E-Vaping Device Comprising an Optical Device

Description

FIELD OF THE INVENTION

The invention relates to the technical field of an e-vaping device comprising a recess for receiving an aerosol generating heat-not-burn consumable article.

BACKGROUND OF THE INVENTION

It is interesting to add a new functionality of automatic detection of used heated tobacco sticks (HTS) into an HTS vaping device. This functionality is seldom implemented in other heated tobacco devices despite the need to protect user health, improving device usability, inter alia including not wasting battery energy heating used sticks, and providing a consistent sensory delivery. So, there is a need for a functionality enabling an HTS vaping device to detect if an inserted HTS has been already used or not, in a simple and efficient way. This need is not limited to HTS vaping devices, but also exists for other aerosol generating devices using any type of aerosol generating heat-not-burn consumable articles.

A first problem is to avoid heating of an aerosol generating heat-not-burn consumable article already used (meaning needing to be replaced by a new one).

A solution to this first problem is to detect, at an external surface of the aerosol generating heat-not-burn consumable article, a change of reflectivity, preferably a change of color on an external surface of the aerosol generating heat-not-burn consumable article or optionally a change of chromaticity of a tag fixed on external surface of the aerosol generating heat-not-burn consumable article, by an optical device located close to an external surface of the aerosol generating heat-not-burn consumable article.

In some embodiments of the invention, a light beam is emitted by an optical source, goes through an optical window, is reflected at external surface of the aerosol generating heat-not-burn consumable article, goes back through the optical window, is detected by an optical detector.

According to a prior art, for example disclosed by patent applications KR102319257, WO2021141259, CN112955038, WO 2021 194541, EP 3831223, or U.S. Ser. No. 10/869,499, such a solution to this first problem is disclosed.

However, none of these solutions works fully properly since the optical window of the optical device used to detect and/or assess this change of reflectivity, preferably this change of color on external surface of the aerosol generating heat-not-burn consumable article or this change of chromaticity of a tag fixed on external surface of the aerosol generating heat-not-burn consumable article, is or easily becomes dirty with dust or dirt from condensed matter coming from the aerosol generating heat-not-burn consumable article heating. There is a second problem of making or keeping clean the optical window of the optical device, although presence of dust and condensed matter of dirt coming from heating of successive heat sticks in the e-vaping device.

SUMMARY OF THE INVENTION

The object of the present invention is to alleviate at least partly the above mentioned drawbacks.

More particularly, the invention aims to make or keep clean the optical window of the optical device, although presence of dust and dirt coming from heating of successive aerosol generating heat-not-burn consumable articles, for example heat sticks, in the e-vaping device, by cleaning the optical window of the optical device at each time the aerosol generating heat-not-burn consumable article or the heat stick is replaced, and especially by using the removal of old aerosol generating heat-not-burn consumable article and the insertion of new aerosol generating heat-not-burn consumable article to perform such cleaning of the optical window of the optical device, via a brushing of the optical window of the optical device automatically and mechanically performed by the removal of old aerosol generating heat-not-burn consumable article and/or the insertion of new aerosol generating heat-not-burn consumable article themselves.

Therefore, the invention proposes an optical window of the optical device which is protruding within the aerosol generating heat-not-burn consumable article recess (also called cavity, chamber or oven) of the e-vaping device so as to be brushed by the move of the aerosol generating heat-not-burn consumable article itself, either when removed and/or when inserted.

This way, the cleaning of the optical window of the optical device can be performed while reducing the risk of damaging the aerosol generating heat-not-burn consumable article, either upon removal (after use) or upon insertion (before use) of an aerosol generating heat-not-burn consumable article, what would lead to additional dust or dirt within the recess and what may also degrade the integrity of the new aerosol generating heat-not-burn consumable article.

This object is achieved with an e-vaping device comprising: a recess for receiving an aerosol generating heat-not-burn consumable article, a heater disposed close to or against said recess so as to heat said aerosol generating heat-not-burn consumable article, an optical device: which is disposed in a hole of a wall of said recess so as to detect a change of reflectivity at external surface of said aerosol generating heat-not-burn consumable article corresponding to a change of said aerosol generating heat-not-burn consumable article going: from new state, where said aerosol generating heat-not-burn consumable article has not yet been heated by said heater, to used state, where said aerosol generating heat-not-burn consumable article has been heated so much by said heater that said aerosol generating heat-not-burn consumable article is used and should be replaced by a new aerosol generating heat-not-burn consumable article, and which comprises: an optical window, an optical source, an optical detector, which are disposed relatively to one another so that a light beam can successively: be emitted by said optical source, go through said optical window, be reflected by said external surface of said aerosol generating heat-not-burn consumable article, go back through said optical window, be received by said optical detector, wherein said optical window protrudes into said recess so as to be brushed by said aerosol generating heat-not-burn consumable article, upon insertion into said recess and/or upon removal from said recess, of said aerosol generating heat-not-burn consumable article, wherein said optical window comprises, on each side of said optical window, along longitudinal direction of said recess, a beveled extension so as to make progressive said insertion and said removal of said aerosol generating heat-not-burn consumable article.

This aerosol generating heat-not-burn consumable article can be a tobacco heat stick or a heat stick generating a flavor different from tobacco.

Preferred embodiments comprise one or more of the following features, which can be taken separately or together, either in partial combination or in full combination.

Preferably, at least half of said optical window protrudes into said recess so as to be brushed by said aerosol generating heat-not-burn consumable article upon insertion and/or upon removal of said aerosol generating heat-not-burn consumable article.

Hence, the cleaning of the optical window of the optical device is improved.

Said optical window protrudes entirely into said recess so as to be brushed by said aerosol generating heat-not-burn consumable article upon insertion and/or upon removal of said aerosol generating heat-not-burn consumable article.

Preferably, said optical window protrudes into said recess by at least 0.5 mm, or by at least 1 mm, or by at least 2 mm, or by at least 3 mm.

Hence, the cleaning of the optical window of the optical device is improved.

Preferably, said beveled extension presents an angle ranging from 15 degrees to 45 degrees, or an angle ranging from 20 degrees to 40 degrees, or an angle which is about 30 degrees. The angle is defined with respect to the longitudinal direction of the recess of the oven. The beveled extension can be the beveled extension can be straight, or S shaped or can have the shape of a quarter of cosine ramp, so as to have a smoother profile.

Hence, the cleaning of the optical window of the optical device can be performed while reducing the risk of damaging the aerosol generating heat-not-burn consumable article, either upon removal of the old aerosol generating heat-not-burn consumable article or upon insertion of the new aerosol generating heat-not-burn consumable article, what would lead to additional dust or dirt within the recess (for both used and new aerosol generating heat-not-burn consumable articles) and what would also degrade working of the new aerosol generating heat-not-burn consumable article.

Preferably, said optical device is at least partly inserted within a wall of said recess, preferably within a peripheral wall of said recess.

Hence, robustness of fixing of said optical device within recess of e-vaping device is improved.

Preferably, said recess forms an elongate cavity and includes a closed bottom at one longitudinal end and an opening at the other longitudinal end by which said aerosol generating heat-not-burn consumable article can be inserted into said e-vaping device, said optical device is disposed closer to said closed bottom than to said opening, preferably closer to said closed bottom than to middle position between said closed bottom and said opening, said optical device is preferably away from said closed bottom by a distance of at least 5 mm.

Hence, the efficiency of detecting and/or assessing the change of reflectivity, preferably the change of color on external surface of the aerosol generating heat-not-burn consumable article or the change of chromaticity of a tag fixed on external surface of the aerosol generating heat-not-burn consumable article, is improved, since the end of aerosol generating heat-not-burn consumable article which is used first is indeed the part of the aerosol generating heat-not-burn consumable article which is detected and/or assessed.

Preferably, said optical device is disposed so as to detect a change of color of external surface of said aerosol generating heat-not-burn consumable article corresponding to a change of said aerosol generating heat-not-burn consumable article going: from new state, where said aerosol generating heat-not-burn consumable article has not yet been heated by said heater, to used state, where said aerosol generating heat-not-burn consumable article has been heated so much by said heater that said aerosol generating heat-not-burn consumable article is used and should be replaced by a new aerosol generating heat-not-burn consumable article.

Hence, the detection is made simpler.

Preferably, said optical device is disposed so as to detect a change or reflectivity or a change of color of a tag located on external surface of said aerosol generating heat-not-burn consumable article corresponding to a change of said aerosol generating heat-not-burn consumable article going: from new state, where said aerosol generating heat-not-burn consumable article has not yet been heated by said heater, to used state, where said aerosol generating heat-not-burn consumable article has been heated so much by said heater that said aerosol generating heat-not-burn consumable article is used and should be replaced by a new aerosol generating heat-not-burn consumable article.

Hence, the detection is made more efficient.

Preferably, said optical device faces a peripheral wall of said external surface of said aerosol generating heat-not-burn consumable article.

Preferably, the e-vaping device also comprises: either an alarm emitting a warning when said optical device has detected said change of reflectivity at external surface of said aerosol generating heat-not-burn consumable article, and/or a security impeding said heater to heat further or again said aerosol generating heat-not-burn consumable article.

Hence, the result of the detection is used to avoid or to impede reuse of an already used heat stick.

Preferably, said optical source emits a single light beam, said optical detector detects said change of reflectivity at external surface of said aerosol generating heat-not-burn consumable article by detecting a variation in absolute intensity of received light from said single light beam reflection.

Hence, the structure of the optical device is made simpler.

Preferably, the e-vaping device comprises: two of said optical sources emitting respectively simultaneously two light beams of respectively different chromatic ranges, two of said detectors detecting said change of reflectivity at external surface of said aerosol generating heat-not-burn consumable article by respectively detecting a variation in relative intensities of light received respectively from said two light beams.

Hence, the efficiency of the optical device is improved.

Preferably, the e-vaping device comprises: two of said optical sources emitting respectively alternatively two light beams of respectively different chromatic ranges, said single detector detecting said change of reflectivity at external surface of said aerosol generating heat-not-burn consumable article by detecting a variation in relative intensities of light received alternatively from said two light beams.

Hence, the structure of the optical device is made simpler and the efficiency of the optical device is improved.

Further features and advantages of the invention will appear from the following description of embodiments of the invention, given as non-limiting examples, with reference to the accompanying drawings listed hereunder.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of tobacco heat stick reflectivity and color change between before (top of FIG. 1) and after (bottom of FIG. 1) the heat stick has been heated and thereby used, thereby illustrating the property of the heat stick used for the detection of heat stick reflectivity and color change.

FIG. 2 shows an example of an optical device used to detect the color change of the heat stick according to an embodiment of the invention.

FIG. 3 shows an example of integration within oven recess of an optical device used to detect the color change of the heat stick according to an embodiment of the invention.

FIG. 4 shows an example of slight compression of heat stick by the optical window of the optical device to assure contact and cleaning of the optical window by the heat stick move (upon removal and/or upon insertion).

FIG. 5 shows an example of optical device working with a time-division multiplexing of the received light on the photodetector from the two light sources blue and red with a white or yellow target.

DETAILED DESCRIPTION OF THE INVENTION

The aerosol generating heat-not-burn consumable article will be considered in the following description as a tobacco heat stick, but following description remains valid for any other aerosol generating heat-not-burn consumable article.

Optical sources and optical detectors or photodetectors are used. Preferably, the wavelength range is in the optical spectrum, but other wavelengths could be used as well if the change of reflectivity of the external surface of the aerosol generating heat-not-burn consumable article or tobacco heat stick is sufficient to be reliably detected by the detector.

FIG. 1 shows an example of a difference of reflectivity and color between a tobacco heat stick before use (top of FIG. 1) and after (bottom of FIG. 1) use with a heat-not-burn aerosol generating device.

On top of FIG. 1, there is a new tobacco heat stick 1 which has a cylindric shape and which presents an external surface 10 with a cylindric shape with a circular cross-section. Another cross section could be used instead, like for example a square cross-section. The external surface 10 comprises a mouthpiece part 11 and an aerosol substrate part 12. The color of the whole external surface 10, including both mouthpiece part 11 and aerosol substrate part 12, is for instance white.

On bottom of FIG. 1, there is used tobacco heat stick 1 which also has a cylindric shape and which presents an external surface 10 with a cylindric shape with a circular cross-section. Another cross section could be used instead, like for example a square cross-section. The external surface 10 comprises a mouthpiece part 11 and an aerosol substrate part 13. The color of most of the whole external surface 10, including its mouthpiece part 11, is still white. However, the color of its aerosol substrate part 13, is not white anymore white but has become yellow or brown. Anyway, the color of the external surface of the bottom part of a used tobacco heat stick is different from the color of the external surface of the aerosol substrate part of a new, never heated, tobacco heat stick. This change of color of part of the external surface 10 of the tobacco heat stick 1, from white to yellow, or even from white to brown, corresponds to a change of state for the tobacco heat stick 1 which has gone from a new state, where this tobacco heat stick 1 has not yet been heated by a heater of an oven of an e-vaping device, to a used state, where this tobacco heat stick 1 has been heated so much by the heater that this tobacco heat stick 1 is used and should be replaced by a new tobacco heat stick 1.

FIG. 2 shows an example of an optical device used to detect the color change of a heat stick according to an embodiment of the invention.

The optical device 2 includes a support 20, at least one optical source 21, one optical detector 22, an optical window 24 at least partially transparent to optical light, a bottom beveled extension 23 on one side of the optical window 24, a top beveled extension 25 on the other side of the optical window 24.

This optical device 2 works in a simple way: the optical source 21 emits or sends light which goes through the optical window 24, is partially reflected by the external surface 10 of the tobacco heat stick 1 (not shown on FIG. 2), comes back through the optical window 24, is detected by the optical detector 22.

Depending on the intensity of detected light by the optical detector 22, and/or compared to the intensity of the emitted light by the optical source 21, this intensity of detected light varying according to the change of color leading to a change of reflectivity of the external surface 10 of the tobacco heat stick 1. The optical device 2 can then assess whether the tobacco heat stick 1 is a new one or on the contrary is a used one which has already been heated and is thus unproper for new use.

The optical device 2 may be connected to a controller of an aerosol generating device (such as a processor, microcontroller, or equivalent) configured to assess, based on the measured intensity of the reflected light from an external surface of a heat stick whether the latter is a new one or on the contrary has already been used and heated. The controller may further be configured to issue a warning signal, for example a haptic signal (vibration or light) or a sound and/or to a mechanism precluding the heater of the aerosol generating device comprising the optical device 2 to be powered.

FIG. 3 shows an example of integration of an optical device 2 as represented in FIG. 2 and described before in an oven 7 of an aerosol generating or e-vaping device 5 according to an embodiment of the invention.

The e-vaping device 5 comprises, inter alia, a rechargeable battery 50, an oven 7 including a heater 4 and a recess 3, an optical device 2 partly protruding within the recess 3, a lid 51 for allowing, respectively preventing access to the recess 3.

The recess 3 is adapted for receiving a tobacco heat stick 1 (not represented on FIG. 3). The recess 3 is roughly a hollow cylinder, which is limited by a peripheral wall 30, which has an opening 31 through which the tobacco heat stick 1 can be inserted within the recess 3 and can be removed therefrom, and which has a closed bottom 32 against which closed bottom 32. X is the longitudinal direction of the recess 3. A heater 4 is arranged about the recess 3 for, in use of the e-vaping device, heating a heat stick inserted in the recess 3 to generate an inhalable aerosol or vapor. The heater 4 may be of various types commonly found in e-vaping devices. In an embodiment, it may, for example, be a resistive heater disposed against the peripheral wall 30 of recess 3, so as to conductively heat the recess wall 30 and thereby a tobacco heat stick 1 inserted therein. In another embodiment, the heater 4 may comprise an induction coil wrapped around the peripheral wall 30 of the recess 3 to heat a tobacco heat stick in the recess 3, either by inductively heating a susceptor element (comprising a metal or a metallic alloy and/or a semiconductor such as silicon carbide, carbon or graphite) provided inside the heat stick aerosol substrate part or indirectly by inductively heating the peripheral wall 30 of the recess 3, which then comprises a susceptor material such as a metal or metallic alloy and/or a semiconductor such as silicon carbide, carbon or graphite).

The optical device 2 is arranged within an opening in the peripheral wall 30 of recess 3, and protrudes into the recess 3 from this peripheral wall 30.

When a tobacco heat stick 1 (not represented on FIG. 3) is inserted within the recess 3 through the opening 31, it is pushed by a user towards the closed bottom 32 of recess 3. During insertion, the substrate part 12 of the tobacco heat stick will abut first against the top beveled extension 25 and, by effect of the beveled surface be slightly and softly compressed between the beveled extension 25 and the recess wall 30 opposite the optical device 2. As the heat stick passes the beveled extension 25 and continues towards the closed end 32 of the recess, its external surface brushes smoothly the optical window 24 of the optical device 2, thereby cleaning it automatically until and end of the aerosol substrate part of the heat stick abuts against closed bottom 32 of recess 3.

The optical device 2 and e-vaping device are configured to probe and detect whether a heat stick inserted into the recess 3 is new, thus can be used for a satisfying vaping session or, to the contrary, if it was already heated during a previous vaping session and is improper for further usage.

This probing of the inserted heat stick can be carried out either dynamically as the heat stick is inserted into the recess and brushes the optical window 24 as it moves towards the closed end 32 of the recess or statically when the heat stick abuts said closed end 32. The probing of the heat stick is however carried out likewise in any case. It consist essentially in emitting a light beam from the optical source 21 of the optical device 2 through the cleaned optical window 24, the emitted light beam being then reflected by an external surface of the substrate part 12 of the tobacco heat stick 1 in the recess 3 and passing through the optical window 24 again towards the optical detector 22.

The controller of the e-vaping device then measures the light intensity of the reflected light beam and compares it against a threshold value, or range of light intensity values, stored in a memory of the e-vaping device for example, said threshold value being determined either by factory setting or calibration of the e-vaping device by a user.

In practice, the threshold value or threshold range of values corresponds to the light intensity value or the range of light intensity values corresponding to that of a reflected light beam from an outer surface of a new heat stick having never been heated before. That way, if the reflected light intensity detected and measured by the optical device 2 differs from the threshold value stored in the memory of the e-vaping device, this indicates that the heat stick inserted in the recess 3 is not new and should not be used (and heated) again.

In a preferred example, the threshold light intensity value may correspond to a heat stick outer color being white. By opposition, the light intensity value measured from a reflected light beam from a used or heated state may correspond to that of an outer color of the heat stick being yellow or brown.

If the measured reflected light intensity corresponds to the stored threshold value, then the heat stick inserted in the recess is a new one and the heater 4 of the vaping device 2 can be powered on for heating the substrate part 12 of the heat stick at least to generate an inhalable aerosol or vapor. On the contrary, if the reflected light intensity measured correspond to a yellow or even brown external surface of substrate part 12 of heat tobacco stick 1 (typically lower than the threshold value or outside threshold range of values) then the inserted tobacco heat stick 1 is an old and used one which would then be precluded from being heated by heater 4 of oven 7.

After a vaping session, a used tobacco heat stick 1 (not represented on FIG. 3) will be removed from the recess 3 through the opening 31 to be discarded by the user. This used tobacco heat stick 1 will move away from the closed bottom 32 of recess 3 towards the opening 31 of recess 3. During travel of the used heat stick towards opening 31, the heated substrate part 13 of tobacco heat stick 1 will slide against the bottom beveled extension 23 of the optical device 2, so as to avoid that heated substrate part 13 of tobacco heat stick 1 breaks off and remains in the closed bottom 32 of recess 3, and then brush smoothly the optical window 24 thereby cleaning this optical window 24 automatically during its removal from recess 3, finally being progressively released by the top beveled extension 25, for the heat stick 1 to be freely removed from the recess 3.

If an old and used tobacco heat stick 1 (not represented on FIG. 3) is inserted again within the recess 3 through the opening 31, this tobacco heat stick 1 will be probed by the optical device 2 after insertion and the intensity of the reflected light detected by optical detector 22 will differ from the threshold value as previously described, indicating a pre-heated stick in the recess. The controller of the e-vaping device then prevents power to be delivered to the heater 4.

The optical device 2 protrudes from the peripheral wall 30 by a distance d within the recess 3 which has a diameter D (or a width D if its cross section is not circular). The distance d is at least 0.5 mm, or at least 1 mm, preferably at least 2 mm, more preferably at least 3 mm, advantageously less than 5 mm. The ratio d/D ranges advantageously from 5% to 15%.

FIG. 4 shows an example of slight compression of heat stick by the optical window of the optical device to assure contact and cleaning of the optical window by the heat stick move (upon removal and/or upon insertion).

On FIG. 4, the protrusion of the optical device 2 from the peripheral wall 30 within recess 3 can be seen. Advantageously, only the optical window 24, as well as the beveled extensions top 25 and bottom 23, protrude from the peripheral wall 30 within recess 3, whereas the support 20, the optical source 21 and the optical detector 22, all remain implemented within the peripheral wall 30 of recess 3.

The protrusion of the optical window 24, as well as the beveled extensions top 25 and bottom 23, from the peripheral wall 30 within recess 3, not only allows for cleaning of optical window 24 automatically, during and by, tobacco heat stick 1 insertion into recess 3 and removal from recess 3, but also it allows for a proper and correct positioning of the bottom part 12 of tobacco heat stick 1 which abuts well against the optical window 24, without any space left between the optical window 24 and the external surface 10 of the bottom part 12 of tobacco heat stick 1.

FIG. 5 shows an example of optical device working with a time-division multiplexing of the received light on the photodetector from the two light sources blue and red with a white or yellow target.

The color change detection could rely on the absolute light intensity received by the optical detector 22, that is to say when it is over a said calibrated threshold, the tobacco heat stick 1 is considered new, whereas when it is under this calibrated threshold, the tobacco heat stick 1 is considered used, and in that case, the e-vaping device would not turn on (thereby precluding the old and already used tobacco heat stick 1 form being again heated in the oven of the e-vaping device) and/or rise a warning to the user.

As an alternative implementation, hereby implemented on FIG. 5, there could be two optical sources 21 instead of only one optical source, for instance one blue optical source and one red optical source, and the change of color from white to yellow or to brown is detected by the optical detector 22 via the change of ratio between reflected blue light and reflected red light.

In particular, with a white target 71, corresponding to a white external surface of a new tobacco heat stick 1, the two colors are going to be equally reflected, as can be seen on FIG. 5, where the reflected red light 61 is at the same intensity as the reflected blue light 62.

But, on the contrary, when the target 72 turns yellow or brown, corresponding to a yellow or brown external surface of an old and already used tobacco heat stick 1, the blue radiation will be more absorbed than the red one, thereby resulting in a stronger reflected red intensity 63 detected on the optical detector 22, as compared with a weaker reflected blue intensity 64 detected on the optical detector 22.

Advantageously, in order not to duplicate the optical detector 22 and the need of adding optics (e.g., filter or prism) to separate the two wavelengths, the two radiations, red and blue, can be timed alternatively, using time-division multiplexing (either from two light sources or from a multi-wavelengths light source as an Red Green Blue LED).

The invention has been described with reference to preferred embodiments. However, many variations are possible within the scope of the invention.