JP2009038320A

JP2009038320A - Reflective photo sensor

Info

Publication number: JP2009038320A
Application number: JP2007203697A
Authority: JP
Inventors: Masahiro Watanabe; 政広渡辺; Jun Sato; 佐藤　　淳
Original assignee: New Japan Radio Co Ltd
Current assignee: New Japan Radio Co Ltd
Priority date: 2007-08-04
Filing date: 2007-08-04
Publication date: 2009-02-19

Abstract

【課題】発光素子と受光素子を用いた簡単な構成で、明暗パターン部材を被検出物側に設けることもなく、被検出物の移動量や移動位置が良好に検出できるようにする。
【解決手段】発光素子１８と受光素子２０が被検出物の移動方向Ｈに沿って配置される場合の受光素子２０に、その活性層を遮光反射膜２８で覆うことにより、上記発光素子１８から離れる程、単位長さ当たりの面積が広くなる受光領域２０Ｅ_１を設ける。このような受光素子２０によれば、被検出物が発光素子１８側から受光素子２０側へ移動するに従って、被検出物からの反射光が入射する領域が徐々に大きくなり、その結果、受光素子２０では被検出物の移動に対応してリニアに変化する光量が検知され、被検出物の移動量等が検出可能になる。上記遮光反射膜２８は、被検出物の移動量が大きくなる程、受光領域２０Ｅ_１への光入射量を増やし、リニアな特性が得られる範囲を拡大する役目をする。
【選択図】図１An object of the present invention is to provide a simple configuration using a light emitting element and a light receiving element, and to detect a moving amount and a moving position of an object to be detected without providing a light / dark pattern member on the object to be detected side.
The light-emitting element and the light-receiving element 20 are arranged along the moving direction H of the object to be detected. A light receiving region 20E ₁ is provided in which the area per unit length increases with increasing distance. According to such a light receiving element 20, as the detected object moves from the light emitting element 18 side to the light receiving element 20 side, the region where the reflected light from the detected object enters gradually increases, and as a result, the light receiving element In 20, the amount of light that linearly changes in response to the movement of the detected object is detected, and the amount of movement of the detected object can be detected. The light shielding reflective film 28, as the movement amount of the object to be detected is increased, increasing the amount of incident light on the light receiving region 20E _1, serves to extend the range of linear characteristics can be obtained.
[Selection] Figure 1

Description

本発明は反射型フォトセンサ、特に発光素子及び受光素子の投受光面を被検出物の移動方向に沿って配置する反射型フォトセンサで、簡単な構成にて、被検出物の移動量や移動位置を検出するためのものに関する。 The present invention is a reflection type photosensor, particularly a reflection type photosensor in which light emitting and receiving surfaces of a light emitting element and a light receiving element are arranged along the moving direction of the object to be detected. It relates to a device for detecting a position.

反射型フォトセンサとして、フォトリフレクタ等があるが、この反射型フォトセンサは、非接触で物体の有無、物体の位置や移動量を検出する光検出器であり、例えばビデオ機器等におけるオーディオテープのスタート位置及びエンド位置の検出、コピー機、プリンターの紙の検出、ＣＤ、ＤＶＤ等の光学ドライブ装置におけるピックアップユニットの位置検出、自動焦点カメラのズーム又はフォーカス動作のレンズ位置検出に用いられる。 As a reflection type photosensor, there is a photo reflector or the like. This reflection type photosensor is a photodetector that detects the presence or absence of an object, the position and movement amount of an object in a non-contact manner, for example, an audio tape of a video device or the like. It is used for detection of a start position and end position, detection of paper in a copying machine and printer, detection of a position of a pickup unit in an optical drive device such as a CD and DVD, and detection of a lens position for zooming or focusing operation of an autofocus camera.

図６（Ａ），（Ｂ）には、従来のフォトリフレクタの構成例が示されており、図６（Ａ）は、フォトリフレクタの上下方向に移動する物体を検出するもの（下記特許文献１）である。このフォトリフレクタは、絶縁基板１、この絶縁基板１上に配置され外周を囲み中間遮光壁部２を有する窓部３、この窓部３と中間遮光壁部２とで形成された一方の凹部に配置された発光素子４、他方の凹部に配置された受光素子５を有してなる。 6A and 6B show a configuration example of a conventional photo reflector, and FIG. 6A detects an object that moves in the vertical direction of the photo reflector (the following Patent Document 1). ). This photoreflector is formed on an insulating substrate 1, a window portion 3 disposed on the insulating substrate 1 and surrounding the outer periphery and having an intermediate light shielding wall portion 2, and one recess formed by the window portion 3 and the intermediate light shielding wall portion 2. It has the light emitting element 4 arrange | positioned and the light receiving element 5 arrange | positioned in the other recessed part.

このような図６（Ａ）のフォトリフレクタでは、上下（矢示Ｕ）方向に移動する被検出物６が鎖線の位置にあるときは、発光素子４から出力された光が中間遮光壁部２で遮られるが、実線の位置にあるときは、発光素子４から出力された光が受光素子５へ到達することになり、この受光素子５での検知状態によって、被検出物６の所定位置における存在が検出される。 In the photoreflector of FIG. 6A, when the detected object 6 moving in the vertical (arrow U) direction is at the position of the chain line, the light output from the light emitting element 4 is the intermediate light shielding wall 2. However, when it is at the position of the solid line, the light output from the light emitting element 4 reaches the light receiving element 5, and depending on the detection state of this light receiving element 5, the object 6 at a predetermined position is detected. Presence is detected.

図６（Ｂ）は、フォトリフレクタの発光素子及び受光素子の配列方向に移動する物体を検出するもの（下記特許文献２）であり、このフォトリフレクタは、実装基板８、この実装基板８上に設けられたフォトリフレクタ９、このフォトリフレクタ９の上方に配置され、スリット１０を形成したスリット機構１１を有してなる。 FIG. 6B is for detecting an object that moves in the direction of arrangement of the light-emitting elements and the light-receiving elements of the photoreflector (the following Patent Document 2). The photoreflector is mounted on the mounting substrate 8 and the mounting substrate 8. The photo reflector 9 is provided, and the slit mechanism 11 is formed above the photo reflector 9 and has a slit 10 formed therein.

このような図６（Ｂ）のフォトリフレクタでは、矢示Ｆの水平方向へ移動する被検出物１２がフォトリフレクタ９の上方の位置に達したときに、フォトリフレクタ９内の発光素子から照射された光がスリット１０を通過して被検出物１２に当たり、その反射光がスリット１０を通過して受光素子で検知されることにより、被検出物１２の存在が検出される。 6B, when the detected object 12 moving in the horizontal direction indicated by the arrow F reaches a position above the photo reflector 9, it is irradiated from the light emitting element in the photo reflector 9. The detected light passes through the slit 10 and strikes the detected object 12, and the reflected light passes through the slit 10 and is detected by the light receiving element, whereby the presence of the detected object 12 is detected.

また、従来において、フォトリフレクタを用いてカメラのレンズの位置を検出するものとして、下記の特許文献３，４があり、これらの文献３，４には、光学系のカムリング等の円筒外周面に、高反射部と遮光部とからなる、反射光量を変化させるパターン（明暗パターン）部材を配置し、フォトリフレクタによって上記パターン部材からの反射光量を検知することにより、光学系（レンズ）の回転位置（ズーム位置）等を検出することが行われている。
特開２００１−１５６３２５号公報特開２００６−１７３３０６号公報特開平５−４５１７９号公報特開２００２−３５７７６２号公報 Conventionally, there are the following Patent Documents 3 and 4 for detecting the position of a camera lens using a photoreflector. These Documents 3 and 4 include a cylindrical outer peripheral surface such as a cam ring of an optical system. Rotating position of the optical system (lens) by arranging a pattern (bright / dark pattern) member that changes the amount of reflected light, consisting of a high reflection part and a light shielding part, and detecting the amount of reflected light from the pattern member with a photo reflector (Zoom position) and the like are detected.
JP 2001-156325 A JP 2006-173306 A JP-A-5-45179 JP 2002-357762 A

しかしながら、上記図６（Ａ），（Ｂ）の従来のフォトリフレクタでは、上下方向又は水平方向に移動する被検出物の存在の有無が検出できるのみで、移動する被検出物の移動量や位置までは検出することができない。 However, the conventional photoreflectors shown in FIGS. 6A and 6B can only detect the presence or absence of a detection object that moves in the vertical direction or the horizontal direction, and the movement amount and position of the detection object that moves. Cannot be detected.

一方、上記特許文献３，４に開示されるように、フォトリフレクタを用いて光学系レンズの回転位置を検出するものでは、高反射部と遮光部とからなる高精度の明暗パターン部材を製作し、これを被検出物側に設けることが必要となり、構成が複雑になるという問題がある。 On the other hand, as disclosed in the above Patent Documents 3 and 4, in order to detect the rotational position of the optical lens using a photo reflector, a high-precision light and dark pattern member composed of a high reflection portion and a light shielding portion is manufactured. It is necessary to provide this on the object to be detected side, and there is a problem that the configuration becomes complicated.

本発明は上記問題点に鑑みてなされたものであり、その目的は、発光素子と受光素子を用いた簡単な構成で、明暗パターン部材を被検出物側に設けることもなく、被検出物の移動量や移動位置を良好に検出することができる反射型フォトセンサを提供することにある。 The present invention has been made in view of the above problems, and its purpose is to provide a simple configuration using a light emitting element and a light receiving element, and without providing a light / dark pattern member on the object to be detected side. An object of the present invention is to provide a reflection type photosensor that can detect the amount and position of movement favorably.

上記目的を達成するために、請求項１に係る発明は、発光部及び受光部の投受光面が、該投受光面に対し平行に移動する被検出物の移動方向に配置され、上記発光部の出力光に基づく上記被検出物からの反射光を上記受光部で受光する反射型フォトセンサにおいて、上記受光部には、その検知出力が、上記被検出物の移動量に応じて直線的に変化するように、上記発光部から離れる程、単位長さ当たりの面積が広くなる受光領域を設けたことを特徴とする。
請求項２に係る発明は、上記受光部の受光領域は、活性部（活性層等で本来の受光面）を部分的に反射体（アルミニウム膜、金属合金膜、反射テープ等）で覆うことにより形成したことを特徴とする。 In order to achieve the above object, the invention according to claim 1 is characterized in that the light projecting and receiving surfaces of the light emitting unit and the light receiving unit are arranged in the moving direction of the detected object that moves parallel to the light projecting and receiving surface. In the reflection type photosensor that receives the reflected light from the detected object based on the output light of the detected light at the light receiving unit, the detection output is linearly corresponding to the amount of movement of the detected object at the light receiving unit. In order to change, a light receiving region is provided in which the area per unit length increases as the distance from the light emitting portion increases.
According to a second aspect of the present invention, the light receiving region of the light receiving portion is formed by partially covering the active portion (the original light receiving surface of the active layer or the like) with a reflector (aluminum film, metal alloy film, reflective tape, or the like). It is formed.

本発明の構成によれば、受光部（受光素子）には、発光部（発光素子）から離れるに従って広がる、例えば左端部から右端部へ広がる面積の受光領域が設けられており、発光部及び受光部の上方において被検出物が発光部側（左側）から受光部側（右側）へ移動するとき、被検出物からの反射光が最初は受光領域の小さな面積の左端部に入射するが、移動するに従って、その入射領域が大きな面積の右端部まで徐々に大きくなる。その結果、受光部では、被検出物の移動に対応して直線的に変化する光量が検知され、この検知光量によって被検出物の移動量又は移動位置が検出できることになる。 According to the configuration of the present invention, the light receiving unit (light receiving element) is provided with a light receiving region having an area that increases from the light emitting unit (light emitting element), for example, from the left end to the right end. When the object to be detected moves from the light emitting part side (left side) to the light receiving part side (right side) above the part, the reflected light from the object to be detected initially enters the left end of the small area of the light receiving region, but moves Accordingly, the incident area gradually increases to the right end of a large area. As a result, the light receiving unit detects the amount of light that linearly changes in response to the movement of the detected object, and the amount or position of movement of the detected object can be detected based on the detected light quantity.

上記請求項２の構成によれば、受光部上面の受光領域以外の領域に当たる被検出物からの反射光を更に反射させることができ、これによって、被検出物の移動量が大きくなる程、反射又は乱反射による光が受光領域に到達することになり、リニアな特性が得られる範囲が拡大されるという利点がある。 According to the configuration of the second aspect, it is possible to further reflect the reflected light from the detected object that hits an area other than the light receiving area on the upper surface of the light receiving unit, and as the amount of movement of the detected object increases, the reflected light increases. Alternatively, light due to irregular reflection reaches the light receiving region, and there is an advantage that the range in which linear characteristics can be obtained is expanded.

本発明の反射型フォトセンサによれば、受光素子サイズやセンサのパッケージサイズを変えることなく、被検出物の移動量とセンサ出力変化の関係がリニアとなる区間を実用的なレベルまで広げることができ、簡単な構成にて、被検出物の移動位置を良好に検出することが可能になるという効果がある。また、従来のカメラに用いられている光学系レンズの位置検出センサのように、明暗パターン部材を被検出物側に設ける必要もない。
上記請求項２の発明によれば、受光部の活性部を反射体で覆う（例えばアルミニウム膜を形成する）だけで、発光部から離れる程、広がる面積の受光領域を形成することができ、センサの製作が極めて容易になるという利点がある。 According to the reflection type photosensor of the present invention, the interval in which the relationship between the amount of movement of the detected object and the change in sensor output is linear can be expanded to a practical level without changing the light receiving element size or the sensor package size. In addition, there is an effect that it is possible to satisfactorily detect the moving position of the detection object with a simple configuration. In addition, unlike a position detection sensor for an optical lens used in a conventional camera, it is not necessary to provide a light / dark pattern member on the detected object side.
According to the second aspect of the present invention, it is possible to form a light-receiving region with an area that increases as the distance from the light-emitting portion increases by simply covering the active portion of the light-receiving portion with a reflector (for example, forming an aluminum film). There is an advantage that the manufacture of the is extremely easy.

図１には、本発明の実施例に係る反射型フォトセンサ（フォトリフレクタ）の構成が示され、図（Ｂ）は図（Ａ）のｂ−ｂ線断面図、図（Ｃ）は図（Ａ）のｃ−ｃ線断面図、図（Ｄ）は受光素子の受光面側の図である。図１（Ａ）〜（Ｃ）に示されるように、実施例の反射型フォトセンサでは、絶縁基板１６上にボンディングパターン１７ａ〜１７ｄが形成されており、ボンディングパターン１７ａに発光部としての発光素子（例えば発光ダイオード）１８、ボンディングパターン１７ｂに受光部としての受光素子（例えばフォトトランジスタ）２０がダイボンディングされ、これら発光素子１８及び受光素子２０は、ボンディングパターン１７ｃ，１７ｄのそれぞれの位置に金ワイヤ２１で接続される。上記絶縁基板１６の裏面には、上記ボンディングパターン１７ａ〜１７ｄのそれぞれに接続された裏面電極２２ａ〜２２ｄが配置される。 FIG. 1 shows a configuration of a reflective photosensor (photoreflector) according to an embodiment of the present invention. FIG. 1 (B) is a cross-sectional view taken along line bb of FIG. 1 (A), and FIG. FIG. 6A is a cross-sectional view taken along the line cc of FIG. 5A, and FIG. 4D is a view on the light receiving surface side of the light receiving element. As shown in FIGS. 1A to 1C, in the reflective photosensor of the embodiment, bonding patterns 17a to 17d are formed on an insulating substrate 16, and a light emitting element as a light emitting portion is formed on the bonding pattern 17a. A light receiving element (for example, a phototransistor) 20 as a light receiving portion is die-bonded to (for example, a light emitting diode) 18 and a bonding pattern 17b, and the light emitting element 18 and the light receiving element 20 are gold wires at respective positions of the bonding patterns 17c and 17d. 21 is connected. On the back surface of the insulating substrate 16, back electrodes 22a to 22d connected to the bonding patterns 17a to 17d, respectively, are disposed.

また、上記発光素子１８及び受光素子２０の周囲を囲うように、所定の高さの外周遮光壁２４が形成されると共に、この発光素子１８と受光素子２０との間に、中間遮光壁２５が設けられ、この外周遮光壁２４と中間遮光壁２５とで囲まれる発光素子１８及び受光素子２０の上側空間は、光を透過する樹脂２６で封止される。そして、この発光素子１８と受光素子２０の投受光面は、該投受光面に対し平行に移動する被検出物の移動方向Ｈに沿って配置される。 Further, an outer peripheral light shielding wall 24 having a predetermined height is formed so as to surround the light emitting element 18 and the light receiving element 20, and an intermediate light shielding wall 25 is provided between the light emitting element 18 and the light receiving element 20. The upper space of the light emitting element 18 and the light receiving element 20 provided and surrounded by the outer peripheral light shielding wall 24 and the intermediate light shielding wall 25 is sealed with a resin 26 that transmits light. The light emitting / receiving surfaces of the light emitting element 18 and the light receiving element 20 are arranged along the moving direction H of the detected object that moves parallel to the light projecting / receiving surface.

図１（Ｄ）に示されるように、上記受光素子２０では、発光素子１８から離れる程、被検出物の移動方向Ｈの単位長さ当たりの面積が広くなる受光領域２０Ｅ_１が設定される。即ち、受光素子２０の活性層（本来の受光面）の上面の左上側を、アルミニウム膜、金属合金膜等からなる遮光反射膜２８で覆う（又は遮光反射テープを貼る）ことにより、本来の受光面（四角形状活性層）がその下辺（Ｘ軸）に沿って徐々に上昇する弧状曲線と右辺（Ｙ軸）に略平行な直線の結合線で仕切られる受光領域２０Ｅ_１が形成される。 As shown in FIG. 1D, in the light receiving element 20, a light receiving region 20 </ b> E ₁ is set in which the area per unit length in the moving direction H of the detection object increases as the distance from the light emitting element 18 increases. That is, the upper left side of the upper surface of the active layer (original light-receiving surface) of the light-receiving element 20 is covered with a light-shielding reflective film 28 made of an aluminum film, a metal alloy film, or the like (or a light-shielding reflective tape is pasted). plane (quadrilateral active layer) is its lower receiving region 20E ₁ partitioned by substantially parallel linear bond line in an arcuate curve and right (Y-axis) that gradually rises along the (X-axis) are formed.

実施例の反射型フォトセンサは、以上の構成からなり、この反射型フォトセンサによる光検知作用を図２により説明する。図２（Ａ）は、被検出物３０が移動方向Ｈで左側から右側へ移動する状態を示しており、被検出物３０が位置Ｐ1 に達したとき、発光素子１８から出力された光が被検出物３０で反射され、受光素子２０（受光領域２０Ｅ_１）へ入射し始め、位置Ｐ2 に達するに従って、受光素子２０に対する被検出物３０の反射光の入射が徐々に多くなる。更に、図２（Ｂ）に示されるように、被検出物３０が移動して位置Ｐ3 ，Ｐ4 ，Ｐ5 へと移動するに従って、図２（Ａ）における受光量に加算される形で、受光素子２０への反射光の入射が増加する。なお、発光素子１８から受光素子２０へ直接入射する光は、中間遮光壁２５で遮蔽される。 The reflection type photosensor of the embodiment has the above-described configuration, and the light detection effect of this reflection type photosensor will be described with reference to FIG. FIG. 2A shows a state in which the detection object 30 moves from the left side to the right side in the movement direction H. When the detection object 30 reaches the position P1, the light output from the light-emitting element 18 is detected. Reflected by the detection object 30 and begins to enter the light receiving element 20 (light receiving region 20E ₁ ), and as the position P2 is reached, the incidence of the reflected light of the detection object 30 on the light receiving element 20 gradually increases. Further, as shown in FIG. 2 (B), as the detected object 30 moves and moves to the positions P3, P4 and P5, the light receiving element is added to the received light amount in FIG. 2 (A). Incidence of reflected light on 20 increases. The light that is directly incident on the light receiving element 20 from the light emitting element 18 is shielded by the intermediate light shielding wall 25.

このような受光素子２０での受光においては、受光領域２０Ｅ_１の面積が発光素子１８から遠ざかる程、即ち右端へ行く程、広くなっていることから、面積が同じ場合に比べると、被検出物３０が右側へ移動する程、受光領域２０Ｅ_１での受光量が増える。即ち、受光領域２０Ｅ_１の広がる面積に応じて受光量が増加する。 In light in such a light-receiving element 20, as the area of the light-receiving region 20E ₁ moves away from the light emitting element 18, i.e. enough to go to the right, since it is wider, the area is compared with the case the same, the object to be detected about 30 moves to the right, the amount of light received by the light receiving region 20E ₁ is increased. That is, the received light amount is increased according to the area of extension of the light receiving region 20E _1.

更に、図２（Ｃ）のように、被検出物３０は位置Ｐ6 へと移動するが、この際には、矢示Ｌ_１で示されるように、発光素子１８から出力され被検出物３０で反射した光が受光素子２０の遮光反射膜２８で反射され、その後被検出物３０で再度反射した光が受光領域２０Ｅ_１に到達する場合や、矢示Ｌ_２で示されるように、外周壁遮光壁２４の内側等で反射された後、再度被検出物３０で反射した光が受光領域２０Ｅ_１に到達する場合等（即ち被検出物３０が発光素子１８及び受光素子２０を覆う程、乱反射も増加する）によって、遮光反射膜２８で反射された光が受光素子２０で検出されるようになる。 Furthermore, as shown in FIG. 2 (C), the will be moved to the object to be detected 30 is located P6, in this case, as indicated by the arrow L _1, off the object 30 is outputted from the light emitting element 18 reflected light is reflected by the light-shielding reflective film 28 of the light receiving element 20, then and if light reflected again off the object 30 reaches the light receiving region 20E _1, as indicated by the arrow L _2, the outer peripheral wall shielding When the light reflected by the detected object 30 reaches the light receiving region 20E ₁ again after being reflected from the inside of the wall 24 or the like (that is, the more the detected object 30 covers the light emitting element 18 and the light receiving element 20, the more irregular reflection occurs). As a result, the light reflected by the light shielding reflection film 28 is detected by the light receiving element 20.

図３には、被検出物の移動量に対するフォトセンサの出力を実施例（Ｃ₁₀₀）と従来例（Ｃ₂₀₀）の相対出力で表したグラフが示されており、従来例では、特性Ｃ₂₀₀に示されるように、リニアな特性が得られる移動範囲がΔＸ1 であったのに対し、本実施例では、特性Ｃ₁₀₀に示されるように、リニアな特性が得られる移動範囲がΔＸ2 と実用的な範囲まで大きく広がっている。なお、このグラフは、図２（Ｄ）に示した形状の受光領域２０Ｅ_１で得られる特性であり、この受光領域の形状を最適なものに設定することにより、リニア特性において更に直線性が高く、移動範囲の広い特性を得ることが可能である。 FIG. 3 shows a graph in which the output of the photosensor with respect to the amount of movement of the object to be detected is represented by the relative output of the example (C ₁₀₀ ) and the conventional example (C ₂₀₀ ). In the conventional example, the characteristic C ₂₀₀ is shown. as shown in, the moving range of the linear characteristic is obtained while was .DELTA.X1, in the present embodiment, as shown in characteristic C _100, the moving range of the linear characteristic is obtained and practical ΔX2 It spreads greatly to such a range. This graph shows the characteristics obtained in the light receiving region 20E ₁ having the shape shown in FIG. 2D. By setting the shape of the light receiving region to an optimum one, the linearity is further increased in linearity. It is possible to obtain characteristics with a wide movement range.

図４には、実施例において、アルミニウム膜からなる遮光反射膜２８を設けた場合（Ｃ₁₀₁）と遮光反射膜を設けない場合（Ｃ₂₀₁）とで被検出物の移動量に対するフォトセンサの出力を比較したグラフが示されており、特性Ｃ₁₀₁のように遮光反射膜２８がある場合は、特性Ｃ₂₀₁のように反射膜がない場合に比べると、被検出物３０の移動量が増す程、即ち被検出物３０が発光素子１８及び受光素子２０を覆う程、フォトセンサの出力が高くなっている。これは、遮光反射膜２８の存在によって、被検出物３０の移動量が大きくなる程、反射又は乱反射による光が受光領域２０Ｅ_１に到達し、リニアな特性が得られる範囲が拡大されることを意味している。 In FIG. 4, in the embodiment, the output of the photosensor with respect to the amount of movement of the detected object when the light-shielding reflective film 28 made of an aluminum film is provided (C ₁₀₁ ) and when the light-shielding reflective film 28 is not provided (C ₂₀₁ ). there is shown a graph comparing the, if there is a light-shielding reflective film 28 as characteristic C _101, as compared to when there is no reflective film as in the characteristic C _201, larger the amount of movement of the detected object 30 increases That is, the output of the photosensor increases as the object 30 covers the light emitting element 18 and the light receiving element 20. This is due to the presence of the light-shielding reflective film 28, as the movement amount of the detected object 30 is large, light by reflection or diffuse reflection reaches the light receiving region 20E _1, that the range of linear characteristics can be obtained is expanded I mean.

図５には、実施例の受光素子２０に形成される受光領域の他の例が示されており、図５（Ａ）は、右辺及び下辺の全体に円弧状の線が形状された遮光反射膜３２を設け、弧状線で仕切った受光領域２０Ｅ_２としたものである。また、この受光領域２０Ｅ_２は、鎖線５０のように斜めの線で仕切ってもよい。図５（Ｂ）は、弧状線が形成された上下２つの遮光反射膜３３を設け、本来の活性層の図の上下方向中心部において発光素子１８から離れる程、ラッパ状に広がる面積の受光領域２０Ｅ_３としたものであり、このような受光領域２０Ｅ_２，２０Ｅ_３によっても、光検出においてリニアな特性を得ることが可能となる。 FIG. 5 shows another example of the light receiving region formed in the light receiving element 20 of the embodiment. FIG. 5A shows a light shielding reflection in which arc-shaped lines are formed on the entire right side and the lower side. A light receiving region 20E ₂ provided with a film 32 and partitioned by an arcuate line is used. Further, the light receiving region 20E ₂ may be partitioned by an oblique line like the chain line 50. FIG. 5B shows a light-receiving region having an area that spreads in a trumpet as the distance from the light-emitting element 18 increases in the center in the vertical direction in the drawing of the original active layer. 20E ₃ and the are those, even by such a light receiving region _20E 2, 20E _3, it is possible in the photodetector to obtain a linear characteristic.

上記実施例では、面実装タイプのフォトリフレクタの構造に適用した例を示したが、この面実装タイプで、外周遮光壁２４がないもの（中間遮光壁２５は必要）や、リードピンタイプ等の他の構造のフォトリフレクタに本発明を適用することができる。
また、実施例では、受光素子２０にフォトトランジスタを使用した例を示したが、受光素子としてフォトダイオードやフォトＩＣを適用してもよい。 In the above embodiment, an example is shown in which the structure is applied to the structure of a surface mount type photoreflector. However, this surface mount type has no outer light shielding wall 24 (intermediate light shielding wall 25 is required), other than a lead pin type. The present invention can be applied to a photoreflector having the following structure.
Moreover, although the example which used the phototransistor for the light receiving element 20 was shown in the Example, you may apply a photodiode and photo IC as a light receiving element.

本発明の実施例に係る反射型フォトセンサの構成を示し、図（Ａ）は上面図、図（Ｂ）は図（Ａ）のｂ−ｂ線断面図、図（Ｃ）は図（Ａ）のｃ−ｃ線断面図、図（Ｄ）は受光素子の受光面側の図である。1A and 1B show a configuration of a reflective photosensor according to an embodiment of the present invention, in which FIG. 1A is a top view, FIG. 1B is a cross-sectional view along line bb in FIG. 1A, and FIG. FIG. 4D is a cross-sectional view taken along the line cc of FIG. 実施例の反射型フォトセンサにより被検出物の移動量等を検出する際の光検知作用を説明するための図である。It is a figure for demonstrating the light detection effect | action at the time of detecting the movement amount etc. of a to-be-detected object with the reflection type photosensor of an Example. 実施例における被検出物の移動量に対するフォトセンサの出力を、実施例（Ｃ₁₀₀）と従来例（Ｃ₂₀₀）の相対出力で表したグラフ図である。The output of the photosensor with respect to the amount of movement of the object to be detected in the example, is a graph showing a relative output of the conventional example as in Example _{_{(C 100) (C 200)}} . 実施例において、遮光反射膜を設けた場合（Ｃ₁₀₁）と遮光反射膜を設けない場合（Ｃ₂₀₁）とで、被検出物の移動量に対するフォトセンサの出力を比較したグラフ図である。In embodiments, if the case of providing the light-shielding reflective film and (C ₁₀₁₎ without the light-shielding reflective film out with (C _201), a graphical diagram comparing the output of the photosensor with respect to the amount of movement of the object to be detected. 実施例の受光素子における受光領域の他の例を示す上面図である。It is a top view which shows the other example of the light reception area | region in the light receiving element of an Example. 従来のフォトリフレクタの２つの構成例を示す図である。It is a figure which shows two structural examples of the conventional photo reflector.

Explanation of symbols

１，１６…絶縁基板、４，１８…発光素子、
５，２０…受光素子、６，１２，３０…被検出物、
１７ａ〜１７ｄ…ボンディングパターン、
２０Ｅ_１〜２０Ｅ_３ …受光領域、
２４…外周遮光壁、２５…中間遮光壁、
２８，３２，３３…遮光反射膜。 1, 16 ... Insulating substrate 4, 18 ... Light emitting element,
5, 20 ... light receiving element 6, 12, 30 ... object to be detected,
17a to 17d: bonding pattern,
20E _{1 to} 20E ₃ ... Light receiving region,
24 ... outer peripheral light shielding wall, 25 ... intermediate light shielding wall,
28, 32, 33 ... Light-shielding reflective film.

Claims

The light projecting and receiving surfaces of the light emitting unit and the light receiving unit are arranged in the moving direction of the detected object that moves parallel to the light projecting and receiving surface, and the reflected light from the detected object based on the output light of the light emitting unit is received by the light receiving unit. In the reflection type photo sensor that receives light at the
The light receiving portion is provided with a light receiving region whose area per unit length increases as the distance from the light emitting portion increases, so that the detection output changes linearly according to the amount of movement of the detected object. A reflective photosensor characterized by the above.

2. The reflective photosensor according to claim 1, wherein the light receiving region of the light receiving portion is formed by partially covering the active portion with a reflector.