Capacitive touchpad having dual traces coupled with uneven spaced interlaced sensors
AssigneeElan Microelectronics Corporation
InventorsChao-Hui Hsu, Yen-Chang Chiu
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Abstract
A capacitive touchpad comprises two traces with a plurality of first and second sensors coupled thereto respectively, and the first and second sensors are arranged interlaced and uneven spaced to each other. By detecting the capacitance variances produced by the sensors from the traces, phase leading or lagging Z-axis signals are generated to determine the moving direction of a finger sliding on the capacitive touchpad.
Claims13
A capacitive touchpad comprising:
- a first trace and a second trace;
- and
- a plurality of first and second sensors, interlaced and uneven spaced therebetween, coupled to the first and second axes respectively.
A detection method for a capacitive touchpad including a first trace and a second trace with a plurality of first and second sensors coupled thereto respectively, the first and second sensors being arranged interlaced and uneven spaced to each other, the method comprising the steps of:
- detecting the capacitance variance of the sensors to produce a first trace signal and a second trace signal;
- and
- determining a moving direction of an object sliding on the capacitive touchpad based on a phase derived from the first and second trace signals.
The method of clime 4, further comprising determining the phase based on shifting the reference of the voltage level corresponding to the capacitance variance.
A detection method for a capacitive touchpad including a first trace, a second trace and a third trace with a plurality of first, second and third sensors coupled thereto respectively, the first and second sensors being arranged interlaced and uneven spaced to each other, the third sensors being arranged interlaced between the first and second sensors, the method comprising the steps of:
- detecting the capacitance variance of the sensors to produce a first trace signal, a second trace signal and a third trace signal;
- and
- determining a moving direction of an object sliding on the capacitive touchpad based on a phase derived from the first and second trace signals;
- wherein the third trace signal is used as a reference for the first and second trace signals.
A detection method for a capacitive touchpad including a first trace, a second trace, a third trace and a fourth trace with a plurality of first, second, third and fourth sensors coupled thereto respectively, the first and second sensors being arranged interlaced and uneven spaced to each other, the third and fourth sensors being arranged interlaced between the first and second sensors, the method comprising the steps of:
- detecting the capacitance variance of the sensors to produce a first trace signal, a second trace signal, a third trace signal and a fourth trace signal;
- and
- determining a moving direction of an object sliding on the capacitive touchpad based on a phase derived from the first and second trace signals;
- wherein the third trace signal is used as a first reference for the first and second trace signals, and the fourth trace signal is used as a second reference for determining the capacitance variance.
Dependencies are inferred from the claim text.