US 9,810,550 B2
Position detection device
Atsutoshi Goto, Tokyo (JP); Daisuke Goto, Tokyo (JP); Kazuya Sakamoto, Tokyo (JP); and Shuichi Tanaka, Kanagawa (JP)
Assigned to AMITEQ CO., LTD., Tokyo (JP)
Appl. No. 14/400,676
Filed by AMITEQ CO., LTD., Tokyo (JP)
PCT Filed May 13, 2013, PCT No. PCT/JP2013/063339
§ 371(c)(1), (2) Date Nov. 12, 2014,
PCT Pub. No. WO2013/172315, PCT Pub. Date Nov. 21, 2013.
Claims priority of application No. 2012-111065 (JP), filed on May 14, 2012.
Prior Publication US 2015/0130444 A1, May 14, 2015
Int. Cl. G01D 5/14 (2006.01); G01D 5/22 (2006.01)
CPC G01D 5/14 (2013.01) [G01D 5/2258 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A position detection device comprising:
a coil section including at least two pairs of coils to be excited by an AC signal, coils constituting each one of the pairs being disposed at predetermined intervals;
a magnetism-responsive member movable relative to said coil section, a relative position of the magnetism-responsive member in relation to the coil section varying in accordance with a position of a detection object, the magnetism-responsive member being constructed to vary impedance of each coil according to the relative position, impedance variations of two coils constituting each one of pairs presenting characteristics of mutually opposite phase characteristics; and
a circuitry that constructs, for each of the pairs, a serial connection circuit of coils in which the two coils constituting the pair are connected in series with each other, supplies the AC signal to the serial connection circuit of coils for each of the pairs, and takes out, for each of the pairs, a voltage-divided output voltage responsive to the impedance of the two coils in the pair from a connection point of the two coils in the serial connection circuit for the pair as a detection output signal for the pair,
wherein the detection output signal of a first pair of the at least two pairs of coils represents an amplitude characteristic of a plus sine phase to the position of the detection object; the detection output signal of a second pair of the at least two pairs of coils represents an amplitude characteristic of a minus sine phase to the position of the detection object; the detection output signal of a third pair of the at least two pairs of coils represents an amplitude characteristic of a plus cosine phase to the position of the detection object; and the detection output signal of a fourth pair of the at least two pairs of coils represents an amplitude characteristic of a minus cosine phase to the position of the detection object.