JPS5873888A - Photoelectric switch - Google Patents

Abstract

PURPOSE:To remove the effect of a noise light such as a projection light of another photoelectric switch and thereby to prevent a false operation, by responding only to a reception signal of a noise light falling on a reception element before the generation of a light projection pulse, and thereby delaying the generation of the following light projection pulse. CONSTITUTION:A light projecting unit 1T has a pulse oscillator comprising resistors 14-19, a capacitor 15, diodes 20 and 22 and a comparator 21, and a transistor 13 is connected serially to time constant circuits 14 and 15 to constitute a control circuit together with resistors 11 and 12. An oscillation pulse is led to LED27. A light receiving unit 1R has a wave-shaping circuit comprising a phototransistor 29, resistors 28, 31-34, a capacitor 30 and a comparator 35, converting only a signal having a peak value not lower than a prescribed level into a rectangular wave. This rectangular wave is supplied to integrating circuits 37-40 via a gate 36. The generation of a pulse is stopped temporarily corresponding to a signal of a noise light falling on a light receiving element during a period before the generation of the pulse, and thereby a subsequent pulse is delayed.

Description

【発明の詳細な説明】 （イ）発明の分野 この発明は、パルス変調光形の光電スイッチ、ずなわち
パルス光を投射し、このパルス光に同期した受光イー１
号のみを取り出しく検出動作を行なうようにしたタイ／
の光電スイッチに関し、特に自己のパルス光と周期の似
通った他の光電スイッチのパルス光等の周期性のある雑
音光に対して誤動作りることがないように回路構成を改
善しｒ、：パルス変調光形の光電スイッチに関する。DETAILED DESCRIPTION OF THE INVENTION (A) Field of the Invention The present invention relates to a pulse modulated light type photoelectric switch, that is, a light receiving element 1 that projects pulsed light and that is synchronized with the pulsed light.
A tie/tie that performs a detection operation to extract only the
Regarding the photoelectric switch, the circuit configuration has been improved so that it does not malfunction in response to periodic noise light such as pulse light from other photoelectric switches whose period is similar to that of the photoelectric switch. This invention relates to a modulated light type photoelectric switch.

（ロ）従来技術とイの問題点 パルス変調光形の光電スイッチで゛は、投光パルスに同
期した受光入／Ｊだけを取り出し、その他の期間に入っ
た受光人力は禁１１りる、いわゆる同期ケ−１７５式を
採用しているため、非連続的な雑音光に対しでは誤動作
防＋ｆの効果がある。しかしながら光電スイッチを第１
図（ａ）に示１ように、複数個並置しく使用する場合も
多い１．このような場合、光電スイツチの投光部１−ｒ
’、２Ｔの光の投射範囲及び受光部ＩＲ，２Ｒの受光範
囲が広いと、光電スイッチ１の投光部１Ｔからの光が被
検出物体３によって遮られているにもかかわらず、光電
スイッチ２の投光部２Ｔからの光が光電スイッチ１の受
光部ＩＲに入射する。そして投光部ＩＴ、２Ｔからはそ
れぞれ異った位相、周期のパルス光が投射されるように
なっているが、パルスの周期は似通っている場合が多く
、ぞのため投光部Ｔ、２Ｔのパルス光のタイミングが全
くφムることもあり、こうなると他の光電スイッチの投
射光の影響は四則ゲート方式だけぐは排除することがで
きない。(b) Problems with conventional technology and (b) With a pulse modulated light type photoelectric switch, only the received light input/J synchronized with the emitted light pulse is taken out, and the manual reception of light during other periods is prohibited. Since the synchronous case 175 type is adopted, there is an effect of preventing malfunctions against discontinuous noise light. However, photoelectric switches are the first choice.
As shown in Figure (a) 1, multiple units are often used side by side. In such a case, the light emitting part 1-r of the photoelectric switch
', 2T and the light receiving range of the light receiving parts IR, 2R are wide, even though the light from the light projecting part 1T of the photoelectric switch 1 is blocked by the object 3 to be detected, the photoelectric switch 2 The light from the light projecting section 2T enters the light receiving section IR of the photoelectric switch 1. The light projecting parts IT and 2T project pulsed light with different phases and periods, but the pulse periods are often similar, so the light projecting parts T and 2T The timing of the pulsed light may be completely different from φ, and in this case, the influence of the projected light from other photoelectric switches cannot be eliminated only by using the four arithmetic gate method.

このため従来は第１図（ｂ）に示すように、投光部ＩＴ
、２Ｔ及び受光部ＩＲ，２Ｈの投光範囲及び受光範囲を
狭くして、他の充電スイッチからの投射光が別の光電ス
イッチの受光部に入射しないようにすることが考えられ
ている。しかしながらこうすると、対応する投光部と受
光部との光軸を合わせることが困難になり、振動ヤ）輪
１撃等により光軸が少しでもずれた場合、動作に不都合
を来たす欠白がある。For this reason, conventionally, as shown in FIG. 1(b), the light projector IT
, 2T and the light receiving sections IR, 2H are considered to have narrower light emitting ranges and light receiving ranges to prevent the projected light from other charging switches from entering the light receiving section of another photoelectric switch. However, in this case, it becomes difficult to align the optical axes of the corresponding light emitter and light receiver, and if the optical axes are even slightly shifted due to vibrations, rings, etc., there is a deficiency that will cause inconvenience in operation. .

また第１図（Ｃ）に小づ」、うに、投光部１Ｔ、２Ｔと
受光部１１’＜、２１７とを交ｎに配置することも考え
られ（いるが、被検出物体３の表面位１１４＊か良好な
場合には、反射光が他の光電スイツｆの受光部（Ｊ入射
しＵ　ｌ〕ようので不都合である１、 更に投光部を複数個並置した場合、これらが同時に投光
しないよ−）（３°投光タイミングをずらして順次投光
し、対応しｌこタイミングの受光信号のみを選択通過さ
せる１つなゲー］・回路を設けＣ相りの影響を避けよ−
５とする考え方もある。しかしながら、投光タイミング
をずらし順次投）光していくための制御回路が必要とな
り、かつこの制御回路から各々の投・受光部に同期信“
・：号を伝えるための電気的接続が必要となるため、構
成が複雑化し、結線作業が煩雑になる他、イれぞれの光
電スイッチを独立に使えない欠点がある。In addition, as shown in FIG. 1(C), it is also conceivable to arrange the light emitting parts 1T, 2T and the light receiving part 11', 217 at an intersection. 114* is good, it is inconvenient because the reflected light will enter the light receiving part (J and U l) of another photoelectric switch f1.Furthermore, if multiple light emitting parts are arranged side by side, they will emit light at the same time. (Don't do it.) (One game that shifts the light emission timing by 3 degrees and emits light sequentially, and selectively passes only the light reception signal at the corresponding timing.) ・Create a circuit to avoid the influence of phase C.
Some people think that it should be 5. However, a control circuit is required to shift the light emission timing and emit light sequentially, and this control circuit sends synchronous signals to each light emitting and receiving section.
・: Since electrical connections are required to transmit the signal, the configuration becomes complicated and the wiring work becomes complicated, and there is also the disadvantage that each photoelectric switch cannot be used independently.

（ハ）発明の目的 本発明は上記に鑑み、光・軸調整が容秘にｈなえるよう
な投・受光範囲をももながら、寥数並置した場合に相互
の電気的な接続を必要とせず、他の光電スイッチの投射
光などの雑音光による影響を除去し°誤動作を防止する
ことができる光電スイッチを提供することを目的とりる
。(c) Purpose of the Invention In view of the above, the present invention has a projection/receiving range that allows optical/axis adjustment to be carried out secretly, while eliminating the need for mutual electrical connection when multiple units are arranged side by side. It is an object of the present invention to provide a photoelectric switch that can prevent malfunctions by eliminating the influence of noise light such as light projected from other photoelectric switches.

（ニ）発明の構成と効宋 本発明によれば、パルス発振器のパルスの発生する自前
の期間に受光東予に雑音光かへ射して１じた受光信号に
のみ対応してパルス発振器の動作を一時的に停止させる
ことにより次のパルスを赳らせるようにしたので、自他
の投射光が何パルスにもわたって重なるということがｐ
ｉ　４１　＋）れ、雑音光による誤動作を防ぐことがで
きる。。(D) Structure and Effects of the Invention According to the present invention, the pulse oscillator operates only in response to the received light signal that is emitted from the noise light to the received light during the period in which the pulse of the pulse oscillator is generated. Since the next pulse is started by temporarily stopping the pulse, it is possible that the projected light of the self and the other will overlap over many pulses.
i 41 +), and malfunctions due to optical noise can be prevented. .

また、雑音光のうち実際に誤動作の原因となる期間のも
の（ご対してのみ発振器の動作が５− 停止し他の期間の９ｇＢ光【５二対しては発振器は停止
しないため、応答時間を極力早めることができる。In addition, among the noise light, the oscillator operation stops only for the period that actually causes malfunction (for the 9gB light for the other period, the oscillator does not stop, so the response time is You can speed it up as much as possible.

さらに投・受光範囲を狭くする必要がないので、光軸の
合わせやりさを損うことかなく、かつ複数個の光電スイ
ッチを並前する場合にそれらの相互の間に電気的な接続
を行なう必要もない。Furthermore, since there is no need to narrow the light emitting/receiving range, it is possible to electrically connect between multiple photoelectric switches when multiple photoelectric switches are installed without compromising the ability to align the optical axes. There's no need.

（ホ）実施例の説明 以下、本発明の　実施例についＣ図面を参照しながら説
明する。第２図において、投光部１■は、抵抗１４．１
６．１７．１８．１９、二］ンデンサ１５、ダイオ−１
〜２０．２２、二ｊンへレータ２１からなるＲＣ自励式
パルス発振器を備え、この抵抗１４と」ンデンリ１５の
時定数回路に直列にトランジスタ１３を接続して抵抗１
１．１２とともに制御回路を構成している。パルス発振
器のパルスは抵抗２３．２４、トランジスタ２５よりな
る電流増巾回路をへＣ１更に抵抗２６をへて発光ダイオ
ード（ＬＥｒｌ＞２７に送られる。受−〇− 先部１Ｒは、フォトトラン１ジスタ２９と、抵抗２８．
３１〜３４、コンデンサ３０、コンパレータ３５からな
る波形整形回路とを備え、フォトトランジスタ２９の出
力信号のうち、一定レベル瞑土の波高値をも−）信号の
みを波形整形回路により矩形波に変換するようにしてい
る。こうして矩形波にされた受光１号は、５個の７リツ
プフロツプ３６〜４０よりなるシフトレジスタに導びか
れる。これら各フリツプフ【ｌツＩＩ４゜前記パルス発
振器のパルスをクロックパルスとしており、このクロッ
クパルスのタイミングで入力が行なわれるようになって
いる。そのため特に初段のフリツー１７［１ツブ３６は
、・受光信号をパルス発振器のパルスによりゲートする
ゲート回路としての機能を果たしているつ゛各７リツプ
フＬ１ツブの出力、はＯＦ（ゲート４１及びＡＮＤゲー
川−用２（Ｊ導びり）、、：れており、受光信号が５個
連続してこのシーノドレジスタに取り込マレタトキ、Ａ
ＮＩ”１ケ４４２（７）出力が１１８１１になる。また
Ｏ　Ｒゲート４１は５個の７リツプフロツプのうちいす
れか１個の出力でも“トド′となっている場合に゛Ｈパ
どなり、全での一ノリツブ７０ツノの出１）が１″のと
き、　ｉ’４ｆわちりＯツクパルスの５個分の時間連続
しく受光信号がない場合に“１°“と々る３従−）τシ
フトレジスタはｊ″゛゛イジタル型分（ロ）路として機
能しＣいることが分る（なお、ア′ｔ［］グ型の積分（
ロ）路を用い２）　＋−とｆ）′Ｃ−きるが、この場合
にはＯＲノア１〜４１．ＡＮＤゲート４２の代わり（積
分出力のレベル検出回路を２個設け、一方の検出しｌ＼
ルを　定時間内Ｖ“１個の受光信号があつに＠合の植分
出）Ｊ！；対応させ、他方の検出レベルを６個の受光信
号が連続１ノで生じたときに達する積分出力に対応させ
ておけばよい）。ＯＲゲート４１．ＡＮＤゲート４２の
出力はＮ　Ａ　Ｎ　Ｑｌ：ゲート４３．４４、Ｎ　ＯＲ
ゲ□ 一ト４６．ＮＯＩ回路４５よりなるフリツプフロツプに
入力されろユ また、受光信号をゲートするＡ　Ｎ　Ｄゲート５３を設
けて、投光する直前以外の受光信号によりトランジスタ
ー３がオフしないよ−うにしているーこの投光する直前
というタイミングは、コンデンサー５の充電電圧により
知ることができる。コンパレータ５１と抵抗５２を付加
し、この］ンパレータ！＋１の基準電圧をコンパレータ
２１の基準電圧Ｖ２よりも少し低い電Ｔｆｖ３とする。(E) Description of Embodiments Hereinafter, embodiments of the present invention will be described with reference to drawing C. In FIG. 2, the light projector 1■ has a resistor 14.1
6.17.18.19, 2] Densor 15, Dio-1
~20.22, it is equipped with an RC self-excited pulse oscillator consisting of a two-jitter generator 21, and a transistor 13 is connected in series with the time constant circuit of this resistor 14 and a resistor 15.
Together with 1.12, it constitutes a control circuit. The pulses from the pulse oscillator are sent to a current amplification circuit consisting of a resistor 23, 24 and a transistor 25, C1, and then a resistor 26 to a light emitting diode (LErl>27). 29, and a resistor 28.
31 to 34, a capacitor 30, and a comparator 35, the waveform shaping circuit converts only the output signal of the phototransistor 29 into a rectangular wave by the waveform shaping circuit. That's what I do. The received light No. 1 thus converted into a rectangular wave is guided to a shift register consisting of five 7-lip-flops 36-40. The pulses of each of these flip-flops are used as clock pulses, and input is performed at the timing of this clock pulse. Therefore, in particular, the first-stage flip-flop L1 tube 36 functions as a gate circuit that gates the received light signal with the pulse of the pulse oscillator. 2 (J lead), ,: 5 consecutive light reception signals are taken into this seed register.
The output of the 442 (7) becomes 11811. Also, if the output of any one of the five 7-lip-flops is "TODO", the OR gate 41 will generate a When the output 1) of the 70 horns is 1", if there is no light reception signal for a period of 5 consecutive O clock pulses, "1°" is reached (3-) τ shift. It can be seen that the register functions as a digital type divider (B) and C (note that the register functions as a digital type integral (
b) By using 2) +- and f)'C-, in this case, OR Noah 1-41. Instead of the AND gate 42 (two integral output level detection circuits are provided, one of the level detection circuits is
correspond to one received light signal within a certain period of time, and set the other detection level to the integral output that is reached when six received light signals occur in succession. ).OR gate 41.The output of AND gate 42 is N A N Ql: Gate 43.44, N OR
Ge□ Oneto46. In addition, an A N D gate 53 is provided to gate the received light signal to prevent the transistor 3 from being turned off by a received light signal other than that immediately before the light is emitted. The timing just before this happens can be determined by the charging voltage of the capacitor 5. A comparator 51 and a resistor 52 are added, and this] comparator! The +1 reference voltage is set to Tfv3, which is slightly lower than the reference voltage V2 of the comparator 21.

　　　　　　　　　　　　　　　−次に第２図のＡ〜Ｇ
点の各信号波形がそれぞれ示されている第３図のタイム
チャートを参照しながら動作について説明する。第３図
ＡはＬＥＤ２７の点対電流の波形であるが、こも れはパルス発振器のパルスの波形であり、またシフトレ
ジスタのクロツタパルスの波形ぐときに他の光電スイッ
チのＬＥＤから発射されたパルス光が７７１トトランジ
スタ２９に入射して、第３図Ｂに示すような受光信号が
生じたとする。この受光信号８のタイミングとクロック
パルスへのタイミングとがφなると９− ７リツプフ０ツ７３６の出力１は第３図Ｆに小すように
“’　Ｈ”となる。− ところて゛、第４図の実線でｌＪ＜　１ように、コンデ
ンサ１５の電圧かＶ　３Ｌ：ｌ　１−τ・ある時刻ｔ１
．１〜口６の間は、ｌンパレータ５１の出力が°１゛′
となっているため受光信号１３はＡ、　Ｎ　Ｄゲート５
３で禁１トされ、トランジスタ１３はオーツしない。- Next, A to G in Figure 2.
The operation will be described with reference to the time chart of FIG. 3, which shows signal waveforms at points. Figure 3A shows the waveform of the current versus point of the LED 27, but the overlap is the waveform of the pulse from the pulse oscillator, and when the waveform of the shift register's clock pulse occurs, the pulsed light emitted from the LED of another photoelectric switch is Suppose that the light is incident on the 771 transistor 29 and a received light signal as shown in FIG. 3B is generated. When the timing of this light reception signal 8 and the timing to the clock pulse are φ, the output 1 of the 9-7 lip filter 736 becomes "H" as shown in FIG. 3F. - Then, as shown by the solid line in Fig. 4, lJ < 1, the voltage of the capacitor 15 is V 3L: l 1 - τ at a certain time t1.
．． Between 1 and 6, the output of l comparator 51 is °1'
Therefore, the received light signal 13 is A, ND gate 5
3, the transistor 13 is disabled.

したがっＣ１二」ンｆンサ１５（二はｍ続しτ充電が行
なわれる。時刻ロ６以後は］ンパレータ５１の出力がＨ
”ｋ、なるので、受光信号ＢはＡＮＤゲート５３を通り
、受光信号に応じてトランジスタ１３がオルニｌより、
コンデフリ１５への充電が停ｉｔ　′ｇるーぞの結架、
次のパルスが遅れることになる。Therefore, the output of the comparator 51 becomes H.
”k, so the light reception signal B passes through the AND gate 53, and depending on the light reception signal, the transistor 13
Charging to the converter 15 stopped.
The next pulse will be delayed.

そして時刻１１８以後トシンジスタ１３がオンになれば
再び充電が行なわれ【、時刻ｔ１９に二なると抵抗１６
．１７．１８より決まる基準電１−［ｖ２に達し、コン
パレータ２１が反転し、その出力が゛［″となる。その
ため−］ンｌンリ１５の電荷は抵抗１９．ダイオード２
０をへて］ンパレ１０− −タ２１の出力側に流入し、放電が完了する、この放電
の間、トランジスタ２５がオンになり、ＬＥＤ２７にパ
ルス市流が流れてパルス光が投射される。なお、自らの
投射光をフォトトランジスタ２９が受１ノζ受光出力が
生じた場合に、は、パルス発振器のコンデンサ１５はす
でに放電過程に入っているためトランジスタ１３がオフ
し、コンデン１１１５への充電が停止することの影響は
ない、。Then, after time 118, when the synchronizer 13 is turned on, charging is performed again.
．． 17. The reference voltage determined by 18 reaches 1-[v2, the comparator 21 is inverted, and its output becomes ``[''.Therefore, the electric charge of the 15 resistor 19 and the diode 2
0] flows into the output side of the amplifier 10--tor 21, and the discharge is completed. During this discharge, the transistor 25 is turned on, and a pulsed current flows through the LED 27, projecting pulsed light. Note that when the phototransistor 29 receives its own projected light and generates a received light output, the capacitor 15 of the pulse oscillator is already in the discharging process, so the transistor 13 is turned off and the capacitor 1115 is charged. There is no effect of stopping.

このように他の光電スイッチからの投射光を受光した場
合、パルス発振器の動作が一時的に体、止されるの（投
光タイミングが遅れ、他の光電スイツヂーの投射光のタ
イミングをはずしてパルス光を発生することになり、そ
のため自他の投射光が重なり合うことが少なくなる。そ
の結束、自他の投射光が５個連続して重なり合うという
と・・とは絶無になり、ＡＮＤゲート４２から出力が生
じることはなく、出力Ｇは“ＨＩＩになることはない。In this way, when receiving light projected from another photoelectric switch, the operation of the pulse oscillator is temporarily stopped (the light emission timing is delayed, and the timing of the projected light of the other photoelectric switch is shifted, and the pulse oscillator is temporarily stopped). As a result, it is possible to reduce the number of overlapping projection lights of the self and others.It is impossible for the projection lights of the self and others to overlap five times in a row, and from the AND gate 42. No output occurs and the output G never becomes "HII".

また、他の光電スイッチからの投射光だ【Ｊテナ＜光電
スイッ１以外の光源からのＮ８光が入射した場合でも、
この銘昌光が入射しでいる間はパルス発振器か休＋ｌ　
ｌ、　、　？１１音光が途切れてからパルスが１しく投
光パルス及びクロックパルスが生じるの（・、雑音光に
よる誤動作を防ぐことができる。１ とこ口（’：］：／／＜レータ１＋’１ｖＪＡＮＬ１り
”ｈ５３を設けないとすれば　第４図の破線で不すよう
に、雑音光の入射・が多くなるとパルス発振器の休止時
間が長くなり　投光パルスの周期及びシフトレジスタの
り【Ｊツクパルスの周期が長くなるのＣ１シフＩ・レジ
スタの全Ｃのノリツプフ［１ツ／３６〜４０が全で゛［
ド′または１１　Ｌ　ＩＩになるま（の時間も良くなり
、光電スイッチとしての応答時間１つ佼〈な−）でしま
う。Also, if the projected light is from another photoelectric switch [J tena < even if N8 light from a light source other than photoelectric switch 1 is incident,
While this famous light is incident, the pulse oscillator is inactive.
l, , ? 11 After the sound and light are interrupted, the pulse is changed to 1 and a light emitting pulse and a clock pulse are generated (・, it is possible to prevent malfunctions due to noise light. If h53 is not provided, as shown by the broken line in Figure 4, as the incidence of noise light increases, the rest time of the pulse oscillator will become longer, and the period of the light emitting pulse and the shift register ratio [the period of the J-tsuk pulse will become longer. Naru's C1 shift I register's all C's register [1/36 to 40 are all]
The response time as a photoelectric switch is shortened by 1 time, and the time required for the photoelectric switch to reach 0' or 11L II is also improved.

しかしながら、他の光電スイッチからの投射光のうち実
線″１彰響をツノえるのは、影響を受ける側の光電スイ
ッチが投光りる直前に入射する光だけであり　弛の時間
に入る光は関係しない。そこで第２図に示すように構成
することにより、投光直前に他から入射する光でき、こ
れによって応答時間を早めることが可能となるのである
。However, among the light projected from other photoelectric switches, only the light that enters immediately before the photoelectric switch on the affected side emits the light that causes the solid line ``1 light'' to appear, and the light that enters during the relaxation time is Therefore, by configuring the device as shown in FIG. 2, light can be incident from other sources just before the light is projected, thereby making it possible to speed up the response time.

【図面の簡単な説明】[Brief explanation of drawings]

第１図（ａ）、（ｂ）、（ｃ）は光電スイッチの投光部
と受光部の位置関係を示す概略的な平面図、第２図は本
発明の一実施例の回路図、第３図は第２図のＡ−Ｇの各
点における信号波形を示４タイムチャート、第４図は第
２図のコンデンサー５の充電電圧波形を小１タイムチヤ
ートである。 ＩＴ、２Ｔ・・投光部　ＩＲ，２Ｒ・・受光部撒 ３・・ｌ、検出物体　　　２７・・投光用ＬＥＤ２９・
・フォトトランジスタ（受光素子）３６・〜・４０・φ
フリツＪフＯツブ ５１・・」ンパレータ　５３・・Ａ　Ｎ　Ｄゲート特許
出願人　　立石電機株式会社 １３− 第１霞 （ｃ）1(a), (b), and (c) are schematic plan views showing the positional relationship between the light emitting part and the light receiving part of the photoelectric switch; FIG. 2 is a circuit diagram of an embodiment of the present invention; FIG. 3 is a 4-time chart showing the signal waveform at each point A to G in FIG. 2, and FIG. 4 is a small 1-time chart showing the charging voltage waveform of the capacitor 5 in FIG. IT, 2T... Light emitter IR, 2R... Light receiver 3...l, detection object 27... LED for light emitter 29...
・Phototransistor (light receiving element) 36・〜・40・φ
Frits J Fub 51...'' Emparator 53... A N D Gate Patent Applicant Tateishi Electric Co., Ltd. 13- 1st Kasumi (c)

Claims (1)

【特許請求の範囲】[Claims] （１）パルス発振器と、このパルス発振器から出力され
るパルスに吟じてパルス１点灯する発光素子と、前記発
光素子からの光を受けて受光信号を生じる受光素子と、
この受光信号を前記パルス発振器からのパルスによって
ゲートするためのゲート回路と、このゲート回路の出力
を積分する積分１１．ＩＪ路と、前記パルス発振器のパ
ルスの発生する直前の期間に前記受光素子に雑音光が入
射して生じた受光信号にのみ対応して前記パルス発振器
の動作を一時的に停止させることにより次のパルスを遅
らせる制御回路とを備えたことを特徴とする光電スイッ
チ。(1) a pulse oscillator, a light emitting element that lights up one pulse in response to a pulse output from the pulse oscillator, and a light receiving element that receives light from the light emitting element and generates a light reception signal;
a gate circuit for gating this light reception signal with a pulse from the pulse oscillator; and an integration unit 11 for integrating the output of this gate circuit. By temporarily stopping the operation of the pulse oscillator only in response to the IJ path and a light reception signal generated by noise light incident on the light receiving element during the period immediately before the pulse of the pulse oscillator is generated, the following can be achieved. A photoelectric switch characterized by comprising a control circuit that delays a pulse.