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CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This is a non-provisional application based upon U.S. provisional patent application Ser. No. 60/579,743, entitled “PET DOOR”, filed Jun. 15, 2004. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a pet entrance door, and, more particularly, to an automated pet entrance door.  
         [0004]     2. Description of the Related Art  
         [0005]     Pet doors are known in the art, which include flexible flaps over an opening in a wall or door to allow a pet to have access to a house. The pet normally presses against the flexible flap allowing the pet to displace the flap and enter the house. The flap is non-insulated and can be very uneconomical during inclement weather. This sort of pet door offers little or no security, allowing other animals or even people to have access to the home.  
         [0006]     Pet doors available on the market today often consist of a soft plastic or aluminum material, which hang by gravity, typically in a swinging manner and are sealed by a magnetic device. Other doors have an overlapping of plastic material in such a way as to prevent excessive weather penetration. These sorts of pet doors operate by way of the pet having to push against the door or flap with its head in order to enter or exit.  
         [0007]     Automatic opening doors for pets are also known, which lock when closed to prevent unauthorized access into a home.  
         [0008]     What is needed in the art is a pet door that controls access yet reduces the amount of air that enters or exits the home.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention provides a pet door that retracts based upon identification of the pet.  
         [0010]     The invention comprises, in one form thereof, a pet door system including a door, a detection device, a receiver, a motor and a controller. The detection device detects the proximate presence of a pet to the door. The receiver receives an identification signal that establishes an identity of the pet. The motor is operatively connected to the door. The controller is communicatively coupled to the detection device, to the receiver and to the motor. The controller issues a signal to the motor to open the door based upon the identity of the pet.  
         [0011]     An advantage of the present invention is that the pet door is opened based upon the identification of an approaching animal.  
         [0012]     Another advantage of the present invention is that the system easily learns the identification of a new pet.  
         [0013]     Another advantage of the present invention is that controllable entry of the pet is maintained on a scheduled basis. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:  
         [0015]      FIG. 1  is a front view of an embodiment of the pet door of the present invention;  
         [0016]      FIG. 2  is a partially sectioned side view of the pet door of  FIG. 1 ;  
         [0017]      FIG. 3  illustrates, in a cross-sectional manner, a portion of the upper part of the pet door of  FIGS. 1 and 2 ;  
         [0018]      FIG. 4  is another view of  FIG. 3  with the door retracted;  
         [0019]      FIG. 5  illustrates the installation of the pet door of  FIGS. 1-4  in a residential door;  
         [0020]      FIG. 6  illustrates an embodiment of a method of operation of the pet door of  FIGS. 1-5 ;  
         [0021]      FIG. 7  is a continuation of the method of  FIG. 6 ; and  
         [0022]      FIG. 8  is an embodiment of a method to confirm the identification of a pet proximate to the pet door of  FIGS. 1-5 . 
     
    
       [0023]     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one preferred embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0024]     Referring now to the drawings, and, more particularly to  FIGS. 1 and 2  there is shown a pet door assembly  10  including an inner frame  12 , an outer frame  14 , a door assembly  16 , a control assembly  18 , a power source  20  and a door flap  22 . Inner frame  12  and outer frame  14  are mounted on opposite sides of a door or wall and extend beyond the opening therein. Inner frame  12  and outer frame  14  are fastened together through the intervening structure by way of screws or other fasteners that go through the opening in the wall or door, without the need to drill additional holes in the wall or door.  
         [0025]     Door assembly  16  is a segmented door  16  including slats  24 , a roller tube  26 , a motor  28 , a slat scroll  29 , tracks  30 , and a brush seal  32 . Slats  24  are linked together in a rolling manner along the edges of each slat  24 . Slats  24  are segments that are interconnected yet are able to be wound around roller tube  26 . As shown in  FIGS. 3 and 4 , slats  24  have a cross sectional shape with a hollow interior defining a thermally insulative air gap. Motor  28  is connected to roller tube  26 , which supplies power for the rotation of roller tube  26  to thereby wind slats  24  therearound when door assembly  16  is in an open position. Slat scroll  29  guides slats  24 , particularly when they unwind from roller tube  26 , by directing slats  24  toward tracks  30 . Tracks  30  on each side of frames  12  and  14  allow slats  24  to be retained in a substantially vertical manner as door assembly  16  moves slats  24 . A brush seal  32  is located along a proportion of outer door frame  14  to seal the mechanism of door assembly  16 , to thereby exclude insects and the of air therethrough.  
         [0026]     Control assembly  18  includes an operator interface panel allowing an operator to energize the control circuits of assembly  10  and to designate which transmitters  40  will function with assembly  10 . Control assembly  18  can also select the amount of time that door assembly  16  is in an open position and the proximity of transmitter  40  to which control assembly  18  should respond. Further, control assembly  18  can be utilized to establish a schedule as to when a transmitter  40  will or will not trigger the opening of door assembly  16  when transmitter  40  is proximate to door assembly  10 . Control assembly  18  includes an interface to communicate with a home security system so that the home security system can use information from control assembly  18  to sound a chime indicating that door assembly  16  is open, or to alter the type of detection features the security system utilizes if the door is open or closed, and even to indicate that all of the pets are outside. Additionally, if door assembly  16  is breached by a person trying to enter the house this information is passed along to the home security system. The interface also allows the security system to provide information to control assembly  18  to allow it to alter its operations. For example, if a fire is detected by the security system, then door assembly  16  will only open if a pet wants out and will not allow a pet to enter the house. Also, if the security system detects movement, which may indicate an unauthorized person in the house, control assembly  18  may allow certain pets to leave and others, such as a guard dog, to enter the house.  
         [0027]     Power source  20  includes batteries, which provide a DC power source to power motor  28  under the control of control assembly  18 . Additionally, an AC power source may be utilized to provide power to pet door assembly  10 .  
         [0028]     Flexible door flap  22  is positioned along one side of door assembly  16  to provide a further barrier for the movement of air through an opening in assembly  10 . When a pet wearing transmitter  40  approaches pet door assembly  10  and door assembly  16  is open, door flap  22  reduces the air movement through the opening until the pet passes through the opening. Door flap  22  may be removable.  
         [0029]     Transmitter  40  is worn on a pet, preferably on a pet collar, and provides an identification signal, in the form of a keyed transmission, which is detected by door assembly  10  and decoded by control assembly  18  to decide whether or not to open door assembly  16 , thereby providing a keyed entry system. A plurality of transmitters  40  may be utilized with control assembly  18  containing information as to which transmitters  40  are to effect the opening of door slats  24 .  
         [0030]     Assembly  10  can also be thought of as a security shutter  16  that automatically opens and closes when a pet approaches to allow access to an outside or an inside area. Soft flap  22  adds additional protection from the elements while shutter  16  remains open. Shutter  16  provides security, insulation and a weather-proof seal. Control assembly  18  includes circuitry, software and an operator interface, for optical, radio frequency or an RFID interface. The software is used to identify the Identification of the pet and to determine if and when to open and close shutter  16 .  
         [0031]     The activation of door assembly  10  is accomplished by way of transmitter  40  or an RFID added to a pet&#39;s existing collar. Assembly  10  receives a signal from transmitter  40  when the pet is within a preset range, typically  16 - 36  inches, and the door opens by the activation of motor  28 . Motor  28  causes roller tube  26  to rotate, onto which slatted door assembly  16  is wound and unwound. Door assembly  16  remains in an open position for up to five seconds after transmitter  40  is out of range. The user can adjust the range and timing of the door opening by way of control assembly  18 . Control assembly  18  may additionally include a battery life indicator.  
         [0032]     If transmitter  40  transmits an RF signal, a replaceable battery will be utilized to supply power to transmitter unit  40  on the pet&#39;s collar. Alternatively, RFID technology can be utilized to provide identity information relative to the particular pet approaching door assembly  10 .  
         [0033]     Software within control assembly  18  monitors the battery voltage and when the battery voltage drops to a certain level, the door will not activate to the rollup position. This safety feature prevents the door from remaining in an open position due to a low battery condition. The battery life indicator informs the user of the low battery condition. Additionally, a light curtain or IR screen will sense obstruction in the opening to prevent door assembly  16  from closing if an obstruction is in the opening. Additionally, if the door assembly should contact an item preventing complete closure of the door, the door assembly will reverse to the open position and sound an alarm until the obstruction is removed.  
         [0034]     Now, additionally referring to  FIGS. 3 and 4 , there is shown, in  FIG. 3 , a view of slats  24  in an extended closed position, and slats  24  are wound onto tube  26  when door assembly  16  is in an open position as shown in  FIG. 4 .  
         [0035]     Now, additionally referring to  FIG. 5  there is shown a view of door assembly  10  installed in a residential door  42 . The advantage of installing door assembly  10  in residential door  42  is that access on both sides of door  42  is normally maintained so that the pet can approach from either side without difficulty.  
         [0036]     Electronic device assemblies  44  and  46  include a passive detection device, suitable for detecting the presence of a pet, such as, an infrared motion detection device. Also contained within assemblies  44  and  46  is a receiver and transmitter used to query transmitter  40 . Transmitter  40  may be an RFID device, which responds to a level of impinged electromagnetic radiation and may be considered a transponder  40 . The passive detection devices in assemblies  44  and  46  detect the presence of an animal, then the transmitter in the respective assembly  44  or  46  sends a signal or radio frequency power signal, which can cause an RFID device to function. The RFID device may be attached to a collar on the pet or subcutaneously located just beneath the skin of the pet. Transponder  40  returns a signal that is received by the receiver in assembly  44  or  46 . The signal contains an identification of the device that is associated with a particular pet. The pet is identified as one being allowed to enter or exit the home and a determination is made by control assembly  18  as to whether the pet is blocked from exiting or entering the home based on other criteria such as a timing schedule associated with when the pet can enter or exit the home. Motor  28  is activated by way of a signal from control assembly  18  causing slats  24  of door assembly  16  to be wound upon roller  26  to allow movement of the pet through the doorway.  
         [0037]     Electronic assembly  44  and/or  46  may include a passive infrared device (PIR) and/or an RFID antenna that has a magnetic tuning mechanism. The mechanism uses a magnet to alter the permeability of an inductor core in order to alter the value of the inductor for tuning purposes. The magnetic tuning method provides at least a  5 : 1  change in inductance, which is over  20  times more range than can be done with a low loss pot core. This range of tuning allows a lot of variation in the methods of antenna construction and mounting techniques. The mechanism allows for the tuning mechanism to be cast into the plastic of frame  12  and/or  14  and allow the positioning of the in terminals of the inductor to be positioned on a printed circuit board.  
         [0038]     Transponder  40  contains an electronic ID, which must be recognized by the electronics in control assembly  18  as belonging to a pet authorized to open door assembly  16 . Control assembly  18  may be programmed to accept multiple pet IDs and to specify the allowable entry/exit patterns for each individual pet. The entry/exit pattern for each pet may each relate to numerous variables such as the day of the week, the time of day, the temperature, the weather conditions and/or the number of uses of the door in a specific time period.  
         [0039]     As the pet enters through the door opening, a transition detection device  48 , which may be in the form of an ultrasonic detector  48  or an infrared light curtain  48 , detects the presence of the pet as it is transiting the doorway and provides this information to control assembly  18  to prevent door assembly  16  from closing on the pet. Once the pet has transited the doorway, door assembly  16  is closed by operation of motor  28  unrolling slats  24  from roller  26 , thereby closing retractable door assembly  16 . If the pet approaches pet door assembly  10  and door assembly  16  is opened but the pet does not enter through the passageway after a predetermined time, door assembly  16  is closed.  
         [0040]     Now, additionally referring to  FIGS. 6-8 , there are illustrated embodiments of methods to operate pet door assembly  10 . In particular, a method  100  which illustrates the control of door assembly  16  exerted by control assembly  18  and method  200  illustrates a method of confirming the identification of the pet. Method  100  starts at step  102  and proceeds to either step  104  or  106 . Steps  104  and  106  are substantially similar and step  104  corresponds to the detection of an infrared signal by an infrared detector in electronic assembly  44  and step  106  corresponds to the detection of an infrared signal by an infrared detector in electronic assembly  46 . If either the infrared detector in assembly  44  or  46  are triggered, then the respective step  104  or  106  proceeds to step  108 . At step  108  a confirm ID method is executed, which will be explained later as method  200 . As a result of executing step  108  a result is returned from method  200 , which indicates that an ID is confirmed or an error signal is returned. If an error signal is received then the method proceeds to step  110  and the infrared signals from electronic assemblies  44  and/or  46  are masked for a predetermined time. This predetermined time is selected so as to prevent a pet from repeatedly triggering control assembly  18  to open door assembly  16 . Once the predetermined time has expired, the method returns to steps  104  and  106 .  
         [0041]     If a confirmed ID signal is returned, at step  108  then door assembly  16  is unlocked and a signal is sent to motor  28  to open door assembly  16 , at step  112 . A delayed door status is determined, which is a determination of the status of the door after a predetermined time and if the door is not open method  100  proceeds to point B in  FIG. 7 . If the delay door status, at step  114  indicates that door  16  is open then motor  28  is stopped, at step  116 . After another predetermined time, as indicated at step  118 , is waited then it is determined if light curtain  48  indicates that the light beam is clear, which indicates that the doorway is free of obstructions and then a short delay is waited to ensure clearance of the pet through the doorway at step  122 . Once the delay is completed the method continues to point A in  FIG. 7 . If the delay is not over the method returns to step  120  to again determine if light curtain  48  indicates a clear doorway. If at step  120  the beam of light curtain  48  is not clear then a delay is reset at step  124 . If the beam of light curtain  48  is broken greater than a predetermined time then an alarm, at step  128  is sounded to motivate the pet to move one way or the other. The alarm can also alert the homeowner that the door has been opened greater than a predetermined time and that something is blocking the doorway. If the beam has not been broken for greater than predetermined time then the process returns to step  120 .  
         [0042]     Once the delay is over at step  122  motor  28  is operated to close the door, at step  130 . If something acts to disrupt light curtain  48 , at step  132  then motor  28  is stopped at step  134 . The method then returns to step  112  on  FIG. 6 . If the beam of light curtain  48  remains clear then there is a current and delay check that is undertaken, at step  136 . A current check of the power being supplied to motor  28  is done to indicate if a load on the motor exceeds that required for normal operation. If the current being drawn by motor  28  exceeds a predetermined amount, it may be indicative of a problem in closing door assembly  16  or that something is blocking the closing of door  16 . Also if the closing of door  28  takes longer than a predetermined time, this may also indicate a problem. As such, either indicator of a problem causes the motor to stop at step  146 . An error flag is set in control assembly  18 , at step  148  and an alarm is sounded at step  150 . The alarm remains on until the alarm is reset, at step  152  and method  100  is completed and is restarted back at starting point  102 .  
         [0043]     If the current and delay check indicates that pet door assembly  10  is O.K. then door status sensors (not shown) are checked at step  148  to determine if door assembly  16  is open or closed.  
         [0044]     If door assembly  16  is open the method returns to step  132  and if the door status indicates that the door is closed then motor  28  is stopped at step  140 . Once motor  28  is stopped door assembly  16  is locked, at step  142 . Once a pet enters or exits the home it may quickly decide to return;  
         [0045]     however, at step  144  the opposite infrared detector in electronic assembly  44  or  46 , which is opposite the one utilized to open the door in the most recent opening is masked a predetermined time, to prevent the pet from reinitiating the opening of door assembly  16 . The predetermined time can be selected at control assembly  18  and can be separately assigned for each side of the door. For example, if it is desirable to let the pet always exit at any time then the predetermined time for the infrared mask associated with electronic assembly  44  (the one on the inside of the home) would be minimized or even set to zero. However, the predetermined time associated with the mask for electronic assembly  46  may be set for a much longer time, such as one minute. In this way the pet can exit at any time but is not allowed to return for at least one minute after going outside. After the predetermined time, method  100  ends and restarts at starting point  102 .  
         [0046]     In  FIG. 8  there is illustrated a method of determining the identification of the pet, including steps  202  through  234 . It will be understood that when the ID confirm error signal is generated at steps  226  or  232  that is the signal that is returned as an error in method  100  at step  108 . Conversely, when the ID is confirmed, such as at steps  216  and  234  then an O.K. signal is returned to step  108  of method  100 .  
         [0047]     Although an RFID transponder  40  is illustrated in method  200 , the technique can be easily adapted to an RF receiver transmitter  40 . At step  202  an RFID reader in either assembly  44  or  46  is powered on in order to ready the reader to receive a signal from transponder  40  associated with the pet. A transmission is sent to transponder  40  which will either serve to power the transponder  40  and/or cause it to send an identification signal to be read by the RFID reader. Once transponder  40  has been charged for a short period of time such as 50 milliseconds, at step  204  a signal, that contains an identification code (ID) of transponder  40 , is sent to electronic assembly  44  or  46 . If, at step  206 , an RFID reading is detected then the RFID CRC is checked at step  208 . If the CRC indicates that the RFID was not of an acceptable format or indicates an error in the signal then if the detected identification code is to be deleted at step  218  the process continues to step  220 . If the unit is not to be deleted at  218  then an ID confirm error is sent from method  200  at step  226 .  
         [0048]     If it is indicated that transponder  40  is to be deleted then the identification code that is contained in the acceptable list of identifications in control assembly  18  is deleted at step  220  and a sound issued at step  222 . If the operator indicates that it is O.K. to delete the identification code, at step  224 , then the identification code is deleted from the acceptable list and method  200  ends.  
         [0049]     If the check of the RFID format, at step  208  indicates that the RFID is of a proper format then if there is an indication in control assembly  18  that places control assembly  18  in a programming mode, so as to incorporate a new pet identification code into the acceptable list of pets that may enter through door assembly  16 , then the ID is registered at step  212  and a sound is issued at step  214  to indicate its acceptance as a newly programmed ID and an O.K. is issued at step  216 , which also returns an O.K. to method  100  at step  108  and method  100  proceeds to unlock and open the door. If there is no indication on control assembly  18  that the unit is being programmed then, at step  210 , method  200  proceeds to check the ID received from transponder  40  against a list of acceptable IDs, at step  228 . If the pet is not authorized to enter the home then method  200  proceeds to step  232  and returns an ID confirm error to method  100 . An additional check is made at step  230  to determine if the pet has been temporarily blocked from entering the home. In other words the pet may have an acceptable ID to normally operate the door assembly  16 , but is currently being blocked from activating the door. A pet may be temporarily blocked from leaving the home even though the pet ID is included as one authorized to enter or exit, which may be due to a scheduling sequence in control assembly  18 . For example, the pet may be allowed to enter the home in the evening hours but will not be allowed to leave until a certain time in the morning. If there is no blocking of the pet ID, then method  200  returns an ID confirm O.K. at step  234 .  
         [0050]     Advantageously, the methods of the present invention has a learning mode where IDs may be entered to allow pets to pass through the doorway. This learning mode allows the RFID system to query a proximate RFID device to obtain the ID therefrom, which is then entered into the list of acceptable IDs. Also, the scheduling of the access of the pet is controlled. The present invention also takes advantage of RFID systems for the identification of the pet.  
         [0051]     While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

Summary:
A pet door system including a door, a detection device, a receiver, a motor and a controller. The detection device detects the proximate presence of a pet to the door. The receiver receives an identification signal that establishes an identity of the pet. The motor is operatively connected to the door. The controller is communicatively coupled to the detection device, to the receiver and to the motor. The controller issues a signal to the motor to open the door based upon the identity of the pet.