Patent Publication Number: US-9428897-B2

Title: Touchless activation of a toilet

Description:
RELATED APPLICATION 
     The present invention claims priority to U.S. Provisional Patent Application 61/738,210, entitled “Touchless Activation of A Flush Toilet”, filed Dec. 17, 2012, the entire disclosure of which is incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to systems that cause a toilet to flush without a user having to touch the toilet, or touch objects mounted on the toilet. 
     BACKGROUND OF THE INVENTION 
     Many sensor systems currently exist for causing toilets or urinals to flush when a user moves away from them. In addition, sensor systems currently exist to cause faucets to turn on when a user&#39;s hands move towards them. However, the biggest problem with these sensors is that they use infrared sensing. 
     Infrared sensing has many drawbacks. For example, infrared sensing is affected by ambient light levels, the color or surface texture of the object that reflects the light, and even the room temperature. In fact, a user&#39;s shadow cast inadvertently over the sensor can cause it to function at the wrong time, or not function at all. 
     Any of these above factors can affect the timing of the actuator triggering, and whether or not the actuator even triggers. As any person who has used public bathrooms can attest, the automatic flushing of the toilet or the automatic turning on of the faucet at the counter can be unpredictable. All too often, the toilet flushes too quickly or not at all, and the user is later waving their soapy hands under the faucet in an attempt to turn it on. 
     What is instead desired is an activation sensor system that is reliable and is not affected by changes in ambient light, reflecting surface colors or textures or inadvertent shadows being cast over the sensor. It is also desirable that such system be cost effective such that it can be incorporated into residential toilet designs when a “touchless” flushing would be desired. As will be explained, the present invention provides such a solution. 
     SUMMARY OF THE INVENTION 
     The present invention provides a system that uses an ultrasonic sensor to trigger the flushing of a toilet (or activation of some other device or appliance). The advantages of using an ultrasonic sensor (to preferably detect the presence of a user&#39;s hand close to a sensor) include the fact that ultrasound is not affected by ambient light levels. In addition, ultrasound is not affected by the color of the user&#39;s clothing that it reflects off of; nor is it affected by the surface texture of the user&#39;s clothing. Ultrasonic sensors are also less sensitive to temperature variations temperature. Yet another advantage of ultrasonic sensors in general is that they don&#39;t require optical lenses. 
     The present ultrasonic sensor is preferably configured to detect an object. An advantage of ultrasonic detection (as compared to infrared detection) is that ultrasonic detection can offer distance detection. Therefore, ultrasonic detection can be used to determine the distance of the object where the infrared sensing is used to detect the presence of the object. The present system can therefore be calibrated such that a static (i.e.: non-moving) object in the sensing field (such as a shower curtain or cabinet) does not trigger the flush activation. In one optional preferred embodiment, the ultrasonic sensor is configured to detect objects at a near distance (while the infrared sensor will detect the object at a far distance). As such, the toilet only flushes when the user&#39;s hand is positioned quite close to the sensor switch on the side of the toilet. The more precise the sensing range and sensitivity of the detection method, the more accurate the activation signal will be. Therefore, the toilet will flush only when desired. Moreover, another advantage of using an ultrasonic sensor is that it allows for “ranging” (i.e.: determining the distance from an object to the sensor). An ultrasonic sensor can therefore reliably determine whether the object is close or far from the toilet which may be useful if the sensor is to trigger different actions at different times depending on the location or movement of the user. Moreover, the ultrasonic detection (as compared to infrared detection) will advantageously be affected less by color or texture variations. This also improves system reliability. 
     Unfortunately, the only disadvantage with using an ultrasonic sensor (as compared to infrared sensors) is relatively higher power consumption. Specifically, if an ultrasonic sensor is battery powered, it may require the user to change batteries too frequently. The alternative to using battery power would be for the sensor system to be connected to a bathroom AC outlet. Unfortunately, many users would not opt for a toilet that has to be plugged into a wall power supply in their private residence. 
     Therefore, the present invention also provides a novel system of power conservation for the ultrasonic sensor. In brief, this system comprises using an infrared sensor in combination with an ultrasonic sensor wherein the ultrasonic sensor remains primarily in a (power conserving) “sleep mode” and is only awakened by the infrared sensor when the infrared sensor detects a user at a distance (for example, when the user enters the bathroom). In preferred embodiments, the infrared sensor is a “passive infrared sensor”. Such a passive infrared sensor offers the advantage of low power detection of thermal gradients (e.g.: a person or a hand), but do not offer proximity or distance information. Therefore, the present invention couples infrared sensing with the ultrasonic sensing system. Since the infrared sensor uses far less power than the ultrasonic sensor, the resulting system requires far less power than using an “always on” ultrasonic sensor. This both extends system battery life, and improves system performance (i.e.: thereby accurately triggering the flushing at the proper times). Moreover, the infrared sensor is ideally suited to detect a person&#39;s body or a person&#39;s hand since the infrared sensor will be detecting the heat given off by the person&#39;s body. Thus, the infrared sensor can first detect the presence of the user (by viewing a thermal gradient), with the awakened ultrasonic sensor then detecting the person&#39;s body or a person&#39;s hand at a close distance. 
     In preferred embodiments, the present invention provides a sensor and actuator assembly, comprising: (a) an infrared sensor configured to detect the presence of an object; (b) an ultrasonic sensor configured to detect the presence of the object, wherein the ultrasonic sensor remains in a sleep mode until awakened by a signal from the infrared sensor after the infrared sensor has first detected the presence of the object; and (c) an actuator mechanism that activates in response to a signal from the ultrasonic sensor that the ultrasonic sensor has detected the presence of the object. Preferably, the infrared sensor is configured to detect the presence of the object at a far distance and the ultrasonic sensor is configured to detect the presence of the object at a near distance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cutaway perspective view of a toilet with the present flushing sensor and actuator assembly mounted thereon. 
         FIG. 2  is a close up front perspective view of the sensor and actuator assembly. 
         FIG. 3  is a close up rear perspective view of the sensor and actuator assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
       FIG. 1  illustrates the placement of the present invention on a toilet. As will be explained, the present invention ideally provides a system for detecting the presence of a user&#39;s hand near a sensor to cause the toilet to flush. It is to be understood, however, that the present invention is not limited to systems for flushing toilets. For example, the present invention can also be used for flushing urinals, or for turning on a faucet at a sink counter. In fact, the present invention can even be used to activate, or turn on, any device or appliance, including but not limited to, bathroom and kitchen devices and appliances. The advantage of the present invention is that it provides “touchless” operation for the user. In other words, the user need not touch the toilet or any device mounted on the toilet to cause the toilet to flush. This, of course, improves hygiene, and is desirable both in public bathrooms and in in private residences. (Note:  FIG. 1  is a cut away view also showing internal components of the toilet, to illustrate flushing operation). 
       FIGS. 2 and 3  show close up perspective views of assembly  10 . Assembly  10  is received through a hole in the side of the toilet tank. Assembly  10  comprises a housing having an outer portion  12  disposed to protrude out of the side of the toilet tank wall, and an inner portion  14  disposed within the toilet tank. A screw cap  15  (positioned within the tank) can be rotated to tighten assembly  10  into the hole in the toilet tank. As such, the tank wall becomes sandwiched between screw cap  15  and the large radius flange  13  on outer portion  12 . Mid-portion  16  is dimensioned to fit snuggly in the hole passing through the tank wall. Thus, the radius of portion  16  is only very slightly smaller than the radius of the hole itself. 
     Sensor and actuator assembly  10  comprises an infrared sensor  20  and an ultrasound sensor  22 . It is to be understood that an “ultrasound sensor” as described herein preferably comprises an ultrasound transducer, being a membrane that is excited and resonates. This membrane receives sound energy and thus creates a voltage potential based on the amplitude of the sound pressure. Pushing pad  21  is a manual on/off switch that turns the entire system on and off. In addition, a manual flush activation button  23  is also provided (for example in the event of a power failure). 
     Infrared sensor  20  is configured to detect the presence of an object, and is used to “wake up” ultrasonic sensor  22 . During normal operation, ultrasonic sensor  22  is in a “sleep mode” such that system power consumption is significantly reduced. When a user enters the room, or moves close to the toilet, the infrared sensor  20  will detect the presence of the user. At this time, the infrared sensor  20  will then turn on ultrasonic sensor  22 , thereby awakening it from its sleep. Finally, when the user&#39;s hand is positioned close to the ultrasonic sensor  22  itself, a signal will be sent to an actuator mechanism that will trigger toilet flushing. In this way, the user&#39;s hand need only be positioned a few inches from the outer portion  12  of assembly  10  to cause the toilet to flush. The benefit of using an ultrasonic sensor at these close distances (as opposed to a standard infrared sensor, if an object is too close to the infrared sensor, then a user&#39;s hand may shade the sensor causing it to fail to detect the increase in reflected light. 
     In one optional embodiment, the actuator mechanism  30  will cause a solenoid (not shown) to move an internal plunger to move air through a pneumatic cable (or simply push or pull a physical cable), designated herein as element  32 . The movement of, or through, element  32  can be used to cause flush valve  34  to flush the toilet. It is to be understood that the structure of elements  32  and  34  is not limited to any particular embodiment or device. One example of a suitable activation mechanism (i.e.: a system comprising elements  32  and  34 ) is found in U.S. patent application Ser. No. 13/943,991, entitled “Toilet Discharge Valve Assembly Having Moveable Buoyant Float Therein”, filed Jul. 17, 2013, the entire disclosure of which is incorporated herein by reference in its entirety. The system disclosed in that patent application uses a switch (labeled as element # 42 ) to selectively open and close an air passageway to permit a buoyant float (covering a discharge valve) to lift and thereby flush the toilet. Any other device (including but not limited to a lever arm) may be part of actuator mechanism  30 . 
     Again, it is to be understood that the above flush valve  34  example is not limiting. Any suitable actuation mechanism may instead be used in accordance with the present invention. Moreover, actuator mechanism  30  could be an electrical actuator that turns on a power switch, a hydraulic actuator that turns on a faucet tap, or more generally, any actuation mechanism that activates any appliance or device. Different actuator mechanisms can be used such that the present invention can be tailored to the use of many different products. 
     In preferred embodiments, infrared sensor  20  detects the presence of the object at a far distance and ultrasonic sensor  22  detects the presence of the object at a near distance. The far distance can be up to ten or more feet, but could also be shorter distances like 0 to 24 inches, or even just 0 to 15 inches. It is to be understood that the present invention is not limited to any specific “far distance”. In various preferred embodiments, the near distance is preferably less than 8 inches. Most preferably, the near distance is less than 3 inches. The advantage of this configuration is that a reliable ultrasonic sensor system is used to detect the user&#39;s hand when the user&#39;s hand is within a few inches from assembly  10 . The advantage is that ultrasound detection is much more reliable than simple infrared detection (as was explained above). However, by relying on the infrared sensor to first detect the user entering the room, and then turn on ultrasonic sensor  22 , assembly  10  conserves the power required to operate ultrasonic sensor  22 . Moreover, the actuator mechanism  30  only activates after both the infrared sensor  20  and the ultrasonic sensor  22  have both detected the object. This further increases the reliability of the system. 
     In preferred aspects, actuator mechanism  30  comprises: a solenoid; a plunger rod in the solenoid, the plunger rod being moved by electric current passing through the solenoid; and a pneumatic tube or a connecting cable  32 . Movement of the plunger rod causes air to move in the pneumatic tube or wherein movement of the plunger rod moves the connecting cable, and wherein the movement of air in the pneumatic tube or the movement of the connecting cable causes flush valve  34  to cause the toilet to flush. Assembly  10  preferably comprises a housing  40 , wherein the infrared sensor  20 , the ultrasonic sensor  22  and the solenoid (not shown) are all disposed within (or on) the housing. 
     In preferred embodiments, assembly  10  further comprises a battery power supply canister  50  that supplies the power to both infrared sensor  20  and ultrasonic sensor  22 . Optionally, the battery canister  50  can be connected to housing  40  such that the battery canister  50  is also disposed within toilet tank. It is be understood, however, that the batteries can instead be disposed within the same physical housing as the infrared and ultrasonic sensors. 
     In preferred embodiments, assembly  10  further comprises a microcontroller (not shown) disposed within housing  40 . The microcontroller receives the signal from infrared sensor  20  that the object has been detected and then sends a signal to the ultrasonic sensor  22  to awaken the ultrasonic sensor from its sleep mode. 
     In some optional preferred embodiments, the present invention simply provides an ultrasonic sensor  22  configured to detect the presence of an object; and a flush actuator mechanism  30  that flushes a toilet in response to a signal from the ultrasonic sensor when the ultrasonic sensor detects the presence of the object. (In these embodiments, the infrared sensor is omitted, and the ultrasonic sensor remains on. These embodiments may be appropriate if the power drain on the battery pack is low enough or the power supply is high enough such that the ultrasonic sensor  22  can be left on at all times). 
     The present invention also provides a method of actuating a device by: 
     (a) detecting the presence of an object using infrared sensor  20  mounted on the device; (b) awaking an ultrasonic sensor  22  from a sleep mode after the infrared sensor  20  has detected the presence of the object, wherein ultrasonic sensor  22  is also mounted on the device; (c) detecting the presence of the object with ultrasonic sensor  22 ; and (d) activating an actuator mechanism  30  in response to the ultrasonic sensor detecting the presence of the object.