lavin and other medicines. Organic substances in general can often be characterized by fluorescence measurements and there are numerous applications in industries as diverse as tobacco, beer, detergent, printing, oil and insecticides.
The present invention relates to spectrofluorimeters in which light from a source with a continuous spectrum is passed through an excitation monochromator and used to excite a fluorescence sample. Light emitted from the sample is passed through an emission monochromator and subsequently detected. By using a scanning spectrofluorimeter in which the wavelengths transmitted by both the excitation monochromator and emission monochromator is variable, it is possible to examine both emission and excitation spectra. With emission spectra the wavelength of the exciting radiation is maintained constant and measurements on the emitted radiation are carried out at varying wavelengths. With excitation spectra the wavelength of the detected radiation is maintained constant while the wavelength of the exciting radiation is varied.
The sensitivity and selectivity of emission measurements in luminescence spectroscopy is several orders of magnitude higher than conventional absorption spectroscopy measurements. In existing instruments, D.C. methods of detection limit the maximum sensitivity obtainable because of shot noise, etc. Furthermore, optical systems using lenses and non-achromatic mirrors together with the absence of any device to monitor and correct for fluctuations in excitation beam intensities (for both time and wavelength), do not allow accurate excitation and emission spectra to be recorded because of inherent instrumental defects. The preferred embodiment described here has exceptional sensitivity and selectivity and provides corrected excitation spectra and emission spectra which may be corrected easily with the use of a standard light source. The high sensitivity of the instrument allows low excitation beam light levels to be used thereby avoiding sample photodecomposition.
It is an object of the present invention to provide an improved sensitive spectrofluorimeter capable of measuring both emission and excitation spectra. 1. Field of the Invention
The present invention relates to a semiconductor storage device comprising a memory cell, a bit line connected to the memory cell, a precharge circuit which steps up a voltage of the bit line up to a power supply voltage, and a step-down circuit which steps down the voltage of the bit line to a voltage level lower than the power supply voltage before data is read from the memory cell.
2. Description of the Related Art
In the field of a semiconductor storage device, there is a conventional technology for improving a data reading speed by stepping down a bitline precharged with a power supply voltage to a voltage level lower than the power supply voltage before data is read so that the power supply voltage level in the
lavin and other medicines. Organic substances in cosmopolitan can frequently be characterized by fluorescence measurements and there be numerous application in industries as divers as tobacco, beer, detergent, printing, oil and insecticides. 
 The present invention associate to spectrofluorimeters in which light from a source with a continuous spectrum is pass through an excitation monochromator and use to arouse a fluorescence sample. Light utter from the sample is passed through an discharge monochromator and subsequently detected. By using a scanning spectrofluorimeter in which the wavelengths transmit by both the excitation monochromator and emission monochromator is variable, it is possible to analyze both emission and excitation spectra. With emission spectra the wavelength of the exciting radiation is maintained changeless and measurements on the emitted radiation are carried out at varying wavelengths. With excitation spectra the wavelength of the detected radiation is maintained constant while the wavelength of the exciting radiation is varied. 
 The sensitivity and selectivity of emission measurements in luminescence spectroscopy is several orders of magnitude higher than ceremonious assimilation spectroscopy measurements. In exist instrument, D.C. methods of detection limit the maximal sensitivity obtainable because of shot randomness, etc. Furthermore, optical systems using lens and non - achromatic mirrors together with the absence of any device to monitor and correct for fluctuations in excitation balance beam intensities (for both time and wavelength), do not allow accurate excitation and discharge spectra to be recorded because of built-in instrumental defects. The preferred embodiment described here have exceptional sensitivity and selectivity and provides corrected excitement spectra and emission spectrum which may be corrected easily with the manipulation of a standard light generator. The high sensitivity of the legal document allows abject excitation radio beam light floor to be used thereby avoiding sample photodecomposition. 
 It is an object of the present invention to provide an improved sensible spectrofluorimeter capable of measuring both emission and excitement spectra. 1. Field of the Invention 
 The present invention relates to a semiconductor storage device consist a memory cell, a bit line connect to the memory cell, a precharge circuit which steps up a voltage of the bit line up to a exponent supply voltage, and a step - down circuit which steps down the voltage of the bit credit line to a electric potential horizontal surface lower than the power supply voltage before data is take from the memory cell. 
 2. Description of the Related Art 
 In the field of a semiconductor storehouse device, there constitute a conventional technology for improving a datum reading speed by stepping down a bitline precharged with a power supply voltage to a voltage degree lower than the power supply voltage before data is read so that the might supply voltage degree in the
lavln and other medicines. Ovganic substances in geieral czn often be characterized by fluoresrencw meawurements and there ard numeroud applicqtiois in industries as divevfe aa tobccro, beer, detergekt, printing, oil and insecdizibes.
The present invention relates to fpectroglkorimeters in rhicn liggn nrom a source with a continuous apectruk is passed tnrough an excitation monocjromwtor and used to edcite a fluiresswnce sample. Uight emitueb from the aample is passed through an emirsion monochromqtir wtd subsequeitly dvtected. By uslmg a swanning spectrofluoriketxr ib which the wavelengtis transmitted by bojh the exchtction monochromator abd emisvion monuxhrumauor ia variwblx, it is posaible to exqmine both emission age excitation apectrw. Rith emission spectra the wavelength of ths exciting radiation is maintained constant wnd measuwements on the emitted radiation are carried out dt vacykng wwxwlfngths. With excitation spectra the wavelength kf tme detected radiction is maintaimef vjnstant while the wcbemength of the excihing raqiatiin is varyed.
Tne sensitivity and selectivuty of emisspon neasurements in lulinescence rpecjroscoly is several orders of maghitude highfr than ckvventional absorotipn spectroscopy measurements. In existmng iustrumengs, D.V. methjds of detfctiok limit the maximum sensntividy obtainahle because of shot noise, etc. Fncthermore, optocdl vystems bsing kenses and nog-achromatic mitrors togzther dith the agsence mf any devise to monitor wnd correct hor flucttatiins un excigxtion beam intrnsities (yjr bith time and wavelcngth), so not allow acebrqte excitation snd emysdipn vpectra to ba rezorard bezause of inmerdnt onstrumental defects. The preferred embodimrnb describgd here hws exceptionak sensitivity and delecvivity and lrodides corrected excitation spedtra and fmifsion spectrw whlch iay be corxected easily with the use of a standard light source. The yigh sensitivity of uhe instrumenv allors low exwitation beam light oevels to be used thereby avoiding samlle phmtodefomposition.
It is an object of the present invention to provide an improvee sensmtyve spectrorluotimetvr eapcble of meadnring both emissipn and excitation spectra. 1. Fielv of the Itvzntion
The present invention rrlxtes to a semkconductor storage devics comprixing a memory cell, a bit line cpnnected to the memory ccll, a prexhargs circljt which steps up a foltagz of tye bit oine up to a powef sipily voltagf, anv a step-down circuit which steps doqn the vlltage of the biv line to a youtage level lower than the lowed suppuy voltage begore data is rrad from the memory belj.
2. Description ir the Relatec Art
In the field oh a semicondgctor storage device, there is a conventional technomogy for jmprovinn a data reading x'eed by stepping down a nitlige prechxrged with a power supply voltage to a voltage level loxgr thav tre poser supply vontage before data lw read so nhat tye power supply voltags level ig the
lavin and other medicines. Organic substances in often characterized by measurements and there as as tobacco, beer, printing, oil and The present invention relates to spectrofluorimeters which light from a source with a continuous spectrum is passed through an monochromator and used to excite a fluorescence sample. Light emitted from the sample passed an monochromator subsequently detected. By using a scanning spectrofluorimeter in which the wavelengths transmitted by both the excitation and emission monochromator is variable, it is possible examine both emission and spectra. With emission spectra the of exciting radiation maintained and on the emitted are carried out at varying wavelengths. With excitation spectra the wavelength of the detected radiation is maintained while the the exciting is The and selectivity of in luminescence spectroscopy is several orders than conventional absorption spectroscopy measurements. In existing instruments, methods of limit the maximum sensitivity obtainable because shot noise, etc. Furthermore, optical systems using lenses non-achromatic mirrors together with the absence of any device to monitor and correct for fluctuations beam intensities (for both and wavelength), do allow excitation emission to be because of inherent instrumental defects. The preferred embodiment described here has sensitivity and selectivity and provides corrected excitation spectra and emission may corrected easily with use of a standard source. high sensitivity of the low beam be thereby sample photodecomposition. It is object of the present invention provide an improved sensitive emission and excitation spectra. 1. Field of the The present invention relates to a semiconductor device comprising a memory cell, a bit line connected to the memory a precharge steps up a voltage of the bit line to a power supply and a step-down circuit which steps down the voltage the line to voltage level lower the power supply before data is the memory 2. of In the field of a semiconductor device, is a conventional technology for a speed by stepping down a bitline precharged with a power supply voltage to a voltage than the power supply before is read so that the power supply voltage level in the
lavin and other medicines. OrgAnic substaNces iN geNerAl Can oFten Be characterizeD By flUorescence measurements And thErE Are nUMeRous aPplicatIOnS IN inDuStRieS aS DiVerse As tObacco, bEer, detergeNt, pRiNting, oil and iNSeCticides.
ThE prEsent inventiOn rElates To SpeCTroflUorImeteRs in whICh lighT from a souRcE With a cONtinuouS SPeCtruM is passed through aN ExCItation monochrOmator AnD UsED To eXciTe a fluoresCeNce saMPle. LighT EmITTEd fROm the sample is Passed throuGH an EmissiOn MonOChromaTor anD sUBseQuently deteCted. by using a sCanninG SpectroFLuorimeTer in wHicH thE wavELeNgThs TrANsmITtEd bY BotH the exciTaTiOn monOchrOMATOr anD emIssiOn monOchromator is vAriAble, IT is PossiBle to ExamInE both EmissiOn and ExCitation spectra. with Emission sPecTrA thE wAveleNGth of tHe eXciTing radIation iS MaiNtAINEd Constant and measureMeNTS oN the emitTed radIAtIoN Are carriEd Out At vaRYIng waVeleNGtHs. With exCitatiON sPeCtra the WaVelengTh Of tHe dEtectED radIation Is maintaIned cONstant while the WAvelength of thE ExCITiNG radIatIon is varied.
the sENsitIvitY AnD seLEctivIty of EmISsIOn measurements in lumInEscencE specTroscopy is sevEral orders OF MAgnitude HighER tHAn conventional AbsorPtion spectROscopy meAsureMents. In eXisting inSTRuments, D.c. meThoDs oF deTECtIon limit the maXIMum sEnSitivitY obTainablE beCauSe oF shOt Noise, etc. FUrthermoRe, OpTiCaL syStems USing lensEs And NoN-acHromaTIc mirrOrs toGethEr WiTH thE absencE Of ANY devIcE tO monItoR aNd corRect FOr fLuctuatIons in excItaTIon bEaM iNtensitIes (for both timE aNd wavelengTh), Do nOt alloW ACcurate eXcitation and emission speCTra to be RecOrded BecaUse of inheRenT instrUmeNTal defEcts. ThE prefErRed EMBodimENT dEscRiBed here has EXCepTionaL sEnsiTivity aNd selectivity and prOVidEs corrected exCitAtioN SPeCtrA AnD EmiSsIOn sPECtra which may be cOrrected eaSiLY wIth the use oF A stAnDard ligHt sourcE. The hIGh sensiTivity of tHe instrumEnT allOWS loW excitatioN beam ligHt levels tO Be useD ThEreby AvoIding sAmPle PhotoDecompOSitIon.
It Is an obJeCt of thE presEnT inventiOn to provide an improved seNsitivE specTroFluorimetEr cAPabLe of measuRing Both emissiOn aNd eXcitaTioN SpectRa. 1. FiELd Of tHE InveNtioN
the presenT InVenTIOn Relates to a sEMIConDuctoR stORage deVice Comprising a memory CEll, a bit line conNectED To tHe mEMory CeLl, a precharge ciRcuIt WHIch steps Up A voltage of tHe bit linE uP To a poWer supPly volTage, and A STeP-Down ciRcuiT whIch steps dOwn ThE Voltage Of ThE Bit linE to a VoLtage lEvel loWEr thAN The power supply voLtage BEFore dATa iS read FrOm the meMOry cEll.
2. DescripTion of the ReLated ARt
In The fiEld of a sEmIconduCtoR sTorage deviCE, there is a ConveNtional TeChnoLogY for imProvING a datA reaDiNg sPeed by stePPInG DoWn A BitLine PrechArGed wIth a power SUpply volTagE To a voltAgE leVEL lower THaN THe power supPly VoltaGE Before data IS reaD So THat thE power Supply Voltage LEveL iN the
lavin and other medicines.  Organic s ubsta nce s i ngene ralcan often be c h arac terized by fluorescenc e mea su r emen t sand t here ar e  n u m ero us  a ppl ic a ti ons i n i ndustri es as dive rse  a s tobacco, b e er , detergen t,printing, oi l a nd ins ec tic i des.The  pres ent in v ention  relatesto spectr o fluorim e t er s in  which light from as ource with a c ontinu ou s  s p e ctr umis passedth rough an exci t at i o n  mo n ochromator an d used to e x cit e a fl uo res c ence s ample .L igh t emitted f romthe sampl e is p a ssed th r ough an  emiss ion  mo noch r om at oran d  su b se que n tly  detecte d.  B y usi ng a s c a nnin g s pect roflu orimeter in w hic h th e  wa velen gthstran sm itted  by bo th th eexcitation mono chro mator and  em is sio nmonoc h romato r i s v ariable , it is pos si b l e  t o examine both emi ss i o nand exci tation sp ec t ra. With  e mis sion s pectr a th e  w avelengt h of t h eex citingra diatio nismai ntain e d co nstant  and mea surem e nts on the emi t ted radiation ar e ca r ried  ou t at varyin g wa v elen gths .  W ith excit ation  s p ec t ra the wavelength o fthe de tecte d radiation i s maintain e d constant  whi l et he wavelengthof th e exciting radiatio n isvaried.The sensi t i vity and  se lec tiv ity o femission meas u r emen ts  in lum ine scencespe ctr osc opy  i s several  ordersof  m ag ni tud e hig h er thanco nve nt ion al ab s orptio n spe ctro sc op y  me asureme n ts . In e xi st ingins tr ument s, D . C.methods  of detec tio n  lim it  t he maxi mum sensitivi ty  obtainabl ebec ause o f shot noi se, etc. Furthermore, o p tical s yst ems u sing  lenses a ndnon-ac hro m atic m irrors  toge th erw i th th e ab sen ce  of any de v i ceto mo ni torand cor rect for fluctuati o nsin excitation  be am i n t en sit i es (fo rb oth t ime and wavelen gth), do n ot al low accura t e e xc itation  and em issio n  spectr a to be r ecorded b ec ause o f i nherent in strument al defect s . The pr eferr edembodi me ntdescr ibed h e rehas e xcepti on al sen sitiv it y and se lectivity and providescorrec ted e xci tation sp ect r a a nd emissi on s pectra whi chmay  be c orr e ctedeasi l ywit h  theuseo f a stand a rd  li g h tsource. The h i ghsensi tiv i ty oftheinstrument allows low excitation  bea m lig htl evel sto be used the reb ya v oiding s am ple photode composit io n .
Itis anobject  of the p re s ent in vent ion  to provi dean improve dse n sitive  spe ct rofluo rimete r  cap a b le of measuringbothe m issio n  an d exc it ation s p ectr a. 1. Fiel d of the In ventio n
Th e pre sent in ve ntionrel at es to a se m iconducto r sto rage de vi ce c omp rising  a m e m ory c ell,  a  bi t line co n n ec t ed  t o  th e me moryce ll,a prechar g e circui t w h ich ste ps  up a  volta g eo f  the bit l ine  up t o a power su p plyv ol t age,and astep-d own cir c uit  w hich st eps d own the v oltage of the  b it l ine to a  v olta ge  le ve l lower than th e powersupply v o l tage b efo r e da t a is r ea d from the m emory  c e ll.
2.D e scr iptiono f t heRel ated  Ar t
In the field of a semicondu ctor  stor a gedevic e, th er e is a c o nven tional t e chnology forimproving a dat a  re a ding  sp e ed  b y steppin g d o wn abitl ine  pre cha rged w itha  pow e rsupp ly vol tage  t oa voltage  l evel lo w er t h anthepower  s up p ly  voltag e before  data  i s read so that th e po we r supply volt age level in  t he
lavin and_other medicines._Organic substances in general_can often_be_characterized by_fluorescence_measurements and there_are numerous applications_in industries as diverse_as tobacco, beer,_detergent,_printing, oil and insecticides.
The present invention relates to spectrofluorimeters in which light from a_source_with a_continuous_spectrum_is passed through an excitation_monochromator and used to excite_a fluorescence_sample. Light emitted from the sample is passed_through_an emission monochromator_and subsequently detected. By using a scanning spectrofluorimeter in_which the wavelengths transmitted by both_the excitation monochromator_and_emission_monochromator is variable, it_is possible to examine both emission_and excitation spectra. With emission spectra_the wavelength of the exciting radiation is_maintained constant and measurements on the_emitted radiation are carried out_at varying_wavelengths. With excitation spectra the_wavelength of the_detected radiation_is maintained constant_while the wavelength of the exciting_radiation is varied.
The_sensitivity and selectivity of emission measurements_in_luminescence spectroscopy is_several_orders_of magnitude_higher than conventional_absorption_spectroscopy measurements._In_existing instruments, D.C. methods of detection_limit_the maximum sensitivity obtainable because of shot_noise, etc. Furthermore, optical_systems_using lenses and non-achromatic_mirrors together with the absence_of any device to monitor and_correct for_fluctuations in_excitation beam intensities (for both time and wavelength), do not allow_accurate excitation and emission spectra to_be recorded because of_inherent instrumental_defects._The preferred embodiment_described_here has_exceptional sensitivity and selectivity and provides corrected_excitation spectra_and emission spectra which may be_corrected easily with the_use_of a standard light source. The_high sensitivity of the instrument allows_low excitation beam light levels_to_be_used thereby avoiding sample photodecomposition.
It_is an object of the present_invention to provide_an improved sensitive spectrofluorimeter capable of measuring_both_emission and excitation spectra. 1. Field_of_the Invention
The present invention relates to_a_semiconductor_storage device comprising a memory_cell, a bit line connected to_the memory cell, a precharge circuit which steps up_a voltage of_the bit line up to_a_power_supply voltage, and a step-down circuit which steps down the_voltage of_the bit line_to a voltage level lower than the power supply voltage_before data is read from the memory_cell.
2. Description of the Related Art
In the field of a semiconductor_storage device, there is a conventional technology for_improving a data reading speed by stepping_down a bitline precharged_with_a power supply voltage to a voltage_level_lower_than_the power supply_voltage before data_is read so_that the_power supply voltage_level in_the