US 7,545,153 B2
Capacitance detecting proximity sensor
Hiroshi Abe, Kanagawa (Japan)
Assigned to ACT · LSI Inc., Atsugi-shi (Japan)
Appl. No. 10/540,454
PCT Filed Dec. 25, 2003, PCT No. PCT/JP03/16805
§ 371(c)(1), (2), (4) Date May 24, 2006,
PCT Pub. No. WO2004/059343, PCT Pub. Date Jul. 15, 2004.
Claims priority of application No. 2002-373729 (JP), filed on Dec. 25, 2002.
Prior Publication US 2006/0250142 A1, Nov. 09, 2006
Int. Cl. G01R 27/26 (2006.01)
U.S. Cl. 324—663  [324/658] 4 Claims
OG exemplary drawing
 
1. A capacitance detecting proximity sensor that electrostatically detects when a detection subject has come into proximity within a difference threshold, comprising:
a sensor structure housing a first detection electrode and a second detection electrode that are mutually electrically independent, both detecting surfaces of the first detection electrode and the second detection electrode being disposed opposing the detection subject that is approaching, the environment of the first detection electrode and the second detection electrode in the sensor structure being differentiated and configured so that when the detection subject is present in the vicinity of the difference threshold, the electrostatic environmental condition between the detection subject and the first detection electrode and the electrostatic environmental condition between the same detection subject and the second detection electrode being different; and
a sensor circuit for detecting and outputting the difference between a capacitance to ground formed by the first detection electrode and a capacitance to ground formed by the second detection electrode,
wherein the first detection electrode is divided into a plurality of first detection electrode divisions and the second detection electrode is divided into a plurality of second electrode divisions, and
a shield electrode disposed to individually surround each first detection electrode division and each second detection electrode division so as to electrostatically shield each first detection electrode division and each second detection electrode division in at least one non-detection direction.