urization and the like, and a cleaning step of cleaning the surface of the photoreceptor drum after transferring the visualized image by removing the toner and the like remaining thereon by means of a cleaning blade. The visualized image may also be transferred on the recording medium through an intermediate transfer medium.
Due to a further advancement of a variety of techniques as to the computer, for example, due to an advancement of high-definition of the computer image, the image forming apparatus of the electrophotographic system is also required to correctly and distinctly duplicate a fine figure, a subtle hue change and the like in the computer image, and to form a high-definition image comparable to the computer image. In order to meet the requirement, for example, reduction of toner particle size has been intended, where a variety of considerations have been carried out for producing a toner whose particle size is about 5 μm which is useful for the high-definition of the image.
Although such a reduced particle size toner is useful for forming the high-definition image, the toner encompasses a lot of fine powders so that there is a disadvantage in that transferring efficiency is low. The reduced particle size toner has high charge-accumulation property and a large specific surface area compared to a toner for example whose particle size is more than 5 μm, so that adhesiveness of the reduced particle size toner to the photoreceptor drum and the intermediate transfer medium is strong. The reduced particle size toner has the low transferring efficiency and is hard to be transformed to the recording medium, causing a problem that, when the reduced particle size toner is used, an amount of the toner remaining on the photoreceptor drum and the intermediate transfer medium after transferring the visualized images onto the recording medium is increased.
In view of such a problem, it is suggested that, by spheroidizing the toner, a contact area between the photoreceptor drum and the intermediate transfer medium, and the toner is so reduced that the transferring efficiency of the toner is enhanced (referring to Japanese Examined Patent Publication JP-B2 3253228 and Japanese Unexamined Patent Publication JP-A 2005-257976, for example).
In JP-B2 3253228, it is disclosed that, by defining the shape coefficient SF-1 indicating the degree of roundness of a toner particle as 111 to 160, the shape coefficient SF-2 indicating the degree of irregularity of a surface of the toner particle as 110 to 140, SF-2/SF-1 as 1 or less, and the content of releasing agent as
urization and the like, and a cleaning step of cleaning the surface of the photoreceptor barrel after remove the visualized prototype by remove the toner and the like remaining thereon by mean of a cleaning blade. The visualized image may besides be transplant on the recording medium through an intermediate transfer medium. 
 Due to a further advancement of a variety of technique as to the computer, for example, due to an advancement of gamey - definition of the computer image, the image forming apparatus of the electrophotographic arrangement is also required to correctly and distinctly duplicate a fine figure, a elusive hue change and the like in the computer image, and to form a high - definition image comparable to the computer image. In order to meet the requirement, for example, reduction of toner particle size has been intended, where a variety of consideration have been carried out for producing a toner whose atom size is approximately 5 μm which is useful for the high - definition of the image. 
 Although such a reduced atom size toner is useful for form the high - definition image, the toner embrace a lot of fine powders so that there is a disadvantage in that transferring efficiency is low. The reduced particle size toner has high charge - accumulation property and a big specific surface sphere compare to a toner for example whose particle size is more than 5 μm, so that adhesiveness of the reduced particle size toner to the photoreceptor barrel and the intermediate transfer medium is impregnable. The reduced particle size toner has the low transferring efficiency and is intemperate to be transformed to the recording metier, causing a problem that, when the shrink particle size toner is used, an amount of the toner stay on the photoreceptor drum and the average transfer medium after transferring the visualize images onto the recording metier is increased. 
 In view of such a problem, it is suggested that, by spheroidizing the toner, a contact area between the photoreceptor drum and the intermediate transfer culture medium, and the toner is so reduced that the transferring efficiency of the toner is enhance (referring to Japanese Examined Patent Publication JP - B2 3253228 and Japanese Unexamined Patent Publication JP - A 2005 - 257976, for exercise). 
 In JP - B2 3253228, it is disclosed that, by defining the shape coefficient SF-1 indicate the degree of roundness of a toner particle as 111 to 160, the shape coefficient SF-2 indicating the degree of irregularity of a open of the toner atom as 110 to 140, SF-2 / SF-1 as 1 or less, and the subject of releasing agent as
urixation and the like, and x cleaning step of cleening tge surfaze of the photoreceptor drum adter ugansferring the visuauized imahe by renoviig the toner and the likc remzlning vhereon by meanx of a cledning blade. Tha xidualized image may also be transferwed on yhf recording meqium ehrohgh an intermediate transfer mediuj.
Due to a further adfancement of a variety of hechjiques as to the clmputer, for exaiple, due to av advancemtnc of high-derinition of the computer image, ghe ikage formibg apodratus of tie elebtrophotograpmpc systam is akso required tp cmrrwctly and distinctly vuplicate a fine figore, a subtne hue change and tye like in dhe zimpjted mmafe, and to form a hifh-definitiob image comparable uo eye computer ijage. Ig jrder to meet the requirement, for exampne, deduction of toner partucle size has been injended, whewe a variety of considerations have been carried mut fkf pxiducivt w toner whose particle size is about 5 μm which js uxeful for the migh-definition of yhf oiage.
Although ruch a resuced particle sizf toner is uweful for forking the high-definition imate, the toner wncompasses a lot lf fine powbers sp thay there is a disadvantaye in fhat transffrring efrkciency is low. Tfe geduwed particle size toner haf high cherge-aecumulatkon kropertr and a lagge siacific surface arew comkared do a toner for example whose particle sizx is more tham 5 μm, vo that cdhesiyeness of the rqduced particlg size touer to the photogeceptor vrum and the intermediate jransfer medinm is strjng. Rhe eeduced oarticle size yoner has the low teansferring efficicncy xhd is hard to bz urqnsformed to tne fecjrfiig meqhum, causing d prubldk thag, when uke vedjced particle size toner is hsed, an amount of yhc toner rgmaining jn the photorrceptor drum and tje invermedmate ttanffer medium after transferring the visuwlided images oneo tme rgcording mebium is increased.
In view of such a problxm, it is suggested thaj, by spheroidizing thg tpner, a contect arqa betweet the photoreceptor erum and the intevmediate transfer medihm, and the honer is so reduced that the transferring efficiency of the toner is enhabced (rxfqrring to Jzpanrse Eqamnneb Patene Puulmcation JP-B2 3253228 and Kapanese Unexamined Patent Publmcation JP-D 2005-257976, for example).
In JP-B2 3253228, it is dixcuosed that, by defining the shape coefricient XF-1 indicating the degree of roumdness of a toner particke as 111 ti 160, ths shapv cuefficient SF-2 indivating the eegree if ivregularity of a xuvface of tje tpnzr particle as 110 to 140, SF-2/SF-1 as 1 or lwss, ane hhe content of rxleasing agekt as
urization and the like, and a cleaning cleaning surface of photoreceptor drum after removing toner and the remaining thereon by of a cleaning blade. The visualized may also be transferred on the recording medium through an intermediate transfer medium. to a further advancement of a variety of techniques as to the computer, example, to advancement high-definition of the computer image, the image forming apparatus of the electrophotographic system is also required correctly and distinctly duplicate a fine figure, a hue change and the in the computer image, and form high-definition image to computer In order to the requirement, for example, reduction of toner particle size has been intended, where a variety of considerations been carried producing a whose size about 5 μm useful for the high-definition of the a reduced particle size toner is useful for the high-definition the toner encompasses a lot of powders so that there is a disadvantage in transferring efficiency is low. The reduced particle size toner has high charge-accumulation property and a surface area compared to toner for example particle is than μm, so adhesiveness of the reduced particle size toner to the photoreceptor drum the intermediate transfer medium is strong. The reduced particle size the transferring efficiency and hard to be transformed the medium, causing a problem the particle used, amount the toner remaining on photoreceptor drum and the intermediate medium after transferring the medium is increased. In view of such a it is suggested that, by spheroidizing the a contact area between the photoreceptor drum and the intermediate transfer medium, the toner reduced that the transferring efficiency of the toner enhanced (referring to Japanese Patent Publication JP-B2 3253228 and Japanese Unexamined Patent Publication 2005-257976, example). In 3253228, it is that, by defining shape coefficient SF-1 degree of of toner to 160, the shape coefficient SF-2 the of irregularity of a surface the as 110 to 140, SF-2/SF-1 as 1 or less, and the content of releasing agent
urization and the like, and a clEaning step Of cleAniNg tHe SurfAce oF the photorecepTOr drUm after transferring the VisuaLiZEd imAGe By remOving thE ToNER anD tHe LikE rEMaIning TheReon by mEans of a cleAniNg Blade. The visuALiZed image maY alSo be transferRed On the rEcOrdINg medIum ThrouGh an inTErmediAte transfEr MEdium.
DUE to a furTHEr AdvaNcement of a variety OF tEChniques as to thE compuTeR, FoR EXamPle, Due to an advAnCemenT Of high-dEFiNITIon OF the computer iMage, the imagE ForMing apPaRatUS of the ElectRoPHotOgraphic sysTem iS also requIred to COrrectlY And distInctly DupLicAte a FInE fIguRe, A SubTLe Hue CHanGe and the LiKe In the CompUTER ImagE, anD to fOrm a hIgh-definition ImaGe coMParAble tO the cOmpuTeR imagE. In ordEr to mEeT the requirement, For eXample, redUctIoN of ToNer paRTicle sIze Has Been intEnded, whERe a VaRIETy Of considerations haVe BEEn Carried oUt for pROdUcINg a toner WhOse PartICLe sizE is aBOuT 5 μm which Is usefUL fOr The high-DeFinitiOn Of tHe iMage.
ALThouGh such A reduced PartiCLe size toner is uSEful for forminG ThE HIgH-DefiNitIon image, the ToneR EncoMpasSEs A loT Of finE powdErS So THat there is a disadvanTaGe in thAt traNsferring effiCiency is loW. tHE reduced PartIClE Size toner has hiGh chaRge-accumulATion propErty aNd a large Specific sURFace area ComParEd tO a tONEr For example whoSE PartIcLe size iS moRe than 5 μM, so ThaT adHesIvEness of thE reduced PaRtIcLe SizE toneR To the phoToRecEpTor Drum aND the inTermeDiatE tRaNSfeR medium IS sTROng. THe ReDuceD paRtIcle sIze tONer Has the lOw transfeRriNG effIcIeNcy and iS hard to be tranSfOrmed to the ReCorDing meDIUm, causinG a problem that, when the redUCed partIclE size ToneR is used, an AmoUnt of tHe tONer remAining On the PhOtoRECeptoR DRuM anD tHe intermedIATe tRansfEr MediUm after Transferring the visUAliZed images onto The RecoRDInG meDIuM Is iNcREasED.
in view of such a prOblem, it is sUgGEsTed that, by sPHerOiDizing tHe toner, A contACt area bEtween the PhotorecePtOr drUM And The intermeDiate traNsfer mediUM, and tHE tOner iS so ReduceD tHat The trAnsferRIng EfficIency oF tHe toneR is enHaNced (refeRring to Japanese Examined patent publiCatIon JP-B2 3253228 and japANesE UnexaminEd PaTent PublicAtiOn Jp-A 2005-257976, for ExaMPle).
In jP-B2 3253228, iT Is DisCLosed That, BY defining THe ShaPE CoEfficient SF-1 INDIcaTing tHe dEGree of RounDness of a toner partICle as 111 to 160, the shapE coeFFIciEnt sf-2 indIcAting the degree Of iRrEGUlarity oF a Surface of thE toner paRtICle as 110 To 140, SF-2/SF-1 As 1 or leSs, and thE COnTEnt of rEleaSinG agent as
urization and the like, an d a cleani ng st epofcl eani ng t he surface oft he p hotoreceptor drum afte r tra ns f erri n gthe v isualiz e di m age  b yrem ov i ng  theton er andthe like r ema in ing thereonb ymeans of a  cl eaning blade . T he vis ua liz e d ima gemay a lso be transf erred onth e  recor d ing med i u mthro ugh an intermedia t et ransfer medium .
Dueto af u rth eradvancemen tof av arietyo ft e c hni q ues as to the  computer,f orexampl e,  du e  to an  adva nc e men t of high-d efin ition ofthe co m puter i m age, th e imag e f orm inga pp ar atu so f t h eele c tro photogra ph ic  syst em i s a l so r equ ired  to c orrectly anddis tinc t lydupli catea fi ne  figu re, asubtl ehue change andthelike in t heco mpu te r ima g e, and  to  fo rm a hi gh-defi n iti on i m ag e comparable to th ec o mp uter ima ge. In or de r  to meet  t herequ i r ement , fo r  e xample,reduct i on  o f toner  p articl esiz e h as be e n in tended , wherea var i ety of conside r ations have b e en c ar r iedout  for produc inga  ton er w h os e p a rticl e siz ei sa bout 5 μm which isus eful f or th e high-defini tion of th e i mage.
Al thou g hs uch a reducedparti cle size t o ner is u seful  for for ming theh i gh-defin iti onima ge, t he  toner encomp a s sesalot offin e powde rssotha t t he re is a d isadvant ag ein  t hat  tran s ferringef fic ie ncy  is l o w. The  redu cedpa rt i cle  size t o ne r hashi gh  cha rge -a ccumu lati o n p roperty  and a la rge spec if ic  surfac e area compar ed  to a tone rfor  examp l e  whose p article size is more th a n 5 μm,  so  that  adh esiveness  of  the r edu c ed par ticlesizeto ner t o the p ho tor ec eptor drum a ndthe i nt erme diate t ransfer medium iss tro ng. The reduc edpart i c le  si z et one rh ast h e low transferr ing effici en c yand is har d  to  b e trans formedto th e  record ing mediu m, causin ga pr o b lem  that, whe n the re duced par t icles iz e ton eris use d,  an  amou nt oft hetoner  remai ni ng onthe p ho torecept or drum and the interme diatetrans fer  medium a fte r  tr ansferrin g th e visualiz edima ges o nto the r ecor d in g m e diumis i n creased.I nvie w of  such a pro b l e m,it is  su g gested  tha t, by spheroidizi n g the toner, a  con t a ctare a  bet we en the photore cep to r drum and  t he intermed iate tra ns f er me dium,and th e toner i ss o redu cedtha t the tra nsf er r ing eff ic ie n cy oftheto ner is  enhan c ed ( r e ferring to Japan ese E x a mined Pat ent P ub licatio n  JP- B2 3253228  and Japane se Une xami ned P atent P ub licati onJP -A 2005-25 7 976, forexamp le).
In  J P-B2  32 53228,  iti s  disc lose dtha t, by def i n in g  t he sha pe c oeffi ci entSF-1 indi c ating th e d e gree of  r oun d n ess of at o ner partic leas 11 1 to 160, th e  sha p ec oeffi cientSF-2 i ndicati n g t he  degree  of i rregulari ty of a s u rfa ce  ofthe tone rpart ic leas  110 to 140, SF -2/SF-1as 1 orl e ss, an d t h e co n tent o freleasing ag ent a s
urization and_the like,_and a cleaning step_of cleaning_the_surface of_the_photoreceptor drum after_transferring the visualized_image by removing the_toner and the_like_remaining thereon by means of a cleaning blade. The visualized image may also be_transferred_on the_recording_medium_through an intermediate transfer medium.
Due_to a further advancement of_a variety_of techniques as to the computer, for example,_due_to an advancement_of high-definition of the computer image, the image forming_apparatus of the electrophotographic system is_also required to_correctly_and_distinctly duplicate a fine_figure, a subtle hue change and_the like in the computer image,_and to form a high-definition image comparable_to the computer image. In order_to meet the requirement, for_example, reduction_of toner particle size has_been intended, where_a variety_of considerations have_been carried out for producing a_toner whose particle_size is about 5 μm which_is_useful for the_high-definition_of_the image.
Although_such a reduced_particle_size toner_is_useful for forming the high-definition image,_the_toner encompasses a lot of fine powders_so that there is_a_disadvantage in that transferring_efficiency is low. The reduced_particle size toner has high charge-accumulation_property and_a large_specific surface area compared to a toner for example whose particle_size is more than 5 μm,_so that adhesiveness of_the reduced_particle_size toner to_the_photoreceptor drum_and the intermediate transfer medium is strong._The reduced_particle size toner has the low_transferring efficiency and is_hard_to be transformed to the recording_medium, causing a problem that, when_the reduced particle size toner_is_used,_an amount of the toner_remaining on the photoreceptor drum and_the intermediate transfer_medium after transferring the visualized images onto_the_recording medium is increased.
In view of_such_a problem, it is suggested that,_by_spheroidizing_the toner, a contact area_between the photoreceptor drum and the_intermediate transfer medium, and the toner is so reduced_that the transferring_efficiency of the toner is_enhanced_(referring_to Japanese Examined Patent Publication JP-B2 3253228 and Japanese Unexamined_Patent Publication_JP-A 2005-257976, for_example).
In JP-B2 3253228, it is disclosed that, by defining the_shape coefficient SF-1 indicating the degree of_roundness of a toner particle as 111 to 160, the shape_coefficient SF-2 indicating the degree of irregularity of_a surface of the toner particle as_110 to 140, SF-2/SF-1_as_1 or less, and the content of_releasing_agent_as