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Publication numberUS3900162 A
Publication typeGrant
Publication dateAug 19, 1975
Filing dateJan 10, 1974
Priority dateJan 10, 1974
Also published asCA1015022A1, DE2455854A1, DE2455854B2
Publication numberUS 3900162 A, US 3900162A, US-A-3900162, US3900162 A, US3900162A
InventorsTitus Donald E, Tsao Sherman H M
Original AssigneeIbm
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method and apparatus for generation of multiple uniform fluid filaments
US 3900162 A
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Description  (OCR text may contain errors)

United States Patent Titus et al.

1 51 Aug. 19, 1975 METHOD AND APPARATUS FOR GENERATION OF MULTIPLE UNIFORM FLUID FILAMENTS Assistant Examiner.lohn J. Love [75] Inventors: g 'la T g l lg g tfi Attorney, Agent, or FirmKenneth P. Johnson sao, pa ac 1n, 0 57 ABSTRACT [73] Assignee: International Business Machines Meth d nd apparatus for generating a plurality of Corporation, Armonk, parallel droplet streams in a coating apparatus, such as [22] Filed: Jam 10 1974 an ink jet printing device, in which the streams break into droplets from fluid filaments at a uniform dis- PP NOJ 432,260 tance from issuing orifices. The streams issue from a pressurized chamber in which an elastic bending mem- [52] Us. CL 239/102, 239/566, 346/75 ber is repetitively flexed by a plurality of parallel [51] Int. Cl BtiSb 1/08 bending elements Operated Simultaneously to produce [58] Field 102 3 l5 uniform bending throughout the effective length of 2, said member to produce successive pressure disturbances within the supply chamber and induce varicosi- [56] References Cited ties of the same size and frequency in the issuing streams. This arrangement is able to enhance printing UNITED S'liATES PATENTS quality in an ink jet recorder by permitting mainte- 3,211,088 10/1965 Naiman 239/102 X name f proper phase relationship between droplet iwzet ett 2:1. formation and charging voltage e e e a 3,700,169 10/1972 Naydan 239/4 14 Claims, 8 Drawing Figures 1e 1 m 4i 54 40 1 V 1 z 12 1 C 59% Q; I, so i r 51 Q PATENTEUAUG-l ems 3.900.162

sum 1 UF 2 METHOD AND APPARATUS FOR GENERATION OF MULTIPLE UNIFORM FLUID FILAMENTS BACKGROUND OF THE INVENTION This invention relates generally to fluid droplet generation and more particularly to the generation of parallel fluid droplet streams in which the streams change from filaments to droplets at the same distance from the issuing orifices.

In the construction of ink jet recorders having a plurality of parallel recording streams of uniform velocities that are to each pass in charging relationship with a charging electrode, there is difficulty encountered in attempting to maintain the integrity of each stream as a filament to the same distance from the issuing orifice so that the streams break into droplets at the same point and time. The droplets are selectively charged at the point of breakoff from the filament and subsequently deflected along a desired trajectory downstream by electrostatic deflection plates. Deflected droplets may be either recorded or discarded depending on the printing mode. When the transition point from filament to droplet changes, then the droplet does not form with the proper charge and hence is not deflected to the desired impact point. The unpredictability of the drop breakoff point is especially troublesome in multi-jet printheads where it is highly desirable that the printing or non-printing of the plurality of jets in a row operate in synchronism.

Usually a single ultrasonic transducer is used to produce pressure variations within ink supply chamber or manifold so that the difficulty is not with the synchronization of two or more transducers. When a single vibrating transducer is used to stimulate drop formation, however, acoustical waves of generally varying intensity are present at the issuing orifices. Thus, the filament lengths vary directly with the intensity of the stimulating pressure waves.

In the past. an attempt has been made to maintain uniform stimulating pressure waves throughout the length of a row of orifices by mounting the transducer at one end of the row of orifices so that the bending wave resulting from the vibrating transducer is propogated along the length of the plate. The ends of the plate are damped to inhibit vibrational reflections and maintain a relatively pure stimulation disturbance. With this technique, the filament lengths become more nearly uniform but there still remains a difference between the length of filaments nearest the transducer and those farthest away. The more remote filaments tend to be longer in length resulting in delayed drop formation and irregular charging.

It is accordingly a general object of this invention to provide an ink jet recorder of improved reliability and quality.

Another important object of this invention is to provide an ink jet recorder in which the lengths of parallel filaments issuing from jet orifices are more nearly uniform so that droplets form at each filament at approximately the same time and same distance from the orifices.

A still further object of this invention is to provide an ink jet manifold with a vibrational transducer arranged therein such that in operation uniform stimulating pressure changes are transmitted simultaneously to all issuing orifices.

LII

Another object of this invention is to provide an ink jet manifold for issuing plurality of parallel fluid filaments having varicosities induced therein by a vibrating member in the supply chamber which is operated in conjunction with a specially shaped chamber to increase the effective amplitude of the generated acoustic waves.

SUMMARY OF THE INVENTION The foregoing objects are attained in accordance with the principles of the invention by providing within a pressurized ink supply manifold having a linear array of stream-issuing orifices, a flexible elastic bending member which is freely permitted to bend about a single axis. A plurality of piezoelectric transducers are secured in a common orientation to one side of the bending member and all transducers are energized simultaneously from a common potential source to produce simultaneous bending of the member along its length. The member is preferably coextensive with the length of the manifold and parallel to the linear array of orifices through which pressurized ink is forced in parallel streams. The bending member has a spaced pair of slits cut therein to provide a free boundary for the bending member and permit more uniform movement of the bending portion. In the preferred embodiment, the bending member separates the manifold cavity into two compartments, each specially formed to concentrate pressure waves created by the bending member at the two converging extremities of the compartments.

The invention has the advantage of being capable of producing a bending wave of uniform intensity along its length and along a linear array of nozzles when the bending member is parallel therewith. Thus, the fluid issuing from the orifices can be subjected to a series of pressure waves of uniform amplitude so that nearly identical varicosities are induced in each stream at the same time. Because of this, the phase relationship between charging voltages for the several streams and the drop formation is easier to maintain. This results in improved printing quality since better registration of droplet impact is possible.

The foregoing and other objects, features and advan tages of the invention will be apparent from the following more particular description of preferred embodiments of the invention as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded view of a marking head constructed in accordance with the principles of the invention.

FIG. 2 is a perspective view of the marking head of FIG. 1 when assembled.

FIG. 3 is a sectional elevation view of the marking head taken along the lines 33 in FIG. 2.

FIGS. 4a and 4b are rear elevation and plan views, respectively, of the vibrational bending member shown in FIGS. I and 3.

FIGS. 5a and 5b are schematic diagrams comparing streams issuing from a conventional marking head and one which incorporates the invention.

FIG. 6 is a front elevation view of an alternative embodiment of the bending member shown in FIGS. 40 and 4b.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1, 2 and 3, a marking head constructed in accordance with the invention comprises generally a rear cavity block 10, a vibrational bending member 11, a front cavity block 12, an orifice plate 13. an insulative element 14, and a charging plate 35. Block is formed with a rear converging cavity while cavity 16 in block 12 is forwardly converging. When the two cavity blocks are secured together about member 11, there is formed a substantially diamondshaped chamber which serves as a manifold for plurality of marking fluid orifices. Cavity 16 extends through block 12 and forms a slot 17 in the front surface 18 of the block. Intermediate blocks 10 and 12 is a vibratory bending member 11 of a thin, flexible, elastic material such as stainless steel having a thickness of approximately 5 mils. The depth of each cavity 15 and 16 is preferably one quarter of the wave length of the operating frequency of bending member 11. This depth produces a standing wave at each cavity extremity.

Bending member 11 is shown in greater detail in FIGS. 4a and 4b. The bending member is generally rectangular and of sufficient size to be secured between blocks 10 and 12 and divide the manifold cavity into the front and rear compartments l5 and 16. The member comprises generally a shaded marginal portion 20 which is gripped between the cavity blocks, and a similarly secured tab portion 21 of sufficient length to extend beyond the outside edges of blocks 10 and 12 when assembled together. A central vibratory portion 22 of the bending member is cut free of the member proper by two slits 23 extending through the thickness of the member. This permits the vibratory center portion 22 to be free at its ends.

On one side of bending member 11 between slits 23 is placed a plurality of transducers, preferably piezoelectric strips of a material such as barium titanate. These strips are cut with a length to width ratio varying from approximately 4:l to 6:1 and have a thickness of approximately 10 mils. The length of the transducer strips 24 is preferably approximately the length of the slits 23 which can in turn vary according to the amount of bending deflection desired within cavity compartments l5 and 16. The piezoelectric material is preferably selected for maximum bending. As is shown in FIG. 3, transducer strips 24 extend beyond the upper and lower limits of compartments l5 and 16 but may be shortened to less than the edges of the compartments proper adjacent bending member 11. The relatively large length to width ratio is desirable for the piezoelectric strips in order to maximize bending of central portion 22 about its longitudinal axis. The piezoelectric material is mounted for expansion in the thickness mode only and when energized will tend to bend in a dish-shaped manner. The narrow width of each transducer finger tends to minimize the effect of the dishing and thus produce single axis bending.

Transducer strips 24 are secured to central portion 22 of bending member 11 by an adhesive such as a bonding epoxy. The number and spacing of the transducer fingers 24 will be determined, as mentioned above,by the required deflection of central portion 22 to effect the necessary pressure waves within the issuing fluid. Transducer fingers 24 are mounted with the same orientation, of course, so that all transducers when energized will effect a bending force inunison on central portion 22. The transducers should be evenly spaced and parallel to relief slots 23. After the transducer fingers have been mounted to element 11, the voids between the fingers are filled with a suitable adhesive such as epoxy. Thereafter, each of the fingers is electrically connected via a conductor 25 soldered to the exposed outside surface of each of the fingers and to a terminal block 26. The terminal block is secured with a suitable insulative adhesive to bending member 11. At terminal block 26, an insulated conductor 27 is connected with the wire 25 and secured with an adhesive along tab 21. Thereafter, transducers 24 and wire 25 are coated with an insulative protective material which serves also as a moisture seal. A polyurethane or other suitable material may be used.

Bending member 11 with transducer fingers 24 thereon is mounted between cavity blocks 10 and 12 using a pair of gaskets 30 as shown in FIGS. 1 and 3. A recess 31 is preferably provided in one of the cavity blocks such as block 10 to allow tab portion 21 of bending member 11 and conductor 27 to extend below the lower surface of the block for attachment to suitable electrical signal generating source 28, such as a sinewave generator. By using a conductive bending element and adhesive for mounting fin gers 24, the energizing circuit issimplified. Blocks 10 and 12 are preferably secured together with screws placed so as to prevent leakage of a pressurized fluid within the cavity. Orifice plate 13 is secured to the rear surface of insulative element 14 with an adhesive and both are then secured to front surface 18 of cavity block 12 with suitable means such as screws (not shown). A gasket 31 is used to provide a seal. Thereafter, insulative plate element 14 with openings 34 aligned with orifices 33 is secured to orifice plate 13. The insulative element 14 is used to allow subsequent attachment of charging plate 35 containing charge rings 36 with which fluid droplets can be selectively charged as they break off from filaments extending from orifices 33. Orifices may range in size from 0.5 to L5 mils in diameter whileholes 34 are larger, such as 6 to 8 mils. 1

After the marking head has been assembled, it is connected to a suitable pressurized ink supply as indicated by pump 37 and duct 38 which are connected with inlet opening 38 that communicates along a groove with cavities 15 and 16 as shown in FIG. 3. Vents 43 with stoppers 44 permit bleeding off of air during charging. Since the two cavities are interconnected by slits in bending member 22, the manifold is equally pressurized in both compartments providing balanced static pressures. Tab portion 21 of bending member 11 and the conductor 27 extending beyond the bottom of the marking head are connected across the signal source sinewave generator 28, that is capable of applying an actuating signal, for example, from to Khz, to piezoelectric transducer fingers 24.

As pressurized ink is forced from the linear array of orifices 33, the pulses applied to piezoelectric transducers 24 cause central portion 22 of the bending element to deflect to a position such as shown by dotted line 40 in FIG. 3. The signal generator may operate between ground and some voltage or be connected so as to operate as voltage swings about the ground level. If the latter condition is used then, of .course. bending member deflection will be between the pair of dotted. lines 40 and 41. The energization of transducers 24, by

causing central portion 22 to repetitively flex sets up pressure waves within converging compartments l5 and 16 causing the ink at each of the orifices to experience a change in pressure simultaneously along the orifice array. This causes the occurrence of varicosities in the fluid filament issuing from each orifice which results in the formation of droplets in each stream at the same distance from orifice plate 13.

Referring to FIGS. 5a and b, there'is illustrated for comparative purposes a schematic representation of droplets formed by prior art, vibratory devices and those formed with structure assembled in accordance with the invention. It will be noted that fluid streams 50 issuing from the orifice plate, FIG. 5a as in the prior art tend to break up at a varying distance from the orifice plate within the charge plate. The breakup for the filaments into droplets occurs usually in a pattern which is reflective of the variations in wave intensity at the orifice plate and along the orifice array direction. When the vibratory element 11 as disclosed above is used within the ink manifold, each fluid filament 51 has induced therein at the same time and with the same magnitude a pressure variation which results in similar varicosities occurring along each filament as it issues from the orifice. This has the advantage of resulting in droplet breakoff at the same point and time within the charge plate. By using the latter structure, much of the difficulty in maintaining the proper phase relationship in both time and space between corresponding drops of the array of filaments is obviated with the result that droplets are more accurately registered on a recording surface.

In FIG. 6 there is shown a modification of bending element 11 in which stiffening bars 45 are added transversely of transducer fingers 24 and on the opposite side of central flexing portion 22. The stiffening bars are optional and used only if portion 22 tends to bend transversely of the desired bending. Bars 45 may be adhesively secured to element 11. Also, the bars may be replaced with a corrugated shim stock to accomplish the same result. The preferred material is stainless steel in either case so as to prevent corrosion. Other metals, however, may be used if desired.

Although bending element 11 has been shown secured on all edges about the flexing portion 22, it can be secured only along opposite edges or along a single edge, preferably an edge parallel to the bending axis.

While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. Apparatus for producing a plurality of parallel streams of fluid droplets comprising:

means providing a cavity for receiving pressurized nozzle means along a wall of said cavity means having at least one row of orifices therein;

means for supplying fluid under pressure to said cavity so that said fluid flows through said orifices in parallel streams;

means within said cavity for generating a series of pressure distrubances therein, said generating means including a flexible member and a plurality of independently movable elements cooperably bending said member to produce a said pressure disturbance when moved; and

means for simultaneously and repetitively moving said elements to create a said pressure disturbance along said nozzle row, thereby creating pressure perturbations within said issuing streams.

2. Apparatus as described in claim 1 wherein said elements are aligned on said flexible member in a row parallel to said orifices.

3. Apparatus as described in claim 2 wherein said member is a planar member secured along an edge thereof in said cavity forming means.

4. Apparatus as described in claim 3 wherein said elements are parallel piezoelectric strips commonly secured on said planar member.

5. Apparatus as described in claim 1 wherein said planar member is fixed along its periphery in said cavity forming means with a major surface thereof parallel to said nozzle row, and said elements are piezoelectric strips commonly secured to the opposite major surface of said member in a row extending parallel with said nozzle row.

6. Apparatus as described in claim 3 wherein said member is fixed at its periphery in said cavity forming means so as to divide said cavity into first and second compartments, and said member includes at least two openings therein to interconnect said two compartments.

7. Apparatus as described in claim 6 wherein said opposite walls of each compartment converge as a function of the distance from said flexible member.

8. Apparatus as described in claim 7 wherein said nozzle means is secured along a surface of one of said compartments opposite said planar member.

9. Apparatus as described in claim 4 wherein said planar member includes at least one stiffening component secured thereto on the surface opposite said elements and is oriented in a direction transverse to the longitudinal axis of said elements.

10. Apparatus as described in claim 7 wherein said compartment walls converge at a point approximately equal to one quarter of the wave length of the operating frequency of said elements.

11. Apparatus for producing a plurality of parallel streams of fluid droplets comprising:

means for providing a cavity for receiving pressurized fluid therein;

nozzle means along a wall of said cavity means having a row of orifices therein for issuing parallel streams of fluid;

means for supplying pressurized fluid to said cavity to produce said streams;

means within said cavity for generating a series of pressure disturbances therein, said generating means including a flexible member bendable about an axis parallel with the longitudinal axis of said orifice row; and

bending means energizable to bend said member about said axis.

12. Apparatus according to claim 11 wherein said bending means comprises piezoelectric material.

13. Apparatus according to claim 11 wherein said flexible member is secured along its periphery and has a pair of slits therein normal to said bending axis.

14. Apparatus according to claim 11 further including means for energizing said bending means to create a pressure disturbance along said row.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3211088 *May 4, 1962Oct 12, 1965Sperry Rand CorpExponential horn printer
US3373437 *Aug 1, 1967Mar 12, 1968Raymond C. CummingFluid droplet recorder with a plurality of jets
US3679132 *Jan 21, 1970Jul 25, 1972Cotton IncJet stream vibratory atomizing device
US3700169 *Oct 20, 1970Oct 24, 1972Environment One CorpProcess and appratus for the production of hydroelectric pulsed liquids jets
US3747120 *Jan 10, 1972Jul 17, 1973N StemmeArrangement of writing mechanisms for writing on paper with a coloredliquid
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4005435 *May 15, 1975Jan 25, 1977Burroughs CorporationLiquid jet droplet generator
US4007465 *Nov 17, 1975Feb 8, 1977International Business Machines CorporationSystem for self-cleaning ink jet head
US4015272 *Aug 7, 1975Mar 29, 1977Matsushita Electric Industrial Co., Ltd.Ink ejection type writing unit
US4032928 *Aug 12, 1976Jun 28, 1977Recognition Equipment IncorporatedWideband ink jet modulator
US4065774 *May 30, 1975Dec 27, 1977International Business Machines CorporationHybrid fluid jet drop generation
US4095232 *Jul 18, 1977Jun 13, 1978The Mead CorporationApparatus for producing multiple uniform fluid filaments and drops
US4188635 *Oct 3, 1977Feb 12, 1980International Business Machines CorporationInk jet printing head
US4245225 *Nov 8, 1978Jan 13, 1981International Business Machines CorporationInk jet head
US4282532 *Jun 4, 1979Aug 4, 1981Xerox CorporationInk jet method and apparatus using a thin film piezoelectric excitor for drop generation
US4290074 *Nov 21, 1979Sep 15, 1981Compagnie Internationale Pour L'informatique Cii-Honeywell Bull (Societe Anonyme)Ink drop generator for ink jet printer
US4296417 *Jun 4, 1979Oct 20, 1981Xerox CorporationInk jet method and apparatus using a thin film piezoelectric excitor for drop generation with spherical and cylindrical fluid chambers
US4303927 *Mar 23, 1977Dec 1, 1981International Business Machines CorporationApparatus for exciting an array of ink jet nozzles and method of forming
US4326553 *Aug 28, 1980Apr 27, 1982Rca CorporationMegasonic jet cleaner apparatus
US4370662 *Dec 2, 1980Jan 25, 1983Ricoh Company, Ltd.Ink jet array ultrasonic simulation
US4383264 *Jun 18, 1980May 10, 1983Exxon Research And Engineering Co.Demand drop forming device with interacting transducer and orifice combination
US4465234 *Oct 5, 1981Aug 14, 1984Matsushita Electric Industrial Co., Ltd.Liquid atomizer including vibrator
US4530464 *Jul 11, 1983Jul 23, 1985Matsushita Electric Industrial Co., Ltd.Ultrasonic liquid ejecting unit and method for making same
US4596990 *Jul 2, 1984Jun 24, 1986Tmc CompanyMulti-jet single head ink jet printer
US4646106 *Feb 3, 1984Feb 24, 1987Exxon Printing Systems, Inc.Method of operating an ink jet
US4667877 *Aug 15, 1985May 26, 1987Carnegie-Mellon UniversityMulti-orifice impulsed spray generator
US4702418 *Sep 9, 1985Oct 27, 1987Piezo Electric Products, Inc.Aerosol dispenser
US6039059 *Sep 30, 1996Mar 21, 2000Verteq, Inc.Wafer cleaning system
US6050679 *Feb 13, 1996Apr 18, 2000Hitachi Koki Imaging Solutions, Inc.Ink jet printer transducer array with stacked or single flat plate element
US6116517 *Jun 24, 1997Sep 12, 2000Joachim HeinzlDroplet mist generator
US6132035 *Apr 21, 1994Oct 17, 2000Fujitsu LimitedPrinting head having resiliently supported vibration plate
US6135357 *Nov 23, 1998Oct 24, 2000General Electric CompanyApparatus for atomizing high-viscosity fluids
US6140744 *Apr 8, 1998Oct 31, 2000Verteq, Inc.Wafer cleaning system
US6295999Aug 22, 2000Oct 2, 2001Verteq, Inc.Vibrating rod-like probe close to flat surface to loosen particles; agitating with megasonic energy to clean semiconductors
US6463938Sep 13, 2001Oct 15, 2002Verteq, Inc.Wafer cleaning method
US6681782Sep 12, 2002Jan 27, 2004Verteq, Inc.Housing end wall through which the vibrational energy is transmitted is thinner than the heat transfer member positioned between the probe and the transducer
US6684891Sep 12, 2002Feb 3, 2004Verteq, Inc.Applying cleaning fluid to the wafer, positioning a vibration transmitter adjacent the wafer with a transducer coupled to the transmitter, energizing transducer to vibrate transmitter to transmit vibration into fluid to loosen particles
US7063141 *Jan 13, 2004Jun 20, 2006Halliburton Energy Services, Inc.Apparatus for agitated fluid discharge
US7117876Dec 3, 2003Oct 10, 2006Akrion Technologies, Inc.Method of cleaning a side of a thin flat substrate by applying sonic energy to the opposite side of the substrate
US7211932Mar 22, 2006May 1, 2007Akrion Technologies, Inc.Apparatus for megasonic processing of an article
US7240855 *Apr 19, 2004Jul 10, 2007Seiko Epson CorporationLiquid dispense head and manufacturing method thereof
US7268469Mar 15, 2006Sep 11, 2007Akrion Technologies, Inc.Transducer assembly for megasonic processing of an article and apparatus utilizing the same
US7514048 *Aug 22, 2002Apr 7, 2009Industrial Technology Research InstituteControlled odor generator
US7518288Aug 16, 2007Apr 14, 2009Akrion Technologies, Inc.System for megasonic processing of an article
US8257505Oct 11, 2011Sep 4, 2012Akrion Systems, LlcMethod for megasonic processing of an article
US8771427Sep 4, 2012Jul 8, 2014Akrion Systems, LlcMethod of manufacturing integrated circuit devices
US20090314853 *Jun 3, 2009Dec 24, 2009Ep Systems Sa Microflow DivisionVolatile liquid droplet dispenser device
US20110036921 *Jun 23, 2006Feb 17, 2011Microflow Enguineering SaVolatile liquid droplet dispenser device
Classifications
U.S. Classification239/102.2, 347/75, 239/566
International ClassificationB41J2/025, H04N1/032, H04N1/034, B41J2/015, B41J2/02
Cooperative ClassificationB41J2/025
European ClassificationB41J2/025