Ultrasonic proximity detector for a telephone device

• US 20020028699A1
• Filed: 09/06/2001
• Published: 03/07/2002
• Est. Priority Date: 09/07/2000
• Status: Active Grant

• Current Assignee: Mitel Networks Corporation
• Original Assignee: Mitel Corporation (Microchip Technology Incorporated)
• Inventors: Moquin, Philippe, Dedieu, Stephane
• Granted Patent: US 7,010,098 B2
• Time in Patent Office: Days
• US Class Current: 455/569.1
• CPC Class Codes: H04M 1/60 including speech amplifiers
• CPC Class Codes: H04M 1/6033 for providing handsfree use or a loudspeaker mode in telephone sets arrangements for preventing acoustic echo H04M9/08
• CPC Class Codes: H04M 1/605 involving control of the receiver volume to provide a dual operational mode at close or far distance from the user
• CPC Class Codes: H04M 2250/12 including a sensor for measuring a physical value, e.g. temperature or motion

Abstract

An ultrasonic proximity detector for a telephone device to detect the proximity of an object thereto includes an ultrasound signal generator generating ultrasound that is broadcast by a speaker of the telephone device. Processing circuitry is coupled to a microphone of the telephone device. The processing circuitry processes broadcast ultrasound that is picked up by the microphone to detect the proximity of an object to the telephone device.

Claims

1. An ultrasonic proximity detector for a telephone device to detect the proximity of an object thereto, said ultrasonic proximity detector comprising:

an ultrasound generator generating ultrasound that is broadcast by a speaker of said telephone device; and

processing circuitry coupled to a microphone of said telephone device, said processing circuitry processing broadcast ultrasound that is picked up by said microphone to detect the proximity of an object to said telephone device.

2. An ultrasonic proximity detector according to claim 1 wherein said telephone device includes a handset including said microphone, said handset being coupled to a telephone set and wherein said processing circuitry processes said picked up ultrasound to detect the proximity of said handset to said telephone set.

3. An ultrasonic proximity detector according to claim 2 wherein said telephone set includes a cradle to accommodate said handset, said processing circuitry generating hookswitch signals when said handset is proximate to said cradle.

4. An ultrasonic proximity detector according to claim 3 further including an ultrasound waveguide extending from adjacent said speaker to a portion of the cradle accommodating the handset microphone.

5. An ultrasonic proximity detector according to claim 2 wherein said processing circuitry includes a filter to isolate the picked up ultrasound from other signals picked up by said microphone and a threshold detector coupled to said filter to determine ultrasound levels above a threshold level.

6. An ultrasonic proximity detector according to claim 5 wherein said threshold detector outputs hookswitch signals when said handset is within a threshold distance from said telephone set.

8. An ultrasonic proximity detector according to claim 1 wherein said telephone device is a mobile telephone and wherein said processing circuitry processes said picked up ultrasound to detect the proximity of a portion of a user to said mobile telephone.

9. An ultrasonic proximity detector according to claim 8 wherein said portion is a user'"'"'s hand.

10. An ultrasonic proximity detector according to claim 9 wherein said processing circuitry includes a filter to isolate said picked up ultrasound from other signals picked up by said microphone and a threshold detector coupled to said filter to determine ultrasound levels above a threshold level.

11. An ultrasonic proximity detector according to claim 10 wherein said threshold detector outputs transition signals when the user'"'"'s hand is proximate to said mobile telephone to switch the mode of operation of said mobile telephone.

12. An ultrasonic proximity detector according to claim 9 wherein said processing circuitry includes a filter to isolate said picked up ultrasound from other signals picked up by said microphone and scaling circuitry coupled to said filter, said scaling circuitry scaling the level of voice signals applied to said speaker for broadcast with said ultrasound.

13. An ultrasonic proximity detector according to claim 12 wherein said scaling circuitry includes an amplifier receiving the output of said filter and a variable resistor responsive to said amplifier.

14. An ultrasonic proximity detector according to claim 1 wherein said telephone device is a full-duplex speaker telephone having a hands-free microphone and wherein said processing circuitry processes said picked up ultrasound to detect the proximity of an object that alters the coupling between said hands-free microphone and said speaker.

15. An ultrasonic proximity detector according to claim 14 wherein said processing circuitry includes a filter to isolate the picked up ultrasound from other signals picked up by said microphone, a threshold detector to detect when the level of the ultrasound is above a threshold level, and a digital signal processor executing a fall-duplex algorithm, said digital signal processor being responsive to said threshold detector and acting on signals picked up by said microphone.

16. An ultrasonic proximity detector according to claim 15 wherein the signals picked up by said microphone are digitized prior to being acted on by said digital signal processor.

17. An ultrasonic proximity detector is defined in claim 1 wherein said telephone device is a telephone headset and wherein said processing circuitry processes said picked up ultrasound to detect if said headset is being worn by a user.

19. A telephone device according to claim 18 wherein said processing circuitry generates hookswitch signals when said handset is proximate to said cradle.

20. A telephone device according to claim 19 further including an ultrasound waveguide extending from adjacent said loudspeaker and microphone assembly to a portion of the cradle accommodating the handset microphone.

21. A telephone device according to claim 20 wherein said processing circuitry includes a filter to isolate the picked up ultrasound from other signals picked up by said loudspeaker and microphone assembly and a threshold detector coupled to said filter to determine ultrasound levels above a threshold level.

22. A telephone device according to claim 21 wherein said threshold detector outputs hookswitch signals when said handset is within a threshold distance from said telephone set.

23. A telephone device according to claim 22 wherein said processing circuitry further includes a preamplifier.

25. A mobile telephone according to claim 24 wherein said portion is a user'"'"'s hand.

26. A mobile telephone according to claim 25 wherein said processing circuitry includes a filter to isolate said picked up ultrasound from other signals picked up by said microphone and a threshold detector coupled to said filter to determine ultrasound levels above a threshold level.

27. A mobile telephone according to claim 26 wherein said threshold detector outputs transition signals when the user'"'"'s hand is proximate to said mobile telephone to switch the mode of operation of said mobile telephone.

28. A mobile telephone according to claim 25 wherein said processing circuitry includes a filter to isolate said picked up ultrasound from other signals picked up by said microphone and scaling circuitry coupled to said filter, said scaling circuitry scaling the level of voice signals applied to said speaker for broadcast with said ultrasound.

29. A mobile telephone according to claim 28 wherein said scaling circuitry includes an amplifier receiving the output of said filter and a variable resistor responsive to said amplifier.

7. An ultrasonic proximity detector according to claim 7 wherein said processing circuitry further includes a preamplifier.

18. A telephone device comprising:

a telephone set;

a handset coupled to said telephone set;

a cradle on said telephone set to accommodate said handet;

a keypad on said telephone set;

a loudspeaker and microphone assembly accommodated by said telephone set;

circuitry within said telephone set to handle incoming and outgoing telephone calls; and

an ultrasonic proximity detector accommodated by said telephone set, said ultrasonic proximity detector including;

an ultrasound generator generating ultrasound that is broadcast by said loudspeaker and microphone assembly; and

processing circuitry coupled to said loudspeaker and microphone assembly, said processing circuitry processing broadcast ultrasound that is picked up by said loudspeaker and microphone assembly to detect the proximity of said handset to said telephone set.

24. A mobile telephone comprising:

a telephone set;

a keypad on said telephone set;

a loudspeaker accommodated by said telephone set;

a microphone accommodated by said telephone set;

circuitry within said telephone set to handle incoming and outgoing telephone calls; and

an ultrasonic proximity detector accommodated by said telephone set, said ultrasonic proximity detector including;

an ultrasound generator generating ultrasound that is broadcast by said loudspeaker; and

processing circuitry coupled to said microphone, said processing circuitry processing broadcast ultrasound that is picked up by said microphone to detect the proximity of a portion of a user to said mobile telephone.

30. A full-duplex telephone device comprising:

a telephone set;

a keypad on said telephone set;

a loudspeaker accommodated by said telephone set;

a hands-free microphone accommodated by said telephone set;

circuitry within said telephone set to handle incoming and outgoing telephone calls; and

an ultrasonic proximity detector accommodated by said telephone set, said ultrasonic proximity detector including;

an ultrasound generator generating ultrasound that is broadcast by said loudspeaker; and

processing circuitry coupled to said hands-free microphone, said processing circuitry processing broadcast ultrasound that is picked up by said hands-free microphone to detect the proximity of an object that alters the 25 coupling between said hands-free microphone and said loudspeaker.

31. A full-duplex telephone device according to claim 30 wherein said processing circuitry includes a filter to isolate the picked up ultrasound from other signals picked up by said hands-free microphone, a threshold detector to detect when the level of the ultrasound is above a threshold level, and a digital signal processor executing a full-duplex algorithm, said digital signal processor being responsive to said threshold detector and acting on signals picked up by said hands-free microphone.

32. A full-duplex telephone device according to claim 31 wherein the signals picked up by said hands-free microphone are digitized prior to being acted on by said digital signal processor.