EP0611654A2 - Tintenstrahldruckkopf - Google Patents

Tintenstrahldruckkopf Download PDF

Info

Publication number
EP0611654A2
EP0611654A2 EP94101961A EP94101961A EP0611654A2 EP 0611654 A2 EP0611654 A2 EP 0611654A2 EP 94101961 A EP94101961 A EP 94101961A EP 94101961 A EP94101961 A EP 94101961A EP 0611654 A2 EP0611654 A2 EP 0611654A2
Authority
EP
European Patent Office
Prior art keywords
ink
print head
jet print
channels
coatings
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.)
Withdrawn
Application number
EP94101961A
Other languages
English (en)
French (fr)
Other versions
EP0611654A3 (de
Inventor
Wolfgang Dr. Wehl
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Eastman Kodak Co
Original Assignee
Eastman Kodak Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Eastman Kodak Co filed Critical Eastman Kodak Co
Publication of EP0611654A2 publication Critical patent/EP0611654A2/de
Publication of EP0611654A3 publication Critical patent/EP0611654A3/de
Withdrawn legal-status Critical Current

Links

Images

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
    • B41J2/16—Production of nozzles
    • B41J2/1606—Coating the nozzle area or the ink chamber

Definitions

  • the invention relates to an ink-jet print head having at least one row of adjacent ink channels each of which includes means which can be electrically activated separately and serve for ejecting ink drops from outlets opening associated with each of said channels in accordance with printing data.
  • ink-jet print heads which function according to the bubble-jet principle.
  • the electrically activatable element for ejecting ink drops is a heating element which is energized pulsewise.
  • the ink in the ink channel is heated locally so that an ink vapour bubble develops which collapses as soon as the power supply is cut.
  • This bubble causes a pressure wave in the ink channel, which allows an ink jet of a restricted mass to be ejected from the outlet opening onto the surface of a close record carrier.
  • the chemistry of the ink causes a number of problems.
  • the ink used must necessarily consist of a mixture of substances with evaporating capacities in order that the vapour bubble be produced on which the bubble-jet principle is based, and on the other hand the ink has to meet permanently all the requirements regarding color saturation, long-term stability, fastness properties, drying behaviour and resistance against wiping despite the fact that the ink is heated.
  • such ink material mainly consists of water which lends the ink properties which interfere with the requirements for resistance against wiping and fastness.
  • EP 0 278 590 relates to an electrically pulsed drop depositing device whose channel partition walls are tongue-shaped piezo elements fixed to one side of said walls. When two piezo elements which limit an ink channel are electrically activated, their free ends shift towards each other in a transverse direction and thus produce in the ink channel concerned the pressure wave required.
  • WO 91/17891 discloses an ink-jet print head of the bubble-jet type which consists of one integral piece made of a silicon block by anisotropic etching.
  • ink-jet print heads of this type need a lot of energy, produce a progressively growing amount of crosstalk as their resolution increases, and a high mechanical and thermal load on the actuating elements. Besides, it is very complicated and unreliable to determine the readiness for use if sensors are used which are heating elements.
  • an ink-jet print head whose separating walls are designed as resilient carriers of the electrodes of a capacitor, said electrodes being applied in the form of an electrically conductive insulated coating.
  • the material which is electrically insulating towards the outside is either an insulator, a semiconductor with surface passivation or a conductor provided with an insulating layer.
  • the conductive coatings which are arranged in a channel are insulated from each other electrically and connected to output terminals of a pulse supplying device and to input terminals of a device for determining the readiness for use.
  • the coatings of a wall separating the channels are each short-circuited.
  • an electrostatic field develops which exerts tensile forces on the walls confining the ink channel and separating the individual channels so that said walls at least partially move towards each other. This movement causes excess pressure to be produced in the ink channel concerned, said pressure being relieved as soon as a predetermined amount of ink has been ejected.
  • an electrostatic field develops which exerts tensile forces on the walls confining and separating the ink channels so that said walls at least partially move away from each other. This movement causes a vacuum to be produced in the ink channel concerned, said vacuum leading to the ink channel concerned to be refilled promptly.
  • This ink-jet print head is thus particularly suitable for very high resolutions, especially resolutions exceeding 300 dpi.
  • the conductive coatings are used to control the readiness for use of the ink channel concerned.
  • the coatings on the walls which confine an ink channel and separate the individual channels serve as capacitor plates with a dielectric medium between them.
  • this dielectric medium is ink, and in the case of disturbances it is air.
  • the surface and the distance between associated capacitor plates are known in the case of a given ink-jet print head and so are the dielectricity constants of air and of the ink used. Readiness for use is determined by measuring the capacity of the capacitor thus formed.
  • Fig. 1 is a perspective view of an ink-jet print head.
  • Said head essentially consists of only two parts to be combined, namely of a chip 11 which includes the actuating elements, the electric lead wires and the contact points 9 for the electric connection as well as the outlet openings 10, and of an ink supply container 12 to which the chip is attached and joined.
  • the actuating elements not illustrated in this schematic diagram, namely the electric lead wires, the contact points 9 and the outlet openings 10 can be manufactured in a number of planar processing steps to form a single chip 11 preferably consisting of silicon.
  • the ink supply container 12 into which a medium such as a sponge 13 soaked with ink is inserted has a rectangular configuration.
  • outlet openings with filters 14 are provided in the form of two supply channels 15.
  • Said supply channels 15 extend parallel with each other in the longitudinal direction of the ink supply container 12 such that when a chip 11 has been mounted, they are in flow connection with the outlet openings 10 via ink channels 16.
  • the chip 11 is mounted on the ink supply container 12 in a simple manner by using mounting clamps 17 which are arranged on the longitudinal sides of the ink supply container 12 and serve as a mechanical connection and, via contact points 9, as an electrical contact.
  • the ink-jet print head 24 is provided with a cover plate 2 arranged between the 11 and the ink supply container 12.
  • Fig. 2 is a perspective view of such a cover plate 1 prior to its mounting on chip 11.
  • Cover plate 1 has elongate openings 2 which extend parallel with each other and which cover the marginal areas of the ink channels 16 in chip 11.
  • the ink channels 16 are sealed by a membrane 3 which comprises the outlet opening 10.
  • Cover plate 1 consists e.g. of glass, silicon or ceramics and is anodically bonded to chip 11.
  • cover plate 1 could also be made of a platic sheet adapted to be laminated onto the plate or to be self-adhesive. The latter embodiment which does not require any other technical means ensures in particular that the joint between chip 11 and the ink supply container 12 is leakproof.
  • Fig. 3 is a perspective separate view of the chip 11 of the ink-jet print head 24.
  • the ink channels 16 are separated from each other by walls 8 which are provided on both sides with a conductive coating 28, preferably a metal layer which is applied together with the leads to the contact points 9.
  • Fig. 4 shows sectional views along lines I-I and II-II of Fig. 1.
  • Fig. 4a is a sectional view of chip 11 along line I-I of Fig. 1 and shows in particular the geometric design of an ink channel 16 with parallel walls which terminate in inclined zones 30.
  • a thin layer seals the nozzle of the ink channel 16.
  • This layer is designed as a membrane 3 which is provided with outlet openings 10.
  • chip 11 comprises a cover plate 1 on its side facing the ink supply container 12.
  • Said cover plate 1 has openings 2 which are arranged at the points where the ink channels 16 and the supply channels 15 overlap.
  • the cross-sectional surface of the openings 2 may be as big as the section resulting from the overlapping of the ink channel 16 and the supply channel 15 concerned.
  • Fig. 4b shows a sectional view of an ink-jet print head along line II-II of Fig. 1.
  • the walls 8 which separate the channels and are coated on both sides with a conductive coating 28 are arranged between the individual trapezoidal ink channels 16.
  • Membrane 3 includes outlet openings 10 which are each associated with one of the ink channels 16. In the direction of the ink supply container 12 not illustrated, the ink channels 16 are limited by a cover plate 1.
  • Fig. 5 shows a chip 11 in which ink channels 16 are configured which are covered by a membrane 3.
  • the outlet openings 10 are arranged such that every ink channel 16 is associated with an outlet opening 10.
  • all outlet openings 10 are arranged in a row which extends transversely to the longitudinal extension of the ink channels 16.
  • the outlet openings 10 are preferably aligned in the middle of the ink channel 16 concerned.
  • the print dots recorded through directly adjacent ink channels 16 are offset because only every other ink channel 16 can be activated at a time. Due to this offsetting, the distance between adjacent print dots on the record carrier increases in an advantageous manner. This distance is required for recordings on overhead transparencies and corresponds to the draft mode .
  • the outlet openings 10 are alternately arranged in two parallel rows. This embodiment is illustrated in Fig. 6 which corresponds to Fig. 5 except for the arrangement of the outlet openings 10.
  • the two rows of outlet openings 10 are preferably aligned symmetrically with the center line of the ink channels 16.
  • Directly adjacent ink channels 16 are activated one after the other.
  • the outlet openings 10 which are positioned at the front in the direction of relative movement of the ink-jet print head 24, carry out the recording operation, and after a time interval which corresponds to the quotient of the distance between the parallel rows of outlet openings 10 and the speed at which the ink-jet print head 24 moves relative to the record carrier, those ink channels 16 are activated whose outlet openings 10 are arranged at the rear in the direction of movement.
  • print dots can be placed on points of intersection of an orthogonal grid at a high recording speed.
  • the ink-jet print head according to the invention can be operated with a bi-polar control voltage.
  • a positive voltage (+) to ground (0) is provided.
  • Fig. 7 shows a section of an ink-jet print head whose ink channels 16 are each associated with two control terminals.
  • the two coatings carry positive charges.
  • the coatings of ink channels 16/2, 16/4, 16/6, 16/7 and 16/9 are discharged.
  • the coatings of the ink channel 16/8 have different potentials.
  • Direct vacuum or excess pressure means that the pressure ratio is based on the difference in the potential of the coating associated with the ink channel concerned.
  • An indirect excess pressure or vacuum in an ink channel is caused by differences in the potential of coatings of adjacent ink channels. Half an excess pressure does not lead to drop ejection.
  • the capacity of the individual ink channels can be measured and it can thus be detected whether or not ink is still present in the ink channel concerned, i.e. whether or not the ink channel is ready for operation or whether or not air has intruded the ink channel because of obstructions, lack of ink or other disturbances.
  • the distance between the coatings of each channel amounts to about 15 ⁇ m.
  • a pulse voltage of about 250 V is required between the coatings of an ink channel.
  • the surface of the coating being about 0.6 x 10 ⁇ 6 m2
  • the two coatings of a channel filled with ink have a capacity of about 30 pF and require an energy supply of about 0.9 ⁇ J for ejecting an ink drop.
  • a comparable bubble-jet print head requires at least 30 ⁇ J per drop ejection.
  • the ink channels are formed, for example, in a known manner in that the plane 110 is anisotropically etched in silicon. Subsequently, the surface of the walls separating the individual channels is oxydized or nitrified. The coatings are produced by evaporization and galvanization. Finally, an insulating protective layer such as silicon oxyde or silicon nitrite is applied to the coatings.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Particle Formation And Scattering Control In Inkjet Printers (AREA)
EP94101961A 1993-02-13 1994-02-09 Tintenstrahldruckkopf. Withdrawn EP0611654A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19934304733 DE4304733A1 (de) 1993-02-13 1993-02-13 Tintendruckkopf
DE4304733 1993-02-13

Publications (2)

Publication Number Publication Date
EP0611654A2 true EP0611654A2 (de) 1994-08-24
EP0611654A3 EP0611654A3 (de) 1995-01-25

Family

ID=6480634

Family Applications (1)

Application Number Title Priority Date Filing Date
EP94101961A Withdrawn EP0611654A3 (de) 1993-02-13 1994-02-09 Tintenstrahldruckkopf.

Country Status (2)

Country Link
EP (1) EP0611654A3 (de)
DE (1) DE4304733A1 (de)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4520375A (en) * 1983-05-13 1985-05-28 Eaton Corporation Fluid jet ejector
WO1991017891A1 (de) * 1990-05-21 1991-11-28 Mannesmann Ag Tintenschreibkopf für eine nach dem thermalwandlerprinzip arbeitende flüssigkeitsstrahlaufzeichnungsvorrichtung und verfahren zu seiner herstellung
EP0513971A2 (de) * 1991-03-19 1992-11-19 Tokyo Electric Co., Ltd. Tintenstrahldruckkopf und sein Herstellungsverfahren
EP0516284A2 (de) * 1991-05-28 1992-12-02 Brother Kogyo Kabushiki Kaisha Gerät mit Tröpfchenstrahl

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4333083A (en) * 1980-12-23 1982-06-01 International Business Machines Corporation Electrostatic drop sensor with sensor diagnostics for ink jet printers

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4520375A (en) * 1983-05-13 1985-05-28 Eaton Corporation Fluid jet ejector
WO1991017891A1 (de) * 1990-05-21 1991-11-28 Mannesmann Ag Tintenschreibkopf für eine nach dem thermalwandlerprinzip arbeitende flüssigkeitsstrahlaufzeichnungsvorrichtung und verfahren zu seiner herstellung
EP0513971A2 (de) * 1991-03-19 1992-11-19 Tokyo Electric Co., Ltd. Tintenstrahldruckkopf und sein Herstellungsverfahren
EP0516284A2 (de) * 1991-05-28 1992-12-02 Brother Kogyo Kabushiki Kaisha Gerät mit Tröpfchenstrahl

Also Published As

Publication number Publication date
DE4304733A1 (de) 1994-08-25
EP0611654A3 (de) 1995-01-25

Similar Documents

Publication Publication Date Title
US4536097A (en) Piezoelectrically operated print head with channel matrix and method of manufacture
US4458256A (en) Ink jet recording apparatus
US5059989A (en) Thermal edge jet drop-on-demand ink jet print head
US4935752A (en) Thermal ink jet device with improved heating elements
CA1306899C (en) Droplet deposition apparatus
EP1023179B1 (de) Tropfendetektor für tintenstrahlgeräte
EP0210848A2 (de) Thermischer Tintenstrahl-Druckkopf
US4947193A (en) Thermal ink jet printhead with improved heating elements
JPS59138461A (ja) 液体噴射記録装置
KR19980070728A (ko) 방울 크기 변경을 위한 잉크 젯 프린트헤드
US6059393A (en) Driving method for an ink ejection device to enlarge print dot diameter
US4021818A (en) Liquid printing device
EP0658142B1 (de) Tintenstrahldruckkopf
EP0488806B1 (de) Tintenstrahldruckkopf mit Steuerschaltung dafür
AU684289B2 (en) Differential drive system for an ink jet printhead
EP0043286B1 (de) Verfahren zum Ausstossen von Tröpfchen aus einer Anordnung impulsgesteuerter Tröpfchenauswerfer
EP1317338B1 (de) Piezoelektrisches tintenstrahldruckmodul
EP0611654A2 (de) Tintenstrahldruckkopf
JPH0551462B2 (de)
EP0267567B1 (de) Mit Flüssigkeitstrahl aufzeichnendes System, Aufzeichnungskopf hierfür, Grundplatte für den Aufzeichnungskopf und mit dem Aufzeichnungskopf ausgestattetes Gerät
JPH07304168A (ja) インク噴射装置
EP0695639A2 (de) Herstellungsverfahren für eine längsseitige Betätigungseinrichtung für einen Tintenstrahlkopf
EP1322475B1 (de) Tröpfchenabgabegerät
US6119342A (en) Method of producing a record head for an electrostatic ink jet recorder
US5917522A (en) Shearing made ink ejecting apparatus with reliable ejection over a range of temperatures

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE FR GB

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE FR GB

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 19950628