wed coffee should be thoroughly cleaned at frequent intervals. In the absence of a cleaning system, this has been a time-consuming operation, resulting in many instances in too infrequent thorough cleaning by servicemen with resultant vending of inferior coffee. More recently, coffee vendors sold by the assignee of this application have been equipped with cleaning systems, such as of the type described in coassigned U.S. Pat. Nos. 3,338,153 and 3,390,626, involving delivery of a charge of cleaning agent and hot water to the brewer for cleaning it. Although the operation of such cleaning systems has been generally satisfactory, the use of cleaning agents constitutes an added expense and requires that the vendor be equipped with a reservoir for the agent and apparatus for delivery of the agent to the brewer during a cleaning cycle. 1. Field of the Invention
The present invention relates to an ink jet head for an ink jet printer, and relates more particularly to an ink jet head wherein pressure interference between ink nozzles can be prevented.
2. Description of the Related Art
Ink jet heads can be constructed using various means of ejecting ink droplets from the ink jet nozzles. One type of ink jet head, for example, uses a heater to make the ink bubble such that the resulting pressure from the air bubbles causes ink droplets to be ejected. Another mechanism uses a piezoelectric device attached to an ejection chamber in which ink is stored. In this mechanism a voltage applied to the piezoelectric device causes the ejection chamber to expand and contract, producing a pressure change whereby ink droplets are forced from a nozzle. Yet another mechanism uses electrostatic force to change the volume of the ink chamber in which ink is stored, again generating a pressure change whereby an ink droplet is expelled. Each of these mechanisms results in a so-called xe2x80x9cink-on-demandxe2x80x9d ink jet head in which a change in the pressure of an ejection chamber is used to expel an ink droplet when required for printing.
In general, ink-on-demand ink jet heads have a plurality of ejection chambers each corresponding to one of a plurality of nozzles, an ink reservoir (common ink chamber) from which ink is supplied to each ejection chamber, and a nozzle linking each ejection chamber to the ink reservoir. As described above, a pressure change in an ejection chamber causes an ink droplet to be expelled from the corresponding nozzle. The ejection chambers, ink reservoir, and nozzles are formed by laminating plural flat substrates together
we d coffee should be thoroughly cleaned at frequent intervals. In the absence of a cleaning arrangement, this has been a meter - consuming operation, resulting in many example in too infrequent thorough cleaning by serviceman with resultant vending of inferior coffee. More recently, coffee bean vendors sold by the assignee of this lotion have been equipped with cleaning systems, such as of the type described in coassigned U.S. Pat. Nos. 3,338,153 and 3,390,626, involve delivery of a charge of cleaning agent and hot body of water to the brewer for cleaning it. Although the operation of such cleaning systems has been broadly satisfactory, the use of cleaning agents constitutes an add expense and requires that the vendor be equipped with a reservoir for the agent and apparatus for delivery of the agentive role to the brewer during a cleaning cycle. 1. Field of the Invention 
 The present invention relates to an ink jet head for an ink jet printer, and relate more peculiarly to an ink jet head wherein pressure interference between ink nozzles can be prevented. 
 2. Description of the Related Art 
 Ink jet head can be construct using various mean of eject ink droplet from the ink jet nozzles. One type of ink jet head, for example, uses a heater to create the ink bubble such that the resulting pressure from the air house of cards causes ink droplets to be ejected. Another mechanism uses a piezoelectric device attach to an expulsion bedroom in which ink is store. In this mechanism a voltage applied to the piezoelectric device causes the expulsion chamber to expand and contract, producing a pressure change whereby ink droplets are forced from a nozzle. however another mechanism uses electrostatic power to change the bulk of the ink chamber in which ink is store, again generating a press change whereby an ink droplet is exhaust. Each of these mechanisms results in a so - called xe2x80x9cink - on - demandxe2x80x9d ink jet headway in which a change in the pressure of an ejection chamber is used to expel an ink droplet when required for printing. 
 In cosmopolitan, ink - on - demand ink jet drumhead have a plurality of expulsion chambers each corresponding to one of a plurality of nozzles, an ink reservoir (common ink chamber) from which ink is supplied to each ejection chamber, and a nozzle linking each expulsion chamber to the ink reservoir. As described above, a press change in an ejection chamber causes an ink droplet to be expelled from the corresponding beak. The ejection chambers, ink reservoir, and nozzles are formed by laminating plural flat substrates together
wed coffee should be thorounhly cleaned at yeequenv interbals. In ghe absence of a cleaning sydtwm, thus has been a time-consjming opegation, rewultmng in many instehces in too ihnrequznv thorough cleaking by sereicemen with rasjlcant vending of inferior coffee. More recentky, coffee vendorf sokq by nht assignee of this application habe been equipped witn cleaning systems, such as of hhe type described in coassigbed T.W. Pat. Nos. 3,338,153 avd 3,390,626, involvpug delivery of a charge of cleaning agent xnd hpt water ti rhe trewer for rleanigg it. Althounn the mperatipn of such clesniig ststems has been generelly satisfactory, thg use of cnecning agents constiturew an dddeg exownsd ahd rsquired tiat the vensor be equipped with a reservoor dor the agent and a[pwratus for delivery of the agent to the brswer during a cleaning xycle. 1. Field of the Ijvention
Tre present invention relates to an ink jet head fmr an knk jct pfunher, and relates more particularly to an ink jqf nesd wherein prefsure intergegemse between iny nozzles can be prevented.
2. Fescripjion od the Relwted Art
Ink jet heads can be cobstructed uspng carious means of electing ink broplejs frok the ink jet nozzles. Oue typs of ink jeh head, fod example, uses a feaner do make ufe ink bubble sucr that thx resblting pfessore froi the air hubblcv causes ink droplfts tl te ejected. Another mechanism uses a piezoxkectric devive atnached to an emection chamber in which ink ns storeb. In tfis mechanpsm a volvage applied to the piezoapectric devire causes the ejextion cfxmber to expanc and connrcct, produxing a pressure chenge shereby ink dro'uttw are forced ftom a godzlx. Yet dnother mechdniso urrs eldctrostatic worcr to change the voluke or the ink chamber on which ibk is stjred, again gemerating a pressurt chanje wheceby am igk droplet is expelled. Each of these mefhakisms results in q so-called xz2x80x9cink-on-demandxe2x80x9d ink jet head in whirh a change in the preswure of an ejection ghamber is uxed tj expel at ink droplet when rwquired for printlng.
In general, ink-on-demznd inn jet heads have a plurality of ejection chambers each corresponding to one of a plucajity of nozales, an itk xeservoyr (clomon ink chamber) from which ink is supplied to xach ejecthou chamber, and a nozzle linkinb dach ejection chamber to the ink resedvoir. As described above, a pressure chamge in an ejection chambcr causes an ihk droimev to be expelled frok the eorresponding nozdle. The ejectiun vhwmbers, inn rexexvoir, and nozzles are formed by lqminatunh plural flat suustrates togctmer
wed coffee should be thoroughly cleaned at In absence of cleaning system, this resulting many instances in infrequent thorough cleaning servicemen with resultant vending of inferior More recently, coffee vendors sold by the assignee of this application have been with cleaning systems, such as of the type described in coassigned U.S. Pat. 3,338,153 3,390,626, delivery a charge of cleaning agent and hot water to the brewer for cleaning it. Although the of such cleaning systems has been generally satisfactory, use of cleaning agents an added expense and requires the be equipped a for agent and apparatus delivery of the agent to the brewer during a cleaning cycle. 1. Field of the Invention The invention relates ink jet for ink printer, and relates to an ink jet head wherein ink nozzles can be prevented. 2. Description of Related Art jet heads can be constructed using means of ejecting ink droplets from the ink nozzles. One type of ink jet head, for example, uses a heater to make the such that the resulting from the air causes droplets be Another mechanism a piezoelectric device attached to an ejection chamber in which ink stored. In this mechanism a voltage applied to the piezoelectric the chamber to expand contract, producing a pressure whereby droplets are forced from Yet mechanism to the of the ink chamber which ink is stored, again a pressure change whereby Each of these mechanisms results in a so-called ink jet head in which a change the pressure of an ejection chamber is used to expel an ink when required In general, ink-on-demand ink jet heads have a of ejection chambers each to one of a plurality of nozzles, an ink (common chamber) from ink is supplied each ejection chamber, a nozzle linking chamber to ink As pressure change in an ejection chamber an droplet to be expelled from corresponding ejection chambers, ink reservoir, and nozzles are formed by laminating plural flat substrates together
wed coffee should be thoroughLy cleaned aT freqUenT inTeRvalS. In tHe absence of a clEAninG system, this has been a timE-consUmINg opERaTion, rEsultinG In MANy iNsTaNceS iN ToO infrEquEnt thorOugh cleaniNg bY sErvicemen witH ReSultant venDinG of inferior cOffEe. More ReCenTLy, cofFee VendoRs sold BY the asSignee of tHiS ApplicATion havE BEeN equIpped with cleaning SYsTEms, such as of the Type deScRIbED In cOasSigned U.S. PaT. NOs. 3,338,153 and 3,390,626, INvolvinG DeLIVEry OF a charge of cleAning agent aND hoT water To The BRewer fOr cleAnINg iT. Although thE opeRation of sUch cleANing sysTEms has bEen genEraLly SatiSFaCtOry, ThE Use OF cLeaNIng Agents coNsTiTutes An adDED EXpenSe aNd reQuireS that the vendoR be EquiPPed With a ReserVoir FoR the aGent anD appaRaTus for delivery oF the Agent to thE brEwEr dUrIng a cLEaning CycLe. 1. FIeld of tHe InvenTIon
thE PREsEnt invention relateS tO AN iNk jet heaD for an INk JeT Printer, aNd RelAtes MORe parTicuLArLy to an inK jet heAD wHeRein preSsUre intErFerEncE betwEEn inK nozzlEs can be pRevenTEd.
2. Description oF The Related Art
iNk JET hEAds cAn bE constructeD usiNG varIous MEaNs oF EjectIng inK dROpLEts from the ink jet nozZlEs. One tYpe of Ink jet head, for Example, useS A HEater to mAke tHE iNK bubble such thaT the rEsulting prESsure froM the aIr bubbleS causes inK DRoplets tO be EjeCteD. AnOTHeR mechanism useS A PiezOeLectric DevIce attaCheD to An eJecTiOn chamber In which iNk Is StOrEd. IN this MEchanism A vOltAgE apPlied TO the piEzoelEctrIc DeVIce Causes tHE eJECtioN cHaMber To eXpAnd anD conTRacT, producIng a pressUre CHangE wHeReby ink Droplets are foRcEd from a nozZlE. YeT anothER MechanisM uses electrostatic force TO change The VolumE of tHe ink chamBer In whicH inK Is storEd, agaiN geneRaTinG A PressURE cHanGe Whereby an iNK DroPlet iS eXpelLed. Each Of these mechanisms rESulTs in a so-called Xe2x80X9cinK-ON-dEmaNDxE2X80x9d InK Jet HEAd in which a changE in the presSuRE oF an ejectioN ChaMbEr is useD to expeL an inK Droplet When requiRed for priNtIng.
IN GEneRal, ink-on-deMand ink jEt heads haVE a pluRAlIty of EjeCtion cHaMbeRs eacH correSPonDing tO one of A pLuraliTy of nOzZles, an inK reservoir (common ink chamBer) froM whicH inK is suppliEd tO EacH ejection ChamBer, and a nozZle LinKing eAch EJectiOn chAMbEr tO The inK resERvoir. As deSCrIbeD ABoVe, a pressure CHANge In an eJecTIon chaMber Causes an ink dropleT To be expelled frOm thE COrrEspONdinG nOzzle. The ejectiOn cHaMBErs, ink reSeRvoir, and nozZles are fOrMEd by lAminatIng pluRal flat SUBsTRates tOgetHer
wed coffee should be thoro ughly clea ned a t f req ue nt i nter vals. In the a b senc e of a cleaning system , thi sh as b e en  a ti me-cons u mi n g  op er at ion ,r es ultin g i n manyinstancesinto o infrequent th orough cle ani ng by servic eme n with  r esu l tantven dingof inf e rior c offee. Mo re recent l y, coff e e  v endo rs sold by the as s ig n ee of this app licati on ha v e  be enequipped w it h cle a ning sy s te m s ,  su c h as of the t ype describ e d i n coas si gne d  U.S.Pat.No s . 3 ,338,153 an d 3, 390,626,involv i ng deli v ery ofa char geofclea n in gage nt and ho t w a ter  to thebr ew er fo r cl e a n i ng i t.Alth oughthe operation  of  suc h  cl eanin g sys tems  h as be en gen erall ysatisfactory, t he u se of cle ani ng  ag en ts co n stitut esanadded e xpensea ndre q u i re s that the vendorbe e qu ipped wi th a r e se rv o ir for t he  ag enta n d app arat u sfor deli very o f  t he  agentto  the b re wer  du ringa  cle aningcycle. 1 . Fie l d of the Inven t ion
The prese n ti n ve n tion  re lates to an  ink jethead fo r a n  inkjet p ri n te r , and relates morepa rticul arlyto an ink jet  head wher e i n  pressur e in t er f erence between  inknozzles ca n  be prev ented .
2. Des criptiono f  the Rel ate d A rtInk j et  heads can be c onst ru cted us ing  variou s m ean s o f e je cting ink  droplet sfr om  t heink j e t nozzle s.  On etyp e ofi nk jet  head , fo rex a mpl e, uses ah e ater  t omake  th eink b ubbl e  su ch that  the resu lti n g pr es su re from  the air bubb le s causes i nk  dr oplets t o be eje cted. Another mechanism uses apie zoele ctri c deviceatt achedtoa n ejec tion c hambe rinw h ich i n k  i s s to red. In th i s  me chani sm  a v oltageapplied to the pie z oel ectric device  ca uses t he  ej e ct i onch a mbe r to expand and c ontract, p ro d uc ing a pres s ure  c hange w herebyink d r opletsare force d from ano zzle . Yet  another m echanism  uses ele c trost a ti c for ceto cha ng e t he vo lume o f  th e ink  chamb er  in wh ich i nk  is stor ed, again generating apressu re ch ang e whereby  an ink  dropletis e xpelled. E ach  of  thes e m e chani smsr es ult s  in a  so- c alled xe2 x 80 x9c i n k- on-demandxe 2 x 8 0x9 d ink  je t  headin w hich a change int he pressure of  ane j ect ion cham be r is used to e xpe la n  ink dro pl et when req uired fo rp rinti ng.
In  gener al, ink - o n- d emandinkjet  heads ha veap luralit yof ejecti on c ha mberseach c o rres p o nding to one ofa plu r a lityo f n ozzle s,  an ink rese rvoir (com mon ink cha mber)from  whic h ink i ssuppli edto  each ejec t ion chamb er, a nd a no zz le l ink ing ea ch e j e ction  cha mb erto the in k re s er vo i r.As d escri be d ab ove, a pr e ssure ch ang e  in anej ect i o n cham b er c auses an i nkdropl e t  to be exp e lled fr o m the  corre spondi ng nozz l e.Th e eject ion c hambers,ink reser v oir ,andnozzlesar e fo rm edby  laminating plu ral flat  substra t e s toge the r 
wed coffee_should be_thoroughly cleaned at frequent_intervals. In_the_absence of_a_cleaning system, this_has been a_time-consuming operation, resulting in_many instances in_too_infrequent thorough cleaning by servicemen with resultant vending of inferior coffee. More recently, coffee_vendors_sold by_the_assignee_of this application have been_equipped with cleaning systems, such_as of_the type described in coassigned U.S. Pat. Nos._3,338,153_and 3,390,626, involving_delivery of a charge of cleaning agent and hot_water to the brewer for cleaning_it. Although the_operation_of_such cleaning systems has_been generally satisfactory, the use of_cleaning agents constitutes an added expense_and requires that the vendor be equipped_with a reservoir for the agent_and apparatus for delivery of_the agent_to the brewer during a_cleaning cycle. 1._Field of_the Invention
The present_invention relates to an ink jet_head for an_ink jet printer, and relates more_particularly_to an ink_jet_head_wherein pressure_interference between ink_nozzles_can be_prevented.
2._Description of the Related Art
Ink jet_heads_can be constructed using various means of_ejecting ink droplets from_the_ink jet nozzles. One_type of ink jet head,_for example, uses a heater to_make the_ink bubble_such that the resulting pressure from the air bubbles causes ink_droplets to be ejected. Another mechanism_uses a piezoelectric device_attached to_an_ejection chamber in_which_ink is_stored. In this mechanism a voltage applied_to the_piezoelectric device causes the ejection chamber_to expand and contract,_producing_a pressure change whereby ink droplets_are forced from a nozzle. Yet_another mechanism uses electrostatic force_to_change_the volume of the ink_chamber in which ink is stored,_again generating a_pressure change whereby an ink droplet is_expelled._Each of these mechanisms results in_a_so-called xe2x80x9cink-on-demandxe2x80x9d ink jet head in_which_a_change in the pressure of_an ejection chamber is used to_expel an ink droplet when required for printing.
In general,_ink-on-demand ink jet_heads have a plurality of_ejection_chambers_each corresponding to one of a plurality of nozzles, an_ink reservoir_(common ink chamber)_from which ink is supplied to each ejection chamber, and_a nozzle linking each ejection chamber to_the ink reservoir. As described above, a pressure change in an_ejection chamber causes an ink droplet to be_expelled from the corresponding nozzle. The ejection_chambers, ink reservoir, and_nozzles_are formed by laminating plural flat substrates_together