GRTE18-N1147型(xing)德(de)國(guó)SICK西克(ke)光電(dian)傳(chuan)感(gan)器的(de)工(gong)作(zuo)原(yuan)理:
由光通(tong)量對(duì)光電(dian)元(yuan)件的作(zuo)用(yong)原(yuan)理不同(tong)所制(zhi)成的(de)光學(xué)(xue)測(cè)(ce)控(kong)系(xi)統(tǒng)是多種(zhong)多(duo)樣(yang)的(de),按(an)光電(dian)元(yuan)件(光學(xué)(xue)測(cè)(ce)控(kong)系(xi)統(tǒng))輸(shu)出(chu)量性(xing)質(zhì)可(ke)分二(er)類(lei),即模(mo)擬式(shi)德(de)國(guó)SICK西克(ke)光電(dian)傳(chuan)感(gan)器和(he)脈(mai)沖(chong)(開(kāi)關(guān))式德國(guó)SICK西克(ke)光電(dian)傳(chuan)感(gan)器。模(mo)擬式(shi)德(de)國(guó)SICK西克(ke)光電(dian)傳(chuan)感(gan)器是將被(bei)測(cè)(ce)量轉(zhuǎn)(zhuan)換(huan)成連續(xù)變(bian)化的光電(dian)流,它與被(bei)測(cè)(ce)量間呈單(dan)值(zhi)關(guān)(guan)系(xi).模(mo)擬式(shi)德(de)國(guó)SICK西克(ke)光電(dian)傳(chuan)感(gan)器按(an)被(bei)測(cè)(ce)量(檢(jian)測(cè)(ce)目標(biāo)(biao)物(wu)體(ti))方(fang)法可(ke)分為(wei)透(tou)射(吸(xi)收(shou))式(shi),漫(man)反射式,遮光式(光束阻(zu)檔(dang))三(san)大類。所謂(wei)透射(she)式(shi)是指(zhi)被(bei)測(cè)(ce)物(wu)體(ti)放(fang)在(zai)光路(lu)中(zhong),恒(heng)光源(yuan)發(fā)出(chu)的(de)光能量穿(chuan)過(guò)被(bei)測(cè)(ce)物(wu),部(bu)份被(bei)吸收(shou)後,透射(she)光投射到(dao)光電(dian)元(yuan)件上(shang);所謂(wei)漫反(fan)射(she)式(shi)是指(zhi)恒(heng)光源(yuan)發(fā)出(chu)的(de)光投射到(dao)被(bei)測(cè)(ce)物(wu)上(shang),再?gòu)谋?bei)測(cè)(ce)物(wu)體(ti)表(biao)面反射後投射(she)到(dao)光電(dian)元(yuan)件上(shang);所謂(wei)遮光式是指(zhi)當(dāng)(dang)光源(yuan)發(fā)出(chu)的(de)光通(tong)量經(jīng)(jing)被(bei)測(cè)(ce)物(wu)光遮其中(zhong)壹部(bu)份(fen),使投射到(dao)光電(dian)元(yuan)件上(shang)的光通(tong)量改(gai)變,改(gai)變的(de)程度與被(bei)測(cè)(ce)物(wu)體(ti)在(zai)光路(lu)位置(zhi)有(you)關(guān)。
光敏二極管是最常(chang)見(jiàn)(jian)的光傳(chuan)感(gan)器。光敏二極管的外(wai)型(xing)與壹般(ban)二(er)極(ji)管壹樣(yang),當(dāng)(dang)無(wú)光照時(shí)(shi),它(ta)與普(pu)通(tong)二極管壹樣(yang),反(fan)向電(dian)流很小,稱為(wei)光敏二極管的暗(an)電(dian)流;當(dāng)(dang)有光照時(shí)(shi),載(zai)流子被(bei)激發(fā),產(chǎn)(chan)生電(dian)子-空(kong)穴(xue),稱為光電(dian)載流子。在(zai)外(wai)電(dian)場(chǎng)(chang)的作(zuo)用(yong)下,光電(dian)載流子參(can)與導(dǎo)(dao)電(dian),形(xing)成比暗(an)電(dian)流大得多(duo)的(de)反向電(dian)流,該(gai)反向電(dian)流稱為(wei)光電(dian)流。光電(dian)流的大小與光照強(qiáng)(qiang)度成(cheng)正(zheng)比,於(yu)是在(zai)負(fù)載(zai)電(dian)阻(zu)上(shang)就(jiu)能得到(dao)隨(sui)光照強(qiáng)(qiang)度變(bian)化而變(bian)化的電(dian)信號(hào)(hao)。
光敏三極管除(chu)了具(ju)有(you)光敏二極管能將光信號(hào)轉(zhuǎn)(zhuan)換(huan)成電(dian)信號(hào)(hao)的(de)功能外(wai),還有(you)對(duì)電(dian)信號(hào)(hao)放(fang)大的功能。光敏三級(jí)管的外(wai)型(xing)與壹般(ban)三(san)極(ji)管相差不(bu)大,壹般(ban)光敏三極管只引(yin)出(chu)兩(liang)個(gè)(ge)極(ji)——發(fā)(fa)射(she)極和集電(dian)極,基(ji)極不(bu)引(yin)出(chu),管殼同(tong)樣(yang)開(kāi)(kai)窗(chuang)口(kou),以(yi)便光線(xian)射(she)入。為增(zeng)大光照,基(ji)區(qū)(qu)面(mian)積(ji)做得(de)很(hen)大,發(fā)射(she)區(qū)(qu)較(jiao)小,入射(she)光主要被(bei)基(ji)區(qū)(qu)吸(xi)收(shou)。工(gong)作(zuo)時(shí)集(ji)電(dian)結(jié)反偏(pian),發(fā)(fa)射結(jié)正(zheng)偏。在(zai)無(wú)光照時(shí)(shi)管子流過(guò)的(de)電(dian)流為暗(an)電(dian)流Iceo=(1+β)Icbo(很?。纫及?ban)三(san)極(ji)管的穿(chuan)透(tou)電(dian)流還??;當(dāng)(dang)有光照時(shí)(shi),激發(fā)大量的(de)電(dian)子-空(kong)穴(xue)對(duì),使得基(ji)極產(chǎn)(chan)生的電(dian)流Ib增(zeng)大,此刻(ke)流過(guò)管子的(de)電(dian)流稱為(wei)光電(dian)流,發(fā)射(she)極(ji)電(dian)流Ie=(1+β)Ib,可見(jiàn)(jian)光電(dian)三極(ji)管要比光電(dian)二極(ji)管具(ju)有(you)更(geng)高的(de)靈(ling)敏度。
德國(guó)SICK西克(ke)光電(dian)傳(chuan)感(gan)器在(zai)壹般(ban)情(qing)況下,有(you)三部(bu)分構(gòu)(gou)成(cheng),它們(men)分為(wei):發(fā)(fa)送器、接(jie)收(shou)器和(he)檢(jian)測(cè)(ce)電(dian)路(lu)。發(fā)送器對(duì)準(zhǔn)目標(biāo)(biao)發(fā)(fa)射光束,發(fā)(fa)射的(de)光束壹般(ban)來(lái)(lai)源(yuan)於(yu)半(ban)導(dǎo)體(ti)光源(yuan),發(fā)光二極管(LED)、激光二極管及紅(hong)外(wai)發(fā)射(she)二極(ji)管。光束不(bu)間斷(duan)地發(fā)(fa)射(she),或(huo)者(zhe)改(gai)變(bian)脈(mai)沖寬(kuan)度。接(jie)收(shou)器有(you)光電(dian)二極(ji)管、光電(dian)三極(ji)管、光電(dian)池組(zu)成(cheng)。在(zai)接(jie)收(shou)器的(de)前(qian)面,裝(zhuang)有光學(xué)(xue)元(yuan)件如透(tou)鏡(jing)和光圈(quan)等(deng)。在(zai)其後面是檢測(cè)(ce)電(dian)路(lu),它能濾出(chu)有(you)效信號(hào)和應(yīng)用(yong)該(gai)信號(hào)。
德(de)國(guó)SICK西克(ke)光電(dian)傳(chuan)感(gan)器壹般(ban)由處(chu)理通(tong)路(lu)和處(chu)理元(yuan)件2 部分組(zu)成(cheng)。其基(ji)本原(yuan)理是以光電(dian)效應(yīng)為基(ji)礎(chǔ),把(ba)被(bei)測(cè)(ce)量的(de)變化轉(zhuǎn)(zhuan)換(huan)成光信號(hào)的(de)變化,然(ran)後借(jie)助光電(dian)元(yuan)件進(jìn)(jin)壹步(bu)將(jiang)非(fei)電(dian)信號(hào)(hao)轉(zhuǎn)(zhuan)換(huan)成電(dian)信號(hào)(hao)。光電(dian)效應(yīng)是指(zhi)用(yong)光照射(she)某(mou)壹物(wu)體(ti),可(ke)以看作是壹連串帶(dai)有(you)壹定能量為(wei)的光子轟(hong)擊在(zai)這個(gè)物(wu)體(ti)上(shang),此時(shí)(shi)光子能量就(jiu)傳(chuan)遞(di)給(gei)電(dian)子,並(bing)且(qie)是壹個(gè)(ge)光子的(de)全(quan)部能量壹次(ci)性(xing)地被(bei)壹個(gè)(ge)電(dian)子所吸(xi)收(shou),電(dian)子得(de)到(dao)光子傳(chuan)遞(di)的能量後其狀態(tài)就(jiu)會(huì)(hui)發(fā)(fa)生變化,從而(er)使(shi)受光照射(she)的(de)物(wu)體(ti)產(chǎn)(chan)生相應(yīng)的電(dian)效應(yīng)。通(tong)常把光電(dian)效應(yīng)分為(wei)3 類(lei):(1 )在(zai)光線(xian)作(zuo)用(yong)下能使電(dian)子溢(yi)出(chu)物(wu)體(ti)表(biao)面的現(xiàn)(xian)象稱為外(wai)光電(dian)效應(yīng),如光電(dian)管、光電(dian)倍(bei)增(zeng)管等;(2 )在(zai)光線(xian)作(zuo)用(yong)下能使物(wu)體(ti)的(de)電(dian)阻(zu)率(lv)改(gai)變(bian)的(de)現(xiàn)(xian)象稱為內(nèi)光電(dian)效應(yīng),如光敏電(dian)阻(zu)、光敏晶體(ti)管等;(3 )在(zai)光線(xian)作(zuo)用(yong)下,物(wu)體(ti)產(chǎn)(chan)生壹定方向電(dian)動(dòng)勢(shì)(shi)的(de)現(xiàn)(xian)象稱為光生伏效應(yīng),如光電(dian)池等(deng)。
實(shí)物(wu)如(ru)下圖所示(shi):
