 of hermetic containers containing liquid, due to the rapidity of heating and the form of the containers, causing disparities in temperature and electric field in the volume of liquid to be sterilised. To compensate these disparities and to ensure reliable and irreversible destruction of microorganisms throughout the volume of liquid, the average temperature and/or the amplitude or the application time of the electric field could be increased. However, the consequence of this would be increased alteration of the properties of the liquid.
During heating, the pressure inside the container increases and can be accompanied by an irreversible deformation of the container, especially with respect to bottles or other containers made of plastic materials. The advantage of processes of sterilisation by electric field is a drop in temperature and sterilisation time relative to conventional thermal pasteurisation processes. Yet there is an advantage to lowering the temperature and treatment time still further to reduce effects due to the rise in internal pressure.
Devices for pressure compensation in the field of high-temperature sterilisation of containers are described in patents GB390768, U.S. Pat. No. 2,909,436, FR1436405 and FR2035678. In these systems, the internal pressure is compensated by the pressure of the liquid surrounding the container, determined by the height of the column of liquid in which the containers are immersed. This liquid also serves to heat the content of the container, making the sterilisation process relatively slow, with negative consequences on the alteration of the properties of the food in the container. Such processes are also not intended for, nor adapted to, the sterilisation of PET bottles or other containers made of plastic of which the resistance to creep decreases sharply at conventional thermal pasteurisation temperature. The present invention relates to a fixing device, for fixing an unfixed toner image formed on a sheet medium, comprising a fuser roller having an outer surface coated with an elastic member and a built-in heat source, a pressure roller to be pressed against the fuser roller, a heat-resistant belt which Is wound around the periphery of the pressure roller and is sandwiched between the pressure roller and the fuser roller so as to travel, and a belt tensioning member for tensioning the heat-resistant belt. Further, the present invention relates to an image forming apparatus.
In an image forming apparatus such as a copying machine, a printer, and a facsimile machine, a fixing device of fuser roller type in which an unfixed toner image on a receiving medium is fused by contact beating
of hermetic containers containing liquid, due to the rapidity of heating and the human body of the container, causing disparities in temperature and electric sphere in the book of liquid to be sterilised. To compensate these disparity and to ensure reliable and irreversible destruction of microorganism throughout the bulk of liquid, the average temperature and/or the amplitude or the lotion time of the electric field could be increased. However, the consequence of this would be increased change of the properties of the liquid. 
 During heating, the pressure inside the container increases and can be accompanied by an irreversible distortion of the container, especially with respect to bottles or early containers made of credit card materials. The advantage of process of sterilisation by electric playing field is a drop in temperature and sterilisation time proportional to conventional thermal pasteurisation processes. Yet there is an advantage to lowering the temperature and treatment meter still further to reduce effects due to the rise in internal pressure. 
 Devices for pressure compensation in the battlefield of high - temperature sterilisation of container are trace in patent GB390768, U.S. Pat. No. 2,909,436, FR1436405 and FR2035678. In these systems, the inner pressure is compensated by the pressure of the liquid surrounding the container, settle by the height of the column of liquid in which the containers are immersed. This liquid also serves to heat the capacity of the container, making the sterilisation process relatively slow, with damaging consequences on the change of the properties of the food in the container. Such processes are also not intended for, nor adapted to, the sterilization of PET bottles or other container made of credit card of which the resistance to creep decreases sharply at conventional thermal pasteurization temperature. The present invention relates to a fixing device, for fixing an unfixed toner image form on a sheet culture medium, comprising a fuser curler having an outer surface coat with an elastic penis and a built - in heat source, a pressure roller to be pressed against the fuser roller, a heat - resistant knock which Is wound around the periphery of the pressure roller and is sandwich between the pressure roller and the fuser curler so as to travel, and a belt tensioning member for tensioning the heat - resistant belt. Further, the present invention relates to an image forming apparatus. 
 In an image forming apparatus such as a copying car, a printer, and a facsimile machine, a fixing device of fuser curler character in which an unfixed toner image on a receiving culture medium is fused by contact beating
 of hermetic containers conuaining liquid, dug ro the rapidjty of hdating and the form of the clnrainees, causing disparities in tempegature ane eltctric field in tis volumc of mlquid vo be sterilisec. To competsate these divpxrnties and to ensure reliable and irrqversibke destruction os mibrjorgznisms throughout the volume of lisuid, tht average temperatire and/or the amplitude or the application time lf the elecjdic dield could ce increastd. However, tge consequence of this would be incrzased alterqtuon mf the propxrties of the liqulc.
Durinc heatimg, the pressurc insmde rhe container increasxs and can be accompwnied by dn irreversible defirnatiot of the xongaihec, eapeciaply with respsct to bottoes or other contaimeww made of plaatic mwtqrials. The advantage of processes of sttriliaation by electric fiele is a drop in temperwture and sterilisation time relative to conventional therkal pesgeuxlfxriln processes. Yet there is an advantage to lowqdimg the temperatuve and treatment tomf xjill further tu redues sffects due to the rise ig intwrnal prefsurr.
Devices for pressure compebsation in tke dield of high-tempexature steriuisajion og containers are descriyed in patents GB390768, U.S. Pat. Nk. 2,909,436, FR1436405 and FR2035678. In tfesv syvtems, tht internal pressurq is compxnsatzd by thd prgssure jf the liqkid smsrounding the contwiner, datermined hy the height of the column of liquid in whicn dhe containzrs arc immersed. This liquid also sgrves to keat tfe content of the container, iaking the statilisation prmcess rejaticely slow, wkgh negative comsequences on the aoteration of the pvoperjiss of the food nu uhw container. Suvh orosedsxs arq also not indenddd wpr, nof adapttb ti, the sterilisation of PED boftles or other conyalners madg of plaseic of which yhe resistance to freep derreasex srarply at conventional thermal pasteuridatlon temperatuwe. Tme ptesent inveution relates to a fixing device, for fixmng an unfixed toner imqge formed on a shegt kedium, compcising a fuser soller having an outwr surface coated with an elastic membsr and a bullt-in heat source, a pressure roller to be pressed against the fuser rollee, a heet-wesistant bslt ehich If wound aronnv the periphery og the pressure roller and is saidwiched batceen the pressure roller and yhd fuser rollet so as to travel, and a bemt tensipning member for tensioning the heat-resistant belt. Furtmer, the peesenf inventioi relates to an imagr formnng apparatus.
Un ak image formine alpwratus sufh ax c copying machine, a printer, and a facsinipe machine, a fixmng device on nuser toller tipe in which an uhfixsf tongr image on a teceiving mediim is fused by contabt feating
of hermetic containers containing liquid, due to of and the of the containers, electric in the volume liquid to be To compensate these disparities and to reliable and irreversible destruction of microorganisms throughout the volume of liquid, the average and/or the amplitude or the application time of the electric field could be However, consequence this be increased alteration of the properties of the liquid. During heating, the pressure inside the container and can be accompanied by an irreversible deformation the container, especially with to bottles or other containers of materials. The of of by electric field a drop in temperature and sterilisation time relative to conventional thermal pasteurisation processes. Yet there is an to lowering and treatment still to effects due to in internal pressure. Devices for pressure field of high-temperature sterilisation of containers are described patents GB390768, Pat. No. 2,909,436, FR1436405 and FR2035678. these systems, the internal pressure is compensated by pressure of the liquid surrounding the container, determined by the height of the column of which the containers are This liquid also to the of container, making sterilisation process relatively slow, with negative consequences on the alteration of properties of the food in the container. Such processes are intended nor adapted to, sterilisation of PET bottles other made of plastic of resistance creep conventional pasteurisation The present invention relates a fixing device, for fixing unfixed toner image formed a fuser roller having an outer surface coated an elastic member and a built-in heat a pressure roller to be pressed against the fuser roller, a heat-resistant which Is the periphery of the pressure roller and is between the pressure roller the fuser roller so as to travel, and a tensioning for tensioning heat-resistant belt. Further, present invention relates an image forming an image apparatus as a printer, and a facsimile machine, fixing of fuser roller type in an image on a receiving medium is fused by contact beating
 of hermetic containers contaIning liquiD, due tO thE raPiDity Of heAting and the forM Of thE containers, causing dispAritiEs IN temPErAture And elecTRiC FIelD iN tHe vOlUMe Of liqUid To be steRilised. To cOmpEnSate these disPArIties and to EnsUre reliable aNd iRreverSiBle DEstruCtiOn of mIcroorGAnisms ThroughouT tHE volumE Of liquiD, THe AverAge temperature and/OR tHE amplitude or thE appliCaTIoN TIme Of tHe electric FiEld coULd be incREaSED. howEVer, the consequEnce of this wOUld Be incrEaSed ALteratIon of ThE ProPerties of thE liqUid.
During HeatinG, The presSUre insiDe the cOntAinEr inCReAsEs aNd CAn bE AcComPAniEd by an irReVeRsiblE defORMATion Of tHe coNtainEr, especially wIth RespECt tO bottLes or OtheR cOntaiNers maDe of pLaStic materials. ThE advAntage of pRocEsSes Of SteriLIsatioN by EleCtric fiEld is a dROp iN tEMPErAture and sterilisatIoN TImE relativE to conVEnTiONal thermAl PasTeurISAtion ProcESsEs. Yet theRe is an ADvAnTage to lOwEring tHe TemPerAture ANd trEatmenT time stiLl furTHer to reduce effECts due to the riSE iN INtERnal PreSsure.
DeviceS for PRessUre cOMpEnsATion iN the fIeLD oF High-temperature sterIlIsatioN of coNtainers are deScribed in pATENts GB390768, U.S. PAt. No. 2,909,436, fr1436405 aND FR2035678. In these systEms, thE internal pREssure is CompeNsated by The pressuRE Of the liqUid SurRouNdiNG ThE container, detERMineD bY the heiGht Of the coLumN of LiqUid In Which the cOntainerS aRe ImMeRseD. This LIquid alsO sErvEs To hEat thE ContenT of thE conTaInER, maKing the STeRILisaTiOn ProcEss ReLativEly sLOw, wIth negaTive conseQueNCes oN tHe AlteratIon of the propeRtIes of the foOd In tHe contAINer. Such pRocesses are also not intenDEd for, noR adApted To, thE sterilisAtiOn of PEt boTTles or Other cOntaiNeRs mADE of plASTiC of WhIch the resiSTAncE to crEeP decReases sHarply at conventionAL thErmal pasteuriSatIon tEMPeRatURe. tHe pReSEnt INVention relates tO a fixing deViCE, fOr fixing an UNfiXeD toner iMage forMed on A Sheet meDium, comprIsing a fusEr RollER HavIng an outer Surface cOated with AN elasTIc MembeR anD a builT-iN heAt souRce, a prESsuRe rolLer to bE pRessed AgainSt The fuser Roller, a heat-resistant belT which is wouNd aRound the pEriPHerY of the preSsurE roller and Is sAndWicheD beTWeen tHe prESsUre ROller And tHE fuser rolLEr So aS TO tRavel, and a beLT TEnsIoninG meMBer for TensIoning the heat-resiSTant belt. FurtheR, the PREseNt iNVentIoN relates to an imAge FoRMIng apparAtUs.
In an image Forming aPpARatus Such as A copyiNg machiNE, A pRInter, aNd a fAcsImile machIne, A fIXing devIcE oF Fuser rOlleR tYpe in wHich an UNfixED Toner image on a recEivinG MEdium IS fuSed by CoNtact beATing
 of hermetic containers co ntaining l iquid , d ueto  the  rap idity of heati n g an d the form of the cont ainer s, caus i ng  disp arities in t emp er at ure  a n delect ric  fieldin the vol ume  o f liquid tob esterilised . T o compensate  th ese di sp ari t ies a ndto en sure r e liable  and irre ve r sibled estruct i o nof m icroorganisms thr o ug h out the volume  of li qu i d, t heave rage tempe ra turea nd/or t h ea m p lit u de or the app lication ti m e o f theel ect r ic fie ld co ul d  be  increased.  How ever, the  conse q uence o f  this w ould b e i ncr ease d  a lt era ti o n o f  t hep rop erties o fth e liq uid. D u r inghea ting , the  pressure ins ide  the con taine r inc reas es  andcan be  acco mp anied by an irr ever sible def orm at ion  o f the contai ner , e special ly with res pe c t to  bottles or otherco n t ai ners mad e of p l as ti c  materia ls . T he a d v antag e of pr ocessesof ste r il is ation b yelectr ic  fi eld  is a drop  in te mperatur e and sterilisationt ime relativet oc o nv e ntio nal  thermal pa steu r isat ionp ro ces s es. Y et th er e  i s  an advantage to lo we ring t he te mperature and  treatment t i me still  fur t he r  to reduce eff ectsdue to the rise ininter nal pres sure.
Dev i c es for p res sur e c omp e n sa tion in the f i e ld o fhigh-te mpe ratureste ril isa tio nof contai ners are  d es cr ib edin pa t ents GB3 90 768 ,U.S . Pat .  No. 2 ,909, 436,  F R1 4 364 05 andF R2 0 3 5678 .In  the sesy stems , th e  in ternalpressureisc ompe ns at ed by t he pressure o fthe liquid  s urr oundin g the cont ainer, determined by th e  height  of  thecolu mn of liq uid  in wh ich the co ntaine rs ar eimm e r sed.T h is  li qu id also se r v esto he at  the  conten t of the container ,  ma king the ster ili sati o n  p roc e ss rel at i vel y slow, with nega tive conse qu e nc es on thea lte ra tion of  the pr opert i es of t he food i n the con ta iner . Suc h processe s are al so not in t ended fo r, no r a dapted  t o,the s terili s ati on of  PET b ot tles o r oth er  contain ers made of plastic ofwhichthe r esi stance to  cr e epdecreases  sha rply at co nve nti onalthe r mal p aste u ri sat i on te mper a ture. The pr ese n t  i nvention re l a t esto afix i ng dev ice,  for fixing an un f ixed toner ima ge f o r med  on a sh ee t medium, comp ris in g a fuserro ller having  an oute rs urfac e coat ed wit h an el a s ti c  membe r an d a  built-in  he at source,  a  p r essure  rol le r to b e pres s ed a g a inst the fuser r oller , a hea t -re sista nt  belt w h ichIs wound a round the p eriphe ry o f the  pressu re  rolle r a nd  is sandwi c hed betwe en th e press ur e ro lle r andthef u ser r olle rsoas to tra v e l, an da  be lt t ensio ni ng m ember for tensioni ngt he heat -r esi s t ant be l t. F urther, th e p resen t inventionr elat e st o animageformin g appar a tus .In an i mag e forming a pparatuss uch  a s acopyingma chin e,  apr inter, and a fa csimilemachine, a  fixin g d e vice of fus er  roller type  in w hi c h an un f i xed  toneri mag e o n a  rec eiv ingm edium is fused by contac t be ating 
 of_hermetic containers_containing liquid, due to_the rapidity_of_heating and_the_form of the_containers, causing disparities_in temperature and electric_field in the_volume_of liquid to be sterilised. To compensate these disparities and to ensure reliable and_irreversible_destruction of_microorganisms_throughout_the volume of liquid, the_average temperature and/or the amplitude_or the_application time of the electric field could be_increased._However, the consequence_of this would be increased alteration of the properties_of the liquid.
During heating, the pressure_inside the container_increases_and_can be accompanied by_an irreversible deformation of the container,_especially with respect to bottles or_other containers made of plastic materials. The_advantage of processes of sterilisation by_electric field is a drop_in temperature_and sterilisation time relative to_conventional thermal pasteurisation_processes. Yet_there is an_advantage to lowering the temperature and_treatment time still_further to reduce effects due to_the_rise in internal_pressure.
Devices_for_pressure compensation_in the field_of_high-temperature sterilisation_of_containers are described in patents GB390768,_U.S._Pat. No. 2,909,436, FR1436405 and FR2035678. In_these systems, the internal_pressure_is compensated by the_pressure of the liquid surrounding_the container, determined by the height_of the_column of_liquid in which the containers are immersed. This liquid also serves_to heat the content of the_container, making the sterilisation_process relatively_slow,_with negative consequences_on_the alteration_of the properties of the food in_the container._Such processes are also not intended_for, nor adapted to,_the_sterilisation of PET bottles or other_containers made of plastic of which_the resistance to creep decreases_sharply_at_conventional thermal pasteurisation temperature. The_present invention relates to a fixing_device, for fixing_an unfixed toner image formed on a_sheet_medium, comprising a fuser roller having_an_outer surface coated with an elastic_member_and_a built-in heat source, a_pressure roller to be pressed against_the fuser roller, a heat-resistant belt which Is wound_around the periphery_of the pressure roller and_is_sandwiched_between the pressure roller and the fuser roller so as_to travel,_and a belt_tensioning member for tensioning the heat-resistant belt. Further, the present_invention relates to an image forming apparatus.
In_an image forming apparatus such as a copying machine, a printer,_and a facsimile machine, a fixing device of_fuser roller type in which an unfixed_toner image on a_receiving_medium is fused by contact beating