201000867 六、發明說明： 【發明所屬之技術領域】 本發明係關於用以檢測移動構件對固定構件之的行程 (stroke )量、在將停止位置作回授控制時該移動構件之 實際位置的位置檢測裝置及使用該位置檢測裝置之線性致 動器。 【先前技術】 以住’以該類位置檢測裝置而言，已知被揭示於曰本 特開平6-180203號公報、日本特開2006-337212等者。具體 而言，由以預定間距附加有光學或磁性指標（index )的 線性標度尺（linear scale )、及與該線性標度尺相對向配 置並且讀取前述指標的位置檢測感測器所構成，例如將前 述線性標度尺固定在線性致動器的固定構件，將前述位置 檢測感測器固定在移動構件’使位置檢測感測器對線性標 度尺作相對移動’藉此可掌握移動構件對前述固定構件的 移動量。 前述位置檢測感測器係具備有一對檢測頭，各檢測頭 在讀取前述線性標度尺的指標時，輸出以該指標的1間距 爲1周期的正弦波。此外，該等一對檢測頭係對指標的配 列間距的整數倍偏移1 / 4間距而作配置，具備有9 〇度之相 位差的正弦波A相及餘弦波B相由該等檢測頭被輸出。因此 ，藉由將A相及B相作比較，可掌握移動構件對固定構件的 移動方向，另外可以將指標的間距以複數分割後的精度來 -5- 201000867 掌握移動構件的移動量。 使用該線性標度尺的位置檢測裝置係主要在對移動構 件的位置或速度作回授控制的目的之下加以使用，但是在 實際上使用時，因位置檢測裝置之缺失爲原因，爲了避免 前述移動構件由預定的移動範圍、亦即有效行程範圍脫離 的問題，有別於前述位置檢測裝置，在該有效行程範圍的 兩端設置限制開關等外部開關來加以使用的情形有不少。 該外部開關係在前述移動構件由有效行程範圍脫離時 用以檢測該情形者，例如在線性致動器使用中，前述外部 開關的訊號由關斷（off)變化成導通（ΟΠ)時，以該訊號 變化爲觸發器（trigger )，可謀求線性致動器緊急停止等 措施。 若亦有該外部開關係藉由移動構件的接觸而使輸出訊 號作切換的機械式開關的情形，如日本特開2006-337212 之揭示，亦有由磁性體及用以檢測其之磁性感測器所構成 的情形。 另一方面，在日本特開平6-180203號公報所揭示的位 置檢測裝置中並未設置外部開關，其構成爲：將位置檢測 訊號的計數値和與有效行程範圍的兩端相對應的計數値作 比較，根據該比較結果，謀求線性致動器緊急停止等措施 [先前技術文獻] (專利文獻1)日本特開平6-180203號公報 201000867 (專利文獻2)日本特開2006-3 3 72 1 2號公報 【發明內容】 (發明所欲解決之課題） 但是，爲了檢測有效行程範圍，如前所述，與位置檢 測裝置另外個別地設置一對外部開關，必須多餘設置該外 部開關的配置空間或配線空間，對於需要位置檢測裝置之 線性致動器等機器的小型化會帶來阻礙。 此外，不使用外部開關而僅使用位置檢測訊號的計數 値來判斷有效行程範圍，若考慮到因某些要因而在位置檢 測訊號發生擾亂的情形時，很可能會發生無法正確辨識有 效行程範圍的兩端的情形。 (解決課題之手段） 本發明係鑑於如上所示之問題點而硏創者，其目的在 於提供一種無須使用外部開關，可確認移動構件是否存在 於有效行程範圍內’而有助於線性致動器小型化的位置檢 測裝置。 亦即’本發明之位置檢測裝置，其具備有：以預定間 距配列有指標的第一標度尺；與該第一標度尺相對向配置 而檢測該指標的第一檢測感測器；與前述第一標度尺相鄰 接配置’並且以與該第一標度尺爲相同間距配列有指標的 第二標度尺；及與該第二標度尺相對向配置而檢測該指標 的第二檢測感測器，在前述第一標度尺或第二標度尺中之 201000867 指標配列方向的兩端係設有前述第一檢測感測器及第二檢 測感測器的輸出訊號爲不同的區外辨識區域。 此外’使用該位置檢測裝置的線性致動器係具備有： 第一構件；可對該第一構件作相對並進運動的第二構件； 對前述第一構件推進第二構件的驅動手段；被設在前述第 一構件的第一標度尺；被裝載在前述第二構件的第一檢測 感測器；被設在前述第一構件，與前述第一標度尺相鄰接 配置的第二標度尺；被裝載在前述第二構件的第二檢測感 測器；及接收由前述第一檢測感測器及第二檢測感測器所 被輸出的檢測訊號，以控制前述驅動手段的驅動控制手段 ’在前述第一標度尺或第二標度尺中之指標配列方向的兩 端係設有前述第一檢測感測器及第二檢測感測器的輸出訊 號爲不同的區外辨識區域。 (發明之效果） 藉由如上所示所構成之本發明的位置檢測裝置，與前 述第一標度尺相鄰接設有第二標度尺，在該第二標度尺係 以與第一標度尺爲相同的間距配列有指標，並且在前述第 一標度尺或第二標度尺中之指標配列方向的兩端係設有前 述第一檢測感測器及第二檢測感測器之輸出訊號爲不同的 區外辨識區域，因此在各標度尺的兩端，係將第一檢測感 測器的檢測訊號與第二檢測感測器的檢測訊號作比較，藉 此當任一方的感測器進入至前述區外辨識區域時’均可輕 易地判別之。亦即，在本發明之線性致動器中，將輸出第 -8- 201000867 一檢測感測器及第二檢測感測器爲相同的訊號波形 作爲第二構件對第一構件的有效行程區域，藉此可 檢測第二構件偏離有效行程區域的情形，而可立即 述驅動手段。 此外’第一標度尺的指標係以與第二標度尺的 相同的間距而設，因此以該等兩標度尺而言係利用 標度尺，另外將一枚標度尺之長邊方向的兩端與前 辨識區域相對應而作缺口，亦容易將第一標度尺與 度尺統合爲一枚標度尺。此外，以第一檢測感測器 亦可利用與第二檢測感測器爲相同者，相鄰接而設 感測器的配線亦容易收存在例如1枚撓性印刷基板（ 。因此，本發明之位置檢測裝置係一面具備有效行 的檢測功能，一面可極爲精簡地構成，在裝載於線 器時，可有助於其小型化。 此外，對前述第一標度尺及第二標度尺以相同 有複數指標，因此亦可將任一方標度尺的任意指標 述第二構件的控制原點加以設定。例如，在將前述 識區域設在第二標度尺時，暫時將前述第二檢測感 定在第二標度尺的區外辨識區域，之後一面使第二 動，一面以第二檢測感測器讀取第二標度尺的指標 進行計數，藉此將存在於有效行程範圍內的任意指 爲控制原點，以後可一面利用該控制原點，一面進 構件的移動控制。因此，線性致動器的使用者可任 控制原點，可進行適於各個使用者之用途的控制原 的區域 輕易地 停止前 指標爲 相同的 述區外 第二標 而言， 的該等 FPC ) 程範圍 性致動 間距設 作爲前 區外辨 測器設 構件移 ，將其 標設定 行第二 ίΒΒ 思进疋 點的設 -9- 201000867 定。 【實施方式】 以下按照所附圖示’詳加說明本發明之位置檢測裝置 及利用該位置檢測裝置之線性致動器。 第1圖係顯示裝載有本發明之位置檢測裝置之線性致 動器之一例。該線性致動器係由：基底構件1、被舖設在 該基底構件1之上的軌道軌條2、沿著該軌道軌條2可自由 地作往返運動的平台構件3、及將該平台構件3在前述基底 構件1上推進之作爲驅動手段的線性馬達4所構成。 前述基底構件1係具有底板10、及立設在該底板1〇兩 側的一對側壁1 1、1 1而形成爲通道狀，藉由不銹鋼予以製 作。在前述底板1 0係沿著該基底構件1的長邊方向形成有 用以將前述軌道軌條2定位的安裝溝12。 此外，前述平台構件3係由沿著前述軌道軌條2作運動 的2座滑塊5、及被固定在該等滑塊5的平台板件6所構成， 前述滑塊5係與軌道軌條2 —起構成線性導件。藉此，可使 前述平台板件6沿著軌道軌條2自在地作並進運動。 此外，在前述基底構件1之長邊方向的兩端分別固定 有用以防止滑塊5對軌道軌條2越距（overrun)的擋止件23 。該擋止件23係合成樹脂製，跨過前述軌道軌條2而被固 定在基底構件1的底板10。 另一方面，前述線性馬達4係線性同步馬達，由以一 列配列在基底構件1之各側壁1 1的複數定子磁鐵40 ;及與 -10- 201000867 該等定子磁鐵40隔著些微間隙相對向，並且在2座滑塊5之 間被懸掛在前述平台板件6之下側的一對線圈構件4 1所構 成。 在基底構件1的各側壁1 1上，前述定子磁鐵40係以將N 極及S極交替地朝向前述線圈構件4 1的方式作配列。另一 方面，各線圈構件4 1係對由鐵等強磁性體所形成的芯構件 捲繞線圈而形成，將該芯構件的前端部朝向基底構件1的 側壁1 1，亦即朝向定子磁鐵40作配置。各線圈構件41係具 備有u相、v相及w相之三相線圈，對該等線圈通電三相交 流電流’藉此使線圈構件4 1生成移動磁場，對裝載有線圏 構件41的平台構件3，發生沿著定子磁鐵40之配列方向的 推力。 在前述基底構件1之其中一方側壁1 1固定有剖面大致L 字型的支座（bracket ) 13，在該支座13的上面係沿著基底 構件1的長邊方向黏貼有線性標度尺1 4。此外，在前述平 台板件ό的下面’係固定有按照該平台板件6的移動來讀取 前述線性標度尺14之指標的編碼器，且按照平台板件6的 移動速度來輸出檢測訊號。亦即，在該實施形態中，基底 構件1相當於本發明的第一構件’平台構件3相當於本發明 的第二構件。其中’在第1圖中，符號16係內置用以對線 性馬達的線圈構件4 1通電驅動電流的電力線的撓性印刷基 板（FPC )’符號1 7係用以將前述編碼器的檢測訊號傳送 至檢測控制部的F P C。 第2圖係顯示應用本發明之前述線性標度尺i 4與編碼 -11 - 201000867 器1 5之組合之一例的斜視圖。前述線性標度尺丨4係由 前述平台構件3的移動方向而設的第—標度尺14a、及 第一標度尺l4a平行設置的第二標度尺i4b所構成。該 一標度尺14a及第二標度尺14b均爲磁性標度尺，在其 係沿著長邊方向交替充磁有作爲指標的N極及S極。 另一方面，前述編碼器15係內置有與第一標度/ 相對向的第一檢測感測器1 5 a、與第二標度尺1 4 b相對 第二檢測感測器1 5 b的雙方。第一檢測感測器1 5 a及第 測感測器1 5 b係各個內置一對檢測頭，各檢測頭在沿 —標度尺14a及第二標度尺14b的表面移動時，輸出與 變化相對應的檢測訊號。若將磁性標度尺中的N極的 間距設爲P，該檢測訊號即成爲周期與配列間距P相對 擬似正弦波。此外’被裝載於第一檢測感測器1 5a的 檢測頭係沿著磁性標度尺的長邊方向而偏移1 / 4P作 ，以其結果而言，由第一檢測感測器1 5 a所具備的一 測頭所獲得的檢測訊號的輸出電壓，如第3圖所示， 偏移相位1 / 4P的A相（正弦波）及B相（餘弦波）。 檢測感測器1 5b所具備的一對檢測頭亦具有相同的構 同樣地，由第二檢測感測器1 5b所獲得的檢測訊號的 電壓係成爲偏移相位相當於1 / 4P之時間的A相及B相 個訊號波。 第4圖係顯示應用本發明之線性標度尺的第一實 態者，將前述線性標度尺1 4中的磁極配置模式化者。 標度尺14所包含的第一標度尺14a及第二標度尺14b之 沿著 與該 等第 表面 1 4 a 向的 二檢 著第 磁通 配列 應的 一對 配置 對檢 成爲 第二 成， 輸出 的二 施形 線性 中， -12- 201000867 在第一標度尺14 a係遍及其長邊方向的全域配列有磁極， 當將磁通強弱可視化時，如第4圖所示形成有條紋花樣。 另一方面，在前述第二標度尺14b亦與第一標度尺14a同樣 地配列磁極，其相位係與第一標度尺1 4 a的磁極配列相合 致。因此，在第二檢測感測器1 5b與第一檢測感測器1 5a的 檢測訊號係包含有同相位的A相及B相。 但是，在第二標度尺14b分別與前述第一標度尺14a之 長邊方向的兩端相對應設有前述未充磁磁極的一對區外辨 識區域14c。該等區外辨識區域14c係設在基底構件1對平 台構件3之有效行程範圍R0的外側。所謂有效行程範圍R〇 係指平台構件3在不會抵碰擋止件2 3的情形下，可藉由使 用位置檢測裝置的回授控制作來進行動作的區域，前述區 外辨識區域1 4c係被設在有效行程範圍R0與因前述擋止件 23所造成之機械式扣止位置之間。 如上所示之線性標度尺1 4係可使長度不同的二枚磁性 標度尺（第一標度尺14a及第二標度尺14b )彼此相鄰接而 黏貼在前述支座13表面而構成，但是此時，除了前述區外 辨識區域14c以外，必須以第一檢測感測器1 5a與第二檢測 感測器1 5b的輸出訊號恆常成爲相同相位的方式，進行被 配列在第一標度尺14a的磁極與被配列在第二標度尺14b的 磁極的對位。 此外’亦可在備妥第一標度尺14 a及第二標度尺14b的 合計寬幅所對應的寬幅較大的磁性標度尺之後，僅切取與 第二標度尺1 4b之區外辨識區域1 4c相對應的部位而作爲線 -13- 201000867 性標度尺14，且將其黏貼在前述支座13的表面。此外’在 製作線性標度尺1 4時，亦可僅有前述區外辨識區域1 4 c的 部位未將磁極充磁。 第5圖係顯示該線性致動器之控制系統的方塊圖。在 前述線性馬達4係連接有伺服驅動器4 2，該伺服驅動器4 2 係一面與運動控制器（motion controller) 43進彳了通訊* 一面生成線性馬達4的驅動電流。在前述運動控制器4 3係 預先儲放有關於平台構件3的移動方向、移動速度、停止 位置的複數步驟的動作資訊，伺服驅動器42係由運動控制 器43接收關於平台構件3之下一個動作步驟的資訊，而生 成適於此的線性馬達4的驅動電流。 由驅動器電路42對線性馬達4的線圈構件4 1通電驅動 電流時，藉由線性馬達4所發生的推進力，平台構件3會對 基底構件1產生並進運動。另一方面，伴隨著平台構件3的 運動，由前述第一檢測感測器1 5 a及第二檢測感測器1 5所 被輸出的擬似正弦波的檢測訊號A相及B相係被輸入至內插 器（interpolator ) 1 8。內插器1 8係將擬似正弦波的1波長 分別作分割而轉換成高分解的脈衝訊號之後，將與檢測訊 號A相及B相的各個相對應的脈衝訊號作爲位置資訊訊號而 對伺服驅動器42進行輸出。伺服驅動器42係對該位置資訊 訊號的脈衝數進行計數，一面與由運動控制器43所被供予 的該步驟的動作資訊作比較’一面生成線性馬達4的驅動 電流。此外，位置資訊訊號的A相及B相係具有相位偏移， 因此藉由對該等作對比，亦可判斷平台構件3的移動方向 -14 - 201000867 。藉此’可使平台構件3相對基底構件1作移動而任意作定 位。亦即，前述運動控制器43、伺服驅動器42及內插器1 8 構成本發明的驅動控制手段。 此外’內插器1 8係第二檢測感測器1 5b的檢測訊號A相 及B相亦轉換成脈衝訊號’將該等作爲原點資訊訊號而對 伺服驅動器42進行輸出。但是，第二檢測感測器15b存在 於第二標度尺14b的區外辨識區域14c，經轉換後的原點資 訊訊號的A相及B相均成爲基準電壓値時，內插器18係將作 爲警報（alarm )的有效行程外訊號進行輸出。當對平台 構件3的控制原點實施重歸動作時，伺服驅動器4 2係取入 該等原點資訊訊號及有效行程外訊號，與關於預先由運動 控制器43所被供予的控制原點的位置資訊作比較，爲了將 平台構件3設定在控制原點，而生成線性馬達4的驅動電流 〇 該線性致動器的控制系統係採用將相對於控制原點的 平台構件3的位置使用前述位置資訊訊號進行上數（Up Count)或下數（Down Count)之所謂遞增（incremental )方式’在接通電源而開始線性致動器之運轉時，係必須 在最初進行設定控制原點的原點重歸動作。該原點重歸動 作係如以下來進行。其中’在以下說明中，爲了使平台構 件3的移動方向較爲明確’將該移動方向作爲正方向或負 方向加以記載。 S ¥彳控制系統接通電源時，如第6圖所示，首先檢杳 伺服驅動器42是否已由內插器18被輸入有有效行程外訊號 -15- 201000867 (ST1)。若未被輸入有有效行程外訊號，平台構件3係存 在於有效行程範圍R0，一面將平台構件3朝正方向移動（ ST2 )，一面檢查是否已被輸入有效行程外訊號（ST3)， 持續對於正方向的移動直至該訊號被輸入爲止。接著，若 已被輸入有有效行程外訊號，平台構件3係由有效行程範 圍R0脫離’而已到達於存在於正方向的區外辨識區域14c ，因此將平台構件3的移動方向切換成負方向（ST6)。 另一方面，在ST1中若已被輸入有有效行程外訊號， 平台構件3係存在於有效行程範圍R0的外側。但是，無法 判斷是否存在於相較於有效行程範圍更爲正方向側或負方 向側的任一者。因此，使平台構件朝正方向移動（ST4 ) ，檢查線性馬達4的驅動電流是否已超過額定電流的1 〇〇% (S T 5 )。驅動電流超過額定電流的1 0 0 %意指平台構件3 相對於正方向的擋止件2 3作抵碰，因此平台構件3存在於 正方向側的區外辨識區域14c。因此，若由ST5的檢查結果 來判斷出驅動電流已超過額定電流的1 〇〇%時，即將平台構 件3的移動方向切換成負方向（ST6)。 在ST6中，藉由將平台構件3的移動方向切換成負方向 ，平台構件3係進入至有效行程範圍R〇’由內插器18係被 輸出有原點資訊訊號的A相及B相。伺服驅動器42係對該原 點控制資訊進行計數，檢查該計數値是否與預先由運動控 制器4 3所被設定的控制原點資訊相合致（S T 7 )，若相合 致，即停止平台構件3的移動。藉此完成對平台構件3之控 制原點的設定。 -16- 201000867 如上所示，在本發明之線性致動器中，係利用第二標 度尺14b的區外辨識區域14c來進行原點重歸動作，但是在 與第二標度尺14b相鄰接的第一標度尺14 a係在與第二標度 尺14b之區外辨識區域14c相鄰接的區域亦以預定間距P形 成有指標。因此，即使平台構件3存在於有效行程範圍R0 的外側，由內插器1 8所被輸出的原點資訊訊號在A相及B相 均成爲基準電壓値，位置資訊訊號的A相及B相係形成爲與 平台構件3的移動速度相對應的脈衝訊號列，伺服驅動器 4 2係可使用位置資訊訊號來控制平台構件3的移動。 接著，在平台構件3之有效行程範圍R0的內側係在前 述第二標度尺14b亦以與第一標度尺14a相同的間距P配列 有指標，由內插器1 8係被輸出有與該指標相對應的A相及B 相的脈衝訊號列、亦即原點資訊訊號，因此藉由利用該原 點資訊訊號，可在有效行程範圍的任意位置設定控制原點 。亦即，前述第二標度尺14b係具有作爲原點設定用標度 尺的功能。 接著’針對平台構件3的緊急停止控制加以說明。 當對於前述控制系統之輸出入訊號，由外部混入雜訊 時’在前述平台構件3之運轉中，該平台構件3會發生未意 圖地在有效行程範圍R0外側脫離的問題。在第一標度尺 14a係與有效行程範圍R〇無關地設有指標，因此即使平台 構件3脫離在有效行程範圍的外側，亦由內插器1 8係與有 效行程範圍內相同地被輸出有位置資訊訊號，因此伺服驅 動器4 2係照原樣地持續進行平台構件3的移動控制。因此 -17- 201000867 ，在發生如上所示之問題時，係必須立即停止平台構件3 ，在該實施形態之線性致動器中，係如以下所示進行平台 構件3的緊急停止控制。 如第7圖所示，平台構件3實施以前述控制原點爲基準 之預定動作時，運動控制器43係並行檢查內插器is是否已 輸出有效行程外訊號（ST1 1 )。接著，若有效行程外訊號 已由內插器18被輸出，運動控制器43係立即對伺服驅動器 4 2下指令停止線性馬達4 ( S T 1 2 )。藉此，藉由伺服驅動 器42使實施中的控制動作被中斷，平台構件3即會停止。 不過，當對於控制系統的輸出入訊號混入有雜訊時， 會在運動控制器43與伺服驅動器42之通訊可靠性發生疑問 ，因此若由確實停止平台構件3的觀點來看，以在伺服驅 動器42與電源之間設置電源遮斷電路，對該電源遮斷電路 輸入有效行程外訊號爲佳。亦即，當由內插器18被輸出有 有效行程外訊號時，係使用該訊號來使電源遮斷電路動作 ’以遮斷對伺服驅動器42之電力供給。藉此，可使平台構 件3確實地停止。 如以上說明所示，藉由該實施形態之線性致動器，在 第二標度尺14b的兩端設置一對區外辨識區域14c，藉由利 用與該等區外辨識區域1 4c相對應所被輸出的有效行程外 訊號’無須另外設置限制感測器等外部感測器’即可進行 平台構件3的原點重歸動作或緊急停止動作。此外，在第 二標度尺14b係與有效行程範圍內相對應而以與第一標度 尺1 4 a相同間距設置複數指標，因此藉由利用與該指標相 -18- 201000867 對應所得的原點資訊訊號，可將有效行程範圍內之任意位 置作爲平台構件3的控制原點加以利用。 接著’前述第二標度尺14b係與第一標度尺14a相鄰接 而設，讀取該第二標度尺14b的第二檢測感測器1 5b亦與第 —檢測感測器1 5 a相鄰接而設，因此該實施形態的位置檢 測裝置係可構成爲極爲精簡，有助於線性致動器小型化。 此外’前述第二標度尺1 4b係具有與第一標度尺1 4a相同間 距的指標，因此亦可將兩標度尺統合成一枚標度尺，而使 第一標度尺14a的指標與第二標度尺14b的指標連續設置。 亦即，備妥以預定間距形成有指標的一枚線性標度尺，若 使該線性標度尺之長邊方向的兩端角部與前述區外辨識區 域14c相對應而作切取，即完成前述第二標度尺14b與第一 標度尺1 4a形成爲一體的線性標度尺。因此，僅對市面販 售的線性標度尺施行簡單的加工，即可輕易地實施本發明 之位置檢測裝置。 其中，在前述實施形態中，以前述第二檢測感測器 15b而言，與第一檢測感測器15a相同地亦具備有一對檢測 頭，且使用用以輸出相位偏移相當於1 / 4P的時間的A相及 B相的二個訊號波者，但是該第二檢測感測器1 5b即使爲僅 具備有單一檢測頭者亦可。此時，第二檢測感測器1 5 b的 輸出訊號係僅成爲A相的訊號波，但是若該訊號波變化成 基準電壓値，即可判斷爲存在於第二檢測感測器1 5b之區 外辨識區域1 4 c，此外’藉由由前述A相的訊號波生成脈衝 訊號，對該脈衝訊號數進行計數’藉此亦可進行前述之原 -19- 201000867 點重歸動作。 但是，若第二檢測感測器1 5b僅輸出A相的訊號波時， 當平台構件3在有效行程範圍r〇內停止時，亦有該訊號波 成爲基準電壓値的情形，在平台構件3停止途中，無法判 別該平台構件3是否已由有效行程範圍R〇脫離。因此，爲 了即使在平台構件3停止中，亦可判別該平台構件3是否存 在於有效行程範圍R0內，如前述實施形態所示，以第二檢 測感測器1 5b具備有一對檢測頭，以輸出A相及b相之二個 訊號波爲佳。 第8圖係顯示可使用在應用本發明之位置檢測裝置的 線性標度尺的第二實施形態。在第4圖所示之第一實施形 態的線性標度尺1 4中，係在第二標度尺1 4b中的指標的配 列方向的兩端設置區外辨識區域1 4c，但是在該第二實施 形態的線性標度尺2 0中，係在該線性標度尺2 0的其中一端 ，在第一標度尺20A設置區外辨識區域20b，另一方面，在 另一端，係在第二標度尺20c設置區外辨識區域20d。若構 成如上所示之線性標度尺20時，當與第一標度尺20 A相對 向的第一檢測感測器1 5 a存在於區外辨識區域20b時，該第 一檢測感測器1 5a之A相及B相的訊號波係均成爲基準電壓 値，但是從與第二標度尺20c相對向之第二檢測感測器1 5b 係取得由作爲指標之與磁極配列相對應的訊號波 '亦即擬 似正弦波所構成的A相及B相的訊號波。此外，與其相反地 ，當與第二標度尺20c相對向的第二檢測感測器1 5b存在於 區外辨識區域20d時，該第二檢測感測器15b的A相及B相的 -20- 201000867 訊號波係均成爲基準電壓値，但是從與第一標度尺20 A相 對向的第一檢測感測器1 5a係取得作爲指標之與磁極配列 相對應的訊號波、亦即A相及B相的訊號波。 因此，藉由將第一檢測感測器1 5 a所輸出的訊號波與 第二檢測感測器1 5b所輸出的訊號波相比較，來判別平台 構件3是否存在於線性標度尺20的有效行程範圍R0內，而 且，若存在於有效行程範圍R0之外，即可判別位於有效行 程範圍之哪一側之外。因此，前述內插器1 8藉由將第一檢 測感測器1 5a的輸出訊號與第二檢測感測器1 5b的輸出訊號 作比較後的結果，輸出作爲警報的有效行程外訊號。此時 ，關於平台構件3之移動位置的位置資訊訊號係可由第一 檢測感測器15a的輸出訊號生成，亦可由第二檢測感測器 1 5b的輸出訊號生成。例如，當位置資訊訊號由第一檢測 感測器1 5a的輸出訊號所生成時，原點資訊訊號係由第二 檢測感測器的輸出訊號1 5b所生成。 如上所示在本發明之位置檢測裝置中，將第一檢測感 測器15a的輸出訊號與第二檢測感測器15b的輸出訊號爲不 同的區域作爲區外辨識區域而設在線性標度尺的兩端’藉 此無須另外設置限制感測器等外部感測器，即可簡便地進 行平台構件3的原點重歸動作或緊急停止動作。 【圖式簡單說明】 第1圖係顯示可應用本發明之位置檢測裝置之線性致 動器之一例的斜視圖。 -21 - 201000867 第2圖係顯示本發明之位置檢測裝置之實施形態的斜 視圖。 第3圖係顯示位置檢測感測器之輸出訊號變化的曲線 圖。 第4圖係顯示應用本發明之線性標度尺之第一實施形 態的模式圖。 第5圖係顯示使用實施形態之位置檢測裝置之線性致 動器之控制系統的方塊圖。 第6圖係顯示使用實施形態之位置檢測裝置之平台構 件之原點重歸動作的流程圖。 第7圖係顯示使用實施形態之位置檢測裝置之平台構 件之緊急停止控制的流程圖。 第8圖係顯示應用本發明之線性標度尺之第二實施形 態的模式圖。 【主要元件符號說明】 1 :基底構件 2 :軌道軌條 3 :平台構件 4 :線性馬達 5 :滑塊 6 :平台板件 10 :底板 1 1 :側壁 -22- 201000867 1 2 :安裝溝 13 :支座 1 4 :線性標度尺 14a :第一標度尺 14b :第二標度尺 14c :區外辨識區域 15 :編碼器 15a :第一檢測感測器 15b :第二檢測感測器 16 :撓性印刷基板（FPC ) 17 :撓性印刷基板（FPC ) 1 8 :內插器 23 :擋止件 40 :定子磁鐵 41 :線圈構件 42 =伺服驅動器 43 :運動控制器 R0 :有效行程範圍 -23-201000867 VI. Description of the Invention: [Technical Field] The present invention relates to a position for detecting a stroke amount of a moving member to a fixed member, and an actual position of the moving member when feedback control is performed at a stop position A detecting device and a linear actuator using the position detecting device. [Prior Art] It is known that such a position detecting device is disclosed in Japanese Patent Laid-Open No. Hei 6-180203, No. 2006-337212, and the like. Specifically, it is composed of a linear scale to which an optical or magnetic index (index) is attached at a predetermined pitch, and a position detecting sensor that is disposed opposite to the linear scale and reads the aforementioned index. For example, the aforementioned linear scale is fixed to the fixing member of the linear actuator, and the position detecting sensor is fixed to the moving member 'the position detecting sensor is relatively moved to the linear scale' The amount of movement of the member to the aforementioned fixing member. The position detecting sensor includes a pair of detecting heads, and each of the detecting heads outputs a sine wave having a one-period of one pitch of the index when reading the index of the linear scale. Further, the pair of detecting heads are arranged with an integral multiple of the index pitch of the index offset by 1/4 pitch, and the sine wave A phase and the cosine wave B phase having a phase difference of 9 degrees are provided by the detecting heads. Is output. Therefore, by comparing the A phase and the B phase, it is possible to grasp the moving direction of the moving member with respect to the fixed member, and it is also possible to grasp the moving amount of the moving member by the accuracy of the division of the index by the complex division -5 - 201000867. The position detecting device using the linear scale is mainly used for the purpose of feedback control of the position or speed of the moving member, but in actual use, due to the absence of the position detecting device, in order to avoid the foregoing The problem that the moving member is deviated from the predetermined moving range, that is, the effective stroke range, is different from the above-described position detecting device, and there are many cases in which an external switch such as a limit switch is provided at both ends of the effective stroke range. The external opening relationship is used to detect the situation when the moving member is disengaged from the effective stroke range. For example, in the linear actuator, when the signal of the external switch is changed from off to on (,), The signal change is a trigger, and measures such as an emergency stop of the linear actuator can be sought. If there is also a mechanical switch in which the external open relationship causes the output signal to be switched by the contact of the moving member, as disclosed in Japanese Laid-Open Patent Publication No. 2006-337212, there is also a magnetic body and a magnetic sense sensor for detecting the same. The situation of the device. On the other hand, an external switch is not provided in the position detecting device disclosed in Japanese Laid-Open Patent Publication No. Hei 6-180203, and is configured to: count the position detection signal and the count corresponding to both ends of the effective stroke range. For comparison, a measure such as an emergency stop of a linear actuator is obtained based on the result of the comparison. [Prior Art Document] (Patent Document 1) Japanese Patent Laid-Open No. Hei 6-180203 (Patent Document 2) Japanese Patent Application Laid-Open No. 2006-3 3 72 1 [Invention No. 2] SUMMARY OF THE INVENTION (Problems to be Solved by the Invention) However, in order to detect the effective stroke range, as described above, a pair of external switches are separately provided separately from the position detecting device, and the arrangement space of the external switch must be redundantly provided. Or the wiring space may hinder the miniaturization of a machine such as a linear actuator that requires a position detecting device. In addition, instead of using an external switch, only the count 値 of the position detection signal is used to determine the effective stroke range. If it is considered that the position detection signal is disturbed due to some reasons, it is likely that the effective stroke range cannot be correctly recognized. The situation at both ends. Means for Solving the Problems The present invention has been made in view of the above problems, and an object thereof is to provide a linear actuation that can confirm whether a moving member exists within an effective stroke range without using an external switch. A miniaturized position detecting device. That is, the position detecting device of the present invention includes: a first scale that has an index arranged at a predetermined pitch; and a first detecting sensor that is disposed to face the first scale and detects the index; The first scale is disposed adjacent to each other and has a second scale with an index at the same pitch as the first scale; and a second indicator that is disposed opposite to the second scale to detect the indicator The second detecting sensor is configured such that the output signals of the first detecting sensor and the second detecting sensor are different at both ends of the 201000867 indexing direction in the first scale or the second scale. The area outside the identification area. Further, the linear actuator using the position detecting device is provided with: a first member; a second member that can move the first member in a relative advancement; and a driving means for advancing the second member to the first member; a first scale of the first member; a first detecting sensor mounted on the second member; a second member disposed adjacent to the first scale and disposed adjacent to the first scale a second detecting sensor mounted on the second member; and receiving a detection signal outputted by the first detecting sensor and the second detecting sensor to control driving control of the driving means The means 'the output signal of the first detecting sensor and the second detecting sensor is different at the two ends of the indexing direction in the first scale or the second scale. . (Effect of the Invention) With the position detecting device of the present invention configured as described above, a second scale is disposed adjacent to the first scale, and the second scale is coupled to the first scale The scales are indexed with the same pitch, and the first detecting sensor and the second detecting sensor are disposed at both ends of the indexing direction in the first scale or the second scale. The output signals are different out-of-zone identification areas. Therefore, at both ends of each scale, the detection signal of the first detection sensor is compared with the detection signal of the second detection sensor, thereby The sensor can be easily discriminated when it enters the identification area outside the zone. That is, in the linear actuator of the present invention, the output signal of the -8-201000867 detecting sensor and the second detecting sensor are the same as the effective stroke area of the first member to the first member. Thereby, the situation in which the second member deviates from the effective stroke region can be detected, and the driving means can be described immediately. In addition, the indicator of the first scale is set at the same pitch as the second scale, so the scale is used for the two scales, and the long side of the scale is additionally used. The two ends of the direction are notched corresponding to the front identification area, and it is also easy to integrate the first scale and the scale into one scale. In addition, the first detecting sensor may be the same as the second detecting sensor, and the wiring of the sensor adjacent to the sensor may be easily received, for example, by one flexible printed circuit board. The position detecting device is configured to be extremely compact while having an effective line detecting function, and can be reduced in size when mounted on a threader. Further, the first scale and the second scale are provided. The same has a plural index, so any control index of any one of the scales can be set to the control origin of the second component. For example, when the aforementioned identification area is set on the second scale, the second The detection is sensed in the out-of-zone identification area of the second scale, and then the second movement is performed while the second detection sensor reads the index of the second scale, thereby being present in the effective stroke range. Any finger in the inside is the control origin, and the movement control of the member can be performed while using the control origin in the future. Therefore, the user of the linear actuator can control the origin and can perform the use suitable for each user. control The original area is easily stopped before the second indicator of the same area, and the FPC) range of the actuation interval is set as the front-area detector set component, and the target is set to the second line. ΒΒ 思 思 的 的 -9 -9 - 201000867 定. [Embodiment] Hereinafter, a position detecting device and a linear actuator using the position detecting device of the present invention will be described in detail with reference to the accompanying drawings. Fig. 1 is a view showing an example of a linear actuator loaded with the position detecting device of the present invention. The linear actuator is composed of: a base member 1, a rail rail 2 laid on the base member 1, a platform member 3 freely reciprocable along the rail rail 2, and the platform member 3 is constituted by a linear motor 4 as a driving means that is advanced on the base member 1. The base member 1 has a bottom plate 10 and a pair of side walls 1 1 and 1 1 standing on both sides of the bottom plate 1 and formed in a channel shape, and is made of stainless steel. In the base plate 10, a mounting groove 12 for positioning the track rail 2 is formed along the longitudinal direction of the base member 1. Further, the platform member 3 is composed of a two-seat slider 5 that moves along the track rail 2, and a platform plate member 6 that is fixed to the sliders 5, and the slider 5 is attached to the track rail. 2 to form a linear guide. Thereby, the aforementioned deck plate member 6 can be freely moved in parallel along the track rails 2. Further, stoppers 23 for preventing the slider 5 from overrunning the track rails 2 are fixed to both ends of the base member 1 in the longitudinal direction. The stopper 23 is made of synthetic resin and is fixed to the bottom plate 10 of the base member 1 across the rail rail 2 . On the other hand, the linear motor 4 is a linear synchronous motor, and is composed of a plurality of stator magnets 40 arranged in a row on each side wall 1 of the base member 1, and a slight gap between the stator magnets 40 and -10-201000867. Further, a pair of coil members 41 are suspended between the two sliders 5 on the lower side of the platform plate member 6. In each of the side walls 1 of the base member 1, the stator magnet 40 is arranged such that the N pole and the S pole alternately face the coil member 41. On the other hand, each coil member 41 is formed by winding a coil with a core member formed of a ferromagnetic material such as iron, and the tip end portion of the core member faces the side wall 1 of the base member 1, that is, toward the stator magnet 40. Make configuration. Each of the coil members 41 is provided with a three-phase coil of a u-phase, a v-phase, and a w-phase, and a three-phase alternating current is supplied to the coils, thereby generating a moving magnetic field by the coil member 41, and a platform member for loading the wire-clamping member 41. 3. A thrust occurs along the direction in which the stator magnets 40 are arranged. A bracket having a substantially L-shaped cross section is fixed to one of the side walls 1 of the base member 1, and a linear scale 1 is adhered to the upper surface of the base member 1 along the longitudinal direction of the base member 1. 4. In addition, an encoder that reads the index of the linear scale 14 according to the movement of the platform plate 6 is fixed on the lower surface of the platform plate ,, and the detection signal is output according to the moving speed of the platform plate 6. . That is, in this embodiment, the base member 1 corresponds to the first member of the present invention. The platform member 3 corresponds to the second member of the present invention. Wherein, in the first figure, the symbol 16 is a flexible printed circuit board (FPC) in which a power line for driving a current of the coil member 41 of the linear motor is built in. The symbol 17 is used to transmit the detection signal of the encoder. To the FPC of the detection control unit. Fig. 2 is a perspective view showing an example of a combination of the aforementioned linear scale i 4 and the code -11 - 201000867 device 15 to which the present invention is applied. The linear scale 丨 4 is composed of a first scale 14a provided by the moving direction of the platform member 3 and a second scale i4b provided in parallel with the first scale 14a. Each of the scale 14a and the second scale 14b is a magnetic scale, and is alternately magnetized along the longitudinal direction with N and S poles as indices. On the other hand, the encoder 15 has a built-in first detecting sensor 1 5 a opposite to the first scale/, and a second detecting scale 1 5 b opposite to the second detecting sensor 15 b. both sides. The first detecting sensor 1 5 a and the measuring sensor 1 5 b each have a pair of detecting heads, and each detecting head moves along the surfaces of the scale 14a and the second scale 14b, and outputs Change the corresponding detection signal. If the spacing of the N poles in the magnetic scale is set to P, the detection signal becomes a sinusoidal wave with respect to the arrangement pitch P. In addition, the detection head mounted on the first detecting sensor 15a is offset by 1 / 4P along the longitudinal direction of the magnetic scale, and as a result, by the first detecting sensor 15 The output voltage of the detection signal obtained by a probe provided by a, as shown in Fig. 3, is shifted by phase A / 4P of phase A (sine wave) and phase B (cosine wave). The pair of detecting heads provided in the detecting sensor 15b also have the same configuration. The voltage of the detecting signal obtained by the second detecting sensor 15b is equal to the time when the offset phase is equivalent to 1 / 4P. Phase A and Phase B signal waves. Fig. 4 is a view showing the first embodiment of the linear scale to which the present invention is applied, and the magnetic pole arrangement in the aforementioned linear scale 14 is patterned. The first scale 14a and the second scale 14b included in the scale 14 are detected as a second pair along the second surface of the first surface 14a. In the two-shaped linearity of the output, -12- 201000867 has a magnetic pole in the whole range of the first scale 14a and its long-side direction. When the magnetic flux is visualized, as shown in Fig. 4 Striped pattern. On the other hand, the second scale 14b is also arranged with the magnetic poles in the same manner as the first scale 14a, and the phase thereof is aligned with the magnetic pole arrangement of the first scale 14a. Therefore, the detection signals of the second detecting sensor 15b and the first detecting sensor 15a include phase A and phase B of the same phase. However, the pair of out-of-zone discrimination regions 14c of the unmagnetized magnetic poles are respectively provided on the second scale 14b in correspondence with both ends in the longitudinal direction of the first scale 14a. The out-of-zone identification regions 14c are disposed outside the effective stroke range R0 of the base member 1 to the platform member 3. The effective stroke range R〇 refers to a region in which the platform member 3 can be operated by using the feedback control of the position detecting device without the flange member 23 being in contact with the stopper, and the outer region identification region 1 4c It is disposed between the effective stroke range R0 and the mechanically-fastened position caused by the stopper 23 described above. The linear scale 14 shown above is such that two magnetic scales (the first scale 14a and the second scale 14b) having different lengths are adjacent to each other and adhered to the surface of the holder 13 In this case, in addition to the out-of-zone identification area 14c, it is necessary to arrange the output signals of the first detection sensor 15a and the second detection sensor 15b to be in the same phase. The magnetic pole of a scale 14a is aligned with the magnetic pole of the second scale 14b. In addition, after the wide magnetic scale corresponding to the total width of the first scale 14 a and the second scale 14 b is prepared, only the second scale 14 4b is cut out. The portion corresponding to the region identification area 14c is used as the line-13-201000867 scale scale 14, and is adhered to the surface of the aforementioned holder 13. Further, when the linear scale 1 4 is produced, only the portion of the aforementioned outside-identification area 1 4 c may not be magnetized. Figure 5 is a block diagram showing the control system of the linear actuator. A servo driver 42 is connected to the linear motor 4, and the servo driver 42 generates a drive current of the linear motor 4 while communicating with the motion controller 43. In the foregoing motion controller 43, the action information of the plurality of steps regarding the moving direction, the moving speed, and the stop position of the platform member 3 is stored in advance, and the servo driver 42 receives the next action about the platform member 3 by the motion controller 43. The information of the steps generates a drive current for the linear motor 4 suitable for this. When the coil circuit 41 of the linear motor 4 is energized by the driver circuit 42 to drive a current, the platform member 3 generates a parallel movement of the base member 1 by the propulsive force generated by the linear motor 4. On the other hand, along with the movement of the platform member 3, the detection signals A and B phases of the pseudo-sine wave outputted by the first detecting sensor 15a and the second detecting sensor 15 are input. To the interpolator (8). The interpolator 18 divides the 1 wavelength of the pseudo-sine wave into a highly decomposed pulse signal, and then uses the pulse signal corresponding to each of the detection signal A and the B phase as the position information signal to the servo driver. 42 for output. The servo driver 42 counts the number of pulses of the position information signal, and compares the operation information of the step supplied by the motion controller 43 to generate a drive current of the linear motor 4. In addition, the phase A and phase B of the position information signal have a phase shift, so by comparing the same, the moving direction of the platform member 3 can be judged -14 - 201000867. Thereby, the platform member 3 can be arbitrarily positioned relative to the base member 1. That is, the motion controller 43, the servo driver 42, and the interpolator 18 constitute the drive control means of the present invention. Further, the interpolator 18 is a detection signal A phase and a phase B of the second detecting sensor 15b, which are also converted into a pulse signal, which is output as an origin information signal to the servo driver 42. However, the second detecting sensor 15b is present in the out-of-zone identification area 14c of the second scale 14b, and the interpolator 18 is when the A phase and the B phase of the converted origin information signal become the reference voltage 値. It will be output as an effective external signal of the alarm. When the re-homing operation is performed on the control origin of the platform member 3, the servo driver 42 takes in the origin information signals and the valid trip signals, and the control origins that are previously supplied by the motion controller 43. For comparison of the position information, in order to set the platform member 3 at the control origin, a drive current of the linear motor 4 is generated. The control system of the linear actuator adopts the position of the platform member 3 relative to the control origin. The position information signal performs the so-called incremental method of "Up Count" or "Down Count". When the power supply is started and the linear actuator is started, the original control origin must be set. Point back to action. The origin return operation is performed as follows. In the following description, in order to make the moving direction of the platform member 3 clear, the moving direction is described as a positive direction or a negative direction. S ¥ When the control system is powered on, as shown in Fig. 6, first check if the servo driver 42 has been input with the valid trip signal -15- 201000867 (ST1) from the interposer 18. If the valid trip signal is not input, the platform member 3 exists in the effective stroke range R0, and moves the platform member 3 in the positive direction (ST2), and checks whether the valid trip signal (ST3) has been input, and continues to Move in the positive direction until the signal is input. Then, if the effective stroke out signal has been input, the platform member 3 is deviated from the effective stroke range R0 and has reached the out-of-zone identification region 14c existing in the positive direction, thereby switching the moving direction of the platform member 3 to the negative direction ( ST6). On the other hand, if an effective stroke out signal has been input in ST1, the platform member 3 exists outside the effective stroke range R0. However, it cannot be judged whether or not it exists on either the positive side or the negative side of the effective stroke range. Therefore, the platform member is moved in the forward direction (ST4), and it is checked whether the drive current of the linear motor 4 has exceeded 1 〇〇% (S T 5 ) of the rated current. The driving current exceeding 100% of the rated current means that the platform member 3 is opposed to the stopper 2 3 in the positive direction, and therefore the platform member 3 exists in the out-of-zone identification region 14c on the positive side. Therefore, when it is judged from the inspection result of ST5 that the drive current has exceeded 1 〇〇% of the rated current, the moving direction of the stage member 3 is switched to the negative direction (ST6). In ST6, by switching the moving direction of the stage member 3 to the negative direction, the platform member 3 enters the effective stroke range R?', and the interpolator 18 outputs the A phase and the B phase having the origin information signal. The servo driver 42 counts the origin control information, checks whether the count 相 is coincident with the control origin information previously set by the motion controller 43 (ST 7 ), and if so, stops the platform member 3 The movement. Thereby, the setting of the control origin of the platform member 3 is completed. -16- 201000867 As shown above, in the linear actuator of the present invention, the origin re-entry operation is performed by the out-of-zone identification area 14c of the second scale 14b, but in comparison with the second scale 14b The adjacent first scale 14a is also formed with an index at a predetermined pitch P in a region adjacent to the out-of-zone identification area 14c of the second scale 14b. Therefore, even if the platform member 3 exists outside the effective stroke range R0, the origin information signals outputted by the interpolator 18 become the reference voltage A in both the A phase and the B phase, and the A phase and the B phase of the position information signal. The servo signal is formed as a pulse signal train corresponding to the moving speed of the platform member 3, and the servo driver 42 can control the movement of the platform member 3 using the position information signal. Next, in the inner side of the effective stroke range R0 of the platform member 3, the second scale 14b is also indexed at the same pitch P as the first scale 14a, and is outputted by the interpolator 18. The pulse signal sequence of the A phase and the B phase corresponding to the index, that is, the origin information signal, can be used to set the control origin at any position of the effective stroke range by using the origin information signal. In other words, the second scale 14b has a function as a scale for origin setting. Next, the emergency stop control of the platform member 3 will be described. When the input signal to the control system is mixed with noise from the outside, the platform member 3 may be unintentionally detached outside the effective stroke range R0 during the operation of the aforementioned platform member 3. The index is provided on the first scale 14a regardless of the effective stroke range R〇. Therefore, even if the platform member 3 is out of the effective stroke range, the interpolator 18 is output in the same manner as in the effective stroke range. Since there is a position information signal, the servo driver 42 continues the movement control of the platform member 3 as it is. Therefore, -17-201000867, when the problem as described above occurs, the platform member 3 must be stopped immediately. In the linear actuator of this embodiment, the emergency stop control of the platform member 3 is performed as follows. As shown in Fig. 7, when the platform member 3 performs a predetermined operation based on the aforementioned control origin, the motion controller 43 checks in parallel whether or not the interpolator is output a valid external signal (ST1 1 ). Next, if the valid external signal has been output by the interpolator 18, the motion controller 43 immediately instructs the servo driver 4 2 to stop the linear motor 4 (S T 1 2 ). Thereby, the control action in the execution is interrupted by the servo driver 42, and the platform member 3 is stopped. However, when there is noise mixed into the input and output signals of the control system, the reliability of the communication between the motion controller 43 and the servo driver 42 is questioned, so if the platform member 3 is actually stopped, the servo driver is used. A power interruption circuit is provided between the power supply 42 and the power supply, and it is preferable to input a valid external signal to the power supply interruption circuit. That is, when an extra-stroke signal is output from the interpolator 18, the signal is used to cause the power supply to interrupt the circuit' to interrupt the supply of power to the servo driver 42. Thereby, the platform member 3 can be surely stopped. As described above, with the linear actuator of this embodiment, a pair of out-of-band identification regions 14c are provided at both ends of the second scale 14b, by using the identification regions 14c corresponding to the regions. The output external valid signal 'no external sensor such as a limit sensor is required' to perform the home position return operation or the emergency stop action of the platform member 3. Further, the second scale 14b is set to correspond to the effective stroke range and the plural index is set at the same pitch as the first scale 1 4 a, so that the original corresponding to the index -18-201000867 is utilized. The information signal can be used to take any position within the effective range as the control origin of the platform member 3. Then, the second second scale 14b is adjacent to the first scale 14a, and the second detection sensor 15b for reading the second scale 14b is also connected to the first detection sensor 1 Since the positions 5a are adjacent to each other, the position detecting device of this embodiment can be configured to be extremely compact and contribute to miniaturization of the linear actuator. In addition, the aforementioned second scale 14b has an index of the same pitch as the first scale 14a, so that the two scales can be combined into one scale, and the index of the first scale 14a can be made. It is set continuously with the index of the second scale 14b. In other words, a linear scale having an index formed at a predetermined pitch is prepared, and if both end corners in the longitudinal direction of the linear scale are corresponding to the outer recognition region 14c, the cut is completed. The aforementioned second scale 14b is formed as a linear scale with the first scale 14a. Therefore, the position detecting device of the present invention can be easily implemented by simply performing a simple processing on a commercially available linear scale. In the above embodiment, the second detecting sensor 15b is provided with a pair of detecting heads similarly to the first detecting sensor 15a, and is used to output a phase shift equivalent to 1 / 4P. The two signal waves of the A phase and the B phase of the time, but the second detecting sensor 15 b can be even if only a single detecting head is provided. At this time, the output signal of the second detecting sensor 15b is only the signal wave of the A phase, but if the signal wave changes to the reference voltage, it can be determined that it exists in the second detecting sensor 15b. The out-of-area identification area is 1 4 c, and 'the pulse number is counted by generating a pulse signal from the signal wave of the A phase', thereby performing the above-mentioned original -19-201000867 point return operation. However, if the second detecting sensor 15b outputs only the signal wave of the A phase, when the platform member 3 stops within the effective stroke range r〇, the signal wave also becomes the reference voltage ,, in the platform member 3 During the stop, it is impossible to determine whether the platform member 3 has been detached from the effective stroke range R〇. Therefore, in order to determine whether the platform member 3 is present in the effective stroke range R0 even when the platform member 3 is stopped, as shown in the foregoing embodiment, the second detecting sensor 15b is provided with a pair of detecting heads to It is preferable to output two signal waves of phase A and phase b. Fig. 8 is a view showing a second embodiment of a linear scale which can be used in the position detecting device to which the present invention is applied. In the linear scale 1 of the first embodiment shown in FIG. 4, the out-of-zone identification area 14c is provided at both ends of the index direction of the second scale 1b, but in the In the linear scale 20 of the second embodiment, at one end of the linear scale 20, the out-of-zone identification area 20b is disposed on the first scale 20A, and on the other hand, the other end is The second scale 20c sets the out-of-zone identification area 20d. When the linear scale 20 shown above is formed, when the first detecting sensor 15 a opposed to the first scale 20 A exists in the out-of-region identification area 20b, the first detecting sensor The signal waveforms of the A phase and the B phase of 1 5a become the reference voltage 値, but the second detection sensor 15 5 opposite to the second scale 20c is obtained by the column corresponding to the magnetic pole as an index. The signal wave 'is the signal wave of phase A and phase B which are composed of sine waves. Further, conversely, when the second detecting sensor 15b opposed to the second scale 20c exists in the out-of-zone identification area 20d, the A phase and the B phase of the second detecting sensor 15b are - 20- 201000867 The signal wave system becomes the reference voltage 値, but the first detection sensor 15a opposed to the first scale 20 A obtains a signal wave corresponding to the magnetic pole arrangement as an index, that is, A Phase and phase B signal waves. Therefore, whether the platform member 3 exists on the linear scale 20 is discriminated by comparing the signal wave output by the first detecting sensor 15 a with the signal wave output by the second detecting sensor 15 b. Within the effective stroke range R0, and if it exists outside the effective stroke range R0, it can be determined which side of the effective stroke range is outside. Therefore, the interpolator 18 outputs an effective external signal as an alarm by comparing the output signal of the first detecting sensor 15a with the output signal of the second detecting sensor 15b. At this time, the position information signal about the moving position of the platform member 3 can be generated by the output signal of the first detecting sensor 15a or by the output signal of the second detecting sensor 15b. For example, when the position information signal is generated by the output signal of the first detecting sensor 15a, the origin information signal is generated by the output signal 15b of the second detecting sensor. As shown in the above, in the position detecting device of the present invention, the area where the output signal of the first detecting sensor 15a and the output signal of the second detecting sensor 15b are different is set as the out-of-area identification area on the linear scale. Both ends of the platform member 3 can be easily used for the origin return operation or the emergency stop operation of the platform member 3 without separately providing an external sensor such as a limit sensor. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing an example of a linear actuator to which the position detecting device of the present invention is applied. -21 - 201000867 Fig. 2 is a perspective view showing an embodiment of the position detecting device of the present invention. Figure 3 is a graph showing the change in the output signal of the position detecting sensor. Fig. 4 is a schematic view showing a first embodiment of a linear scale to which the present invention is applied. Fig. 5 is a block diagram showing a control system of a linear actuator using the position detecting device of the embodiment. Fig. 6 is a flow chart showing the origin return operation using the platform member of the position detecting device of the embodiment. Fig. 7 is a flow chart showing the emergency stop control of the platform member using the position detecting device of the embodiment. Fig. 8 is a schematic view showing a second embodiment of a linear scale to which the present invention is applied. [Main component symbol description] 1 : Base member 2: Track rail 3: Platform member 4: Linear motor 5: Slider 6: Platform plate 10: Base plate 1 1 : Side wall-22- 201000867 1 2 : Installation groove 13: Support 14: linear scale 14a: first scale 14b: second scale 14c: out-of-zone identification area 15: encoder 15a: first detection sensor 15b: second detection sensor 16 : Flexible printed circuit board (FPC) 17 : Flexible printed circuit board (FPC ) 1 8 : Interposer 23 : Stop member 40 : Stator magnet 41 : Coil member 42 = Servo driver 43 : Motion controller R0 : Effective stroke range -twenty three-