Distance measurement with capacitive sensor

Details Distance measurement with capacitive sensor Distance measurement with capacitive sensor

2008-10-30

2011-12-13

Colon, Eduardo (Department: 2837)

Electricity: measuring and testing

Impedance, admittance or other quantities representative of...

Lumped type parameters

C324S671000, C318S652000, C318S466000

Reexamination Certificate

active

08076948

ABSTRACT:
Circuits and methods to read out capacitive sensors for distance measurement used by a position control system having a high accuracy and low noise have been disclosed. The ratio or difference of the capacitances of two sensor capacitors is used to determine the distance of an object from a target position. A sense amplifier is using auto-zero methods to achieve a long term stability. A sample-and-hold circuit using double correlated sampling methods minimizes noise. Low cost capacitors can be used with the sample-and-hold circuit because not the absolute value of capacitances but only the ratio of capacitances are relevant. A high resolution is ensured also by significant over-sampling of the control loop.

REFERENCES:
patent: 5910781 (1999-06-01), Kawamoto et al.
patent: 6356085 (2002-03-01), Ryat et al.
patent: 6366099 (2002-04-01), Reddi
patent: 6486681 (2002-11-01), Weber et al.
patent: 6720777 (2004-04-01), Wang
patent: 6731121 (2004-05-01), Hsu et al.
patent: 6737648 (2004-05-01), Fedder et al.
patent: 6949937 (2005-09-01), Knoedgen
patent: 7256590 (2007-08-01), Kitaoka
patent: 7956621 (2011-06-01), Hollocher et al.
patent: 2005/0088184 (2005-04-01), Burdick et al.
patent: 2008/0037155 (2008-02-01), Hirano et al.
patent: 2008/0069413 (2008-03-01), Riedijk et al.
patent: 2008/0258044 (2008-10-01), Schrey et al.
patent: 1 548 409 (2005-06-01), None
patent: 08392011.6-1524 (2009-02-01), None
patent: WO 01/31351 (2001-05-01), None
“Correlated Double Sampling in Capacitive Position Sensing Circuits for Micromachined Applications,” by Wongkomet et al., 1998 IEEE, FP1-13.1 , pp. 723-726, 0-7803-5146-0/98.

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