MICROPHONE PROXIMITY DETECTION

• US 20130295906A1
• Filed: 07/08/2013
• Published: 11/07/2013
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Chen, Shaohai, Dinh, Richard Hung Minh, Lee, Jae, Seguin, Chad G., Pope, Benjamin J.
• Granted Patent: US 8,917,577 B2
• Time in Patent Office: Days
• US Class Current: 455/418
• CPC Class Codes: G01S 11/14 using ultrasonic, sonic, or infrasonic waves
• CPC Class Codes: H04M 1/03 Constructional features of telephone transmitters or receivers, e.g. telephone hand-sets
• CPC Class Codes: H04M 1/6008 in the transmitter circuit
• 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 2250/22 including a touch pad, a touch sensor or a touch detector
• CPC Class Codes: H04W 8/22 Processing or transfer of terminal data, e.g. status or physical capabilities

Abstract

A mobile communications device contains at least two microphones. One microphone is located away from the handset receiver and serves to pick up voice of a near end user of the device for transmission to the other party during a call. Another microphone is located near the handset receiver and serves to pick up acoustic output of the handset receiver (a far end signal). A signal processor measures the frequency response of the receiver. The signal processor performs spectral analysis of the receiver frequency response to determine whether or not the device is being held at the ear of the user. On that basis, the device automatically changes its operating mode, e.g., turns on or off a touch sensitive display screen during the call. Other embodiments are also described.

Claims

1. A method for operating a mobile telephony device, comprising:

monitoring during a call a frequency response of a handset receiver of the mobile device over a frequency band;

maintaining the mobile device in one operating mode, while the frequency response over the frequency band is on one side of a predetermined threshold value; and

switching the mobile device from said one operating mode to a different operating mode automatically, when the frequency response over the frequency band goes to another side of the predetermined threshold value.

2. The method of claim 1, wherein the frequency band is in the range of less than 1000 Hz.

3. The method of claim 2, wherein the frequency response is a ratio of H.sub.out/H.sub.in as a function of frequency, wherein H.sub.out corresponds to output from the handset receiver as detected by a microphone that is integrated with the handset receiver, and H.sub.u, corresponds to input to the handset receiver.

4. The method of claim 1, wherein in said one operating mode a touch screen of the device is activated to enable user input, and in some different operating mode the touch screen is inactive to disable user input.

5. A machine-implemented method comprising;

measuring acoustic output of a speakerphone speaker in a mobile device during a call;

determining a proximity of an object to the mobile device based on the measured acoustic output;

maintaining speakerphone mode of the mobile device during the call when the proximity indicates far; and

switching the mobile device from the speakerphone mode to handset mode automatically when the proximity indicates near.

6. The method of claim 5, wherein user input through a touch sensitive display screen of the device is suppressed in the handset mode and enabled in the speaker phone mode.

7. The method of claim 5, wherein the proximity indicates near when the mobile device is situated in an at-ear position and far when the mobile device is situated in an open position.

8. The method of claim 5, further comprising:

reading a proximity sensor, wherein said determining the proximity is further based on said reading.

9. The method of claim 5, wherein said switching the mobile device comprises turning off a touch sensitive display screen of the device in the handset mode, and turning on the touch sensitive display screen of the device in the speakerphone mode.