Scenting nebulizer with remote management and capacitive liquid level sensing

A scenting nebulizer is described that capacitively measures the level of scenting oil in a bottle in the nebulizer without ever contacting the oil in the bottle. In addition, such capacitively measured oil levels are measured at multiple vertical levels of the bottle of scenting oil. In actual operation the capacitively measured oil level readings are very frequently measured then averaged, and the averaged figures are stored. The stored, averaged figures are interpolated against previously stored, capacitance readings made when the scenting oil bottle is full and when there is no bottle. In this manner the level of the oil is accurately determined. A plurality of processor controlled scenting nebulizers are connected to a central computer and their individual oil levels and other operational information are forwarded to the central computer where appropriate maintenance for the individual nebulizers is scheduled. The operational settings operation of the nebulizers may be programmed from the central computer.

FIELD OF THE INVENTION

The invention relates to electronic liquid level sensors and, particularly, to a capacitive liquid level sensor that is functioning with a local microprocessor both used in a scenting nebulizer to monitor the level of scenting oil in a container inside the nebulizer in a way that does not physically contact the oil. The invention also relates to a centralized computer that monitors the operation of and the level of scenting oil in each of a plurality of remote scenting nebulizers and provides a warning signal when a problem is detected and/or the capacitive liquid level sensors of the nebulizers detect that the level of scenting oil in the nebulizer is low. The centralized computer also monitors the operating settings of the nebulizers and is used to program their operational settings.

More specifically, the capacitive liquid level sensor of the invention is utilized in a scenting nebulizer used in a public environment where “scenting” is used to attract consumers into a retail location or to promote the sale of specific products. The scenting can also be used in a professional environment in waiting rooms to calm patients or to neutralize odors.

BACKGROUND OF THE INVENTION

Currently most public and professional establishments that utilize a scenting nebulizer have no remote management of the nebulizer operational settings or an easy way to check scenting oil levels in the nebulizer. In addition, most of these scenting nebulizers are mounted in hard to reach places, for example, near or inside an HVAC system or high on shelves or in ceilings. Scenting oil levels can get low and run out which causes a support issue where the end-user believes the system is broken; and an intended use issue where the scenting nebulizer is not scenting creating a negative revenue generating environment.

Locations that utilize multiple scenting nebulizers that want to maintain consistency in the times the scenting nebulizers are turned on or off, or to verify all units are functioning correctly or at pre-programmed levels is not achievable with current scenting nebulizers presently available on the market with one exception. U.S. Pat. No. 5,563,811 teaches a system controller interfacing with a number of remote nebulizing humidifiers that allows operator control of the humidifiers via a human interface comprising a keypad and a liquid crystal display. The system controller, operating under control of a program, monitors the operational status of each humidifier and alarms the user on a humidifier fault. The system controller also receives a humidity control signal which monitors the humidity in a particular location or zone using humidity sensors. The system controller sends signals to individual nebulizing humidifiers to control their operation and correct the humidity levels.

What is needed in the art is means to periodically measure the level or amount of scenting oil in each scenting nebulizer, without physically contacting the scenting oil therein, and automatically report the level of oil back to a central location so that oil may replenished before it runs out.

What is also needed in the art is a scenting nebulizer, a number of which may be combined into a networked system, even with nebulizers being in locations remote from each other, and all the nebulizers are under the control of a central processor which monitors their operation for improved maintenance services. This includes monitoring the level of scenting oil in each remote nebulizer and causing the oil in a nebulizer to be replenished when the oil level is low.

SUMMARY OF THE INVENTION

The previously described needs in the prior art are satisfied by the present invention. In a preferred embodiment of the invention described herein a scenting nebulizer is provided which has a microprocessor controlled scenting oil pump and a scenting oil level detection means that does not physically contact the oil in the nebulizer. This aspect of the invention may be used to monitor liquid levels other than in a nebulizer. This no contact scenting oil level monitoring eliminates fouling of such oil level measuring means in the scenting nebulizers and thereby minimizes maintenance services. The scenting nebulizer has keys for inputting commands to the microprocessor to control the operation of the nebulizer and a display for providing visual indications of the operational characteristics of the nebulizer.

More specifically, the no contact oil level detection means is a capacitive oil level measuring means which functions with the microprocessor for periodically monitoring the level of the scenting oil in the nebulizer. The monitoring period can be as little as every few seconds. The scenting nebulizer is supplied scented oil via a replaceable bottle that is attached to the nebulizer. The oil bottle is screwed onto the nebulizing assembly through a front door of the scenting unit which has a clear door for visual check of the oil level.

In addition, a programmed central computer is provided that monitors and controls the operation of each of a plurality of networked scenting nebulizers, that may remotely located from each other, by communicating with the local microprocessors in each of the individual nebulizers. The central computer provides a warning signal when either a problem with a nebulizer is detected and reported by a local microprocessor to the central computer, and/or the capacitive liquid level sensor in the nebulizer detects that the level of scenting oil in the nebulizer is low and that condition is reported by the local microprocessor to the central computer. The central computer may also be used to program the operational settings of individual scenting nebulizers in the network of nebulizers. This eliminates the need to manually check the amount of scenting oil in each of the networked scenting nebulizers, which task is cumbersome when there are a large number of nebulizers and they are spread out and in relatively hard to reach places.

This centralized and networked operation assures that service providers of a scenting nebulizer service have the ability to control and manage a plurality of scenting nebulizers at a number of physical locations each having one or more scenting nebulizers. By continuously monitoring both the operational status and the scenting oil level of a number of remote scenting nebulizers the service provider can promptly maintain the nebulizers and can establish scenting oil reorder points and properly schedule maintenance that reduces or eliminates out-of-oil conditions.

This centralized and networked operation assures that service providers of a scenting nebulizer service have the ability to control and manage a plurality of scenting nebulizers at a number of physical locations each having one or more scenting nebulizers. By continuously monitoring both the operational status and the scenting oil level of a number of remote scenting nebulizers the service provider can promptly maintain the nebulizers and can establish scenting oil reorder points and properly schedule maintenance that reduces or eliminates out-of-oil conditions.

Communication between the local microprocessor of each of the scenting nebulizers at the same and/or different geographical locations and the central computer is accomplished by using a combination of wired and/or wireless local area networks and/or the Internet for transmitting control signals and monitoring information between the local microprocessor of each nebulizer and the central computer.

Each scenting nebulizer utilizes a novel capacitive oil level sensor that, in conjunction with its local processor, continuously monitors the level of scenting oil in the bottle of oil attached to each nebulizer without physically contacting the scenting oil. This contactless operation prevents any fouling of the oil level sensor over time and thereby minimizes maintenance of the sensor. The level of scenting oil measured by the capacitive oil level sensor in conjunction with the local microprocessor are forwarded by the local microprocessor to the central computer which monitors the scenting oil levels and the operational status of each of the plurality of scenting nebulizers for maintenance purposes. These maintenance purposes include but are not limited to, repairing malfunctions of a scenting nebulizer and replacing the scenting oil in each nebulizer. In the event that a scenting nebulizer is being operated in a standalone mode its microprocessor

Local programming of each scenting nebulizer, is performed right at the nebulizer, through a local interface in the form of an integrated LCD display and membrane keypad located on the front of each scenting nebulizer. The display and keypad are used to receive and send information from/to the local microprocessor associated with each scenting nebulizer. This local interface allows for scenting schedules to be manually programmed and activated based upon date and time. Additionally, nebulizer specific on and off scenting intervals, other network settings, and current time and date may also programmed through this local interface without the involvement of the central computer.

As previously mentioned, the monitoring and programming of individual scenting nebulizers located in different physical locations may be accomplished using a remote central computer with signals being transmitted back and forth between the central computer and the networked scenting nebulizers via a wired and/or wireless local area network and/or the Internet. This remote operation permits scenting scheduling changes, date/time updates, updating software in the individual scenting nebulizers, and firmware updates in the individual scenting nebulizers.

The nebulized oil output from a scenting nebulizer can either be input into the air passing through an HVAC system or can be sprayed directly into a room environment. Scenting nebulizers that are connected to an HVAC system are wired to be energized and spray nebulized scenting oil into the airflow only when the HVAC fan is running.

DETAILED DESCRIPTION

A preferred embodiment of the novel scenting nebulizer115is shown in the Figures for the distribution by nebulization of scented oil and utilizing the novel capacitive liquid level sensor to monitor the level of scenting oil in a bottle203of the scenting nebulizer115. This level sensing is done without contacting the scenting oil, and also provides an appropriate oil level indication that is continuously monitored and used to prevent running out of scenting oil.

Referring toFIG. 1, the outer construction of scenting nebulizer115consists of a top or front cover100and a base housing200, both made of metal with a special chemically resistant powder coating. Top cover100is removed from bottom200by removing screws112such as those shown through the edges of top cover100as shown inFIG. 1. Localized user programming of the operation of a scenting device115is accomplished by using a membrane keyboard108and an LCD display107. Display107may also be used to display information about the rate at which nebulized scenting oil is being dispensed from the scenting nebulizer115and other pertinent information. A hinged door109is secured with a lock111and allows internal access by maintenance personnel. Scenting oil fluid level can be seen though the clear plastic window110. A clear plastic bottle of scenting oil is mounted inside nebulizer115right behind door109. Connections to scenting nebulizer115consist of (1) a conventional wired LAN connector101for connecting a scenting nebulizer115to a local area network in a building or a group of buildings or connecting the scenting nebulizer115to the Internet via a LAN cable as shown inFIG. 4for remote monitoring and control of nebulizer150, (2) an antenna102for wireless connection of a scenting nebulizer115to the local area network in a building or a group of buildings or connect the scenting nebulizer115to a wireless router for connection to the Internet, (3) a 2-pin connector103for input control, (4) a power switch104to turn the unit on and off, and a power jack105for connecting an external power supply other than hardwiring power to nebulizer115. The scenting nebulizer115may have an internal battery or an internal power supply wired to AC power. A nebulized oil output barb106is connected to a short tube (not shown) to feed nebulized scenting oil into an HVAC system for distribution, or feeding the nebulized scenting oil directly into a room.

The scenting nebulizer115of the preferred embodiment of the invention utilizes a pressurized air pumping system as shown inFIG. 2for the nebulization and distribution of scented oil in clear plastic bottle203. The integrated electronics section consists of a printed circuit card201that is mounted to the bottom metal work200. Connections consist of a wired LAN connector101, an antenna102for wireless connection to the internet, a 2-pin connector103for input control, a power switch104to turn the unit on and off, and a power jack105for connecting an external power as described in the previous paragraph as previously described with reference toFIG. 1. The scenting oil bottle203attaches to a nebulizer mechanism202by a threaded connection (not shown). Nebulizer202includes an air pump300for providing pressurized air into scenting oil bottle203. The pressurized air forces scenting oil out of bottle203which is nebulized by nebulizer202in a manner well known in the art. The nebulized oil is expelled out of hollow output barb106to be distributed into the immediate surrounding area as desired by an operator of the system. Alternatively, the nebulized oil output at barb106is input to a hose connected to barb106and the nebulized oil is fed into the duct work of a central air-conditioning and heating system (not shown). Scenting oil bottle203is preferably round and one attaches to nebulizer202by being threaded thereon. However, bottle203may have a square or rectangular cross-section and may be fastened to nebulizer202in a different way.

As shown inFIG. 3, the scenting nebulizer115of the preferred embodiment of the invention comprises a printed circuit card201with a specialized microprocessor708thereon and a capacitive scenting oil level sensory array302. Capacitive level sensor array302is shown and described in greater detail with reference toFIG. 6. Sensor array302is connected to a specialized microprocessor708and the two components provide multi-channel capacitive oil level sensing and oil level reporting to display107(FIG. 1) and to a remote central computer402(FIG. 4). The printed circuit card201is attached to the bottom housing200using standoffs as shown. On the printed circuit card201are etched copper pads and guard rings301that are part of capacitive sensor array302which are shown in and described in greater detail with reference toFIG. 6. The air pump300feeds high pressure air into the scenting nebulizer202that pressurizes scenting oil bottle203. The air pressure causes scenting oil exiting bottle203to be nebulized in a manner known in the art and the nebulized oil is output from the scenting nebulizer at oil output barb106. The nebulized oil is input directly to a room or via a hose into the duct work of an HVAC system.

FIG. 4is a block diagram showing a configuration in which a network of scenting nebulizers115are connected by either: (1) a wired or wireless local area network400to a centralized computer for402, or (2) via the Internet401to centralized computer402. The scenting nebulizers115may all be located in one location, or may be spread out over many locations across a city, across a state or across a country. The scenting nebulizers115are connected via a wired or wireless LAN400to central computer402(not shown) or LAN400may be connected via Internet401to central computer402.

Central computer402operates under the control of control software403which is stored in a storage device404along with scented oil level readings periodically received from all the scenting nebulizers115. Other operational information about the individual scenting nebulizers115is also stored in storage device404, along with any error information received from any of the nebulizers150. That is, central computer402is used to manage a network of a plurality of scenting nebulizers115on a one-to-one basis, all at the same time. The scenting nebulizers115are controlled by central computer402running the control software403in storage device404. More particularly, using central computer402scenting schedule changes, date/time updates, scenting scheduling etc. may be made to individual scenting nebulizers115. In addition, operational software updates and firmware updates may be made to specific ones of the individual scenting nebulizers115. The control software403stores all scenting units100telemetry in a database404format.

Control software403running on computer402generates a control display interface such as shown inFIG. 5. The display consists of display fields that display stored operational information about each of the plurality of scenting nebulizers115connected to computer402via the previously described network. The display fields include Customer Tab504, LCD Tab501and Activity Tab502. The Unit Tab500is the main software control interface that has sections that control Unit Information505, display remote Oil Level506, Unit Network Settings507, Connect-Back Settings503, Schedules508& Proxy Settings509. Using computer402running control software403at a central location an operator may monitor and control a number of scenting nebulizers115all located within one physical location, or a number of scenting nebulizers115distributed throughout a number of remote locations across a city, state or country.

InFIG. 6is shown an enlarged version of the sensor pads302a-eand guard rings601a-eshown in and briefly described with reference toFIG. 3. Shown are five sensor pads302athrough302ethat are etched onto printed circuit board201(FIGS. 2 and 3) and are used as part of the capacitive liquid level sensing in accordance with the teaching of the invention. Each one of the five sensor pads302a-eis one plate of a capacitor that makes up a capacitive scenting oil level sensor. These five sensor pads302a-eare positioned on printed circuit board201(FIG. 3) to be closely alongside, and possibly touching, scenting oil bottle209as shown inFIG. 3. Each of these etched square copper sensor pads302a-eis 8 millimeters square and they are center-to-center spaced 18 millimeters from each other as shown. Surrounding each sensor pad302a-eis an etched square guard wall601a-e. These guard walls601are each 18 millimeters on a side with vertically adjacent sensor pads302sharing a common guard wall601as shown. The width of the etched guard walls601is 0.050 inches. This leaves a space602around each of the sensor pads302. All the guard walls601are connected to an electrical ground. The guard walls601a-eminimize or prevent electrical interference between adjacent sensor pads302a-eand they also help shape an electric field emanating from each sensor. The purpose of the electric fields is described further in this detailed description. Also not shown inFIG. 6are etched copper paths or traces that connect all five sensor pads302a-eto a multi-channel, special purpose capacitive sensor microprocessor704as shown inFIG. 7. Specialized microprocessor704is a Microchip CAP1298 Capacitive Touch Sensor. However, and most importantly, in the scenting nebulizer115microprocessor704is not used as a touch sensor.

Over the top of the sensors302a-e, guard walls601and printed circuit board201on which the sensors and guard walls are located, is deposited a 0.002 inch thick layer of solder mask. On the printed circuit board201on which sensor pads302and guard walls601are etched there is no copper layer beneath the pads and guards serving as a ground plane.

The guard walls601a-eare connected to electrical ground to minimize the electric fields generated by any one of the sensor pads302a-efrom interfering with the operation of an adjacent sensor pad as a plate of a capacitive touch sensor.

Referring briefly toFIG. 3, when the bottle203of scenting oil is mounted in scenting nebulizer115its outer wall touches or is within a few ten thousandths of an inch from sensor pads302a-e. When in operation, each of sensor pads302a-ehas an electrical potential applied thereto and from each of sensor pads302a-eemanates an electric field that is described in the next paragraph.

The five capacitors used for the novel capacitive oil level sensing, the capacitance values of which are measured by specialized microprocessor704, each comprise the following. One of the sensor pads302a-3acts as one plate of each of the five capacitors, the housing of scenting nebulizer115acts as the other plate of the same capacitor and is common for all five capacitors. The housing at ground potential. The dielectric of each of the five capacitors comprises the layer of solder mask over the associated one of the sensor pads302, the walls of bottle203, and the scenting oil in the bottle203. Thus, there are five capacitors formed. It is the value of each of these five capacitors that is individually measured by specialized microprocessor704as a dielectric values changes when the level of the scenting oil in bottle203goes down. The electric field generated during operation of each of the five capacitors emanates from each of sensor pads302a-epasses through the layer of solder mask over each sensor pad, through the wall of bottle203and through any scenting oil therein and terminates in the housing of scenting nebulizer115. Accordingly, as the level of the scenting oil in bottle203goes down in front of each of the sensor pads302the value of the dielectric in front of the pads changes. This changes the value of the capacitor which is measured and capacitive oil level sensing is achieved.

FIG. 7is an electrical block diagram circuit of a single scenting nebulizer115(FIG. 4). Shown are the five sensor pads302a-e(FIG. 6) that are connected to a multi-channel capacitive touch sensor microprocessor704. Microprocessor704is a specialized processor Microchip CAP1298 Capacitive Touch Sensor. However, and very important, in the scenting nebulizer115microprocessor704is not being used as a touch sensor. Microprocessor704measures the value of capacitance of each of five capacitors of each of which one of sensor pads302a-eis a part. Specialized microprocessor704is connected to another microprocessor708inside the scenting nebulizers115and the capacitance values, and any changes therein, are forwarded via leads706to microprocessor708.

Specialized microprocessor704(Microchip CAP1298) is programmed to measure the capacitance of each of the five capacitors formed by each of sensor pads302a-eonce every second. However, the sampling time rate may be increased. These capacitance readings are forwarded via leads706to microprocessor708. There are two fundamental methods for detecting a shift in capacitance using a microprocessor. The first is to use a voltage measurement where the system manipulates the pin of the sensor, to place a voltage based on the amount of capacitance on the pin, and looks for a shift in the voltage reading on the sensor. This includes methods such as Microchip's Charge Time Measurement Unit (CTMU) and Capacitive Voltage Divider (CVD). The alternative is to measure the sensor using a frequency approach which uses a pseudo-randomized frequency to sense changes in capacitance.

When a full bottle203of scenting oil is first installed in a scenting nebulizer115the capacitance values measured for each of the five capacitors is averaged and stored as a figure indicating there is the maximum amount of oil in front of each of sensor pads302a-e. The full bottle203yields a maximum capacitance measurement for each of the five capacitors and is referred to as “max value” in this description. Similarly, when there is no bottle or an empty bottle203positioned in nebulizer115it yields a minimum capacitance measurement for each of the five capacitors and is referred to as “min value” in this description.

As the scenting oil in bottle203is used up the level of scenting oil in bottle203goes down. When this happens, the amount of scenting oil in bottle203in front of each of the sensor pads302decreases, starting with the uppermost sensor pad302aand going to the lowermost sensor pad302e. That is, as the scenting oil is used up, there is sequentially no scenting oil in front of the capacitors utilizing sensor pads302a-e. Thus, the value of the dielectric in front of each of the five capacitors sequentially changes and the change is sensed by the specialized microprocessor704that is periodically measuring the capacitance of each of the five capacitors. In actual operation of a scenting nebulizer115the capacitance values determined every second by microprocessor704are forwarded via leads706to microprocessor708. Microprocessor708takes these capacitance readings for each of the five capacitors received over a small finite time period and averages them to calculate a capacitance reading that is stored. Each sequentially stored average capacitance reading is compared to the initially stored max value and min value capacitance figures and microprocessor708can then determine which of the five sensor pads302a-ethe scenting oil level is in front of. Microprocessor708also uses the stored max value and min value capacitance figures and interpolates an actual averaged, stored capacitance figure between these two values to mathematically determine the actual level of the scenting oil in front of a sensor pad302.

Thus, as the level of scenting oil in bottle203goes down microprocessor708mathematically determines by interpolation that there is no scenting oil in front of the uppermost capacitor of which sensor pad302ais part. This interpolation process is sequentially repeated for each of sensor pads302b-eas microprocessor708mathematically determines by interpolation the actual level of the scenting oil in front of a sensor pad302b-e.

Microprocessor708also interacts with specialized microprocessor704via control signals on leads707. These control signals indicate to microprocessor704how often the level of the scenting oil in bottle203should be capacitively measured and the level reading returned to microprocessor708. Further, microprocessor708provides display output signals to LCD display107via leads709, provides control signals to operate nebulizer air pump300via leads710, and receives control signals from keyboard buttons108on the front of each scenting nebulizer115via leads711.

In the networked configuration of scenting nebulizers115shown inFIG. 4microprocessor708in each of scenting units115forward their calculated scenting oil level readings via LAN leads400to remote processor402as described with reference toFIG. 4. Remote processor402utilizes these scented oil level readings to initiate maintenance action to replace an almost empty bottle203of scenting oil before it is fully emptied.

When a scenting nebulizer115is operating in a standalone manner local microprocessor708will initiate appropriate visual warnings/readings on display107(FIG. 1) of a scenting nebulizer115, and provide an audible signal when the level of the scenting oil gets too low.

While what has been described herein is a preferred embodiment of the invention those skilled in the art will recognize that numerous changes may be made without departing from the spirit and scope of the invention. More particularly, while the preferred embodiment of the invention described herein is used to measure the level of scenting oil in a scenting nebulizer the novel capacitive liquid level sensing may be utilized to measure the level of any type of liquid in a non-conductive container. In addition,