Electricity: measuring and testing – Impedance – admittance or other quantities representative of... – Lumped type parameters
Reexamination Certificate
2006-06-03
2008-11-11
Nguyen, Vincent Q (Department: 2831)
Electricity: measuring and testing
Impedance, admittance or other quantities representative of...
Lumped type parameters
Reexamination Certificate
active
07449895
ABSTRACT:
Methods, systems and devices are described for detecting a measurable capacitance using charge transfer techniques. According to various embodiments, a charge transfer process is performed for two or more times. During the charge transfer process, a pre-determined voltage is applied to the measurable capacitance, and the measurable capacitance is then allowed to share charge with a filter capacitance through a passive impedance that remains coupled to both the measurable capacitance and to the filter capacitance throughout the charge transfer process. The value of the measurable capacitance can then be determined as a function of a representation of a charge on the filter capacitance and the number of times that the charge transfer process was performed. Such a detection scheme may be readily implemented using conventional components, and can be particularly useful in sensing the position of a finger, stylus or other object with respect to an input sensor.
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Ely David
Haines Julian
Hargreaves Kirk
Reynolds Joseph Kurth
Routley Paul
Ingrassia Fisher & Lorenz P.C.
Nguyen Vincent Q
Synaptics Incorporated
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