CN100567003C - Imaging device - Google Patents

Abstract

Disclosed a kind of imaging device, it comprises: record head, and it comprises the nozzle of liquid droplets therefrom, is communicated with nozzle and is equipped with the pressure chamber of liquid and the pressure generation part that changes pressure chamber's volume; And drive the signal generator branch, and being used for producing the driving signal that comprises a plurality of driving pulses, this driving signal makes pressure generation part so operate, thereby ejects drop from nozzle.By driving resonant drive pulse that driving signal that the signal generator branch produces comprises that in single print cycle the natural vibration period that is used for utilizing pressure chamber makes first drop eject, being used under the situation of the natural vibration period that does not utilize pressure chamber, making disresonance driving pulse that second drop ejects and being used for to prevent the slight drive pulse that makes that ink droplet jet goes out.

Description

Imaging device

Technical field

The present invention relates generally to imaging device, and more specifically to prevent to be used for liquid droplets spray nozzle clogging and improve image taking speed.

Background technology

Can carry out high-speed record, can be under the situation of not carrying out special photographic fixing operation at the enterprising line item of common paper and can be generally used for nearest many purposes with the ink jet recording device that relatively low cost is realized.Use wherein to be formed with the ink liquid chamber and the record head of the nozzle of connection with it, ink jet recording device makes drops out from nozzles fly out by exerting pressure according to the ink of image information in the ink liquid chamber so that for example form image on paper or the film attached to recording medium.

Printing on the common paper under the situation of especially using this ink jet recording device, have following obviously problem, promptly the degradation problem of ink jet recording device aspect the dried characteristic of color reducibility, durability, light resistance, China ink, pinniform defective, bleeding and the duplex printing characteristic of image is obvious.In addition, be very difficult on common paper, carry out flying print and satisfy all these characteristics simultaneously.

Usually, the common ink that is used for inkjet printing comprises water as its key component, and comprises that colouring agent and being used to prevents for example glycerine of the wetting agent that stops up.Colouring agent is dyestuff or pigment.In general, thus dye ink because its good colour development and stability more through being usually used in color components.But for example light resistance and resistance to water (water proofing property) are poorer as those performances that colouring agent obtained than using pigment to use image fastness that dye ink obtains.Specifically, though use the ink jet recording sheet with ink absorbing layer can realize to a certain degree improvement, resistance to water is also unsatisfactory in the situation of using common paper.

Therefore, in these years, the paint ink that has adopted organic pigment or carbon black as colouring agent is used for common paper prints and to have been studied or put into practical application so that reduce the problem that dye ink occurs in the situation of using common paper.Different with dyestuff, pigment is water insoluble.Therefore, the common and dispersant of pigment, thus stably be dispersed in the water by peptizaiton, use as water-based ink.Therefore by using pigment, can improve light resistance and resistance to water.But be difficult to satisfy simultaneously light resistance and resistance to water and other image quality characteristic.Specifically, carry out under the situation of flying print in the employing common paper, be difficult to obtain high image quality, enough colour development and enough color reducibilities, and pinniform defective, bleeding, duplex printing characteristic and China ink are done (fixation) characteristic and can not be allowed the people very satisfied.

For example, Japan special permission publication application No.6-171072 (JP6-171072) and No.2000-355159 (JP2000-355159) have disclosed the recording method that is used for solving in the problem of the situation of using this paint ink to print on common paper.According at the ink jet recording method disclosed in the JP6-171072, adopted the ink that comprises pigment, polymeric dispersant and resin emulsion.To when printing, high load capacity be controlled in the proper range by solid constituent adhesion amount of unit are on recording paper, thereby irrespectively alleviated the printing inhomogeneities that causes owing to the pigment cohesion with paper type, obtained not have the video high density quality of pinniform defective thus.In addition,, adopted the ink composition that comprises pigment and bleeding agent according at the ink jet recording method disclosed in the JP2000-355159, wherein pigment for have in its surface disperse group through surface treated pigments so that self can disperse in aqueous solvent.Control ink composition per unit area is ejected into the amount on the recording medium side so that prevent to produce the irregular bleeding of print image, and makes the ink composition that ejects dry rapidly on recording medium, obtains to have the print image of high print density thus.

According in the recording method disclosed in the JP6-171072, for example the contact angle of common paper is high with respect to the specification paper for the ink that is adopted, and for example more than or equal to 70 °, thereby has realized improving the print density that for example improves and has reduced the pinniform defective.But, with high load capacity under situation about printing on the recording paper, need per unit area to adhere to tens ng/m ²Solid matter, therefore causing problem aspect ink fixation (drying) characteristic.Specifically, carrying out with many stacked paper under the situation of flying print, owing to the paper pollution problem appears in the ink transfer between each paper.Therefore, this recording method is not suitable for flying print.In addition, also have such problem, wherein according to paper type since the high contact angle when 100% load is printed cause informal voucher partly occurring at solid section or character in the paper background.In addition, adjacent printed dots keeps drop because of high contact angle, thereby the bleeding problem appears in the boundary portion office between color easily.

On the other hand, in the recording method of the use bleeding agent disclosed in the JP2000-355159 because black dryness (fixation) and in excellence aspect the picture quality.Owing in the situation of carrying out flying print with many stacked paper, do not have to produce the paper pollution problem that causes owing to the ink transfer between paper, so this recording method is applicable to flying print.But, owing in ink composition, adopted bleeding agent, thus with the same pinniform defective that when the employing common paper prints, occurs in the dye ink situation.Especially in the situation of common paper, ink also permeates along the paper depth direction, thereby the ink puncture occurred, therefore makes it to be difficult to carry out duplex printing.Therefore, any method of obtaining in the recording method of high quality graphic of being used for disclosed in JP6-171072 and the JP2000-355159 is adopting common paper to carry out all can not making us satisfied fully aspect all above-mentioned characteristics in the flying print.

Effectively.Adopt high-viscosity ink so that by solving using paint ink to carry out caused problem in the common paper printing on common paper, to form high quality graphic at a high speed.But, in the situation that adopts high-viscosity ink, ink dried to its viscosity in all nozzles in nonprinting region and those spray nozzle clogging in the print area that does not print operation when higher around the meniscus of nozzle, thereby extremely reduce picture quality.In addition, even under the situation that nozzle does not have to stop up, can not obtain stable droplet ejection characteristics (drop speeds, droplet volume and along the bending of ink droplet jet direction), thereby can reduce picture quality.In order to prevent these problems, in a print cycle, produce a plurality of ejection drive pulse and a plurality of non-ejection drive pulse at the ink jet recording device disclosed in the Japan special permission publication application No.2005-41039 (JP2005-41039).Ejection drive pulse is exported so that eject drop according to sequential.Non-ejection drive pulse provides the meniscus with vibration, can not eject ink droplet thereby this vibration is very little.Each non-ejection drive pulse comprise be used for making first signal that expands with the nozzle pressure chambers communicating, the secondary signal of the swelling state of the chamber that first signal after, is used for keep-uping pressure and the 3rd signal that after the 3rd, is used for making pressure chamber's contraction.In addition, with respect to ejection drive pulse, the interval between the driving pulse of driving pulse and front thereof (pulse spacing) is three to five times of natural frequency of pressure chamber.

The secondary signal and being used for the 3rd signal after of swelling state of chamber of being used for keep-uping pressure equally be used for making first signal that expands with the nozzle pressure chambers communicating, first signal shown in JP2005-41039 after makes the 3rd signal of pressure chamber's contraction be used as non-injection pulse when being included in the print cycle, thereby the increase of the signal length of non-injection pulse has prevented the print speed increase.

In addition, if be three to five times of natural frequency of pressure chamber according to pulse spacing of a plurality of ejection drive pulse of sequential output in a print cycle, then a print cycle is that drive signal length increases, thereby has reduced print speed.

Summary of the invention

Embodiment of the present invention solve or have reduced one or more in the problems referred to above.

According to one embodiment of the invention, provide and wherein solved the one or more imaging device in the problems referred to above.

According to one embodiment of the invention, provide a kind of like this imaging device, even wherein under the situation of having used high-viscosity ink, also prevented all nozzles in nonprinting region and in print area, do not printed those nozzles of operation by the ink obstruction of drying around nozzle meniscus; In a print cycle, adopted and be used for to cause that providing the slight pulsed drive of vibration to meniscus under the situation that drop sprays changes the physical characteristic of ink and the liquid spray characteristic is caused negative effect so that prevent drying; And realized higher print speed.

According to one embodiment of the invention, a kind of imaging device is provided, it comprises: record head, it comprises the nozzle of liquid droplets therefrom, is communicated with nozzle and is equipped with the pressure chamber of liquid and the pressure generation part that changes pressure chamber's volume; And driving signal generator branch, be configured to produce the driving signal that comprises a plurality of driving pulses, this driving signal makes the pressure generation part of record head so operate, thereby from nozzle, eject drop, wherein comprise that by driving driving signal that the signal generator branch produces the natural vibration period that is used for utilizing pressure chamber makes the resonant drive pulse that first drop ejects in single print cycle, be used under the situation of the natural vibration period that does not utilize pressure chamber, making disresonance driving pulse that second drop ejects and being used for to prevent the slight drive pulse that makes that ink droplet jet goes out.

According to an aspect of the present invention, comprise the driving signal that is used for making a plurality of driving pulses that drop ejects and can make the slight drive pulse that drop ejects by in a print cycle, producing, thereby can in single print cycle, keep nozzle, therefore enable to improve print speed and stability.

According to another aspect of the present invention, owing to the driving pulse that makes liquid eject comprises resonant drive pulse that the natural vibration period that is used for utilizing pressure chamber makes that drop ejects and makes the resonant drive pulse of the disresonance driving pulse that liquid ejects at the natural vibration period that does not utilize pressure chamber, so stably to form the drop of big ink dot and middle ink dot at a high speed.

Description of drawings

From following detailed description, will know more in conjunction with the accompanying drawings simultaneously and understand other purpose of the present invention, feature and advantage, wherein:

Fig. 1 is the perspective view of imaging device according to one embodiment of the present invention;

Fig. 2 is the side view according to mechanism's part of the imaging device of the embodiment of the present invention;

Fig. 3 is the plane according to mechanism's part of the imaging device of the embodiment of the present invention;

Fig. 4 is the cutaway view of the partial record head cut open according to the length along its liquid chamber of first embodiment of the invention;

Fig. 5 is the cutaway view of the partial record head cut open according to the width along its liquid chamber of first embodiment of the invention;

Fig. 6 is the plane according to the record head of the embodiment of the present invention;

Fig. 7 is a block diagram, demonstrates the control module according to the imaging device of the embodiment of the present invention;

Fig. 8 is a curve map, is used to illustrate the meniscus velocity change that is caused by driving pulse according to the embodiment of the present invention;

Fig. 9 is an oscillogram, demonstrates resonant drive pulse and disresonance driving pulse according to the embodiment of the present invention;

Figure 10 is according to the curve map that demonstrates resonant drive pulse and disresonance driving pulse of the embodiment of the present invention and the curve map that demonstrates meniscus velocity change;

Figure 11 is an oscillogram, demonstrates the driving signal according to the embodiment of the present invention;

Figure 12 demonstrates forming big ink dot, middle ink dot and little ink dot and making the oscillogram of the driving signal in the situation of meniscus vibration according to the embodiment of the present invention; And

Figure 13 is an oscillogram, demonstrates according to the variation along with ink viscosity of the driving signal of the embodiment of the present invention.

The specific embodiment

With reference to these accompanying drawings embodiment of the present invention are described below.

Fig. 1 is the front-side perspective view according to the imaging device of the embodiment of the present invention.This imaging device comprises equipment body 1, sheet feed stacker 2 and paper discharge tray 3.Sheet feed stacker 2 is installed on the equipment body 1 so that hold recording paper.Paper discharge tray 3 is installed on the equipment body 1 that record (formation) has the record images paper on it so that pile up.On the upside of equipment body 1, be provided with upper side cover 4 so that can open and close.Be in the position lower in an end of the front surface 5 of equipment body 1 and be provided with print cartridge loading station 6 according to the mode of stretching out towards the front side than upper side cover 4.On the upside of print cartridge loading station 6, be provided with operation part 7 guidance panel for example that comprises operation push-button and indicator.Print cartridge loading station 6 has the front shroud 8 that can open and close on its front side.Can mount and dismount the print cartridge 9 that replenishes part as liquid by opening front shroud 8.

Fig. 2 and 3 is the side view and the plane of mechanism's part of imaging device.Mechanism's part according to imaging device, shown in Fig. 2 and 3, print cartridge 13 by as between the side plate of equipment body 1, keeping across the guide rod 11 of the guiding elements of arranging and support 12 so that can be along main scanning direction (by shown in the double-headed arrow in Fig. 3) slip.Main scan motor 17 (Fig. 7) makes balladeur train 13 move and scan along the balladeur train main scanning direction.Four record heads 14 that formed by the ink gun that is used for spraying yellow (Y), cyan (C), magenta (M) and black (Bk) respective color ink droplet so are installed on the print cartridge 13, thereby its a plurality of inkjet mouths are arranged along the direction that intersects with main scanning direction, and a plurality of inkjet mouth sprays ink droplet along downward direction.Produce part as the energy that is used for ink-jet, record head 14 can adopt piezoelectric actuator for example piezoelectric element, use electrothermal conversioning element to utilize the hot actuator of the phase transformation that the fluid film boiling causes, the electrostatic actuators of utilizing variations in temperature to cause the shape memory alloy actuator of metal phase change and utilize electrostatic force.For example, record head 14 has corresponding piezoelectric actuator.

In addition, on balladeur train 13, be equipped with as being used for holding respective color inks and the sub-ink storage chamber 15 of color inks being provided for respective record 14.From the print cartridge 9 of respective color color inks is offered corresponding sub-ink storage chamber 15 by corresponding ink supply pipe 16.Print cartridge 9 is equipped with yellow (Y), cyan (C), magenta (M) and its respective color inks of black (Bk).Be used for forming the recording liquid feeding unit to the print cartridge 9 that record head 14 provides the sub-ink storage chamber 15 of ink and replenishes ink to corresponding sub-ink storage chamber 15.

Be used for from the stacker of sheet feed stacker 2 part (pressing plate) 21 many separate and feeding recordable paper is opened 22 semilune roller (feeding-in roll) 23 with relative with paper feed roller 23 and be provided as and be used for the paper-supply section that supplying layer is stacked in the recording paper 22 on the stacker part 21 by having the branch scraps of paper 24 that form than the material of coefficient of friction greatly.To divide the scraps of paper 24 to press towards paper feed roller 23 thrusters.

In addition, as being used for the transport portion that guiding piece 25 below record head 14 begins to carry every recording paper 22 of supplying with from sheet feed stacker 2, be provided with: conveyer belt 31 is used for when allowing recording paper 21 Electrostatic Absorption thereon feeding recordable paper and opens 22; Counter roller 32 is used for carrying the recording paper of partly supplying with from paper feeding by guiding piece 25 22 when recording paper 22 being remained between counter roller 32 and the conveyer belt 31; Carry guiding piece 33, the throughput direction that is used for the recording paper 22 that will upwards supply with along the perpendicular direction changes 90 degree basically, thereby recording paper 22 is disposed thereon along conveyer belt 31; And edge rollers 35, it is pressed towards conveyer belt 31 thrusters by retaining member 34.In addition, be provided with the charging roller 36 that is used for to the live part of conveyer belt 31 surface chargings.Here, conveyer belt 31 is for engaging and be arranged on the endless belt between them according to the mode of rotating along as shown in Figure 3 tape feeding direction and conveying roller 37 and jockey pulley 38.Charging roller 36 is arranged to contact so that rotate along with the rotation of conveyer belt 31 with the superficial layer of conveyer belt 31.To charging roller 36 the axle each end apply for example pressure of 2.5N.

On another (bottom) side of conveyer belt 31, guiding elements 41 be arranged on the regional corresponding position of printing by record head 14 in.The upper surface of guiding elements 41 is arranged on record head 14 sides of tangent line of conveying roller 37 and jockey pulley 38.Therefore, in print area, conveyer belt 31 is by pressing on the upper surface of guiding elements 41 and guiding, thereby keeps flatness accurately.

Disengaging pawl 51, exit roller 52 and the exit roller 53 that is used to recording paper 22 is separated with conveyer belt 31 is provided as and is used to make the paper delivery part of having carried out recording paper 22 outputs of record on it by record head 14.Paper discharge tray 3 is arranged on exit roller 52 belows.Between position height between exit roller 52 and 53 and paper discharge tray 3, there is certain vertical range, so that can be on paper discharge tray 3 with a large amount of paper sheet stackings.

In addition, duplex paper feed unit 61 is removably mounted on the rear portion of equipment body 1.Duplex paper feed unit 61 receives the recording paper 22 that returns along with the backward rotation of conveyer belt 31.Then, duplex paper feed unit 61 makes that recording paper 22 is reverse, and again reverse recording paper 22 is delivered between counter roller 32 and the conveyer belt 31.On the upside of duplex paper feed unit 61, be provided with manual paper-supply section 62.

In addition, as shown in Figure 3, be provided with in one of them nonprinting region of scanning direction at balladeur train 13 and be used to keep with the maintenance of the reliability service portion of the condition of nozzles of recovery record 14 and recover mechanism 71, and in another nonprinting region, be provided with blank (flushing) receiving member 81 that sprays.Safeguard and recover mechanism 71 comprise block member 72a, 72b, 72c and 72d as the enclosure portion of the nozzle surface of capping respective record 14, as wiping scraper plate 73 and blank (flushing) receiving member 74 that sprays of the wiping part of wiping nozzle surface.

To adopt one of them record head 14 record head 14 to be described below as embodiment.Fig. 4 is the cutaway view of the partial record head cut open along the length of its liquid chamber.Fig. 5 is the cutaway view of the partial record head 14 cut open along the width of its liquid chamber.Fig. 6 is the plane of record head 14.Shown in Fig. 4,5 and 6, dividing plate 142 on the lower surface that each record head 14 comprises the channel plate 141 that formed by monocrystalline silicon substrate, be connected channel plate 141, be connected nozzle plate 143 and framing component 144 on the upper surface of channel plate 141, they form pressure chamber 146, flow resistance part 147 and ink supply port 149.Pressure chamber 146 is as the ink channel that is communicated with respective nozzle 145 by respective nozzle communication passage 145a.Nozzle 145 is located in the nozzle plate 143 so that allow drop therefrom eject.Flow resistance part 147 is as the ink-feed channel of the ink that offers pressure chamber 146.Ink offers flow resistance part 147 from common liquid chamber 148 by corresponding ink supply port 149.Common liquid chamber 148 is located in the framing component 144 so that preserve the ink that (storage) will offer pressure chamber 146.

As the surface that is used on the side relative, being arranged on dividing plate 142 with pressure chamber 146 to the laminated piezoelectric element 152 of the dynamo-electric conversion element of the pressure generation part that the ink that is positioned at pressure chamber 146 inside is exerted pressure.These piezoelectric elements 152 are connected on the substrate 153.Columnar stays part 154 is located between every adjacent two piezoelectric elements 152 so that corresponding with the next door part between corresponding adjacent two pressure chamber 146.Piezoelectric element 152 and columnar stays part 154 are opened that processing is divided piezoelectric element member according to the broach mode and are alternately formed mutually by adopting hemisect to carry out hemisection thereon.Columnar stays part 154 is structurally identical with piezoelectric element 151, so but because do not apply any driving voltage thereon mainly as post supports.Peripheral part of dividing plate 142 is with comprising that the bonding agent 150 of clearance component is connected on the framing component 144.Framing component 144 comprises the ink supply aperture 151 that is used for providing to common liquid chamber 148 outside ink.

In nozzle plate 143, be formed with the nozzle 145 that diameter is 10 to 35 μ m according to the mode corresponding with pressure chamber 146.Nozzle plate 143 usefulness bonding agents are connected on the channel plate 141.At the nozzle surface of nozzle plate 143 (along the surface of injection direction; Ink discharging surface) is provided with the watertight composition of handling through water-proof surface.Each piezoelectric element 152 has the lead zirconate titanate that multi-layered thickness is 10 to 50 μ m (PZT) piezoelectric layer 151 and multi-layered thickness is the alternating layer of several μ m silver palladium alloies (AgPd) interior electrode layer 162.Internal electrode 162 alternately is electrically connected with single electrode 163 and common electrode 164, and these electrodes are the end electrode (outer electrode) in the end.End electrode in an end of piezoelectric element member is divided into single electrode 163 by partly cutting, and for example cuts away and be prevented from separately so that become common electrode 164 with 152 conductings of each piezoelectric element owing to restriction processing at the end electrode of another end.FPC cable 165 by the welding, ACF (anisotropic conductive film) is bonding or wire-bonded is connected so that provide the driving signal to it with the single electrode 163 of each piezoelectric element 152.The drive circuit (driver IC) that is used for selectively applying to each piezoelectric element 152 drive waveforms is connected with each FPC cable 165.In addition, common electrode 164 is connected with ground connection (GND) electrode of FPC cable 165 by the electrode layer in the end that is located at piezoelectric element 152.

For example, if in the record head 14 that constitutes like this, apply drive waveforms (10 to 50V pulse voltages) to one of them piezoelectric element 152 according to tracer signal, displacement along stacked direction then in piezoelectric element 152, occurs so that exert pressure to the ink in relevant pressure chamber 146, thereby pressure increases to eject ink droplet from respective nozzle 145 by dividing plate 142.Afterwards, along with ink droplet jet finishes, the pressure chamber in pressure chamber 146 reduces, thereby produces negative pressure by the discharge process of China ink stream inertia and driving pulse in pressure chamber 146, therefore advances to ink and fills (supply) process.In this respect, the ink that provides from corresponding sub-ink storage chamber 15 flows to common liquid chamber 148, and flows out from common liquid chamber 148 and pass ink supply port 149 and flow resistance part 142 so that stuffing pressure chamber 146.Flow resistance part 147 is used for alleviating the residual pressure vibration after spraying, and is used as the resistance that recharges by surface tension simultaneously.Therefore,, can be implemented in alleviating and recharging balance between the time of residual pressure vibration by selecting the suitable fluid resistance of flow resistance part 147, thus can reduce advance to next ink droplet ejection operation promptly drive circulation before the required time.

The ink that is adopted in this imaging device is for example formed more than or equal to eight polyol or glycol ether, emulsion, anticorrisive agent, PH conditioning agent and pure water by pigment (from dispersant), first wetting agent, second wetting agent, solvable organic solvent, anion or non-ionic surface active agent, carbon number.As the pigment of the colouring agent of printing be used to dissolve solvent with dispersed color as key component.Wetting agent, surfactant, emulsion, anticorrisive agent and PH conditioning agent are used as additive.First and second wetting agents are mixed so that utilize the characteristic of every kind of wetting agent and be convenient to carry out viscosity control.

Pigment is not limited to particular type, can use inorganic pigment and organic pigment.For inorganic pigment, except titanium oxide and iron oxide, can use by the known method carbon black that produces of contact method, oven process and cracking process for example.In addition, for organic pigment, nitrogenous pigment (comprise azo lake, insoluble nitrogenous pigment, concentrate nitrogenous pigment and huge legendary turtle is closed nitrogenous pigment) be can adopt, encircle pigment (for example phthalocyanine color, perylene pigment, perynon pigment, anthraquinone pigment, quinoline a word used for translation (two) ketone pigment, dioxazines pigment, thioindigo pigment, isoindolinone yellow pigment and quinoline a word used for translation phthalein ketone pigment), dyestuff huge legendary turtle compound (for example, basic-dyeable fibre huge legendary turtle compound and acid dyes huge legendary turtle compound) more, contain nitropigments, nitroso pigments and nigrosine contained.

In these pigment, preferred those pigment that good affinity is arranged with glassware for drinking water that adopt.Preferably, its particle diameter of this pigment is less than or equal to 0.05 to 10 μ m, is more preferably less than or equals 1 μ m, and most preferably be less than or equal to 0.16 μ m.In addition, preferably approximately be 6 to 20wt% as the addition of pigment in ink of colouring agent, and more preferably be approximately 8 to 12wt%.

The specific embodiment of black pigment comprises carbon black (C.I. pigment black 7), for example furnace black, dim, acetylene black, channel black; Metal is copper, iron (C.I. pigment black 11) and titanium oxide for example; And organic pigment nigrosine (C.I. pigment black 1) for example.

The specific embodiment of other coloured pigment comprises C.I. pigment yellow 1 (fast yellow), 3,12 (dual-azo yellow AAA), 13,14,17,24,34,35,37,42 (yellow iron oxides), 53,55,81,83 (dual-azo yellow HR), 95,97,98,100,101,104,108,109,110,117,120,138 and 153; C.I pigment orange 5,13,16,17,36,43; C.I paratonere 1,2,3,5,17,22 (bright fast scarlets), 23,31,38,48:1 (permanent red 2B (Ba)), 48:2 (permanent red 2B (Ba)), 48:3 (permanent red 2B (Sr)), 48:4 (permanent red 2B (Mn)), 49:1,52:2,53:1,57:1 (bright dark red 6B), 60:1,63:1,63:2,64:1,81 (rhodamine 6G color lakes), 83,88,101 (colcothers), 104,105,106,108 (cadmium reds), 112,114,122 (quinoline a word used for translation (two) ketone magentas), 123,146,149,166,168,170,172,177,178,179,185,190,193,209 and 219; C.I. pigment purple 1 (rhodamine color lake), 3,5:1,16,19,23 and 38; C.I. pigment orchid 1,2,15 (pthalocyanine blue R), 15:1,15:2,15:3 (pthalocyanine blue E), 16,17:1,56,60 and 63; And C.I. naphthol green 1,4,7,8,10,17,18 and 36.

In addition, also can adopt as its surface with the resin processed so that transplanting pigment that can be dispersed in the pigment (for example carbon black) in the water with have be added in its lip-deep functional group for example sulfuryl group or hydroxyl so that can be dispersed in surface treated pigment (for example, carbon black) in the water.In addition, also can adopt and be encapsulated in the micro-capsule so that can be dispersed in pigment in the water.

According to the preference pattern of the ink that is adopted in this imaging device, preferably, the pigment that is used for black ink is as being included in the ink by using dispersant that pigment is dispersed in the pigment dispersion liquid that aqueous solvent obtains.The preferred embodiment of dispersant comprises according to acrylic acid, polymethylacrylic acid, acrylic acid-acrylonitrile copolymer, the vinyl acetate-acrylate copolymer, acrylic acid-alkyl acrylate copolymer, the styrene-propene acid copolymer, styrene-methacrylic acid copolymer, styrene-propene acid-alkyl acrylate copolymer, styrene-methacrylic acid-alkyl acrylic copolymer, styrene--acrylic copolymer, styrene--acrylic acid-alkyl acrylate copolymer, styrene-maleic acid copolymer, vinyl naphthalene-maleic acid, vinylacetate-ethylene copolymer, vinylacetate-fatty acid vinyl-ethylene copolymer, vinylacetate-maleate copolymer, vinylacetate-crotonic acid copolymer, and vinylacetate-acrylic copolymer.

Its weight average molecular weight of these copolymers is preferably 3000-50000, and more preferably 5000 to 30000, and most preferably be 7000 to 15000.Can suitably determine the addition of dispersant, as long as this pigment stably disperses and can not lose other effect.Pigment-dispersive agent ratio is preferably in 1: 0.06 to 1: 3 scope, and more preferably in 1: 0.125 to 1: 3 scope.

Ratio as the gross weight of the pigment of colouring agent and ink is 6wt% to 20wt%.Its particle diameter of the particle of pigment is less than or equal to 0.05 μ m to 0.16 μ m, and is dispersed in the water by dispersant.Dispersant is 5000 to 100000 polymeric dispersant for its molecular weight.Can improve picture quality by water-soluble organic solvent by use pyrrolidinone derivatives especially 2-Pyrrolidone as at least a.

For first wetting agent, second wetting agent and can water-soluble organic solvent for, for example so use following can water-soluble organic solvent, thereby this ink has desired physical property and has prevented ink dried, but some inks adopt water as liquid medium therein.Can also use these two or more mixtures in can water-soluble organic solvent.

Wetting agent and specific embodiment that can water-soluble organic solvent comprise polyalcohol for example ethylene glycol, diethylene glycol (DEG), triethylene glycol, propane diols, DPG, tripropylene glycol, tetraethylene glycol, hexylene glycol, polyethylene glycol, polypropylene glycol, 1,5-pentanediol, 1,6-hexylene glycol, glycerine, 1,2,6-hexanetriol, 1,2,4-butantriol, 1,2,3-butantriol and petriol; Polyol alkyl ether is ethylene glycol monoethyl ether, ethylene glycol-butyl ether, diethylene glycol (DEG) monoethyl ether, diethylene glycol-butyl ether, tetraethylene glycol monoethyl ether and propane diols monoethyl ether for example; The polyalcohol aryl ether is ethylene glycol one phenyl ether and ethylene glycol one benzyl ether for example; Nitrogen-containing heterocycle compound is 2-Pyrrolidone, N-N-methyl-2-2-pyrrolidone N-, N-ethoxy-2-Pyrrolidone, 1 for example, 3-dimethyl-2-imidazolone and epsilon-caprolactams; Amides compound is formamide, N-methyl nitrosourea and N for example, the N-dimethylformamide; Aminated compounds is monoethanolamine, diethanol amine, triethanolamine, monoethyl amine, diethylamine and triethylamine for example; Sulfur-containing compound is methyl-sulfoxide, sulfolane and thiodiglycol for example; Propylene carbonate; And vinyl carbonate.

In these organic solvents, especially preferably adopt ethylene glycol, thiodiglycol, polyvinyl alcohol 200-600, triethylene glycol, glycerine, 1,2,6-hexanetriol, 1,2,4-butantriol, petriol, 1,5-pentanediol, 2-Pyrrolidone and N-N-methyl-2-2-pyrrolidone N-.These organic solvents are the performance excellence in solubility and aspect the inkjet performance variation that prevents to cause owing to the aqueous vapor evaporation.

Other preferred embodiment of wetting agent includes saccharide compound.The example of saccharide compound comprises monose, disaccharides, compound sugar (comprising trisaccharide and tetrose) and polysaccharide.In those, preferably adopt glucose, mannose, fructose, ribose, wood sugar, arabinose, galactolipin, maltose, cellobiose, lactose, sucrose, trehalose and maltotriose.Here, polysaccharide will carry out extensive interpretation, and is used in reference to the material that generation is included in extensive existence in the nature, for example alpha-cyclodextri and cellulose.In addition, the derivative of these carbohydrates comprises the reducing sugar of above-mentioned saccharide compound (sugar alcohol for example, it is by general formula HOCH ₂(CHOH) _nCH ₂OH represents that wherein n is 2 to 5 integer); The oxosugar of above-mentioned carbohydrate (for example glycuronic acid and uronic acid); Amino acid; And thio-acid.Especially preferably adopt sugar alcohol.The embodiment of sugar alcohol comprises maltitol and D-sorbite.

The content of carbohydrate be preferably ink composition 0.1 to 40wt%, and be preferably 0.5-30wt%.

Surfactant is not particularly limited.The embodiment of anion surfactant comprises polyethylene glycol oxide-alkyl ether-acetate (polyoxyethylenealkyletheracetate), dodecyl benzenesulfonyl (dodecylbenzenesulfonates), laurate (laurylates) and polyethylene glycol oxide-alkyl ether-sulfuric ester (polyoxyethylenealkylethersulfates).The embodiment of non-ionic surface active agent comprises polyethylene glycol oxide-alkyl ether (polyoxyethylenealkylether), polyethylene glycol oxide-Arrcostab (polyoxyethylenealkylester), polyoxyethylenesorvitane fatty acid ester, polyethylene glycol oxide-alkyl-phenyl ether (polyoxyethylenealkylphenylether), polyethylene glycol oxide-alkylamine (polyoxyethylenealkylamine) and polyethylene glycol oxide-alkylamide (polyoxyethylenealkylamide).Can use each of above-mentioned surfactant separately.Also can use and be used in combination in the above-mentioned surfactant two or more.

The surface tension of employed ink is the index that penetrates in the paper in imaging device, especially be illustrated in the surface form after smaller or equal to the dynamic surface tension in 1 second short time, therefore with on the surface when saturated measured static surface tension different.Can adopt the measuring method of any conventional,, for example specially permit the method disclosed in the publication application No.63-31237 in Japan as long as this method can be measured smaller or equal to the dynamic surface tension in 1 second time.Here, use the Wilhelmy plate dynamometer to come surface tension.Preferably, surface tension is less than or equal to 40mJ/m ², and be more preferably less than or equal 35mJ/m ²This number range enables to obtain good fixation and drying property.

For amount of carbon atom more than or equal to for 8 the many alcohol or glycol ether, have been found that by add to the gross weight of ink its dissolubility in 25 ℃ of water of 0.1 to 10.0wt% 0.1 and can water-soluble how pure and mild ethylene glycol less than the part between the 4.5wt% at least a, thereby can improve the wettability of ink, even and add and also can obtain jetting stability and frequency stability on a small quantity with respect to thermal element.For example, 2-vinyl-1, its dissolubility of 3-ethylene glycol is 4.2% (20 ℃), and 2,2,4-trimethyl-1, its dissolubility of 3-pentanediol is 2.0% (25 ℃).Its dissolubility in 25 ℃ of water still has the very high advantage of permeance property 0.1 and lower less than its dissolubility of the bleeding agent between the 4.5wt%.Therefore, can by with its in 25 ℃ of water dissolubility 0.1 and less than the bleeding agent between the 4.5wt% and another kind of solvent or combinations-of surfactants produce have unusual high osmosis can ink.

In addition, preferably, employed ink comprises resin emulsion as additive in this imaging device.The resin emulsion here refers to has the emulsion of water as continuous phase and this resin Composition as decentralized photo as described below.The embodiment of the resin Composition of decentralized photo comprises acrylic resin, vinyl acetate-based resin, styrene-butadiene base resin, vinyl chloride-based resin, propylene-styrene base resin, butadienyl resin and styrene base resin.According to the optimal way of the ink of this embodiment, resin is preferably the polymer with hydrophilic segment and hydrophobic part.In addition, the particle diameter of resin Composition is not particularly limited, as long as this resin Composition can form emulsion.But particle diameter preferably is less than or equal to about 150nm, and more preferably is approximately 5 to 100nm.Can be by with resin particle and water and be mixed together with surfactant in some cases and prepare resin emulsion.For example, can be by with (methyl) acrylate or styrene and (methyl) acrylic ester mixed merging and surfactant is mixed with water prepare acrylic resin or styrene-propene base resin in some cases.In general, resin Composition-surfactant mixture ratio is preferably 10: 1 to 5: 1.If the use amount of surfactant is less than above-mentioned scope, then be not easy to form emulsion.On the other hand, it is not preferred using the surfactant that surpasses above-mentioned scope, because the water proofing property of ink can reduce or the permeance property of ink can variation.

Water adds 60 to 400 parts of water that are preferably 100 to 200 parts for per 100 parts of resins by weight with proper proportion as the resin of the dispersed phase component of emulsion.

The embodiment of commercially available resin emulsion comprises that Micro gel E-1002 and E-5002 are (by NipponPaint Co., Ltd. the styrene-propene base resin emulsion that produces), Boncoat 4001 (the acrylic resin emulsion that produces by Dai NipponInk and Chemical Inc.), Boncoat 5454 (the styrene-propene base resin emulsion that produces by Dai NipponInk and Chemical Inc.), SAE-1014 (the styrene-propene base resin emulsion that produces by ZeonCorp.) and Saivinol SK-200 (by SaidenChemical Industry Co., the acrylic resin emulsion that Ltd. makes).This resin emulsion contains such component, its resin Composition be preferably ink 0.1 to 40wt%, more preferably it is 1 to 25wt%.

Aforesaid resin emulsion has the performance of thickening and gathering, and has and prevent colouring component infiltration and promote colouring component to be affixed to the effect on the recording materials.In addition, the resin emulsion of some types forms coating on recording materials, produces the effect that improves the printed material rub resistance thus.

In addition, can use anticorrisive agent and fungicide for example sodium dehydroacetate, sodium sorbate, 2-mercaptopyridine-1-oxide, sodium, Sodium Benzoate and sodium pentachlorophenol as additive.

As the PH conditioning agent, can use arbitrarily can be under the situation that prepared ink is not caused negative effect PH to be adjusted to 7 or higher material.The embodiment of PH conditioning agent comprises aminated compounds for example diethanol amine and triethanolamine; Alkali metal hydroxide is lithium hydroxide, NaOH and potassium hydroxide for example; Ammonium hydroxide; Quaternary ammonium hydroxide; The hydroxide quaternary phosphonium; Alkali carbonate is lithium carbonate, sodium carbonate and potash for example.As chelating agent, for example can adopt ethylenediaminetetraacetic acid tetrasodium salt, nitrilo-acetate trisodium, AEEA acetate trisodium, Diethylenetriamine acetate five sodium and uramil acetate disodium.As antirust agent, can adopt for example acid sulphite, sodium thiosulfate, ATS (Ammonium thiosulphate), diisopropylamine nitrite, four nitric acid pentaerythrite and dicyclohexylamine nitrites.

Fig. 7 is a block diagram, demonstrates the control module 100 according to the imaging device of this embodiment.With reference to Fig. 7, control module 100 comprises control section 101, turntable driving part 102 and record head drive part 103.Control section 101 comprises that main control part 104, main interface (I/F) 105, storage area 106, pulse spacing storage area 107 and driving signal generator divide 108.Main control part 104 is being controlled the operation of entire equipment.Main I/F105 and main equipment exchange wide range of information projects.Storage area 106 has been stored the information that sends out from each control program and main equipment.Drive signal generator and divide 108 to produce the driving signal that comprises driving pulse and slight drive pulse, and will drive signal and export to record head drive part 103.Driving signal makes ink droplet eject from respective nozzle 145 according to print signal that sends out from main control part 104 and the pulse spacing that is stored in the pulse spacing storage area 107.Slight drive pulse makes the ink meniscus in relevant pressure chamber 146 vibrate, and can not make that ink droplet jet goes out.Turntable driving part 102 is connected with subscan motor 18 with main scan motor 17.Record head drive part 103 is connected with record head 14.Main control part 104 is connected with operation part 7.

From the nozzle 145 of record head 14, ejecting under the situation of ink droplet, if as eject ink by a driving pulse P from nozzle 145 as shown in (a) of Fig. 8, then the meniscus velocity of the ink in pressure chamber 146 is carried out damping vibration according to the natural vibration period of pressure chamber 146.With reference to (b) of Fig. 8, by drive signal generator divide 108 produce and output so as from nozzle 145, to eject the driving signal of ink droplet comprise be used for the resonant drive pulse Pr (Fig. 9) of the natural vibration period Tc resonance of the pressure chamber 146 of record head 14 and not can with the disresonance driving pulse of the natural vibration period Tc resonance of pressure chamber 146.Resonant drive pulse Pr is used for combining the volume that increase ink droplet by the ink droplet that will be ejected by first (formerly) driving pulse with by the ink droplet that subsequently second driving pulse ejects aloft.

Pulse spacing refers to the driving pulse that ejects at the nozzle 145 that is used for making ink from record head and its interval between the driving pulse formerly.As shown in Figure 9, be used for producing with the pulse spacing Tr (Fig. 9 (a)) of the resonant drive pulse Pr of the natural vibration period resonance of pressure chamber 146 and be used to produce not and can be stored in pulse spacing storage area 107 in advance with the pulse spacing Tn (Fig. 9 (b)) of the resonant drive pulse Pn of the natural vibration period resonance of pressure chamber 146.Be stored in pulse spacing Tr in the pulse spacing storage area 107 with respect to the natural vibration period Tc of pressure chamber 146, that is to say and making the vibration period Tc of ink meniscus velocity when nozzle 145 ejects by a driving pulse, be defined as Tr=m * Tc (m≤2), for example Tr=(2Tc ± 0.5) μ s.Pulse spacing is defined as the non-integral multiple of natural vibration period Tc, and Tn=(m+1/4) * Tc to Tn (m+3/4) * Tc for example is promptly in the anti-phase zone of pressure chamber's 146 natural vibrations.Specifically, pulse spacing Tn is limited in the scope of Tn=(m+1/3) * Tc to Tn (m+2/3) * Tc.Here, owing to following reason decision m≤2.As shown in (b) of Fig. 8, make resonant drive pulse Pr one of them peak m=1-3 place resonance in meniscus velocity change.But, if make resonant drive pulse Pr, be used in waveform then make that the position of resonant pulses Pr resonance is far away at peak m=3 place resonance, promptly Tr is longer the pulse spacing, and therefore making it can not raising speed.Therefore, the pulse spacing Tr of resonant drive pulse Pr is defined as Tr=m * Tc (m≤2) with respect to the natural vibration period Tc of pressure chamber 146, has improved print speed thus.

If order produces a plurality of resonant drive pulse Pr, then the meniscus velocity that is produced by resonant drive pulse Pr is subjected to by its influence of the meniscus velocity that produces of resonant drive pulse Pr formerly, thereby increases gradually.For example, if the pulse spacing Tr that m is defined as m=2 and will be used to produce resonant drive pulse Pr is defined as Tr=2Tc and as being defined as Tn=(7/3) Tc and Tn=(8/3) Tc at the same pulse spacing Tn that will be used to produce disresonance driving pulse Pn as shown in the driving signal of the resonance of Figure 10 (a) and disresonance driving pulse, then the meniscus velocity that produces by this resonant drive pulse Pr and disresonance driving pulse Pn is as changing as shown in Figure 10 (b).Producing by order just under the resonant drive pulse below the m=2 makes the situation that ink ejects, the meniscus velocity of the 4th drop is as more too much greatly than the meniscus velocity of the 3rd drop as shown in Figure 10 (b), and it is unstable to make that therefore ink sprays.Therefore, this can not carry out actual use.Therefore, do not have to select and can only select as the m in the situation that only is to use resonant drive pulse Pr to drive greater than 2 numerical value.This makes and drives wavelength lengthy, therefore makes it to improve speed.Therefore,, use disresonance driving pulse Pn to make ink be injected into the 3rd ink droplet, suppressed the meniscus velocity when the resonant drive pulse Pr that uses m=2 sprays the 4th ink droplet thus and guaranteed stability according to this embodiment.Meniscus velocity when using resonant drive pulse Pr to spray in order to be suppressed at, the pulse spacing Tn that will be used for producing disresonance driving pulse Pn is defined as the anti-phase zone in the natural vibration of pressure chamber 146, promptly in the scope of Tn=(m+1/4) * Tc to Tn (m+3/4) * Tc, Tn (7/3) Tc to Tn=(8/3) Tc specifically.Therefore, suppress meniscus velocity, thereby can guarantee stability.In addition, so reduce pulse spacing Tn, thereby can improve print speed.That is to say, when utilizing resonant drive pulse Pr to spray, suppress under the situation of meniscus velocity,, then can not when spraying, suppress meniscus velocity if used the phase region identical with resonant drive pulse Pr by employing disresonance driving pulse Pn.Therefore, the pulse spacing that will be used for producing disresonance driving pulse Pn is defined as being in the anti-phase zone of natural vibration of pressure chamber 146, promptly in the scope of Tn=(m+1/4) * Tc to Tn (m+3/4) * Tc.

Turntable driving part 102 drives main scan motor 17 and subscan motor 18 according to the control signal of supplying with from main control part 104.Record head drive part 103 is according to dividing 108 each record head 14 of drive of exporting from driving signal generator.

Next will be in this imaging device, dividing the driving signal that produces in 108 to describe at the driving signal generator by making ink droplet from the nozzle 145 of record head 14, eject under the situation of recording paper 22 formation images.

As shown in the oscillogram of Figure 11, in a print cycle, divide the driving signal that produces in 108 to comprise to be used to cause a plurality of driving pulse P1 and the P3 to P7 of ink droplet jet and be used under the situation that does not cause ink droplet jet, making the slight drive pulse P2 of meniscus vibration driving signal generator.Driving pulse P1 and P3 to P7 comprise a plurality of resonant drive pulse Pr and one or more disresonance driving pulse Pn that do not utilize the resonance of pressure chamber 146 that utilize the resonance increase droplet volume of pressure chamber 146.The waveform of each driving pulse comprise the waveform portion Pa that pressure chamber 146 is expanded, the chamber 146 that keep-ups pressure swelling state waveform portion Pb and make the waveform portion Pc that bulbs of pressure chamber 146 shrinks.Drive signal generator divide 108 according to the print signal Ps1, the Ps2 that send from main control part 104 or Ps3 or signal Ps4 to the one or more pulses of record head drive part 103 outputs.For example, at the print signal Ps1 that is used for big ink dot when main control part 104 is sent, as shown in the oscillogram of Figure 12 (a), exporting slight drive pulse P2 and driving pulse P3 to P7.At the print signal Ps2 that is used for ink dot when main control part 104 is sent, output driving pulse P4 to P6 shown in Figure 12 (b).At the print signal Ps3 that is used for little ink dot when main control part 104 is sent, output driving pulse P1 shown in Figure 12 (c).Therefore, by forming single ink dot from a plurality of pulses that driving pulse produces part 108 outputs according to print signal Ps1, Ps2 or Ps3.In addition, the signal Ps4 that can not cause ink droplet jet making meniscus vibration when main control part 104 is sent, output slight drive pulse P2 shown in Figure 12 (d).When driving signal generator and dividing in 108 this slight drive pulse of output P2, record head drive part 103 is just given providing vibration so that make the meniscus vibration that produces in these nozzles 145 with all nozzles 145 in nonprinting region and the ink that do not print in print area in the corresponding pressure chamber 146 of those nozzles 145 of operation, has prevented the spray nozzle clogging that causes owing to the ink exsiccation thus.

For example, the driving signal of ink dot in being used to form shown in Figure 12 (b) equally when driving signal generator and divide 108 outputs, by the first driving pulse P4 ink dot of winning is ejected from nozzle 145, make second ink dot from nozzle 145, eject by the second driving pulse P5 afterwards as the resonant drive pulse Pr that exports with pulse spacing Tr.Here, driving pulse P4 is identical on parameter with driving pulse P5.But, by utilizing the vibration of the pressure chamber 146 of reservation ejecting first ink droplet after by driving pulse P4, thus can so that the speed of second ink droplet that ejects by driving pulse P5 greater than the speed of first ink droplet that ejects by driving pulse P4.Second ink droplet that is ejected by driving pulse P5 aloft merges with first ink droplet that is ejected by driving pulse P4.In addition, drive signal generator and divide the 108 driving pulse P5 that after driving pulse P4 is exported to record head drive part 103, export as resonant drive pulse Pr, utilize the resonance of pressure chamber 146 to improve expulsion pressure thus.Therefore, and in the situation that causes separately injection, compare, can spray the bigger ink droplet of volume by driving pulse P5.In this state, make the 3rd drops out from nozzles 145 eject so that before dropping on recording paper 22, merge by the 3rd driving pulse P6, ink dot on recording paper 22, forming thus with second ink droplet that has combined with first ink droplet.Because the 3rd driving pulse P6 is non-resonant drive pulse Pn, so the 3rd driving pulse P6 does not utilize the resonance of pressure chamber 146.Therefore, the ink that is ejected can not occur spraying crooked.That is to say, and be used for that the second driving pulse P5 is the same to adopt resonant drive pulse Pr to cause extraordinary efficient for the 3rd driving pulse P6, too big thereby the residual oscillation of the meniscus after ink droplet jet becomes.If ink viscosity is too low, then can not prevent the ink droplet bending of being ejected.Therefore, in order to be very difficult for this to happen, adopt non-resonant pulse Pn as the 3rd driving pulse P6.

Therefore can form the ink droplet of preliminary dimension efficiently, and make it stably to drop on the pre-position on the recording paper 22.

In addition, shown in Figure 12 (a) when driving signal generator and divide 108 outputs to be used to form the driving signal of big ink dot, so can not eject any ink droplet by the first driving pulse P2 because the first driving pulse P2 is a slight drive pulse.But, thereby can be by making the meniscus vibration of nozzle 145 with driving pulse P2 and under this state, making ink droplet jet come out to increase the droplet volume that will spray with the second driving pulse P3.In addition, after from nozzle 145, ejecting first ink droplet, from nozzle 145, eject second ink droplet so that merge with first ink droplet aloft by the 3rd driving pulse P4 with the second driving pulse P3.In this state, by the 4 wheel driven artery eject the 3rd ink droplet towards P5 from nozzle 145 in case hollow with and second ink droplet that combines of first ink droplet merge, increased volume thus.Then from nozzle 145, eject the 4th ink droplet and the 5th ink droplet by the 5th driving pulse P6 and the 6th driving pulse P7 respectively.Therefore, these ink droplets combined before dropping on the recording paper 22 one by one, formed big ink dot thus on recording paper 22.Owing in these pulses that are used to form big ink dot, include slight drive pulse P2, thus during printing without any need for the signal length that is exclusively used in slight drive pulse P2, therefore can not cause any obstruction to flying print.

Therefore divide to produce in 108 in a print cycle, to have at the driving signal generator and be used to cause the driving signal P1 of ink droplet jet and the driving signal of P3 to P7 and the slight drive pulse P2 that is used to make meniscus vibration and can not cause ink droplet jet.The meniscus vibration that meniscus vibration after driving pulse P1 and P3 to P7 spray ink droplet and slight drive pulse P2 cause is according to ink viscosity and different.When ink viscosity was higher, vibration had less amplitude.For this meniscus vibration is remained under the predetermined condition, according to ink viscosity, be that the viscosity of ink in atmospheric environment is selected or the peak value of definite driving pulse P1 and P3 to P7 and slight drive pulse P2, as shown in figure 13, this figure is the oscillogram that drives signal when the ink viscosity of 2mPas, 10mPas and 20mPas.Therefore, can be so that meniscus stably vibrate, thus can form ink droplet with predetermined.In addition, can also prevent stably that nozzle 145 from stopping up.

According to an embodiment of the invention, provide a kind of like this imaging device, it comprises: record head, and it comprises the nozzle of liquid droplets therefrom, is communicated with nozzle and is equipped with the pressure chamber of liquid and the pressure generation part that changes pressure chamber's volume; And driving signal generator branch, be configured to produce the driving signal that comprises a plurality of driving pulses, this driving signal makes the pressure generation part of record head so operate, thereby from nozzle, eject drop, wherein comprise that by driving driving signal that the signal generator branch produces the natural vibration period that is used for utilizing pressure chamber makes the resonant drive pulse that first drop ejects in single print cycle, be used under the situation of the natural vibration period that does not utilize pressure chamber, making disresonance driving pulse that second drop ejects and being used for to prevent the slight drive pulse that makes that ink droplet jet goes out.

According to an aspect of the present invention, comprise the driving signal that makes a plurality of driving pulses that liquid ejects and can not make the slight drive pulse that drop ejects by in single print cycle, producing, can in single print cycle, keep nozzle, therefore enable to improve the speed and the stability of printing.

According to another aspect of the present invention, because the driving signal that makes drop eject comprises the resonant drive pulse that the natural vibration period that utilizes pressure chamber makes that drop ejects and do not utilize the natural vibration period of pressure chamber to make the disresonance driving pulse that drop ejects, so can be stably to form big ink dot and middle ink dot drop at a high speed.

In addition, in above-mentioned imaging device, driving the signal generator branch can determine in resonant drive pulse and the pulse spacing between one of them driving pulse before this resonant drive pulse with respect to the natural vibration period of pressure chamber, thereby the pulse spacing is satisfied Tr=m * Tc, wherein Tr is the pulse spacing, Tc is the natural vibration period of pressure chamber, and m is less than or equal to 2 numerical value.

Therefore, reduce pulse spacing Tr, thereby can improve print speed.

In addition, in aforesaid imaging device, driving the signal generator branch can determine in disresonance driving pulse and the pulse spacing between one of them driving pulse before this disresonance driving pulse with respect to the natural vibration period of pressure chamber, thereby should the pulse spacing in the scope of Tn=(m+1/4) * Tc to Tn=(m+3/4) * Tc, especially Tn=(m+1/3) * Tc to Tn=(m+2/3) * Tc, wherein Tn is the pulse spacing, Tc is the natural vibration period of pressure chamber, and m is less than or equal to 2 numerical value.

Therefore, utilize the disresonance driving pulse to suppress meniscus velocity under continuous injection ink droplet situation, guaranteed stability thus.Therefore, can improve print speed.

In addition, in aforesaid imaging device, driving the signal generator branch can determine in resonant drive pulse and first pulse spacing between one of them driving pulse before this resonant drive pulse with respect to the natural vibration period of pressure chamber, thereby first pulse spacing was satisfied Tr=2Tc ± 0.5 μ m, and can determine in disresonance driving pulse and second pulse spacing between one of them driving pulse before this disresonance driving pulse, thereby second pulse spacing is in the scope of Tn=7Tc/3 to 8Tc/3, wherein Tr was first pulse spacing, second pulse spacing of Tn, and Tc is the natural vibration period of pressure chamber.

Therefore, can stably carry out high-frequency drive.

In addition, drive the signal generator branch and can produce driving signal according to the print signal that is used to form single ink dot with different driving signal combination.

Therefore, can stably form the drop of certain size according to print signal.

In addition, in aforesaid imaging device, driving signal generator branch can produce has the and then driving signal of the disresonance driving pulse after resonant drive pulse.

Therefore, can stably form the second best in quality image by the bending that suppresses institute's liquid droplets.

In addition, in aforesaid imaging device, drive the signal generator branch and can so produce slight drive pulse, thereby this slight drive pulse is arranged in single print cycle and makes between a plurality of driving pulses that ink droplet jet goes out, and can produce one of them driving pulse under the situation of nozzle meniscus vibration making by this slight drive pulse.

Therefore, can increase the droplet size that from nozzle, ejects.

In addition, in aforesaid imaging device, thereby can comprise first waveform portion that makes pressure chamber expand the meniscus of nozzle is gone into towards pressure chamber's layback and make second waveform portion that bulbs of pressure chamber shrinks driving driving pulse that signal generator produces in dividing and in the slight drive pulse each.

Therefore, can guarantee the further raising of nozzle maintenance and print speed.

In addition, in aforesaid imaging device, driving the signal generator branch can change each peak value in driving pulse and the slight drive pulse according to the viscosity of liquid in environment for use, and liquid can have the viscosity of 2mPas to 20mPas.

Therefore, can stably make meniscus vibration, thereby can form drop with predetermined.In addition, can also prevent spray nozzle clogging.

The invention is not restricted to top specifically described embodiment, can make many variations and modification without departing from the scope of the invention.

The application is based on the Japan of submitting on December 5th, 2005 formerly patent application No.2005-350090 and the No.2006-273543 that submitted on October 5th, 2006, and the full text of these documents here is cited as a reference.

Claims (11)

1. imaging device, it comprises:

Record head, it comprises the nozzle of liquid droplets therefrom, is communicated with nozzle and is equipped with the pressure chamber of liquid and the pressure generation part that changes pressure chamber's volume; And

Driving signal generator branch is configured to produce the driving signal that comprises a plurality of driving pulses, and this driving signal makes the pressure generation part of record head operate, thereby ejects drop from nozzle,

Wherein by drive resonant drive pulse that driving signal that the signal generator branch produces comprises that in single print cycle the natural vibration period that is used for utilizing pressure chamber makes first drop eject, be used for make under the situation of the natural vibration period that does not utilize pressure chamber disresonance driving pulse that second drop ejects and make in the relevant pressure chamber the ink meniscus vibration and can not make the slight drive pulse that ink droplet jet goes out.

2. imaging device as claimed in claim 1, wherein driving the signal generator branch determines in resonant drive pulse and the pulse spacing between one of them driving pulse before this resonant drive pulse with respect to the natural vibration period of pressure chamber, thereby the pulse spacing is satisfied Tr=m * Tc, wherein Tr is the pulse spacing, Tc is the natural vibration period of pressure chamber, and m is less than or equal to 2 numerical value.

3. imaging device as claimed in claim 1, wherein driving the signal generator branch determines in disresonance driving pulse and the pulse spacing between one of them driving pulse before this disresonance driving pulse with respect to the natural vibration period of pressure chamber, thereby should the pulse spacing in the scope of Tn=(m+1/4) * Tc to Tn=(m+3/4) * Tc, wherein Tn is the pulse spacing, Tc is the natural vibration period of pressure chamber, and m is less than or equal to 2 numerical value.

4. imaging device as claimed in claim 1, wherein driving the signal generator branch determines in disresonance driving pulse and the pulse spacing between one of them driving pulse before this disresonance driving pulse with respect to the natural vibration period of pressure chamber, thereby should the pulse spacing in the scope of Tn=(m+1/3) * Tc to Tn=(m+2/3) * Tc, wherein Tn is the pulse spacing, Tc is the natural vibration period of pressure chamber, and m is less than or equal to 2 numerical value.

5. imaging device as claimed in claim 1, wherein driving the signal generator branch determines in resonant drive pulse and first pulse spacing between one of them driving pulse before this resonant drive pulse with respect to the natural vibration period of pressure chamber, thereby first pulse spacing was satisfied Tr=2Tc ± 0.5 μ s, and determine in disresonance driving pulse and second pulse spacing between one of them driving pulse before this disresonance driving pulse, thereby second pulse spacing is in the scope of Tn=7Tc/3 to 8Tc/3, wherein Tr was first pulse spacing, and Tn was second pulse spacing, and Tc is the natural vibration period of pressure chamber.

6. imaging device as claimed in claim 1 wherein drives the signal generator branch and produces the driving signal with different driving signal combination according to the print signal that is used to form single ink dot.

7. imaging device as claimed in claim 1, wherein, driving signal generator branch produces has the and then driving signal of the disresonance driving pulse after resonant drive pulse.

8. imaging device as claimed in claim 1, wherein drive the signal generator branch and produce slight drive pulse, make this slight drive pulse in single print cycle, be arranged on to make between a plurality of driving pulses that ink droplet jet goes out, and produce the driving pulse that one of them makes that drop ejects under the situation of nozzle meniscus vibration making by this slight drive pulse.

9. imaging device as claimed in claim 1, thus wherein comprise first waveform portion that makes pressure chamber expand the meniscus of nozzle is gone into towards pressure chamber's layback and make second waveform portion that the pressure chamber of expanding shrinks in making of driving that signal generator produces in the dividing driving pulse that drop ejects and in the slight drive pulse each.

10. imaging device as claimed in claim 1 wherein drives the signal generator branch and changes according to the viscosity of liquid in environment for use and make driving pulse that drop ejects and each the peak value in the slight drive pulse.

11. imaging device as claimed in claim 1, wherein said liquid has the viscosity of 2mPas to 20mPas.

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