CONG NGHE QNG DUNG Trong thap nien dau cua the ky , LED (Light Emitting Diode - Oidt phat quang) co sir phat trien vircft bac Vol UU diem ctf ban la than thien mdi trtftfng, khdng sir dung hoa chat doc hai, khdng gay hieu ting nha kinh, co ben ctf hoc cao va dac biet t u o i tho rat cao nen LED dang dan thay the den huynh quang chieu sang noi t h a t Nhieu t o hop ma tran LED da da dtftfc ting dung chieu sang dtftfng giao t h o n g Dac biet chieu sang trang t r i , quang cao va le hoi LED t o Uu diem vtftft t r d i so voi cac nguon sang kinh dien va dang la cac phan chi'nh chieu sang cac cdng t r i n h kien true Bai viet sau day diem qua cac t t f u linh vtfc L E D N G U N S I S A N G E U C U A S H I E N A N T A I V A G T U O N G L A I PGS LE VAN DOANH - KS LE TRUNG KIEN Tri/gngDHBKHa SUPER B R I G H T LED, L I G H T SOURCE OF PRESENT A N D FUTURE In the first decade of the 21st century, LEDs (Light Emitting Diode) have a great development Because of its basic advantages as harmony with environment, non-toxic chemical, no greenhouse effect, high mechanical strength and longevity, LEDs are gradually replacing fluorescent lamps in interior light A lot of LEDs matrix combination has already been used in road lighting Especially in decoration, advertisement and festival, LEDs show outstanding advantages compared to other classical sources of light and are the main ingredient in building illumination 12 Tir ddng hoa / 12 2010 SO L U O C VE CAC N G U O N S A N G Thdi dai anh sang dien bat dau t d den spi dot cua Thomas Edison (1837-1931) che tao vao nam 1879 tdso cac bon, tao nen nhiet dp 3900 K, hieu qua anh sang lm/W,tuoi thp 600 gid Nam 1908 nha khoa hoc Ddc Em: Werner Siemens (1816-1902) da sd dung soi dot vonfram-nicken keo dai tuoi tho cua den soi dot Cac den soi dot hien dai mdi trudng halogen co chi so the hien mau xap xi 100, cho anh sang am va dat hieu qua 20 Im/W Ho quang thuy ngan dupe phat hien t d nam 1901 nhung 30 nam sau mdi dupe dng dung thpc te.Tu nam 1960 cac den phong dien thuy ngan mdi dupe dng dung chieu sang cong cong, chung co the chuyen hoa 20% dien nang quang nang va la nguon sang lanh Hien tuong ion hoa phat sang chat dupe nha khoa hpc Anh Edward Townsend (1868-1957) phat hien da dupe dng dung de che tao cac loai den phdng dien Den hoi Natri (Sodium) ap suat thap Van Voorhir che tao t d nam 1923 cho anh sang don sac mau vang, chung co the chuyen hoa 80% dien nang quang nang, vi vay co hieu qua anh sang rat cao, dat tdi 200 Im/W, nhUng he so the hien mau rat thap, gan bang khdng Den Sodium ap suat cao co the chuyen hda 50 % dien nang quang nang, cho anh sang gan voi mau trang hon, hieu qua anh sang dat tdi 120 Im/W, chu yeu dung cho chieu sang cdng cdng Nam 1933 cac den dng huynh quang dau tien da dupe ban thi trudng va da trd nguon sang chu yeu, dupe sd dung rpng rai de chieu sang nha Cac den huynh quang the he mdi co hieu qua anh sang tdi 80 Im/W, chi so the hien mau 70-85 Cac den halogen kirn loai (Metal halide) cdng ty General Electric che tao t d nhPng nam 1960, cd hieu suat sang khong IPn hon den Sodium ap suat cao, nhung cd anh sang trang hon va dugc Png dung rpng rai chieu sang cdng cpng, chung cd the dupe che tao vdi cdng suat IPn co kW, hieu qua sang dat tdi 95 Im/W, thich hpp cho chieu sang cac cong trinh van hoa, the thao Co khoang tren 6000 loai den khac va dupe phan chia nhom chinh: • Den spi dot va spi dot halogen Day la nguon sang don gian, sd dung thuan tien, cd he so the hien mau rat cao CRI = 100 Tuy nhien hieu qua nang lupng thap, tuoi thp thap nen cd xu hudng bi loai bd • Den phdng dien chat dd cd den huynh quang, den thuy ngan cao ap, den Metal Halide, den Sodium ap suat cao va ap suat thap Day la cac den dupe sd dung rpng rai chieu sang ndi that va ngoai that hien • LED nguon sang ban dan LED ddi t d nhung nam 60 cua the ky trudc, dupe dng dung de hien thi thoi gian cua ddng hd bao thdc hay dung lupng pin cua may ghi hinh thong qua anh sang dd, xanh la cay, vang ma chua cd mau traing Nam 1993, Cdng ty Hda chat Nichia cua Nhat Ban da nghien cdu hoan chinh cdng nghe che tao loai den LED cho anh sang trang LED dpa tren cdng nghe ban dan Hien tai, LED cho anh sang trang cd tudi thp toi 50 nghin gid sd dung, gap 50 lan so vdi bong den 60 W thong thudng LED se thay the dan den spi dot va den huynh quang bdi nhUng Uu diem nhutiet kiem nang lupng tieu thu t d 70 den 80% so vdi loai den thong thudng; tudi tho cao; kich cd nhd; nhiet nang sinh qua trinh hoat ddng khong dang ke; hoat dpng tot dieu kien nhiet dp thap; sd dung ddng dien mpt chieu vdi hieu dien the nho; khdng gay d nhiem mdi trUdng vi khdng sinh tia cue tim, khdng cd thuy ngan Bieu hieu suat Lumen/Watt cua cac loai den Den day toe Halogen 20K | m Halogen lOK Halogen thuong mai Den huynh quang T5/T8 Den LED loai tot nhat 20 40 GO 80 100 120 Hinh So sanh hieu suat cac loai den So sanh hieu suat cac loai den dupe cho hinh Ta nhan thay bat dau t d nam 2000 cac den LED sieu sang co dac tinh quang va chi tieu nang lupng tuong duong vdi den huynh quang NGUYEN LY LAM VIEC CUA LED Phan chu yeu cua mpt chip LED la tinh the ban dan InGaN tao nen chuyen tiep p-n , dupe ddng goi voi chan ndi va thau kinh (hinh 2) Khi dat dien ap nhd len chuyen tiep se tao nen cac dien tich di ddng chay qua chuyen tiep va bien ddi nang lupng d u anh sang Nang lupng sptai hpp dien t d Id trdng giai phong se phat sinh cac photon Tren hinh cac dien t d dupe bieu dien bang vdng nhd mau xanh, cdn Id trdng bang mau Khi dat vao dien trUdng chung chuyen dpng va tai hpp vung chuyen tiep gpi la vung ngheo Sp chuyen mdc nang lupng cua cac hat giai phdng photon va phat anh sang Budc song bde xa, nghia la mau cua LED phu thupc vao vat lieu cua Idp chuyen tiep Quang thong LED phat chi nam dai hep Hinh Cau tao cua LED Automation Today / 12, 2010 De md rpng mau cua LED ngUPi ta sddung phot dupe kich thich bang LED, chung phat mau da trai Chat cho Cnat nh hieu qua tuong t u den dng huynh quang Hinh la den chieu sang ngd xdm cdng ty chieu ? n Hinh Den ong LED sang Da N l n g che tao 0„OO0fllO 0~«* o o 8„0 o ° o ° o W ° °S* • ; • o p W o V n n n n rr o n • pl I I H |4— Vung ngheo — I I 0 : Q H/nh Nguyen ly hoat dong cua LED LED SIEU SANG MAU TRANG De tao nen LED mau trang ta co the thpc hien theo cong nghe: • Sddung phot hap thu anh sang xanh va hoi phat anh sang trang Tren hinh 4a la LED sieu sang mau trang dupe tao bdi LED xanh co phu phot Hinh 4b la anh sang LED tao ra, co the dat nhiet dp mau 5000K va CRI = 90, cong suat moi chip co the len toi W, hieu qua nang lupng thong thuong 60 Im/W, co the dat toi 150 Im/W phong thi nghiem (a) ( b) 4) CHIEU S A N G T R A N G TRI B A N G LED Sd dung LED chieu sang trang tri cd Uu diem vupt trpi so vdi cac nguon sang truyen thong LED co kich thudc nhd, dp ben co cao, cd the tao nen hang trieu mau t d viec phdi hpp cac LED mau co ban R (Red), G (Green), B(Blue) Trong chieu sang le hdi 1000 nam Thang Long, cdng ty Chieu sang thi Ha Ndi (H APULICO) da sd dung nhieu logo hinh rdng, de quat, bieu tupng Ha Ndi tao nen anh sang mau lung linh vdi nhieu kich ban khac Hinh la mdt so mau chieu sang 1000 nam Thang Long 5) MOT SO LTNG DUNG CHINH CUA LED: Hinh Tao nen LED trdng (b) bdng each phu photpho (a) ten LED xanh • Sd dung chieu sang chieu sang cdng cpng, chieu sang cac toa nha va hp gia dinh • Sd dung lam bp phan hien thi cac thiet bi dien, • Bo tri LED (a), da trdi (b) va xanh la cay (c) gan nhau, chung hoa mau va tao nen mau trang (d) Hien LED mau dien td, den quang cao, trang tri, den giao thong va da cam co hieu suat sang 17-23 Im/W, cao hon den spi • Cac LED phat tia hong ngoai dupe dung dot mot chut nhUng van kem xa cac den phong dien cac thiet bi dieu khien t d xa cho dien t d dan dung Sd dung lam den xe, den dudng, den ham mo, den chieu hau cho man hinh cua dien thoai cam tay, den chieu hau cho man hinh tinh the long (LCD), in an ky thuat so a) b) c) d) Hinh Tao nen LED mau trdng tif LED do, xanh, lo De tang cong suat cua nguon sang nguoi ta sd dung ma tran LED gdm cac chip LED dupe mac ndi tiep va song song Hinh la den dng gdm cac chip LED mac ndi tiep cd 14 Tu dong hda / 12, 2010 • L/ng dung rdng rai tren cac ITnh vpc: bang quang cao ngoai trdi, bang quang bao, ddng hd cd Idn dat tai cac bien quang cao tarn Ion tren duong cao tdc, he thong den giao thong, bien chi dan, va cac san pham khac nhu bang chay chu dien td, bang he thong gid, Bang ty gia, bang chdng khoan, he thong xep hang tii dpng • LED co the duoc sd dung nhieu ITnh vpc nhu" den doc, chieu sang be boi, nhat la cho chieu sang Tong chieu dai la 40m, moi Rong co kich thudc 16m, logo Ha Npi duong kinh la 5.5m Toan bp khung gian se dupe gia co bdi cot thep bpc inox, each mat dat 5m Hinh Chieu sang le hpi WOO nam Thang Long bang LED quang cao ngoai trdi tai nhung noi kho thay lap, co tuoi thp cao hon nhieu lan so vdi bong den ne-dng, dong thdi co nhieu mau sac phong phu nhU: do, xanh la, xanh da trdi, mau ho phach Tren thpc te Cong ty Electric General va Might Technologies of Evanston III da tao cac bien quang cao bang den LED rpc ro nhu den ne-ong • Mpt dac diem khac cua LED la it tieu hao nang lupng va khong nong Bong den truyen thong, den neon, den halogen deu can tP 110-220 V moi chay dupe, den LED trang chi can tP 3-24 V de phat sang Phan chia thi trUdng LED nam 2008 dupe cho tren hinh Hinh Phan chia thi trUdng LED dien t d cd be day phat trien va co the manh tren thi trudng Dan dau la tap doan chieu sang so Philips vPi 164 sang che, t h d hai la Cree Inc vdi 33 sang che Mpt so tap doan dien t d khac cung da ghi ten minh tren ban sang che la Gelcore LLC (28), Osram (27), Siemens (23), Samsung (20), LG (17), Univ (15) d Viet Nam nhieu cdng ty che tao thiet bi chieu sang nhU Rang Ddng, Dien Quang, TrUdng DHBK Ha Ndi va nhieu cdng ty khac da trien khai nghien cdu va che tao nhieu chung loai LED Khd khan chinh cua LED la tan nhiet tang cdng suat LED.G Phan chia thi truong LED, 2008 6) TLTONG LAI CUA LED LED dang phat trien rat nhanh va dang canh tranh vPi cac den truyen thong nhieu Png dung Trong tuong lai gan cac LED se hoan toan thang the va la nguon sang cua tuong lai TP nam 1974 den (thang 10/2009) co 2.272 sang che ve LED Nhin ban sang che cua LED qua cac nam, co the nhan thay dudng phat trien cua cong nghe LED chia lam chang ro ret TP nhung nam 2000 trd ve truoc, sang che LED chi ddng d sd hang chuc thi t d nam 2000 den nay, so lupng sang che ve LED tang vqt, dat den so hang tram Cac cdng ty sd huu cac sang che LED chinh la cac cdng ty Automation Today / 12, 2010 ... nghien cdu va che tao nhieu chung loai LED Khd khan chinh cua LED la tan nhiet tang cdng suat LED.G Phan chia thi truong LED, 2008 6) TLTONG LAI CUA LED LED dang phat trien rat nhanh va dang canh... Tao nen LED mau trdng tif LED do, xanh, lo De tang cong suat cua nguon sang nguoi ta sd dung ma tran LED gdm cac chip LED dupe mac ndi tiep va song song Hinh la den dng gdm cac chip LED mac ndi... Png dung Trong tuong lai gan cac LED se hoan toan thang the va la nguon sang cua tuong lai TP nam 1974 den (thang 10/2009) co 2.272 sang che ve LED Nhin ban sang che cua LED qua cac nam, co the