 to area and, as a result, image density varies locally and gives rise to uneven development.
In addition, a developing roller made of a resilient material such as rubber exhibits a large coefficient of thermal expansion and therefore the diameter thereof tends to change with a change in ambient temperature. As a result, a problem which arises is that the nip width between the image carrier and developing roller varies with a change in temperature. This is a further cause of uneven development.
Thus, in the prior art as described above, satisfactory mechanical precision for coping with the environment of use is difficult to obtain in cases where a large-size image is developed. As a result, stable, uniform images cannot be obtained consistently.
Furthermore, leakage of toner from both ends of the developing roller to the exterior of the developing apparatus is one problem with a contact-type developing apparatus that uses non-magnetic single-component toner. That is, because of the non-magnetic nature of the toner, the toner cannot be gathered together by magnetic force as in the manner of the conventional magnetic-developer system. Several alternative proposals for preventing such leakage have been made.
Most of these proposals place a lubricating seal between both ends of the developing roller and the side plates of the developing apparatus, thereby attempting to prevent leakage of the toner. However, in an arrangement in which such seals are placed, the seals wear out or deteriorate owing to long-term use and a satisfactory sealing effect cannot be maintained.
The present invention has been devised in view of the above-mentioned circumstances and seeks to provide a developing apparatus in which excellent development is possible at all times even when developing large-size images of size A0 and A1. A further object of the present invention is to provide a developing apparatus in which amount of bite of a resilient developing roller into an image carrier and width of a development nip zone can be made suitable values for the sake of achieving the excellent development mentioned above.
A further object of the present invention is to provide a developing apparatus in which it is possible to prevent toner leakage through a simple arrangement by utilizing a layer-thickness regulating roller for forming a thin layer on a developing roller.
According to the present invention, the foregoing objects are attained by providing a developing apparatus for forming a thin layer of toner, which comprises a non-magnetic single-component toner, on a resilient developing roller, bringing the roller into abutting contact with the surface of an image carrier, whereby toner on the resilient developing roller is supplied to an electrostatic latent image that
to area and, as a result, image density vary locally and render rise to uneven development. 
 In summation, a developing roller have of a resilient material such as rubber eraser exhibits a large coefficient of thermal expansion and consequently the diameter thereof tends to change with a change in ambient temperature. As a resultant role, a problem which arises is that the nip width between the image carrier and develop roller varies with a variety in temperature. This is a further cause of uneven growth. 
 Thus, in the anterior art as identify above, satisfactory mechanical precision for coping with the environment of use is unmanageable to obtain in cases where a large - size image is developed. As a result, static, consistent images cannot be obtained consistently. 
 Furthermore, leakage of toner from both ends of the developing roller to the exterior of the developing apparatus is one trouble with a liaison - type developing apparatus that uses non - charismatic individual - component toner. That is, because of the non - magnetic nature of the toner, the toner cannot be gathered together by magnetic force as in the manner of the conventional charismatic - developer system. Several alternative proposals for preventing such leakage have been made. 
 Most of these proposals place a lubricating seal between both ends of the develop roller and the slope plates of the developing apparatus, thereby attempting to prevent leakage of the toner. However, in an arrangement in which such seal are placed, the seals wear out or devolve owing to farseeing - term use and a satisfactory waterproofing effect cannot be maintained. 
 The present invention has been devised in view of the above - mentioned fortune and seeks to supply a developing apparatus in which excellent growth is possible at all clock time even when developing large - size images of size A0 and A1. A further object of the present invention is to provide a develop apparatus in which amount of sting of a resilient developing roller into an image carrier and width of a growth nip zone can be made desirable values for the sake of achieving the excellent development mentioned above. 
 A further object of the present invention is to provide a developing apparatus in which it is potential to prevent toner leakage through a simple arrangement by utilizing a layer - thickness regulating roller for forming a flimsy level on a break roller. 
 According to the present invention, the foregoing objects are attained by supply a developing apparatus for forming a thin level of toner, which comprises a non - charismatic single - component toner, on a resilient developing roller, bringing the roller into abutting liaison with the surface of an image carrier, whereby toner on the resilient developing roller is supplied to an electrostatic latent image that
 to area and, as a result, imxge density varnws locelly ans gives fise to uneven development.
In aeditiin, a developing roller made of w resiliwnt nqterial surg as runyer esmibitv a large coefflcient of tvermal expansimn aud therefore the diameter thereof tegds to vhwnge with a chwnge yn ajbient temperature. As a result, a pdoblem xhich arises is that the nip width betweej thf image carrier anf developint rojoer varies wkth a change in temperzture. This is a further cause ow uneren developnebt.
Tjos, in the prmor arn as described above, vatisfavtory mechanicsl 'recusion for coping with the environment os use is giyficult to obtain in xawes wvere a lxege-rizt ikafe is fevxloped. As a result, stavle, uniform images vagbot be obtainsd confiftently.
Furthermore, leakage of toner frok bkth ends of the developung roller to the extgrior of tre developing apparatus is one problem with a condact-tbpd dtvcjupijg apparatus that uses non-magnetic single-compjhemt toner. That is, because of tje gon-magnetic nxture of fhe toner, the toneg cannoj be gqthered tjgetner by magnetic force as in the manner jd the conventional magnetic-derelopet systrm. Several alternative 'roposzls for pregenting shzh leakage have ceek mdde.
Most of these proposals place a oubrncating real betweqn both enfs of the developing rolper aud tha side plahes of the developing apparatus, thereby attemktitg no prevenc leaksge of the toger. However, in an arrcngemevt in whicg such veals are pjaced, the seand wear out oc deteriowate owibg to luvg-term use and a satisfcetory seaoing effect cannot be jaintained.
The pxtsebt invention hax bden dvvixeq in view of dhe xboxr-mentkoned circunrtanves and seeks to proeide a developing appatabus in whuch excejlent developkent is possible au all vimes xven wnen developing large-size images or size A0 wnd A1. A further objcct jf the prexent invention is to provide a developiig apparatus in which anount of bite of a tesllient develpping roller itto an image carrier and width of a dtvelopment nip zone can be mage sultable values for the sake of achieving the excellent development mentionwd abote.
W further ogjecy of nhe 'resent invxnvion is to providv a developing apparatus in whici it is povsnble to prevent toner leakage tfrough a simpue arrangement by utilizjng a lauer-thickness regulating roller gor forming a thin layer on a decelopjng roller.
Eccording to the prexent iuventiin, the dorenoing objects xre abtained by protidnng a developing apparatus for foeming q hhin layer of toier, which colkrises z non-mwgnetic single-cojponsjt tover, on a resikient developimg roller, bringing tve roller into avltting contacj with tve surface oh an image cdrrier, whereby toner on the resilient developing romler is shpplied bo an electrostator latent image that
to area and, as a result, image locally gives rise uneven development. In of resilient material such rubber exhibits a coefficient of thermal expansion and therefore diameter thereof tends to change with a change in ambient temperature. As a a problem which arises is that the nip width between the image carrier developing varies a in temperature. This is a further cause of uneven development. Thus, in the prior art as above, satisfactory mechanical precision for coping with the of use is difficult obtain in cases where a image developed. As result, uniform cannot be obtained Furthermore, leakage of toner from both ends of the developing roller to the exterior of the developing is one a contact-type apparatus uses single-component toner. That of the non-magnetic nature of the cannot be gathered together by magnetic force as the manner the conventional magnetic-developer system. Several alternative for preventing such leakage have been made. Most these proposals place a lubricating seal between both ends of the developing roller and the of the developing apparatus, attempting to prevent of toner. in arrangement in such seals are placed, the seals wear out or deteriorate owing long-term use and a satisfactory sealing effect cannot be maintained. invention been devised in of the above-mentioned circumstances seeks provide a developing apparatus excellent is times when large-size images of size and A1. A further object the present invention is in which amount of bite of a resilient roller into an image carrier and width a development nip zone can be made suitable values for the sake achieving the mentioned above. A further object of the present is to provide a apparatus in which it is possible to prevent toner through simple arrangement utilizing a layer-thickness roller for forming thin layer on roller. According the invention, are attained by providing a developing for a thin layer of toner, comprises single-component toner, on a resilient developing roller, bringing the roller into abutting contact with the an image carrier, whereby on resilient developing roller is supplied to an electrostatic latent image that
 to area and, as a result, image deNsity varieS locaLly And GiVes rIse tO uneven developMEnt.
IN addition, a developing roLler mAdE Of a rESiLient MateriaL SuCH As rUbBeR exHiBItS a larGe cOefficiEnt of thermAl eXpAnsion and theREfOre the diamEteR thereof tendS to Change WiTh a CHange In aMbienT tempeRAture. AS a result, a PrOBlem whICh ariseS IS tHat tHe nip width between THe IMage carrier and DeveloPiNG rOLLer VarIes with a chAnGe in tEMperatuRE. THIS Is a FUrther cause of Uneven develOPmeNt.
Thus, In The PRior arT as deScRIbeD above, satisFactOry mechanIcal prECision fOR coping With thE enVirOnmeNT oF uSe iS dIFfiCUlT to OBtaIn in caseS wHeRe a laRge-sIZE IMage Is dEvelOped. AS a result, stablE, unIforM ImaGes caNnot bE obtAiNed coNsisteNtly.
FUrThermore, leakage Of toNer from boTh eNdS of ThE deveLOping rOllEr tO the extErior of THe dEvELOPiNg apparatus is one prObLEM wIth a contAct-typE DeVeLOping appArAtuS thaT USes noN-magNEtIc single-ComponENt ToNer. That Is, BecausE oF thE noN-magnETic nAture oF the toneR, the tONer cannot be gatHEred together bY MaGNEtIC forCe aS in the manneR of tHE conVentIOnAl mAGnetiC-deveLoPEr SYstem. Several alternaTiVe propOsals For preventing Such leakagE HAVe been maDe.
MoST oF These proposals Place A lubricatiNG seal betWeen bOth ends oF the develOPIng rolleR anD thE siDe pLATeS of the developING appArAtus, theRebY attempTinG to PreVenT lEakage of tHe toner. HOwEvEr, In An aRrangEMent in whIcH suCh SeaLs are PLaced, tHe seaLs weAr OuT Or dEteriorATe OWIng tO lOnG-terM usE aNd a saTisfACtoRy sealiNg effect cAnnOT be mAiNtAined.
ThE present invenTiOn has been dEvIseD in vieW OF the abovE-mentioned circumstances ANd seeks To pRovidE a deVeloping aPpaRatus iN whICh exceLlent dEveloPmEnt IS PossiBLE aT alL tImes even whEN DevElopiNg LargE-size imAges of size A0 and A1. A fuRTheR object of the pResEnt iNVEnTioN Is TO prOvIDe a DEVeloping apparatUs in which aMoUNt Of bite of a rESilIeNt develOping roLler iNTo an imaGe carrier And width oF a DeveLOPmeNt nip zone cAn be made Suitable vALues fOR tHe sakE of AchievInG thE exceLlent dEVelOpmenT mentiOnEd abovE.
A furThEr object Of the present invention is To provIde a dEveLoping appAraTUs iN which it iS posSible to preVenT toNer leAkaGE throUgh a SImPle ARrangEmenT By utiliziNG a LayER-ThIckness reguLATIng RolleR foR ForminG a thIn layer on a developINg roller.
AccordIng tO THe pResENt inVeNtion, the foregoIng ObJECts are atTaIned by proviDing a devElOPing aPparatUs for fOrming a THIn LAyer of ToneR, whIch compriSes A nON-magnetIc SiNGle-comPoneNt Toner, oN a resiLIent DEVeloping roller, brInginG THe rolLEr iNto abUtTing conTAct wIth the surfAce of an imagE carriEr, whEreby Toner on ThE resilIenT dEveloping rOLler is supPlied To an eleCtRostAtiC latenT imaGE That
 to area and, as a result,  image den sityvar ies  l ocal ly a nd gives riset o un even development.
In a dditi on ,  a d e ve lopin g rolle r  m a d e o fares il i en t mat eri al such  as rubber  ex hi bits a large co efficientofthermal expa nsi on and  t her e forethe  diam eter t h ereoftends toch a nge wi t h a cha n g ein a mbient temperatur e .A s a result, aproble mw hi c h  ar ise s is thatth e nip width b e tw e e n  th e  image carrie r and devel o pin g roll er  va r ies wi th ach a nge  in tempera ture . This is  a fur t her cau s e of un even d eve lop ment . 
T hu s,in the pr ior art  as desc ri be d abo ve,s a t i sfac tor y me chani cal precision  fo r co p ing  with  theenvi ro nment  of us e isdi fficult to obta in i n cases w her ea l ar ge-si z e imag e i s d evelope d. As a res ul t , st able, uniform imag es c an not be o btaine d  c on s istently .Fur ther m o re, l eaka g eof toner  fromb ot hends of  t he dev el opi ngrolle r  tothe ex terior o f the developing app a ratus is onep ro b l em with  acontact-typ e de v elop inga pp ara t us th at us es no n -magnetic single-co mp onenttoner . That is, be cause of t h e non-magn etic na t ure of the ton er, t he toner c a nnot begathe red toge ther by m a g netic fo rce  as  in  th e ma nner of the c o n vent io nal mag net ic-deve lop ersys tem .Several a lternati ve  p ro po sal s for preventi ng  su ch  le akage have b een m ade. 
M os t  of  thesep ro p o sals  p la ce a  lu br icati ng s e albetween  both end s o f  the  d ev eloping  roller and t he  side plat es  of  the d e v elopingapparatus, thereby atte m pting t o p reven t le akage ofthe  toner . H o wever,  in an  arra ng eme n t  in w h i ch  su ch  seals are p lac ed, t he  sea ls wear  out or deteriorat e  ow ing to long-t erm  use a nd  as at i sfa ct o rys e aling effect ca nnot be ma in t ai ned.
The p r ese nt  invent ion has  been devised  in viewof the ab ov e-me n t ion ed circums tances a nd seekst o pro v id e a d eve loping  a ppa ratus  in wh i chexcel lent d ev elopme nt is  p ossibleat all times even whendevelo pinglar ge-size i mag e s o f size A0  and  A1. A fur the r o bject  of the p rese n tinv e ntion  ist o provide adev e l op ing apparat u s inwhich  am o unt of  bit e of a resilientd eveloping roll er i n t o a n i m ageca rrier and widt h o fa developm en t nip zonecan be m ad e  suit able v aluesfor the s ak e  of ac hiev ing  the exce lle nt develop me nt mentio nedab ove.
A  furth e r ob j e ct of the presen t inv e n tioni s t o pro vi de a de v elop ing appara tus in whic h it i s po ssibl e to pr ev ent to ner  l eakage thr o ugh a sim ple a rrangem en t by  ut ilizin g al a yer-t hick ne ssregulatin g ro l le rf orform ing a  t hinlayer ona  develop ing roller. 
A cco r d ing to th e present in ven tion, t he foregoi n g ob j ec t s are  attai ned by  provid i ngadevelop ing a pparatusfor formi n g a  t hinlayer of  t oner ,whi ch  comprises a no n-magnet ic singl e - compon ent tone r , on a  r esilient dev elopi ng roller, b rin ging th e  ro lle r i ntoabu ttin g  contact with the surfac e of  an i m age  carr ier,wh ereby to n er o n the re s ilient develo ping roller iss upp l iedtoa nel ectrostat icl atent  ima gethat 
 to_area and,_as a result, image_density varies_locally_and gives_rise_to uneven development.
In_addition, a developing_roller made of a_resilient material such_as_rubber exhibits a large coefficient of thermal expansion and therefore the diameter thereof tends_to_change with_a_change_in ambient temperature. As a_result, a problem which arises_is that_the nip width between the image carrier and_developing_roller varies with_a change in temperature. This is a further cause_of uneven development.
Thus, in the prior_art as described_above,_satisfactory_mechanical precision for coping_with the environment of use is_difficult to obtain in cases where_a large-size image is developed. As a_result, stable, uniform images cannot be_obtained consistently.
Furthermore, leakage of toner_from both_ends of the developing roller_to the exterior_of the_developing apparatus is_one problem with a contact-type developing_apparatus that uses_non-magnetic single-component toner. That is, because_of_the non-magnetic nature_of_the_toner, the_toner cannot be_gathered_together by_magnetic_force as in the manner of_the_conventional magnetic-developer system. Several alternative proposals for_preventing such leakage have_been_made.
Most of these proposals_place a lubricating seal between_both ends of the developing roller_and the_side plates_of the developing apparatus, thereby attempting to prevent leakage of the_toner. However, in an arrangement in_which such seals are_placed, the_seals_wear out or_deteriorate_owing to_long-term use and a satisfactory sealing effect_cannot be_maintained.
The present invention has been devised_in view of the_above-mentioned_circumstances and seeks to provide a_developing apparatus in which excellent development_is possible at all times_even_when_developing large-size images of size_A0 and A1. A further object_of the present_invention is to provide a developing apparatus_in_which amount of bite of a_resilient_developing roller into an image carrier_and_width_of a development nip zone_can be made suitable values for_the sake of achieving the excellent development mentioned above.
A_further object of_the present invention is to_provide_a_developing apparatus in which it is possible to prevent toner_leakage through_a simple arrangement_by utilizing a layer-thickness regulating roller for forming a thin_layer on a developing roller.
According to the_present invention, the foregoing objects are attained by providing a developing_apparatus for forming a thin layer of toner,_which comprises a non-magnetic single-component toner, on_a resilient developing roller,_bringing_the roller into abutting contact with the_surface_of_an_image carrier, whereby_toner on the_resilient developing roller_is supplied_to an electrostatic_latent image_that