| 摘要 |
PURPOSE:To make high resolution available without necessity of mechanical fine division of an electrode itself, by arranging a signal receiving electrode with equi-distance pitches of integral fraction of wave length pitch of its opposedly located signal transmitting electrode. CONSTITUTION:No.1 scale 10 and No.2 scale 20 make relative displacements in the vicinity of each other. Capacitive coupling is established between the No.1 signal transmitting electrode 12 installed on the scale 10 and the No.2 signal receiving electrode 22 installed on the scale 20. The electrode 12 forms a group of 8 electrodes in order that, for example, 8 AC signals are received respectively. Consequently, the length of this one group constitutes the signal transmitting wave length pitch Wt1 and the electrode 22 is composed of a plurality of electrodes of the equal distance pitch obtained by division of the pitch Wt1 by the specified integer, for example 3. By this arrangement. Position detection can be available by a number of signal transmitting electrodes in the electrode group 22 of a signal receiving electrode pitch Pr2, namely 1/8 scale accuracy.
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