200817653 (1) 九、發明說明 【發明所屬之技術領域】 本發明係關於一種作爲產業用機器位置檢測用之感應 器使用之光學式編碼器。 【先前技術】 以往已揭示有對移動刻度，於移動刻度之同一面側， f 配置有光源與受光元件陣列之反射型編碼器（例如，參考 曰本專利文獻1 )。 反射型編碼器由於要將光源與受光元件陣列，配置於 移動刻度之同一面側，故與隔著移動刻度，一列地配置光 源與受光元件陣列之透過型編碼器來比，有適於薄型化之 優點。 圖3爲以往之反射型旋轉編碼器之側剖面圖。 圖中，1爲光源、2爲移動刻度之旋轉碟片、3爲受光 元件陣列、4爲形成於與旋轉碟片2之光源1以及受光元 件陣列3相對向側之表面的符號圖案、6爲旋轉軸、7爲 印刷電路基板、8係半導體感應器基板。 光源1與受光元件陣列3係安裝於未圖示之電動機框 架上，而旋轉碟片2 ’係安裝於對電動機框架（未圖示） 相對變位之旋轉軸6 ° 光源1 一般使用LED。 受光元件陣列3係由光二極體或光電晶體等之光電轉 換元件組成，且因應符號圖案4之間距’配置有已區分之 -4- 200817653 (2) 複數個受光元件。 符號圖案4係增量訊號用之等間距重覆圖案或絕對訊 號用之Μ系列圖案，且於移動刻度之表面形成有反射率高 之金屬薄膜。 接著就動作加以說明。 圖3中，由光源1所射出之光，在形成於旋轉碟片2 之表面之符號圖案4加以反射，而朝受光元件陣列3射入 。受光元件陣列3，將在符號圖案4所調變之光訊號轉換 爲電氣訊號。由受光元件陣3所輸出之電氣訊號，藉由未 圖示之訊號處理電路，轉換爲位置訊號。 〔專利文獻1〕日本特開2005 - 1 2 1 5 93號公報 【發明內容】 〔發明所欲解決之問題〕 然而，以往之反射型編碼器，要縮小旋轉碟片與受光 元件間之間隙時，光線之射入角會變大，且一產生間隙變 動，符號圖案之像則易偏離受光元件位置，而造成檢測訊 號之變動，故難以縮小間隙。 如此之以往的反射型編碼器，由於無法縮小旋轉碟片 之表面與受光元件陣列間之間隙，因此於受光元件陣列上 產生的符號圖案之像的對比會較低，而有所得到訊號之 S/N不佳之問題或不能使裝置薄型化之問題。 本發明係有鑑於上述之課題而硏發的，其目的係在於 提供一種小型’可獲得S/N良好的檢測訊號之光學式編碼 200817653 (3) 器裝置。 〔用以解決問題之手段〕 爲了解決上述問題，本發明係有如下之構造。 申請專利範圍第1項之發明，其係具有： 固定於相對變位之其中一方的構件之光源，以及受光 元件陣列；與 固定於另外一方之構件的移動刻度，且能檢測出上述 2構件之相對性變位， 其特徵爲：上述移動刻度，係以透光性元件形成，而 在上述移動刻度之表面，形成有符號圖案，在上述移動刻 度之背面，形成有反射部。 又，申請專利範圍第2項之發明，其係具有：固定於 相對變位之其中一方的構件之光源、固定縫隙，以及受光 元件；與固定於另外一方之構件的移動刻度，且能檢測出 上述2構件之相對性變位， 其特徵爲：上述移動刻度，係以透光性元件形成，而 在上述移動刻度之表面，形成有符號圖案，在上述移動刻 度之背面，形成有反射部。 又，申請專利範圍第3項之發明，其係一種附編碼器 之電動機，其特徵爲具備有：如申請專利範圍第1項或第 2項之光學式編碼器。 〔發明之效果〕 -6 - 200817653 (4) 根據申請專利範圍第1項或第2項所記載之發明，係 於移動刻度之表面，形成有符號圖案，於移動刻度之背面 ’形成有反射部，所以不會擴大對受光元件陣列或受光元 件之射入角，而能縮小移動刻度與受光元件陣列或受光元 件之間的間隙。因此，可獲得一種小型，且S/N良好的光 學式編碼器裝置。 根據申請專利範圍第3項所記載之發明，其係一種附 編碼器之電動機，其具備有：如申請專利範圍第1項或第 2項之光學式編碼器，故能實現小型之附編碼器之電動機 【實施方式】 〔發明之實施形態〕 以下，參考圖面，說明本發明之實施形態。 實施例1 圖1係顯示本發明之第1實施例的反射型旋轉編碼器 之側剖面圖。 圖中，1爲光源、2爲移動刻度之旋轉碟片、3爲受光 元件陣列。 光源1可用LED或半導體雷射。爲了要提高指向性 ，亦可將準直儀透鏡或圓柱型透鏡等之光學零件加入射出 部。又，不如後述般對受光元件陣列之光線的射入角會變 大，故不僅平行光’即使用擴散光’亦可於得到充分之光 200817653 (5) 強度的指向角內，配置受光元件陣列。 受光元件陣列3係由光二極體或光電晶體等之光電轉 換元件組成，且因應符號圖案4之間距，配置有已區分之 複數個受光元件。 符號圖案4係形成於旋轉碟片2之表面，且係形成有 增量訊號用之等間距重覆圖案或用以檢測出絕對訊號用之 Μ系列圖案等之旋轉位置資訊之圖案。符號圖案4由於係 作爲透過型圖案來使用，因此不須反射光，形成可遮斷光 之透過的金屬或樹脂薄膜即可。 5爲反射部，且反射部5係形成於旋轉碟片2之背面 ，係將鋁或鉻等之金屬薄膜加以蒸鍍，藉此即可容易形成 〇 6爲旋轉軸、7爲搭載有訊號處理電路之印刷基板、8 係半導體感應器基板，設有光源以及受光元件陣列。 本發明與以往技術相異之部分，係於旋轉碟片2之背 面具備有反射部之部分。 接著，就動作加以說明。 圖1中，由光源1所射出之光，一旦通過旋轉碟片2 之中，在旋轉碟片2之反射部5加以反射。在反射部5所 反射的光，透過形成於旋轉碟片2之表面之符號圖案而朝 受光元件陣列3射入。在受光元件陣列3，將受光後之光 量轉換爲電氣訊號。由受光元件陣3所輸出之電氣訊號， 藉由未圖示之訊號處理電路，轉換爲位置訊號。 如此這般，在本實施例中，因形成有通過旋轉碟片中 -8- 200817653 (6) 之光路徑，故不會擴大往受光元件陣列之射入角，而能縮 小旋轉碟片與光源以及受光元件陣列之間的間隙。因此， 可進行編碼器裝置之薄型化。 又，因能縮小旋轉碟片與受光元件陣列之間的間隙， 故不易受到繞射之影響，於受光元件陣列產生之符號圖案 之像的對比較高。因此有所得到訊號之S/N很高之優點。 實施例2 圖2爲顯示本發明之第2實施例的反射型旋轉編碼器 之側剖面圖。 圖中，3 1係因應符號圖案4之間距，而形成有被區分 之縫隙的固定縫隙，其被未圖不之固定構件固疋於印刷電 路基板7。又，32爲受光元件，受光元件32係由光二極 體或光電晶體等之光電轉換元件組成。 本實施例與第1實施例相異之處爲具備有固定縫隙3 1 與受光元件3 2，而非受光元件陣列3。 接著，就動作加以說明。 由光源1所射出之光，一旦通過旋轉碟片2之中，在 旋轉碟片2之反射部5加以反射。在反射部5所反射的光 ，透過旋轉碟片2表面之刻度4與固定縫隙3 1 ’朝受光元 件3 2射入。在受光元件陣列3 2，將受光後之光量轉換爲 電氣訊號。藉由未圖示之電路，可檢測出位置訊號。由受 光元件32所輸出之電氣訊號’藉由訊號處理電路（未圖 示），轉換爲位置訊號。 -9- (7) (7)200817653 如此這般，在本實施例中，因形成有與第1實施例一 樣地能通過旋轉碟片中之光路徑，故不會擴大往受光元件 之射入角，而能縮小旋轉碟片與光源以及固定縫隙之間的 間隙。因此，可進行編碼器裝置之薄型化。 又，因能縮小旋轉碟片與固定縫隙之間的間隙，故不 易受到繞射之影響，於受固定縫隙產生之符號圖案之像的 對比較高。因此有所得到訊號之S/N很高之優點。 另外，本發明除了增量編碼器以外，也能適用於使用 Μ系列圖案之絕對編碼器、將不同間距數之多數磁道加以 組合.而由磁道間之位向差來檢測出絕對位置之游標方式 之絕對編碼器、格雷碼方式之絕對編碼器等之絕對編碼器 〇 又，於旋轉碟片上，形成有多數列之磁道時，對於特 定之磁道，也可適用將來自於旋轉碟片之背面所形成之反 射部的反射光，加以利用之本發明之光學系。例如，於旋 轉碟片上，形成有絕對訊號用之磁道與增量訊號用磁道時 ，對於絕對訊號用之磁道，適用本發明之光學系，也可適 用對於增量訊號用磁道，來檢測出來自增量訊號用磁道之 反射光的以往之光學系。 〔產業上之利用可能性〕 如上述本發明可適用於作爲產業用機械之位置檢測用 感應器，來使用之光學式增量編碼器，以及光學式絕對編 碼器。實施例中，只記述旋轉型之編碼器，但也一樣可適 -10- 200817653 (8) 用線性型之編碼器。 【圖式簡單說明】 第1圖，係顯示本發明之第1實施例的反射型旋轉編 碼器的側剖面圖。 第2圖，係顯示本發明之第2實施例的反射型旋轉編 碼器之側剖面圖。 第3圖，係以往之反射型旋轉編碼器之側剖面圖。 【主要元件符號說明】 1 :光源 2 :旋轉碟片 3 :受光元件陣列 4 ·付號圖案 5 :反射部 6 :旋轉軸 7 :印刷電路基板 8 :半導體感應器基板 3 1 :固定縫隙 32 :受光元件 -11 -BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical encoder used as an inductor for industrial machine position detection. [Prior Art] A reflective encoder in which a light source and an array of light receiving elements are disposed on the same side of the moving scale on the moving scale has been disclosed (for example, refer to Patent Document 1). Since the reflection type encoder is disposed on the same side of the moving scale as the light source and the light receiving element array, it is suitable for thinning by arranging the light source and the transmission type encoder of the light receiving element array in a row with the moving scale interposed therebetween. The advantages. 3 is a side cross-sectional view showing a conventional reflective rotary encoder. In the drawing, 1 is a light source, 2 is a rotating disk of a moving scale, 3 is a light receiving element array, 4 is a symbol pattern formed on a surface opposite to the light source 1 and the light receiving element array 3 of the rotating disk 2, and 6 is The rotating shaft, 7 is a printed circuit board, and an 8-series semiconductor inductor substrate. The light source 1 and the light receiving element array 3 are attached to a motor frame (not shown), and the rotating disk 2' is attached to a rotating shaft 6° which is relatively displaced with respect to a motor frame (not shown). The light-receiving element array 3 is composed of a photoelectric conversion element such as a photodiode or a photoelectric crystal, and a plurality of light-receiving elements are arranged in accordance with the distance between the symbol patterns 4 -4- 200817653 (2). The symbol pattern 4 is a series pattern of equal-pitch repeated patterns for absolute signals or absolute signals, and a metal film having a high reflectance is formed on the surface of the moving scale. Then explain the action. In Fig. 3, the light emitted from the light source 1 is reflected by the symbol pattern 4 formed on the surface of the rotating disk 2, and is incident on the light receiving element array 3. The light-receiving element array 3 converts the optical signal modulated in the symbol pattern 4 into an electrical signal. The electrical signal outputted by the light receiving element array 3 is converted into a position signal by a signal processing circuit not shown. [Patent Document 1] Japanese Laid-Open Patent Publication No. 2005- 1 2 1 5 93 SUMMARY OF THE INVENTION [Problems to be Solved by the Invention] However, in the conventional reflective encoder, when the gap between the rotating disk and the light receiving element is reduced, The incident angle of the light becomes large, and as the gap changes, the image of the symbol pattern tends to deviate from the position of the light-receiving element, and the detection signal changes, so it is difficult to narrow the gap. In such a conventional reflective encoder, since the gap between the surface of the rotating disk and the array of the light receiving elements cannot be reduced, the contrast of the image of the symbol pattern generated on the array of the light receiving elements is low, and the signal S is obtained. The problem of poor /N or the problem of not making the device thin. The present invention has been made in view of the above problems, and an object thereof is to provide an optical encoder having a small detection signal capable of obtaining an excellent S/N signal, 200817653 (3) device. [Means for Solving the Problem] In order to solve the above problems, the present invention has the following configuration. The invention of claim 1, comprising: a light source fixed to one of the members of the relative displacement; and an array of the light receiving elements; and a moving scale fixed to the other member, and capable of detecting the two members The relative displacement is characterized in that the moving scale is formed by a translucent element, and a symbol pattern is formed on the surface of the moving scale, and a reflecting portion is formed on the back surface of the moving scale. Further, the invention of claim 2 includes: a light source fixed to one of the relatively displaced members, a fixed slit, and a light receiving element; and a moving scale fixed to the other member, and capable of detecting The relative displacement of the two members is characterized in that the moving scale is formed by a translucent element, and a symbol pattern is formed on the surface of the moving scale, and a reflecting portion is formed on the back surface of the moving scale. Further, the invention of claim 3, which is an electric motor with an encoder, is characterized by comprising: an optical encoder as claimed in claim 1 or 2. [Effect of the Invention] -6 - 200817653 (4) According to the invention described in the first or second aspect of the patent application, a symbol pattern is formed on the surface of the moving scale, and a reflection portion is formed on the back surface of the moving scale. Therefore, the incident angle to the light-receiving element array or the light-receiving element is not enlarged, and the gap between the moving scale and the light-receiving element array or the light-receiving element can be reduced. Therefore, an optical encoder device which is small and has a good S/N can be obtained. According to the invention of claim 3, the invention relates to an electric motor with an encoder, which is provided with an optical encoder as claimed in claim 1 or 2, so that a small encoder can be realized. [Embodiment] [Embodiment of the Invention] Hereinafter, embodiments of the present invention will be described with reference to the drawings. (First Embodiment) Fig. 1 is a side sectional view showing a reflection type rotary encoder according to a first embodiment of the present invention. In the figure, 1 is a light source, 2 is a rotating disk of a moving scale, and 3 is an array of light receiving elements. The light source 1 can be laser or semiconductor laser. In order to improve the directivity, an optical component such as a collimator lens or a cylindrical lens may be added to the injection portion. Further, since the incident angle of the light of the light-receiving element array is increased as described later, not only the parallel light 'that is, the diffused light' but also the light-receiving element array can be disposed within the directivity angle of the intensity of the sufficient light 200817653 (5). . The light-receiving element array 3 is composed of a photoelectric conversion element such as a photodiode or a photoelectric crystal, and a plurality of divided light-receiving elements are arranged in accordance with the distance between the symbol patterns 4. The symbol pattern 4 is formed on the surface of the rotary disk 2, and is formed with an equally spaced repeating pattern for the incremental signal or a pattern for detecting the rotational position information of the Μ series pattern or the like for the absolute signal. Since the symbol pattern 4 is used as a transmissive pattern, it is not necessary to reflect light, and a metal or resin film which can block the transmission of light can be formed. 5 is a reflection portion, and the reflection portion 5 is formed on the back surface of the rotary disk 2, and a metal thin film such as aluminum or chromium is vapor-deposited, whereby the crucible 6 is easily formed as a rotation axis, and 7 is mounted with a signal processing. The printed circuit board of the circuit and the 8-system semiconductor sensor substrate are provided with a light source and an array of light receiving elements. The portion of the present invention which differs from the prior art is a portion having a reflecting portion on the back surface of the rotary disk 2. Next, the action will be explained. In Fig. 1, the light emitted by the light source 1 is reflected by the reflecting portion 5 of the rotating disk 2 as it passes through the rotating disk 2. The light reflected by the reflecting portion 5 is incident on the light receiving element array 3 through the symbol pattern formed on the surface of the rotating disk 2. In the light-receiving element array 3, the amount of light after receiving light is converted into an electrical signal. The electrical signal outputted by the light receiving element array 3 is converted into a position signal by a signal processing circuit (not shown). In this way, in the present embodiment, since the light path of the -8-200817653 (6) in the disc is formed, the incident angle to the light-receiving element array is not enlarged, and the rotating disc and the light source can be reduced. And a gap between the array of light receiving elements. Therefore, the thickness of the encoder device can be reduced. Further, since the gap between the rotating disk and the light-receiving element array can be reduced, it is less likely to be affected by the diffraction, and the contrast of the image of the symbol pattern generated by the light-receiving element array is high. Therefore, there is an advantage that the S/N of the signal is high. (Embodiment 2) Figure 2 is a side sectional view showing a reflection type rotary encoder according to a second embodiment of the present invention. In the figure, 3 1 is a fixed slit in which a slit is formed in accordance with the distance between the symbol patterns 4, and is fixed to the printed circuit board 7 by a fixing member not shown. Further, 32 is a light receiving element, and the light receiving element 32 is composed of a photoelectric conversion element such as a photodiode or a photoelectric crystal. The present embodiment differs from the first embodiment in that it has a fixed slit 3 1 and a light receiving element 32 instead of the light receiving element array 3. Next, the action will be explained. The light emitted from the light source 1 is reflected by the reflecting portion 5 of the rotating disk 2 once it has passed through the rotating disk 2. The light reflected by the reflecting portion 5 is incident on the light-receiving element 32 through the scale 4 on the surface of the rotating disk 2 and the fixed slit 3 1 '. In the light-receiving element array 32, the amount of light after receiving light is converted into an electrical signal. The position signal can be detected by a circuit not shown. The electrical signal 'outputted by the light receiving element 32' is converted into a position signal by a signal processing circuit (not shown). -9- (7) (7) 200817653 In this way, in the present embodiment, since the light path in the disk can be rotated as in the first embodiment, the entrance to the light receiving element is not enlarged. The angle can reduce the gap between the rotating disc and the light source and the fixed slit. Therefore, the thickness of the encoder device can be reduced. Further, since the gap between the rotating disk and the fixed slit can be narrowed, it is not easily affected by the diffraction, and the contrast of the image of the symbol pattern generated by the fixed slit is high. Therefore, there is an advantage that the S/N of the signal is high. In addition, the present invention can be applied to an absolute encoder using a series of patterns, a combination of a plurality of tracks of different pitch numbers, and a cursor method for detecting an absolute position by a difference in position between tracks. Absolute encoders such as absolute encoders and Gray code absolute encoders, when a plurality of tracks are formed on a rotating disk, for a specific track, it is also applicable to the back of the rotating disk. The reflected light of the formed reflecting portion is used in the optical system of the present invention. For example, when a track for absolute signals and a track for incremental signals are formed on a rotating disk, the optical system of the present invention is applied to a track for absolute signals, and can also be applied to tracks for incremental signals. A conventional optical system from the reflected light of the track for incremental signals. [Industrial Applicability] The present invention is applicable to an optical incremental encoder and an optical absolute encoder which are used as sensors for position detection of industrial machinery. In the embodiment, only the rotary type encoder is described, but the same is also applicable. -10- 200817653 (8) A linear type encoder is used. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side cross-sectional view showing a reflective rotary encoder according to a first embodiment of the present invention. Fig. 2 is a side sectional view showing a reflection type rotary encoder according to a second embodiment of the present invention. Fig. 3 is a side sectional view showing a conventional reflective rotary encoder. [Main component symbol description] 1 : Light source 2 : Rotating disc 3 : Light receiving element array 4 · Pay pattern 5 : Reflecting portion 6 : Rotating shaft 7 : Printed circuit board 8 : Semiconductor sensor substrate 3 1 : Fixed slit 32 : Light-receiving element -11 -