Patents by Inventor Kee Eng Soo

Kee Eng Soo has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Circuit to prevent acoustic feedback for a cellular speakerphone
    Patent number: 7027604
    Abstract: This invention includes a circuit for the prevention of acoustic feedback between an electronic device and an audio accessory. In a preferred embodiment, the circuit prevents audio feedback between a cellular telephone and a speakerphone accessory. The circuit includes a current limiting device coupled serially in the receive (Rx) line. The current limiting device is actuated via a delay circuit coupled between the current limiting device and the transmit (Tx) line. When a bias current is presented to the Tx line, the bias propagates through the delay circuit, thereby actuating the current limiting device a predetermined time after the presentation of the bias. The circuit keeps the Rx line open long enough for the phone to deactivate its internal microphone.
    Type: Grant
    Filed: September 24, 2001
    Date of Patent: April 11, 2006
    Assignee: Motorola, Inc.
    Inventors: Kee Eng Soo, Ashok Ramakant Patil, Michael D. Geren, Macwien Krishnamurthi Annamalai
  • Circuit to prevent acoustic feedback for a cellular speakerphone
    Publication number: 20030059062
    Abstract: This invention includes a circuit for the prevention of acoustic feedback between an electronic device and an audio accessory. In a preferred embodiment, the circuit prevents audio feedback between a cellular telephone and a speakerphone accessory. The circuit includes a current limiting device coupled serially in the receive (Rx) line. The current limiting device is actuated via a delay circuit coupled between the current limiting device and the transmit (Tx) line. When a bias current is presented to the Tx line, the bias propagates through the delay circuit, thereby actuating the current limiting device a predetermined time after the presentation of the bias. The circuit keeps the Rx line open long enough for the phone to deactivate its internal microphone.
    Type: Application
    Filed: September 24, 2001
    Publication date: March 27, 2003
    Inventors: Kee Eng Soo, Ashok Ramakant Patil, Michael D. Geren, Macwien Krishnamurthi Annamalai