Abstract:
An electronic cigarette or similar vaporization devices include a liquid which is vaporized or atomized in an atomizer. An e-liquid detection system can verify that the e-liquid is acceptable for use in the device. The e-liquid detection system may detect one or more indicators, and/or physical or chemical properties of the e-liquid. The e-liquid detection system may also measure the e-liquid level in the device.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    An electronic cigarette or similar vaporization device includes a liquid, referred to as e-liquid, which is vaporized or atomized in an atomizer. Using an e-liquid that is not suitable for the vaporization device may cause overheating or underheating of the e-liquid, or other improper operations. Thus, there is a need to prevent use of unsuitable e-liquids in the device. 
       SUMMARY OF THE INVENTION 
       [0002]    An electronic cigarette or similar vaporization device has an e-liquid detection system which can verify that the e-liquid is acceptable for use in the device. The system may detect one or more indicators, and/or physical or chemical properties of the e-liquid. The system may also measure the e-liquid level in the device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]    In the drawings, the same reference number indicates the same element in each of the views. 
           [0004]      FIG. 1  shows a section view (a) and a top view (b) of an example of a liquid storage. 
           [0005]      FIG. 2  shows a section view of an example of a fluorescent e-liquid detection system. 
           [0006]      FIG. 3  shows a section view (a) and a top view (b) of another example of a fluorescent e-liquid detection system. 
           [0007]      FIG. 4  shows a section view (a) and a top view (b) of another example of a fluorescent e-liquid detection system. 
           [0008]      FIG. 5  shows a section view (a) and a top view (b) of an example of the capacitor e-liquid detection system. 
           [0009]      FIG. 6  shows a section view of an example of an electronic cigarette comprising an e-liquid detection system. 
           [0010]      FIG. 7  shows a section view (a) and a top view (b) of another example of the capacitor e-liquid detection system. 
           [0011]      FIG. 8  shows a section view (a) of another examples of the capacitor e-liquid detection system; and a section view (b) and a top view (c) of yet another examples of the capacitor e-liquid detection system. 
           [0012]      FIG. 9  shows a section view (a) and a top view (b) of another example of the capacitor e-liquid detection system. 
           [0013]      FIG. 10  shows a section view of an example of an ultrasound e-liquid detection system and the ultrasonic path. 
           [0014]      FIG. 11  provides a section view of an example of the pressure e-liquid detection system. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    A vaporization device has an e-liquid detection system, a liquid storage element containing an e-liquid, and an atomizer. The vaporization device may be an electronic cigarette, electronic pipe, or electronic cigar, or any device that vaporizes a liquid for inhalation. The liquid storage may be at least part of an e-liquid cartridge or a so-called e-liquid cartomizer, clearomizer or tankomizer. 
         [0016]    The-liquid detection system may verify that the e-liquid in the vaporization device is suitable for use in the device and prevent unauthorized refilling and/or modifications of the e-liquid by the user. The atomizer may be configured to shut down if the e-liquid detection system does not provide a signal of acceptance. In certain embodiments, the e-liquid detection system may also determine the e-liquid level in the liquid storage. 
         [0017]    The liquid storage element stores a majority amount (e.g., about 95% to about 99.9%, or about 95% to about 99%) of the e-liquid contained in the device. Thus, measuring the e-liquid level in the liquid storage is substantially equivalent to measuring the e-liquid level in the device. As used herein, the term “about” followed by a numeral means a range of the numeral ±5% or 10% of the numeral. 
         [0018]    The liquid storage element may take any shape as desired. For example, the liquid storage element may be a tube, tank, bottle or container containing the e-liquid. The liquid storage element may contain an absorbent or porous filler material. 
         [0019]      FIG. 1  shows a section view (a) and a top view (b) of an example of a liquid storage element  10  having a through hole  30  extending along the direction of the air flow  5 . In certain embodiments, the liquid storage  10  has a first wall  15  and a second wall  25 , with the through hole  30  in the first wall  15 . The first and second walls  15  and  25  together form a compartment  35  that holds the e-liquid. In certain embodiments, the liquid storage element may have an absorbent material, optionally forming the through hole  30 , confined by the second wall  25 , with no first wall  15  needed. In other embodiments, the liquid storage element is hollow or open, and contains no solid materials. 
         [0020]    The entire inner wall of the liquid storage element, or one or more parts of it may be polished, or coated with a layer (e.g. film, coating, etc.) reflective to light and/or sonic signals. For example, the sidewall and the bottom of the liquid storage element may be polished or coated with a reflective layer. 
         [0000]    Fluorescent e-liquid Detection System 
         [0021]    One aspect of the invention relates to a vaporization device comprising a liquid storage element storing an e-liquid, a fluorescent e-liquid detection system, and an atomizer. The fluorescent e-liquid detection system has a light source and a light detector. The e-liquid contains at least one product indicator. The light source provides a first light that is absorbed by the product indicator, with the product indicator emitting a second light that is detected by the light detector. For a known product indicator, the wavelengths of the first and the second lights are also known. The absence of the second light of the second pre-determined wavelength indicates the absence of the pre-determined product indicator. Thus, the atomizer may be configured to shut down when the light detector does not receive the second light of the second pre-determined wavelength. 
         [0022]    Examples of product indicators are fluorophores that emit light of longer wavelengths (fluorescent light) than the light absorbed (absorbent light). Preferred product indicators only emit fluorescent light when being exposed to the absorbent lights. Examples of fluorophores are, compounds having a conjugated system (e.g. single bond-double bond conjugate system(s), aromatic system(s) further conjugated with double bond(s) and/or other aromatic system(s)). Quinine may be used as a product indicator. Quinine is inexpensive, highly sensitive, and safe for human consumption. It is included in the World Health Organization&#39;s list of essential medicines, a list of the most important medications needed in a basic health system. Other examples of fluorophores suitable for product indicators include Alexa Fluor dyes (e.g. Alexa Fluor 488 and 514), BODIPY dyes (e.g. BODIPY FL, BODIPY R6G, 8-phenyl BODIPY), cyanine dyes (e.g. Cy 5.5, and Cy 7), cypate, fluorescein, indocyanine green (ICG), Oregon green dyes (e.g., Oregon green 488, Oregon green 514), rhodamine dyes (e.g. rhodamine 110, rhodamine 6G, and rhodamine X), rhodol, TAMRA (5-(and-6)-carboxytetramethylrhodamine), Texas red, and xanthene derivatives (e.g. Tokyo green). 
         [0023]    The concentration of the product indicator(s) in a suitable e-liquid is advantageously as low as possible. In e-liquids suitable for use in an electronic cigarette, the concentration of product indicator may be at or close to the threshold of detection. The e-liquid will then be suitable or useable as is, but become non-suitable if diluted, thereby preventing use of unapproved e-liquid mixtures. Most of the fluorophores may be used at a very lower concentration without recognizable toxic effect. 
         [0024]    Examples of light sources are UV LED, or any light source that provides the suitable absorbent light. As used herein, the wavelength specified for an absorbent light for a fluorophore is the wavelength at the maximum absorption. The fluorophore may be properly excited by lights in a wavelength range of the maximum absorption ±10 nm, ±20 nm, ±50 nm, ±100 nm, or ±200 nm. For example, the maximum absorption wavelength for quinine is about 560 nm. A light source in the wavelength of 550 nm to 570 nm, 5400 nm to 580 nm, or 510 nm to 610 nm will be suitable to excite quinine. The maximum absorption wavelength of some other fluorophore examples is about 346 nm to about 782 nm for the Alexa Fluor dyes (e.g. about 495 nm for Alexa Fluor 488, about 517 nm for Alexa Fluor 514), about 500 nm to about 646 nm for BODIPY dyes (e.g. about 503 for BODIPY FL, about 528 for BODIPY R6G, and about 524 for 8-phenyl BODIPY), about 489 nm to about 743 nm for cyanine dyes (e.g. about 675 nm for Cy 5.5, and about 743 nm for Cy 7), about 494 nm for fluorescein, about 600 nm to about 900 nm for ICG (e.g., about 800 nm), about 490 nm to about 515 nm for Oregon green dyes (e.g., about 496 nm for Oregon green 488, about 511 nm for Oregon green 514), about 528 nm to about 586 nm for rhodamine dyes (e.g. about 498 nm for rhodamine 110, about 530 nm for rhodamine 6G, and about 585 nm for rhodamine X), about 492 nm for rhodol, about 557 nm for TAMRA, about 589 nm for Texas red, and about 491 nm for xanthene derivatives such as Tokyo green. 
         [0025]    Examples of light detectors are photodetectors having a color filter to filter only the indicator fluorescent light to the detector (e.g., green (about 460 nm) for quinine; about 442 nm to about 805 nm for the Alexa Fluor dyes (e.g. about 519 nm for Alexa Fluor 488, about 542 nm for Alexa Fluor 514); about 506 nm to about 660 nm for BODIPY dyes (e.g. about 512 for BODIPY FL, about 550 for BODIPY R6G, and about 540 for 8-phenyl BODIPY); about 506 nm to about 767 nm for cyanine dyes (e.g. about 694 nm for Cy 5.5, and about 767 nm for Cy 7); about 524 nm for fluorescein; about 750 to about 950 nm for ICG (e.g., about 810 nm and about 830 nm); about 520 nm to about 535 nm for Oregon green dyes (e.g., about 524 nm for Oregon green 488, about 530 nm for Oregon green 514); about 553 nm to about 605 nm for rhodamine dyes (e.g. about 520 nm for rhodamine 110, about 566 nm for rhodamine 6G, and about 597 nm for rhodamine X); about 516 nm for rhodol; about 583 nm for TAMRA; about 615 nm for Texas red; and about 510 nm for xanthene derivatives such as Tokyo green. 
         [0026]    The light source may be configured to flash at a first puff to verify the e-liquid as a suitable e-liquid. If the e-liquid does not fluoresce, the vaporization device may shut down. 
         [0027]    The light source may be programmed to flash at programmed intervals to determine the e-liquid level according to the intensity of fluorescent light the light detector detects, and the refractive index of the e-liquid. A table or plot of the parameter (e.g. refractive index) detected v. remaining e-liquid level may be obtained for a specific type of e-liquid and e-liquid detection system. Then, the table or plot may be used to determine the corresponding e-liquid level for a measured parameter. 
         [0028]    The results may be displayed on the vaporization device to indicate the e-liquid level. For example, an LED showing different colors may be used to indicate the e-liquid level (e.g. red: empty; green: full; amber: medium); or a digital display may be used to show the e-liquid level. 
         [0029]      FIG. 2  shows a section view of an example of a fluorescent e-liquid detection system for a liquid storage  10 . A prism  110  is placed on one end of the liquid storage  10 . Alternatively, the prism  110  may be omitted if the inner surface of said end of the liquid storage  10  reflects light sufficiently well. A light source (e.g. a LED)  130  and a light detector  140  are placed in proximity to the other end of the liquid storage  10 . The e-liquid in the liquid storage  10  comprises a product indicator. The product indicator absorbs the light provided by the light source  130  and emits a fluorescent light received by the light detector  140 , as shown by the light path  120  in  FIG. 2 . 
         [0030]      FIG. 3  shows a section view (a) and a top view (b) of another example of a fluorescent e-liquid detection system. The inside of the liquid storage  10  is polished and may reflect light as shown by the light path  120  in the top view of the fluorescent e-liquid detection system ( FIG. 3 b   ). The light source (e.g. a LED)  130  and the light detector  140  are placed on the inside wall of the liquid storage  10 , such that the light detector  140  receives the fluorescent light the product indicator emits upon absorbance of the light provided by the light source  130 . 
         [0031]      FIG. 4  shows a section view (a) and a top view (b) of another example of a fluorescent e-liquid detection system for a liquid storage  10 , wherein the liquid storage  10  has a through hole  30  as described supra (see  FIG. 1 ). The inside of the liquid storage  10  is polished and may reflect light as shown by the light path  120  in the top view of the fluorescent e-liquid detection system ( FIG. 4 b   ). The light source (e.g. a LED)  130  and the light detector  140  are placed on the inside wall of the liquid storage  10 , such that the light detector  140  receives the fluorescent light the product indicator emits upon absorbance of the light provided by the light source  130 . 
         [0032]    The light source  130  and the light detector  140  are shown to be on about the opposite side of the liquid storage  10  in  FIGS. 3 and 4 . However, the light detector may be placed at any position (e.g., other positions shown in  FIG. 5 ) in the liquid storage  10  as long as it can receive the fluorescent light. 
         [0033]      FIG. 6  shows a section view of an electronic cigarette  1  having a tubular housing  100 , with a liquid storage element  10 , an e-liquid detection system  50 , and an atomizer  60  in the housing  100 . The e-liquid detection system  50  includes a light source  130  positioned to emit light into the liquid storage element  10  and a light detector  140  positioned to detect light emitted from the light source  130  into the liquid storage element  10 . A controller  70  in the housing  100  electrically is connected to the e-liquid detection system  50  and to the atomizer  60 , with the controller  70  allowing activation of the atomizer  60  based on a signal from the liquid detection system  50 . 
         [0034]    The light detector  140  in the electronic cigarette  1  is positioned to detect light reflected off of a surface of the liquid storage element  10  (e.g., as shown in  FIGS. 3 b  and 4 b   ). 
         [0035]    The light detector  140  in the electronic cigarette  1  is positioned to detect light passing through the liquid storage element  10  (e.g., as shown in  FIGS. 3 b  and 4 b   ). 
         [0000]    Capacitor e-liquid Detection System 
         [0036]    Another aspect of the invention relates to a vaporization device comprising a liquid storage storing an e-liquid, a capacitor e-liquid detection system, and an atomizer. 
         [0037]    The capacitor e-liquid detection system comprises a first conductor and a second conductor. The first and second conductors are at least partially parallel to each other, and configured to form a capacitor circuit having a capacitance. The first and second conductors extend from one end of the liquid storage substantially to the other end thereof through the longitude direction thereof. The first and second conductors are configured such that a substantial amount (e.g., about 90% to about 99.9%, about 95% to about 99.9%, about 90% to about 95%, or about 95% to about 99%) of the e-liquid in the liquid storage is between the first and second conductors. Thus, the permittivity of the capacitor relates to a substantial amount (e.g., about 90% to about 99.9%, about 95% to about 99.9%, about 90% to about 95%, about 95% to about 99%) of the e-liquid remained in the liquid storage. 
         [0038]    The liquid storage  10  may be a tube as shown in  FIG. 7 .  FIG. 7  shows a section view (a) and a top view (b) of an example of the capacitor e-liquid detection system. The first conductor  210  and the second conductor  220  may be conductive plates (e.g. metal plates). The first and second conductors  210  and  220  are configured to be as close to the outside wall  45  of the liquid storage  10  as possible to maximize the amount of e-liquid positioned between the first and the second conductors  210  and  220 . The first and the second conductors  210  and  220  are at least partially parallel to each other, e.g., about 80% to about 99.9%, about 90% to about 99.9%, about 95% to about 99.9% of the area of the first conductor  210  is parallel to the second conductor  220 . The first and the second conductors  210  and  220  are configured to form a capacitor circuit having a capacitance. One end of the first and the second conductors  210  and  220  are electronically connected to the PCB  20  (outside of the liquid storage  10 ) via a first lead  215  and a second lead  225 , respectively. The other end of the first and the second conductors  210  and  220  are not electronically connected. 
         [0039]      FIG. 8( a )  shows a section view of another example of the capacitor e-liquid detection system disclosed herein. At least a portion of the outside wall  45  of the liquid storage  10  is conductive (e.g. metal) and at least partially parallel to the first conductor  210 . Thus, the portion of the outside wall  45  may serve as the second conductor  220 . One end of the first and the second conductors  210  and  220  may be electrically connected to the PCB  20  (outside of the liquid storage  10 ) via a first lead  215  and a second lead  225 , respectively. The other end of the first and the second conductors  210  and  220  are not electrically connected. 
         [0040]      FIG. 8( b )  shows a section view and  FIG. 8( c )  shows a top view of another example of the capacitor e-liquid detection system disclosed herein. Two separate conductive (e.g. metal) portions of the outside wall  45  of the liquid storage  10  that are insulate from each other, are at least partially parallel to each other. Thus, the two separate conductive portions of the outside wall  45  may serve as the first and the second conductors  210  and  220 , respectively. The first and the second conductors  210  and  220  are configured to form a capacitor circuit having a capacitance, as described supra. One end of the first and the second conductors  210  and  220  may be electronically connected to the PCB  20  (outside of the liquid storage  10 ) via a first lead  215  and a second lead  225 , respectively. The other end of the first and the second conductors  210  and  220  are not electronically connected. 
         [0041]    The first and/or the second conductors may adopt various widths. The parallel portion of the first and second conductors  210  and  220  may be narrow or broad. The first and/or second conductors  210  and  220  may be relatively broad and extend along partial of or substantially (e.g., about) the whole circumference of the wall(s) of the liquid storage  10  (e.g., see  FIG. 9  for conductors surrounding the circumference of the walls of the liquid storage  10 ). 
         [0042]    The liquid storage may comprise a through hole  30  as described supra ( FIG. 1 ). The liquid storage  10  comprises a first wall  15  and a second wall  25 . 
         [0043]      FIG. 9  shows a section view (a) and a top view (b) of an example of the capacitor e-liquid detection system disclosed herein. The first and the second conductors  210  and  220  are conductive plates surrounding the first wall  15  and the second wall  25  of the liquid storage  10 , respectively. Alternatively, the first and the second conductors  210  and  220  may only extend along part of the circumferences of the first and the second walls  15  and  25 , respectively, as long as the conductors  210  and  220  are at least partially parallel to each other. The first and the second conductors  210  and  220  are configured to form a capacitor circuit having a capacitance, as described supra. One end of the first and the second conductors  210  and  220  may be electrically connected to the PCB  20  (outside of the liquid storage  10 ) via a first lead  215  and a second lead  225 , respectively. The other end of the first and the second conductors  210  and  220  are not electrically connected. 
         [0044]    In another embodiment, the first wall  15  is conductive (e.g., metal) and may serve as the first conductor  210 . In another embodiment, the second wall  25  is conductive (e.g., metal) and may serve as the second conductor  220 . In another embodiment, both of the first and the second walls  15  and  25  are conductive (e.g., metal) and serve as the first and the second conductors  210  and  220 , respectively. 
         [0045]    For a capacitor having a media (e.g., e-liquid) between the first and second conductors thereof, the permittivity of the capacitor depends on the amount and the composition of the liquid. The more sensitive the permittivity changes over the liquid amount, the more accurate the capacitor e-liquid detection system may determine whether the e-liquid is a suitable product, and/or the remaining e-liquid level. Substances having higher permittivity may increase the sensitivity of permittivity changes to change of the liquid amount. Preferred examples include, without limitation, glycerol. 
         [0046]    An e-liquid comprising compatible high permittivity substances may be used to identify suitable product and determine the remaining e-liquid level. 
         [0047]    A table or plot of the parameter (e.g. permittivity) detected v. remaining e-liquid level may be obtained for a specific type of e-liquid and e-liquid detection system. Then the table or plot may be used to determine the corresponding e-liquid level for a measured parameter. 
         [0048]    In certain embodiments, the capacitor e-liquid detection system may be configured to measure the permittivity at programmed intervals to determine the permittivity change pattern of the e-liquid. The vaporization device may shut down if the permittivity change pattern measured is significantly different (e.g. smaller) from what is expected from using a suitable product. The results of remaining e-liquid level may be displayed on the surface of the vaporization device as described supra. 
         [0000]    Ultrasound e-liquid Detection System 
         [0049]    An ultrasound e-liquid detection system may be used. The ultrasound e-liquid detection system has an ultrasound emitter and an ultrasound detector. When an ultrasound signal is applied to a liquid, the resonant frequency received depends on the amount of the liquid in the container. When a sonar signal is applied to the liquid storage, the resonant frequency received reflects the remaining e-liquid level in the liquid storage element. 
         [0050]      FIG. 10  shows a section view of an example of an ultrasound e-liquid detection system and the ultrasonic path. The ultrasound emitter  330  and the ultrasound detector  340  are placed in proximity to one end of the liquid storage  10 . The inner surface of the other end of the liquid storage  10  is reflective to sonar signals. The ultrasound detector  340  is positioned to receive the sonar signal after it travels through the liquid storage  10 , via the ultrasonic path  320 . 
         [0051]    A table or plot of the parameter (e.g. sonar signals) detected v. remaining e-liquid level may be obtained for a specific type of e-liquid and e-liquid detection system. Then the table or plot may be used to determine the corresponding e-liquid level for a measured parameter. In certain embodiments, the ultrasound e-liquid detection system may be configured to measure the resonant frequency at programmed intervals to determine the resonant frequency of the e-liquid. The results of remaining e-liquid level may be displayed on the surface of the vaporization device as described supra. 
         [0000]    Pressure e-liquid Detection System 
         [0052]    Another aspect of the invention relates to a vaporization device comprising a liquid storage storing an e-liquid, a pressure e-liquid detection system, and an atomizer. The pressure e-liquid detection system comprises a pressure sensor positioned at one end of the liquid storage that is closer to the direction of gravity. The weight of the liquid storage will change based on the e-liquid level therein. Because the pressure measured by the pressure sensor relates to the weight of the liquid storage, measuring the pressure may determine the remaining e-liquid level in the liquid storage.  FIG. 11  provides a section view of an example of the pressure e-liquid detection system. The pressure sensor  410  is positioned in proximity to one end of the liquid storage  10  that is close to the PCB  20 . 
         [0053]    A table or plot of the parameter (e.g. pressure) detected v. remaining e-liquid level may be obtained for a specific type of e-liquid and e-liquid detection system. Then the table or plot may be used to determine the corresponding e-liquid level for a measured parameter. In certain embodiments, the pressure e-liquid detection system may be configured to measure the pressure at programmed intervals to determine the pressure of the e-liquid. The results of remaining e-liquid level may be displayed on the surface of the vaporization device as described supra.