JP5276513B2

JP5276513B2 - Reflective photoelectric sensor

Info

Publication number: JP5276513B2
Application number: JP2009107027A
Authority: JP
Inventors: 真武宇野
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2009-04-24
Filing date: 2009-04-24
Publication date: 2013-08-28
Anticipated expiration: 2029-04-24
Also published as: JP2010258237A

Description

本発明は、光を前方に射出して、検出対象で反射した光を受光する反射型光電センサに関するものである。 The present invention relates to a reflective photoelectric sensor that emits light forward and receives light reflected by a detection target.

図３に従来の反射型光電センサの構成図を示す。従来の反射型光電センサは、投光レンズ１と、投光レンズ１を介して前方に光を射出する投光素子２ａと、受光レンズ３と、受光レンズ３を介して前方から入射する光を受光する受光素子４と、これらの部品を保持するセンサボディ６ａとを備えている。そして、投光素子２ａと受光素子４は基板５に実装され、投光素子２ａおよび受光素子４と投光レンズ１および受光レンズ３は、図３に示すようにセンサボディ６ａによって幾何学的に位置決めされている。なお、本例では、投光レンズ１と受光レンズ３は離間距離ＢＬ１、投光素子２ａと受光素子４は離間距離ＢＬＤ１の位置に配置されている。 FIG. 3 shows a configuration diagram of a conventional reflective photoelectric sensor. The conventional reflective photoelectric sensor includes a light projecting lens 1, a light projecting element 2 a that emits light forward through the light projecting lens 1, a light receiving lens 3, and light incident from the front through the light receiving lens 3. A light receiving element 4 for receiving light and a sensor body 6a for holding these components are provided. The light projecting element 2a and the light receiving element 4 are mounted on the substrate 5, and the light projecting element 2a, the light receiving element 4, the light projecting lens 1 and the light receiving lens 3 are geometrically formed by the sensor body 6a as shown in FIG. It is positioned. In this example, the light projecting lens 1 and the light receiving lens 3 are disposed at a distance BL1, and the light projecting element 2a and the light receiving element 4 are disposed at a distance BLD1.

投光素子２ａは、電流を流すと発光するＬＥＤまたはレーザーダイオードなどで構成されている。受光素子４は、受光面における入射光の位置の移動に応じて出力が変化するＰＳＤ（位置検出素子）または２分割ＰＤ（フォトダイオード）などで構成されている。 The light projecting element 2a is configured by an LED or a laser diode that emits light when an electric current is passed. The light receiving element 4 includes a PSD (position detecting element) or a two-part PD (photodiode) whose output changes in accordance with the movement of the position of incident light on the light receiving surface.

上記の構成からなる本例の反射型光電センサは、投光素子２ａが赤外線などの光を射出すると、その光は、投光レンズ１で集光された後、投光レンズ１から光軸方向の前方にＬ１離れた位置Ｐ１にある検出物体ＤＯで反射して、反射した光は受光レンズ３で集光された後、受光素子４で受光した光に応じて電気信号に変換して出力される。 In the reflective photoelectric sensor of the present example having the above-described configuration, when the light projecting element 2a emits light such as infrared rays, the light is collected by the light projecting lens 1 and then is projected from the light projecting lens 1 in the optical axis direction. The light reflected by the detection object DO at the position P1 that is L1 in front of the light is condensed by the light receiving lens 3, and then converted into an electrical signal according to the light received by the light receiving element 4 and output. The

ところで、このような反射型光電センサでは、投光レンズ１および投光素子２ａの組みと、受光レンズ３および受光素子４の組みとの離間距離により、検出分解能が劣るという課題がある。例えば、投光レンズ１と受光レンズ３の離間距離ＢＬ１および、投光素子２ａと受光素子４の離間距離ＢＬＤ１が短いと、遠方の検出物体の検出分解能が劣る。 By the way, in such a reflection type photoelectric sensor, there exists a subject that detection resolution is inferior by the separation distance of the group of the light projection lens 1 and the light projecting element 2a, and the group of the light receiving lens 3 and the light receiving element 4. For example, when the distance BL1 between the light projecting lens 1 and the light receiving lens 3 and the distance BLD1 between the light projecting element 2a and the light receiving element 4 are short, the detection resolution of a distant detection object is poor.

図４に、遠方の検出物体に対して検出分解能が劣る様子を示す。図４における検出物体ＤＯは、投光レンズ１から光軸方向の前方にＬ２離れた位置Ｐ３にあり、図３における検出物体ＤＯより遠い位置（Ｌ２＞Ｌ１）にある。なお、反射型光電センサの構成は図３と同等の構成である。 FIG. 4 shows a state in which the detection resolution is inferior to a distant detection object. The detection object DO in FIG. 4 is at a position P3 that is L2 away from the light projecting lens 1 in the optical axis direction, and is far from the detection object DO in FIG. 3 (L2> L1). The configuration of the reflective photoelectric sensor is the same as that shown in FIG.

図３に示すように、検出物体ＤＯが位置Ｐ１と位置Ｐ２の間を移動したときの移動距離をΔＬとすると、受光素子４の受光面上の変位はΔＬ１となる。 As shown in FIG. 3, when the moving distance when the detection object DO moves between the position P1 and the position P2 is ΔL, the displacement on the light receiving surface of the light receiving element 4 is ΔL1.

これに対して、図４に示すように、検出物体ＤＯが位置Ｐ３と位置Ｐ４の間を移動したときの移動距離をΔＬとすると、受光素子４の受光面上の変位はΔＬ２となり、このΔＬ２は明らかに図３で示したΔＬ１よりも短くなる。なお、Ｐ１とＰ２の間の距離と、Ｐ３とＰ４の間の距離はΔＬで同じ距離である。 On the other hand, as shown in FIG. 4, when the moving distance when the detection object DO moves between the position P3 and the position P4 is ΔL, the displacement on the light receiving surface of the light receiving element 4 is ΔL2, and this ΔL2 Is clearly shorter than ΔL1 shown in FIG. Note that the distance between P1 and P2 and the distance between P3 and P4 are the same distance ΔL.

すなわち、検出物体ＤＯが遠くにあるほど、同じ距離を移動しても受光素子４の受光面上の変位が幾何学的に小さくなり、受光素子４から出力される電気信号も小さくなり、検出分解能が低下する。 In other words, the farther the detection object DO is, the smaller the displacement on the light receiving surface of the light receiving element 4 geometrically even when the same distance is moved, and the smaller the electrical signal output from the light receiving element 4 is. Decreases.

そこで、遠方にある検出物体ＤＯの検出分解能が向上した反射型光電センサの構成を図５に示す。図５の反射型光電センサは、図３、４に示した反射型光電センサと同様の構成であるが、投光レンズ１と受光レンズ３の離間距離ＢＬ２および、投光素子２ａと受光素子４の離間距離ＢＬＤ２は図３、４のＢＬ１およびＢＬＤ１より長くなるように配置されている。 Therefore, FIG. 5 shows a configuration of a reflective photoelectric sensor in which the detection resolution of a detection object DO located far away is improved. The reflective photoelectric sensor of FIG. 5 has the same configuration as that of the reflective photoelectric sensor shown in FIGS. 3 and 4, but the separation distance BL <b> 2 between the light projecting lens 1 and the light receiving lens 3, and the light projecting element 2 a and the light receiving element 4. The separation distance BLD2 is longer than BL1 and BLD1 in FIGS.

このように、離間距離ＢＬ２、ＢＬＤ２を長くすることで遠方にある検出物体ＤＯの検出分解能を向上することができる。例えば、図５に示すように、検出物体ＤＯが図４と同様に位置Ｐ３と位置Ｐ４の間を移動したときの移動距離をΔＬとすると、受光素子４の受光面上の変位はΔＬ３となり、このΔＬ３は明らかに図４で示したΔＬ２より長くなる。それにより、受光素子４から出力される電気信号が大きくなり、検出分解能が向上する。 Thus, the detection resolution of the detection object DO in the distance can be improved by increasing the separation distances BL2 and BLD2. For example, as shown in FIG. 5, when the movement distance when the detection object DO moves between the position P3 and the position P4 as in FIG. 4 is ΔL, the displacement on the light receiving surface of the light receiving element 4 is ΔL3, This ΔL3 is clearly longer than ΔL2 shown in FIG. Thereby, the electrical signal output from the light receiving element 4 is increased, and the detection resolution is improved.

しかし、図５で示した反射型光電センサには、センサの前方付近で検出物体ＤＯを検出不能な領域（不感帯）が生じるという課題がある。図６に反射型光電センサの不感帯の説明を示す。 However, the reflective photoelectric sensor shown in FIG. 5 has a problem that a region (dead zone) in which the detection object DO cannot be detected is generated near the front of the sensor. FIG. 6 illustrates the dead zone of the reflective photoelectric sensor.

図６の反射型光電センサは、図５に示した反射型光電センサと同様の構成で、検出物体ＤＯがセンサの前面から所定距離Ｌ３の遠端にある位置Ｐ６に検出物体ＤＯがある場合、検出物体ＤＯで反射した光は、受光素子４の受光面の外縁に照射される。そのため、位置Ｐ６より近い範囲（所定距離Ｌ３内）にある位置Ｐ５に検出物体ＤＯがある場合、検出物体ＤＯで反射した光は、受光素子４の受光面外に照射されるので、所定距離Ｌ３内にある検出物体ＤＯを検出することができない。この所定距離Ｌ３が不感帯となり、不感帯の範囲は、離間距離ＢＬ２、ＢＬＤ２を長く設定するほど拡大する。 The reflective photoelectric sensor in FIG. 6 has the same configuration as that of the reflective photoelectric sensor shown in FIG. 5, and when the detected object DO is at a position P6 at the far end of the predetermined distance L3 from the front surface of the sensor, The light reflected by the detection object DO is applied to the outer edge of the light receiving surface of the light receiving element 4. Therefore, when the detection object DO is located at a position P5 within a range closer to the position P6 (within the predetermined distance L3), the light reflected by the detection object DO is irradiated outside the light receiving surface of the light receiving element 4, and therefore the predetermined distance L3. The detected object DO inside cannot be detected. This predetermined distance L3 becomes a dead zone, and the range of the dead zone increases as the separation distances BL2 and BLD2 are set longer.

そこで、近距離用投光素子を用いることによって、不感帯の範囲を縮小した反射型光電センサの構成を図７に示す（例えば特許文献１）。本例の反射型光電センサは、投光レンズ１と、投光レンズ１を介して前方に光を射出する遠距離用投光素子２と、受光レンズ３と、受光レンズを介して前方から入射する光を受光する受光素子４と、前方に光を射出する近距離用投光素子７とをセンサボディ２６内に保持している。そして、遠距離用投光素子２と受光素子４は、基板５に実装されており、投光レンズ１の後方側の焦点に遠距離用投光素子２が配置され、受光レンズ３の後方側の焦点に受光素子４が配置されている。 Therefore, FIG. 7 shows a configuration of a reflective photoelectric sensor in which the range of the dead zone is reduced by using a short-distance light projecting element (for example, Patent Document 1). The reflective photoelectric sensor of this example is incident from the front through a light projecting lens 1, a long distance light projecting element 2 that emits light forward through the light projecting lens 1, a light receiving lens 3, and a light receiving lens. The light receiving element 4 that receives the light to be transmitted and the short-distance light projecting element 7 that emits light forward are held in the sensor body 26. The long distance light projecting element 2 and the light receiving element 4 are mounted on the substrate 5, the long distance light projecting element 2 is disposed at the focal point on the rear side of the light projecting lens 1, and the rear side of the light receiving lens 3. The light receiving element 4 is arranged at the focal point.

センサボディ２６の前面は、同一平面の光透過性材料２６１で形成されており、前方に位置する検出物体が所定距離Ｄ外の遠距離範囲Ｌａにある場合、遠距離用投光素子２から射出された光が検出物体で反射して、その反射光が受光素子４の受光面内に照射され、また前方に位置する検出物体が所定距離Ｄ内の近距離範囲Ｌｂにある場合、近距離用投光素子７から射出された光が検出物体で反射して、その反射光が受光素子４の受光面内に照射されるように、投光レンズ１および遠距離用投光素子２の組みと、受光レンズ３および受光素子４の組みとが離間して配置され、その間に近距離用投光素子７が配置される。また、投光レンズ１および遠距離用投光素子２の組みと近距離用投光素子７との間に仕切り２６２、受光レンズ３および受光素子４の組みと近距離用投光素子７との間に仕切り２６３が形成されている。また、仕切り２６２、２６３の後端は基板５と当接し、前端は光透過性材料２６１と当接するように、前後方向に形成されている。 The front surface of the sensor body 26 is formed of a light transmissive material 261 on the same plane. When the detection object located in front is in the long distance range La outside the predetermined distance D, the light is emitted from the long distance light projecting element 2. When the detected light is reflected by the detection object, the reflected light is irradiated on the light receiving surface of the light receiving element 4, and the detection object located in the front is in the short distance range Lb within the predetermined distance D, the short distance is used. A combination of the light projecting lens 1 and the long distance light projecting element 2 so that the light emitted from the light projecting element 7 is reflected by the detection object and the reflected light is applied to the light receiving surface of the light receiving element 4. The pair of the light receiving lens 3 and the light receiving element 4 are disposed apart from each other, and the short distance light projecting element 7 is disposed therebetween. Further, a partition 262, a combination of the light receiving lens 3 and the light receiving element 4, and the short distance light projecting element 7 are arranged between the combination of the light projecting lens 1 and the long distance light projecting element 2 and the short distance light projecting element 7. A partition 263 is formed therebetween. Further, the rear ends of the partitions 262 and 263 are formed in the front-rear direction so as to abut against the substrate 5 and the front end abuts against the light transmissive material 261.

そして、光透過性材料２６１の後方近傍にある投光レンズ１と受光レンズ３と近距離用投光素子７は、各々の前面と光透過性材料２６１との間の前後方向の距離が略同一となるように配置されている。すなわち、投光レンズ１と受光レンズ３と近距離用投光素子７は、センサボディ２６内で、前後方向における略同一の位置にある。 In the light projecting lens 1, the light receiving lens 3, and the short distance light projecting element 7 in the vicinity of the rear of the light transmissive material 261, the distance in the front-rear direction between each front surface and the light transmissive material 261 is substantially the same. It is arranged to become. That is, the light projecting lens 1, the light receiving lens 3, and the short-distance light projecting element 7 are in substantially the same position in the front-rear direction within the sensor body 26.

上記の構成からなる本例の反射型光電センサは、検出物体が所定距離Ｄ外の遠距離範囲Ｌａにある場合、遠距離用投光素子２によって射出された光は、遠距離範囲Ｌａにある検出物体で反射され、反射した光は受光素子４の受光面上に照射される。また、検出物体が所定距離Ｄ内の近距離範囲Ｌｂにある場合、遠距離用投光素子２によって射出された光は、近距離範囲Ｌｂにある検出物体で反射され、反射した光は受光素子４の受光面外に照射されるが、近距離用投光素子７によって射出された光は、近距離範囲Ｌｂにある検出物体で反射され、反射した光は受光素子４の受光面内に照射される。そのため、遠距離用投光素子２のみでは検出することができなかった、近距離範囲Ｌｂにある検出物体を検出することができる。 In the reflective photoelectric sensor of this example configured as described above, when the detection object is in the long distance range La outside the predetermined distance D, the light emitted by the long distance light projecting element 2 is in the long distance range La. The light reflected by the detection object is irradiated onto the light receiving surface of the light receiving element 4. When the detection object is in the short distance range Lb within the predetermined distance D, the light emitted by the long distance light projecting element 2 is reflected by the detection object in the short distance range Lb, and the reflected light is the light receiving element. 4, the light emitted by the short-distance light projecting element 7 is reflected by the detection object in the short-distance range Lb, and the reflected light irradiates the light-receiving surface of the light-receiving element 4. Is done. Therefore, it is possible to detect a detection object in the short distance range Lb that could not be detected only by the long distance light projecting element 2.

特開２００３−２０４０７７号公報JP 2003-204077 A

図７に示した反射型光電センサにおいて、近距離用投光素子７を用いることによって、不感帯の範囲を近距離範囲Ｌｂ分だけ縮小することができるが、センサボディ６の前面から近距離範囲Ｌｂまでの間の近接範囲Ｌｃが不感帯として残る。 In the reflective photoelectric sensor shown in FIG. 7, the dead zone range can be reduced by the short distance range Lb by using the short distance light projecting element 7, but the short distance range Lb from the front surface of the sensor body 6 can be reduced. The proximity range Lc until is left as a dead zone.

これは、検出物体が近接範囲Ｌｃにある場合、近距離用投光素子７によって射出された光は、近接範囲Ｌｃにある検出物体で反射されるが、反射光の一部がセンサボディ２６の仕切り２６３の前端部２６３ａによって遮光されてしまう。そのため、受光素子４の受光面に照射される光が低下するため、近接範囲Ｌｃにある検出物体を検出することができない。 This is because, when the detection object is in the proximity range Lc, the light emitted by the short-distance light projecting element 7 is reflected by the detection object in the proximity range Lc, but a part of the reflected light of the sensor body 26 The light is shielded by the front end portion 263a of the partition 263. For this reason, since the light irradiated on the light receiving surface of the light receiving element 4 is reduced, it is not possible to detect the detection object in the proximity range Lc.

本発明は、上記事由に鑑みてなされたものであり、その目的は、遠距離範囲にある検出物体の検出分解能を落とさずに、不感帯の範囲を縮小することができる反射型光電センサを提供することにある。 The present invention has been made in view of the above reasons, and an object of the present invention is to provide a reflective photoelectric sensor that can reduce the range of the dead zone without degrading the detection resolution of a detection object in a long distance range. There is.

請求項１の発明は、投光レンズと、当該投光レンズを介して前方に光を射出する遠距離用投光素子と、受光レンズと、当該受光レンズを介して前方から入射する光を受光する受光素子と、前方に光を射出する近距離用投光素子とをセンサボディ内に備え、前方に位置する検出対象と投光レンズ前面との間の距離が所定距離外の遠距離範囲にある場合、遠距離用投光素子から射出された光が遠距離範囲内にある検出対象で反射して、受光素子の受光面内に照射し、前方に位置する検出対象と投光レンズ前面および近距離用投光素子前面との間の距離が所定距離内の近距離範囲にある場合、遠距離用投光素子から射出された光が近距離範囲内にある検出対象で反射して、受光素子の受光面外に照射し、近距離用投光素子から射出された光が近距離範囲内にある検出対象で反射して、受光素子の受光範囲内に照射するように、投光レンズの後方側の焦点に遠距離用投光素子を配置し、受光レンズの後方側の焦点に受光素子を配置し、投光レンズおよび遠距離用投光素子の組みと受光レンズおよび受光素子の組みとが離間して設けられ、その間に近距離用投光素子が設けられる反射型光電センサにおいて、受光レンズの後方側の焦点距離が投光レンズの後方側の焦点距離よりも短く、受光レンズの前面が投光レンズの前面および近距離用投光素子の前面より後方に配置され、受光レンズの前方にあるセンサボディ前面が、投光レンズおよび近距離用投光素子の前方にあるセンサボディ前面よりも後方となるように形成されていることを特徴とする。 According to the first aspect of the present invention, a light projecting lens, a long-distance light projecting element that emits light forward through the light projecting lens, a light receiving lens, and light incident from the front through the light receiving lens are received. A light-receiving element that emits light and a short-distance light projecting element that emits light forward are provided in the sensor body, and the distance between the detection target located in front and the front surface of the light-projecting lens is in a long distance range outside a predetermined distance. In some cases, the light emitted from the long-distance light projecting element is reflected by the detection target within the long-distance range and irradiates the light-receiving surface of the light-receiving element. When the distance to the front surface of the short-range light projecting element is within a short distance range within a predetermined distance, the light emitted from the long-distance light projecting element is reflected by the detection target within the short distance range and received. The light emitted from the light receiving surface of the element and emitted from the light emitting element for short distance is short distance. A long distance light projecting element is arranged at the focal point on the rear side of the light projecting lens so that it is reflected by the detection target in the surroundings and irradiated within the light receiving range of the light receiving element, and received at the focal point on the rear side of the light receiving lens. In a reflective photoelectric sensor in which an element is arranged, a set of a light projecting lens and a long distance light projecting element and a set of a light receiving lens and a light receiving element are provided apart from each other, and a short distance light projecting element is provided therebetween. The focal length on the rear side of the light receiving lens is shorter than the focal length on the rear side of the light projecting lens, and the front surface of the light receiving lens is arranged behind the front surface of the light projecting lens and the front surface of the short distance light projecting element. The front surface of the sensor body is formed so as to be behind the front surface of the sensor body in front of the light projecting lens and the short distance light projecting element.

この発明によれば、受光レンズの前面が投光レンズの前面および近距離用投光素子の前面より後方に配置され、受光レンズの前方にあるセンサボディ前面が、投光レンズおよび近距離用投光素子の前方にあるセンサボディ前面よりも後方となるように、センサボディ前面に段部が形成されていることによって、従来の反射型光電センサよりも不感帯の範囲を縮小することができる。 According to the present invention, the front surface of the light receiving lens is disposed behind the front surface of the light projecting lens and the front surface of the short distance light projecting element, and the front surface of the sensor body in front of the light receiving lens is disposed on the front surface of the light projecting lens. By forming the step portion on the front surface of the sensor body so as to be behind the front surface of the sensor body in front of the optical element, the range of the dead zone can be reduced as compared with the conventional reflective photoelectric sensor.

また、投光レンズの後方側の焦点距離は、受光レンズの後方側の焦点距離よりも長いため、遠距離範囲にある検出対象の検出分解能を落とすことはない。 Further, since the focal length on the rear side of the light projecting lens is longer than the focal length on the rear side of the light receiving lens, the detection resolution of the detection target in the long distance range is not reduced.

請求項２の発明は、請求項１の発明において、前記近距離用投光素子を二個と、前記投光レンズおよび前記遠距離用投光素子の組みを一組と、前記受光レンズおよび前記受光素子の組みを二組とを備え、受光レンズおよび受光素子の各組みの間に投光レンズおよび遠距離用投光素子の組みを配置するとともに、投光レンズおよび遠距離用投光素子の組みと受光レンズおよび受光素子の一方の組みとの間に一方の近距離用投光素子を配置し、投光レンズおよび遠距離用投光素子の組みと受光レンズおよび受光素子の他方の組みとの間に他方の近距離用投光素子を配置することを特徴とする。 According to a second aspect of the present invention, in the first aspect of the invention, two near-field light projecting elements, a pair of the light projecting lens and the long distance light projecting element, the light receiving lens, Two sets of light receiving elements are provided, and a set of a light projecting lens and a long distance light projecting element is disposed between each pair of the light receiving lens and the light receiving element, and the light projecting lens and the long distance light projecting element One short distance light projecting element is disposed between the light receiving lens and one of the light receiving elements, and the light projecting lens and the long distance light projecting element and the other light receiving lens and the light receiving element are combined. The other short distance light projecting element is arranged between the two.

この発明によれば、受光レンズおよび受光素子の組みを二組備えることによって、センサ近傍における検出可能領域を拡大することができ、安定して検出することが可能となる。 According to the present invention, by providing two sets of the light receiving lens and the light receiving element, the detectable region in the vicinity of the sensor can be expanded, and stable detection can be performed.

以上説明したように、本発明では、遠距離範囲にある検出物体の検出分解能を落とさずに、不感帯の範囲を縮小することができるという効果がある。 As described above, according to the present invention, there is an effect that the range of the dead zone can be reduced without reducing the detection resolution of the detection object in the long distance range.

本発明の反射型光電センサの実施形態１の概略構成を示す断面図である。It is sectional drawing which shows schematic structure of Embodiment 1 of the reflection type photoelectric sensor of this invention. 同上の実施形態２の概略構成を示す断面図である。It is sectional drawing which shows schematic structure of Embodiment 2 same as the above. 従来の反射型光電センサの概略構成を示す図である。It is a figure which shows schematic structure of the conventional reflective photoelectric sensor. 同上の遠距離範囲における検出を示す概略構成図である。It is a schematic block diagram which shows the detection in the long distance range same as the above. 同上の遠距離範囲の検出分解能の向上を示す概略構成図である。It is a schematic block diagram which shows the improvement of the detection resolution of a long distance range same as the above. 同上の近距離範囲の不感帯を示す概略構成図である。It is a schematic block diagram which shows the dead zone of the short distance range same as the above. 同上の近接範囲の不感帯を示す概略構成断面図である。It is a schematic structure sectional view showing the dead zone of the proximity range same as the above.

以下、本発明の実施の形態を図面に基づいて説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

（実施形態１）
本発明の実施形態１の反射型光電センサの構成図を図１に示す。投光レンズ１と、投光レンズ１を介して前方に光を射出する遠距離用投光素子２と、受光レンズ３と、受光レンズ３を介して前方から入射する光を受光する受光素子４と、前方に光を射出する近距離用投光素子７とをセンサボディ６内に保持している。そして、遠距離用投光素子２と受光素子４は、基板５に実装されており、投光レンズ１の後方側の焦点に遠距離用投光素子２が配置され、受光レンズ３の後方側の焦点に受光素子４が配置されている。ここで、受光レンズ３の後方側の焦点距離ｆ２は、投光レンズ１の後方側の焦点距離ｆ１よりも短いため、受光レンズ３は、投光レンズ１よりも後方に配置されている。また、基板５はセンサボディ６の後面に配置されている。 (Embodiment 1)
The block diagram of the reflective photoelectric sensor of Embodiment 1 of this invention is shown in FIG. A light projecting lens 1, a long distance light projecting element 2 that emits light forward through the light projecting lens 1, a light receiving lens 3, and a light receiving element 4 that receives light incident from the front through the light receiving lens 3. The short-distance light projecting element 7 that emits light forward is held in the sensor body 6. The long distance light projecting element 2 and the light receiving element 4 are mounted on the substrate 5, the long distance light projecting element 2 is disposed at the focal point on the rear side of the light projecting lens 1, and the rear side of the light receiving lens 3. The light receiving element 4 is arranged at the focal point. Here, since the focal length f2 on the rear side of the light receiving lens 3 is shorter than the focal length f1 on the rear side of the light projecting lens 1, the light receiving lens 3 is disposed behind the light projecting lens 1. The substrate 5 is disposed on the rear surface of the sensor body 6.

センサボディ６の前面は、光透過性材料６１で形成されており、前方に位置する検出物体が所定距離Ｄ１外の遠距離範囲ＬＬ１にある場合、遠距離用投光素子２から射出された光が検出物体で反射して、その反射光が受光素子４の受光面内に照射され、前方に位置する検出物体が所定距離Ｄ１内にある場合、遠距離用投光素子２から射出された光が検出物体で反射して、その反射光が受光素子４の受光面外に照射され、また前方に位置する検出物体が所定距離Ｄ２内の近距離範囲ＬＬ２にある場合、近距離用投光素子７から射出された光が検出物体で反射して、その反射光が受光素子４の受光面内に照射されるように、投光レンズ１および遠距離用投光素子２の組みと、受光レンズ３および受光素子４の組みとが離間して配置され、その間に近距離用投光素子７が配置される。また、投光レンズ１および遠距離用投光素子２の組みと近距離用投光素子７との間に仕切り６２、受光レンズ３および受光素子４の組みと近距離用投光素子７との間に仕切り６３が基板５に実装されている。 The front surface of the sensor body 6 is formed of a light-transmitting material 61, and light emitted from the long-distance light projecting element 2 when the detection object located in the front is in the long-distance range LL1 outside the predetermined distance D1. Is reflected by the detection object, and the reflected light is irradiated on the light receiving surface of the light receiving element 4, and when the detection object located in the front is within the predetermined distance D1, the light emitted from the long distance light projecting element 2 Is reflected by the detection object, and the reflected light is irradiated to the outside of the light receiving surface of the light receiving element 4, and when the detection object located in the front is in the short distance range LL2 within the predetermined distance D2, the light projecting element for short distance The combination of the light projecting lens 1 and the long distance light projecting element 2 and the light receiving lens so that the light emitted from the light 7 is reflected by the detection object and the reflected light is applied to the light receiving surface of the light receiving element 4. 3 and the set of light receiving elements 4 are spaced apart from each other. Distance light projecting element 7 is arranged. Further, the partition 62, the light receiving lens 3 and the light receiving element 4, and the short distance light projecting element 7 are arranged between the light projecting lens 1 and the long distance light projecting element 2 and the short distance light projecting element 7. A partition 63 is mounted on the substrate 5 therebetween.

また、センサボディ６は断面が略矩形状に形成されており、センサボディ６の前面に光透過性材料からなるカバー６１が覆設されている。そして、カバー６１は、受光レンズ３の前方に配置されているカバー６１ａと、投光レンズ１および近距離用投光素子７の前方に配置されているカバー６１ｂとで構成されており、カバー６１ａはカバー６１ｂよりも後方となるように配置されている。そして、カバー６１ａ、６１ｂの後方近傍にある投光レンズ１と受光レンズ３と近距離用投光素子７は、各々の前面とカバー６１ａ、６１ｂとの間の前後方向の距離が略同一となるように配置されている。すなわち、受光レンズ３は、投光レンズ１および近距離用投光素子７よりも後方に配置されている。 The sensor body 6 has a substantially rectangular cross section, and a cover 61 made of a light transmissive material is covered on the front surface of the sensor body 6. The cover 61 includes a cover 61a disposed in front of the light receiving lens 3, and a cover 61b disposed in front of the light projecting lens 1 and the short distance light projecting element 7, and the cover 61a. Is arranged behind the cover 61b. The light projecting lens 1, the light receiving lens 3, and the short distance light projecting element 7 in the vicinity of the rear of the covers 61a and 61b have substantially the same distance in the front-rear direction between the front surface and the covers 61a and 61b. Are arranged as follows. That is, the light receiving lens 3 is arranged behind the light projecting lens 1 and the short distance light projecting element 7.

また、センサボディ６内で基板５に実装されている仕切り６２は、前端がカバー６１ｂと当接するように前後方向に形成されており、仕切り６３は、前端がカバー６１ａ、６１ｂの両者に当接するように前後方向に形成されている。ここで、仕切り６３の前端部６３ａは、前端部６３ａが略Ｌ字状となる段部６３ｂが形成されている。 In addition, the partition 62 mounted on the substrate 5 in the sensor body 6 is formed in the front-rear direction so that the front end contacts the cover 61b, and the partition 63 contacts the covers 61a and 61b at the front end. Is formed in the front-rear direction. Here, the front end portion 63a of the partition 63 is formed with a step portion 63b in which the front end portion 63a is substantially L-shaped.

そして、センサボディ６の側面６４において、受光側の側面６４ａの前端と、仕切り６３の段部６３ｂの後段との間に、カバー６１ａが覆設されている。また、投光側の側面６４ｂの前端と、仕切り６３の段部６３ｂの前段との間に、カバー６１ｂが覆設されている。 In the side surface 64 of the sensor body 6, a cover 61 a is provided between the front end of the light receiving side surface 64 a and the rear stage of the step 63 b of the partition 63. Further, a cover 61 b is provided between the front end of the side surface 64 b on the light projecting side and the front stage of the step part 63 b of the partition 63.

遠距離用投光素子２は、電流を流すと発光するＬＥＤまたはレーザーダイオードなどで構成されている。受光素子４は、受光面における入射光の位置の移動に応じて出力が変化するＰＳＤ（位置検出素子）または２分割ＰＤ（フォトダイオード）などで構成されている。また、近距離用投光素子７は、レンズ付き砲弾タイプのＬＥＤまたはチップタイプのＬＥＤで構成されている。 The long-distance light projecting element 2 includes an LED or a laser diode that emits light when an electric current is passed. The light receiving element 4 includes a PSD (position detecting element) or a two-part PD (photodiode) whose output changes in accordance with the movement of the position of incident light on the light receiving surface. The short-distance light projecting element 7 is composed of a bullet-type LED with a lens or a chip-type LED.

上記の構成からなる本実施形態は、検出物体が遠距離範囲ＬＬ１にある場合、遠距離用投光素子２から射出された光が投光レンズ１で集光された後、前方に射出されて検出物体で反射して、反射光が受光レンズ３で集光された後、受光素子４の受光面内に照射され、受光した光に応じて電気信号に変換され、検出物体の有無または検出物体の距離などを検出信号として出力する。また、検出物体が近距離範囲ＬＬ２にある場合、近距離用投光素子７から射出された光が検出物体で反射して、反射光が受光レンズ３で集光された後、受光素子４の受光面内に照射され、受光した光に応じて電気信号に変換され、検出物体の有無または検出物体の距離などを検出信号として出力する。 In the present embodiment configured as described above, when the detection object is in the long distance range LL1, the light emitted from the long distance light projecting element 2 is condensed by the light projecting lens 1 and then emitted forward. After being reflected by the detection object and condensed by the light receiving lens 3, the reflected light is irradiated on the light receiving surface of the light receiving element 4 and converted into an electrical signal according to the received light, and the presence or absence of the detection object or the detection object Are output as detection signals. When the detection object is in the short distance range LL2, the light emitted from the short distance light projecting element 7 is reflected by the detection object, and the reflected light is collected by the light receiving lens 3, and then the light receiving element 4 Irradiated within the light receiving surface and converted into an electrical signal in accordance with the received light, the presence or absence of the detection object or the distance of the detection object is output as a detection signal.

ここで、遠距離用投光素子２で検出可能な遠距離範囲ＬＬ１および、近距離用投光素子７で検出可能な近距離範囲ＬＬ２は、図７で示した従来の反射型光電センサの遠距離用投光素子２で検出可能な遠距離範囲Ｌａおよび、近距離用投光素子７で検出可能な近距離範囲Ｌｂよりも後方に広い範囲（ＬＬ１＞Ｌａ、ＬＬ２＞Ｌｂ）となっている。これは、受光レンズ３の位置を従来よりも後方に配置することによって、仕切り６３の前端部６３ａに段部６３ｂを形成することができる。そして、この段部６３ｂによって、従来の反射型光電センサでは、近接距離Ｌｃにある検出物体からの反射光を仕切り２６３の前端部２６３ａによって遮光していた部位（図７参照）に、図１に示す空間６３ｃが生じる。 Here, the long-distance range LL1 that can be detected by the long-distance light projecting element 2 and the short-distance range LL2 that can be detected by the short-distance light projecting element 7 are the far distances of the conventional reflective photoelectric sensor shown in FIG. It is a wide range (LL1> La, LL2> Lb) behind the long distance range La detectable by the distance light projecting element 2 and the short distance range Lb detectable by the short distance light projecting element 7. . This is because the step 63b can be formed on the front end 63a of the partition 63 by arranging the position of the light receiving lens 3 behind the conventional lens. Then, in the conventional reflective photoelectric sensor, the reflected light from the detection object at the close distance Lc is shielded by the front end 263a of the partition 263 (see FIG. 7) by the step 63b, as shown in FIG. A space 63c shown is created.

したがって、従来の反射型光電センサの近距離範囲Ｌｂよりセンサに近い距離にある、近距離範囲ＬＬ２の後端に検出物体が存在する場合の反射光Ｂ１は、空間６３ｃを通過して、受光レンズ３に入射することができる。 Therefore, the reflected light B1 when the detection object is present at the rear end of the short distance range LL2, which is closer to the sensor than the short distance range Lb of the conventional reflective photoelectric sensor, passes through the space 63c and is received by the light receiving lens. 3 can be incident.

このように、反射光が空間６３ｃを通過することによって、受光レンズ３に反射光が入射する角度が拡大するため、近距離用投光素子７で検出可能な近距離範囲ＬＬ２は後方に拡大され、不感帯である近接距離をＬＬ３まで縮小される。この不感帯ＬＬ３は、図７で示した従来の反射型光電センサの不感帯Ｌｃよりも、縮小（ＬＬ３＜Ｌｃ）されている。 In this way, since the reflected light passes through the space 63c, the angle at which the reflected light is incident on the light receiving lens 3 is expanded, so that the short distance range LL2 that can be detected by the short distance light projecting element 7 is expanded backward. The proximity distance that is the dead zone is reduced to LL3. This dead zone LL3 is reduced (LL3 <Lc) from the dead zone Lc of the conventional reflective photoelectric sensor shown in FIG.

また、投光レンズ１と投光素子２の離間距離は従来の反射型光電センサと同一なため、遠距離範囲ＬＬ１にある検出物体の検出分解能が低下することはない。 Further, since the separation distance between the light projecting lens 1 and the light projecting element 2 is the same as that of the conventional reflective photoelectric sensor, the detection resolution of the detection object in the long distance range LL1 does not decrease.

このように、１台の反射型光電センサで近距離範囲の不感帯を縮小することができ、別の反射型光電センサと併用する必要がないので、コストを下げることが可能となる。 In this way, the dead zone in the short-range range can be reduced with one reflection type photoelectric sensor, and it is not necessary to use with another reflection type photoelectric sensor, so that the cost can be reduced.

（実施形態２）
本発明の実施形態２の反射型光電センサの構成図を図２に示す。本発明の実施形態２の反射型光電センサは、実施形態１の反射型光電センサと同様の構成であるが、受光レンズ３および受光素子４の組みを二組と、近距離用投光素子７を二個備えていることが特徴である。 (Embodiment 2)
The block diagram of the reflective photoelectric sensor of Embodiment 2 of this invention is shown in FIG. The reflective photoelectric sensor according to the second embodiment of the present invention has the same configuration as that of the reflective photoelectric sensor according to the first embodiment, but includes two sets of the light receiving lens 3 and the light receiving element 4 and a short distance light projecting element 7. It is characterized by having two.

本実施形態は、近距離用投光素子７を二個と、投光レンズ１および遠距離用投光素子２の組みを一組と、受光レンズ３および受光素子４の組みを二組とをセンサボディ１６内に保持している。 In the present embodiment, two short distance light projecting elements 7, one set of the light projecting lens 1 and the long distance light projecting element 2, and two sets of the light receiving lens 3 and the light receiving element 4 are combined. It is held in the sensor body 16.

そして、受光レンズ３および受光素子４の各組みの間に、投光レンズ１および遠距離用投光素子２の組みを配置するとともに、投光レンズ１および遠距離用投光素子２の組みと受光レンズ３および受光素子４の一方の組みとの間に一方の近距離用投光素子７を配置し、投光レンズ１および遠距離用投光素子２の組みと受光レンズ３および受光素子４の他方の組みとの間に他方の近距離用投光素子７を配置している。また、投光レンズ１および遠距離用投光素子２の組みと各近距離用投光素子７との間に仕切り１６２、受光レンズ３および受光素子４の各組みと各近距離用投光素子７との間に仕切り１６３が基板５に実装されている。 A pair of the light projecting lens 1 and the long distance light projecting element 2 is arranged between each pair of the light receiving lens 3 and the light receiving element 4, and the light projecting lens 1 and the long distance light projecting element 2 are combined. One short distance light projecting element 7 is disposed between one set of the light receiving lens 3 and the light receiving element 4, and the light projecting lens 1 and the long distance light projecting element 2 are combined with the light receiving lens 3 and the light receiving element 4. The other short-distance light projecting element 7 is arranged between the other set. Further, a partition 162, each set of the light receiving lens 3 and the light receiving element 4, and each short distance light projecting element between the pair of the light projecting lens 1 and the long distance light projecting element 2 and each short distance light projecting element 7. 7, a partition 163 is mounted on the substrate 5.

また、センサボディ１６は断面が略矩形状に形成されており、センサボディ１６の前面に光透過性材料からなるカバー１６１が覆設されている。そして、カバー１６１は、各受光レンズ３の前方に配置されている一対のカバー１６１ａと、投光レンズ１および各近距離用投光素子７の前方に配置されているカバー１６１ｂとで構成されており、各カバー１６１ａはカバー１６１ｂよりも後方となるよう配置されている。そして、カバー１６１ａ、１６１ｂの後方近傍にある投光レンズ１と各受光レンズ３と各近距離用投光素子７は、各々の前面とカバー１６１ａ、１６１ｂとの間の前後方向の距離が略同一となるように配置されている。すなわち、各受光レンズ３は、投光レンズ１および各近距離用投光素子７よりも後方に配置されている。 The sensor body 16 has a substantially rectangular cross section, and a cover 161 made of a light transmissive material is covered on the front surface of the sensor body 16. The cover 161 includes a pair of covers 161 a disposed in front of each light receiving lens 3 and a cover 161 b disposed in front of the light projecting lens 1 and each short-distance light projecting element 7. Each cover 161a is disposed behind the cover 161b. The light projecting lens 1, each light receiving lens 3, and each short distance light projecting element 7 in the vicinity of the rear of the covers 161 a and 161 b have substantially the same distance in the front-rear direction between the front surface and the covers 161 a and 161 b. It is arranged to become. That is, each light receiving lens 3 is arranged behind the light projecting lens 1 and each short distance light projecting element 7.

また、センサボディ１６内で基板５に実装されている仕切り１６２は、前端がカバー１６１ｂと当接するように前後方向に形成されており、仕切り１６３は、前端がカバー１６１ａ、１６１ｂの両者に当接するように前後方向に形成されている。ここで、各仕切り１６３の前端部１６３ａは、カバー１６１の段部１６１ｃの形状に合わせて、前端部１６３ａが略Ｌ字状となる段部１６３ｂが形成されている。 The partition 162 mounted on the substrate 5 in the sensor body 16 is formed in the front-rear direction so that the front end contacts the cover 161b, and the front end of the partition 163 contacts both the covers 161a and 161b. Is formed in the front-rear direction. Here, the front end portion 163a of each partition 163 is formed with a step portion 163b in which the front end portion 163a is substantially L-shaped in accordance with the shape of the step portion 161c of the cover 161.

そして、センサボディ１６の側面１６４において、受光側の側面１６４ａの前端と、各仕切り１６３の段部１６３ｂの後段との間に、カバー１６１ａが覆設されている。また、各仕切り１６３の段部１６３ｂの前段の間に、カバー１６１ｂが覆設されている。 Then, on the side surface 164 of the sensor body 16, a cover 161 a is provided between the front end of the light receiving side surface 164 a and the rear stage of the step portion 163 b of each partition 163. Further, a cover 161b is provided between the front part of the step part 163b of each partition 163.

上記の構成からなる本実施形態は、実施形態１と同様に、検出物体が遠距離範囲ＬＬ１にある場合、遠距離用投光素子２から射出された光が投光レンズ１で集光された後、前方に射出されて検出物体で反射して、反射光が各受光レンズ３で集光された後、各受光素子４の受光面内に照射され、受光した光に応じて電気信号に変換され、検出物体の有無または検出物体の距離などを検出信号として出力する。また、検出物体が近距離範囲ＬＬ２にある場合、各近距離用投光素子７から射出された光が検出物体で反射して、反射光が各受光レンズ３で集光された後、受光素子４の受光面内に照射され、受光した光に応じて電気信号に変換され、検出物体の有無または検出物体の距離などを検出信号として出力する。 In the present embodiment configured as described above, similarly to the first embodiment, when the detection object is in the long distance range LL1, the light emitted from the long distance light projecting element 2 is condensed by the light projecting lens 1. After that, the light is emitted forward, reflected by the detection object, and the reflected light is collected by each light receiving lens 3 and then irradiated on the light receiving surface of each light receiving element 4 and converted into an electric signal according to the received light. Then, the presence / absence of the detection object or the distance of the detection object is output as a detection signal. When the detection object is in the short distance range LL2, the light emitted from each short distance light projecting element 7 is reflected by the detection object, and the reflected light is condensed by each light receiving lens 3, and then the light receiving element. 4 is irradiated into the light receiving surface and converted into an electrical signal according to the received light, and the presence or absence of the detection object or the distance of the detection object is output as a detection signal.

ここで、遠距離用投光素子２で検出可能な遠距離範囲ＬＬ１および、各近距離用投光素子７で検出可能な近距離範囲ＬＬ２は、図７で示した従来の反射型光電センサの遠距離用投光素子２で検出可能な遠距離範囲Ｌａおよび、近距離用投光素子７で検出可能な近距離範囲Ｌｂよりも後方に広い範囲（ＬＬ１＞Ｌａ、ＬＬ２＞Ｌｂ）となっている。これは、各受光レンズ３の位置を従来よりも後方に配置することによって、各仕切り１６３の前端部１６３ａに段部１６３ｂを形成することができる。そして、この段部１６３ｂによって、従来の反射型光電センサでは、近接距離Ｌｃにある検出物体からの反射光を仕切り２６３の前端部２６３ａによって遮光していた部位（図７参照）に、図２に示す一対の空間１６３ｃが生じる。 Here, the long distance range LL1 that can be detected by the long distance light projecting element 2 and the short distance range LL2 that can be detected by each short distance light projecting element 7 are the same as those of the conventional reflective photoelectric sensor shown in FIG. The long distance range La that can be detected by the long distance light projecting element 2 and the wide range behind the short distance range Lb that can be detected by the short distance light projecting element 7 (LL1> La, LL2> Lb). Yes. This is because the stepped portion 163b can be formed at the front end portion 163a of each partition 163 by disposing the positions of the respective light receiving lenses 3 behind the conventional one. Then, in the conventional reflection type photoelectric sensor, the reflected light from the detection object at the close distance Lc is shielded by the front end portion 263a of the partition 263 (see FIG. 7) by this step portion 163b, as shown in FIG. A pair of spaces 163c shown are created.

したがって、従来の反射型光電センサの近距離範囲Ｌｂよりセンサに近い距離にある、近距離範囲ＬＬ２の後端に検出物体が存在する場合の反射光Ｂ１は、各空間１６３ｃを通過して、受光レンズ３に入射することができる。 Accordingly, the reflected light B1 when the detection object is present at the rear end of the short distance range LL2, which is closer to the sensor than the short distance range Lb of the conventional reflective photoelectric sensor, passes through each space 163c and is received. The light can enter the lens 3.

このように、反射光が空間１６３ｃを通過することによって、各受光レンズ３に反射光が入射する角度が拡大するため、各近距離用投光素子７で検出可能な近距離範囲ＬＬ２は後方に拡大され、不感帯である近接距離をＬＬ３まで縮小される。この不感帯ＬＬ３は、図７で示した従来の反射型光電センサの不感帯Ｌｃよりも、縮小（ＬＬ３＜Ｌｃ）されている。 In this way, since the reflected light passes through the space 163c, the angle at which the reflected light is incident on each light receiving lens 3 is expanded, so that the short distance range LL2 that can be detected by each short distance light projecting element 7 is rearward. It is enlarged and the proximity distance which is a dead zone is reduced to LL3. This dead zone LL3 is reduced (LL3 <Lc) from the dead zone Lc of the conventional reflective photoelectric sensor shown in FIG.

また、近距離用投光素子７を二個と、受光レンズ３および受光素子４の組みを二組備えることによって、近距離範囲ＬＬ２における横方向の検出可能領域を拡大することができ、安定して検出物体を検出することが可能となる。 Further, by providing two short-range light projecting elements 7 and two sets of the light-receiving lens 3 and the light-receiving element 4, the laterally detectable region in the short-range range LL2 can be expanded and stabilized. Thus, it becomes possible to detect the detected object.

また、投光レンズ１と投光素子２の離間距離は従来の反射型光電センサと変えていないため、遠距離範囲ＬＬ１にある検出物体の検出分解能が低下することはない。 Further, since the separation distance between the light projecting lens 1 and the light projecting element 2 is not changed from that of the conventional reflective photoelectric sensor, the detection resolution of the detection object in the long distance range LL1 does not decrease.

１投光レンズ
２遠距離用投光素子
３受光レンズ
４受光素子
５基板
６センサボディ
７近距離用投光素子
６１カバー
６２仕切り
６３仕切り
６３ｂ段部
６３ｃ空間 DESCRIPTION OF SYMBOLS 1 Light projection lens 2 Long distance light projecting element 3 Light receiving lens 4 Light receiving element 5 Board | substrate 6 Sensor body 7 Short distance light projecting element 61 Cover 62 Partition 63 Partition 63b Step part 63c Space

Claims

A light projecting lens; a long distance light projecting element that emits light forward through the light projecting lens; a light receiving lens; a light receiving element that receives light incident from the front through the light receiving lens; A short-distance light projecting element that emits light is provided in the sensor body,
When the distance between the detection target located in front and the front surface of the projection lens is in a long distance range outside the predetermined distance, the light emitted from the long distance light projecting element is reflected by the detection target within the long distance range. If the distance between the detection target located in front of the light receiving element and the front surface of the light projecting lens and the front surface of the short distance light projecting element is within a predetermined distance range, The light emitted from the light projecting element for the distance is reflected by the detection target within the short distance range and irradiated outside the light receiving surface of the light receiving element, and the light emitted from the light projecting element for the short distance is within the short distance range. A long distance light projecting element is arranged at the focal point on the rear side of the light projecting lens so that the light is reflected by the detection target in the light receiving region and irradiated within the light receiving range of the light receiving element, and the light receiving element is arranged at the rear focal point of the light receiving lens. A combination of a light projecting lens and a long distance light projecting element, a light receiving lens and a light receiving element. Sets and are spaced apart, the reflective photoelectric sensor provided is short-range light emitting element therebetween,
The focal length on the rear side of the light receiving lens is shorter than the focal length on the rear side of the light projecting lens, and the front surface of the light receiving lens is arranged behind the front surface of the light projecting lens and the front surface of the short distance light projecting element. A reflective photoelectric sensor, wherein the front surface of the sensor body is formed behind the front surface of the sensor body in front of the light projecting lens and the short distance light projecting element.

Two short-range light projecting elements, one set of the light projecting lens and the long distance light projecting element, and two sets of the light receiving lens and the light receiving element,
A combination of a light projecting lens and a long distance light projecting element is disposed between each pair of the light receiving lens and the light receiving element. One short distance light projecting element is disposed between the light projecting lens and the long distance light projecting element and the other pair of the light receiving lens and the light receiving element. The reflective photoelectric sensor according to claim 1, wherein: