Electronic smoking devices

Abstract

To provide an aromatic vapor generation device and an electronic smoking device.SOLUTION: An electronic smoking device comprises: a liquid reservoir for storing liquid; a wick for extracting the liquid from the liquid reservoir, a heater for heating the liquid extracted from the liquid reservoir in order to generate vapor; a sensor wound around the wick, the sensor being configured to convert the liquid extracted from the reservoir into the vapor; and an electronic controller configured to detect the amount of reduction of the liquid in the liquid reservoir on the basis of an electric resistance between the heater and the sensor.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to scented vapor generating devices and electronic smoking devices. [Background technology]

[0002] Electronic smoking devices, such as e-cigarettes, are gaining popularity and acceptance as an alternative to traditional cigarettes.

[0003] An electronic cigarette typically includes a flavored smoke generator and electronic circuitry contained within an elongated (or long) housing adapted for finger holding and including a mouthpiece defining an airway connecting the flavored smoke generator to the user, such that flavored smoke vapor generated in response to inhalation by the user is delivered to the user through the mouthpiece.

[0004] The electronic circuit typically includes an electric heater that operates to heat a medium moistened with a flavored liquid. This medium is usually a liquid-compatible or liquid-retaining medium such as cotton or fiberglass. The flavored liquid, also known as e-juice or e-liquid, is usually a solution containing organic substances such as propylene glycol (PG), vegetable glycerin (VG), polyethylene glycol 400 (PEG 400) mixed with flavor concentrates, nicotine concentrate, or mixtures thereof.

[0005] A flavored smoke generator typically includes a cartridge and an atomizer. The cartridge is typically a small plastic, glass, or metal container with openings at both ends that is adapted to function as both a liquid reservoir for holding a flavored liquid and a mouthpiece. The atomizer is provided for vaporizing the flavored liquid and therefore typically includes a small heater filament and a wicking material that draws the flavored liquid from the cartridge reservoir into contact with or proximity to the heater filament. When the electronic cigarette is activated, the heater filament heats the wicking material, which is moistened with the liquid, generating flavored smoke that is delivered to the user.

[0006] When a cartridge and atomizer are integrated, the resulting device is known as a cartomizer. Summary of the Invention [Problem to be solved by the invention]

[0007] Although no paper or tobacco is actually burned during the operation of an e-cigarette, the absence or insufficient presence of flavored liquid can cause overheating of the flavored smoke generator, which can be harmful and may result in unknown or unclear health effects or complications. [Means for solving the problem]

[0008] The present invention provides an electronic smoking device comprising a liquid reservoir configured to store liquid, a wick configured to draw liquid from the liquid reservoir, a heater configured to heat the liquid drawn from the liquid reservoir to generate vapor, a sensor wrapped around the wick, the sensor configured to convert the liquid drawn from the reservoir into vapor, and an electronic controller configured to detect a decrease in the amount of liquid in the liquid reservoir based on the electrical resistance between the heater and the sensor.

[0009] In the electronic smoking device of the present invention, the heater may have an electric heating coil wound around the wick.

[0010] In the electronic smoking device of the present invention, the sensor may be a conductor, and the sensor and the heater may be configured to operate as parallel transducers.

[0011] In the electronic smoking device of the present invention, both ends of the sensor may each define a first terminal.

[0012] In the electronic smoking device of the present invention, the electronic controller may be connected to both ends of the sensor via the first terminals.

[0013] In the electronic smoking device of the present invention, both ends of the heater may each define a second terminal.

[0014] In the electronic smoking device of the present invention, the electronic controller may be connected to both ends of the heater via the second terminals.

[0015] In the electronic smoking device of the present invention, the electronic controller may further include a control circuit configured to detect a decrease in the amount of liquid in the liquid reservoir based on the electrical resistance of the wick.

[0016] In the electronic smoking device of the present invention, the electronic controller may be configured to control the electrical output to the heater for generating the vapor based on the amount of liquid reduced in the liquid reservoir.

[0017] In the electronic smoking device of the present invention, the electronic controller may be configured to reduce the electrical output to the coil and generate a warning signal, or to both reduce the electrical output to the coil and generate a warning signal, in response to detecting a decrease in liquid in the liquid reservoir.

[0018] In the electronic smoking device of the present invention, the liquid reservoir, the wick, and the heater may be part of a cartomizer of the electronic smoking device, and the electronic controller may be part of a main body of the electronic smoking device. The cartomizer is detachably connected to the main body.

[0019] The electronic smoking device of the present invention may further include a visual indicator disposed within the main body, which may include an LED indicator.

[0020] The present invention also provides a scented vapor generating device comprising: a liquid reservoir configured to store a scented liquid; an electric heating coil disposed in the liquid reservoir and configured to heat the scented liquid; and a sensor including a resistance wire disposed in the liquid reservoir, the sensor configured to detect a decrease in the amount of scented liquid in the liquid reservoir based on the electrical resistance between the electric heating coil and the resistance wire.

[0021] For example, the scented liquid may include propylene glycol (PG), vegetable glycerin (VG), polyethylene glycol 400 (PEG400), partial combinations thereof, or combinations thereof.

[0022] Alternatively, the scented liquid may include propylene glycol (PG), vegetable glycerin (VG), polyethylene glycol 400 (PEG400), other organic solvents, glycol-based solvents, glycerin-based solvents, partial combinations thereof, or combinations thereof.

[0023] Preferably, the scented steam generating device of the present invention may further include a resistance measuring circuit connected to the heating coil and the resistance wire and configured to measure the electrical resistance between the heating coil and the resistance wire.

[0024] The scented vapor generating device of the present invention may be, for example, a cartomizer configured to be detachably connected to the main body of an electronic cigarette device.

[0025] Preferably, the scented vapor generating device of the present invention may further comprise an electronic controller configured to control the operation of the electric heating coil for heating the scented liquid.

[0026] The electronic controller may be configured to reduce electrical output to the heating coil, or generate a warning signal, or both reduce electrical output to the heating coil and generate a warning signal in response to detecting a decrease in the scented liquid in the liquid reservoir.

[0027] The electronic controller is configured to determine whether the scented liquid in the liquid reservoir is at or above an operational threshold.

[0028] Preferably, the electronic controller is configured to control the operation of the electric heating coil to either stop or heat the scented liquid at a limited output, or to heat the scented liquid at rated output, based on a decrease in scented liquid in the liquid reservoir.

[0029] Preferably, the liquid reservoir, the electric heating coil and the sensor are housed in a cartomizer of the electronic cigarette device, the electronic controller is housed in a main body of the electronic cigarette device, and the cartomizer is detachably connected to the main body. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of a scented steam generator according to the present disclosure. [Figure 2] FIG. 2 is a schematic diagram illustrating the assembly of the liquid-holding medium and electric heater of the scented vapor generator shown in FIG. [Figure 3] FIG. 3 is a schematic diagram of an electronic cigarette incorporating the flavored vapor generator of FIG. [Figure 4] FIG. 4 is a functional block diagram of the electronic cigarette of FIG. [Figure 5] FIG. 5 is a schematic diagram depicting features of an example scented steam generator. [Figure 6] FIG. 6 is a schematic diagram depicting features of an example scented steam generator. [Figure 7] FIG. 7 is a schematic diagram depicting features of an example scented steam generator. DETAILED DESCRIPTION OF THE INVENTION

[0031] The present disclosure will now be described by way of non-limiting example with reference to the accompanying drawings, in which:

[0032] The scented steam generator 100 depicted in FIG. 1 includes an air inlet at an air inlet end 110, a scented steam outlet at a scented steam outlet end 120, and a body 130 interconnecting the air inlet end 110 and the scented steam outlet end 120. The body 130 is generally cylindrical and includes a rigid housing extending axially between the air inlet end 110 and the scented steam outlet end 120. Supported on the body are an electric heater including electrical wires 152, an exposed or bare liquid retention device 154 including a plurality of liquid retention wicks 155, and a wetness sensor 156. The body is attached to a base 140 that defines the air inlet end. The body's rigid housing includes an outer peripheral wall 132 and an inner peripheral wall 134 surrounded by the outer peripheral wall 132. The space between the outer and inner peripheral walls collectively define a first hollow compartment 136 adapted to hold a supply of flavored liquid, the hollow compartment 136 defining a reservoir for storing a quantity of flavored liquid for dispensing into an exposed or bare liquid holding device.

[0033] The interior space enclosed by the inner peripheral wall 134 defines a second hollow compartment 138 within the body 130. This hollow compartment 138 defines a hollow passage channel through which scented vapor generated by operation of the heater passes and exits the steam generator 100. The inner and outer peripheral walls are generally cylindrical and coaxial or concentric such that the first hollow compartment forms a generally circular chamber surrounding the second hollow compartment.

[0034] The exposed liquid retention device 154 extends between a first liquid outlet on a first side wall of the reservoir 136 and a second liquid outlet on a second side wall of the reservoir 136 opposite the first liquid outlet. The liquid retention device 154 comprises a plurality of wicks that protrude across the second hollow section 138. The wicks are formed from bundles of fibrous liquid retention material 155, such as fiberglass yarns, and scented liquid stored in the reservoir is guided to travel along the wicks from the first and / or second liquid outlets and become exposed within the second hollow section 138.

[0035] The exemplary flavored vapor generator 100 is a cartomizer packaged in the form of a disposable cartridge. The cartridge is adapted to be attached to the body of an electronic cigarette to facilitate the simulation of a smoking action. The air inlet end is for connecting to the body of the electronic cigarette, and the base portion includes a "snap-on" or threaded end for securing to the body of the electronic cigarette. The portion of the cartridge near the flavored vapor outlet end 120 is adapted for a mouthpiece adapted for lip contact by a user.

[0036] The electric heater is coupled to the portion of the wick exposed within and throughout the second hollow section 138. As depicted in FIG. 2, the electric heater includes a heating wire 152 wound into multiple windings. The multiple windings formed by the heating wire are attached to a bundle of glass fibers 155 that collectively define an exemplary bare liquid retention device 154. This exemplary liquid retention wick includes a plurality of glass fibers twisted into strands (or tufts) of glass fibers. The glass fibers are filled with the scented liquid by wicking the scented liquid from the reservoir 136. The assembly including the wound heating filament and the glass fiber strands is supported on the body and extends in a bridge manner across the second hollow section. The assembly including the glass fiber bundle and the wound heating filament is elongated and extends axially. The axial end of the assembly penetrates or protrudes into the second hollow compartment and provides a tab to ensure a continuous supply of scented liquid for repeated actuation within a scented liquid reservoir formed within the second hollow compartment.

[0037] The assembly, including the wound heating filament and fiberglass strands, is supported on the body by a rigid wire frame 158 extending from the base 140. The rigid wire frame 158 is made of rigid conductive wire, such as copper- or nickel-plated iron wire. The wire extends from the base, extends upward within the first hollow section 136, makes a right-angle bend at an elevation above the base, passes through the inner periphery wall to enter the second hollow section 138, extends across the second hollow section at approximately the same elevation, passes through the inner periphery wall again, re-enters the first hollow section 136 at a location approximately diametrically opposite the point where it originally exited the first hollow section, and then makes a right-angle bend downward to return to the base. Both ends of the resistance wire extend beyond the base 140 to define contact terminals T3 and T4 accessible from the side of the base 140 distal to the second hollow section. To avoid short circuits and to facilitate external terminal connections, the base may be made of an insulating material, or both end portions of the resistance wire may be insulated.

[0038] The assembly, including the wound heating filament and stranded glass wire, is positioned so that the exposed portion of the resistance wire is embedded within the stranded glass wire, thereby isolating the exposed portion of the resistance wire from the heater filament. In one example, the filament is wound into multiple windings around the stranded glass wire, and the resistance wire is positioned on the axis of the coil formed by the windings of the filament. The approximately centered positioning of the resistance wire within the coil promotes more uniform resistance measurements within the liquid-retaining material and reduces local variations. Because this portion of the heater filament is wound around the stranded glass wire and the stranded glass wire is held on a portion of the rigid wire that extends across the second hollow section, the rigid frame of the rigid resistance wire provides support to enhance the strength and reliability of the heating filament. The contact terminals T1 and T2 of the electric heater are also accessible from the same side of the base 140 as the contact terminals T3 and T4.

[0039] A flavored liquid, such as a solution containing an organic substance such as propylene glycol (PG), vegetable glycerin (VG), polyethylene glycol 400 (PEG 400) mixed with a flavor concentrate, nicotine concentrate, or a mixture thereof, is stored inside the first hollow compartment. Storage of the flavored liquid inside the first hollow compartment is achieved by filling the first hollow compartment with a liquid-absorbent material, such as cotton or other fabric material, that is moistened with the flavored liquid. This arrangement provides a continuous supply of flavored liquid while reducing sealing requirements. For example, this arrangement reduces excessive leakage of flavored liquid at the junction where the assembly containing the heating filament and the stranded glass wire enters and exits the first hollow compartment.

[0040] During normal use, as the electric heater operates and generates heat, the scented liquid stored within the assembly is vaporized. After vaporization occurs, the stranded fiberglass wires, by capillary or similar effect, carry the scented liquid away and replenish it from the scented liquid reservoir. This process repeats until the scented liquid within the reservoir is depleted. If the assembly is further heated in a situation where the reservoir is depleted, the assembly may heat to a significant temperature or overheat. Such overheating may be harmful and may cause unknown, undesirable side effects or complications.

[0041] To mitigate such harmful conditions, the wetness or dampness of the fiberglass strands is monitored. In devising a scheme for determining the wetness or dampness of the fiberglass strands, using the information to determine whether the reservoir or strands are depleted, it is noted that the types of flavored liquids commonly used to simulate smoking through electrical heating are oily or oil-based, but can still exhibit some degree of conductivity. In this example, the wetness or dampness is monitored by measuring the resistance between a wound heater filament and a section of rigid resistance wire embedded within the fiberglass strands.

[0042] Examples of resistance measurements taken using a Fluke™ 189 meter for various terminal combinations between the contact terminals on the heater (one of T1 and T2) and the contact terminals on the sensor (one of T3 and T4) are shown in Table 1 below.

[0043] [Table 1]

[0044] In Table 1 above, the designation "OL" means over limit, and the specified limit was 40MΩ. Wet state means that the fiberglass strands are completely wetted with flavored liquid such as e-juice or e-liquid.

[0045] In view of the above, it is noted that the resistance between the sensor terminals and the heater terminals can be used as an indication of whether the fiberglass strands are wet or dry. It will be appreciated that the terms "wet" or "dry" in this context refer to scented liquids, particularly scented liquids for producing a simulated smoke effect by electrical heating, and are unrelated to wetting with water.

[0046] To take advantage of this phenomenon, a threshold resistance between the sensor terminals and the heater terminals may be selected as an indication of wetness or dryness of the liquid retaining material. For example, a resistance value above 3 MΩ measured between the sensor terminals and the heater terminals may be selected as a threshold operating resistance below which the fiberglass strands are wet enough to be operational, and above which the fiberglass strands are dry and unsuitable for operation.

[0047] If a higher measurement margin is to be tolerated, the threshold non-operating resistance indicating inoperable dryness may be set to 4 MΩ, 5 MΩ, 10 MΩ, 20 MΩ, 30 MΩ, or even higher due to the rapid increase in resistance of the fiberglass strands as they become dry of e-juice.

[0048] Alternatively, the threshold operating resistance, indicating a suitable wetness level for operation, may be set to a value lower than 6MΩ, 5MΩ, 4MΩ, 3MΩ or 2.5MΩ without loss of generality.

[0049] An example of an electronic cigarette 10, depicted in FIG. 3, includes a first elongated (or long) body 12 and a cartomizer cartridge 100 of the present disclosure attached to one axial end of the first elongated body. The first elongated body and the rigid housing have the same outer shape and lateral dimensions so that the electronic cigarette appears as a single unit. The first elongated body defines an air inlet, an air outlet, and a hole interconnecting the air inlet and the air outlet. The air outlet end of the first elongated body includes mechanical coupling means for mechanically coupling with the air inlet end of the cartomizer, complementary to the means on the air inlet end of the cartomizer. A control circuit 14, a battery 16, and a visual indicator 18, such as an LED indicator, are located within the elongated body. Contact terminals are located on the air outlet end of the first elongated body to facilitate contact between heater terminals T1, T2 and sensor terminals T3, T4 and their counterparts within the control circuit. The control circuit includes an operating circuit for activating the electric heater and a decision circuit arranged to stop or limit power supply to the electric heater upon detecting that a wet or moist condition in the fiberglass strands is unsuitable for heating operation. As indicated above and without loss of generality, the control circuit may determine whether the wet or moist condition is suitable for operation in relation to a resistance measured between the sensor terminals and the heater terminals.

[0050] FIG. 5 illustrates another example of a flavored vapor generator 200 according to the present disclosure. This example of a flavored vapor generator is a modified version of the example of the flavored vapor generator 100, in which a non-conductive or insulating wick is directly used as the sensing device. In this example, the output terminals of a sensor 254 are connected to the longitudinal ends of a wick 255. Because the resistance of the wick varies substantially depending on whether the wick is filled with flavored liquid and whether the wick is completely or partially filled with flavored liquid, information about such resistance characteristics can be used to determine the operation of the electronic cigarette. In this example, other features are the same as those of the flavored vapor generator 100, and therefore, descriptions of these other features are included in the disclosure by reference to numerals increased by 100.

[0051] 6 illustrates another example scented vapor generator 300 according to the present disclosure. This example scented vapor generator is a modification of example scented vapor generator 100, in which the conductor forming the sensor's sensing device acts as a second converter for converting the scented liquid into scented vapor. In this example, conductor 356 forming the sensor's sensing device is wound around the wick and can operate as a parallel converter. In this example, other features are the same as those of scented vapor generator 100, and therefore, descriptions of these other features are included in the disclosure by reference to the numerals increased by 200.

[0052] Another example of a scented vapor generator 400, depicted in FIG. 7, is a modified version of another example of a scented vapor generator 300. In this example, both the heater 450 and the sensor 456 are immersed inside the reservoir 436. Because both the heater 450 and the sensor 456 are immersed inside the reservoir 436, no wick is required to draw the scented liquid from the reservoir. During operation, the scented liquid stored inside the reservoir is heated to generate scented vapor, which passes through a hollow passage channel to the scented vapor outlet. Other features are the same as those of the scented vapor generator 300, and therefore, descriptions of these other features are incorporated into the disclosure by reference to numerals increased by 100. The sensor heater may be selectively activated to increase the operating power of the transducer, if necessary.

[0053] The scented vapor generating apparatus disclosed herein includes a liquid retention device including a fibrous liquid-retaining material for retaining a scented liquid, a liquid reservoir for supplying the scented liquid to the fibrous liquid-retaining material of the liquid retention device, a converter operable with electrical power to convert the scented liquid on the fibrous liquid-retaining material into scented vapor, and a sensor positioned to provide information regarding the amount or density (or concentration) of the scented liquid retained on the fibrous liquid-retaining material.

[0054] In some embodiments, the liquid retention device and the liquid reservoir are combined or integrated, eliminating the need for a fibrous liquid retention material, and both the transducer and the sensor are immersed in a bath of scented liquid. In such embodiments, the scented vapor generating device includes a liquid retention device that also serves as a liquid reservoir for storing scented liquid, a transducer operable with electrical power to convert the stored scented liquid into scented vapor, and a sensor, the sensor and the sensor being immersed in the bath of scented liquid. In such embodiments, the sensor and the transducer are electrically connected via the bath. Electrical properties such as resistance and capacitance between the transducer and the sensor change or fluctuate according to the level of the bath or the relative immersion of the transducer and the sensor. By detecting electrical properties resulting from the separation of the transducer and the sensor via the scented liquid as a connecting medium, information regarding wetting or whether the residual level of the scented liquid has dropped to a minimum threshold can be obtained and utilized. If capacitance is to be measured in combination with measuring resistance, circuit portion 17 of Figure 4 would be modified as a circuit for measuring resistance and capacitance, respectively, or, without loss of generality, as a circuit for measuring capacitance. Furthermore, although circuit portion 15 of Figure 4 is described as a heater driver, this circuit may also be referred to as a "transducer driver" where appropriate.

[0055] Disclosed herein is an electronic smoking device including a flavored vapor generating device, wherein an electronic controller controls the operation of a transducer to generate a flavored smoke vapor by reference to a sensor output.

[0056] Also disclosed is a scented vapor generator for use in an electronic smoking device, the scented vapor generator comprising: a housing; a liquid-retaining material filled, moistened, or immersed with a scented liquid and received within the housing; an electric heater for heating the liquid-retaining material to generate scented vapor; and a sensor for monitoring the moist or wet state of the liquid-retaining material and for providing a signal to facilitate determining whether the moist or wet state of the liquid-retaining material corresponds to a depletion or near-depletion state of the scented liquid in the liquid-retaining material.

[0057] Further disclosed is a scented steam generator, wherein the housing defines a first hollow compartment in which the scented liquid is stored, and a second compartment defining an air inlet, a scented air outlet, and an air passage interconnecting the air inlet and the air outlet, and an assembly comprising the liquid retaining material and the electric heater extends from the first hollow compartment into the air passage so that air coming from the air inlet due to suction at the air outlet encounters the assembly before reaching the scented air outlet.

[0058] In some embodiments, the device is a cartomizer that is removably attachable to the main body of the electronic smoking device, and the liquid contained within the liquid reservoir facilitates the flavored vapor generating device operating as a flavored source of smoke for the electronic smoking device.

[0059] The sensor may be adapted to monitor the moist or wet state of the liquid-holding material and to provide a signal to facilitate determining whether the moist or wet state of the liquid-holding material corresponds to a depletion or near-depletion state of the scented liquid in the liquid-holding material.

[0060] The inclusion of a wetness sensor within a flavored vapor generator for use in an electronic smoking device is advantageous because information regarding wetness or dryness in the liquid retaining material can be used to facilitate operational control of the electronic cigarette.

[0061] The fibrous liquid retention material may be made of cotton, fiberglass, or other woven material capable of carrying and retaining flavored liquids, such as liquids known as e-juice or e-liquid, whether or not they contain nicotine.

[0062] The fibrous liquid-retaining material may be formed as a thread, yarn or braid, with or without twist.

[0063] The scented liquid may be an oily substance, and the sensor includes a probe for detecting an electrical resistance state within the liquid-retaining material. The scented liquid may be primarily organic-based, such as glycol- or glycerin-based, and the sensor monitors an electrical property, such as conductivity or resistance, within or across the liquid-retaining material during operation to facilitate determining whether the liquid-retaining material is wet or dry.

[0064] Oil-based flavored liquids are known to be generally non-conductive, but their slight conductivity is nevertheless useful in providing a simple, fast, and informative wetness measurement to facilitate operational control of electronic smoking.

[0065] The electric heater may comprise a heating element attached to the liquid-holding material and held in contact with the liquid-holding material to facilitate contact heating to generate the scented vapor, and the sensor comprises a probe wire portion embedded within the liquid-holding material.

[0066] The heating element may comprise a heating filament wound on the liquid-retaining material to form a plurality of windings, and the probe wire portion is surrounded by and spaced apart from the windings.

[0067] The liquid retention material may comprise a bundle of absorbent fibers or fiber strands extending collectively in a first direction to define a wicking direction, and the heating element is wound around the first direction to define a winding core containing the liquid retention material.

[0068] The housing may be made of metal and defines a first hollow compartment in which the scented liquid is stored, and a second compartment defining an air inlet, a scented air outlet, and an air passage interconnecting the air inlet and the air outlet, and an assembly comprising the liquid retaining material and the electric heater extends from the first hollow compartment into the air passage so that air coming from the air inlet due to suction at the air outlet encounters the assembly before reaching the scented air outlet.

[0069] In some embodiments, a second hollow compartment is enclosed within the first hollow compartment, and both ends of the assembly protrude into the first hollow compartment to convey the flavored liquid into the liquid retaining material.

[0070] The assembly may be suspended on opposite sides of the first hollow section to form a bridge extending across the second hollow section.

[0071] A scented liquid may be stored in the second hollow compartment and rests on an absorbent material such as cotton for wicking (capillary transport) to the liquid retaining material within the second hollow compartment.

[0072] The liquid retainer and heater assembly may extend in a direction generally transverse to the direction of airflow from the air inlet to the scented vapour outlet during normal operation.

[0073] The generator may be arranged such that an electrical resistance between the sensor and the electric heater that is below a threshold operating resistance indicates that the liquid retaining material is in a moist or wet condition suitable for operation.

[0074] The threshold operating resistance may be set to 5MΩ, 4MΩ, 3MΩ, 2MΩ or lower.

[0075] The generator may be arranged such that an electrical resistance between the sensor and the electric heater that exceeds a threshold non-operating resistance indicates a moist or wet condition of the liquid retaining material that is not suitable for operation.

[0076] The threshold non-operating resistance may be set to 10 MΩ, 20 MΩ, 30 MΩ or higher.

[0077] The scented steam generator may be in the form of a cartridge, with power terminals for powering the electric heater and sensor terminals for obtaining wetness information accessible from the outside of the housing.

[0078] The scented steam generator may be a cartomizer.

[0079] An electronic cigarette is disclosed that includes a control device and a flavored vapor generator, wherein the control device activates an electric heater upon determining whether the flavored vapor generator is in a wet or moist state suitable for normal operation.

[0080] The control device may be configured to not operate the electric heater to heat the scented steam generator to generate scented smoke when it determines that the moist or wet state of the scented steam generator corresponds to a state where the scented liquid in the liquid retaining material is depleted or near depletion.

[0081] The control device may be arranged to not operate the electric heater to heat the scented vapor generator to generate scented smoke upon determining that the resistance between the sensor and the electric heater is higher than a threshold non-operating resistance.

[0082] The electronic smoking system comprises a scented vapor generating device according to the present invention and an electronic controller, which controls the operation of the converter to generate scented smoke vapor by referring to the sensor output.

[0083] Although an electric heater is provided as an example of a converter for converting a scented liquid into a scented vapor, the converter need not be limited to a heater and can be other atomizing devices, such as an ultrasonic atomizer, without loss of generality.

[0084] While examples are provided herein to illustrate the principles and embodiments of the disclosure, it should be appreciated that the examples are merely for reference and are not intended to limit the scope of the disclosure. For example, while the cartomizers disclosed herein are in the form of disposable cartridges, it should be appreciated that the cartomizers may be integrally formed with electronic cigarettes without loss of generality. For example, while the present disclosure is described with reference to exemplary flavored liquids known as e-juice or e-liquids, which are typically solutions containing organic substances such as propylene glycol (PG), vegetable glycerin (VG), polyethylene glycol 400 (PEG 400) mixed with flavor concentrates, nicotine concentrates, or mixtures thereof, it should be appreciated that the examples used are merely illustrative, and that other types of liquids known from time to time that are suitable for the operation of electronic cigarettes may also be used. [Explanation of symbols]

[0085] 10: Electronic smoking devices 12: Main body 14: Control circuit (electronic controller) 15: Heater driver (electronic controller) 17: Circuit (electronic controller) 100:Cartomizer 152: Electric heating coil 300: Steam generator 350: Heater 356: Conductors (sensor sensing devices)

Claims

1. a liquid reservoir configured to store a liquid; a wick configured to draw liquid from the liquid reservoir; a heater configured to heat the liquid withdrawn from the liquid reservoir to generate vapor; a sensor wrapped around the wick, the sensor configured to convert liquid drawn from the reservoir into vapor; and an electronic controller configured to detect a decrease in the amount of liquid in the liquid reservoir based on an electrical resistance between the heater and the sensor.

2. 2. The electronic smoking system of claim 1, wherein the heater comprises an electric heating coil wrapped around the wick.

3. 3. The electronic smoking device according to claim 1, wherein the sensor is a conductor, and the sensor and the heater operate as a parallel converter.

4. 2. The electronic smoking system of claim 1, wherein each end of the sensor defines a first terminal.

5. 5. The electronic smoking device of claim 4, wherein the electronic controller is connected to both ends of the sensor via the first terminals.

6. 2. The electronic smoking system of claim 1, wherein both ends of the heater define second terminals.

7. 7. The electronic smoking system of claim 6, wherein the electronic controller is connected to both ends of the heater via the second terminals.

8. 2. The electronic smoking device of claim 1, wherein the electronic controller further comprises a control circuit configured to detect a decrease in the amount of liquid in the liquid reservoir based on the electrical resistance of the wick.

9. 2. The electronic smoking device of claim 1, wherein the electronic controller is configured to control the electrical output to the heater for generating the vapor based on the amount of liquid reduced in the liquid reservoir.

10. 2. The electronic smoking device of claim 1, wherein the electronic controller is configured to reduce the electrical output to the coil, generate a warning signal, or both reduce the electrical output to the coil and generate a warning signal in response to detecting a decrease in liquid in the liquid reservoir.

11. the liquid reservoir, the wick, and the heater are part of a cartomizer of the electronic smoking device; The electronic controller is a part of the main body of the electronic smoking device; 2. The electronic smoking device according to claim 1, wherein the cartomizer is detachably connected to the main body.

12. a visual indicator disposed within the body; 12. The electronic smoking system of claim 11, wherein the visual indicator comprises an LED indicator.

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