【０００１】
【発明の属する技術分野】
本発明は住居のセキュリティとか工作機械等における安全装置に用いられる物体感知装置に関する。
【０００２】
【従来の技術】
一般住居，事務所，倉庫等で無資格者が進入するのを阻止するとか、プレス機械で不用意に人の手が機械の間に入ったのを検知して機械の動作を停止させる等の保安装置は原理的には、人体とかその一部などの物体の通路に放射線のカ−テンを作って置いて、受線手段により放射線がそれらの物体で遮られたことを検知して警報信号を発信すると云う構造になっている。
こゝで放射線としては多くの場合光が用いられ、受線手段としてはフォトダイオ−ドとかＣＤＳが用いられる。所で従来は上述した放射線のカ−テンを形成するため、ビ−ム状の光を出す光源装置を複数並べ、各光源装置と対向させて受光装置を配置すると云う構成を用いているので、物体の通過可能な領域の断面積が大きい場合は、光源装置，受光装置とも多数を要し、保安装置の設置工事が大げさになり、また保安装置の保守点検も面倒になると云う問題があった。
【０００３】
【発明が解決しようとする課題】
本発明は上述したような光電式の物体感知装置で光源装置と受光装置の数を少なくして装置自体を安価にすると共に設置工事をも簡単なものにしようとするものである。
【０００４】
【課題を解決するための手段】
扇形板状の光束を発射する投光装置と、この投光装置に近接して配置された一乃至複数個の受光装置とよりなる投受光手段と上記受光装置の受光出力の減少を検出して警報信号を出す回路と、入射光を入射方向に反射する再帰性反射シ−トの帯とで物体感知装置を構成し、物体通路の内面に、物体通路を囲むように上記反射シ−トの帯を配設し、この反射シ−トに投光するように上記投受光手段を設置した。
【０００５】
【発明の実施の形態】
図１に本発明の実施形態の一例を示す。図で１は物体例えば人Ｂの通路で、図の紙面に垂直の方向が物体の通過方向である。図１Ａは物体通路の垂直断面であり同Ｂは水平断面で通路の天井側を示す。２は投受光手段で図１Ａにａで示す角範囲に拡がる扇形板状の光束を発射している。３は再帰性反射シ−トの帯で、通路１を鍵の手に囲むように通路１の壁に貼設されている。再帰性反射シ−トは微少な全反射プリズム或はガラスビ−ズを接着材でベ−スシ−トに密に付着させたシ−トで、入射光を入射方向に反射させる性質を持っている。市販品はベ−スシ−トの裏面に貼着材層が設けてあるので、簡単に通路壁面に貼設することが出来るものである。
投受光手段２は鍵の手に貼設されたシ−ト３の隅角と対向する通路下隅近くに設置される。投受光手段２は発光素子と投光光学系と、投光光学系の傍らに位置させた受光素子より成っており、図に両方向の矢印で示すように投受光手段２より発射された光線は再び投受光手段に戻って来て受光素子に入射する。この構造により発光素子より放射された光は通常は略全部が受光素子で受光され、受光素子の出力は最大を示している。
こゝで物体Ｂが通路１を通ると、投受光手段２から発射される光の一部は物体で散乱され、受光素子に入射するシ−ト３からの反射光量が減少する。この減少を検出することで物体の通過を検知するのである。
Ｗはシ−ト３の中央辺で投受光手段２からの光を受光する位置に設置された受光素子で、投受光手段２とは別の電源系統で駆動される警報装置に接続せれており、投受光手段とそれに付随する警報回路の電源が切断されたり投受光手段２が外されたようなとき、受光手段Ｗの受光出力が０になることによって警報を発すためのものである。
【０００６】
図２は投受光手段の一つの構成例を示す。図２Ａで投受光手段の投光光学系は半導体レ−ザＳと集光レンズＬと円柱レンズＣが鏡筒５に取付けられた構造で、受光装置は鏡筒５の前端の板状部５１上で円柱レンズＣの両側（片側でも良い）に配置されたＣＤＳ（或はフォトダイオ−ドでもよい）Ｄである。
鏡筒５は後端（図では下端）が開放され、前端は板状部５１で塞がれた形で、板状部５１の中央に長方形の透孔５２が設けられている。この透孔の幅は円柱レンズＣの直径より稍せまく、円柱レンズＣが半ば嵌ってその位置が決まるようになっている。鏡筒５の内面の上端近くには段５３が形成されており、集光レンズＬの座面となって、レンズＬを下方から押すことでレンズＬの位置が決まるようになっている。
６は半導体レ−ザＳの取付け基板兼放熱板で、鏡筒５に嵌合する円形部の両側に張り出し部があり、この張り出し部が鏡筒５の下端口縁の切欠部に嵌合して、鏡筒５に対する半導体レ−ザＳの位置が決まる。７はレンズＬを鏡筒５内の段に向かって押圧しているばねである。
鏡筒の板状部５１には円柱レンズＣの両側にＣＤＳのＤのリ−ド線を通す溝５４が形成されている。８は円環形の回路基板で鏡筒５に嵌着され、ＣＤＳのＤはこの回路基板に接続されている。
図２Ｂは装置２の全体を示し、９は四半円形の外ケ−スで隅角部内側に４５°の方向で投受光手段が固定されており、四半円部には天文台の窓のように午線に沿って一つのスリット９１を有し、このスリットが円柱レンズＣの軸線と直交する向きになっている。このためＣＤＳＤに再帰性反射シ−ト３からの反射光以外の方向から来る雑光が入射するのが防がれている。外ケ−スが四半円形であるのは、この装置を通路の隅に設置するのに適しているからである。
図２Ａに戻って１０は円柱レンズＣを板状部５１の長方形の透孔５２に向かって押え込んで固定する板ばねで、両端の鍵状部を板状部５１の外周に係止させて板状部に固定するようにしてある。
１１は円柱レンズＣと受光素子（ＣＤＳ）Ｄとの間に立てられた遮蔽板で、円柱レンズＣで扇形に広がるレ−ザ−光が直接受光素子Ｄに入射するのを防いでいる。
【０００７】
図３は市販されている再帰性反射シ−トの例でマイクロプリズムを用いたものである。Ｐがマイクロプリズムで１ｃｍ２ 当たり７４００個のプリズムが配列されている。各プリズムは立方体の角を対角線に垂直な面で切り取った形で入射光は３回反射して元来た方向に帰って行く。プリズム面はメッキを施してある。ｂはポリエステルの基材、ｃは保護コ−ティング層、ｈは粘着材層で、ｒは離型紙である。離型紙を除いたシ−トの厚さは０．２ｍｍで柔軟性が良い。
【０００８】
図４は本発明で用いられる回路の一例である。おの装置は商用交流で駆動してもよいが、電池を電源としても良い。この場合電池直流を交流化して半導体レ−ザを駆動し、受光回路もこの交流に同期させて動かせば一般の照明光とか外光の影響を除去出来る利点がある。受光素子のＣＤＳＤはこの例では２個用いているので、その出力がＣＰＵに入力される。ＣＰＵの動作の１例をアナログ的に述べると、受光素子Ｄの出力を加算回路で加算し、その出力を増幅器増幅し、その出力を二つに分けて一方は整流平滑化して交流出力のピ−ク値を保持させ、保持された電圧を少し減圧して比較回路の−端子に印加する。二つに分けた他方は直接比較回路の＋端子に印加する。比較回路Ｃｐの出力を整流して＋出力だけを取り出す。通常はこの出力は正であるが、物体が投受光手段によって形成されている光のカ−テンを過ぎるとき、上記増幅器Ｆの出力のピ−ク値は比較回路Ｃｐの−端子入力電圧より下になるから、比較回路Ｃｐの出力は負となり、整流出力は０となる。この出力が０になったことが物体感知信号となり、これによってブザ−Ｋが作動せしめられる。
【０００９】
図５は本発明の異なる実施形態を示す。この例では投光手段を２，２’の二つ用い、夫々を通路１の一方の側の上下両隅に配置じ、通路の反対側の側壁のみに再帰性反射シ−トを貼設したものである。この例でも図１の例でも、平面反射鏡Ｍを配置し、２，２’からの光の反射光来る位置に受光素子Ｗ，Ｗ’を配置してもよい。
【００１０】
【発明の効果】
本発明物体感知装置は光のカ−テンを構成するのに扇形に広がる光束を発射する投光器と再帰性反射体を用いることにより、一つの投光器と一つ（複数でも可）の受光器とで物体の通路断面をカバ−する光のカ−テンが出来るので、装置構成がきわめて簡単で安価になり、特に設置工事が大変簡単になると云う利点がある。
【図面の簡単な説明】
【図１】本発明の一実施例を示す図。
【図２】本発明の一実施例における投受光装置の分解斜視図。
【図３】再帰性反射体の一例の断面図。
【図４】本発明における回路部分の回路図。
【図５】本発明の他の実施例を示す図。
【符号の説明】
１ 物体の通路
２ 投受光装置
３ 再帰性反射シ−トの帯
Ｓ 半導体レ−ザ
Ｌ 集光レンズ
Ｃ 円柱レンズ
Ｄ ＣＤＳ，フォトダイオ−ド等の受光素子[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an object sensing device used for security of a house or a safety device in a machine tool or the like.
[0002]
[Prior art]
To prevent unqualified persons from entering in ordinary dwellings, offices, warehouses, etc., or to stop the operation of the machine by detecting the inadvertent entry of a hand between machines by a press machine In principle, a security device creates a radiation curtain in the path of an object, such as the human body or a part thereof, and detects that the radiation has been blocked by those objects by receiving means, and issues an alarm signal. Is transmitted.
Here, light is used in most cases as radiation, and a photodiode or CDS is used as a receiving means. Conventionally, in order to form the above-described curtain of radiation, a configuration is used in which a plurality of light source devices that emit beam-like light are arranged, and a light receiving device is arranged in opposition to each light source device. When the cross-sectional area of the area through which an object can pass is large, both the light source device and the light receiving device are required in large numbers, and the installation work of the security device becomes large, and the maintenance and inspection of the security device become troublesome. .
[0003]
[Problems to be solved by the invention]
An object of the present invention is to reduce the number of light source devices and light receiving devices in the photoelectric type object sensing device as described above, to reduce the cost of the device itself, and to simplify the installation work.
[0004]
[Means for Solving the Problems]
A light projecting device that emits a fan-shaped plate-shaped light beam, light projecting / receiving means including one or more light receiving devices arranged in close proximity to the light projecting device, and detecting a decrease in the light receiving output of the light receiving device. A circuit for issuing an alarm signal and a band of a retroreflective sheet for reflecting incident light in the incident direction constitute an object sensing device, and the reflection sheet is provided on the inner surface of the object passage so as to surround the object passage. A band was provided, and the above-mentioned light emitting and receiving means was installed so as to emit light to the reflection sheet.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows an example of an embodiment of the present invention. In the figure, reference numeral 1 denotes a passage of an object, for example, a person B, and the direction perpendicular to the plane of the drawing is the passing direction of the object. FIG. 1A is a vertical cross section of the object passage, and FIG. 1B is a horizontal cross section showing the ceiling side of the passage. Numeral 2 denotes a light emitting / receiving means for emitting a fan-shaped plate-like light beam which spreads in the angular range indicated by a in FIG. 1A. Reference numeral 3 denotes a band of a retroreflective sheet, which is attached to the wall of the passage 1 so as to surround the passage 1 with a key. The retroreflective sheet is a sheet in which a minute total reflection prism or a glass bead is adhered to a base sheet densely with an adhesive, and has a property of reflecting incident light in the incident direction. . Commercially available products have an adhesive layer provided on the back surface of the base sheet, so that they can be easily attached to the passage wall surface.
The light emitting and receiving means 2 is installed near the lower corner of the passage facing the corner of the sheet 3 attached to the hand of the key. The light emitting and receiving means 2 is composed of a light emitting element, a light emitting optical system, and a light receiving element located beside the light emitting optical system, and the light beam emitted from the light emitting and receiving means 2 is indicated by a double-headed arrow in the figure. It returns to the light emitting and receiving means again and enters the light receiving element. With this structure, almost all of the light emitted from the light emitting element is received by the light receiving element, and the output of the light receiving element indicates the maximum.
Here, when the object B passes through the passage 1, a part of the light emitted from the light emitting / receiving means 2 is scattered by the object, and the amount of reflected light from the sheet 3 incident on the light receiving element decreases. By detecting this decrease, the passage of the object is detected.
W is a light receiving element installed at a central side of the sheet 3 at a position for receiving light from the light emitting and receiving means 2, and is connected to an alarm device driven by a power supply system different from the light emitting and receiving means 2. When the power of the light emitting / receiving means and its associated alarm circuit is turned off or the light emitting / receiving means 2 is removed, an alarm is issued when the light receiving output of the light receiving means W becomes zero.
[0006]
FIG. 2 shows one configuration example of the light emitting / receiving means. In FIG. 2A, the light projecting optical system of the light projecting and receiving means has a structure in which a semiconductor laser S, a condenser lens L and a cylindrical lens C are mounted on a lens barrel 5, and the light receiving device is a plate-like portion 51 at the front end of the lens barrel 5. The CDS (or photo diode) D is disposed on both sides (or one side) of the cylindrical lens C above.
The rear end (lower end in the figure) of the lens barrel 5 is opened, and the front end is closed by a plate-shaped portion 51, and a rectangular through hole 52 is provided in the center of the plate-shaped portion 51. The width of this through hole is slightly smaller than the diameter of the cylindrical lens C, and the position of the cylindrical lens C is determined by being fitted halfway. A step 53 is formed near the upper end of the inner surface of the lens barrel 5 and serves as a seating surface of the condenser lens L. The position of the lens L is determined by pushing the lens L from below.
Reference numeral 6 denotes a mounting board and heat sink for mounting the semiconductor laser S, and has a projecting portion on both sides of a circular portion fitted to the lens barrel 5. The projecting portion fits into a cutout at the lower edge of the lens barrel 5. Thus, the position of the semiconductor laser S with respect to the lens barrel 5 is determined. Reference numeral 7 denotes a spring that presses the lens L toward a step in the lens barrel 5.
On the plate-like portion 51 of the lens barrel, grooves 54 are formed on both sides of the cylindrical lens C so as to pass the lead wire D of the CDS. Reference numeral 8 denotes an annular circuit board which is fitted to the lens barrel 5, and D of the CDS is connected to the circuit board.
FIG. 2B shows the whole apparatus 2, and 9 is a quarter-circle outer case in which the light emitting and receiving means is fixed in the direction of 45.degree. Inside the corner, like a window of an observatory in the quarter circle. It has one slit 91 along the meridian, and this slit is oriented in a direction perpendicular to the axis of the cylindrical lens C. For this reason, it is possible to prevent noise light coming from directions other than the reflected light from the retroreflective sheet 3 from entering the CDSD. The outer case is quarter-circular because it is suitable for installing the device in a corner of a passage.
Returning to FIG. 2A, reference numeral 10 denotes a leaf spring for pressing and fixing the cylindrical lens C toward the rectangular through hole 52 of the plate portion 51, and locking the key portions at both ends to the outer periphery of the plate portion 51. It is designed to be fixed to a plate-like part.
Reference numeral 11 denotes a shielding plate provided between the cylindrical lens C and the light receiving element (CDS) D, which prevents the laser light spreading in a fan shape by the cylindrical lens C from directly entering the light receiving element D.
[0007]
FIG. 3 shows an example of a commercially available retroreflective sheet using a microprism. P is a microprism, and 7400 prisms are arranged per cm 2. In each prism, the incident light is reflected three times and returns to the original direction in a form in which the corner of the cube is cut off at a plane perpendicular to the diagonal line. The prism surface is plated. b is a polyester base, c is a protective coating layer, h is an adhesive layer, and r is a release paper. The thickness of the sheet excluding the release paper is 0.2 mm, which is excellent in flexibility.
[0008]
FIG. 4 is an example of a circuit used in the present invention. Each device may be driven by a commercial AC, but a battery may be used as a power source. In this case, if the battery DC is converted to AC to drive the semiconductor laser and the light receiving circuit is operated in synchronization with the AC, there is an advantage that the influence of general illumination light or external light can be removed. Since two CDSDs are used as the light receiving elements in this example, the output is input to the CPU. If an example of the operation of the CPU is described in an analog manner, the output of the light receiving element D is added by an adder circuit, the output is amplified by an amplifier, the output is divided into two, and one is rectified and smoothed, and the AC output peak is obtained. Then, the stored voltage is slightly reduced and applied to the negative terminal of the comparison circuit. The other of the two is applied directly to the + terminal of the comparison circuit. The output of the comparison circuit Cp is rectified to extract only the + output. Normally, this output is positive, but when the object passes through the light curtain formed by the light emitting and receiving means, the peak value of the output of the amplifier F is lower than the negative terminal input voltage of the comparison circuit Cp. , The output of the comparison circuit Cp becomes negative, and the rectified output becomes zero. When this output becomes 0, it becomes an object detection signal, and the buzzer K is activated by this.
[0009]
FIG. 5 shows a different embodiment of the present invention. In this example, two light emitting means 2 and 2 'are used, each of which is disposed at the upper and lower corners on one side of the passage 1, and a retroreflective sheet is attached only to the side wall on the opposite side of the passage. Things. In this example and in the example of FIG. 1, the plane reflecting mirror M may be arranged, and the light receiving elements W and W 'may be arranged at positions where the reflected light of the light from the light beams 2 and 2' comes.
[0010]
【The invention's effect】
The object sensing apparatus of the present invention uses a projector and a retroreflector that emit a fan-shaped luminous flux to form a light curtain, so that one projector and one (or more) light receivers can be used. Since the light curtain covering the passage cross section of the object can be formed, there is an advantage that the apparatus configuration is extremely simple and inexpensive, and particularly the installation work is very simple.
[Brief description of the drawings]
FIG. 1 is a diagram showing one embodiment of the present invention.
FIG. 2 is an exploded perspective view of the light emitting and receiving device in one embodiment of the present invention.
FIG. 3 is a sectional view of an example of a retroreflector.
FIG. 4 is a circuit diagram of a circuit portion according to the present invention.
FIG. 5 is a diagram showing another embodiment of the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 object path 2 light emitting / receiving device 3 band of retroreflective sheet S semiconductor laser L condensing lens C cylindrical lens D CDS, light receiving element such as photo diode