CA1093137A - Piezoelectrically operated printer heads - Google Patents
Piezoelectrically operated printer headsInfo
- Publication number
- CA1093137A CA1093137A CA256,830A CA256830A CA1093137A CA 1093137 A CA1093137 A CA 1093137A CA 256830 A CA256830 A CA 256830A CA 1093137 A CA1093137 A CA 1093137A
- Authority
- CA
- Canada
- Prior art keywords
- printer head
- ink
- passages
- jet
- printer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/135—Nozzles
- B41J2/14—Structure thereof only for on-demand ink jet heads
- B41J2/14201—Structure of print heads with piezoelectric elements
- B41J2/1429—Structure of print heads with piezoelectric elements of tubular type
Landscapes
- Particle Formation And Scattering Control In Inkjet Printers (AREA)
- Ink Jet (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A piezoelectrically operated printer head for ink-jet printers is provided. The head comprises a body portion having a plurality of compression chambers arranged therein. These chambers are in the form of ink-jet passages, the exit orifices of which lie on a common plate. Ink is ejected through respective orifices by means of piezo-electrically operated drive elements which encircle respective passa-ges along part of their length. The distance of the drive elements from said common plane is such as to permit said passages to extend radia-lly therefrom.
A piezoelectrically operated printer head for ink-jet printers is provided. The head comprises a body portion having a plurality of compression chambers arranged therein. These chambers are in the form of ink-jet passages, the exit orifices of which lie on a common plate. Ink is ejected through respective orifices by means of piezo-electrically operated drive elements which encircle respective passa-ges along part of their length. The distance of the drive elements from said common plane is such as to permit said passages to extend radia-lly therefrom.
Description
109;~3~
The present invention r~late~ t~ p:iez~ele~tric~lly operated printer neads for ink-jet printe~s.
From American Patent Specification No. 3~2gg~030, an electric-! ally operated printer unit is known in which a printing jet is made to execute mechanical vibration by means of piezoelectric drive ele-ments and in so doing to eject printing liquid in droplet forrn The-se droplets are deflected under the effect of an electric field, to form characters in the rhythm o~ operat:ion of a character generator.
- In order with such printer units to achieve an adequately high io prlnting speed accompanied with sufficient ink saturation on the part of the characters recorded in this way, the frequency of release of .. , the individuai droplets must be extrernely high This extrernely high release frequency means that the overall unit is relatively highly susceptible to breakdown. Also, synchronising devices are required which are themselves susceptible to breakdown, these devices synchro-nising each individual droplet with the associated deflection voltage.
When, s disclosed in German Patent Specification 03 2,262,106, several printer units are combined to form a single printer head, -which is moved in the manner of a mosaic printer head along the prin-tlng line of a data carrier, each grid point being assigned a ~iezo-electrically operated printer jet (in this case a piezoelectric crys-tal transducer which acts upon a diaphragm and thus develops in a compression chamber the re~uisite pressure to release an ink droplet) the head must be especiall~ de~iyned to ovcrcorne tllo a~orelnen~iorled difficulties.
,.
These difficultles re.sult ~rom the phy~;lcal cJi.mensions o~ ~he individual plezoelectrlc~lly operatcd j~ts and thelr ~rlvc arrangem-ents, which must be grouped to~cthcr ln accordancc ~J:Ith the slæe of the printing grid. The frequent changc~ occurring in printlng opera-
The present invention r~late~ t~ p:iez~ele~tric~lly operated printer neads for ink-jet printe~s.
From American Patent Specification No. 3~2gg~030, an electric-! ally operated printer unit is known in which a printing jet is made to execute mechanical vibration by means of piezoelectric drive ele-ments and in so doing to eject printing liquid in droplet forrn The-se droplets are deflected under the effect of an electric field, to form characters in the rhythm o~ operat:ion of a character generator.
- In order with such printer units to achieve an adequately high io prlnting speed accompanied with sufficient ink saturation on the part of the characters recorded in this way, the frequency of release of .. , the individuai droplets must be extrernely high This extrernely high release frequency means that the overall unit is relatively highly susceptible to breakdown. Also, synchronising devices are required which are themselves susceptible to breakdown, these devices synchro-nising each individual droplet with the associated deflection voltage.
When, s disclosed in German Patent Specification 03 2,262,106, several printer units are combined to form a single printer head, -which is moved in the manner of a mosaic printer head along the prin-tlng line of a data carrier, each grid point being assigned a ~iezo-electrically operated printer jet (in this case a piezoelectric crys-tal transducer which acts upon a diaphragm and thus develops in a compression chamber the re~uisite pressure to release an ink droplet) the head must be especiall~ de~iyned to ovcrcorne tllo a~orelnen~iorled difficulties.
,.
These difficultles re.sult ~rom the phy~;lcal cJi.mensions o~ ~he individual plezoelectrlc~lly operatcd j~ts and thelr ~rlvc arrangem-ents, which must be grouped to~cthcr ln accordancc ~J:Ith the slæe of the printing grid. The frequent changc~ occurring in printlng opera-
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tion between the phases of accele~at;on and decel~tion, e.g. a sta-~- rt-stop operation~ also means that the printer head as seen as a whole must have the lowest possible mass.
An object of the present invention is to provide a piezoelect-` - rically operated printer head for ink-operated rnosaic printer units, -~ in which a plurality of printing jets are accomrnodated whilst maintai-`~ ning the external dimensions and mass at the lowe~t possible figure.
The overall printer head should be simple and inexpensive to manufac-~ ture, easy to service and should in particular be insensitive to pre-- 10 ssure fluctuations in the ink supply system~
~ . .
Accordingly, this invention consists in a piezoelectrically operated printer head for ink-jet printers said head comprising a - printer head body having disposed therein a plurality of compression chambers in the form of ink-jet passages having exit orifices which lie on a common plane, each of which passages is encircled along part of its length by a piezoelectrically operated drive element, wherein sald ink-jet passages are rectilinear and extend radially from said plane.
~ At least the printer head body, which supports the printing je-`~ 20 ts~ is preferably manufactured by the in situ casting of the drive .
`; elements whilst at the same time forming ~he ink passages.
.:
` ~ By means of;the invention, it is possible to design a printer head having thé requisite closely spaced jet orifice grid interval for character formation~ and to rnanuactur~ it in a relatively simp-~ , ~" .. :... .
le manner using casting tcchnlqu~; ln thl~ way~ th~ prlntcr h~a~ is made particularly robust Vi~ a-vL~ moch;Jnlcal ~ff~3ct~, b~causo b~twe-en the indivldual printlng ~o~ no rolatlv~ movern~nt~ can occur, mo-vements o a kind which would othorwl~;e rnake thcrn~elvcs felt in the form of an impairment o~ the prln~ quallty. The ovcrall printer head ,: . .: ,' , . ;. :, , .
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has a very low rnass~ is highly resislant to breakdown and is wear resistant.
.
Conveniently, the exit or'ifices of th~ ink-jet pasC;ages are co-" vered by a plate having a plurality of bores disposed therein, the ~ number of bore.q corresponding to the num~er o~ ink-jet passages.
-~` This plate is detachably fixed to the printer head body and can the-:`
refore, if required, be readily exchanged and cleaned.
~, . . .
~' ~ - - In order to render the printer head particularly insensitive to .~ .
pressure fluctuations in the ink-supply system, all the ink passages are preferably arranged to be supplied with ink through a capillary filter device which is common to all passages. This obviates the ne-cessity of providing a separate filter in each ink passaye. The ca-plllary filter device may comprise a throttle plate madé of a synthe-tic resin material and containing narrow bores, with a clos~rnesh grid arranged between the throttle plate and the ink passage. These nar-row bores are each assigned to a respective ink passage and will pre- ~-vent~fluctuations in pressure occurring' in a distributer device, whi- ~
ch is also integrated into the printer head, from having any effect '-.~ , on the printing jets. The close-mesh grid, in turn, serves as a non-20~ retu'rn device so that should air enter the ink passages, there is no ' ` risk of the ink supply system running empty.
An exemplary embodiment of the invention will now be described with reference` to'the accompanying diagrammatic drawings; in which :-, . . s~
'~ ~ Figure l shows diagrammatlcally an~ in section a printer head , , , ~ , ~ for an ink-operated mosaici prlntcr;
~ ~ , . . .
Fiyure 2 is a dia~ramm~tlc ~ront elevatior)al view o~ the prin-ter head ~hown in Figure l; and F'i~ure 3 i~ a diagrarnmatlc fra~m~ntary vie~l of th~ jet plate on larger sCale.
;" ' '~3 ,. ~ ,.
:, . . .. .
., ~ ,, 10~3~i ~7 A pie~oelectrically operated p~inter head is ~rrarlqed or rno~
vement along the printing line of a data carrier 1 ~y tr~e~ns of a dev-ice not shown and to be driven, at the sarne tirne~ by a character ge-nerator (not shown) in a manner dependent upon the characters to be printed. The printer head body 2 corrlprises single elernent cac~ ~orn a dielectric synthetic re in material. Arranged in the printer head body 2 are a plurality o passages 3 desigrled to receive printing li-quid. The ink passages 3 are tapered conically at one end thereof and terminate at the data carrier end in discharge orifices 4, which are arranged in two rows. The other ends of the passages 3 communi-;`~ cate through restricted feeders with the ink supply system. The ink passages 3 are arranged within the printer head hody 2 in such a fa-shion that they radiate in a straight line away from the printing 1G- .
cation in the manner of spokes. The passages are arranged on two le-vels which are in turn arranged at an acute angle to one another.
, . . .
- Such an arrangement is necessary in order to form a m~saic printer ; head, and is made possible by the fact that the piezoelectric drive elements each of which comprises a ceramic tube 5 which encloses its .
respective ink passage along part of the length thereof, are arranged ,. ~ ~ . . , at such an interval from the discharge orifices 4 that the tubes do not physically interfere with one another.
Arranged over the discharge orifices 4 ~f the ink passages 3 is a jet plate 6 having a plurality of mutually parallel jet bores 7 di-, sposed therein~ the number of said bores correspondincJ to the numberof ink pas;sages 3. By virtu~ o~ khelr nhap~ these )et bore3 7 det-ermine the si7~e of the lnk dropl~t~ ~ c~ct~d frolrl rcsp~ctlv~ orifi-ces and th~ di~ection in which ~al~ droplet~ arc c~ect~d. The ~et plate 6 is macle o~ metal and the narrow ~ot bc3res 7 are forrned by me-ans of laser beams or by means o~ electroeros10n technLques. In this 2,0 ;: ~
` 1~3~137 context, manufacture of the bores 7 by electro-ero~ion technlques is -~ particularly advantageous. When applying such t~chnlques, the jet - ~ opening~ are ~irst coarsely etched out and then reduced in ~iz~ ~y plating the walls of the bores with nickel~ Particularll suitable~
burr-free, paraliél openlngs are obtained in khis ~Jay rhe plate 6 , ~ ~ is remova~ly attached to the printer head body 2, by rrle~ns of screws .
~:: 9.
:
The reference numeral 10 identifies an ink distributor device lO which forms part of the ink supply system of the printer. The di-~10 stributor 10 is also integrated with the printer head. The ink pas-sages 3 communicate with the distributor 10 through a capillary fil-.~ :.
ter device ll, 12, 13, which prevents mutual interference between theindividual printing jets and at the same tirne ensures that pressure ` fluctuations developing in the ink supply systern will have no effect on the printing jets.
, The capillary filter device comprises a throttle plate 11 whi-ch is cast from a synthetic resin material and has disposed therein . , a number of openings 12 which corresponds with the number of ink passages. The openings 12 have a diameter of approximately 350 ~m.
By means~of these openings 12, pressure peaks in the ink supply sys-.
tem,~such as those caused, for example, by the acceleration and dece-leration forces acting upon the printer head, are cancelled. Betwe-~- en the throttle plate 11 and the ink pas`sages 3 there is arranged a close~mesh grid 13 of steel or F~ynthc-tJc rc~in mat~rlal. ~;h~ grlcl 13 exte~s over thé whole area of th~ throttle platQ 11 ancl has a me-,: ~
sh size of approximat~ly 35~rn ~o a~ to provlde a caplllary effect.
The grid will act as a non-r~turn d~vlcc, to prcv~nt alr Erom enter .; . .
ing the ink supply ~y~tem through the ink pas3age3 3.
The re~erence numeral 14 lcientifie~ an air-bubble 1~ which Ls . ',0 : ~ .
- .: , ~ , , :, , ~, , ~" : .. . ..
,, " , , ,, , ~
, ; , , ; , , , ; , . .. . .
-~0~137 ' , formed when the clistrihut:or 10 is filled to the re(~uislte level with ink and which is e~fective to further dampen pressure peaks ~auseSd in the ink-supply system during a start-st~p op~-rat;~n.
; In a print~ng operation, each jet sel~cting or drive element 5 is driven, via a plug-in ~ontact 15 cast in ~itu in the printer head 2 by a character generator not shown. To this end, in the illustrat-ed embodiment, the drive element 5 is provided externally with a me-`~ tal layer which serves as an electrode. A further electrode cornpri-ses a protectivé tube 16 arranyed inside the drive elernent 5. This protective tube 16 is electrically conductive and is fixed to the dr-' ive element 5 with an electric conductive adhesive. The adhesive is totally impermeable with respect to the ink'and therefore s~rves to prevent ink from penetrating the cerarnic mater`ial o the drive elerne-nt and producing a short-circuit there. Each individual drive eleme-nt 5 is so operated that the pulses which lead to the contraction th-ereof ( and therefore to the ejection of ink droplets) are applled to the external electrode of the ceramic tube 5, the protective tube 16 ~serving as an internal electrode and being permanently earthed. With such an arrangement no insulation need be provided between the prote-` 20 ctive tube 16, serving as the internal electrode, and the ink, no ca-pacitances which'might affect the efficiency of the drive element ~' can devé!op between the ink and the ceramic tub'e 5.
:
When there is used in the printer head a cerarnic tube 5 of such dimensions that the quotLent of the wall thickne~.~; of the tube dlvi-' ded by its mean d:iameter Ls cqual to ttle PolJ~sc)n'u ratlo o~ the cer-'~ ~ amic material u~ed~ then the drLve elem~nt~ ldc~lly ~ult~d fo~ the manufacture of the printer head b~l c,3s~ln~3. Wlth a clrLve ~lement so dimensioned only the int~rnal dlam~k~r o ttle tube wlll changc in dimension when the drive element is excited, whil~t th~ external dia-; -30 - 7 _ ;- :
~:,:, , - - : . . , , . , :.
0'3~3~
¦ meter remains the sarne. Thls rrleans that even durincJ lenythy printi,-:, , ~ ng operation, the drive element 5 cannot bec~m~ detached from the ; surrounding dielectric synthetic material. Furtherrnore, ~hen the ce-ramic tubé 5 contracts no darnaging mechanical stresse,s can d~velop between the cerarriic tube 5 and the surroundiny dielectric material~
so that,the ~ull de~ormation energy o~ thè ceramic tube is passed on ~ .
to the ink contained in the ink passages 3 and is thus available in toto at the jet plate 6.
As already illustrated the entire printer head 1 can be produ-:~
~ 10 ced in a simple fashion by a casting operation. To this end, the ce-. ~
ramic tubes 5 serving as drive elements and housing the protective tubes 16 are slipped over metal mandrels or pins prior to casting th-ese pins being introduced into the casting mould cornplete with the i ~ , drive elements. A~ter the dielectric synthetic material has hardened~
~` ~ ~ :
;~ ~ the pins or mandrels are removed. The resultant cavities 3 act as compression chambers for the drive elements 5, At the same time as 'the drive elements 5, the leads required to drive the individual ele-ments, along with an associated pluy-in contact 15 projecting out of the printer head, are cast in situ as well.
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tion between the phases of accele~at;on and decel~tion, e.g. a sta-~- rt-stop operation~ also means that the printer head as seen as a whole must have the lowest possible mass.
An object of the present invention is to provide a piezoelect-` - rically operated printer head for ink-operated rnosaic printer units, -~ in which a plurality of printing jets are accomrnodated whilst maintai-`~ ning the external dimensions and mass at the lowe~t possible figure.
The overall printer head should be simple and inexpensive to manufac-~ ture, easy to service and should in particular be insensitive to pre-- 10 ssure fluctuations in the ink supply system~
~ . .
Accordingly, this invention consists in a piezoelectrically operated printer head for ink-jet printers said head comprising a - printer head body having disposed therein a plurality of compression chambers in the form of ink-jet passages having exit orifices which lie on a common plane, each of which passages is encircled along part of its length by a piezoelectrically operated drive element, wherein sald ink-jet passages are rectilinear and extend radially from said plane.
~ At least the printer head body, which supports the printing je-`~ 20 ts~ is preferably manufactured by the in situ casting of the drive .
`; elements whilst at the same time forming ~he ink passages.
.:
` ~ By means of;the invention, it is possible to design a printer head having thé requisite closely spaced jet orifice grid interval for character formation~ and to rnanuactur~ it in a relatively simp-~ , ~" .. :... .
le manner using casting tcchnlqu~; ln thl~ way~ th~ prlntcr h~a~ is made particularly robust Vi~ a-vL~ moch;Jnlcal ~ff~3ct~, b~causo b~twe-en the indivldual printlng ~o~ no rolatlv~ movern~nt~ can occur, mo-vements o a kind which would othorwl~;e rnake thcrn~elvcs felt in the form of an impairment o~ the prln~ quallty. The ovcrall printer head ,: . .: ,' , . ;. :, , .
; ,;, , . ,~ .~ , . , ,';~ ' , ,.
': ,: , ' ' 0~3~37 .
has a very low rnass~ is highly resislant to breakdown and is wear resistant.
.
Conveniently, the exit or'ifices of th~ ink-jet pasC;ages are co-" vered by a plate having a plurality of bores disposed therein, the ~ number of bore.q corresponding to the num~er o~ ink-jet passages.
-~` This plate is detachably fixed to the printer head body and can the-:`
refore, if required, be readily exchanged and cleaned.
~, . . .
~' ~ - - In order to render the printer head particularly insensitive to .~ .
pressure fluctuations in the ink-supply system, all the ink passages are preferably arranged to be supplied with ink through a capillary filter device which is common to all passages. This obviates the ne-cessity of providing a separate filter in each ink passaye. The ca-plllary filter device may comprise a throttle plate madé of a synthe-tic resin material and containing narrow bores, with a clos~rnesh grid arranged between the throttle plate and the ink passage. These nar-row bores are each assigned to a respective ink passage and will pre- ~-vent~fluctuations in pressure occurring' in a distributer device, whi- ~
ch is also integrated into the printer head, from having any effect '-.~ , on the printing jets. The close-mesh grid, in turn, serves as a non-20~ retu'rn device so that should air enter the ink passages, there is no ' ` risk of the ink supply system running empty.
An exemplary embodiment of the invention will now be described with reference` to'the accompanying diagrammatic drawings; in which :-, . . s~
'~ ~ Figure l shows diagrammatlcally an~ in section a printer head , , , ~ , ~ for an ink-operated mosaici prlntcr;
~ ~ , . . .
Fiyure 2 is a dia~ramm~tlc ~ront elevatior)al view o~ the prin-ter head ~hown in Figure l; and F'i~ure 3 i~ a diagrarnmatlc fra~m~ntary vie~l of th~ jet plate on larger sCale.
;" ' '~3 ,. ~ ,.
:, . . .. .
., ~ ,, 10~3~i ~7 A pie~oelectrically operated p~inter head is ~rrarlqed or rno~
vement along the printing line of a data carrier 1 ~y tr~e~ns of a dev-ice not shown and to be driven, at the sarne tirne~ by a character ge-nerator (not shown) in a manner dependent upon the characters to be printed. The printer head body 2 corrlprises single elernent cac~ ~orn a dielectric synthetic re in material. Arranged in the printer head body 2 are a plurality o passages 3 desigrled to receive printing li-quid. The ink passages 3 are tapered conically at one end thereof and terminate at the data carrier end in discharge orifices 4, which are arranged in two rows. The other ends of the passages 3 communi-;`~ cate through restricted feeders with the ink supply system. The ink passages 3 are arranged within the printer head hody 2 in such a fa-shion that they radiate in a straight line away from the printing 1G- .
cation in the manner of spokes. The passages are arranged on two le-vels which are in turn arranged at an acute angle to one another.
, . . .
- Such an arrangement is necessary in order to form a m~saic printer ; head, and is made possible by the fact that the piezoelectric drive elements each of which comprises a ceramic tube 5 which encloses its .
respective ink passage along part of the length thereof, are arranged ,. ~ ~ . . , at such an interval from the discharge orifices 4 that the tubes do not physically interfere with one another.
Arranged over the discharge orifices 4 ~f the ink passages 3 is a jet plate 6 having a plurality of mutually parallel jet bores 7 di-, sposed therein~ the number of said bores correspondincJ to the numberof ink pas;sages 3. By virtu~ o~ khelr nhap~ these )et bore3 7 det-ermine the si7~e of the lnk dropl~t~ ~ c~ct~d frolrl rcsp~ctlv~ orifi-ces and th~ di~ection in which ~al~ droplet~ arc c~ect~d. The ~et plate 6 is macle o~ metal and the narrow ~ot bc3res 7 are forrned by me-ans of laser beams or by means o~ electroeros10n technLques. In this 2,0 ;: ~
` 1~3~137 context, manufacture of the bores 7 by electro-ero~ion technlques is -~ particularly advantageous. When applying such t~chnlques, the jet - ~ opening~ are ~irst coarsely etched out and then reduced in ~iz~ ~y plating the walls of the bores with nickel~ Particularll suitable~
burr-free, paraliél openlngs are obtained in khis ~Jay rhe plate 6 , ~ ~ is remova~ly attached to the printer head body 2, by rrle~ns of screws .
~:: 9.
:
The reference numeral 10 identifies an ink distributor device lO which forms part of the ink supply system of the printer. The di-~10 stributor 10 is also integrated with the printer head. The ink pas-sages 3 communicate with the distributor 10 through a capillary fil-.~ :.
ter device ll, 12, 13, which prevents mutual interference between theindividual printing jets and at the same tirne ensures that pressure ` fluctuations developing in the ink supply systern will have no effect on the printing jets.
, The capillary filter device comprises a throttle plate 11 whi-ch is cast from a synthetic resin material and has disposed therein . , a number of openings 12 which corresponds with the number of ink passages. The openings 12 have a diameter of approximately 350 ~m.
By means~of these openings 12, pressure peaks in the ink supply sys-.
tem,~such as those caused, for example, by the acceleration and dece-leration forces acting upon the printer head, are cancelled. Betwe-~- en the throttle plate 11 and the ink pas`sages 3 there is arranged a close~mesh grid 13 of steel or F~ynthc-tJc rc~in mat~rlal. ~;h~ grlcl 13 exte~s over thé whole area of th~ throttle platQ 11 ancl has a me-,: ~
sh size of approximat~ly 35~rn ~o a~ to provlde a caplllary effect.
The grid will act as a non-r~turn d~vlcc, to prcv~nt alr Erom enter .; . .
ing the ink supply ~y~tem through the ink pas3age3 3.
The re~erence numeral 14 lcientifie~ an air-bubble 1~ which Ls . ',0 : ~ .
- .: , ~ , , :, , ~, , ~" : .. . ..
,, " , , ,, , ~
, ; , , ; , , , ; , . .. . .
-~0~137 ' , formed when the clistrihut:or 10 is filled to the re(~uislte level with ink and which is e~fective to further dampen pressure peaks ~auseSd in the ink-supply system during a start-st~p op~-rat;~n.
; In a print~ng operation, each jet sel~cting or drive element 5 is driven, via a plug-in ~ontact 15 cast in ~itu in the printer head 2 by a character generator not shown. To this end, in the illustrat-ed embodiment, the drive element 5 is provided externally with a me-`~ tal layer which serves as an electrode. A further electrode cornpri-ses a protectivé tube 16 arranyed inside the drive elernent 5. This protective tube 16 is electrically conductive and is fixed to the dr-' ive element 5 with an electric conductive adhesive. The adhesive is totally impermeable with respect to the ink'and therefore s~rves to prevent ink from penetrating the cerarnic mater`ial o the drive elerne-nt and producing a short-circuit there. Each individual drive eleme-nt 5 is so operated that the pulses which lead to the contraction th-ereof ( and therefore to the ejection of ink droplets) are applled to the external electrode of the ceramic tube 5, the protective tube 16 ~serving as an internal electrode and being permanently earthed. With such an arrangement no insulation need be provided between the prote-` 20 ctive tube 16, serving as the internal electrode, and the ink, no ca-pacitances which'might affect the efficiency of the drive element ~' can devé!op between the ink and the ceramic tub'e 5.
:
When there is used in the printer head a cerarnic tube 5 of such dimensions that the quotLent of the wall thickne~.~; of the tube dlvi-' ded by its mean d:iameter Ls cqual to ttle PolJ~sc)n'u ratlo o~ the cer-'~ ~ amic material u~ed~ then the drLve elem~nt~ ldc~lly ~ult~d fo~ the manufacture of the printer head b~l c,3s~ln~3. Wlth a clrLve ~lement so dimensioned only the int~rnal dlam~k~r o ttle tube wlll changc in dimension when the drive element is excited, whil~t th~ external dia-; -30 - 7 _ ;- :
~:,:, , - - : . . , , . , :.
0'3~3~
¦ meter remains the sarne. Thls rrleans that even durincJ lenythy printi,-:, , ~ ng operation, the drive element 5 cannot bec~m~ detached from the ; surrounding dielectric synthetic material. Furtherrnore, ~hen the ce-ramic tubé 5 contracts no darnaging mechanical stresse,s can d~velop between the cerarriic tube 5 and the surroundiny dielectric material~
so that,the ~ull de~ormation energy o~ thè ceramic tube is passed on ~ .
to the ink contained in the ink passages 3 and is thus available in toto at the jet plate 6.
As already illustrated the entire printer head 1 can be produ-:~
~ 10 ced in a simple fashion by a casting operation. To this end, the ce-. ~
ramic tubes 5 serving as drive elements and housing the protective tubes 16 are slipped over metal mandrels or pins prior to casting th-ese pins being introduced into the casting mould cornplete with the i ~ , drive elements. A~ter the dielectric synthetic material has hardened~
~` ~ ~ :
;~ ~ the pins or mandrels are removed. The resultant cavities 3 act as compression chambers for the drive elements 5, At the same time as 'the drive elements 5, the leads required to drive the individual ele-ments, along with an associated pluy-in contact 15 projecting out of the printer head, are cast in situ as well.
20;
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Claims (17)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A piezoelectrically operated printer head for ink-jet printers said head comprising a printer head body having disposed therein a plurality of compression chambers in the form of ink-jet passages having exit orifices which lie on a common plane, each of which passages is encircled along part of its length by a piezoelectrically operated drive element, wherein said ink-jet passages are rectilinear and extend radially from said plane
2. A printer head as claimed in Claim 1, wherein each of said drive elements is arranged at a predetermined distance from said common plane.
3. A printer head as claimed in Claim 1, wherein at least the printer head body accommodating the printing jets is a single cast body with said drive elements having been cast in situ therein whilst at the same time form ing the ink-jet passages.
4. A printer head as claimed in Claim 1, wherein the exit orifices are covered by a plate having a plurality of mutually parallel bores disposed therein, the number of said bores corresponding to the number of ink-jet passages.
5. A printer head as claimed in Claim 4, wherein the plate is detach-ably fixed to the printer head body.
6. A printer head as clalmed in Clalm 1, wherein it further comprises a capillary filter device through which the ink-jet passages are supplied with ink.
7. A printer head as claimed in Claim 6, wherein the capillary filter device comprises a throttle plate having narrow openings disposed therein, and a close-mesh grid arranged between the throttle plate and the ink passages.
8. A printer head as claimed in any one of Claims 1 to 3, which includes a plug-in contact for each of the drive elements, cast in situ in the printer head.
9. A printer head as claimed in Claim 1, wherein the printer head comprises a dielectric synthetic material.
10. A printer head as claimed in Claim 1 wherein each drive element comprises a ceramic tube.
11. A printer head as claimed in Claim 10, wherein the quotient of the wall thickness of the ceramic tube divided by its mean diameter is equal to the Poisson's ratio of the ceramic material.
12. A printer head as claimed in Claim 10 or Claim 11, wherein the ceramic tube has an external metal coating which serves as an electrode.
13. A printer head as claimed in Claim 10, wherein arranged inside the ceramic tube is an electrically conductive protective tube which serves as a further electrode.
14. A printer head as claimed in Claim 13, wherein the protective tube is affixed to the ceramic tube by means of an electrically conductive adhes-ive.
15. A printer head as claimed in Claim 14, wherein the adhesive impermeable to the printing ink used.
16. A printer head as claimed in Claim 7, whereln the diameter of said openings is 350µm.
17. A printer head as claimed in Claim 1, wherein the mesh size of the grid is 35µm.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19752543451 DE2543451C2 (en) | 1975-09-29 | 1975-09-29 | Piezoelectrically operated writing head for ink mosaic writing devices |
| DEP2543451.9 | 1975-09-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1093137A true CA1093137A (en) | 1981-01-06 |
Family
ID=5957767
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA256,830A Expired CA1093137A (en) | 1975-09-29 | 1976-07-13 | Piezoelectrically operated printer heads |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS6016350B2 (en) |
| CA (1) | CA1093137A (en) |
| DE (1) | DE2543451C2 (en) |
| FR (1) | FR2325509A1 (en) |
| GB (1) | GB1515777A (en) |
| IT (1) | IT1072793B (en) |
| NL (1) | NL178765B (en) |
| SE (1) | SE417693B (en) |
Families Citing this family (47)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2808275C2 (en) * | 1978-02-27 | 1983-03-10 | NCR Corp., 45479 Dayton, Ohio | Inkjet printhead |
| DE2808274C2 (en) * | 1978-02-27 | 1983-11-03 | NCR Corp., 45479 Dayton, Ohio | Ink jet recording head and method for making the same |
| JPS5511887A (en) * | 1978-07-14 | 1980-01-28 | Seiko Epson Corp | Ink jet recording device |
| JPS5582591U (en) * | 1978-12-04 | 1980-06-06 | ||
| US4317124A (en) | 1979-02-14 | 1982-02-23 | Canon Kabushiki Kaisha | Ink jet recording apparatus |
| DE3051102C2 (en) * | 1979-02-14 | 1995-07-27 | Canon Kk | Ink drop recording device for HF signals |
| US4334234A (en) * | 1979-04-02 | 1982-06-08 | Canon Kabushiki Kaisha | Liquid droplet forming apparatus |
| DE3051203C2 (en) * | 1979-04-02 | 1994-12-22 | Canon Kk | Ink jet recording head |
| JPS55146771A (en) * | 1979-05-02 | 1980-11-15 | Seiko Epson Corp | Ink-jet head and preparation thereof |
| DE2925812C2 (en) * | 1979-06-26 | 1982-10-21 | Siemens AG, 1000 Berlin und 8000 München | Ink printing device for multi-colored printing on a recording medium |
| JPS5615364A (en) * | 1979-07-18 | 1981-02-14 | Toshiba Corp | Ink jet recorder |
| DE2943018C3 (en) * | 1979-10-24 | 1982-05-13 | Siemens AG, 1000 Berlin und 8000 München | Method and arrangement for displaying a halftone image |
| DE2949616C2 (en) * | 1979-12-10 | 1982-12-16 | Siemens AG, 1000 Berlin und 8000 München | Writing head for ink mosaic writing devices |
| DE3006726C2 (en) * | 1980-02-22 | 1982-03-11 | Siemens AG, 1000 Berlin und 8000 München | Ink writing device |
| DE3018586C2 (en) * | 1980-05-14 | 1984-06-28 | Siemens AG, 1000 Berlin und 8000 München | Arrangement for the controllable dosage of the writing fluid in liquid writing devices |
| DE3019822A1 (en) * | 1980-05-23 | 1981-12-03 | Siemens AG, 1000 Berlin und 8000 München | ARRANGEMENT FOR A WRITING HEAD IN INK MOSAIC WRITING DEVICES |
| JPS5718265A (en) * | 1980-07-04 | 1982-01-30 | Canon Inc | Ink feeding device for ink jet recording device |
| JPS5725969A (en) * | 1980-07-22 | 1982-02-10 | Canon Inc | Liquid jet recorder |
| JPS5751475A (en) * | 1980-09-12 | 1982-03-26 | Seiko Epson Corp | Ink jet recording apparatus |
| DE3123689C2 (en) * | 1981-06-15 | 1987-01-08 | Siemens AG, 1000 Berlin und 8000 München | Device for ejecting ink droplets in ink writing devices as required |
| JPS582914A (en) * | 1981-06-27 | 1983-01-08 | Matsushita Electric Ind Co Ltd | Self-excited converter circuit |
| JPS58187367A (en) * | 1982-04-28 | 1983-11-01 | Nec Corp | Multi-nozzle printing head |
| IT1145242B (en) * | 1981-12-23 | 1986-11-05 | Olivetti & Co Spa | INK JET PRINT HEAD AND RELATED SERIAL PRINTER |
| US4449135A (en) * | 1981-12-23 | 1984-05-15 | Ricoh Company, Ltd. | Ink ejection head |
| DE3250105C2 (en) * | 1981-12-29 | 2001-02-22 | Canon Kk | Ink jet printer head |
| US4611219A (en) | 1981-12-29 | 1986-09-09 | Canon Kabushiki Kaisha | Liquid-jetting head |
| DE3204662C2 (en) * | 1982-02-10 | 1984-03-08 | Siemens AG, 1000 Berlin und 8000 München | Writing mechanism of an ink pen working according to the vacuum process |
| US4540996A (en) * | 1982-05-11 | 1985-09-10 | Canon Kabushiki Kaisha | Recording apparatus |
| JPS5942964A (en) * | 1982-09-03 | 1984-03-09 | Fujitsu Ltd | Drop-on-demand type rpint head |
| DE3234394C2 (en) * | 1982-09-16 | 1986-12-18 | Siemens AG, 1000 Berlin und 8000 München | Piezoelectric droplet ejector for ink mosaic pens |
| DE3234408C2 (en) * | 1982-09-16 | 1986-01-09 | Siemens AG, 1000 Berlin und 8000 München | Write head with piezoelectric drive elements for ink writing devices |
| DE3238732A1 (en) * | 1982-10-19 | 1984-04-19 | Siemens AG, 1000 Berlin und 8000 München | Gas bubble trap |
| DE3313156A1 (en) * | 1983-04-12 | 1984-10-18 | Nixdorf Computer Ag, 4790 Paderborn | PIEZOELECTRICALLY OPERATED WRITING HEAD FOR INK MOSAIC WRITING DEVICES |
| DE3324043A1 (en) * | 1983-07-04 | 1985-01-17 | Siemens AG, 1000 Berlin und 8000 München | Piezo-electric drive element for ink mosaic printer |
| DE3341399A1 (en) * | 1983-11-15 | 1985-05-23 | Siemens AG, 1000 Berlin und 8000 München | METHOD FOR INCREASING RESOLUTION IN AN INK MOSAIC WRITING DEVICE AND ARRANGEMENT FOR IMPLEMENTING THE METHOD |
| JPS59140068A (en) * | 1984-01-09 | 1984-08-11 | Seiko Epson Corp | Method for filling up ink into ink jet recorder |
| DE3401071A1 (en) * | 1984-01-13 | 1985-07-25 | Siemens AG, 1000 Berlin und 8000 München | Device for refilling ink containers in inking apparatuses |
| DE3418201A1 (en) * | 1984-05-16 | 1985-11-21 | Siemens AG, 1000 Berlin und 8000 München | Device for positioning insert needles in a cavity of a casting mould or injection mould |
| JPS6147641U (en) * | 1984-08-31 | 1986-03-31 | 三洋電機株式会社 | inkjet head |
| DE3438033A1 (en) * | 1984-10-17 | 1986-04-24 | Siemens AG, 1000 Berlin und 8000 München | Printhead for ink printers |
| DE3607992A1 (en) * | 1985-04-08 | 1986-10-09 | VEB Kombinat Robotron, DDR 8010 Dresden | Ink jet print head with a damping device dependent on the viscosity of the ink |
| DE3630206A1 (en) * | 1985-09-06 | 1987-03-19 | Fuji Electric Co Ltd | INK JET PRINT HEAD |
| DE3729206A1 (en) * | 1987-08-28 | 1989-03-09 | Siemens Ag | METHOD FOR FORMING INK CHANNELS IN A WRITING HEAD FOR AN INK MOSAIC WRITING DEVICE |
| DE3729205A1 (en) * | 1987-08-28 | 1989-03-09 | Siemens Ag | METHOD FOR FORMING INK CHANNELS IN A WRITING HEAD FOR AN INK MOSAIC WRITING DEVICE |
| JPH0664165A (en) * | 1992-06-09 | 1994-03-08 | Sharp Corp | Recording head for ink jet printer |
| DE69506306T2 (en) | 1994-04-20 | 1999-06-10 | Seiko Epson Corp., Tokio/Tokyo | Ink jet recording apparatus and method for manufacturing an ink jet head |
| EP1080915B1 (en) | 1999-09-03 | 2011-07-20 | Canon Kabushiki Kaisha | Liquid ejecting head unit |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3298030A (en) * | 1965-07-12 | 1967-01-10 | Clevite Corp | Electrically operated character printer |
| DE1611431C3 (en) * | 1967-11-10 | 1975-08-14 | Johann 8100 Garmisch- Partenkirchen Distl | Wire print head |
| US3946398A (en) * | 1970-06-29 | 1976-03-23 | Silonics, Inc. | Method and apparatus for recording with writing fluids and drop projection means therefor |
| US3683212A (en) * | 1970-09-09 | 1972-08-08 | Clevite Corp | Pulsed droplet ejecting system |
| BE790064A (en) * | 1971-10-14 | 1973-02-01 | Mead Corp | DROP GENERATOR FOR RECORDING DEVICE. |
| IT971258B (en) * | 1971-12-23 | 1974-04-30 | Ibm | CARTRIDGE CONTAINER FOR LICUID BLACK COUNTERS IN PARTICULAR INK |
| DE2324610C2 (en) * | 1973-05-16 | 1975-03-06 | Olympia Werke Ag, 2940 Wilhelmshaven | Write head for generating a fine-screened character from drops of writing liquid on a recording medium |
-
1975
- 1975-09-29 DE DE19752543451 patent/DE2543451C2/en not_active Expired
-
1976
- 1976-03-25 SE SE7603628A patent/SE417693B/en not_active IP Right Cessation
- 1976-06-23 GB GB2606876A patent/GB1515777A/en not_active Expired
- 1976-07-13 CA CA256,830A patent/CA1093137A/en not_active Expired
- 1976-09-09 FR FR7627188A patent/FR2325509A1/en active Granted
- 1976-09-22 NL NL7610532A patent/NL178765B/en not_active IP Right Cessation
- 1976-09-24 IT IT2759076A patent/IT1072793B/en active
- 1976-09-29 JP JP11707476A patent/JPS6016350B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2543451C2 (en) | 1982-05-06 |
| FR2325509A1 (en) | 1977-04-22 |
| SE417693B (en) | 1981-04-06 |
| JPS6016350B2 (en) | 1985-04-25 |
| DE2543451A1 (en) | 1977-03-31 |
| NL7610532A (en) | 1977-03-31 |
| FR2325509B1 (en) | 1983-04-08 |
| NL178765B (en) | 1985-12-16 |
| JPS5249033A (en) | 1977-04-19 |
| IT1072793B (en) | 1985-04-10 |
| GB1515777A (en) | 1978-06-28 |
| SE7603628L (en) | 1977-03-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |