Electric appliance having a proximity sensor

• US 6,307,182 B1
• Filed: 04/25/1997
• Issued: 10/23/2001
• Est. Priority Date: 04/25/1997
• Status: Expired due to Term

• Current Assignee: Spectrum Brands, Inc. (Spectrum Brands Holdings, Inc.)
• Original Assignee: Toastmaster Incorporated (Spectrum Brands Holdings, Inc.)
• Inventors: Lile, Lawrence O.
• Primary Examiner(s): Walberg, Teresa
• Assistant Examiner(s): VAN, QUANG T
• Application Number:
  US08/845,702
• Time in Patent Office: 1,642 Days
• Field of Search: 219/257, 219/240, 219/518, 219/509, 219/251, 219/506, 219/241, 200/600, 307/116, 307/125, 307/652, 307/117, 307/326, 324/679, 324/686, 324/677, 324/678, 38/74, 38/82, 38/90, 153/19, 235/462.32
• US Class Current: 219/257
• CPC Class Codes: D06F 75/26 Temperature control or indicating arrangements
• CPC Class Codes: H03K 2217/960715 Rc-timing; e.g. measurement of variation of charge time or discharge time of the sensor

Abstract

An electric iron having a microprocessor-controlled relay which automatically connects an iron to and disconnects an iron from a source of electrical power based upon whether a user is grasping the handle of the iron and the position of the iron. The microprocessor is coupled to a proximity sensor comprised of a conductive sheet disposed within the iron handle, as well as a conventional orientation sensor. To determine whether a user is grasping the iron handle, the microprocessor detects the amount of time required to charge the proximity sensor to a predetermined voltage level, and compares the charge time to predetermined setpoints. The charge time will be greater than the setpoints when a user is grasping the iron handle due to the effective capacitance created by the conductive sheet, the iron handle, and the user'"'"'s hand. To determine the position of the iron, the microprocessor detects whether the orientation sensor circuit is open or closed.

Claims

1. An electric iron, comprising:

(a) a handle with an inner surface for allowing a user of said iron to grasp said iron;

(b) a user proximity circuit for detecting whether said user is conformingly grasping said handle of said iron, said user proximity circuit comprising;

(i) a proximity sensor comprising a pliable conductive sheet disposed within said handle of said iron, said conductive sheet being sufficiently pliable so as to substantially conform to said inner surface of said handle, wherein said pliable conductive sheet functions as a first plate of a capacitor and a hand of said user functions as a second plate of said capacitor such that an increase capacitance is created when said user is grasping said handle of said iron, and wherein said pliable conductive sheet is disposed to conform to said inner surface of said handle of said iron in such a manner that said user'"'"'s hand does not directly contact said conductive sheet when said user is grasping said handle of said iron;

(ii) a detection circuit coupled to said proximity sensor operative to detect said increased capacitance of said proximity sensor when said user is conformingly grasping said handle of said iron;

(c) a switching circuit controlled by said user proximity circuit operative to automatically connect and disconnect said iron to and from a source of electrical power based upon whether said user is conformingly grasping said handle of said iron.

2. The electric iron of claim 1 wherein said pliable conductive sheet substantially conforms to a surface shape of said handle.

3. The electric iron of claim 2 wherein said detection circuit and said switching circuit are incorporated within a microcontroller.

4. The electric iron of claim 1 wherein said detection circuit and said switching circuit are incorporated within a microcontroller.

5. The electric iron according to claim 1, wherein said detection circuit charges said pliable conductive sheet, detects when said pliable conductive sheet disposed within said handle has reached a predetermined voltage level, determines the amount of time required to charge said pliable conductive sheet disposed within said handle to said predetermined voltage level, and compares said amount of time to predetermined setpoints, and whereby said amount of time is greater than said setpoints when said user is conformingly grasping said handle of said iron due to the effective capacitance created by said pliable conductive sheet conforming to the surface of said handle, said handle, and said user'"'"'s hand.

6. The electric iron according to claim 1, further including an orientation circuit having an orientation sensor and a second detection circuit for detecting whether said iron is in an in-use position or a non-use position.

29. The method of controlling electrical power to an electric iron of claim 5 wherein said pliable conductive sheet substantially conforms to a surface shape of said handle.

7. An electric iron having a handle with an inner surface and a circuit for detecting whether a user is conformingly grasping said handle and automatically connecting and disconnecting said iron to and from a source of electrical power based upon such detection, said circuit consisting essentially of:

(a) a proximity sensor comprising a pliable conductive sheet disposed within said handle of said iron, said conductive sheet being sufficiently pliable so as to substantially conform to said inner surface of said handle, wherein said conductive sheet functions as a first plate of a capacitor and a hand of said user functions as a second plate of said capacitor such that an increased capacitance is created when said user is conformingly grasping said handle of said iron, and wherein said pliable conductive sheet is disposed to conform with said inner surface of said handle of said iron in such a manner that said user'"'"'s hand does not directly contact said conductive sheet when said user is conformingly grasping said handle of said iron; and

(b) a microcontroller coupled to said proximity sensor operative to;

(i) detect whether said user is conformingly grasping said handle of said iron by detecting said increased capacitance of said proximity sensor;

(ii) automatically connect and disconnect said iron to and from a source of electrical power based upon whether said user is conformingly grasping said handle of said iron.

8. The electric iron of claim 7 wherein said pliable conductive sheet substantially conforms to surface shape of said handle.

9. An electric iron, comprising:

(a) a handle with an inner surface for allowing a user of said iron to grasp said iron;

(b) a user proximity circuit for detecting whether said user is conformingly grasping said handle of said iron, said user proximity circuit comprising;

(i) a proximity sensor comprising a pliable conductive sheet disposed within said handle of said iron, said conductive sheet being sufficiently pliable so as to substantially conform to said inner surface of said handle, wherein said pliable conductive sheet functions as a first plate of a capacitor and a hand of said user functions as a second plate of said capacitor such that an increased capacitance is created when said user is conformingly grasping said handle of said iron, and wherein said pliable conductive sheet functions as a first plate of a capacitor and a hand of said user functions as a second plate of said capacitor such that an increased capacitance is created when said user is grasping said handle of said iron, and wherein said pliable conductive sheet is disposed to conform with said inner surface of said handle of said iron in such a manner that said user'"'"'s hand does not directly contact said conductive sheet when said user is grasping said handle of said iron;

(ii) a detection circuit coupled to said proximity sensor operative to detect said increased capacitance of said proximity sensor when said user is conformingly grasping said handle of said iron;

(c) an orientation circuit having an orientation sensor and a second detection circuit for detecting whether said iron is in an in-use position or a non-use position; and

(d) a switching circuit controlled by said user proximity circuit and said orientation circuit operative to automatically connect and disconnect said iron to and from a source of electrical power based upon whether said user is conformingly grasping said handle of said iron and whether said iron is in said in-use position or said non-use position.

10. The electric iron of claim 9 wherein said pliable conductive sheet substantially conforms to a surface shape of said handle.

11. The electric iron of claim 10 wherein said detection circuit, said second detection circuit, and said switching circuit are incorporated within a microcontroller.

12. The electric iron of claim 9 wherein said detection circuit, said second detection circuit, and said switching circuit are incorporated within a microcontroller.

13. The electric iron according to claim 9, wherein said detection circuit charges said pliable conductive sheet, detects when said pliable conductive sheet disposed within said handle has reached a predetermined voltage level, determines the amount of time required to charge said pliable conductive sheet disposed within said handle to said predetermined voltage level, and compares said amount of time to predetermined setpoints, and whereby said amount of time is greater than said setpoints when said user is conformingly grasping said handle of said iron due to the effective capacitance created by said pliable conductive sheet conforming to the surface of said handle, said handle, and said user'"'"'s hand.

14. An electric iron having a handle with an inner surface and a circuit for detecting whether a user is conformingly grasping said handle, detecting whether said iron is in an in-use position or non-use position, and automatically connecting and disconnecting said iron to and from a source of electrical power based thereon, said circuit consisting essentially of:

(a) a proximity sensor comprising a pliable conductive sheet disposed within said handle of said iron, said conductive sheet being sufficiently pliable so as to substantially conform to said inner surface of said handles wherein said pliable conductive sheet functions as a first plate of a capacitor and a hand of said user functions as a second plate of said capacitor such that an increased capacitance is created when said user is conforming grasping said handle of said iron, and wherein said pliable conductive sheet is disposed to conform with said inner surface of said handle of said iron in such a manner that said user'"'"'s hand does not directly contact said pliable conductive sheet when said user is conformingly grasping said handle of said iron;

(b) an orientation sensor; and

(c) a microcontroller coupled to said proximity sensor and said orientation sensor operative to;

(i) detect whether said user is conformingly grasping said handle of said iron by detecting said increased capacitance of said proximity sensor;

(ii) detect whether said iron is in an in-use position or a non-use position;

(iii) automatically connect and disconnect said iron to and from a source of electrical power based upon whether said user is conformingly grasping said handle of said iron and whether said iron is in said in-use position or said non-use position.

15. The electric iron of claim 14, wherein said pliable conductive sheet substantially conforms to a surface shape of said handle.

16. An electric iron, comprising:

(a) a handle with an inner surface for allowing a user of said iron to grasp said iron;

(b) a user proximity circuit for detecting whether said user is conformingly grasping said handle of said iron, said user proximity circuit comprising;

(i) a proximity sensor comprising a pliable conductive sheet disposed within said handle of said iron, wherein said pliable conductive sheet functions as a first plate of a capacitor and a hand of said user functions as a second plate of said capacitor such that an increased capacitance is created when said user is conformingly grasping said handle of said iron, and wherein said conductive sheet is disposed to conform with said inner surface of said handle of said iron is such a manner that said user'"'"'s hand does not directly contact said pliable conductive sheet when said user is conformingly grasping said handle of said iron;

(ii) means for detecting said increased capacitance of said proximity sensor; and

(c) means for automatically connecting and disconnecting said iron to and from a source of electrical power based upon whether said user is conformingly grasping said handle of said iron.

17. The electric iron of claim 16 wherein said pliable conductive sheet substantially conforms to a surface shape of said handle.

18. An electric iron, comprising:

(a) a handle with an inner surface for allowing a user of said iron to grasp said iron;

(b) a user proximity circuit for detecting whether said user is conformingly grasping said handle of said iron, said user proximity circuit comprising;

(i) a proximity sensor comprising a pliable conductive sheet disposed within said handle of said iron, said conductive sheet being sufficiently pliable so as to substantially conform to said inner surface of said handle, wherein said pliable conductive sheet functions as a first plate of a capacitor and a hand of said user functions as a second plate of said capacitor such that an increased capacitance is created when said user is conformingly grasping said handle of said iron, and wherein said pliable conductive sheet is disposed to conform with said inner surface of said handle of said iron in such a manner that said user'"'"'s hand does not directly contact said pliable conductive sheet when said user is grasping said handle of said iron;

(ii) means for detecting said increased capacitance of said proximity sensor;

(c) an orientation circuit having an orientation sensor and means for detecting whether said iron is in an in-use position or a non-use position; and

(d) means for automatically connecting and disconnecting said iron to and from a source of electrical power based upon whether said user is conformingly grasping said handle of said iron and whether said iron is in said in-use position or said non-use position.

19. The electric iron of claim 18 wherein said pliable conductive sheet substantially conforms to a surface shape of said handle.

20. The electric iron according to claim 18, wherein said means for detecting said increased capacitance of said proximity sensor includes means for charging said pliable conductive sheet, means for detecting when said pliable conductive sheet disposed within said handle has reached a predetermined voltage level, means for determining the amount of time required to charge said pliable conductive sheet disposed within said handle to said predetermined voltage level, and means for comparing said amount of time to predetermined setpoints, and whereby said amount of time is greater than said setpoints when said user is conformingly grasping said handle of said iron due to the effective capacitance created by said pliable conductive sheet conforming to the surface of said handle, said handle, and said user'"'"'s hand.

21. A method of detecting whether a user is conformingly grasping a handle of an electric iron, said handle having an inner surface, said method comprising the steps of:

(a) charging a pliable conductive plate said conductive plate being sufficiently pliable so as to substantially conform to said inner surface of said handle, said plate disposed to conform with said inner surface of said handle;

(b) detecting when said pliable conductive plate disposed within said handle has reached a predetermined voltage level;

(c) determining the amount of time required to charge said pliable conductive plate disposed within said handle to said predetermined voltage level; and

(d) comparing said amount of time to predetermined setpoints, wherein said amount of time is greater than said setpoints when said user is conformingly grasping said handle of said iron due to the effective capacitance created by said pliable conductive plate, said handle, and said user'"'"'s hand.

22. The method of detecting whether a user is conformingly grasping a handle of an electric iron of claim 21 wherein said steps are performed by a microprocessor.

23. The method of detecting whether a user is conformingly grasping a handle of an electric iron of claim 22 wherein said predetermined setpoints are stored in a permanent memory of said microprocessor.

24. The method of detecting whether a user is conformingly grasping a handle of an electric iron of claim 21 wherein said pliable conductive sheet substantially conforms to a surface shape of said handle.

25. A method of controlling electrical power to an electric iron, comprising the steps of:

(a) detecting whether a user is conformingly grasping a handle of said iron, said handle having an inner surface, by determining the effective capacitance of a pliable conductive sheets, said conductive sheet being sufficiently pliable so as to substantially conform to said inner surface of said handles, said conductive sheet disposed to conform with said inner surface of said handle of said iron;

(b) detecting whether said iron is in an in-use position or non-use position; and

(c) automatically connecting said iron to said source of electrical power when said user is conformingly grasping said handle of said iron and said iron is in an in-use position, automatically disconnecting said iron from said source of electrical power when said user is not grasping said handle of said iron and said iron is in an in-use position, and automatically disconnecting said iron from said source of electrical power after a predetermined amount of time when said iron is in a non-use position.

26. The method of controlling electrical power to an electric iron of claim 25 wherein said steps are performed by a microprocessor.

27. The method of controlling electrical power to an electric iron of claim 26 wherein said step of detecting whether a user is conformingly grasping said handle of said iron comprises the steps of:

(a) charging said pliable conductive sheet disposed to conform with said inner surface of said handle;

(b) detecting when said pliable conductive sheet disposed to conform with said inner surface of said handle has reached a predetermined voltage level;

(c) determining the amount of time required to charge said pliable conductive sheet disposed to conform with said inner surface of said handle to said predetermined voltage level; and

(d) comparing said amount of time to predetermined setpoints, wherein said amount of time is greater than said setpoints when said user is conforminly grasping said handle of said iron due to the effective capacitance created by said pliable conductive sheet, said handle, and said user'"'"'s hand.

28. The method of controlling electrical power to an electric iron of claim 27 wherein said predetermined setpoints are stored in a permanent memory of said microprocessor.