PHASE MODULATION SIGNAL GENERATION CIRCUIT AND DISPLACEMENT DETECTION DEVICE USING THE SAME
PROBLEM TO BE SOLVED: To provide a phase modulation signal generation circuit (displacement detection device) in which the effect of a drift or arithmetic error arising from an analog multiplication process is avoided and circuit configuration is simplified.SOLUTION: A phase modulation signal genera...
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Main Authors | , , |
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Format | Patent |
Language | English Japanese |
Published |
25.08.2016
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Subjects | |
Online Access | Get full text |
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Summary: | PROBLEM TO BE SOLVED: To provide a phase modulation signal generation circuit (displacement detection device) in which the effect of a drift or arithmetic error arising from an analog multiplication process is avoided and circuit configuration is simplified.SOLUTION: A phase modulation signal generation circuit 3 has: a modulation signal generation circuit 31 for generating a square wave modulation signal RsinT; a signal generation circuit 32 for shifting the phase of the modulation signal RsinT by 90° and generating gain control signals GSTL, GCTL; a series circuit of an analog switch 33 and a differential amplifier 34 for generating a balanced modulation signal Bc(T); a series circuit of an analog switch 35 and a differential amplifier 36 for generating a balanced modulation signal Bs(T); an addition circuit 37 for adding two balanced modulation signals Bc(T) and Bs(T), preferably, for current addition; and a low-pass filter (LPF) 38 having a small amount of attenuation.SELECTED DRAWING: Figure 6
【課題】アナログ乗算処理に伴うドリフトや演算誤差の影響を避け、回路構成を簡単にした位相変調信号生成回路(変位量検出装置)を提供する。【解決手段】位相変調信号生成回路3は、矩形波の変調信号RsinTを生成する変調信号生成回路31、変調信号RsinTを90°移相し利得制御信号GSTL、GCTLを生成する信号発生回路32、平衡変調信号Bc(T)を生成するアナログスイッチ33と差動増幅アンプ34との直列回路、平衡変調信号Bs(T)を生成するアナログスイッチ35と差動増幅アンプ36との直列回路、2つの平衡変調信号Bc(T)とBs(T)を、好ましくは、電流加算する加算回路37、および、減衰量の小さなローパスフィルタ(LPF)38を有する。【選択図】図6 |
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Bibliography: | Application Number: JP20150031493 |