Invention Grant
- Patent Title: Method and apparatus for detecting a touch on a device
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Application No.: US14858149Application Date: 2015-09-18
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Publication No.: US09639225B2Publication Date: 2017-05-02
- Inventor: Bing Qin Lim , Murali Kuyimbil , Wai Mun Lee , Lee Sun Ooi , Wooi Ping Teoh
- Applicant: MOTOROLA SOLUTIONS, INC
- Applicant Address: US IL Chicago
- Assignee: MOTOROLA SOLUTIONS, INC.
- Current Assignee: MOTOROLA SOLUTIONS, INC.
- Current Assignee Address: US IL Chicago
- Main IPC: G06F3/045
- IPC: G06F3/045 ; G06F3/044 ; H03L7/099

Abstract:
A method and circuitry for detecting a touch on a device is provided herein. Touch-sensing circuitry comprises two antennas coupled to two voltage-controlled oscillators (VCOs). A phase locked loop (PLL) is provided coupled to the VCOs. The PLL compares a VCO output with a frequency source (temperature controlled crystal oscillator (TCXO)), and outputs a tuning voltage (steering voltage) for the VCO that is based on the difference between the VCO frequency and the TCXO frequency. The steering voltages for each VCO are compared, and a decision is made as to whether or not a touch has been made to the antennas. If the antennas have been touched, a location of the touch is determined based on a difference in the steering voltages of the two VCOs.
Public/Granted literature
- US20170083126A1 METHOD AND APPARATUS FOR DETECTING A TOUCH ON A DEVICE Public/Granted day:2017-03-23
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