U.S. patent application number 12/460101 was filed with the patent office on 2009-11-12 for system for detecting a container or contents of the container.
Invention is credited to Imre J. Dancs, Eric B. Gach, Dennis W. Gruber, Jeffrey L. Harwig, John A. Heathcock.
Application Number | 20090278554 12/460101 |
Document ID | / |
Family ID | 36650200 |
Filed Date | 2009-11-12 |
United States Patent
Application |
20090278554 |
Kind Code |
A1 |
Dancs; Imre J. ; et
al. |
November 12, 2009 |
System for Detecting a Container or Contents of the Container
Abstract
A system for detecting a container or contents of the container.
The system includes a diffuser for retaining the container, where
the container is configured to hold an active material therein and
may include a wick extending therefrom. The system further includes
a sensor positioned to detect, for example, the container retained
in the diffuser and/or the contents of the container retained in
the diffuser.
Inventors: |
Dancs; Imre J.; (Greenfield,
WI) ; Harwig; Jeffrey L.; (New Berlin, WI) ;
Heathcock; John A.; (Racine, WI) ; Gruber; Dennis
W.; (Arlington Heights, IL) ; Gach; Eric B.;
(Mount Prospect, IL) |
Correspondence
Address: |
S.C. JOHNSON & SON, INC.
1525 HOWE STREET
RACINE
WI
53403-2236
US
|
Family ID: |
36650200 |
Appl. No.: |
12/460101 |
Filed: |
July 14, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11096920 |
Mar 31, 2005 |
7589340 |
|
|
12460101 |
|
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Current U.S.
Class: |
324/658 |
Current CPC
Class: |
A61L 9/037 20130101;
A61L 9/127 20130101; G01F 23/265 20130101; G01F 23/2921 20130101;
A01M 1/2077 20130101; G01F 23/268 20130101 |
Class at
Publication: |
324/658 |
International
Class: |
G01R 27/26 20060101
G01R027/26 |
Claims
1. (canceled)
2. A system for detecting a container or contents of the container,
the system comprising: a diffuser for retaining the container, the
container configured to hold an active material therein and having
a wick extending therefrom; and a sensor positioned to detect at
least one of the container retained in the diffuser and the
contents of the container retained in the diffuser; wherein the
sensor is a capacitance-type sensor that detects a change in
capacitance of an area adjacent the sensor.
3-16. (canceled)
17. A system for detecting a container or contents of the
container, the system comprising: a diffuser for retaining the
container, the container configured to hold an active material
therein and having a wick extending therefrom; a capacitance
element disposed adjacent the wick; and a capacitance sensor for
sensing a change in capacitance of the capacitance element.
18. The system of claim 17, wherein the capacitance element
comprises two pieces of foil disposed adjacent the wick and
opposing one another and wherein the capacitance sensor and the
capacitance element are operatively connected to detect a change in
capacitance between the two pieces of foil.
19. The system of claim 18, wherein a wet wick increases
capacitance in the capacitance element, thereby indicating that the
container has active material therein and wherein a dry or missing
wick nominally increases capacitance in the capacitance element,
thereby indicating that the container is absent or empty.
20. The system of claim 17, wherein the capacitance element
comprises a tubular foil structure disposed around and adjacent the
wick and wherein the capacitance sensor and the capacitance element
are operatively connected to detect a change in capacitance in the
tubular foil structure.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable
REFERENCE REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable
SEQUENTIAL LISTING
[0003] Not applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention relates to detection systems, and more
particularly, to detection systems that can detect an absent or
empty container in a diffuser.
[0006] 2. Description of the Background of the Invention
[0007] A multitude of liquid active material emitting devices or
diffusers exist in the marketplace. Many of such devices are
passive devices that require only ambient air flow to disperse the
liquid active material therein. Other devices have a cord and plug
extending from the device, a plug extending directly from the
device, or batteries, to power elements of the device. In devices
having a heater, fan, or other active emitting unit, the user often
has no indication that a liquid active material container therein
is absent or empty, and therefore the device and its components
remain active.
[0008] Others have attempted to detect an almost empty condition in
a bag or bottle by measuring the capacitance of the contents in the
bag or bottle. One such device is attached to a bag or bottle and
detects a liquid level of the bag or bottle by detecting a change
in capacitance thereof. When the liquid level falls below a
specific liquid level, an alarm is generated to signal a user of
the condition. Another invention has a capacitance-type fluid level
sensor for I.V. and catheter bags. The sensor has conductive plates
disposed on an outer surface of a bag to detect a variation in the
capacitance of the fluid. When a variation is detected, a
comparator determines the level of the fluid. If the fluid is below
a threshold level, an alarm signal is provided to an alarm
driver.
[0009] Another device that detects liquid by measuring the
capacitance thereof is an apparatus for detection of liquid
incendiaries. The apparatus has a sling supported by first and
second supports, wherein two copper strips connected by a
conducting wire are attached to the sling. A bottle having contents
therein that function as a dielectric medium of a capacitor is
disposed in the sling between and in contact with the copper
strips. The capacitance of the apparatus changes based on the
contents of the bottle, wherein an output signal is generated to
indicate the capacitance. When the output signal reaches a
predetermined threshold voltage, a light emitting diode (LED) is
illuminated.
[0010] Other devices use light emitters and light detectors to
detect a fluid level in a container. One such device has a light
emitter, a light detector disposed adjacent one another near an
opening of a container, and a fluid level detector having a light
conduit portion, a base surrounding the light conduit portion, two
paddles moveably attached to opposite sides of the base, and a
biasing member extending between the paddles. Light is emitted
through the conduit in the opening and into the container. A
reflector disposed on the biasing member reflects the light back
through the conduit to the light detector. When the container is
full, the biasing member and paddles are biased outwardly. As the
container empties, the container begins to collapse, which causes
the biasing member and paddles to move inwardly toward one another.
Therefore, the reflector is moved away from the conduit, emitter,
and detector, thereby varying a path of the light, and thus the
intensity of the light received by the detector. The intensity of
the light received by the detector is used as an indicator of a
fluid amount in the container.
[0011] Another device for emitting and controlling the release of
volatile materials having an article containing volatile disposed
therein has a mechanism that communicates information from the
article to the device. The mechanisms have: electrical contacts on
or in the article that are capable of being read by electrical
circuitry in the device, conductive labeling on or in the article
that mates with contacts associated with the device, optical
mechanisms including bar coding on the article being read by the
device, changes in topography on the article that are capable of
being read by sensors in the device, or a radio frequency (RF)
identification tag on or in the article that communicates with the
device.
SUMMARY OF THE INVENTION
[0012] According to one aspect of the present invention, a system
for detecting a container or contents of the container comprises a
diffuser for retaining the container, wherein the container is
configured to hold an active material therein and includes a wick
extending therefrom. The system further includes a sensor
positioned to detect at least one of the container retained in the
diffuser and the contents of the container retained in the
diffuser.
[0013] According to another aspect of the present invention, a
system for detecting a container or contents of the container
comprising a diffuser for retaining the container, wherein the
container is configured to hold an active material therein. The
system further includes an emitter disposed adjacent the container
and a receiver disposed adjacent the container. The emitter and
receiver are operatively connected to detect at least one of the
container retained in the diffuser and the contents of the
container retained in the diffuser.
[0014] According to yet another aspect of the present invention, a
system for detecting a container or contents of the container
comprises a diffuser for retaining the container, wherein the
container is configured to hold an active material therein and
includes a wick extending therefrom. The system further includes an
emitter disposed adjacent the wick and a receiver disposed adjacent
the wick. The emitter and receiver are operatively connected to
detect at least one of the container retained in the diffuser and
the contents of the container retained in the diffuser.
[0015] According to still another aspect of the present invention,
a system for detecting a container or contents of the container
comprises a diffuser for retaining the container, wherein the
container is configured to hold an active material therein and
includes a wick extending therefrom. The system further includes a
capacitance element disposed adjacent the wick and a capacitance
sensor for sensing a change in capacitance of the capacitance
element.
[0016] Other aspects and advantages of the present invention will
become apparent upon consideration of the following detailed
description and the attached drawings, in which like elements are
assigned like reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 a perspective view of a diffuser;
[0018] FIG. 2 is a side view of the diffuser of FIG. 1;
[0019] FIG. 3 is a cross-sectional view of the diffuser of FIG. 2
incorporating a container having liquid active material and a
detection system therein and taken generally along the lines 3-3 of
FIG. 2;
[0020] FIG. 4 is a fragmentary cross-sectional view of a container
having liquid active material therein and an embodiment of a
detection system of FIG. 3 with portions behind the plane of the
cross-section omitted for purposes of clarity;
[0021] FIG. 5 is a plan view of the embodiment of FIG. 4;
[0022] FIG. 6 is a fragmentary cross-sectional view similar to that
of FIG. 4, wherein the container is replaced by an empty
container;
[0023] FIG. 7 is a plan view of the embodiment of FIG. 6;
[0024] FIG. 8 is a fragmentary cross-sectional view similar to that
of FIG. 4 having a container having liquid active material therein
and embodying a second embodiment of a detection system, with
portions behind the plane of the cross-section omitted for purposes
of clarity;
[0025] FIG. 9 is a plan view of the embodiment of FIG. 8;
[0026] FIG. 10 is a fragmentary cross-sectional view similar to
that of FIG. 8, wherein the container is replaced by an empty
container;
[0027] FIG. 11 is a plan view of the embodiment of FIG. 10;
[0028] FIG. 12 is a front view of another diffuser of the present
invention;
[0029] FIG. 13 is a side view of the diffuser of FIG. 12;
[0030] FIG. 14 is a cross-sectional view of the diffuser of FIG. 12
incorporating a container having liquid active material and a
detection system therein and taken generally along the lines 14-14
of FIG. 13;
[0031] FIG. 15 is a fragmentary cross-sectional view of a container
having liquid active material therein and a third embodiment of a
detection system, with portions behind the plane of the
cross-section omitted for purposes of clarity;
[0032] FIG. 16 is a fragmentary cross-sectional view similar to
that of FIG. 15, wherein the container is replaced by an empty
container;
[0033] FIG. 17 is a fragmentary cross-sectional view of a container
having liquid active material therein and a fourth embodiment of a
detection system, with portions behind the plane of the
cross-section omitted for purposes of clarity;
[0034] FIG. 18 is a fragmentary cross-sectional view similar to
that of FIG. 17, wherein the container is replaced by an empty
container;
[0035] FIG. 19 is a fragmentary cross-sectional view of a container
having liquid active material therein and a further embodiment of a
detection system, with portions behind the plane of the
cross-section omitted for purposes of clarity;
[0036] FIG. 20 is a fragmentary cross-sectional view similar to
that of FIG. 19, wherein the container is replaced by an empty
container.
[0037] FIG. 21 is a front view of another embodiment of a detection
system of the present invention;
[0038] FIG. 22 is a side view of the embodiment of FIG. 21;
[0039] FIG. 23 is a cross-sectional view of the embodiment of FIG.
21 taken generally along the lines 23-23 of FIG. 22, wherein
portions behind the plane of the cross-section have been omitted
for purposes of clarity; and
[0040] FIG. 24 is a cross-sectional view of a further embodiment,
wherein portions behind the plane of the cross-section have been
omitted for purposes of clarity.
[0041] FIG. 25 is a front view of a further embodiment of a
detection system of the present invention; and
[0042] FIG. 26 is a diagram of an exemplary circuit for controlling
one or more components of the present invention;
DETAILED DESCRIPTION OF THE INVENTION
[0043] FIGS. 1 and 2 illustrate a diffuser 52 generally comprising
a housing 54 having a compartment 56 configured to receive and
releasably hold a container 58 of active material having a wick 60
extending therefrom, and an electrical plug 62 for connecting the
diffuser 52 to a power source. In one embodiment of the present
invention, the active material is a liquid active material, but may
also be a solid, semi-solid, gel-like, or combinations thereof. The
diffuser also may have a heating element 64 to enhance the
diffusion of the active material in the container 58.
[0044] Illustratively, the housing 54 is made of a thermoplastic
material and is injection molded, although the housing 54 may be
made of any other suitable material. As seen in FIGS. 1 and 2, the
housing 54 includes an upper portion 66 and a lower portion 68 that
are fastened together by heat-staking or any other suitable
fastening means, including, for example, rivets, press fit, snap
fit, screws, ultrasonic welding, adhesives, or the like and
combinations thereof. The upper portion 66 substantially forms the
compartment 56 into which the container 58 is inserted. A front
surface 70 of the upper portion 66 of the housing has an opening 72
that engages a raised pattern 74 on the container 58 to releasably
hold the container 58 in place in the housing 54 during use. The
front surface 70 of the upper portion 66 of the housing 54 is
sufficiently pliant so that pulling the container 58 in a downward
direction causes the raised pattern 74 to release from the opening
72 in the front surface 70, thereby enabling removal of the
container 58 from the diffuser 52. Optionally, the diffuser 52 may
include an adjustment mechanism 75 for moving the wick 60 toward
and away from the heater 64, thereby increasing and decreasing,
respectively, the amount of liquid active material that is
volatilized. Alternatively, a neck portion 76 of the container 58
may be designed, for example, to snap to, or screw into, the
housing 54. Suitable containers are available in a wide variety of
liquid formulations from S.C. Johnson & Son, Inc., of Racine,
Wis., under the GLADES PLUGINS.RTM. SCENTED OIL.RTM. and RAID.RTM.
brand names.
[0045] In one embodiment of the present invention, the heating
element 64 is a metal oxide resistor potted in a ceramic block,
which is capable of handling up to at least about 5W. One suitable
resistor is a 6 k.OMEGA. resistor, capable of handling 5W.
Alternatively, the heating element 64 may comprise any other
suitable type of heating device, such as a resistance heater, a
wire-wound heater, a positive temperature coefficient (PTC) heater,
or the like, and combinations thereof.
[0046] The plug 62 may be disposed in either the upper or lower
portion 66, 68, of the housing 54, and/or may be configured as a
separate element that is interposed between the upper and lower
portions 66, 68 of the housing during assembly. Illustratively, the
plug 62 is secured to the housing 54 in a manner that allows the
plug 62 to rotate relative to the housing 54, in order to support
the diffuser 52 in an upright position in both horizontal and
vertical wall outlets.
[0047] Optionally, the diffuser 52 may include a wick adjustment
mechanism as described in, for example, U.S. Patent Application
Publication No. 2003/0138241 A1, which is hereby incorporated by
reference.
[0048] A wick of the present invention may be of any desired wick
material, such as, for example, a porous/sintered plastics or
polymers, such as ultra-density or ultra-high-density polyethylene
and polypropylene, bonded fibers, glass sintered fibers, ceramic
materials, carbon fibers, sintered carbon, wood, metal foams,
compressed wood composites, bundled fibers, woven material fibers,
natural fibers, synthetic fibers, and the like. Examples of natural
fibers useful in the present invention include cotton and linen.
Examples of synthetic fibers useful in the present invention
include nylon, polypropylene, polyethylene, polyesters, polyamides,
rayon, and polyacetates. Examples of wick materials useful in the
present invention are described in, for example, U.S. Patent
Publication No. 2002/0136886. One consideration in the selection of
the wick material used in a diffuser of the present invention is
the temperature required for the volatilization of the active
material selected and the temperature tolerance of the wick
material. For example, ceramic has a high temperature tolerance,
while natural fibers generally have a lower temperature tolerance.
The ability to tailor pore size to address wicking rates and
fouling is also a consideration when selecting the wick material.
Mixtures and combinations of the above wick materials may also be
used in the present invention. A container of the present invention
may also include one or more wicks of the same or different wick
material. Optionally, the wick of the present invention may be
surrounded by a plastic shield to protect components of the
diffuser from contact with the liquid active material contained in
the wick.
[0049] As seen in FIGS. 3-7, a first embodiment of the detection
system of the present invention as incorporated into the diffuser
52 of FIGS. 1 and 2 includes a light emitter 80 and a light
receiver 82 disposed on opposite sides of the wick 60 that extends
from the container 58. Illustratively, the light emitter 80 is an
LED, but may also be any other lighting element that produces
infrared, ultraviolet, red light, and/or visible light. Optionally,
the light emitter 80 may be a modulated light source and/or may be
a colored LED. An example of a suitable LED is a red LED modulated
at 10 kHz with a model number L7113SECH from Kingbright Corporation
of Taipei, Taiwan. Selection of the light emitter may depend on
many factors, including, but not limited to, the necessary luminous
intensity, the necessary viewing angle, the light emitter size, the
desired color, the desired wavelength, the distance or placement of
the light emitter within the diffuser, the electronics circuitry
and/or functionality used in the diffuser, and/or any other
relevant factors. In this embodiment, the light receiver 82 is a
phototransistor, but may also be any other light receiving element
that is sensitive to and/or can detect and/or receive infrared,
ultraviolet, red light, and/or visible light, including a
photodiode. An example of a suitable phototransistor is a
phototransistor sold under model number PT928-6C by Everlight
Electronics Co. Ltd. of Taipei, Taiwan.
[0050] The light emitter 80 and light receiver 82 may be attached
to any portion of the diffuser 52 that surrounds the wick 60 and
allows the light emitter 80 and light receiver 82 to be disposed
in-line with one another. As seen in FIG. 3, the light emitter 80
and light receiver 82 may be attached to first and second portions
83, 84 of a wick centering element 85 disposed in the diffuser 52.
The light emitter 80 and light receiver 82 may be attached by any
means known in the art. In an example, the light emitter 80 and
light receiver 82 (or other components of a detection system) may
be attached to a disk-shaped circuit board. The circuit board may
be disposed perpendicular to an axis of the wick 60 with the light
emitter 80 and light receiver 82 disposed adjacent the wick 60 (or
container 58 in the appropriate embodiments). The circuit board is
attached to the housing 54 by any means known in the art. For
example, the circuit board may be attached to the housing by
adhesive, a snap-fit connection, screws, an interference fit, or
the like.
[0051] Optionally, the light emitter 80 and light receiver 82 may
be disposed near a top portion of the wick 60. If a user inserts a
container 58 with a short wick 60, or if the user does not fully
insert the container 58 into the diffuser 52, the wick 60 may not
extend into the path between the light emitter 80 and light
receiver 82, and thus, the light transmitted by the emitter 80 is
detected directly by the receiver 82. In such scenario, the
diffuser 52 may treat this situation as if the container 58 were
absent and trigger an event to indicate such condition.
[0052] As seen in FIGS. 4 and 5, when the container 58 is full or
contains an amount of liquid active material therein, the wick 60
absorbs the liquid active material, thereby allowing the liquid
active material to spread throughout the entire wick 60. In such a
case, when the liquid active material remains in the container 58
and the wick 60 is wet, light from the light emitter 80 is
refracted through the saturated porous wick 60, allowing some light
to be detected by the receiver 82. The refractive index of the
liquid active material and the material of the wick determine the
amount of light from the light emitter 80 that is actually detected
by the light receiver 82. For example, in one embodiment, since
water has a very low refraction index, if the container 58 has
water therein and the wick 60 absorbs water throughout, the light
emitted from the light emitter 80 is not refracted through the wick
60 and is therefore not detected by the light receiver 82.
Therefore, in one embodiment of the present invention, the liquid
active material must have a high enough refractive index to refract
light through the wick 60 to ensure that light will be detected by
the receiver 82.
[0053] When the container 58 is empty, as seen in FIGS. 6 and 7,
the wick 60 does not have any liquid active material to absorb and
thus, the wick 60 becomes dry. Generally, a dry state occurs within
about seventy-two hours of the liquid active material completely
evaporating, but this varies depending on the material used for the
wick and the properties of the liquid active material. In this
embodiment, when the wick 60 is dry or empty, light from the light
emitter 80 enters the dry wick and is reflected into the many
cavities of the porous wick 60, with light being absorbed. At some
point, the light is no longer transmitted through the wick and
therefore does not reach the light receiver 82.
[0054] In the embodiment of FIGS. 4-7, if the container 58 and
therefore the wick 60 are absent and thus, not inserted into the
diffuser 52, light is emitted from the light emitter 80 and
received without interruption by the light receiver 82. In this
case, the light receiver 82 receives direct light from the light
emitter 80 and thus, the light received has a greater intensity
than the light received by the receiver 82 when the wick 60 is
wet.
[0055] As should be evident from the foregoing, in the embodiment
of FIGS. 4-7, three different conditions may be present and
detectable: an absent container 58, an empty container 58, and a
full or partially full container 58. In this embodiment, different
signals may be developed for each condition. For example, the
receipt of light by the light receiver 82, indicating a full or
partially full container 58, may signal the diffuser 52 to operate
in its normal fashion. Further, the non-receipt of light by the
light receiver 82, indicating an empty container 58, may trigger an
event in the diffuser 52 to indicate to the user that the container
58 is absent or empty. For example, non-receipt of light by the
light receiver 82 may trigger the device to deactivate the heater
64 (FIG. 2). Optionally or in addition, the diffuser 52 may include
an LED indicator on an outer surface thereof that may be activated
to indicate that the indicating an absent container 58, may trigger
a similar or different event by the diffuser 52.
[0056] Optionally, the light receiver 82 of FIGS. 4-7 may be a
different type of light receiving device, such as a light pipe.
When the container 58 contains liquid active material, the light
pipe 82 receives light transmitted by the light emitter 80 and
directs the light onto a surface that is visible to the user to
indicate that the diffuser is fully functioning. Alternatively,
when the container 58 is empty, no light is visible to the user,
thereby indicating that the device is not fully functional.
[0057] In the embodiments of FIGS. 3-7, the light receiver 82 is
disposed close to the wick 60 in order to reduce or minimize the
amount of stray light that the receiver 82 might detect and/or to
increase or maximize the light intensity to increase the likelihood
of the receiver 82 detecting the light from the emitter 80. In an
example, the light emitter 80 and the light receiver 82 are
potentially both disposed between about 1 mm and about 10 mm from
the wick 60, and more preferably between about 2.5 mm and about 7.5
mm from the wick 60, and most preferably about 5 mm from the wick
60. Optionally, the light emitter 80 and/or light receiver 82 may
be disposed greater than 10 mm from the wick 60. When the distance
between the light emitter 80 and/or light receiver 82 and the wick
60 is greater than 10 mm, a collimator or a light pipe may be
employed to focus the light emitted into the wick 60 and the light
coming from the wick 60. A collimator may also be used for
distances less than 10 mm in order to increase the efficiency of
the detection device. Examples of collimators include a narrow
tube, a straight or shaped lens, or any other known collimator.
[0058] Although in FIGS. 3-7 the light emitter 80 and light
receiver 82 are shown disposed adjacent the wick 60 above first and
second sides 90, 92 of the container 58, the light emitter 80 and
receiver 82 may also be disposed in the same manner adjacent the
wick 60 at or near the front and back 94, 96 of the container 58.
Alternatively, the light emitter 80 and light receiver 82 may be
disposed in any corresponding position surrounding the wick 60,
wherein the light emitter 80 and light receiver 82 are on opposite
sides of the wick 60.
[0059] As seen in FIGS. 8-11, a second embodiment of the detection
system of the present invention as incorporated into the diffuser
52 of FIGS. 1 and 2 includes a light emitter 180 and a light
receiver 182 disposed around a wick 160 that extends from a
container 158. In this embodiment, the light emitter 180 and light
receiver 182 are at an approximate right angle to one another, but
may also be at any other desirable or suitable angle wherein the
light receiver 182 can potentially detect light from the light
emitter 180. Also in this embodiment, the light emitter 180 is an
LED and the light receiver 182 is a phototransistor, but either may
also be any other device that emits or receives light as described
herein or known in the art. The LED of FIGS. 8-11 may be slightly
offset from a center of the wick 160 so as to avoid partial
illumination of the wick 160 in front of the light receiver 182.
The light receiver 82 is disposed close to the wick to reduce or
minimize receipt of stray light by the receiver 82.
[0060] When the container 158, as seen in FIGS. 8 and 9, is full or
contains an amount of liquid active material therein, the wick 160
absorbs the liquid active material, thereby allowing the liquid
active material to wick or move throughout the entire wick 160.
When the wick 160 is wet, light from the light emitter 180 is
refracted through cavities of the porous wick 160, thereby allowing
some of the light to be detected by the light receiver 182. As seen
in FIGS. 10 and 11 when the container 158 is empty, no liquid
active is absorbed by the wick 160 and thus, the wick 160 is dry.
When the wick 160 is dry, light from the light emitter 180 is
absorbed by the wick 160 and therefore does not reach the light
receiver 182. Also, when the container 158 and wick 160 are not
inserted into the diffuser 52, no light is detected by the receiver
182.
[0061] In the embodiment of FIGS. 8-11, the non-receipt of light by
the light receiver 182 indicating an absent or empty container 158
may trigger an event in the diffuser 52, as described herein, to
indicate to the user that the container 158 is absent or empty.
[0062] In an example of the embodiments of FIGS. 8-11, the light
emitter 180 and the light receiver 182 are potentially both
disposed between about 1 mm and about 10 mm from the container 158,
and more preferably between about 2.5 mm and about 7.5 mm from the
container 158, and most preferably about 5 mm from the container
158. Optionally, the light emitter 180 and/or light receiver 182
may be disposed greater than 10 mm from the container 158. As in
the embodiment of FIGS. 4-7, when the distance between the light
emitter 180 and/or light receiver 182 and the container 158 is
greater than 10 mm, a collimator or a light pipe may be employed to
focus the light emitted into the container 158 and the light coming
from the container 158. A collimator may also be used for distances
less than 10 mm, in order to increase the efficiency of the
detection device. Examples of collimators include a narrow tube, a
straight or shaped lens, or any other known collimator.
[0063] As with the first embodiment, the light emitter 180 and
light receiver 182 of FIGS. 8-11 may be operatively positioned
and/or connected in any manner that is suitable for the respective
diffuser. For example, the light emitter 180 and light receiver 182
may be disposed at any angle with respect to one another and/or
they may both be disposed at any position with respect to the wick
160 and the container 158.
[0064] The light emitter 80, 180 and light receiver 82, 182 of
FIGS. 3-11 may be disposed near a top portion of the wick 60, 160,
such that, if a container 58 having a shorter wick 60, 160 is
inserted into the diffuser 52, or if the container 58 is not fully
inserted into the diffuser 52, the light emitter 80, 180 and light
receiver 82, 182 will not detect the wick 60, 160. In such a
situation, the receipt or non-receipt of light by the light
receiver 82, 182 may trigger an event in the diffuser 52 similar to
that which would indicate an absent container 58, 158.
[0065] FIGS. 12-14 illustrate a diffuser 252 similar or identical
to the other diffuser embodiments disclosed herein and generally
comprising a housing 254 having a compartment 256 configured to
receive and releasably hold a container 258 of liquid active
material having a wick 260 extending therefrom, and an electrical
cord and plug 263 for connecting the diffuser 252 to a power
source. Still further, the diffuser may also include at least one
LED (not shown) for illuminating the surrounding area and at least
one lens 300 in a front portion 302 thereof for allowing light from
the at least one LED to escape therefrom. The diffuser 252 also may
have a heating element 264 as described in detail above, to enhance
the diffusion of the active material from the container 258 and one
or more vent holes 304 disposed in a top portion 306 and/or a rear
portion 308 thereof for dispersion of active material from the
diffuser 252.
[0066] FIGS. 15 and 16 depict a third embodiment of the detection
system of the present invention as incorporated into the diffuser
252 of FIGS. 12-14, although the detection system may be
incorporated into any diffuser. The detection system includes a
light emitter 280 and a light receiver 282 disposed substantially
in line with one another around the container 258 and in light
communication with one another through the liquid active material
in the container 258. The light emitter 280 is an LED and the light
receiver 282 is a phototransistor, but as with other embodiments,
any light emitter(s) and/or light receiver(s) known in the art may
be employed. If one of the light emitter 280 and the light receiver
282 is positioned above a fill-level 310 of a full container 258
and the other of the emitter 280 or receiver 282 is located at a
bottom 311 of the container 258, as seen in FIGS. 15 and 16, an
empty state (FIG. 16) of the container 258 may be detected. In this
case, the light receiver 282 receives light transmitted from the
light emitter 280 when the container 258 is absent or empty.
Otherwise, when the light enters the container 258 and reaches a
top 312 of the liquid active material, the light is reflected
and/or refracted, and thus, does not reach the receiver 282. In
either case, the receipt or non-receipt of light by the receiver
282 is indicated to the user with some form of notice that the
container 258 is absent or empty.
[0067] A fourth embodiment of the detection system of the present
invention as incorporated into the diffuser 252 of FIGS. 12-14 and
as seen in FIGS. 17 and 18, includes a light emitter 280 and a
light receiver 282 disposed around the container 258, but not
in-line with one another. When the light transmitted by the light
emitter 280 enters a container 258 with an amount of liquid active
material therein (FIG. 17), the liquid active material causes the
light to bounce around within the liquid active material between a
top fluid-air interface 314 and a container 258 bottom interface
316, whereby a portion of the light is detected by the light
receiver 282 as it exits the bottom interface 316. Conversely, when
the light transmitted by the light emitter 280 enters a container
258 with no liquid active material therein (FIG. 18), the light is
transmitted through and out the opposite side of the container 258,
thereby never reaching the receiver 282. Similarly, when no
container 258 is present, light transmitted by the light emitter
280 is directed in a straight line and never reaches the receiver
282. As with the previous embodiments, the receipt or non-receipt
of light by the receiver 282 may trigger an event by the diffuser
252, whereby the condition is indicated to the user.
[0068] Yet another embodiment of the detection system of the
present invention, similar to those of FIGS. 15-18, as incorporated
into any diffuser as described herein or known in the art is
depicted in FIGS. 19 and 20. The system includes a light emitter
280 and a light receiver 282 disposed above the container 258 and
not in-line with one another. When light is transmitted by the
light emitter 280 and enters the container 258 that includes liquid
active material therein (FIG. 19), the liquid active material
causes the light to bounce around within the liquid active material
between a top fluid-air interface 314 and a container 258 bottom
interface 316, wherein a portion of the light is detected by the
light receiver 282 as it exits the top interface 314. When light is
transmitted through the container 258 with no liquid active
material therein (FIG. 20), the light does not reach the receiver
282, as discussed above in relation to the embodiment of FIGS. 17
and 18. Again, the receipt or non-receipt of light by the receiver
282 may trigger an event by the diffuser 252 to indicate to a user
that a container 258 is absent or empty.
[0069] The location of the receiver in the embodiments of FIGS.
15-18 largely determines how and/or when an empty condition is
detected and/or triggered by the diffuser. For example, if the
receiver is adjacent a bottom portion of the container, the
diffuser will generally detect and/or trigger an empty condition
when there is no liquid active material left therein. Conversely,
if the receiver is spaced between the bottom portion of the
container and the top portion of the container, the diffuser will
generally detect and/or trigger an empty condition when some small
amount of liquid active material remains therein. This can be
useful in detecting when the container is almost empty rather than
detecting when the container is fully empty. In other embodiments,
multiple receivers can be disposed at various locations to indicate
various liquid levels and/or an empty container.
[0070] In the embodiments of FIGS. 15-18, the container is clear
(translucent) or opaque so that light transmitted by the light
emitter is allowed to pass through the container and be detected by
the light receiver. Optionally, the container may be any other
color if it is desirous to, for example, only detect whether the
container is absent.
[0071] Although the embodiments of FIGS. 15-20 depict the light
emitter 280 and light receiver 282 adjacent the container 258 near
a first side 290 and a second side 292 of the container 258, the
light emitter 280 and the light receiver 282 may also be disposed
in the same manner adjacent a front side (not shown) and a back
side (not shown) of the container 258. Alternatively, the light
emitter 280 and light receiver 282 may be disposed in any relative
positions surrounding the container 258, wherein the light emitter
280 and light receiver 282 are either in-line with one another or
out of line with one another.
[0072] The light emitter of the embodiments of FIGS. 15-20 is
driven using about a 8.5 kHz square wave. The drive frequency of
the light emitter is not critical and, in fact, the light emitter
may receive direct current (meaning full on). The light receiver
may be coupled to any suitable detection circuit, such as an AM,
FM, phase shift, or direct level measurement circuit. It should be
noted that some detection schemes are more robust than others and
are less adversely affected by ambient light.
[0073] In another embodiment similar to those of FIGS. 15-20, the
light emitter and light receiver may be placed on the same surface
of the container. In such an embodiment, emitted light travels into
liquid active material in the container and bounces off a reflector
placed on a surface of the container or adjacent the container. A
portion of the light travels through the liquid active material and
is received and detected by the light receiver. Optionally, the
reflector may be placed on the wick or inside the container.
[0074] As seen in FIGS. 21-23, another embodiment of the detection
system of the present invention as incorporated into the diffuser
52 of FIGS. 1 and 2, the diffuser 252 of FIGS. 12 and 13, or any
other known diffuser, employs an electric field sensor to detect an
absent or empty container 458. Illustratively, as seen in FIGS.
21-23, a tubular foil structure 520 is disposed around and
surrounds the wick 460 that extends from the container 458. The
foil structure 520 is coupled to a suitable excitation and
detection circuit. An indication can be generated when a wick is
absent, or when a wick is present, but is dry, or when a wet wick
is present.
[0075] In yet another embodiment of a detection system, one or more
metal plates or foils may be disposed adjacent or around the wick.
In such embodiment, the plate(s) detects the presence of an induced
electrical field. The metal plate may be any kind of metal that is
conductive including, but not limited to, copper, gold, aluminum,
silver, or any other conductive metals. Optionally, any other
conductive material may be utilized. In this embodiment, any object
that is conductive and has a different dielectric constant than its
surroundings may be sensed by its effect on the electrical field.
Using multiple electrodes, the size and shape of the object can be
determined. The electrical field is suitable for detecting objects
that are either fixed or in motion within the electrical field.
[0076] Optionally, as seen in FIG. 24, a capacitance sensor may
comprise two straight or curved foil structures 520a, 520b disposed
adjacent the wick 460 opposing one another. A capacitance between
the foil structures 520a, 520b is continuously measured and
differences in the capacitance between the foil structures 520a,
520b are detected. In one embodiment, the capacitance is measured
by an oscilloscope probe, but may instead be measured by any other
device that measures capacitance and is sized to fit in the
respective diffuser. When a dry wick 460 is present adjacent the
foil structures 520a, 520b, the capacitance of the foil structures
520a, 520b increases by about five percent from the nominal
capacitance of the foil structures 520a, 520b with no wick 460
present. When a wet wick 460 is present adjacent the foil
structures 520a, 520b, the capacitance between the foil structures
520a, 520b increases by about twenty percent from the nominal
capacitance between the foil structures 520a, 520b. Due to the
different capacitance values between the foil structures 520a, 520b
with no wick 460, a dry wick 460, and a wet wick 460, different
events can be detected and/or triggered by the diffuser 52, 252 for
each condition.
[0077] Another device that may be utilized to measure the
capacitance of a capacitance sensor employs an inductor coupled in
parallel with the capacitance sensor to form a tank circuit. In
such a circuit, any change in capacitance directly changes the
resonant frequency of the circuit. The circuit may be calibrated to
detect the difference in frequency between an empty container, an
absent container, a container having a wick that is fully saturated
with liquid active material, and/or any other suitable conditions.
An initial tuning of the circuit to resonance increases the maximum
sensitivity to allow for detection of small changes in
capacitance.
[0078] In the examples of FIG. 24, the foil structures 520a, 520b
of the capacitance sensor may be disposed between about 0.5 mm and
about 1.5 mm from the wick, and more preferably between about 0.75
mm and about 1.25 mm from the wick, and most preferably about 1.0
mm from the wick.
[0079] In a specific example of a capacitance sensor, two sections
of foil about 0.900 inch (2.286 cm) in length are disposed opposite
one another around the wick with about 0.060 inch (0.152 cm)
between the foil sections. One of the foil sections is excited by a
10 volt (peak-to-peak) 16 kHz sine wave and the other foil section
is connected to an oscilloscope probe. The nominal capacitance
between the foils is about 0.9 pF. A wet wick increases the
capacitance to between about 1.1 pF and about 1.4 pF depending on
the container and wick geometry. The output voltage is nominally at
about 412 mV (zero-to-peak) sine wave, but changes to between about
500 mV and about 635 mV depending on the properties of the wick and
the liquid active material.
[0080] In a further embodiment of a detection system, as seen in
FIG. 25 an electrical coil 621 acting as an inductor may be
disposed in a diffuser, such that when a container 658 with wick
660 is inserted into the diffuser, the electrical coil 621
surrounds the wick 660 without contacting the wick 660. This
arrangement creates a transformer of sorts, wherein any change in
the liquid absorbed by the wick 660 may change the tuned frequency,
thereby allowing for differentiation between a container 658 with
liquid active material therein and a container 658 with no active
liquid material therein.
[0081] Referring now to FIG. 26, a circuit 1000 for operating any
of the embodiments of FIGS. 4-11 and 15-20 is illustrated including
a light emitting diode LED1 and an optical transistor REC1
surrounding a wick or a container. The circuit 1000 includes an
oscillator section 1002, an LED driver section 1004, a receiver
section 1006, and a driver and filter section 1008.
[0082] The oscillator section 1002 includes a first op-amp 1010
having an inverting input coupled through a capacitor C1 to ground
potential. A resistor R1 is coupled between an output of the op-amp
1010 and the inverting input thereof. A further resistor R2 is
coupled between the output of the op-amp 1010 and a non-inverting
input thereof. The non-inverting input of the op-amp 1010 is
further coupled to a junction between biasing resistors R3 and R4
that are, in turn, coupled between a voltage VcC and ground
potential. In addition to the foregoing, a resistor R5 is coupled
between the output of the op-amp 1010 and the voltage V.sub.cc.
[0083] The driver section 1004 includes a transistor in the form of
a MOSFET Q1 having source and drain electrodes coupled to a cathode
electrode of LED1 and ground potential, respectively. A current
limiting resistor R6 is coupled between the voltage V.sub.cc and an
anode terminal of LED1.
[0084] The receiver circuit section 1006 includes a resistor R7
coupled between the voltage V.sub.cc and a collector electrode of
the optical transistor REC1. A drain electrode of the optical
transistor REC1 is coupled to ground potential. A capacitor C2 is
coupled between the collector electrode of the optical transistor
REC1 and an inverting input of a further op-amp 1012. The inverting
input of the op-amp 1012 is further coupled to a voltage divider
comprising resistors R8 and R9 that are coupled between the voltage
V.sub.cc and ground potential. A non-inverting input of the op-amp
1012 is coupled through a potentiometer RIO in series with further
resistors R11 and R12 across the voltage V.sub.cc and ground
potential.
[0085] The driver and filter section 1008 includes a resistor R13
coupled between an output of the op-amp 1012 and a junction between
a resistor R14 and a capacitor C3. The resistor R14 and capacitor
C3 are coupled across the voltage V.sub.cc and ground.
[0086] In any of the embodiments disclosed herein, the signal
developed at the junction between the resistor R14 and the
capacitor C3 may be provided to any suitable indicating device. In
the illustrated embodiment, such signal is provided to a gate
electrode of a first MOSFET transistor Q2. A drain electrode of the
transistor Q2 is coupled to ground potential and a source electrode
thereof is coupled to a series combination of a resistor R15 and a
light emitting diode LED2. The source electrode of the transistor
Q2 is coupled to a gate electrode of the further MOSFET transistor
Q3 having a drain electrode coupled to ground potential. A source
electrode of the transistor Q3 is coupled through a resistor R16 to
a further light emitting diode LED3. Common connected anode
electrodes of the LED2 and LED3 are coupled to the voltage
V.sub.cc.
[0087] In operation, the oscillator section 1002 produces a square
wave at a particular frequency of, for example, 8.5 kHz. This
square wave is applied to the gate electrode of the transistor Q1
causing the transistor Q1 to turn on and off at such frequency. The
LED1 is thereby energized at a rapid rate with the current
therethrough being limited by the resistor R6. When the light
produced by the LED1, which may be visible light or infrared light
is detected by the optical transistor REC1, the optical transistor
REC1 turns on and off at the oscillator frequency, thereby
producing an AC waveform at the junction between the resistor R7
and the capacitor C2. The capacitor C2 removes any DC component
that may be present in such signal and passes the resulting signal
to the inverting input of the op-amp 1012. The op-amp 1012 compares
the signal at the inverting input with the DC voltage at the
non-inverting input thereof as established by the setting of the
potentiometer RIO and the values of the resistances R11 and R12.
The result of the comparison is then applied through the RC filter
including the resistor R13 and the capacitor C3, which causes a
high state signal to be applied to the gate of the transistor Q2.
This condition, in turn, causes the transistor Q2 to conduct,
thereby causing current to flow through the LED2 and the resistor
R15 through the source and drain of the transistor Q2 to ground
potential. In addition, the voltage at the source electrode of the
transistor Q2 drops to a very low potential (substantially zero
volts), in turn causing the transistor Q3 to turn off and
preventing current flow through the LED3. Thus, when the light
emitted by the LED1 is received by the optical transistor REC1, the
LED2 is on and the LED3 is off.
[0088] Conversely, when the light developed by LED1 does not reach
the optical transistor REC1, no AC signal is produced at the
junction between the resistor R7 and the capacitor C2. As a result,
the output of the op-amp 1012 is in a low state, thereby turning
off the transistor Q2 and allowing the voltage at the gate of the
transistor Q3 to rise to a high level. Because the transistor Q3 is
a high impedance device, substantially no current flows through the
LED2 at this time, and hence LED2 is turned off. Current does flow,
however, between the source and drain of the transistor Q3, thereby
illuminating LED3.
[0089] As should be evident from the foregoing, the circuit shown
in FIG. 26 provides a positive indication when light developed by
LED1 reaches or does not reach the optical transistor REC1. Thus,
in those embodiments of the present invention where reception of
light developed by LED1 by the optical transistor REC1 indicates
that a wet wick is present, the LED2 is illuminated and the LED3 is
off. In such embodiments, when the wick is dry and therefore opaque
no light is received by the optical transistor REC1 and hence the
LED3 is illuminated and LED2 is off.
[0090] In those embodiments where, under the condition that the
refill is absent and no light from the LED1 is detected by the
optical transistor REC1, the LED3 is illuminated and LED2 is off.
In those other embodiments where light developed by LED1 is
received by the optical transistor REC1 when the refill is absent,
the LED2 is on and LED3 is off.
[0091] If desired, the oscillator section 1002 may be replaced by
any other suitable apparatus, such as an application-specific
integrated circuit (ASIC) or a micro controller or microprocessor.
In addition, any of the remaining components of the circuitry of
FIG. 26 may be replaced by other suitable circuitry, as desired.
For example, the transistors Q2 and Q3, the resistors R15 and R16,
and light-emitting diodes LED2 and LED3 may be replaced by a single
transistor or multiple transistors that are properly biased to
provide a signal to control apparatus that in turn controls any of
the components of the diffuser or a signaling apparatus of any
suitable type, such as one or more lights, an audible alarm, a
combination of lights and audible alarm or the like.
[0092] In any of the embodiments incorporating a light emitter
and/or a light receiver, a pulsed signal may be transmitted from
the light emitter to the light receiver, wherein the signal is an
amplitude modulated (AM) signal, a frequency modulated (FM) signal,
or a phase shifted signal. A suitable detector is coupled to the
receiving device to detect a refill condition.
[0093] A collimator may be utilized in any of the embodiments
herein that employ a light emitter and/or a light receiver. The
collimator in conjunction with a light emitter aids in focusing of
the light emitted from the light emitter. When used with a light
receiver, the collimator may reduce the effect of ambient light or
light coming from other angles or sources, thereby reducing the
amount of stray light received by the light receiver.
[0094] Any of the embodiments as disclosed herein may include a
system for zeroing or negating noise factors, such as temperature,
humidity, shock, vibration, customer use, active material spillage
onto the sensors, or any other noise factors. The system calibrates
the electronics whenever certain conditions exist, for example,
when the container is removed from the diffuser. In such example,
when the container is removed, the electronics will self-calibrate
to zero, thus creating a new baseline so that the diffuser can
differentiate between a container with liquid active material
therein, an empty container, and a missing container, among the
noise factors. An example of a system for activating the software
routine would be a mechanical arm that is in contact with the wick.
When the container is removed, the arm moves, thereby changing the
state of an electrical or optical switch. In another example of a
system for zeroing noise factors, an LED is disposed across from
the light emitter (in the applicable embodiments) to solely
determine the presence of the wick.
[0095] In any of the embodiments herein, the detection system may
be able to detect whether a foreign object, a container with no
wick, and/or a container with a wick having different container or
wick dimensions (e.g., height, width, thickness, etc.) is inserted
into the diffuser. For example, in a diffuser incorporating a
capacitance sensor, the capacitance of the sensor with a shorter
wick may produce an undetectable or insignificant change in
capacitance of the sensor, therefore indicating that a proper
container is not positioned therein. In another example involving a
diffuser incorporating a light emitter and light receiver
positioned around a wick, the light emitter and light receiver may
be positioned such that shorter wicks may not even interrupt light
between the light emitter and light receiver.
[0096] In order to preserve light emitters and/or light receivers
from damage or degradation from the liquid active material and/or
other substances, transparent plastic barriers may be disposed
between the wick and the light emitter and/or light receiver.
Alternatively, the plastic barrier may be disposed around the light
emitter and/or light receiver. The plastic barrier(s) may employ
any plastic material that has a high immunity to chemicals, yet
still allow transmission of light therethrough.
[0097] Illustratively, the liquid active material described herein
may be, for example, an insecticide, an insect repellant, an insect
attractant, a disinfectant, a mold or mildew inhibitor, a
fragrance, a disinfectant, an air purifier, an aromatherapy scent,
an antiseptic, an odor eliminator, an air-freshener, a deodorizer,
or the like, and combinations thereof, and may be in a liquid, gel,
semi-solid and/or solid form.
[0098] In one embodiment of the present invention, the diffusers
incorporating any embodiment of the detection system of the present
invention may include a printed circuit board that may include one
or more controllers, memories, and/or processors for controlling
the operation of the light emitter, the light receiver and/or the
capacitance sensor. The one or more controllers, memories, and/or
processors may also control alone or more of the elements of the
diffuser (for example, a heater, a light, a timer, etc.) and detect
an absent or empty container and trigger the respective event in
the diffuser to indicate to the user that the container is absent
or empty.
[0099] The construction of the diffusers and housings, as described
herein, is not critical. In fact, the light emitters, light
receivers, and/or sensors of the embodiments as described herein
may advantageously be incorporated into the housing of virtually
any device that uses a refill or replaceable container, including
for example, a diffuser for dispensing fragrance and/or
insecticide. Such a device can be found in for example, U.S. Pat.
No. 5,647,053. Other devices useful in the present invention
include those disclosed in, for example, U.S. Pat. No. 6,706,988.
Still other devices useful in the present invention include those
disclosed in, for example, U.S. Pat. No. 6,852,403. Further, other
devices useful in the present invention include those disclosed in,
for example, U.S. Reissue No. 38,150. The devices disclosed in, for
example, WO 2004/071935 may also be useful in the present
invention, Still other devices useful in the present invention
include those found in, for example, U.S. Pat. No. 6,697,571. Other
devices useful in the present invention include those disclosed in,
for example, U.S. Pat. No. 6,768,865. Further, the device disclosed
in, for example, U.S. Pat. No. 6,790,408 may be useful in the
present invention. Other devices useful in the present invention
include those found in, for example, U.S. Pat. No. 6,854,717. Still
further, devices useful in the present invention include those
found in, for example, U.S. Pat. No. 6,859,615, This listing of
exemplary devices is not meant to be exhaustive.
[0100] In any of the embodiments employing a light emitter, in
order to conserve power and the light emitter lifetime, the light
emitter can be pulsed discontinuously. For example, the light
emitter (and the light receiver) might be turned on about every 2
seconds, 5 seconds, 10 seconds, 30 seconds, 1 minute, 5 minutes, 10
minutes, or any other desired or suitable time period. In such
case, a timer may be connected to the light emitter and/or light
receiver to allow the diffuser to ascertain whether a wick is
absent or empty on a discontinuous basis. Pulsing the light emitter
discontinuously also reduces the temperature in the light emitter
and increases the resistance of the light emitter to the active
material. In order to further increase the resistance of the light
emitter and also the resistance of the light receiver to the active
material, one or both of the light emitter and light receiver may
be encased by a translucent housing.
[0101] In any of the embodiments described herein, the user may be
notified that there is an absent and/or empty container. Such
notice might include, for example, deactivating one or more
functions of the device, allowing only a single color light to be
emitted from the device, deactivating or activating a fan and/or a
heater, deactivating or activating a light(s), deactivating or
activating a sound or music, deactivating or activating a diffuser
element such as a pump, a piezoelectric element, etc., turning the
entire diffuser on or off, deactivating or activating a timer,
activating a blinking light, activating an alarm, or any other
means for notifying the user that a specific condition is
present.
[0102] Any of the embodiments disclosed herein may include a
secondary sensor that is part of the diffuser that may detect a
feature on the container. The secondary sensor may be operated at a
different frequency, time, and/or wavelength than the primary
sensor so as to not interfere therewith. For example, the secondary
sensor may be a light emitter, for example an LED, and the feature
on the container may be a structure that obstructs or focuses the
emitted light from light emitter. If the feature is present on the
container, the secondary sensor will detect such feature and
trigger an event in the device, such as turning on the diffuser, as
described in detail herein. Conversely, if the feature is not
present on the container, the secondary sensor will detect that the
feature is missing and trigger an event in the device, such as
turning off the diffuser, as described in detail herein.
[0103] In any of the embodiments as disclosed herein, the light
emitter(s), light receiver(s), and/or capacitance sensor(s) may be
configured to detect the actual level of the liquid active
material. For example, as the container reaches an empty state, the
light emitted or capacitance level may decrease, such that this
decrease is detectable. This would be useful in detecting a low
level of liquid active material in order to convey to the user that
the active material is near an empty state.
[0104] With any of the embodiments described herein, any number of
light emitters, light receivers, and/or capacitance sensors may be
employed to detect any absent or empty container.
INDUSTRIAL APPLICABILITY
[0105] The present invention provides systems for detecting an
absent or empty container within a diffuser. The systems of the
present invention may have particular applicability to diffusers
that emit fragrances or odor eliminating active materials, as well
as insecticide repelling or attracting materials active material.
In particular, the systems disclosed herein provided an indication
to the user of a diffuser device that a container is absent or
empty. Another benefit of the systems of the present invention is
that, when there is an absent or empty container, various elements
of the diffuser may be deactivated in order to conserve power,
battery life, LED life, etc.
[0106] Numerous modifications will be apparent to those skilled in
the art in view of the foregoing description. Accordingly, this
description is to be construed as illustrative only and is
presented for the purpose of enabling those skilled in the art to
make and use the invention and to teach the best mode of carrying
out same. All patents and other references cited herein are
incorporated by reference in their entirety. The exclusive rights
to all modifications which come within the scope of the appended
claims are reserved.
* * * * *