Key fob and system for indicating the lock status of a door lock

• US 7,898,382 B2
• Filed: 05/11/2006
• Issued: 03/01/2011
• Est. Priority Date: 05/11/2006
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hicks, Creighton Matthew, Berstis, Viktors
• Primary Examiner(s): Zimmerman; Brian A
• Assistant Examiner(s): Jiang; Yong Hang
• Application Number:
  US11/382,764
• Publication Number:
  US 20070262848A1
• Time in Patent Office: 1,755 Days
• Field of Search: 340/3.9, 340/426.15, 340/5.33, 340/5.42, 340/5.73, 340/5.72
• US Class Current: 340/3.9
• CPC Class Codes: G07C 2009/00984 fob
• CPC Class Codes: G07C 2209/62 Comprising means for indicating the status of the lock
• CPC Class Codes: G07C 9/00944 Details of construction or manufacture
• CPC Class Codes: G08B 21/18 Status alarms G08B21/02 takes precedence

Abstract

The present invention provides a system that records, at a remote location, the current status of a door lock. This invention provides a key fob device, which records the current status of a door look. The key fob indicates to the user the current lock status of the given door(s) in question. The key fob is a small key chain attached device, which records the state of the door locks, or other devices or appliances, as one departs from the door. The system of the present invention comprises a sensor at the door that detects the current lock status of a door and transmits this lock to the key fob. Also incorporated into the key fob is circuitry that receives and records this received lock status. A display component in the key fob displays this current lock status when prompted by the user.

Claims

1. A method for remotely determining a status of a door lock comprising:

a receiver device receiving a broadcast signal from a broadcast device built into the door, said receiver device located remotely from the door, said broadcast signal comprising a door lock status consisting of the status of the door lock, said broadcast signal temporarily powering a trigger receive circuit in the receiver device;

said temporarily powered trigger receive circuit activating a main receiver circuit of the receiver device;

said activated main receiver circuit receiving the door lock status that is in the broadcast signal; and

said main receiver circuit storing the received door lock status in a memory location in the receiver device,

wherein the memory location consists of a first field and a second field, wherein the main receiver circuit comprises a logic circuit for performing said storing the door lock status in the memory device, wherein the logic circuit comprises a first AND gate and a second AND gate, wherein the first AND gate comprises a first input having a fixed value of 1, a second input, and an output coupled to the first field of the memory location, wherein the second AND gate comprises a first input having the fixed value of 1, a second input, and an output coupled to the second field of the memory location, wherein the door lock status in the broadcast signal is encoded in bits consisting of a first input bit of 0 or 1 and a second input bit of 0 or 1, and wherein the method further comprises;

said second input of the first AND gate receiving the first input bit received from the broadcast signal;

said first AND gate performing an AND of the first input bit and the fixed input of 1 at the first input of the first AND gate to generate a first output bit;

transmitting the first output bit from the output of the first AND gate to the first field of the memory location;

said second input of the second AND gate receiving the second input bit received from the broadcast signal;

said second AND gate performing an AND of the second input bit and the fixed input of 1 at the first input of the second AND gate to generate a second output bit;

transmitting the second output bit from the output of the second AND gate to the second field of the memory location.

2. The method of claim 1, wherein the first and second input bits are respectively either 0 and 1 or 1 and 0.

3. The method of claim 2, wherein the receiver device comprises a display circuit comprising a third AND gate, a fourth AND gate, a first pass transistor, a second pass transistor, a first light and a second light, wherein the third AND gate comprises a first input having the fixed value of 1, a second input, and an output coupled to an input of the first pass transistor, wherein the fourth AND gate comprises a first input having the fixed value of 1, a second input, and an output coupled to an input of the second pass transistor, wherein an output of the first pass transistor is coupled to an input of the first light, wherein an output of the second pass transistor is coupled to an input of the second light, wherein the receiver device is a key fob device comprising a display button which if pressed causes the door lock status in the memory location to be displayed, and wherein the method further comprises:

in response to the display button having been pressed, said second input of the first AND gate and said second input of the second AND gate receiving the first output bit and the second output bit from the first field and the second field of the memory location, respectively;

said third AND gate performing an AND of the received first output bit and the fixed input of 1 at the first input of the third AND gate to generate a third output bit;

transmitting the third output bit from the output of the third AND gate to the input of the first pass resister;

(i) to cause, if the third output bit is 1, the output of the first pass resistor to open which triggers illumination of the first light and (ii) to cause, if the third output bit is 0, the output of the first pass resistor to close to which prevents illumination of the first light;

said fourth AND gate performing an AND of the received second output bit and the fixed input of 1 at the first input of the fourth AND gate to generate a fourth output bit;

transmitting the fourth output bit from the output of the fourth AND gate to the input of the second pass resister;

(i) to cause, if the fourth output bit is 1, the output of the second pass resistor to open to which triggers illumination of the second light and (ii) to cause, if the fourth output bit is 0, the output of the second pass resistor to close which prevents illumination of the second light.

4. The method of claim 1, wherein the broadcast signal further comprises a time at which the door lock status changed from a prior status of the door.

5. The method of claim 1, wherein the receiver device is a key fob device configured to be attached to a key chain along with keys of a user, key fob device having objects comprising a first light which if illuminated indicates that the door is locked, a second light which if illuminated indicates that the door is unlocked, a first button which if pressed unlocks the door, a second button which if pressed locks the door, a third button which if pressed opens the door, a fourth button which if pressed closes the door, a display button which if pressed causes the door lock status in the memory location to be displayed via illumination of the first light or the second light, and a panic bar which if pressed activates an alarm function, and wherein the method further comprises displaying the door lock status in response to the display button having been pressed.