Radiotelephone proximity detector

• US 5,943,628 A
• Filed: 10/22/1997
• Issued: 08/24/1999
• Est. Priority Date: 10/23/1996
• Status: Expired due to Term

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Isotalo, Mika, Haavisto, Jouko, Barrett, Steven
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): Ferguson, Keith
• Application Number:
  US08/955,508
• Time in Patent Office: 671 Days
• Field of Search: 455/574, 455/575, 455/462, 455/456, 455/457, 455/88, 340/825.45, 340/573, 340/539, 340/568, 340/571
• US Class Current: 455/574
• CPC Class Codes: A45F 2005/026 with a pin having an enlarged head detachably connected to a fastening device, e.g. to a pin receiving slot
• CPC Class Codes: A45F 2200/0516 Portable handheld communication devices, e.g. mobile phone, pager, beeper, PDA, smart phone
• CPC Class Codes: A45F 5/021 to the belt
• CPC Class Codes: G01S 13/04 Systems determining presence of a target based on relative movement of target G01S13/56
• CPC Class Codes: G01S 13/74 Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
• CPC Class Codes: G08B 21/023 Power management, e.g. system sleep and wake up provisions
• CPC Class Codes: G08B 21/0247 System arrangements wherein the alarm criteria uses signal strength
• CPC Class Codes: G08B 21/24 Reminder alarms, e.g. anti-loss alarms
• CPC Class Codes: H04B 1/3833 Hand-held transceivers
• CPC Class Codes: H04B 1/3838 Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use
• CPC Class Codes: H04M 1/05 specially adapted for use on head, throat or breast
• CPC Class Codes: H04M 1/6041 Portable telephones adapted for handsfree use
• CPC Class Codes: H04M 1/724 User interfaces specially adapted for cordless or mobile telephones
• CPC Class Codes: H04M 2250/12 including a sensor for measuring a physical value, e.g. temperature or motion
• CPC Class Codes: H04W 52/0251 using monitoring of local events, e.g. events related to user activity
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A radiotelephone proximity detector including a first proximity unit having a receiver and a second proximity unit having a transmitter, wherein the units can be coupled together and the coupling can be detected. One of the units is associated with a radiotelephone and the other with a user. When the units are coupled, they are responsive to the detection of their uncoupling, whereupon the transmitter of the second proximity unit transmits a proximity signal to the receiver of the first unit. The first proximity unit estimates the proximity of the radiotelephone and the user on the basis of the received proximity signal. Thus the two units operate together such that, when coupled, at least one of the units enters a standby mode, and when uncoupled, at least one of the units sends a proximity signal to the other unit.

Claims

1. A radiotelephone proximity detector, comprising:

a first proximity unit having a receiver and a second proximity unit having a transmitter, one of the units being associated with a radiotelephone and one of the units being associated with a user;

means for coupling said units together in a home position;

means for detecting when the units are coupled together in the home position and when the units become uncoupled from the home position, and for providing a first signal and a second signal respectively indicative thereof;

means, responsive to the second signal, for causing the transmitter to transmit a proximity signal to the receiver for indicating the proximity from the home position;

means, responsive to the proximity signal, for estimating the proximity of the radiotelephone and the user on the basis of the received proximity signal; and

means, responsive to the first signal, for causing at least one of the proximity units to enter a standby mode.

2. A detector as in claim 1, wherein the detecting means comprises a detecting element on the first proximity unit and a detecting element on the second proximity unit.

3. A detector as in claim 2, wherein the detecting means is responsive to contact between the detecting elements.

4. A detector as in claim 2, wherein the detecting means is responsive to a capacitive coupling between the detecting elements.

5. A detector as in claim 1, wherein the proximity unit associated with the user is adapted to be mounted in a belt clip assembly, which the user can wear.

6. A detector as in claim 1, wherein the transmitter has a reduced power mode in which it is deactivated.

7. A detector as claimed in claim 1 wherein the first proximity unit is associated with a radiotelephone and the second proximity unit is associated with a user.

8. A detector as claimed in claim 1 wherein the estimating means comprises means for estimating the proximity of the first and second proximity units by comparing the signal strength of the received proximity signal with a threshold.

9. A detector as claimed in claim 8 further comprising means, responsive to the received signal strength falling below the threshold, for sounding an alarm.

10. A detector as claimed in claim 1 wherein the estimating means is in the first proximity unit.

11. A detector as claimed in claim 1 wherein the estimating means is in the second proximity unit.

12. A detector as claimed in claim 1 wherein the the estimating means comprises means for estimating the proximity of the first and second proximity units by estimating the time taken for the proximity signal to travel between the first and second proximity units.

13. A detector as claimed in claim 12 wherein the first proximity unit comprises means for locating the unit within the casing of a radiotelephone and is powered by the battery of the radiotelephone.

14. A detector as claimed in claim 1 wherein the transmitter of the first proximity unit comprises means dedicated to the task of monitoring the proximity of the first and second proximity units.

15. A detector as claimed in claim 1 wherein the first proximity unit is associated with a user and the second proximity unit is associated with a radiotelephone.