PHOTOELECTRIC SENSORS

Transcription

1 Photoelectrc INTRODUCTI Prncples of operaton Photoelectrc sensor s a generc name for sensors whch detect an object by usng lght. The optcal sgnal transmtted from the emttng part of the sensor s modfed by beng reflected, transmtted, absorbed, etc., by the sensng object and s then detected by the recevng part of the sensor to generate a correspondng output sgnal. Further, t can also be a sensor whch detects lght radated from the sensng object to generate an output sgnal. Emttng method Pulse-modulated Most of the photoelectrc sensors emt a beam whch s pulse-modulated. In ths method, a strong optcal sgnal of fxed wdth s emtted at a fxed tme nterval. Ths helps the recever to dstngush the sgnal from extraneous lght and to acheve a long sensng range. Inductve Proxmty Thru-beam type Emttng Reflected beam Sensng object Transmtted beam Recevng Emtted beam ntensty Emtter Retroreflectve type Recevng Reflectve type The sensng object nterrupts the beam Sensng object Recever Reflected beam Emttng Transmtted beam The sensng object nterrupts the beam Unmodulated Tme The hgh-speed fber sensor FX2-A3R and the mcro photoelectrc sensor PM seres use an unmodulated beam. In ths method, the beam s emtted constantly at a fxed ntensty. Ths enables hgh-speed response, although the sensors are a lttle susceptble to extraneous lght as compared to the sensors usng a modulated beam. Recevng Emttng Sensng object Reflected beam Transmtted beam The sensng object reflects the beam Emtted beam ntensty Tme FEATURES Non-contact detecton Detects an object wthout contact. Non-contact sensng ensures longer lfe for the sensor and absolutely no damage to the object. Long sensng range The thru-beam type wth a maxmum sensng range of m ft (RX-M), and the dffuse reflectve type wth a maxmum sensng range of m ft (PX-26) are avalable. The long sensng range make the sensors sutable for a varety of applcatons. Varous objects detectable The sensors can detect objects of any materal provded they affect the optcal beam. Hgh-speed response The use of an optcal beam for detecton and complete electronc crcutry makes the sensors respond so quckly that they can be easly used on a hgh-speed producton lne. Color dentfcaton Ths s a specal feature of photoelectrc sensors, whch use lght for detecton. Snce the reflecton and the absorpton characterstcs vary wth the object color for a specfed ncdent optcal wavelength, varous colors can be detected as the dfference n optcal ntensty. Hgh accuracy detecton Advanced optcal system and electronc crcut technology have acheved a sensng accuracy of up to 2!m.787 ml (SH-82R). m Photoelectrc sensors have the drawback that f the lens surface s covered wth dust or drt and lght transmsson s obstructed, detecton may not be possble. 1124

2 TYPES OF SENSORS Classfcaton methods There are varous types of photoelectrc sensors. Four dfferent methods of classfcaton, dependng on the objectve consdered, are explaned here. 1 Classfcaton by structure Ths classfcaton s based on the manner n whch the crcut confguraton s are bult-n or separated. Ths classfcaton s useful to select sensors n vew of the mountng space, power and nose mmunty. 3 Classfcaton by beam source Ths classfcaton s based on the type of beam source used. Ths classfcaton s useful to select sensors n vew of the sensng dstance and the color dfferences of objects. Photoelectrc Photoelectrc sensor Amplfer bult-n Power bult-n Amplfer-separated Photoelectrc sensor Infrared beam Red beam Green beam Inductve Proxmty Fber type Blue beam Three color beam (Red Green Blue) 2 Classfcaton by sensng mode Ths classfcaton s based on how the lght s emtted and receved and on the sensor shape. Ths classfcaton s useful to select sensors n vew of the sensng object sze and the surroundng condtons. Photoelectrc sensor Thru-beam type Retroreflectve type General purpose U-shaped Area General purpose Wth polarzng flters Transparent object detecton Dffuse reflectve 4 Classfcaton by output crcut Ths classfcaton s based on the type of output crcut and the output voltage. Ths classfcaton s useful to select sensors accordng to the nput condtons of the devce or equpment connected to the sensor output. Photoelectrc sensor Non-contact DC 2-wre NPN open-collector transstor PNP open-collector transstor NPN transstor unversal AC non-contact (Thyrstor) Analog voltage Narrow-vew reflectve Wth contact Relay contact Reflectve type Convergent reflectve Adjustable range & fxed focus Mark sensng 112

3 TYPES OF SENSORS Classfcaton 1 Classfcaton by structure Photoelectrc Inductve Proxmty Fber Amplfer-separated Power bult-n Amplfer bult-n DC power AC or DC power DC power Non-contact output DC power Non-contact output Recevng Amplfer + crcut Emttng Non-contact output Recevng Amplfer + crcut Power crcut Emttng Relay contact output Amplfer Amplfer + crcut Amplfer Amplfer + crcut Recevng Emttng Outlne and Features head Fber Recevng Emttng Snce the amplfer s bult-n, just connectng the DC power can provde a relay drve output. Snce all necessary functons of a photoelectrc sensor are ncorporated, just connectng the power (1V / 2V AC) can provde a relay contact output. As the sensor head contans only the emttng and the recevng s, ts sze can be made small. Further, the senstvty adjustment can be done from a remote place. It has supreme envronmental resstance, snce the sensng porton (fber) contans absolutely no electrcal parts. Feature comparson table Feature head sze Nose mmunty Lfetme Ease of use g g g f g f f g : Excellent g: Good f: Far (Refer to p.1138) 1126

4 TYPES OF SENSORS 2 Classfcaton by sensng mode Thru-beam Retroreflectve General purpose U-shaped Area General purpose Wth polarzng flters Transparent object detecton Outlne and Features Detects an object that nterrupts the lght beam travelng from the emtter to the recever. Emtter The emtter and the recever are n one enclosure. Lght curtan s made up of arrayed emttng and recevng s. Emtter Effectve lght beam mcross-beam scannng Detects an object that has a reflectvty smaller than the reflector and nterrupts the lght beam travelng between the sensor and the reflector. It enables detecton of even a specular object by attachment of polarzng flters to the emttng and the recevng parts. (Refer to p.1138) The specally devsed optcal system enables detecton of even a transparent object. Emtter Sensng object Recever Effectve lght beam Recever Recever Long sensng range Precse detecton Small object detectable Not affected by shape, color or materal of sensng objects (opaque) Resstant to drt and dust on the lens No beam algnment needed Precse detecton Small object detectable Not affected by shape, color or materal of sensng objects (opaque) Resstant to drt and dust on the lens Object s detectable as long as t s anywhere n the defned sensng area Not affected by shape, color or materal of sensng objects (opaque) Resstant to drt and dust on the lenses Thn objects, such as postcards, can be detected Cross-beam scannng type only. Refer to p ( ) Easy beam algnment Wrng only on one sde Space savng compared to thru-beam type sensors Not affected by shape, color or materal of sensng objects (opaque) Specular object detecton Easy beam algnment Wrng only on one sde Space savng compared to thru-beam type sensors Not affected by shape, color or materal of sensng objects (opaque) Transparent object detecton Easy beam algnment Wrng only on one sde Space savng compared to thru-beam type sensors Not affected by shape, color or materal of sensng objects Reflectve Dffuse reflectve Narrow-vew reflectve Convergent reflectve Adjustable range & fxed-focus reflectve Mark sensng Outlne and Features Emts a beam onto the object and detects the object by recevng the beam reflected from the object surface. The sensng area s narrowed by the optcal system. Detects an object n the area where the emttng and the recevng envelopes overlap. A spot-beam type sensor detects an object at just the pont where these envelopes cross over. Emts a spot beam onto an object and senses the dfference n the reflected beam angle. (Refer to p.1138) Projects a spot-beam on the target color, and dentfes the color by sensng the amount of reflected beam and the relatve rato among color components. Amplfer Sensng area Sensng area Sensng area Fber (FZ-1 seres) No beam algnment needed Space savng Wrng only on one sde Object wth fluctuatng poston detectable Wde sensng area Hardly affected by surroundngs More accurate detecton compared to dffuse reflectve type sensors No beam algnment needed Space savng Wrng only on one sde Less affected by background and surroundngs Precse detecton No beam algnment needed Space savng Wrng only on one sde Not affected by shape, color or materal of sensng objects Hardly affected by background and surroundngs Small object detectable wth hgh accuracy No beam algnment needed Space savng Wrng only on one sde Not susceptble to temperature drft and voltage fluctuaton Color dentfable Hardly affected by background and surroundngs Small object detectable wth hgh accuracy No beam algnment needed Space savng (FZ-1 seres) Wrng only on one sde Photoelectrc Inductve Proxmty 1127

5 Photoelectrc Inductve Proxmty TYPES OF SENSORS 3 Classfcaton by beam source Infrared beam Red beam Green beam Blue beam Features Intense beam offers long sensng range Unable to expose flms Sutable for color mark sensng Vsble Sutable for color mark sensng Sutable for mnute detecton because of a hgh beam dampng rato. Vsble Sutable for color mark sensng Sutable for mnute detecton because of a hgh beam dampng rato. Vsble Mark Background color color Whte Yellow Orange Red Green Blue Black Whte b b gb rgb rgb rgb Yellow b g g rgb rgb rgb Orange b g gb rgb rgb rgb Red gb g gb r rb rb Green rgb rgb rgb r b b Blue rgb rgb rgb rb b b Black rgb rgb rgb rb b b Color combnatons that can be dscerned durng mark sensng r: Red LED type g: Green LED type b: Blue LED type Three color beam (Red Green Blue) Color detected by resolvng t nto three color components Fne color dscrmnaton possble 1128

6 TYPES OF SENSORS 4 Classfcaton by output crcut Wth contact Relay contact Non-contact DC 2-wre NPN open-collector transstor Outlne and Features Drves AC load or DC load Large swtchng capacty Delayed response compared to non-contact output crcut Power crcut relay Internal crcut Power Wre savng Low current consumpton Sem-permanent lfe Hgh-speed response Lmtaton on connectable load crcut Tr Internal crcut ZD NO Load NC (Some models do not ncorporate t.) COM. Users crcut Breeder resstance Users crcut Load Load Symbols... ZD: Surge absorpton zener dode Tr : PNP output transstor Able to drve a relay, PLC, TTL logc crcut, etc. A separate power can be used for the load. Sem-permanent lfe Hgh-speed response Commonly used n North Amerca or Japan crcut ZD Tr D Internal crcut V V Users crcut Load Symbols... D: Reverse polarty protecton dode ZD: Surge absorpton zener dode (Its poston dffers wth the model.) Symbol... Tr : NPN output transstor AC / DC power AC / DC power DC power DC power Non-contact NPN transstor unversal AC non-contact (Thyrstor) Analog voltage Outlne and Features Able to drve a relay, PLC and logc crcut Sem-permanent lfe A separate power can be used for the load. (However, ts voltage must be hgher than the sensor power.) Hgh-speed response crcut Tr D2 D1 Internal crcut ZD V V Users crcut Load Symbols... D1: Reverse polarty protecton dode (Its poston dffers wth the model.) Symbols... D2: Reverse current preventon dode (Its poston dffers wth the model.) Symbols... ZD: Surge absorpton zener dode Symbols... Tr : NPN output transstor Able to drve AC load drectly Sem-permanent lfe crcut Thyrstor Internal crcut AC IN AC IN Users crcut Load DC power AC power s an analog voltage proportonal to the amount of ncdent beam crcut 7 V D1 D2 47 Ω D3 Internal crcut V Analog voltage output Load 2 kω or more load V resstance Users crcut Symbols... D1: Reverse polarty protecton dode Symbols... D2, D3: Surge absorpton dode DC power Photoelectrc Inductve Proxmty PNP open-collector transstor Commonly used output crcut n Europe Power s not requred for the load. Sem-permanent lfe Hgh-speed response crcut ZD Tr D Internal crcut V V Users crcut Load Symbols... D: Reverse polarty protecton dode (Its poston dffers wth model.) Symbol... ZD: Surge absorpton zener dode (Its poston dffers wth the model.) Symbol... Tr : PNP output transstor DC power 1129

7 Inductve Proxmty Photoelectrc 4 Classfcaton by output crcut FX-31 FX-32 FX-33 FX-311 FX-11A FZ-1 CX-4 EX-3 EX-2 EX-1 EQ-2 EQ-3 EX-4 RX RX-LS2 CY PX-2 RT-61 PM PM2 NX Dgtal settng Manually set Analog output Color detecton Amplfer bult-n Mcro Fber sensors Photoerectrc sensors Item Seres name 3 Classfcaton by beam source Reflectve 2 Classfcaton by sensng mode Retroreflectve Thru-beam 1 Classfcaton by structure TYPES OF SENSORS Classfcaton table Amplfer bult-n type Power bult-n Amplfer-separated type (DC power ) Fber type General use purpose U-shaped Area Others General use purpose Wth polarzng flters Transparent object detecton Dffuse reflectve Narrow-vew reflectve Convergent reflectve Adjustable range & fxed-focus reflectve Mark sensng Others Infrared beam Red beam Green beam Blue beam Three color beam (Red Green Blue) Relay contact DC 2-wre NPN opencollector transstor PNP opencollector transstor NPN transstor unversal AC non-contact (Thyrstor) Analog voltage Notes: 1) It must be connected to an exclusve controller (DC power, NPN open-collector transstor). Notes: 2) It must be conected to an exclusve controller (DC power, Analog voltage) 113 SF4-AH SF2-A SF2-N SF2-EH SF1-F Lght curtans for safeguard (Note 1) (Note 1) VF EQ- SU-7/SH SS-A Power bult-n Amplferseparated : Applcable model NA2-N Indvdual beam outputs NA1-11 NA1-PK/ NA1-PK3 M-DW1 FT-K FD-L43 FD-L41/L42 SH-72 M HD-T1 EX-F7/F6 FD-F7 FT-F9 FX-31-F EX-F1 FD-F4/F9 FD-F8Y FT-Z8Y Slm body Pckng Area sensors for semconductor ndustry Glass substrate / wafer sensng Leak lqud / Lqud level sensng (Note 2) FT-L8Y/V8Y Chemcal-resstant FD-H3-L32, FD-H18-L31 EZ-1 Heat-resstant Water detecton Partcular use sensor 1131

8 GLOSSARY Term Descrpton Term Descrpton Photoelectrc Inductve Proxmty Beam envelope Beam axs Sensng axs Beam envelope: Beam spread Beam axs: The center axs of lght beam The center axs between the emtted beam axs and the receved beam axs. For the thru-beam type sensor, t s dentcal to the beam axs. Receved beam axs Sensng axs Standard sensng object The standard sensng object for determnng the basc specfcatons of reflectve type sensors. Normally, t s whte non-glossy paper, but some partcular sensors use other objects to sut the applcaton. (e.g., glass) The mnmum object sze that the sensor can detect under the specfed condtons. In the thru-beam type and the retroreflectve type, the sze of an opaque object s specfed. In the dffuse reflectve type, the dameter of a gold wre or a copper wre s specfed. ("xxx mm "xxx n value s expressed) Thru-beam type Mnmum sensng object Reflectve type Mnmum sensng object Emtted beam axs Thru-beam type The dstance whch can be set between the emtter and the recever under the stable sensng condton. (The abbrevaton l s set for values startng from.) Mnmum sensng object "a mm "a n Retroreflectve type "a mm "a n Sensng range Emtter Recever Retroreflectve type The dstance whch can be set between the sensor and the reflector under the stable sensng condton. (The abbrevaton l s set for values startng from.) Sensng range Hysteress "a mm "a n For a reflectve type sensor, the hysteress s the dfference between the operaton dstance, when the output frst turns wth the standard sensng object approachng along the sensng axs, and the resumpton dstance, when the output frst turns wth the standard sensng object recedng. Sensng range Dstance to convergent pont Reflectve type The dstance whch can be set between the sensor and the standard sensng object (normally, whte non-glossy paper) under the stable sensng condton. (The abbrevaton l s set for values startng from.) Sensng range The dfference n the operatng poston when operaton s repeated under constant condtons. Reflectve type Operaton Hysteress dstance Resumpton dstance Approach perpendcular to sensng axs Standard sensng object m Dstance to convergent pont: Wth the convergent reflectve type sensor or the mark sensor, senstvty s not proportonal to the settng dstance and the maxmum senstvty pont s at an ntermedate poston. Ths pont at whch the senstvty s maxmum s called the convergent pont and s specfed along wth the sensng range. Senstvty Sensng area : Convergent reflectve type : Dffuse reflectve type Repeatablty Response tme Sensng axs Repeatablty Approach along sensng axs Repeatablty The tme lag between a change n the sensng state and the turnng / of the sensng output. Sensng condton operaton t t t t Beamreceved Beamnterrupted t: Response tme The maxmum ambent lght ntensty that does not cause sensor malfuncton. It s expressed as the permssble lght ntensty at the lght recevng face. Convergent pont Settng dstance Ambent llumnance Illumnance meter Lght source Standard sensng object

9 GLOSSARY Term Descrpton Degree of protecton aganst water, human body and sold foregn materal. Protecton degree s specfed as per IEC (Internatonal Electrotechncal Commsson). IEC standard IP Second fgure... Protecton aganst water penetraton Frst fgure Protecton aganst human body and sold foregn materal Photoelectrc Protecton degree specfed by the frst fgure Frst Descrpton fgure No protecton Protecton degree specfed by the second fgure Second Descrpton fgure No protecton Inductve Proxmty Protecton Protecton aganst contact wth nternal lve parts by a human hand (" mm "1.969 n) Protecton aganst contact wth nternal lve parts by a human fnger ("12 mm ".472 n) Protecton aganst contact wth nternal lve parts by a sold object more than 2. mm.98 n n thckness or dameter Protecton aganst contact wth nternal lve parts by a sold object more than 1. mm.39 n n thckness or dameter " "1.969 "12 ".472 t 2. t.98 t 1. t No harmful effect due to vertcally fallng water drops No harmful effect due to water drops 1 fallng from a range 1 wder than the vertcal No harmful effect due to water drops fallng from a range 6 wder than the 6 vertcal No harmful effect due to water splashes from any drecton 1 6 Protecton aganst dust penetraton whch can affect operaton No harmful effect due to drect water jet from any drecton 6 Complete protecton aganst dust penetraton Note: The IEC standard prescrbes test procedures for each protecton degree gven above. The protecton degree specfed n the product specfcatons has been decded accordng to these tests No water penetraton due to drect water jet from any drecton No water penetraton due to mmerson n water under specfed condtons Usable durng mmerson n water at the specfed pressure Cauton Although the protecton degree s specfed for the sensor ncludng the cable, the cable end s not waterproof, and s not covered by the protecton specfed. Hence, make sure that water does not seep n from the cable end. Water should not seep n from here Sensng heght (Protectve heght) JEM standards (Standards of the Japan Electrcal Manufacturer s assocaton) IP67g Ths specfes protecton aganst ol n addton to IP67 protecton of IEC standards. It specfes that ol drops or bubbles should not enter from any drecton. Ths represents the range wthn whch sensng objects can be detected for the lght curtan and area sensor. The conventonal lght curtan (SF2-EH seres) and area sensor has a sensng heght (protectve heght) lmted to the heght from the bottommost end beam axs to the topmost end beam axs. 2 mm.787 n beam ptch <SF4-AH seres> Mnmum sensng object Lens"1 mm.394 n "3 mm "1.181 n 2 mm.984 n 2 mm.787 n Beam ptch Protectve heght: 19 mm 7.48 n <Conventonal model> Beam ptch 2 mm.787 n Sensng heght: 14 mm.12 n 1133

10 GLOSSARY Term Descrpton Term Descrpton Photoelectrc Inductve Proxmty Parallel devaton Angular devaton Sensng feld Correlaton between sensng object sze and sensng range The parallel devaton dagram of the thru-beam type and the retroreflectve type sensors represents the boundary wthn whch the recever wll effectvely see the emtted lght beam. The curves are plotted as a seres of operatng ponts at whch the sensor enters the beam receved condton when the emtter or the reflector moves from the left or the rght towards the recever at dfferent settng dstances (wth the senstvty adjuster at maxmum senstvty). The graph s useful to determne the tolerance on beam algnment and the span between adjacently mounted sensors. (Refer to p.113) (Note) Settng dstance L (m ft) Recever Left Center Rght Operatng pont?(mm n) Thru-beam type sensor type Retroreflectve sensor Emtter # L # The angular devaton dagram of the thru-beam type and the retroreflectve type sensors represents the angular range wthn whch the recever wll effectvely see the emtted lght beam. The curves are plotted as a seres of ponts representng the angle at whch the sensor enters the beam receved condton as the angle s gradually reduced by movng the sensor or the reflector towards the center axs from the left or the rght at dfferent settng dstances (wth the senstvty adjuster at maxmum senstvty). The graph s useful to fnd the tolerable msalgnment angle. (Note) Settng dstance L (m ft) Thru-beam type sensor Emtter $ L Recever Recever angular Retroreflectve type sensor devaton angular angular devaton devaton Emtter angular (RF-23) devaton (RF-23) 1 1 $ Left Center Rght L $ L Operatng angle$( ) The sensng feld dagram of the dffuse or the convergent reflectve type sensor represents the boundary wthn whch the sensor wll be operated by the reflected beam from the standard sensng object. The curves are plotted as a seres of operatng ponts at whch the sensor enters the beam receved state when the standard sensng object approaches from the left or the rght for dfferent settng dstances (wth the senstvty adjuster at maxmum senstvty). The graph s useful to determne the mountng poston of the sensor wth respect to the sensng object and the span between adjacently mounted sensors. (Refer to p.113) (Note) Reflectve type sensor Settng dstance L (mm n) Left Center Rght Operatng pont?(mm n) Ths dagram for the dffuse reflectve type sensor gves the correlaton between sensng object sze and sensng range. For sensors havng a senstvty adjuster, the graph s shown for the ( condton when the senstvty adjuster s set such that the standard ) sensng object s just detectable at the maxmum sensng dstance. The graph s useful to determne the sensng dstance for whch the sensor can stably detect an object consderng ts sze. (Note) Sensng range L (mm n) L L Standard sensng object Reflectve type sensor aa mm aa n Sensng object L Correlaton between lghtness and sensng range Correlaton between materal and sensng range Correlaton between color and sensng range Correlaton between settng dstance and excess gan Ths dagram of the convergent reflectve type sensor gves the correlaton between lghtness and sensng range. The graph s useful to determne the sensng dstance for whch the sensor can relably detect an object consderng ts lghtness. (Note) Sensng range L (mm n) Sensng range L (mm n) Sensng range L (mm n) Dark N2 Sensng regon N4 N6 N8 Lghtness Lght N1 N2N3N4NN6 N7 N8 N9 Ths dagram of the convergent or the fxed-focus reflectve type sensor gves the correlaton between object materal and sensng range. The graph s useful to determne the sensng dstance for whch the sensor can relably detect an object consderng ts materal. (Note) Mrror Glossy stanless steel Glossy copper plate Non-glossy alumnum plate Whte non-glossy paper Whte ceramc crcut board Glass epoxy PCB (green masked surface) Black panted ron (non-glossy) Gray non-glossy paper (N) Ths dagram of the convergent or the fxed-focus reflectve type sensor gves the correlaton between color and sensng range. The graph s useful to determne the sensng dstance for whch the sensor can relably detect an object consderng ts color. (Note) Whte Yellow Orange Red Brown Green Blue Gray Black Dstance to convergent pont Dstance to convergent pont 4 mm 1.7 n 3 mm n 2 mm.787 n These bars ndcate the sensng range wth the respectve colors when the dstance adjuster s set at the sensng range of 4 mm 1.7 n, 3 mm n and 2 mm.787 n long, each, wth whte color. Excess gan s a measurement of the sensng energy fallng on the recever of a sensng system over and above the mnmum amount requred to operate the sensor. Excess gan may be used to predct the relablty of any sensng system. (Note) 1 Excess gan 1 EX-13 EX-17 EX-11 EX , Settng dstance L (mm n) The sensng regon s represented by oblque lnes n the left fgure. However, the senstvty should be set wth enough margn because of slght varaton n products. ( ) Lghtness shown on the left may dffer slghtly from the actual object condton. The bars n the graph ndcate the sensng range for the respectve materal. However, there s a slght varaton n the sensng range dependng on the product. Further, f there s a reflectve object (conveyor, etc.) n the background of the sensng object, snce t affects the sensng, separate t by more than twce the sensng range shown n the left graph Sensng object sde length a (mm n) Note: These are typcal graphs, and are subject to slght changes from model to model. 1134

11 PRECAUTIS FOR PROPER USE Settng dstance Thru-beam type and retroreflectve type sensors The settng dstance must be equal to or less than the specfed sensng range. The sensors may be operable at a settng dstance longer than the rated sensng range, but relable operaton cannot be guaranteed. Further, n a drty or dusty envronment, the settng should provde margn for beam ntensty reducton. Countermeasure 1: Use sensors havng nterference preventon functon. When sensors havng the nterference preventon functon are used, two sensors can be mounted close together. In case of the PX-2 seres: 26 sensors, SF2-EH seres: 12 sensors, FX-32: 8 sensors, SF2-N seres: 6 sensors, FX-31 seres and FX-311 seres: 4 sensors, SF4-AH seres and NA1-PK3 seres: 3 sensors can be mounted close together. ( ) Lst of photoelectrc sensors havng nterference preventon functon Photoelectrc Reflectve type sensors The sensng range gven n the specfcatons s for the standard sensng object. Snce the actual sensng dstance dffers wth the sze, color, surface condton, etc., of the sensng object, set the sensor gvng enough margn for these dfferences. Change of sensng range wth sensng object sze The bgger the sensng object sze, the larger the quantty of lght reflected, whch ncreases the sensng range. However, f the sensng object becomes bgger than the spread of the lght beam or the feld of vson of the recever, the sensng range does not ncrease any further. Sensng range Sensng object sze (area) Change of sensng range wth sensng object (Dffuse reflectve type sensors) Relatve sensng range (%) A : Whte non-glossy paper (Standard) B : Natural color cardboard C: Plywood D: Black non-glossy paper (Lghtness: 3) A B C D E F G H I J K L E : Plywood (glossy) Bakelte board (Natural color) Acrylc board (Black) Vnyl leather (Red) F: Vnyl leather (Gray) G: Rubber sheet (Green glossy) Standard sensng object H: Alumnum sheet I : Reflex reflector J: "1 mm ".394 n rusted steel rod " mm ".197 n brass ppe K : Cloth (Black) L : Cloth (Dark blue) Seres name Automatc nterference preventon FX-31 FX-32 FX-311 FX-7 CX-4 (Excludng thru-beam type sensors) SU-7 CX-2 Excludng thru-beam type sensors SF2-N ( ) and retroreflectve type sensors for SF1-N transparent object sensng SF1-F EQ-2 EQ- EQ-3 NA1-PK/ RX Excludng thru-beam type SF1-P ( sensors and RX-LS2 ) NX (Excludng thru-beam type sensors) SS-A PX-2 BRX Retroreflectve type and dffuse ( reflectve type sensors only ) CX (Excludng thru-beam type sensors) CX-3 (Retroreflectve type only) Interference preventon (wth frequency selecton swtch) FX-11A SF4-AH SF2-EH NA4 NA2-N NA1-PK3 BFX4N Notes: 1) For the thru-beam type sensors ncorporated wth a senstvty adjuster, reduce the senstvty to a level at whch the stablty ndcators just lght up. Notes: 2) When two dffuse reflectve type sensors face each other, tlt them down. $ $ Countermeasure 2: Use nterference preventon flters. Interference preventon flters are avalable for CX-411, NX-M1RA and NX-M1RB. <NX-M1RA, NX-M1RB> One set of PF-NX-H ftted (Interference preventon flters) One set of PF-NX-V ftted (Interference preventon flters) Countermeasure 3: Increase the separaton dstance. Fnd out the operatng pont Parallel devaton? 1 on the parallel devaton dagram or the sensng feld dagram for the settng dstance L1. Separate sensors L1 by 2? 1 or more. Settng dstance L Inductve Proxmty The above mentoned relatve sensng range for dfferent sensng objects has been gven takng the sensng range for whte non-glossy paper as 1. The values are gven for reference, and would vary slghtly wth the type of photoelectrc sensor, sensng object sze, etc. Emtter Emtter Recever Recever #1 Left Center Operatng pont? Rght #12 or more Mountng Mutual nterference If sensors are mounted adjacently, they may affect each other s operaton (mutual nterference). The followng countermeasures are necessary to prevent t. Emtter Recever #12 or more L1 113

12 Photoelectrc Inductve Proxmty PRECAUTIS FOR PROPER USE Countermeasure 4: Place the emtter and the recever alternately. (Thru-beam type sensors only) Emtter Recever Recever Emtter Wth ths arrangement, f a sensng object comes near the sensors, the beam reflected from the sensng object may enter the recever as shown below. In ths case, countermeasures, such as placng a sheld between the emtter and the recever are necessary. Emtter Recever Placng a sheld Emtter Sheld Sensng object Sensng object Recever Emtter Recever Sheld Recever Emtter Countermeasure : Narrow the lght beam wth a hood or a slt mask. (Thru-beam type sensors only) Emtter hood Influence of surroundngs hood Thru-beam type and retroreflectve type sensors Recever If a thru-beam type sensor, or a retroreflectve type sensor s mounted on a flat shny plane, the emtted beam may not be nterrupted by a sensng object because some amount of the emtted beam passes through the gap between the sensng object and the plane, gets reflected from the plane, and enters the recever. Emtter or retroreflectve type sensor Beam axs Sensng object Recever or reflector Countermeasure 1: Increase dstance from the mountng plane. Mountng plane Countermeasure 2: Pant the mountng plane n non-glossy black color. Influence of background If there s a wall, etc., behnd the sensng object, the sensor operaton may be affected. Countermeasures: Remove the background. Pant the background n black color. Increase the dstance from the background. Use a fxed-focus sensor or a convergent reflectve sensor. Influence of extraneous lght Most of the sensors use modulated beam hghly mmune to sunlght or ordnary fluorescent lght. However, ntense lght or lght from nverter fluorescent lamps may affect the sensor operaton. The CX seres s ncorporated wth an nverter fluores- ( ) cent lght resstant crcutry. Countermeasure 1: Tlt the beam axs so that the recever s not drectly facng the extraneous lght source. Recever Emtter 3 or more Note that the sunlght ncdence angle vares wth the season. Countermeasure 2: Attach a hood on the recever. Extraneous lght source Extraneous lght source Background Mountng plane Countermeasure 1: Increase dstance from the mountng plane. Emtter or retroreflectve type sensor Sensng object Mountng plane Recever or reflector Countermeasure 2: Place lght barrers on the mountng plane. Emtter or retroreflectve type sensor Beam axs Sensng object Recever or reflector Recever Emtter Beam algnment (Thru-beam type and retroreflectve type sensors) 1 Placng the emtter and the recever face to face along a straght lne, move the emtter n the up, down, left and rght drectons, n order to determne the range of the beam receved condton wth the help of the operaton ndcator. Then, set the emtter at the center of ths range. 2 Smlarly, adjust for up, down, left and rght angular movement. 3 Further, perform the angular adjustment for the recever also. 4 Fnally check that the stablty ndcator lghts up. A Mountng plane B Place lght barrers b and c to prevent reflecton. Countermeasure 3: Pant the mountng plane n non-glossy black color. C Reflectve type sensors Effect of mountng plane If a reflectve type sensor Mountng plane s mounted on a rough plane, scatteredly reflected beam returns to the sensor. Ths causes the hysteress to ncrease or the sensor to always reman n the lght receved condton Emtter Recever Perform the beam algnment wth a retroreflectve type sensor, smlarly. Normally, the mrror angle can be set roughly, but the sensor angle must be precsely adjusted.

13 PRECAUTIS FOR PROPER USE Senstvty adjustment Follow the procedure gven below whle notcng the operaton ndcator. 1 Turn the senstvty adjuster fully counterclockwse to the mnmum senstvty poston. 2 In the lght receved condton, turn the senstvty adjuster slowly and confrm the where the sensor enters the Lght state operaton. 3 In the dark condton, turn the senstvty adjuster further clockwse untl the sensor enters the Lght state operaton and then brng t back to confrm pont b where the sensor just returns to the Dark state operaton. If the sensor does not enter the Lght state operaton ( even when the senstvty adjuster s turned fully) clockwse, ths extreme poston s pont b. 4 The poston at the mddle of and b s the optmum sensng poston. Turn the adjuster wth the accessory screwdrver. ( The adjuster may be damaged f t s turned beyond ) ts lmt wth excessve force. Thru-beam Retroreflectve Reflectve n the lght receved condton A Mn. Detectable Optmum senstvty range Senstvty adjuster n the dark condton B Max. n the dark condton Lght receved condton Dark condton Presence detecton Lght ntensty detecton Presence detecton Lght ntensty detecton Presence detecton Mark sensng Green beam Red beam Emtter Emtter Sensng object Sensng object Recever Recever Sensng object Sensng object (Whte / Yellow / Orange / Red) Sensng object (Whte / Yellow / Orange) Emtter Emtter Sensng object Sensng object Sensng object Sensng object Recever Recever Sensng object (Black / Blue / Green) Sensng object (Black / Blue / Green / Red) The FX-31/32/33 seres, FX-7 seres, FZ-1 seres and SU-7 seres ncorporate an automatc senstvty settng functon, whch allows senstvty settng just by pressng buttons. For these seres, there s no need to follow the above adjustment procedure. Color dscrmnaton durng mark sensng Marks can be sensed wth color fber sensor FZ-1 seres, mark sensor or fber sensor. The FZ-1 seres uses red, green and blue LEDs to dentfy a color by ts three color components. Hence, t s able to dscrmnate even mnute color dfferences. For mark sensors and fber sensors, the color combnatons of the mark and the background whch can be dscrmnated, dependng on the color of the lght source, are as gven n the table below. Mark Background color color Whte Yellow Orange Red Green Blue Black Whte b b gb rgb rgb rgb Yellow b g g rgb rgb rgb Orange b g gb rgb rgb rgb Red gb g gb r rb rb Green rgb rgb rgb r b b Blue rgb rgb rgb rb b b Black rgb rgb rgb rb b b r: Red LED type g: Green LED type b: Blue LED type Other precautons Although the protecton degree s specfed for the sensor ncludng the cable, the cable end s not waterproof and s not covered by the protecton specfed. Hence, make sure that water does not seep n from the cable end. Make sure that the power s off whle wrng. Verfy that the voltage varaton s wthn the ratng. If power s suppled from a commercal swtchng regulator, ensure that the frame ground (F.G.) termnal of the power s connected to an actual ground. F.G.termnal Water should not seep n from here Ground Swtchng regulator In case nose generatng equpment (swtchng regulator, nverter motor, etc.) s used n the vcnty of ths product, connect the frame ground (F.G.) termnal of the equpment to an actual ground. Hgh-voltage lne or Do not run the wres together power lne wth hgh-voltage lnes or power lnes or put them n the same raceway. Ths can cause malfuncton due to nducton. Avod dust, drt, and steam. Take care that the sensor does not come n drect contact wth water, ol, grease or organc solvents, such as, thnner, etc. Take care that the sensor s not drectly exposed to fluorescent Fluorescent lamp lamp from a rapd-starter lamp or a hgh frequency lghtng devce, as t may affect the sensng performance. These sensors are sutable for ndoor use only. Make sure that stress s not appled drectly to the sensor cable jont. AC F.G Photoelectrc Inductve Proxmty

14 Photoelectrc Inductve Proxmty PRINCIPLES OF PARTICULAR OPTICAL SENSING SYSTEMS Fber cables Prncple of optcal fber An optcal fber comprses of a core and a claddng, whch have dfferent refractve ndexes. When lght s ncdent on the core, t propagates n the core by beng totally reflected at the boundary between the core and the claddng. After travelng through the fber, lght spreads at an angle of approx. 6 at the cable end and s drected on the sensng object. LED Optcal fber 6 approx. Core (hgher refractve ndex) Claddng (lower refractve ndex) Retroreflectve type sensor wth polarzng flters Prncple Opposte types of polarzng flters are placed n front of the emttng and recevng s. A horzontal polarzng flter placed n front of the emttng passes only horzontally polarzed lght and a vertcal polarzng flter placed n front of the recever ensures that only vertcally polarzed lght s receved. Usng ths confguraton, even specular objects can be relably detected. 1 Normal unpolarzed beam emtted from the LED oscllates n a random manner. As t passes through the horzontal polarzng flter, the oscllaton s algned horzontally and the beam s horzontally polarzed. 2 When the polarzed beam falls on the reflector, ts polarzaton s destroyed and the reflected beam oscllates n a random manner. So, the reflected beam can pass through the vertcal polarzng flter and reach the recevng. Vertcal polarzng flter Recevng s of fber cables and ther features Plastc Glass Fber cable structure Features The fber s made of acrylc. The cable may consst of a sngle or multple fber strands of ".12 ". to "1. mm ".9 n. It s wdely used because of ts low prce. The sharp bendng fber s made up of several hundred ".7 mm ".3 n acrylc resn fbers bound together nto a sngle mult-core fber, so that t can be bend at rght angles wthout causng a decrease n lght ntensty or breakng. The fber s made of glass that provdes better heatresstance and chemcal-resstance than plastc. The cable conssts of multple fber strands of ". mm ".2 n. It s used manly for specal applcatons because of ts hgh prce. Fber sensors are classfed broadly nto two groups thrubeam type and reflectve type. The thru-beam type has two fber cables: the emttng cable and the recevng cable. The reflectve type has one fber cable that contans, both, the emttng part and the recevng part. The cable can be classfed nto parallel, coaxal or partton types, dependng on the structural arrangement of the fber strands. Cable structure Parallel Descrpton Generally used for plastc fber cables. Horzontal polarzng flter Emttng However, a specular object does not destroy the polarzaton. The reflected beam oscllates horzontally, as before, and cannot pass through the vertcal polarzng flter. Specular object Horzontal polarzng flter Vertcal polarzng flter Recevng Adjustable range & fxed-focus reflectve type photoelectrc sensor Employng the optcal trangulaton method, t relably senses an object at a gven dstance, rrespectve of ts reflectvty, by measurng the angle of the receved beam. It contans an emttng lens and a recevng lens. The beam from the emttng lens falls on the sensng object and, after beng reflected, s guded by the recevng lens onto a 2-segment dode. Here, the sensng object dstance s determned by takng the poston at whch the upper and lower segments of the 2-segment photodode generate equal output voltages as the reference. Ths method, besdes beng sutable for long dstance, s also good for hgh accuracy poston algnment. Further, the equal output voltages are obtaned by adjustng the poston of the recevng lens. Dstance adjuster Emttng Coaxal Partton 1138 The center fber s for beam emsson, and the surroundng fbers are for recevng the beam. Ths structure s sutable for hgh accuracy measurements snce the sensng poston does not change wth the travel drecton of the sensng object. Generally used for glass fber cable. It comprses of a number of glass fber strands of ". mm ".2 n, and s dvded nto the emttng part and the recevng part. Sensng object Recevng lens (Non-sphercal lens) Emttng lens (Non-sphercal lens) 2-segment photodode Moves up or down Infrared LED The EQ-2 seres uses a PSD (Poston Sensng Devce) as the recevng.

15 PRINCIPLES OF PARTICULAR OPTICAL SENSING SYSTEMS Color sensor Three LEDs, red, green and blue, are used as the emttng s. Each of them emt n turn to llumnate the sensng object and the color components of the reflected beam are processed to determne the sensng object color. Red LED Green LED Blue LED Half mrrors Lens Fber cables Cross-beam scannng Ths s a modfed type of lght curtan. Although the emtter and the recever each consst of an array of s, only the emttng s are scanned and lght from one emttng s receved by all the recevng s. If lght s not receved even by one recevng, t results n lght nterrupted state. Hence, even thn objects, such as postcards, can also be detected A Scannng Emtter NA1-11 Lqud level detecton sensor (ppe-mountable type) Thru-beam type A Recever Non-Scannng Scannng When lqud s present, the lens focuses as per the lqud lens effect and the beam s receved. <Flled ppe> <Empty ppe> General purpose area sensor Emtter Recever Scannng Lqud level detecton fber (Contact type) When the fber tp s n the ar, as there s a large dfference between the ar and the tube refractve ndexes, the tube boundary reflects the emtted beam back to the recever. On the other hand, when the fber tp s mmersed n a lqud, the emtted beam scatters from the fber nto the lqud because of the small dfference n the lqud and the tube refractve ndexes. Ar Lqud In the ar Fber Tube Ar Lqud In lqud Leak lqud detecton (Leak detecton fber / Leak detecton sensor) The unque effect of capllarty enables relable detecton of small leaks and vscous lquds. Capllarty effect Lqud Leakage pan New of Detecton Method head When a leak occurs, the beam from the beam-emttng part scatters through the leaked lqud and s not transmtted to the beam-recevng part. Photoelectrc Inductve Proxmty The lens focuses as per the lqud lens effect and the beam s receved. The beam s scattered and not receved. Reflectve type When the ppe s empty, the beam s reflected from the nner surface of the ppe wall and returns to the beamrecevng part snce the dfference n the refractve ndexes of the ppe and ar s large. When there s lqud n the ppe, the beam enters the lqud through the wall and does not return to the beam-recevng part as the dfference n the refractve ndexes of the ppe and the lqud s small. <Empty ppe> <Flled ppe> When leakage occurs The beam from the beam-emttng part scatters through the leaked lqud and s not transmtted to the beam-recevng part. Beam-emttng part Leaked lqud Leakage pan Beam-recevng part Sensng surface When there s no leakage The beam from the beam-emttng part reflects off of the surface of the sensor and s transmtted to the beamrecevng part. Beam-emttng part Beam-recevng part The beam reflected from the nner surface of the ppe wall returns to the beam-recevng part. The beam passes through the wall nto the lqud. Leakage pan Sensng surface 1139

16 Photoelectrc FUNCTIS Functon Descrpton The sensor dagnoses the ncdent lght ntensty, and f t s reduced due to dust or drt, or beam msalgnment, a vsual ndcaton and/or an output s generated. Drt Beam msalgnment Functon Descrpton Senstvty settng s done smply by pressng a button. Press the jog swtch wth the object n front of the fber. Inductve Proxmty Self-dagnoss functon Tme chart Sensng condton Sensng output (operaton ndcator) (n the Lght- mode) Stablty ndcator Self-dagnoss output Insuffcent beam ntensty 1 Insuffcent beam nterrupton Stable lght receved level Sensng output threshold level Stable dark level (Lghts up) (Lghts off) Lghts up Lghts off 1 The self-dagnoss output transstor stays n the state ( state n case of SS-A) durng stable sensng. 2 When the sensng output changes, f the ncdent lght ntensty does not reach the stable lght receved level or the stable dark level, the self-dagnoss output becomes ( n case of SS-A). Further, the self-dagnoss output changes state when the sensng output changes from Lght to Dark state. (It s not affected by the operaton mode swtch.) 3 In case of nsuffcent beam nterrupton, there wll be a tme lag before the self-dagnoss output turns. The SF4-AH seres, SF2-A seres, SF2-N seres, SF2-EH seres, etc., have a self-dagnoss functon for the nternal crcutry besdes the above mentoned self-dagnoss functon for the beam ntensty. Snce the tme chart dffers wth the sensor model, please refer to the secton PRECAUTIS FOR PROPER USE of the respectve sensor seres. Incdent lght ntensty can be dsplayed numercally or by an LED array. FX-31 Incdent lght ntensty can be shown on a dgtal dsplay (4 dgt LED). Automatc senstvty settng External synchronzaton functon Press the jog swtch wthout the object. Blue LED, green LED, nfrared LED type of the FX-31 seres feature a full auto-teachng functon by whch senstvty settng can be done on a movng object wthout stoppng the assembly lne. Further, n case of the FZ-1 seres and SU-7 seres, senstvty settng s done by usng a button swtch. The tmng of sensng can be controlled. Tme chart (wth SU-7) Sensng sgnal External sync. nput Sensng output Hgh Low Edge trgger T 4ms approx. Applcaton Checkng orentaton of IC Hgh Low Gate trgger T j.6 ms (when the nterference preventon functon s used, T j.8 ms) Notch detecton sensor Sensng output External synchronzaton sgnal nput T Synchronzng sensor Lght ntensty montor Infrared or red beam type of thru-beam photoelectrc sensors Usng the optonal sensor checker CHX-SC2, the ncdent lght ntensty can be checked audo-vsually. Emtter checker CHX-SC2 POWER CHX-SC2 LEVEL Level ndcator Interference preventon functon When several photoelectrc sensors are mounted close together, mutual nterference can be prevented by settng dfferent emsson frequences. Interference preventon functon by whch the emsson frequency can be changed by a swtch or an nterference preventon wre, or, automatc nterference preventon functon by whch the frequency s automatcally changed by the sensor are avalable. Applcaton Checkng orentaton of workpece Detectng IC pns 114

17 FUNCTIS Functon Descrpton Functon Descrpton The stablty ndcator (green) lghts up when the ncdent lght ntensty has suffcent margn wth respect to the operaton level. If the ncdent lght ntensty level s such that the stablty ndcator lghts up, stable sensng can be done wthout the lght receved operaton and the lght nterrupted operaton beng affected by a change n ambent temperature or voltage. Operaton of stablty ndcator The senstvty s adjusted accordng to the settng dstance to mantan the optmum senstvty. Photoelectrc Stablty ndcator Incdent lght margn operaton level Lght nterrupton margn 1% approx. 2% approx. Lghts up Lghts up Lghts off Settng dstance In case of the NA2-N seres, NA1-PK/ seres and NA1-PK3 seres, ths s the stable ncdent beam ndcator and lghts up when the ncdent lght margn s exceeded. The wdth of the output sgnal s controlled to match the connected devce specfcatons. -delay Functon: Neglects short output sgnals. Applcaton: As only longer sgnals are extracted, ths functon s useful for detectng f a lne s clogged, or for sensng only objects takng a long tme to travel. (e.g.) Sensng of jammng n an assembly lne -delay Functon: Extends the output sgnal for a fxed perod of tme. Applcaton: Ths functon s useful f the output sgnal s so short that the connected devce cannot respond. Lght receved operaton Lght nterrupted operaton operaton 1 Incdent lght ntensty (%) Automatc senstvty compensaton functon The senstvty s reduced f the emtter and the recever are brought closer. The senstvty s ncreased n case of dust or drt. The emsson can be stopped by an external test nput. Applcaton Start-up nspecton Inductve Proxmty E SHOT Tmer functon Functon: s a fxed wdth sgnal upon sensng Applcaton: Ths functon s useful when the nput specfcatons of the connected devce requre a sgnal of fxed wdth. Of course, t s also useful for extendng a short wdth sgnal to a desred wdth. Tme chart T: Tmer perod Sensng Beamreceved condton Beamnterrupted Operaton Lght- normal operaton Lght- T -delay Lght- T T T -delay Lght- E SHOT Dark- normal operaton Dark- -delay Dark- -delay Dark- E SHOT T T The FX-32 s equpped wth an -delay / -delay tmer that allows you to use -delay and -delay smultaneously as well as an -delay / E SHOT tmer enablng a smultaneous -delay and E SHOT. T T T T T T T T Test nput (emsson halt nput) Tme chart Test nput emsson halt nput ( ) Sensng output n the Dark- ( mode ) Test nput V Hgh Low PLC, Swtch, etc. Normal Abnormal When several sensors are arrayed n a lne, ths functon can also be used for mutual nterference preventon by controllng the beam emsson n a cyclc manner. 1141

18 Inductve Proxmty Photoelectrc FX-31 FX-32 FX-33 FX-311 FX-11A FZ-1 CX-4 EX-3 EX-2 EX-1 EQ-2 EQ-3 EX-4 RX RX-LS2 CY PX-2 RT-61 PM PM2 NX VF EQ- SU-7/SH SS-A Dgtal settng Manually set Analog output Color detecton Amplfer bult-n Mcro Power bult-n Fber sensors Photoerectrc sensors Item Amplferseparated Selfdagnoss Lght ntensty montor Seres name Lght ntensty Internal crcut Dgtal dsplay LED array & buzzer Automatc senstvty settng External sync. Edge trgger Gate trgger (Note) (Note) (Note) (Note) (Note) (Note) (Note) (Note) (Note) (Note) Interference preventon Stablty ndcator -delay -delay E SHOT Tmer -delay / -delay -delay / E SHOT Automatc senstvty compensaton Test nput Note: By usng sensor checker CHX-SC2. SF4-AH SF2-A SF2-N SF2-EH SF1-F NA2-N Lght curtans for safeguard Indvdual beam outputs FUNCTIS Functon avalablty table : All models g: Some models 1142 NA1-11 NA1-PK/ NA1-PK3 M-DW1 FT-K FD-L43 FD-L41/L42 SH-72 M HD-T1 EX-F7/F6 FD-F7 FT-F9 FX-31-F EX-F1 FD-F4/F9 FD-F8Y FT-Z8Y Slm body Pckng Area sensors for semconductor ndustry Glass substrate / wafer sensng Leak lqud / Lqud level sensng FT-L8Y/V8Y Chemcal-resstant FD-H3-L32, FD-H18-L31 EZ-1 Heat-resstant Water detecton Partcular use sensor 1143