by subtracting the detected number of puffs from the number of remaining puffs for the aerosol product.

[0046] For example, if the number of puffs available for an aerosol product is 15 and the number of puffs already inhaled by the user is 10, the processor 110 may detect that there are 5 puffs remaining.

[0047] In one embodiment, the processor 110 can compare the detected number of remaining puffs with a predetermined number of puffs and control the power supply to the heater 120. For example, the processor 110 can control the power supply to the heater 120 based on pulse width modulation (PWM) control, proportional integral differential (PID) control, or the like.

[0048] In this case, the "predetermined number of puffs" refers to a reference number of puffs at which the processor 110 stops supplying power to the heater 120. For example, if the number of remaining puffs (e.g., 13 puffs) detected through the puff sensor 130 is equal to or greater than the predetermined number of puffs (e.g., 12 puffs), the processor 110 may supply power to the heater 120. As another example, if the number of remaining puffs (e.g., 11 puffs) detected through the puff sensor 130 is less than the predetermined number of puffs (e.g., 12 puffs), the processor 110 may stop supplying power to the heater 120.

[0049] In one embodiment, the predetermined number of puffs can be changed based on the initial heating rate of the heater 120, which will be described in detail later with reference to FIGS.

[0050] In addition, if the processor 110 does not detect a puff for a critical time after the user's puff is detected through the puff sensor 130, the processor 110 may interrupt the power supply to the heater 120 for a predetermined time, which will be described in detail later with reference to Figures 5 and 6.

[0051] 2 is a flowchart showing a method for controlling the power supply to the heater in an aerosol generating device according to an embodiment. The description of FIG. 2 corresponds to the description above, or the same or similar descriptions will be omitted.

[0052] 2, a processor (e.g., processor 110 of FIG. 1) may detect the number of remaining puffs through a puff sensor (e.g., puff sensor 130 of FIG. 1) in operation 201. For example, when an aerosol product is inserted into an aerosol generating device (e.g., aerosol generating device 100 of FIG. 1), processor 110 may supply power to a heater (e.g., heater 120 of FIG. 1) for preheating. Also, when a user starts smoking after the preheating period of heater 120 ends, processor 110 may detect the user's puffs through puff sensor 130. In this case, processor 110 may detect the number of remaining puffs by subtracting the detected number of puffs from the number of puffs possible for the inserted aerosol product (i.e., the maximum number of puffs).

[0053] For example, if the maximum number of puffs for an aerosol product is 15 and the number of puffs already sensed as having been inhaled by the user is 10, the processor 110 may detect 5 remaining puffs.

[0054] In one embodiment, the number of puffs that can be made for the inserted aerosol product is stored in a separate memory (not shown). In this case, if the number of puffs that can be made varies depending on the type of aerosol product, the memory may store the maximum number of puffs for each type of aerosol product. For example, if the maximum number of puffs for a first aerosol product (first type) is 15 and the maximum number of puffs for a second aerosol product (second type) is 10, the memory may store the maximum number of puffs for each type of aerosol product (e.g., the maximum number of puffs for the first aerosol product is "15," and the maximum number of puffs for the second aerosol product is "10").

[0055] The processor 110 can then sense the type of aerosol product inserted into the device 100 through a separate sensor (not shown) and obtain maximum puff number data for the sensed type of aerosol product from memory.

[0056] According to one embodiment, in operation 203, the processor 110 may compare the detected number of remaining puffs with a predetermined number of puffs, where the "predetermined number of puffs" refers to a reference number of puffs after which the processor 110 cuts off power to the heater 120.

[0057] In one embodiment, if the detected number of puffs remaining is less than the predetermined number of puffs, processor 110 may interrupt power supply to heater 120 for a predetermined time in operation 205. In another embodiment, if the detected number of puffs remaining is equal to or greater than the predetermined number of puffs, processor 110 may return to operation 201 and repeat the following operations.

[0058] For example, if the detected number of remaining puffs is equal to or greater than a predetermined number of puffs, the processor 110 can supply power to the heater 120 based on the first temperature profile, and if the detected number of remaining puffs becomes less than the predetermined number of puffs, the processor 110 can interrupt the supply of power to the heater 120 for a predetermined period of time.

[0059] In this case, the "first temperature profile" is a temperature profile for the number of remaining puffs detected by the puff sensor 130, and is a temperature profile including a temperature rising section in which the temperature of the heater 120 rises to a critical temperature.

[0060] The "predetermined time" for which the power supply is interrupted refers to the time it takes for the temperature of the heater 120 to decrease to a predetermined temperature, which corresponds to a predetermined number of puffs (e.g., 2 to 5) by the user. The "predetermined time" may be preset by the manufacturer.

[0061] For example, if the number of remaining puffs detected by the puff sensor 130 is 11 and the predetermined number of puffs is 12, the processor 110 may interrupt the supply of power to the heater 120 for a predetermined time (e.g., 30 seconds). However, even if the supply of power to the heater 120 is interrupted for the predetermined time, the heater 120 still has a substantially high temperature (i.e., a temperature that can heat the aerosol-producing article to generate an aerosol), allowing the user to perform a smoking action for the predetermined time.

[0062] Compared to the conventional method of lowering the heater temperature by reducing the supplied power, this method improves power efficiency by interrupting the power supply to the heater 120 for a predetermined time. That is, even if the power supply is interrupted for a predetermined time, the temperature of the heater 120 gradually decreases, so by adjusting the "predetermined time" for interrupting the power supply, the temperature of the heater 120 can be reduced to a target temperature, thereby improving power efficiency.

[0063] According to one embodiment, if the power supply to the heater 120 is interrupted and a predetermined time has elapsed, the processor 110 can, in operation 207, supply power based on a second temperature profile so that the temperature of the heater 120 reaches a target temperature corresponding to the number of remaining puffs.

[0064] In this case, the "number of remaining puffs" refers to the number of remaining puffs at a predetermined time after the power supply to the heater 120 is interrupted.

[0065] The "second temperature profile" is a temperature profile for the number of remaining puffs detected by the puff sensor 130, and is a temperature profile in which the target temperature increases as the number of remaining puffs decreases.

[0066] For example, if the number of remaining puffs detected by puff sensor 130 is 11 and the default number of puffs is 12, processor 110 may interrupt the power supply to heater 120 for a predetermined time (e.g., 30 seconds). In this case, if the user performs two puffs within the predetermined time, processor 110 may detect that the number of remaining puffs is 9 when the predetermined time has elapsed.

[0067] The processor 110 can then supply power to the heater 120 so that the temperature of the heater 120 reaches a target temperature (e.g., 250°C) corresponding to the remaining number of puffs of "8." As the remaining number of puffs decreases, such as "7," "6," "5," etc., the target temperature corresponding to the remaining number of puffs increases, such as "265°C," "280°C," "295°C," etc.

[0068] 3A and 3B are graphs showing the relationship between the power supply and the number of remaining puffs in an aerosol generating device according to an embodiment, respectively, and the temperature profile and the number of remaining puffs in an aerosol generating device according to an embodiment.

[0069] 3A and 3B, a processor (e.g., processor 110 of FIG. 1) may control the power supply to a heater (e.g., heater 120 of FIG. 1) according to a first section 310, a second section 315, and a third section 320. Here, first section 310 corresponds to a section where the number of remaining puffs is 15 to 11, second section 315 corresponds to a section where the number of remaining puffs is 11 to 8, and third section 320 corresponds to a section where the number of remaining puffs is 8 to 1, and power supply to heater 120 may be interrupted and resumed at the remaining puff numbers (e.g., "11" and "8") that overlap in each section.

[0070] In one embodiment, the first section 310 corresponds to a section in which power is supplied to the heater 120 within the power supply range 330 so that the temperature of the heater 120 is controlled based on a first temperature profile. The second section 315 corresponds to a section in which power supply to the heater 120 is interrupted so that the temperature of the heater 120 is substantially reduced. The third section 320 corresponds to a section in which power is supplied to the heater 120 within the power supply range 330 so that the temperature of the heater 120 is controlled based on a second temperature profile different from the first temperature profile.

[0071] In this case, the first temperature profile and the second temperature profile include a temperature increase section in which the temperature of the heater 120 increases as the number of remaining puffs decreases, and in particular, the first temperature profile includes a temperature increase section in which the temperature of the heater 120 increases to the critical temperature 340.

[0072] For example, if the default puff number 300, which is the reference number of puffs at which the processor 110 stops supplying power to the heater 120, is set to "12 puffs," the processor 110 can supply power to the heater 120 in the first section 310 until the remaining number of puffs becomes "11 puffs," which is less than the default puff number 300, and then stop supplying power.

[0073] At this time, the final power supply to the heater 120 in the first section 310 is the maximum value of the power supply range 330 , and thus the temperature of the heater 120 may rise to the critical temperature 340 .

[0074] The processor 110 may interrupt the supply of power to the heater 120 during the second interval 315, which corresponds to a predetermined time period (e.g., 30 seconds). In this case, the temperature of the heater 120 gradually decreases from the critical temperature 340 during the second interval 315, and a user's smoking behavior may be detected during the second interval 315. For example, even if the supply of power to the heater 120 is interrupted during the second interval 315, the number of puffs may be counted because a user's puffs are detected.

[0075] When the processor 110 detects a puff from the user after the predetermined time has elapsed, the processor 110 can resume supplying power to the heater 120. For example, if the number of remaining puffs is "8" when the predetermined time (e.g., 30 seconds) has elapsed, the processor 110 can supply power to the heater 120 so that the temperature of the heater 120 reaches a target temperature (e.g., 250°C) corresponding to the remaining number of puffs, "8."

[0076] At this time, the initial power supply to the heater 120 in the third section 320 is the minimum value of the power supply range 330, thereby allowing the temperature of the heater 120 to reach the target temperature. Then, as the number of remaining puffs in the third section 320 decreases, the target temperature of the heater 120 increases, so the processor 110 can gradually increase the power supply to the heater 120.

[0077] 4A and 4B are graphs showing the relationship between the power supply and the number of remaining puffs in an aerosol generating device according to another embodiment, and the temperature profile and the number of remaining puffs in an aerosol generating device according to another embodiment.

[0078] 4A and 4B, a processor (e.g., processor 110 of FIG. 1) may control the power supply to a heater (e.g., heater 120 of FIG. 1) according to a first section 410, a second section 415, and a third section 420. Here, first section 410 corresponds to a section where the number of remaining puffs is 15 to 11, second section 415 corresponds to a section where the number of remaining puffs is 11 to 8, and third section 420 corresponds to a section where the number of remaining puffs is 8 to 1, and power supply to heater 120 may be interrupted and resumed at the remaining puff numbers (e.g., “11” and “8”) that overlap in each section.

[0079] In one embodiment, the first section 410 corresponds to a section in which power is supplied to the heater 120 within the power supply range 430 so that the temperature of the heater 120 is controlled based on a first temperature profile. The second section 415 corresponds to a section in which power supply to the heater 120 is interrupted so that the temperature of the heater 120 is substantially reduced. The third section 420 corresponds to a section in which power is supplied to the heater 120 within the power supply range 430 so that the temperature of the heater 120 is controlled based on a second temperature profile different from the first temperature profile.

[0080] In this case, the first temperature profile includes a temperature rising section in which the temperature of the heater 120 increases up to the critical temperature 440, and a temperature falling section in which the temperature of the heater 120 decreases after reaching the critical temperature 440, and the second temperature profile includes only a temperature rising section in which the temperature of the heater 120 increases as the number of remaining puffs decreases.

[0081] For example, if the predetermined number of puffs 400, which is the reference number of puffs at which the processor 110 stops supplying power to the heater 120, is set to "12 puffs," the processor 110 can supply power to the heater 120 in the first section 410 until the remaining number of puffs becomes "11 puffs," which is less than the predetermined number of puffs 400, and then stop supplying power.

[0082] At this time, the final power supply value in the first section 410 to the heater 120 is a power value less than the maximum value of the power supply range 430, so that the temperature of the heater 120 can rise to the critical temperature 440 and then fall.

[0083] The processor 110 may interrupt the supply of power to the heater 120 during the second interval 415, which corresponds to a predetermined time period (e.g., 30 seconds). At this time, the temperature of the heater 120 gradually decreases during the second interval 415, and a user's smoking action may be detected during the second interval 415. For example, even if the supply of power to the heater 120 is interrupted during the second interval 415, the number of puffs may be counted because a user's puffs may be detected.

[0084] When the processor 110 detects a puff from the user after the predetermined time has elapsed, the processor 110 can resume supplying power to the heater 120. For example, if the number of remaining puffs is "8" when the predetermined time (e.g., 30 seconds) has elapsed, the processor 110 can supply power to the heater 120 so that the temperature of the heater 120 reaches a target temperature (e.g., 250°C) corresponding to the remaining number of puffs, "8."

[0085] At this time, the initial power supply to the heater 120 in the third section 420 is the minimum value of the power supply range 430, thereby allowing the temperature of the heater 120 to reach the target temperature. Then, as the number of remaining puffs in the third section 420 decreases, the target temperature of the heater 120 increases, and therefore the processor 110 can gradually increase the power supply to the heater 120.

[0086] FIG. 5 is a flowchart illustrating a method in which an aerosol generating device according to an embodiment controls power supply to a heater when a user puff is not detected.

[0087] Referring to FIG. 5, in operation 501, a processor (e.g., processor 110 of FIG. 1) may interrupt power supply to a heater (e.g., heater 120 of FIG. 1) for a predetermined time if no puff is detected for a critical time after a user's puff is detected via a puff sensor (e.g., puff sensor 130 of FIG. 1).

[0088] For example, the processor 110 may interrupt the supply of power to the heater 120 for a predetermined time (e.g., 20 seconds) if no puffs are detected for a critical time (e.g., 1 minute) after the user's most recent puff is detected via the puff sensor 130.

[0089] When the aerosol generating device according to the present invention (e.g., the aerosol generating device 100 of FIG. 1) controls the power supply to the heater 120 based on the number of puffs by the user, if a constant power is continuously supplied to the heater 120 even though no puffs by the user are detected for a long period of time, defects such as overheating of the heater 120 and malfunction of the aerosol generating device 100 may occur. Therefore, if no puffs by the user are detected for a critical time, the processor 110 may determine that the user's puffs have temporarily stopped, and may interrupt the power supply to the heater 120 for a predetermined time.

[0090] According to one embodiment, the processor 110 may, in operation 503, supply power to the heater 120 after a predetermined time that corresponds to the minimum value of a range of power to be supplied to the heater 120.

[0091] For example, the processor 110 may resume the power supply to the heater 120 after a predetermined time (e.g., 20 seconds) has elapsed since the power supply to the heater 120 was interrupted. At this time, the power supplied to the heater 120 corresponds to the minimum value of the power supply range to the heater 120.

[0092] This is to prevent the temperature of the heater 120 from decreasing to a substantially low temperature (i.e., a temperature at which aerosol cannot be generated from the aerosol product) while determining that the user's puff has been temporarily stopped and halting the supply of power to the heater 120 for a predetermined time. However, to prevent a sudden increase in the temperature of the heater 120 and unnecessary power consumption, the processor 110 may supply power corresponding to the minimum value of the supply power range to the heater 120.

[0093] FIG. 6 is a graph showing the relationship between the power supply and the aerosol generating device of FIG.

[0094] 6, a processor (e.g., processor 110 of FIG. 1) can detect a user's most recent puff 600 through a puff sensor (e.g., puff sensor 130 of FIG. 1). Then, if no user puffs are detected after the most recent puff 600 for a critical time 610, processor 110 can interrupt power supply to a heater (e.g., heater 120 of FIG. 1) for a predetermined time 620.

[0095] The processor 110 may then resume supplying power to the heater 120 after a predetermined time 620 has elapsed since the power supply to the heater 120 was interrupted. When resuming power supply after the predetermined time 620 has elapsed, the processor 110 may supply power to the heater 120 that corresponds to the minimum value of the range of power supplied to the heater 120.

[0096] 7 is a flowchart illustrating a method for changing the predetermined number of puffs based on the initial heating rate of the heater in an aerosol generating device according to an embodiment. FIG. 7 is a flowchart embodying the operations prior to operation 201 in FIG. 2.

[0097] 7, a processor (e.g., processor 110 of FIG. 1) may detect an initial temperature rise rate of a heater (e.g., heater 120 of FIG. 1) in operation 701. Here, the "initial temperature rise rate" refers to the rate at which the temperature of the heater 120 reaches a target preheat temperature in a preheating section in which the heater 120 is preheated. The initial temperature rise rate of the heater 120 may vary depending on the state of the aerosol product inserted into the aerosol generating device (e.g., aerosol generating device 100 of FIG. 1).

[0098] According to one embodiment, the processor 110 may determine whether the initial heating rate of the heater 120 exceeds a critical rate range in operation 703. Here, the "critical rate range" refers to the heating rate range of the heater 120 in the preheating section when the aerosol product inserted into the aerosol generating device 100 is in a normal state.

[0099] In one embodiment, if the initial heating rate of the heater 120 exceeds the critical rate range, the processor 110 may determine that a first abnormal condition has occurred, which indicates that the thickness of the inserted aerosol product is too thin. That is, the first abnormal condition indicates that the thickness of the aerosol product is too thin, and heat generated by the heater 120 is not transferred to the aerosol product.

[0100] According to one embodiment, if the initial temperature rise rate of the heater 120 exceeds the critical rate range, the processor 110 may change the predetermined number of puffs to a lower number of puffs in operation 705. For example, the processor 110 may supply power to the heater 120 based on a profile of a temperature rise section that increases the temperature of the heater 120 until the number of remaining puffs for the aerosol product reaches the predetermined number of puffs. However, if the aerosol product falls into the first abnormal state and heat generated by the heater 120 is not transferred, the processor 110 may change the predetermined number of puffs to a lower number of puffs, thereby setting a longer temperature rise section that increases the temperature of the heater 120.

[0101] According to one embodiment, the processor 110 may determine in operation 707 whether the initial heat-up rate of the heater 120 is below a critical rate range.

[0102] In one embodiment, if the initial heating rate of the heater 120 is below the critical rate range, the processor 110 may determine that the inserted aerosol product is in a second abnormal state, meaning that the product contains a large amount of moisture. That is, the second abnormal state refers to an overly humid state, meaning that the aerosol product contains a large amount of moisture due to external environmental conditions or manufacturing conditions.

[0103] According to one embodiment, if the initial temperature rise rate of the heater 120 is below the critical rate range, the processor 110 may change the predetermined number of puffs to a higher number of puffs in operation 709. For example, the processor 110 may supply power to the heater 120 based on a profile of a temperature rise section that increases the temperature of the heater 120 until the number of remaining puffs for the aerosol product reaches the predetermined number of puffs. However, if the aerosol product falls into the second abnormal state and an excessively large amount of water vapor is generated from the aerosol product, the processor 110 may change the predetermined number of puffs to a higher number of puffs, thereby shortening the temperature rise section that increases the temperature of the heater 120.

[0104] FIG. 8 is an example diagram illustrating an aerosol generating device according to an embodiment, in which the predetermined number of puffs is reduced based on the initial heating rate of the heater.

[0105] Referring to graph (a) of Figure 8, the temperature rise rate of the heater 120 during the preheating period of the heater (e.g., heater 120 in Figure 1) may vary depending on the state of the aerosol product inserted into the aerosol generating device (e.g., aerosol generating device 100 in Figure 1).

[0106] For example, when the state of the aerosol product inserted into the aerosol generation device 100 is normal state 800, the heater 120 increases in temperature at a rate within the critical speed range in the preheating section. As another example, when the state of the aerosol product inserted into the aerosol generation device 100 is first abnormal state 810 (i.e., a state in which the thickness of the aerosol product is excessively thin), the heater 120 increases in temperature at a rate exceeding the critical speed range in the preheating section.

[0107] 8 , the processor 110 may change the predetermined number of puffs based on the initial heating rate of the heater 120 in the preheating section. For example, when the state of the aerosol product inserted into the aerosol generating device 100 is normal state 800, the initial heating rate of the heater 120 falls within the critical speed range, and the processor 110 may not change the predetermined number of puffs but may maintain the existing predetermined number of puffs at 820. As another example, when the state of the aerosol product inserted into the aerosol generating device 100 is first abnormal state 810, the initial heating rate of the heater 120 exceeds the critical speed range, and the processor 110 may change the existing predetermined number of puffs 820 to a new reference number of puffs 830.

[0108] FIG. 9 is an example diagram illustrating an aerosol generating device according to an embodiment, in which the predetermined number of puffs is increased based on the initial heating rate of the heater.

[0109] Referring to graph (a) of Figure 9, the temperature rise rate of the heater 120 during the preheating period of the heater (e.g., heater 120 in Figure 1) may vary depending on the state of the aerosol product inserted into the aerosol generating device (e.g., aerosol generating device 100 in Figure 1).

[0110] For example, when the state of the aerosol product inserted into the aerosol generation device 100 is the normal state 900, the heater 120 increases in temperature at a rate within the critical speed range in the preheating section. As another example, when the state of the aerosol product inserted into the aerosol generation device 100 is the second abnormal state (i.e., the aerosol product is in an overly humid state) 910, the heater 120 increases in temperature at a rate below the critical speed range in the preheating section.

[0111] 9 , the processor 110 may change the predetermined number of puffs based on the initial heating rate of the heater 120 in the preheating section. For example, when the state of the aerosol product inserted into the aerosol generating device 100 is the normal state 900, the initial heating rate of the heater 120 falls within the critical speed range, and the processor 110 may not change the predetermined number of puffs but may maintain the existing predetermined number of puffs at 920. As another example, when the state of the aerosol product inserted into the aerosol generating device 100 is the second abnormal state 910, the initial heating rate of the heater 120 is below the critical speed range, and the processor 110 may change the existing predetermined number of puffs 920 to a new reference number of puffs 930.

[0112] FIG. 10 is a block diagram of an aerosol generating device according to yet another embodiment.

[0113] The aerosol generating device 1000 includes a control unit 1010, a sensing unit 1020, an output unit 1030, a battery 1040, a heater 1050, a user input unit 1060, a memory 1070, and a communication unit 1080. However, the internal structure of the aerosol generating device 1000 is not limited to that shown in Fig. 10. That is, a person skilled in the art of this embodiment can understand that some of the components shown in Fig. 10 may be omitted or new components may be added depending on the design of the aerosol generating device 1000.

[0114] The sensing unit 1020 can sense the state of the aerosol generating device 1000 or the state around the aerosol generating device 1000 and transmit the sensed information to the control unit 1010. Based on the sensed information, the control unit 1010 can control the aerosol generating device 1000 to perform various functions such as controlling the operation of the heater 1050, restricting smoking, determining whether an aerosol product (e.g., cigarette, cartridge, etc.) is inserted, and displaying notifications.

[0115] The sensing unit 1020 includes, but is not limited to, at least one of a temperature sensor 1022, an insertion sensor 1024, and a puff sensor 1026.

[0116] The temperature sensor 1022 can sense the temperature to which the heater 1050 (or the aerosol-generating substance) is heated. The aerosol-generating device 1000 can include a separate temperature sensor that senses the temperature of the heater 1050, or the heater 1050 itself can function as a temperature sensor. Alternatively, the temperature sensor 1022 can be disposed around the battery 1040 to monitor the temperature of the battery 1040.

[0117] The insertion detection sensor 1024 can detect the insertion and / or removal of the aerosol product article. For example, the insertion detection sensor 1024 can include at least one of a film sensor, a pressure sensor, an optical sensor, a resistive sensor, a capacitive sensor, an inductive sensor, and an infrared sensor, and can detect a signal change due to the insertion and / or removal of the aerosol product article.

[0118] The puff sensor 1026 can sense a user's puff based on various physical changes in the airflow passage or channel, such as a temperature change, a flow change, a voltage change, or a pressure change.

[0119] The sensing unit 1020 may further include at least one of a temperature / humidity sensor, an air pressure sensor, a geomagnetic sensor, an acceleration sensor, a gyroscope sensor, a position sensor (e.g., GPS), a proximity sensor, and an RGB (illuminance) sensor, in addition to the aforementioned temperature sensor 1022, insertion sensor 1024, and puff sensor 1026. The function of each sensor can be intuitively inferred by a person skilled in the art from its name, so detailed description thereof will be omitted.

[0120] The output unit 1030 can output and provide to a user information about the status of the aerosol generating device 1000. The output unit 1030 includes, but is not limited to, at least one of a display unit 1032, a haptic unit 1034, and an audio output unit 1036. When the display unit 1032 and the touchpad form a layered structure to form a touch screen, the display unit 1032 is used as an input device in addition to an output device.

[0121] The display unit 1032 can visually provide a user with information about the aerosol generating device 1000. For example, the information about the aerosol generating device 1000 refers to various information such as the charge / discharge status of the battery 1040 of the aerosol generating device 1000, the preheating status of the heater 1050, the insertion / removal status of an aerosol product, or a status in which use of the aerosol generating device 1000 is restricted (e.g., abnormal item detection), and the display unit 1032 can output the information to the outside. The display unit 1032 can be, for example, a liquid crystal display panel (LCD), an organic light emitting display panel (OLED), etc. The display unit 1032 can also be in the form of an LED light emitting element.

[0122] The haptic unit 1034 can convert an electrical signal into a mechanical or electrical stimulus and provide the user with tactile information about the aerosol generating device 1000. For example, the haptic unit 1034 may include a motor, a piezoelectric element, or an electrical stimulation device.

[0123] The acoustic output unit 1036 can audibly provide the user with information about the aerosol generation device 1000. For example, the acoustic output unit 1036 can convert an electrical signal into an acoustic signal and output it to the outside.

[0124] The battery 1040 can supply power used to operate the aerosol generating device 1000. The battery 1040 can supply power to heat the heater 1050. The battery 1040 can also supply power necessary for the operation of other components included in the aerosol generating device 1000 (e.g., the sensing unit 1020, the output unit 1030, the user input unit 1060, the memory 1070, and the communication unit 1080). The battery 1040 may be a rechargeable battery or a disposable battery. For example, the battery 1040 is a lithium polymer (LiPoly) battery, but is not limited thereto.

[0125] The heater 1050 is supplied with power from the battery 1040 and can heat the aerosol-generating material. Although not shown in Fig. 10, the aerosol-generating device 1000 may further include a power conversion circuit (e.g., a DC / DC converter) that converts the power of the battery 1040 and supplies it to the heater 1050. Furthermore, when the aerosol-generating device 1000 generates an aerosol by an induction heating method, the aerosol-generating device 1000 may further include a DC / AC converter that converts the DC power of the battery 1040 into AC power.

[0126] The control unit 1010, the sensing unit 1020, the output unit 1030, the user input unit 1060, the memory 1070, and the communication unit 1080 can function by receiving power from a battery 1040. Although not shown in FIG. 10 , the device may further include a power conversion circuit, for example, an LDO (low dropout) circuit or a voltage regulator circuit, that converts the power of the battery 1040 and supplies it to each component.

[0127] In one embodiment, the heater 1050 may be formed of any suitable electrically resistive material. For example, suitable electrically resistive materials include, but are not limited to, metals or metal alloys including titanium, zirconium, tantalum, platinum, nickel, cobalt, chromium, hafnium, niobium, molybdenum, tungsten, tin, gallium, manganese, iron, copper, stainless steel, nichrome, etc. The heater 1050 may also be embodied by, but is not limited to, a metal hot wire, a metal hot plate having a conductive track disposed thereon, a ceramic heating element, etc.

[0128] In other embodiments, heater 1050 is an induction heater. For example, heater 1050 may include a susceptor that generates heat through a magnetic field applied by a coil to heat the aerosol-generating material.

[0129] The user input unit 1060 can receive information input by a user or output information to a user. For example, the user input unit 1060 can be, but is not limited to, a keypad, a dome switch, a touchpad (such as a contact-type capacitance type, a pressure-type resistive film type, an infrared sensing type, a surface ultrasonic conduction type, an integral tension measurement type, or a piezoelectric effect type), a jog wheel, or a jog switch. Although not shown in FIG. 10 , the aerosol generating device 1000 can further include a connection interface such as a USB (universal serial bus) interface to connect to another external device to send and receive information or charge the battery 1040 through the connection interface such as the USB interface.

[0130] The memory 1070 is hardware that stores various data processed within the aerosol generating device 1000 and can store data that has been processed by the control unit 1010 and data to be processed by the control unit 1010. The memory 1070 includes at least one type of recording medium selected from the group consisting of a flash memory type, a hard disk type, a multimedia card micro type, a card-type memory (e.g., SD or XD memory), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, and an optical disk. The memory 1070 can store data related to the operating time of the aerosol generating device 1000, the maximum number of puffs, the current number of puffs, at least one temperature profile, and the user's smoking pattern.

[0131] The communication unit 1080 includes at least one component for communication with other electronic devices. For example, the communication unit 1080 includes a short-range communication unit 1082 and a wireless communication unit 1084.

[0132] The short-range wireless communication unit 1082 includes, but is not limited to, a Bluetooth (registered trademark) communication unit, a BLE (Bluetooth (registered trademark) Low Energy) communication unit, a Near Field Communication unit, a WLAN (Wi-Fi) communication unit, a Zigbee (registered trademark) communication unit, an IrDA (infrared Data Association) communication unit, a WFD (Wi-Fi Direct) communication unit, a UWB (ultra wideband) communication unit, an Ant+ communication unit, etc.

[0133] The wireless communication unit 1084 includes, but is not limited to, a cellular network communication unit, an Internet communication unit, a computer network (e.g., LAN or WAN) communication unit, etc. The wireless communication unit 1084 can also identify and authenticate the aerosol generating device 1000 within the communication network using subscriber information (e.g., International Mobile Subscriber Identity (IMSI)).

[0134] The control unit 1010 can control the overall operation of the aerosol generating device 1000. In one embodiment, the control unit 1010 includes at least one processor. The processor may be embodied as an array of multiple logic gates, or may be embodied by a combination of a general-purpose microprocessor and a memory storing a program executable by the microprocessor. Those skilled in the art will understand that the processor may also be embodied by other forms of hardware.

[0135] The control unit 1010 can control the temperature of the heater 1050 by controlling the supply of power from the battery 1040 to the heater 1050. For example, the control unit 1010 can control the power supply by controlling the switching of a switching element between the battery 1040 and the heater 1050. As another example, a heating direct circuit can control the power supply to the heater 1050 according to a control command from the control unit 1010.

[0136] The control unit 1010 may analyze the results sensed by the sensing unit 1020 and control subsequent processing. For example, the control unit 1010 may control the power supplied to the heater 1050 to start or stop operation of the heater 1050 based on the results sensed by the sensing unit 1020. As another example, the control unit 1010 may control the amount and duration of power supplied to the heater 1050 based on the results sensed by the sensing unit 1020 to heat the heater 1050 to a predetermined temperature or maintain an appropriate temperature.

[0137] The control unit 1010 can control the output unit 1030 based on the result sensed by the sensing unit 1020. For example, if the number of puffs counted through the puff sensor 1026 reaches a predetermined number, the control unit 1010 can notify the user through at least one of the display unit 1032, the haptic unit 1034, and the audio output unit 1036 that the aerosol generating device 1000 will soon be shut down.

[0138] An embodiment may also be embodied in the form of a recording medium containing computer-executable instructions, such as a program module executed by a computer. Computer-readable media are any available media accessible by a computer, including both volatile and nonvolatile media, and both separate and non-separate media. Computer-readable media also include both computer recording media and communication media. Computer recording media include both volatile and non-volatile, separate and non-separate media embodied in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Communication media typically include computer-readable instructions, data structures, other data in a modulated data signal, such as a program module, or other transmission mechanism, and include any information delivery media.

[0139] The above-described embodiments are merely examples, and those skilled in the art will appreciate that various modifications and equivalent embodiments are possible. Therefore, the true scope of protection of the invention should be determined by the claims, and all differences within the scope equivalent to the contents of the claims should be construed as being included in the scope of protection determined by the claims.

Claims

1. In the aerosol generating device, a heater for heating at least a portion of the aerosol product; a puff sensor that detects a user's puff; a processor electrically coupled to the heater and the puff sensor; The processor: Detecting the number of remaining puffs for the aerosol product through the puff sensor; comparing the detected number of residual puffs with a predetermined number of puffs; If the detected number of remaining puffs is less than the predetermined number of puffs, interrupting the supply of power to the heater for a predetermined time; an aerosol generating device that supplies power to the heater so that the temperature of the heater reaches a target temperature corresponding to the number of remaining puffs after the predetermined time has elapsed.

2. The processor: supplying power to the heater based on a first temperature profile when the detected number of remaining puffs is equal to or greater than the predetermined number of puffs; The aerosol generating device according to claim 1 , wherein when the detected number of remaining puffs is less than the predetermined number of puffs, power is supplied to the heater based on a second temperature profile different from the first temperature profile.

3. The aerosol generating device according to claim 2 , wherein the first temperature profile and the second temperature profile are temperature profiles relative to the number of remaining puffs detected by the puff sensor.

4. The aerosol generating device according to claim 2 , wherein the first temperature profile is a temperature profile including a temperature rising section in which the temperature of the heater rises to a critical temperature.

5. The aerosol generating device according to claim 2 , wherein the second temperature profile is a temperature profile in which the target temperature increases as the number of remaining puffs decreases.

6. The processor: If a puff is not detected for a critical time after a puff is detected by the puff sensor, power supply to the heater is interrupted for a predetermined time; The aerosol generating device according to claim 1 , wherein after the predetermined time, power corresponding to a minimum value of a range of power to be supplied to the heater is supplied to the heater.

7. The processor: The aerosol generating device according to claim 1 , wherein the predetermined number of puffs is changed based on an initial temperature rise rate of the heater.

8. The processor: The aerosol generating device according to claim 7 , wherein when the initial temperature rise rate exceeds a critical rate range, the predetermined number of puffs is changed to a number of puffs lower than the predetermined number of puffs.

9. The processor: The aerosol generating device according to claim 7 , wherein when the initial temperature rise rate is below a critical rate range, the predetermined number of puffs is changed to a number of puffs higher than the predetermined number of puffs.

10. 1. A method of operating an aerosol generating device, comprising: Detecting the number of remaining puffs for the aerosol product through a puff sensor that senses a user's puffs; comparing the detected number of residual puffs with a predetermined number of puffs; If the detected number of remaining puffs is less than the predetermined number of puffs, interrupting power supply to a heater that heats at least a portion of the aerosol product for a predetermined time; and after the predetermined time has elapsed, supplying power to the heater so that the temperature of the heater reaches a target temperature corresponding to the number of remaining puffs.

11. The method for operating an aerosol generating device according to claim 10, further comprising the steps of: supplying power to the heater based on a first temperature profile when the detected number of remaining puffs is equal to or greater than the predetermined number of puffs; and supplying power to the heater based on a second temperature profile different from the first temperature profile when the detected number of remaining puffs is less than the predetermined number of puffs.

12. If a puff is not detected for a critical time after a puff is detected by the puff sensor, interrupting power supply to the heater for a predetermined time; The method of claim 10, further comprising: supplying, to the heater, power corresponding to a minimum value of a range of power to be supplied to the heater after the predetermined time.

13. The method for operating the aerosol generating device according to claim 10, further comprising the step of changing the predetermined number of puffs based on an initial heating rate of the heater.

14. The method for operating an aerosol generating device according to claim 13, further comprising changing the predetermined number of puffs to a number of puffs lower than the predetermined number of puffs when the initial heating rate exceeds a critical rate range.

15. The method for operating an aerosol generating device according to claim 13, further comprising changing the predetermined number of puffs to a number of puffs higher than the predetermined number of puffs when the initial heating rate is below a critical rate range.

Images