JP3297968B2 - Limited reflection type photoelectric sensor - Google Patents
Limited reflection type photoelectric sensorInfo
- Publication number
- JP3297968B2 JP3297968B2 JP24697594A JP24697594A JP3297968B2 JP 3297968 B2 JP3297968 B2 JP 3297968B2 JP 24697594 A JP24697594 A JP 24697594A JP 24697594 A JP24697594 A JP 24697594A JP 3297968 B2 JP3297968 B2 JP 3297968B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- receiving
- photoelectric sensor
- unit
- lens
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
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- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
- Geophysics And Detection Of Objects (AREA)
- Switches Operated By Changes In Physical Conditions (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は物体の検知領域を限定す
るようにした限定反射型の光電センサに関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a limited reflection type photoelectric sensor which limits an object detection area.
【０００２】[0002]
【従来の技術】従来投光部より光ビームを物体検知領域
に向けて照射し、これと交差する特定範囲の光を受光す
る受光部を設け、この交差領域を検知領域として物体が
この領域を通過したときには、受光部に得られる反射光
を検出して物体を判別するようにした限定反射型光電セ
ンサが用いられている。図１１（ａ）は従来の限定反射
型光電センサ１００の構成を示す概略図である。投光回
路１０１は投光素子１０２を駆動するものであって、投
光素子１０２の焦点位置に投光レンズ１０３が設けられ
る。そしてこの投光軸に交差するように一定の受光範囲
を持つ受光レンズ１０４，受光素子１０５を配置する。
１０６は受光素子１０５の出力を処理する受光回路であ
る。さて図１１（ｂ）はこの光電センサ１００からの距
離Ｌ１〜Ｌ５の位置での、投光ビームと受光ビームとの
関係を示す図である。本図に示すように距離Ｌ２〜Ｌ４
の範囲では、ハッチングを付して示す投光ビームと受光
ビームとが接し、又は重なり合い、この範囲外では離れ
ている。従ってＬ２〜Ｌ４の範囲が動作領域となる。こ
のように図１１（ａ）に斜線で示す動作領域に物体が到
来する場合には、受光素子１０５に信号が得られるた
め、この信号に基づいて物体の有無を判別している。限
定反射型光電センサは投光ビームと受光ビームとが夫々
広がりを有していない場合には、物体を検知して検知信
号を出力する動作レベルと、物体が移動して非検知状態
となる復帰レベルとの距離の差（以下応差という）が小
さく、又背景の影響も少なくなる。更に投受光部の光軸
の角度を変化させることによって、検出距離の設定が可
能であるという特徴がある。2. Description of the Related Art Conventionally, a light beam is radiated from a light projecting section toward an object detection area, and a light receiving section for receiving light in a specific range intersecting the light beam is provided. When the light passes through, a limited reflection type photoelectric sensor is used which detects reflected light obtained by a light receiving unit to determine an object. FIG. 11A is a schematic diagram showing a configuration of a conventional limited reflection type photoelectric sensor 100. The light projecting circuit 101 drives the light projecting element 102, and a light projecting lens 103 is provided at a focal position of the light projecting element 102. Then, a light receiving lens 104 and a light receiving element 105 having a fixed light receiving range are arranged so as to intersect the light projecting axis.
Reference numeral 106 denotes a light receiving circuit that processes the output of the light receiving element 105. FIG. 11B is a diagram showing the relationship between the light projecting beam and the light receiving beam at positions L1 to L5 from the photoelectric sensor 100. As shown in the figure, distances L2 to L4
In the range, the projected light beam and the received light beam indicated by hatching are in contact with or overlap with each other, and are separated outside this range. Therefore, the range of L2 to L4 is the operation area. As described above, when an object arrives at the operation area indicated by oblique lines in FIG. 11A, a signal is obtained from the light receiving element 105, and the presence or absence of the object is determined based on the signal. The limited-reflection type photoelectric sensor detects an object and outputs a detection signal when the projected beam and the received beam do not have a spread. The difference in distance from the level (hereinafter referred to as hysteresis) is small, and the influence of the background is reduced. Further, there is a feature that the detection distance can be set by changing the angle of the optical axis of the light emitting and receiving unit.
【０００３】[0003]
【発明が解決しようとする課題】このような従来の限定
反射型光電センサ１００は、図１２（ａ）に示すように
近づいてくる検出物体１１０を検出して一定の位置で停
止させるために用いたり、例えばプリント基板１１１等
の上部に実装されている小さい電子部品１１２等の検出
物体をプリント基板１１１と分離して検出するような用
途に用いられる。このため図１１（ｂ）に示す動作領域
のうち、特に光電センサより離れた位置（距離Ｌ４）で
の投受光ビームをシャープにする必要がある。即ち受光
出力と距離との特性は特に距離の遠い側で急峻な特性に
する必要がある。Such a conventional limited reflection type photoelectric sensor 100 is used for detecting an approaching detection object 110 and stopping it at a predetermined position as shown in FIG. For example, it is used for a purpose of detecting a detection object such as a small electronic component 112 mounted on an upper portion of the printed board 111 or the like separately from the printed board 111 . Therefore, in the operation area shown in FIG. 11B, it is necessary to sharpen the light projection / reception beam particularly at a position (distance L4) apart from the photoelectric sensor. That is, it is necessary to make the characteristic between the light receiving output and the distance sharp, especially on the far side of the distance.
【０００４】図１３は投受光部に光ファイバを用いた限
定反射型光電センサの光学系部分のみを拡大して示す図
である。本図に示すように従来の光電センサでは、光フ
ァイバの発光部及び受光部の光軸と投受光レンズの光軸
を一致させるように配置している。そして光ファイバは
一定の直径を有しているため、発光部及び受光部の周辺
部分は投受光レンズ１０３，１０４の光軸以外のところ
に位置することとなる。レンズは非球面レンズを用いた
場合に球面収差は除去できるが、コマ収差（光軸外の点
から発した光線に対する収差）は完全には除去すること
はできない。図３の曲線Ａはこの光ファイバを用いた光
電センサの距離に対する受光出力の変化を示すグラフで
ある。又図４（ａ）は距離Ｌ４における投受光ビームを
示す図である。そのため図３に示すように投光スポット
と受光エリアとは特に光電センサの検知領域の光電セン
サより離れた側では図示のように広がってしまう。これ
らの図に示すように光束が広がれば光束密度が低くなる
ため、物体検知の感度が低下し、検出点において急峻で
なくなる。又この感度が低い領域では応差の距離が大き
くなってしまうという欠点があった。FIG. 13 is an enlarged view showing only an optical system portion of a limited reflection type photoelectric sensor using an optical fiber for a light emitting / receiving section. As shown in this figure, in the conventional photoelectric sensor, the optical axes of the light emitting unit and the light receiving unit of the optical fiber and the optical axis of the light projecting and receiving lens are aligned. Since the optical fiber has a constant diameter, the peripheral portions of the light emitting portion and the light receiving portion are located at positions other than the optical axes of the light emitting and receiving lenses 103 and 104. When an aspherical lens is used, spherical aberration can be removed, but coma (point off the optical axis)
Aberration) for light emitted from completely it can not be removed. A curve A in FIG. 3 is a graph showing a change in the light receiving output with respect to the distance of the photoelectric sensor using the optical fiber. FIG. 4 (a) is a diagram showing the projected and received beams at the distance L4. Therefore, as shown in FIG. 3, the light projecting spot and the light receiving area spread as shown in the drawing particularly on the side of the detection area of the photoelectric sensor that is farther from the photoelectric sensor. As shown in these figures, if the luminous flux spreads, the luminous flux density decreases, so that the sensitivity of object detection is reduced and the detection point is not sharp. Further, there is a disadvantage that the distance of the hysteresis increases in the region where the sensitivity is low.
【０００５】本発明はこのような従来の問題点に鑑みて
なされたものであって、通常の投受光素子を用いて、特
に遠距離側の動作領域において投受光ビームの光束を鋭
くし、動作領域を限定できるようにすることを技術的課
題とする。SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and uses an ordinary light emitting / receiving element to sharpen a light beam of a light emitting / receiving beam particularly in an operation region on a long distance side to operate. It is a technical task to be able to limit an area.
【０００６】[0006]
【課題を解決するための手段】本願の請求項１の発明
は、投光部の投光ビームと受光部の受光ビームとを所定
角度で交差させ、交差する測定領域の物体からの反射光
を受光部により受光し、その受光レベルに基づいて物体
の有無を判別する限定反射型光電センサであって、投光
部は、投光ビームを集束する投光レンズを有するもので
あり、該投光レンズの光軸に投光部の発光手段の端部を
一致させるように配置し、受光部は受光ビームを集束す
る受光レンズを有するものであり、該受光レンズの光軸
に受光部の受光手段の受光端部を一致させるように配置
し、投光レンズの光軸に一致して配置された投光部の発
光手段の端部が投光レンズによって結像される位置と、
受光レンズの光軸に一致して配置された受光部の受光手
段の受光端部が受光レンズによって結像される位置とを
一致させるように配置したことを特徴とするものであ
る。According to the first aspect of the present invention, a light beam of a light projecting portion and a light receiving beam of a light receiving portion intersect at a predetermined angle, and reflected light from an object in an intersecting measurement region is formed. A limited reflection type photoelectric sensor that receives light by a light receiving unit and determines the presence or absence of an object based on the light receiving level, wherein the light projecting unit has a light projecting lens that focuses a light projecting beam. The light-receiving unit is arranged so that the end of the light-emitting unit of the light-projecting unit is aligned with the optical axis of the lens, and the light-receiving unit has a light-receiving lens that focuses the light-receiving beam. So that the light-receiving ends of the
Of the light-emitting part, which is arranged in line with the optical axis of the light-emitting lens.
The position where the end of the light means is imaged by the projection lens,
The light-receiving part of the light-receiving part, which is arranged in line with the optical axis of the light-receiving lens
The position where the light receiving end of the step is imaged by the light receiving lens
It is characterized by being arranged so as to match .
【０００７】本願の請求項２の発明では、投光部及び受
光部は、その発光手段及び受光手段の端部を遮蔽板によ
って形成したことを特徴とするものである。In the invention of claim 2 of the present application, the light projecting unit and the light receiving unit are characterized in that the light emitting means and the light receiving means are formed at their ends with a shielding plate.
【０００８】本願の請求項３の発明では、投光部は投光
レンズの焦点位置に投光用遮光板を配置し、受光部は受
光レンズの焦点位置に受光側遮蔽板を配置したことを特
徴とするものである。According to the invention of claim 3 of the present application, the light projecting unit arranges the light shielding plate at the focal position of the light projecting lens, and the light receiving unit arranges the light receiving side shielding plate at the focal position of the light receiving lens. It is a feature.
【０００９】本願の請求項４の発明では、投光部及び受
光部は光ファイバを用いたことを特徴とするものであ
る。According to a fourth aspect of the present invention, the light projecting unit and the light receiving unit use optical fibers.
【００１０】[0010]
【作用】このような特徴を有する本発明によれば、投光
部と受光部の光束を交差させてその交差領域を物体検知
領域としており、投受光ビームを集束する集光レンズの
光軸に投光部の発光手段の端部を一致させ、受光ビーム
の受光側集光レンズの光軸に受光手段の受光端部を一致
させるように配置している。こうすれば動作領域の最遠
点での光束の広がりがなくなり、光束密度の高い部分の
みを物体検知領域として限定できることとなる。SUMMARY OF According to this invention having such a feature, and then the crossing region and the object detecting area by intersecting the light beam between the light receiving portion projecting part, the optical axis of the condenser lens for focusing the light emitting and receiving beams Are arranged so that the end of the light emitting means of the light projecting section coincides with the light receiving end of the light receiving means and the optical axis of the light receiving side condenser lens of the light receiving beam. In this way, the spread of the light beam at the farthest point of the operation area is eliminated, and only the portion having a high light beam density can be limited as the object detection area.
【００１１】[0011]
【実施例】図１は本発明による限定反射型光電センサの
投受光部の光学系の基本的な構成を示す概略図である。
本図において投光部は投光回路１と投光素子２が設けら
れ、投光レンズ３を有することは従来例と同様である。
本実施例では投光レンズ３の光軸３Ｌに対して投光素子
の投光チップ２ａの端部を一致させるように配置してい
る。即ち投光部の光を出射する発光手段の端部を投光軸
３Ｌに一致させるようにしている。同様にして受光側も
受光レンズ４の受光軸４Ｌに対して受光素子５の受光チ
ップ５ａの端部を一致させるように配置する。そして投
光素子２，受光素子５は図１に示すように互いに外向き
にその端部を一致させるように配置しておくものとす
る。FIG. 1 is a schematic diagram showing a basic configuration of an optical system of a light emitting / receiving section of a limited reflection type photoelectric sensor according to the present invention.
In the drawing, the light projecting unit is provided with a light projecting circuit 1 and a light projecting element 2 and has a light projecting lens 3 as in the conventional example.
In this embodiment, the light projecting chip 2a is arranged so that the end of the light projecting chip 2a of the light projecting element coincides with the optical axis 3L of the light projecting lens 3. That is, the end of the light emitting unit that emits light from the light projecting unit is made to coincide with the light projecting axis 3L. Similarly, the light receiving side is arranged such that the end of the light receiving chip 5a of the light receiving element 5 coincides with the light receiving axis 4L of the light receiving lens 4. The light emitting element 2 and the light receiving element 5 are arranged so that their ends are outwardly aligned with each other as shown in FIG.
【００１２】図２は本発明の第１実施例による限定反射
型光電センサの光学系部分を示す図である。本実施例は
光ファイバを用いた光電センサを示している。本実施例
では前述したように投光レンズ３の光軸にその端部を一
致させるように投光用の光ファイバ１１を配置する。そ
して受光側の受光レンズ４の受光軸に端部を一致させる
よう受光用の光ファイバ１２を配置したものである。こ
うすれば図示のように投光ビームと受光ビームの交差す
る動作領域のうち、光電センサより遠い側の点で従来例
による光電センサに比べて像のぼけがなくなる。従って
受光出力と距離特性は、図３の曲線Ｂに示すように曲線
Ａに比べて急峻なものとすることができる。又図２にお
いて、動作領域の最遠点の距離Ｌ４での投受光ビームは
図４（ｂ）に示すものとなり、２つの円の接する部分の
ぼけがなくなる。FIG. 2 is a view showing an optical system portion of the limited reflection type photoelectric sensor according to the first embodiment of the present invention. This embodiment shows a photoelectric sensor using an optical fiber. In the present embodiment, as described above, the optical fiber 11 for projecting light is arranged so that the end of the projecting lens 3 coincides with the optical axis. The light receiving optical fiber 12 is arranged so that the end of the light receiving lens 4 coincides with the light receiving axis of the light receiving lens 4 on the light receiving side. In this way, as shown in the drawing, in the operation area where the projected beam and the received beam intersect, a point farther from the photoelectric sensor does not cause image blur compared with the conventional photoelectric sensor. Therefore, the light receiving output and the distance characteristic can be steeper than the curve A as shown by the curve B in FIG. Further, in FIG. 2, the projected / received beam at the distance L4 of the farthest point in the operation area is as shown in FIG. 4B, and the blur of the contact portion between the two circles is eliminated.
【００１３】図５はこの限定反射型光電センサの投受光
用ファイバに接続される光電センサ本体の構成を示すブ
ロック図である。本図に示すように本実施例では周期的
に投光パルスを発生する投光回路１を有しており、その
出力は投光素子２に与えられる。投光素子２の前面には
投光用光ファイバ１１の端面が固定されており、発光し
た光を光ファイバ１１に入射するものである。又受光用
光ファイバ１２より得られる光は受光素子５、例えばフ
ォトダイオードに入射される。受光素子５は受光した光
信号を電気信号に変換するものであって、その出力は受
光回路６に与えられる。受光回路６は図示のように受光
信号を増幅する増幅器１３，ゲート回路１４を有してい
る。ゲート回路１４の他方の入力端には投光回路１より
投光パルスが入力され、投光パルスに同期した受光信号
のみが比較回路１５に与えられる。比較回路１５は所定
の閾値と受光レベルとを比較するものであって、受光レ
ベルが閾値を越えるときには比較出力を信号処理部１６
に与える。信号処理部１６は連続して複数のクロック周
期の間受光信号が得られるときに物体を検知し、出力回
路１７を介して物体検知信号を外部に出力するものであ
る。FIG. 5 is a block diagram showing a configuration of a photoelectric sensor main body connected to the light emitting / receiving fiber of the limited reflection type photoelectric sensor. As shown in the figure, the present embodiment has a light projecting circuit 1 that periodically generates a light projecting pulse, and its output is given to a light projecting element 2. An end face of the light projecting optical fiber 11 is fixed to the front surface of the light projecting element 2, and the emitted light enters the optical fiber 11. Light obtained from the light receiving optical fiber 12 is incident on a light receiving element 5, for example, a photodiode. The light receiving element 5 converts a received light signal into an electric signal, and its output is given to a light receiving circuit 6. The light receiving circuit 6 has an amplifier 13 for amplifying a light receiving signal and a gate circuit 14 as shown in the figure. A light emission pulse is input from the light emission circuit 1 to the other input terminal of the gate circuit 14, and only a light reception signal synchronized with the light emission pulse is supplied to the comparison circuit 15. The comparison circuit 15 compares a predetermined threshold value with the light reception level. When the light reception level exceeds the threshold value, the comparison circuit 15 outputs a comparison output to the signal processing unit 16.
Give to. The signal processing unit 16 detects an object when a light receiving signal is continuously obtained for a plurality of clock cycles, and outputs an object detection signal to the outside via an output circuit 17.
【００１４】図６は本発明の第２実施例による限定反射
型光電センサの光学系部分を示す概略図である。本実施
例では投光用ファイバ１１と受光用ファイバ１２を有し
ており、その端面に夫々投光軸３Ｌ及び受光軸４Ｌに達
する位置までの遮蔽板２１，２２を設けたものである。
即ち本実施例では、これらの遮蔽板２１，２２は図示の
ように投受光ビームの光軸で形成される面（紙面）に垂
直に、投光用光ファイバ１１より出射される光ビームの
一部を遮蔽するナイフエッジ型の投光用遮蔽板２１を受
光用光ファイバ１２の端面側よりコアの端面に接して取
付ける。同様にしてナイフエッジ型の受光用遮蔽板２２
はこれと対称な位置、即ち投光用光ファイバ１１の端面
側より受光用光ファイバ１２の端面に接して紙面に垂直
にその受光ビームの一部を遮蔽するように取付ける。こ
れらの遮蔽板２１，２２の端部は図示のように投受光軸
３Ｌ，４Ｌと一致させておくものとする。FIG. 6 is a schematic view showing an optical system of a limited reflection type photoelectric sensor according to a second embodiment of the present invention. In this embodiment, a light projecting fiber 11 and a light receiving fiber 12 are provided, and shield plates 21 and 22 are provided on the end surfaces to reach the light projecting axis 3L and the light receiving axis 4L, respectively.
That is, in the present embodiment, these shielding plates 21 and 22 are arranged so that one of the light beams emitted from the light projecting optical fiber 11 is perpendicular to the surface (paper surface) formed by the optical axes of the light projecting and receiving beams as shown in FIG. A light-shielding plate 21 of a knife edge type for shielding the portion is attached from the end face side of the optical fiber 12 for light reception to the end face of the core. Similarly, the light receiving shielding plate 22 of the knife edge type
Is mounted in a symmetrical position, that is, in contact with the end face of the light receiving optical fiber 12 from the end face side of the light projecting optical fiber 11 so as to shield a part of the light receiving beam perpendicularly to the paper surface. Assume that the ends of these shielding plates 21 and 22 are aligned with the light emitting and receiving axes 3L and 4L as shown in the figure.
【００１５】図７は投光部の光ファイバ１１とレンズ６
の関係、及び光ビームを示す図である。図７（ａ）にお
いて光ファイバ１１のコアの中心部分より出射される光
を１１Ａ、コア１１ａの端部より出射される光を１１Ｂ
としている。本図より明らかなように、光ファイバ１１
のコアの中心部分より出射される光はレンズ３の焦点位
置Ｐ０で集光することとなり、又コア１１ａの下端部よ
り出射した光１１Ｂは焦点位置Ｐ０より上方の位置Ｐ１
で集束することとなる。受光側の受光範囲についても同
様である。尚図７では光ファイバ１１から出射される光
の中心と両端の光の分布のみを示しているが、この間で
は光が連続して出射されることはいうまでもない。FIG. 7 shows the optical fiber 11 and the lens 6 of the light projecting section.
FIG. 4 is a diagram showing the relationship of the above and a light beam. In FIG. 7A, the light emitted from the central portion of the core of the optical fiber 11 is 11A, and the light emitted from the end of the core 11a is 11B.
And As is apparent from FIG.
The light emitted from the central portion of the core is focused at the focal position P0 of the lens 3, and the light 11B emitted from the lower end of the core 11a is focused at the position P1 above the focal position P0.
Will be focused. The same applies to the light receiving range on the light receiving side. Although FIG. 7 shows only the distribution of light at the center and both ends of the light emitted from the optical fiber 11, it goes without saying that light is continuously emitted during this period.
【００１６】又図７（ｂ）は投光用光ファイバ１１の端
面から見た投光レンズ３と遮蔽板２１の関係を示す図で
ある。本図に示すように長方形状の遮蔽板２１により投
光レンズ３の１／２を受光用光ファイバ１２側から遮蔽
するように構成している。こうすれば投光ビームや受光
ビームは図４（ｃ）に示すように検出点において像のぼ
けがなく、且つ線状に投受光ビームが重なり合うように
なる。従って受光出力−距離特性は図３の曲線Ｃに示す
ように更に急峻にすることができる。FIG. 7B is a view showing the relationship between the light projecting lens 3 and the shielding plate 21 as viewed from the end surface of the light projecting optical fiber 11. As shown in the drawing, a half of the light projecting lens 3 is shielded from the light receiving optical fiber 12 side by a rectangular shielding plate 21. In this way, the projected light beam and the received light beam have no image blur at the detection point as shown in FIG. 4C, and the projected and received light beams are overlapped linearly. Therefore, the light receiving output-distance characteristic can be further sharpened as shown by the curve C in FIG.
【００１７】図８は本発明の第３実施例による限定反射
型光電センサの光学系部分を示す概略図である。本実施
例では投受光用光ファイバ１１，１２の端面は、図６に
示す第２実施例に比べて最遠点の検出点に対応した結像
位置より離れて後ろ側に配置している。そして遮蔽板２
１，２２は検出点に対応した結像位置に配置しておく。
こうすれば第２実施例と同様の効果を得ることができ
る。投光部や受光部又はその投受光素子を遮蔽板２１，
２２の近傍に配置することができない場合には、このよ
うな配置が有効となる。このときの受光出力−距離特性
は図３の曲線Ｄに示すものとなり、投光ビームと受光ビ
ームのぼけ具合は図４（ｄ）に示すものとなる。FIG. 8 is a schematic view showing an optical system of a limited reflection type photoelectric sensor according to a third embodiment of the present invention. In the present embodiment, the end faces of the optical fibers 11 and 12 for projecting and receiving light are arranged behind and behind the imaging position corresponding to the farthest detection point as compared with the second embodiment shown in FIG. And shielding plate 2
Reference numerals 1 and 22 are arranged at image forming positions corresponding to the detection points.
In this case, the same effect as in the second embodiment can be obtained. The light emitting unit and the light receiving unit or the light emitting and receiving elements are
In the case where it is not possible to arrange in the vicinity of 22, such an arrangement is effective. The light-receiving output-distance characteristic at this time is as shown by a curve D in FIG. 3, and the degree of blur between the projected light beam and the received light beam is as shown in FIG.
【００１８】次に光電センサのケース前方に固定され、
投受光用光ビームの方向を側方に向けるサイドビューア
タッチメントについて説明する。図９はこのサイドビュ
ーアタッチメントの構成を示す正面図及び側面図であ
る。本図においてアタッチメント３１は略コ字状の部材
であって、両側に互いに内向きの爪３２ａ，３３ａを持
ったアーム３２，３３が設けられる。そしてアーム３
２，３３の間は三角柱状の部分３４が形成されている。
このサイドビューアタッチメント３１はポリカーボネイ
ト等の透明性樹脂で形成され、レンズ３より出射した投
光ビームをその表面３４ａで全反射することによって投
光ビームの方向を直角に折り曲げるものであり、同様に
して受光ビームは三角柱部３４の表面で全反射する。Next, the photoelectric sensor is fixed in front of the case,
A side viewer attachment for directing the direction of the light projecting / receiving light beam to the side will be described. FIG. 9 is a front view and a side view showing the configuration of the side viewer attachment. In this drawing, the attachment 31 is a substantially U-shaped member, and provided with arms 32, 33 having claws 32a, 33a facing each other on both sides. And arm 3
A triangular prism-shaped portion 34 is formed between 2 and 33.
The side viewer attachment 31 is formed of a transparent resin such as polycarbonate, and totally reflects the light beam emitted from the lens 3 on its surface 34a to bend the direction of the light beam at a right angle. The received light beam is totally reflected on the surface of the triangular prism portion 34.
【００１９】図１０はこのアタッチメントが取付けられ
る光電センサのケース１０の外観を示す正面図及び側面
図である。又ケース１０は図１０（ａ）に示すように側
方に爪３２ａ，３３ａ及びアーム３２，３３と係合する
凹部４１ａ，４１ｂが設けられる。この凹部４１ａ，４
１ｂにサイドビューアタッチメント３１のアームを係合
させた状態を図１０（ｂ）に示している。こうすれば投
受光ビームの光軸はいずれも直角に折り曲げられるた
め、ケース１０の側方に検知領域を設けることができ
る。更に透明性樹脂内を光が通過するため、光行路が長
くなり検知領域をより遠ざけることができる。又ポリカ
ーボネイトに代えて、三角柱状の部分を除きその表面３
４ａ部分のみの平板状の部材で構成して、その表面に蒸
着等によって反射膜を成形するようにしてもよい。この
場合には光行路を長くする効果はないが、側方を検知領
域とすることができる。FIG. 10 is a front view and a side view showing the appearance of the case 10 of the photoelectric sensor to which the attachment is attached. As shown in FIG. 10A, the case 10 is provided with concave portions 41a and 41b which engage with the claws 32a and 33a and the arms 32 and 33 on the side. These recesses 41a, 4
FIG. 10B shows a state in which the arm of the side viewer attachment 31 is engaged with 1b. In this case, the optical axis of each of the projected and received beams can be bent at a right angle, so that a detection area can be provided on the side of the case 10. Further, since the light passes through the transparent resin, the optical path becomes longer and the detection area can be further distant. Also, instead of polycarbonate, the surface 3
The reflection film may be formed by vapor deposition or the like on the surface of a plate-shaped member having only the portion 4a. In this case, there is no effect of lengthening the optical path, but the side can be used as the detection area.
【００２０】[0020]
【発明の効果】以上詳細に説明したように本発明によれ
ば、投受光ビームの光束が物体の検知領域の最遠点側で
光束密度が高くなる。このため物体の移動に伴う応差を
小さくすることができ、物体の検知を確実に行うことが
できるという効果が得られる。従って検出物体の反射率
や表面状態の影響を受けずに同一位置で出力を得ること
ができるため、位置決め精度を向上させることができ
る。又応差の距離が小さいため、小さい段差や背景上の
微小な部品の検出が可能になるという効果も得られる。As described above in detail, according to the present invention, the luminous flux of the projected / received beam has a high luminous flux density at the farthest point side of the detection area of the object. For this reason, the hysteresis accompanying the movement of the object can be reduced, and the effect of reliably detecting the object can be obtained. Therefore, an output can be obtained at the same position without being affected by the reflectance or the surface state of the detection object, so that the positioning accuracy can be improved. Further, since the distance of the hysteresis is small, an effect that a small step and a minute component on the background can be detected can be obtained.
【図１】本発明による限定反射型光電センサの光学系部
分の基本構成を示す概略図である。FIG. 1 is a schematic diagram showing a basic configuration of an optical system portion of a limited reflection type photoelectric sensor according to the present invention.
【図２】本発明の第１実施例による限定反射型光電セン
サの光学系部分を示す概略図である。FIG. 2 is a schematic view showing an optical system portion of the limited reflection type photoelectric sensor according to the first embodiment of the present invention.
【図３】本発明の受光出力と距離との特性を示すグラフ
である。FIG. 3 is a graph showing characteristics of a light receiving output and a distance according to the present invention.
【図４】測定領域の最遠点での投受光ビームを示す図で
ある。FIG. 4 is a diagram showing a light emitting and receiving beam at a farthest point of a measurement area.
【図５】本実施例の光電センサの電気的構成を示すブロ
ック図である。FIG. 5 is a block diagram illustrating an electrical configuration of the photoelectric sensor according to the present embodiment.
【図６】本発明の第２実施例による限定反射型光電セン
サの光学系部分を示す概略図である。FIG. 6 is a schematic view showing an optical system part of a limited reflection type photoelectric sensor according to a second embodiment of the present invention.
【図７】本発明の第２実施例による限定反射型光電セン
サの光ファイバの出力及び遮蔽板の関係を示す図であ
る。FIG. 7 is a diagram showing a relationship between an output of an optical fiber and a shield plate of a limited reflection type photoelectric sensor according to a second embodiment of the present invention.
【図８】本発明の第３実施例による限定反射型光電セン
サの光学系部分を示す概略図である。FIG. 8 is a schematic view showing an optical system part of a limited reflection photoelectric sensor according to a third embodiment of the present invention.
【図９】本発明の第２実施例に用いられるサイドビュー
アタッチメントの構成を示す正面図及び側面図である。FIG. 9 is a front view and a side view showing a configuration of a side viewer attachment used in a second embodiment of the present invention.
【図１０】本実施例のサイドビューアタッチメントを取
付けるようにした光電センサの外観を示す正面図及び側
面図である。FIG. 10 is a front view and a side view showing the appearance of a photoelectric sensor to which the side viewer attachment of the present embodiment is attached.
【図１１】従来の限定反射型光電センサの構成を示す概
略図である。FIG. 11 is a schematic view showing a configuration of a conventional limited reflection type photoelectric sensor.
【図１２】限定反射型光電センサの使用状態を示す概略
図である。FIG. 12 is a schematic diagram showing a use state of a limited reflection type photoelectric sensor.
【図１３】従来の限定反射型光電センサの光学系部分を
示す概略図である。FIG. 13 is a schematic view showing an optical system portion of a conventional limited reflection type photoelectric sensor.
１ 投光回路 ２ 投光素子 ２ａ 投光チップ ３ 投光レンズ ４ 受光レンズ ５ 受光素子 ５ａ 受光チップ ６ 受光回路 １１，１２ 光ファイバ ２１，２２ 遮蔽板 ３１ サイドビューアタッチメント REFERENCE SIGNS LIST 1 light emitting circuit 2 light emitting element 2 a light emitting chip 3 light emitting lens 4 light receiving lens 5 light receiving element 5 a light receiving chip 6 light receiving circuit 11, 12 optical fiber 21, 22 shielding plate 31 side viewer attachment
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ Ｇ０１Ｖ 9/04 Ｃ (56)参考文献 特開 平６−229822（ＪＰ，Ａ) 特開 昭55−78267（ＪＰ，Ａ) 実開 平４−94585（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.7，ＤＢ名) G01V 8/12 G01J 1/42 G01V 8/14 G01V 8/16 H01H 35/00 ──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. 7 Identification code FI G01V 9/04 C (56) References JP-A-6-229822 (JP, A) JP-A-55-78267 (JP, A) Actually open Hei 4-94585 (JP, U) (58) Fields investigated (Int. Cl. 7 , DB name) G01V 8/12 G01J 1/42 G01V 8/14 G01V 8/16 H01H 35/00
Claims (4)
ムとを所定角度で交差させ、交差する測定領域の物体か
らの反射光を受光部により受光し、その受光レベルに基
づいて物体の有無を判別する限定反射型光電センサにお
いて、 前記投光部は、投光ビームを集束する投光レンズを有す
るものであり、該投光レンズの光軸に前記投光部の発光
手段の端部を一致させるように配置し、 前記受光部は受光ビームを集束する受光レンズを有する
ものであり、該受光レンズの光軸に前記受光部の受光手
段の受光端部を一致させるように配置し、 前記投光レンズの光軸に一致して配置された前記投光部
の発光手段の端部が前記投光レンズによって結像される
位置と、前記受光レンズの光軸に一致して配置された前
記受光部の受光手段の受光端部が前記受光レンズによっ
て結像される位置とを一致させるように配置した ことを
特徴とする限定反射型光電センサ。1. A light beam of a light projecting unit and a light receiving beam of a light receiving unit intersect at a predetermined angle, and reflected light from an object in an intersecting measurement area is received by a light receiving unit. In the limited reflection type photoelectric sensor that determines the presence or absence of the light emitting device, the light projecting unit has a light projecting lens that converges the light projecting beam, and an end of a light emitting unit of the light projecting unit is provided on an optical axis of the light projecting lens. parts arranged to match the said light receiving portion are those having a light-receiving lens for focusing the light beam, wherein arranged to match the receiving end of the receiving means of the receiving unit in the optical axis of the light receiving lens , The light projecting unit disposed so as to coincide with the optical axis of the light projecting lens
The end of the light emitting means is imaged by the light projecting lens
Position and before being aligned with the optical axis of the receiving lens
The light receiving end of the light receiving means of the light receiving section is
A limited reflection type photoelectric sensor, wherein the limited reflection type photoelectric sensor is arranged so as to coincide with a position where an image is formed .
及び受光手段の端部を遮蔽板によって形成したことを特
徴とする請求項１記載の限定反射型光電センサ。2. The limited-reflection type photoelectric sensor according to claim 1, wherein the light emitting unit and the light receiving unit are formed by shielding a light emitting unit and a light receiving unit with an end portion formed of a shielding plate.
光用遮光板を配置し、前記受光部は受光レンズの焦点位
置に受光側遮蔽板を配置したものであることを特徴とす
る請求項２記載の限定反射型光電センサ。3. The light-emitting unit includes a light-shielding plate disposed at a focal position of a light-projecting lens, and the light-receiving unit includes a light-shielding plate disposed at a focal position of a light-receiving lens. The limited reflection type photoelectric sensor according to claim 2.
いたことを特徴とする請求項１〜３のいずれか１項に記
載の限定反射型光電センサ。4. The limited reflection type photoelectric sensor according to claim 1, wherein the light projecting unit and the light receiving unit use an optical fiber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24697594A JP3297968B2 (en) | 1994-09-14 | 1994-09-14 | Limited reflection type photoelectric sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24697594A JP3297968B2 (en) | 1994-09-14 | 1994-09-14 | Limited reflection type photoelectric sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0886885A JPH0886885A (en) | 1996-04-02 |
| JP3297968B2 true JP3297968B2 (en) | 2002-07-02 |
Family
ID=17156510
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24697594A Expired - Fee Related JP3297968B2 (en) | 1994-09-14 | 1994-09-14 | Limited reflection type photoelectric sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3297968B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013136824A1 (en) | 2012-03-15 | 2013-09-19 | オムロン株式会社 | Reflective photoelectric sensor |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2395262A (en) * | 2002-11-11 | 2004-05-19 | Qinetiq Ltd | Optical proximity sensor with array of spot lights and a mask |
| JP6170713B2 (en) * | 2013-04-12 | 2017-07-26 | パナソニック デバイスＳｕｎｘ株式会社 | Reflective photoelectric sensor |
-
1994
- 1994-09-14 JP JP24697594A patent/JP3297968B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013136824A1 (en) | 2012-03-15 | 2013-09-19 | オムロン株式会社 | Reflective photoelectric sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0886885A (en) | 1996-04-02 |
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