JP2012161917A - Liquid ejecting apparatus and control method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly control the strength of micro vibration given to each pressure chamber.SOLUTION: The liquid ejecting apparatus 100 includes; the pressure chamber 50 filled with liquid; a nozzle 56 communicated to the pressure chamber 50; and a pressure development element 45 for varying the pressure in the pressure chamber 50, respectively, and includes: a plurality of jetting parts J capable of jetting the liquid from the nozzle 56 according to variation of the pressure in the pressure chamber 50; a control part 60 which controls the pressure development element 45, and causes the jetting part J to jet the liquid or to perform micro vibration driving for oscillating a liquid surface in the nozzle 56 to the extent that the liquid is not jetted from the nozzle 56 in each control cycle T. The control part 60 changes the strength of micro vibration driving performed by the first jetting part J1 in the control circle T according to whether the second jetting part J2 nearest the first jetting part J1 among the plurality of jetting parts J jets the liquid in the control circle T when the first jetting part J1 among the plurality of jetting parts J does not jet the liquid in the control circle T.

Description

  The present invention relates to a technique for ejecting a liquid such as ink.

  Conventionally, a liquid ejecting technique has been proposed in which a liquid (for example, ink) in a pressure chamber is ejected from a nozzle by vibrating the pressure chamber by a pressure generating element such as a piezoelectric vibrator or a heating element. An ink jet recording head that employs liquid ejecting technology includes a plurality of pressure chambers that communicate with nozzles, a reservoir that is a common liquid chamber that communicates with each pressure chamber, and droplets from the nozzles by changing the pressure in the pressure chambers. Pressure generating means for injecting the gas. As the pressure generating means, for example, a longitudinal vibration type piezoelectric element, a flexural vibration type piezoelectric element, an element using electrostatic force, a heating element, or the like is employed.

  Ink jet recording heads have a problem in that the ink solvent evaporates from the free surface (meniscus) of the ink exposed in the nozzles, the ink is thickened, the ink ejection characteristics change, and the printing accuracy decreases. . Therefore, a configuration in which fine vibration driving that slightly vibrates the meniscus to the extent that ink is not ejected is performed every recording period (one period of the driving waveform), and the ink in the vicinity of the nozzle is stirred to maintain the ink at an appropriate viscosity. Adopted (for example, Patent Document 1). In the technique of Patent Document 1, the intensity of micro vibration is changed according to the amount of ink ejected from the nozzle.

JP 2001-270134 A

  Ink in the pressure chamber propagates vibration (that is, vibration due to crosstalk) when ink is ejected from the pressure chamber located around the ink. Therefore, in the technique of Patent Document 1 in which the intensity of micro-vibration is controlled considering only the ink ejection amount from the nozzle to be controlled, there is a possibility that the ink in the pressure chamber corresponding to the nozzle is excessively agitated. is there. In view of the above circumstances, an object of the present invention is to appropriately control the intensity of microvibration applied to each pressure chamber.

  In order to solve the above problems, a liquid ejecting apparatus of the present invention includes a pressure chamber filled with a liquid, a nozzle communicating with the pressure chamber, and a pressure generating element that varies the pressure in the pressure chamber. A plurality of jetting units capable of jetting the liquid from the nozzle in accordance with pressure fluctuations in the pressure chamber, and controlling the pressure generating element to jet the liquid or the liquid level in the nozzle. And a control unit that causes the ejection unit to execute micro-vibration driving that swings to such an extent that the liquid is not ejected at each control cycle, wherein the control unit includes the plurality of ejection units. If the first ejection unit of the first injection unit does not eject the liquid in the control cycle, the second ejection unit closest to the first ejection unit among the plurality of ejection units ejects the liquid in the control cycle. Depending on the control cycle Serial first injection unit alters micro-vibration driving of intensity (intensity of the minute vibrations imparted to the liquid surface in the nozzle by the minute vibration drive) to run.

  In the above configuration, the strength of the micro-vibration driving applied to the meniscus in the nozzle of the first ejection unit that does not eject liquid in the printing cycle is determined from the nozzle of the second ejection unit closest to the first ejection unit. Since the control is performed according to whether or not the liquid is ejected at the pressure of the first ejection unit, even when the vibration during the ejection of the liquid from the nozzle of the second ejection unit propagates to the pressure chamber of the first ejection unit. Application of excessive vibration to the liquid in the room is suppressed. Therefore, there is an advantage that the power consumption required for the micro-vibration driving can be reduced and the operating life of the pressure generating element can be extended because the vibration of the pressure generating element is suppressed.

In a preferred aspect of the present invention, the plurality of injection units include a third injection unit that is located on the opposite side of the second injection unit with respect to the first injection unit and is closest to the first injection unit, When the first ejecting unit does not eject the liquid in the control cycle, when only one of the second ejecting unit or the third ejecting unit ejects the liquid in the control cycle, When the first jetting unit is caused to perform a fine vibration drive of one strength and both the second jetting unit and the third jetting unit jet the liquid in the control cycle, the second lower than the first strength. The first injection unit is caused to execute a strong micro vibration drive.
According to the above aspect, when the liquid is ejected from only one nozzle of the second ejection unit and the third ejection unit, and when the liquid is ejected from both nozzles of the second ejection unit and the third ejection unit. The fine vibration drive strength applied to the meniscus in the nozzle of the pressure chamber of the first injection unit is made different. Therefore, since the stirring effect with respect to the liquid in the pressure chamber of each injection unit is made uniform, there is an advantage that the liquid stirring state approaches uniformly.

In a further preferred aspect, when the first ejection unit does not eject the liquid in a control cycle, the control unit causes both the second ejection unit and the third ejection unit to perform the liquid in the control cycle. When not injecting, the first injecting unit is caused to perform the fine vibration driving with the third intensity exceeding the first intensity.
According to the above aspect, when the liquid is not ejected from the nozzles of both the second ejecting unit and the third ejecting unit, the first ejecting unit is caused to execute the micro-vibration driving with the third intensity. When the liquid is ejected from only one nozzle of the three ejection units, when the liquid is ejected from both nozzles, and when the liquid is not ejected from both nozzles, the meniscus in the nozzle of the first ejection unit The intensity of the fine vibration applied is made different. Therefore, since the stirring effect with respect to the pressure chamber of each injection part is made more uniform, there is an advantage that the liquid stirring state approaches more uniformly.

  In a further preferred aspect, the control unit stops the displacement of the pressure generating element of the first injection unit, instead of causing the first injection unit to execute the second intensity fine vibration drive. According to this aspect, when the liquid is not ejected from the nozzles of both the second ejection unit and the third ejection unit, the displacement of the pressure generating element of the first ejection unit is stopped. Excessive vibration of the ink is further suppressed. Therefore, the above-described effects such as reduction in power consumption, extension of the life of the pressure generating element, and uniformization of the liquid stirring state become more remarkable.

  In a preferred aspect of the present invention, the control unit determines whether or not the first ejecting unit ejects the liquid in the previous control period based on data designating contents for controlling the ejecting unit, When the liquid is not ejected, based on the determination of the determination unit and an injection determination unit that determines whether the injection unit closest to the first injection unit injects the liquid in the control cycle. And drive control means for changing the intensity of the micro-vibration drive executed by the first injection unit in the control cycle.

  The present invention can also be specified as a method of operating the liquid ejecting apparatus according to each of the above aspects (a method of controlling the liquid ejecting apparatus). The control method of the present invention includes a pressure chamber filled with a liquid, a nozzle communicating with the pressure chamber, and a pressure generating element that varies the pressure in the pressure chamber. In response, a plurality of ejection units capable of ejecting the liquid from the nozzle, and fine vibration driving that swings the liquid or the liquid level in the nozzle to such an extent that the liquid is not ejected from the nozzle for each control cycle. In the liquid ejecting apparatus including the control unit to be executed by the ejecting unit, when the first ejecting unit among the plurality of ejecting units does not eject the liquid in a control cycle, The intensity of the micro-vibration driving performed by the first ejection unit is changed in the control cycle according to whether the second ejection unit closest to the first ejection unit ejects the liquid in the control cycle. . Also in the above control method, the same operation and effect as the liquid ejecting apparatus of the present invention are realized.

It is a partial schematic diagram of a printing apparatus according to an embodiment of the present invention. 3 is a plan view of an ejection surface of a recording head. FIG. 3 is a configuration diagram of a recording head. 1 is a block diagram of an electrical configuration of a printing apparatus according to an embodiment. It is a wave form diagram of a drive signal. FIG. 2 is a block diagram of an electrical configuration of a recording head. 2 is a cross-sectional view of a recording head during ink ejection. It is a block diagram of the function which controls the intensity | strength of a fine vibration among control parts. It is an operation flow of control data generation. It is a figure which shows the vibration provided to a pressure chamber. It is a figure which shows the vibration provided to a pressure chamber. It is a figure which shows the vibration provided to a pressure chamber. It is a wave form diagram of a drive signal. It is a wave form diagram of a drive signal. FIG. 3 is an example of a plan view of an ejection surface of a recording head.

<A: Embodiment>
FIG. 1 is a partial schematic view of an ink jet printing apparatus 100 according to an embodiment of the present invention. The printing apparatus 100 is a liquid ejecting apparatus that ejects fine droplet-shaped ink onto the recording paper 200, and includes a carriage 12, a moving mechanism 14, a sheet conveying mechanism 16, and a cap 18.

  An ink cartridge 22 and a recording head 24 are mounted on the carriage 12. The ink cartridge 22 is a container that stores ink (liquid) ejected onto the recording paper 200. The recording head 24 functions as a liquid ejection unit that ejects ink stored in the ink cartridge 22 onto the recording paper 200. A configuration in which the ink cartridge 22 is fixed to a housing (not shown) of the printing apparatus 100 and ink is supplied to the recording head 24 can also be employed.

  The moving mechanism 14 in FIG. 1 reciprocates the carriage 12 along the guide shaft 122 in the main scanning direction (the width direction of the recording paper 200). The position of the carriage 12 is detected by a detector (not shown) such as a linear encoder and used for controlling the moving mechanism 14. The paper transport mechanism 16 moves the recording paper 200 in the sub-scanning direction in parallel with the reciprocation of the carriage 12. A desired image is recorded (printed) on the recording paper 200 by the recording head 24 ejecting ink onto the recording paper 200 during the reciprocation of the carriage 12.

  The moving mechanism 14 can move the recording head 24 to a position outside the range where the ejection surface faces the recording paper 200 (hereinafter referred to as “retraction position”). The cap 18 is disposed so as to face the ejection surface of the recording head 24 in the retracted position. The cap 18 seals the ejection surface of the recording head 24. A wiper (not shown) for wiping the discharge surface is disposed in the vicinity of the cap 18. The recording head 24 performs a flushing operation at the retracted position for discharging ink that is no longer suitable for ejection due to thickening or the like.

  FIG. 2 is a plan view of the ejection surface 26 of the recording head 24 that faces the recording paper 200. The X direction in FIG. 2 is the main scanning direction, and the Y direction is the sub scanning direction. As shown in FIG. 2, a plurality of nozzle groups G (GC, GM, GY, GK) are formed on the ejection surface 26 of the recording head 24. Each nozzle group G is a set of a plurality of nozzles 56 arranged in the Y direction at the same distance (inter-center distance) d. Ink droplets are ejected from each nozzle 56 of the nozzle group G. A plurality of nozzle groups G (GC, GM, GY, GK) respectively correspond to a plurality of different ink colors (cyan (C), magenta (M), yellow (Y), black (K)).

  FIG. 3 is a configuration diagram of the recording head 24 of the first embodiment. Specifically, the part (A) in FIG. 3 is a plan view of the recording head 24, and the part (B) in FIG. 3 is a cross-sectional view taken along the line IIIb-IIIb in the part (A). C) is a cross-sectional view in a section perpendicular to the line IIIb-IIIb in part (A). As shown in FIG. 3, the recording head 24 generally has a structure in which a flow path forming substrate 41, a nozzle forming substrate 42, an elastic film 43, an insulating film 44, a piezoelectric element 45, and a protective substrate 46 are laminated. .

  The flow path forming substrate 41 is a plate made of a metal plate such as stainless steel or a silicon single crystal substrate. As shown in part (A) and part (C) of FIG. 3, the flow path forming substrate 41 is provided with a plurality of long pressure chambers 50 arranged in parallel in the width direction (arrangement direction of the nozzles 56). The The pressure chambers 50 adjacent to each other are partitioned by a partition wall 58. Further, a communication portion 414 is formed in a region outside the longitudinal direction of each pressure chamber 50 in the flow path forming substrate 41. The communication portion 414 and each pressure chamber 50 communicate with each other via an ink supply path 416 formed for each pressure chamber 50. The ink supply path 416 is formed with a narrower width than the pressure chamber 50, and gives a certain flow path resistance to the ink flowing into the pressure chamber 50 from the communication portion 414.

As shown in part (B) and part (C) of FIG. 3, the nozzle forming substrate 42 is fixed to the surface (opening surface) of the flow path forming substrate 41 with, for example, an adhesive or a heat welding film. The nozzle forming substrate 42 is formed with a nozzle (through hole) 56 that communicates with the end of each pressure chamber 50 opposite to the ink supply path 416. On the other hand, an elastic film 43 is formed of, for example, silicon dioxide (SiO ₂ ) on the surface of the flow path forming substrate 41 opposite to the nozzle forming substrate 42. An insulating film 44 is formed of, for example, zirconium oxide (ZrO ₂ ) on the surface of the elastic film 43, and a piezoelectric element 45 is formed on the surface of the insulating film 44 for each pressure chamber 50.

  As shown in part (B) and part (C) of FIG. 3, each piezoelectric element 45 is a structure in which a lower electrode 451, a piezoelectric body 452, and an upper electrode 453 are stacked in this order from the insulating film 44 side. . One of the lower electrode 451 and the upper electrode 453 is a common electrode continuous over the plurality of pressure chambers 50, and the other of the lower electrode 451 and the upper electrode 453 and the piezoelectric body 452 are individually formed for each pressure chamber 50 (patterning). Is done. Which of the lower electrode 451 and the upper electrode 453 is used as a common electrode is appropriately determined according to, for example, the polarization direction of the piezoelectric body 452 and the convenience of wiring. A lead electrode 47 made of, for example, gold (Au) or the like is connected to the upper electrode 453 of each piezoelectric element 45. When an electric field is applied between the lower electrode 451 and the upper electrode 453 by supplying a drive signal via the lead electrode 47, each piezoelectric element 45 and the elastic film 43 are deformed (flexed deformation).

  As shown in part (B) of FIG. 3, a protective substrate 46 is fixed to the installation surface of each piezoelectric element 45 in the flow path forming substrate 41. A piezoelectric element holding portion 461 that accommodates each piezoelectric element 45 is formed in a region of the protective substrate 46 that faces each piezoelectric element 45. The piezoelectric element holding portion 461 is formed to a size that does not hinder the displacement of each piezoelectric element 45 and protects each piezoelectric element 45. A reservoir portion 462 that penetrates the protective substrate 46 is formed in a region corresponding to the communication portion 414 of the flow path forming substrate 41 in the protective substrate 46. The reservoir portion 462 is a long space along the direction in which the pressure chambers 50 are arranged. A space in which the communication portion 414 of the flow path forming substrate 41 and the reservoir portion 462 of the protective substrate 46 communicate with each other forms a reservoir 54 that functions as a common ink chamber of the pressure chambers 50.

  A through hole 463 that penetrates the protective substrate 46 in the thickness direction is formed in a region of the protective substrate 46 between the piezoelectric element holding portion 461 and the reservoir portion 462. The lower electrode 451 and the lead electrode 47 of the piezoelectric element 45 are exposed inside the through hole 463. On the surface of the protective substrate 46, a compliance substrate 48 in which a sealing film 481 and a fixing plate 482 are laminated is bonded. The sealing film 481 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide film), and seals the reservoir portion 462 of the protective substrate 46. The fixed plate 482 is made of a hard material (for example, stainless steel) such as metal. An opening 483 is formed in a region of the fixed plate 482 facing the reservoir 54 (reservoir portion 462).

  In the recording head 24 having the above-described configuration, the ink supplied from the ink cartridge 22 is filled in the space from the reservoir 54 to the nozzle 56 via each ink supply path 416 and each pressure chamber 50. When the piezoelectric element 45 and the elastic film 43 are deformed by supplying the drive signal, the pressure in the pressure chamber 50 varies. By controlling the pressure fluctuation in the pressure chamber 50 according to the drive signal, it is possible to execute an operation of ejecting ink in the pressure chamber 50 from the nozzle 56 (hereinafter referred to as “ejection driving”). That is, an element (hereinafter referred to as “ejection unit J”) including the piezoelectric element 45, the pressure chamber 50, and the nozzle 56 functions as an element that ejects ink. The nozzles 56 and the jetting parts J correspond one-to-one, and the jetting parts J are arranged in the sub-scanning direction (Y direction in FIG. 2) like the nozzles 56. The ejection unit J can also perform an operation (hereinafter referred to as “microvibration driving”) that swings the liquid level (meniscus) of the ink in the nozzle 56 to such an extent that the ink in the pressure chamber 50 is not ejected. is there.

  FIG. 4 is a block diagram of an electrical configuration of the printing apparatus 100. As illustrated in FIG. 4, the printing apparatus 100 includes a control device 102 and a print processing unit (print engine) 104. The control device 102 is an element that controls the entire printing apparatus 100, and includes a control unit 60, a storage unit 62, a drive signal generation unit 64, an external I / F (interface) 66, and an internal I / F 68. Print data DP indicating an image to be printed on the recording paper 200 is supplied from an external device (for example, a host computer) 300 to the external I / F 66, and the print processing unit 104 is connected to the internal I / F 68. The print processing unit 104 is an element that records an image on the recording paper 200 under the control of the control device 102, and includes the recording head 24, the moving mechanism 14, and the paper transport mechanism 16 described above.

  The storage unit 62 includes a ROM that stores a control program and the like, and a RAM that temporarily stores various data necessary for image printing. The control unit 60 comprehensively controls each element (for example, the print processing unit 104) of the printing apparatus 100 by executing the control program stored in the storage unit 62. Further, the control unit 60 performs ejection of ink in the pressure chamber 50 from the nozzle 56 and fine vibration driving (non-ejection) of the ink meniscus in the nozzle 56 based on the print data DP supplied from the external I / F 66. And control data DC for designating either the standby state (non-injection) in which the displacement of the piezoelectric element 45 is stopped is generated every printing cycle T. The fine vibrations indicated by the control data DC of the present embodiment include strong and weak vibrations. The intensity (power and amplitude) σ2 of the strong microvibration exceeds the intensity σ1 of the weak microvibration (σ2> σ1).

  The drive signal generator 64 generates a drive signal COM1 and a drive signal COM2. Each of the drive signal COM1 and the drive signal COM2 is a periodic signal that drives each piezoelectric element 45. As shown in FIG. 5, the injection pulse PD and the weak micro-vibration pulse PS1 are arranged in one cycle of the drive signal COM1, and the constant potential element PS0 and the strong micro-vibration pulse PS2 are arranged in one cycle of the drive signal COM2. And are arranged. One cycle of the drive signal COM1 and the drive signal COM2 is equal to the printing cycle T in which the control data DC is generated.

  Each of the weak micro-vibration pulse PS1 and the strong micro-vibration pulse PS2 is a drive pulse that slightly vibrates the meniscus in the nozzle 56 (executes micro-vibration driving). When a slight vibration is applied to the meniscus in the nozzle 56, the ink in the pressure chamber 50 is agitated. As shown in FIG. 5, each of the weak micro-vibration pulse PS1 and the strong micro-oscillation pulse PS2 changes in potential from a predetermined reference potential VREF to a potential (VH1 or VH2) on the lower side (the direction in which the pressure chamber 50 is depressurized). A section p1 for maintaining the potential (VH1 or VH2) at the end of the section p1, and a section p3 for returning to the reference potential VREF by changing the potential to the higher side (the direction in which the pressure chamber 50 is pressurized). It is a trapezoidal waveform including The potential VH2 of the section p2 of the strong vibration pulse PS2 is lower than the potential VH1 of the section p2 of the weak vibration pulse PS1, and the gradient of the section p1 and section p3 of the weak vibration pulse PS1 is the section p1 and section of the strong vibration pulse PS2. It is slow compared to the slope of p3. Note that the waveform of the weak micro-vibration pulse PS1 and the waveform of the strong micro-vibration pulse PS2 can be changed as appropriate.

  As shown in FIG. 5, the constant potential element PS0 includes a section p0 for maintaining a predetermined reference potential VREF. With the supply of the constant potential element PS0, the piezoelectric element 45 stops displacement and stands by. The ejection pulse PD deforms the piezoelectric element 45 and the elastic film 43 so as to pressurize the ink in the pressure chamber 50 so that a predetermined amount of ink is ejected from the nozzle 56 when supplied to the piezoelectric element 45. As shown in FIG. 5, the injection pulse PD has a section d1 in which the potential changes from the predetermined reference potential VREF to the lower side, a section d2 in which the potential changes from the reference potential VREF to the higher side, and a potential changes in the lower side. And a section d3 returning to the reference potential VREF. The waveform of the ejection pulse PD can be changed as appropriate.

  FIG. 6 is a schematic diagram of an electrical configuration of the recording head 24. As shown in FIG. 6, the recording head 24 includes a plurality of drive circuits 32 corresponding to different ejection portions J. The drive signal COM1 and the drive signal COM2 generated by the drive signal generator 64 are commonly supplied to the plurality of drive circuits 32 via the internal I / F 68. The control data DC generated by the control unit 60 is supplied to each drive circuit 32 via the internal I / F 68.

  Each drive circuit 32 selects a section corresponding to the control data DC supplied from the control unit 60 from the drive signal COM 1 or the drive signal COM 2 and supplies the selected section to the piezoelectric element 45. Specifically, when the control data DC indicates a standby state, the drive circuit 32 selects the constant potential element PS0 of the drive signal COM2 and supplies it to the piezoelectric element 45. When the constant potential element PS is supplied, the piezoelectric element 45 stands by without executing ink ejection (ejection driving) or micro-vibration driving, so that the ink in the pressure chamber 50 is not agitated. When the control data DC instructs the application of weak microvibration, the drive circuit 32 selects the weak microvibration pulse PS1 of the drive signal COM1 and supplies it to the piezoelectric element 45. Therefore, a slight vibration is applied to the meniscus in the nozzle 56, and the ink in the pressure chamber 50 is stirred without being ejected. When the control data DC instructs the application of strong vibration, the drive circuit 32 selects the strong vibration pulse PS2 of the drive signal COM2 and supplies it to the piezoelectric element 45. Therefore, strong vibration is applied to the meniscus in the nozzle 56, and the ink in the pressure chamber 50 is agitated without being ejected. Since the intensity σ 2 of the strong vibration exceeds the intensity σ 1 of the weak vibration, the ink in the pressure chamber 50 to which the strong vibration is applied to the meniscus in the nozzle 56 is applied to the meniscus in the nozzle 56. The ink in the pressure chamber 50 is sufficiently stirred. When the control data DC instructs ink ejection (ejection driving), the drive circuit 32 selects the ejection pulse PD of the drive signal COM1 and supplies it to the piezoelectric element 45. Therefore, the ink in the pressure chamber 50 is ejected from the nozzle 56.

  FIG. 7 is a cross-sectional view (a cross section perpendicular to the sub-scanning direction) of a part of the recording head 24 when ink is ejected by supplying the ejection pulse PD. Each pressure chamber 50 is partitioned by a partition wall 58. The injection part J of interest is referred to as a first injection part J1, and the injection part J corresponding to one of the pressure chambers 50 sharing the partition wall 58 with the pressure chamber 50 of the first injection part J1 is referred to as the second injection part J2. The injection part J located on the opposite side of the second injection part J2 with respect to the first injection part J1 is referred to as a third injection part J3. As described in the explanation of FIG. 3, since each injection part J is arranged in the sub-scanning direction, each of the second injection part J2 and the third injection part J3 is an injection closest to the first injection part J1. It is understood that this is part J.

  When the piezoelectric element 45 and the elastic film 43 of the second ejection part J2 are deformed by the supply of the ejection pulse PD, the ink in the pressure chamber 50 of the second ejection part J2 is pressurized, and the displacement of the piezoelectric element 45 and the elastic film 43 and The partition wall 58 is deformed by the pressure F acting from the ink in the pressure chamber 50. Therefore, the vibration in the ejection of the ink by the second ejection unit J2 propagates through the partition wall 58 to the ink in the pressure chamber 50 of the first ejection unit J1. Then, the ink in the pressure chamber 50 of the first ejection part J1 is agitated by the vibration propagating from the second ejection part J2. Similarly, when ink is ejected from the third ejecting portion J3, vibration during ink ejection by the third ejecting portion J3 propagates to the ink in the pressure chamber 50 of the first ejecting portion J1 via the partition wall 58. To do. Therefore, in the present embodiment, the intensity of the fine vibration applied to the ink meniscus in the nozzle 56 of the first ejection part J1 is such that the ink ejection from the nozzles 56 of the second ejection part J2 and the third ejection part J3 ( Control data DC is generated so as to change according to the presence or absence of (injection drive).

  FIG. 8 is a block diagram of a function of controlling the intensity of fine vibration applied to the ink meniscus in the nozzle 56 of the first ejection unit J1 in the control unit 60. As shown in FIG. 8, the control unit 60 functions as an injection determination unit 72 and a drive control unit 74. Each element in FIG. 8 is realized by executing a control program stored in the storage unit 62.

  The ejection determination unit 72 determines whether or not to eject ink from the nozzles 56 of the first ejection unit J1 based on the print data DP supplied from the external device 300 for each printing cycle T. When ink is not ejected from the nozzle 56 of the first ejection part J1, the ejection determination part 72 further has the nozzles of the second ejection part J2 and the third ejection part J3 closest to the first ejection part J1 in the printing cycle T. 56, it is determined whether or not to eject ink. Based on the determination of the injection determination unit 72, the drive control unit 74 generates control data DC that causes the first injection unit J1 to execute any one of the injection drive, the fine vibration drive, and the standby state in the printing cycle T.

  Specifically, the control unit 60 generates control data DC according to the operation flow shown in FIG. The operation of FIG. 9 is executed every printing cycle T. The same operation is performed for each of the plurality of nozzle groups G. When the operation of FIG. 9 is started, the control unit 60 selects the injection unit J corresponding to the first nozzle 56 among the N nozzles 56 included in the nozzle group G as the first injection unit J1 (control). It is selected as the injection unit J) that generates the data DC (S101, S102).

  The control unit 60 (ejection determination unit 72) refers to the print data DP to determine whether or not the first ejection unit J1 needs to eject ink from the nozzles 56 in the printing cycle T (S103). . When it is determined that the first ejection unit J1 needs to eject ink (S103: YES), the control unit 60 (drive control unit 74) ejects ink to the first ejection unit J1 (that is, to the piezoelectric element 45). Control data DC for instructing the supply of the injection pulse PD) (S104).

  On the other hand, when the first ejection unit J1 determines that it is not necessary to eject ink from the nozzle 56 (S103: NO), the control unit 60 (ejection determination unit 72) refers to the print data DP and performs the first ejection. It is determined whether or not the two ejection parts J (second ejection part J2 and third ejection part J3) adjacent to the part J1 need to eject ink from the nozzle 56 (S105). When the first ejection unit J1 is located at the end of the nozzle group G, if one of the second ejection unit J2 and the third ejection unit J3 is treated as an ejection unit J that does not eject ink, a determination is made. Good.

  When it is determined that neither the second ejection unit J2 nor the third ejection unit J3 needs to eject ink (S105: both are not ejected), the control unit 60 (drive control unit 74) is as shown in FIG. Then, control data DC for instructing the application of strong vibration to the meniscus in the nozzle 56 of the first injection section J1 (that is, supply of the strong vibration pulse PS2 to the piezoelectric element 45) is generated (S106). That is, as shown in FIG. 10, since vibration does not propagate from the second ejection part J2 and the third ejection part J3 to the ink in the pressure chamber 50 of the first ejection part J1, the nozzle of the first ejection part J1 The ink in the pressure chamber 50 is sufficiently stirred by applying strong vibrations to the meniscus in 56.

  When it is determined that one of the second ejection unit J2 and the third ejection unit J3 needs to eject ink (S105: one is ejected), the control unit 60 (drive control unit 74) is shown in FIG. As described above, the control data DC for instructing the application of weak vibrations to the meniscus in the nozzle 56 of the first injection unit J1 (that is, supply of the weak vibration pulse PS1 to the piezoelectric element 45) is generated (S107). That is, the vibration when ink is ejected from the nozzle 56 of one of the second ejection part J2 and the third ejection part J3 (in the example shown in FIG. 11, the second ejection part J2) passes through the partition wall 58. Since the ink in the pressure chamber 50 is agitated by propagating to the ink in the pressure chamber 50 of the first ejection part J1, it is applied from the second ejection part J2 and the third ejection part J3 as shown in FIG. Compared to the case where there is no vibration, the ink in the pressure chamber 50 is sufficiently stirred even if the intensity of the fine vibration applied to the meniscus in the nozzle 56 is weakened (that is, even by applying the weak vibration).

  When it is determined that both the second ejection unit J2 and the third ejection unit J3 need to eject ink (S105: both eject), the control unit 60 (drive control unit 74), as shown in FIG. Then, control data DC for instructing the first injection unit J1 to be in a standby state (that is, supply of the constant potential element PS0 to the piezoelectric element 45) is generated (S108). In other words, as shown in FIG. 12, the vibrations of the ink ejected by both the second ejecting part J2 and the third ejecting part J3 propagate to the ink in the pressure chamber 50 of the first ejecting part J1 through the partition wall 58. As a result, the ink in the pressure chamber 50 is agitated, so that either one of the second ejecting part J2 and the third ejecting part J3 is ejected. Even if the intensity of the fine vibration applied to the meniscus is further reduced (that is, even when the displacement of the piezoelectric element 45 is stopped), the ink in the pressure chamber 50 is sufficiently stirred.

  When the generation of the control data DC for the first injection unit J1 is completed (S104 to S108), the control unit 60 determines whether the current first injection unit J1 is the last (Nth) injection unit J in the nozzle group G. It is determined whether or not (S109). If it is determined that the last (Nth) injection unit J in the nozzle group G is selected (S109: YES), control data for all of the injection units J corresponding to the nozzles 56 in the nozzle group G Since DC has been generated, the generation of control data DC for the printing cycle T is terminated. On the other hand, when it is determined that it is not the last (Nth) injection unit J in the nozzle group G (S109: NO), since the injection unit J for which the control data DC has not yet been generated remains, the control unit 60 The next injection part J is selected as the first injection part J1 (S110, S102), and the above analysis operation is repeated.

  With the above operation flow, control data DC indicating the intensity of vibration to be applied is generated for each ejection part J (pressure chamber 50) for a certain printing cycle T. Then, the above operation flow is executed for all the printing cycles T necessary for printing by the print data DP, whereby the ink jetting (jetting driving) of the jetting part J and the meniscus in the nozzle 56 of the jetting part J are performed. Control data DC that designates either micro-vibration driving (weak micro-vibration driving or strong micro-vibration driving) and a standby state in which neither ink ejection nor micro-vibration is applied is printed every printing cycle T and every ejection unit J. Is generated.

  According to the embodiment described above, whether or not ink is ejected from the nozzle 56 of the jetting part J having the closest strength to the meniscus in the nozzle 56 of each jetting part J within the printing cycle T is shown. Therefore, it is possible to suppress the application of excessive vibration to the ink in each pressure chamber 50 as compared with the configuration in which the presence or absence of ink ejection from the nozzle 56 of the nearest ejection section J is not considered. Is possible. Therefore, it is possible to reduce the power consumption required for applying the minute vibration. In addition, since the voltage applied to the piezoelectric element 45 is reduced, the operating life of the piezoelectric element 45 can be extended.

  The ink component thickened in the vicinity of the nozzle 56 is diffused into the pressure chamber 50 by applying fine vibration to the meniscus in the nozzle 56. Therefore, the higher the intensity of the micro-vibration applied to the meniscus in the nozzle 56, the greater the injection amount for discharging the thickening component from the pressure chamber 50 by flushing. According to the above-described embodiment, since the application of excessive fine vibration (that is, the diffusion of the thickening component) to the meniscus in the nozzle 56 is suppressed, there is an advantage that the amount of ink ejected by flushing can be reduced. is there.

  Further, ink is ejected from only one of the nozzles 56 of the second ejection part J2 and the third ejection part J3, and ink is ejected from both the nozzles 56 of the second ejection part J2 and the third ejection part J3. And the case where no ink is ejected from the nozzles 56 of both the second ejection part J2 and the third ejection part J3, the intensity of fine vibration applied to the meniscus in the nozzle 56 of the first ejection part J1 is different. . Accordingly, ink is ejected from only one of the nozzles 56 of the second ejecting part J2 and the third ejecting part J3, and ink is ejected from both the nozzles 56 of the second ejecting part J2 and the third ejecting part J3. And the case where ink is not ejected from the nozzles 56 of both the second ejecting part J2 and the third ejecting part J3, the advantage that the stirring effect on the ink in the pressure chamber 50 of the first ejecting part J1 is made uniform. There is.

<B: Modification>
The above embodiment can be variously modified. Specific modifications are exemplified below. Two or more aspects arbitrarily selected from the following examples can be appropriately combined as long as they do not contradict each other.
(1) Modification 1

  In the above embodiment, in the printing cycle T, when the ink is not ejected from the nozzle 56 of the first ejecting section J1, the two ejecting sections J (the second ejecting section J2 and the third ejecting section) that are closest to the first ejecting section J1. Depending on whether or not the ink is ejected from the nozzle 56 of the part J3), the intensity of the fine vibration to the meniscus in the nozzle 56 of the first ejection part J1 is changed. However, for example, in the configuration in which the distance between the ejection units J is different and thus there is one ejection unit J closest to each ejection unit J, one ejection unit closest to the ejection unit J that does not eject ink from the nozzle 56. Depending on whether or not the ink is ejected from the nozzle 56 of J, the intensity of the fine vibration to the meniscus in the nozzle 56 of the ejection section J that does not eject ink may be changed.

(2) Modification 2
In the above embodiment, a plurality of drive signals (COM1, COM2) are supplied to the recording head 24. However, a configuration in which only one drive signal is used to drive each piezoelectric element 45 or three or more drive signals are used. A configuration used for driving each piezoelectric element 45 may also be employed. In the configuration using one system drive signal, for example, as shown in FIG. 13, a drive signal COM in which a constant potential element PS0, a weak micro-vibration pulse PS1, a strong micro-oscillation pulse PS2, and an injection pulse PD are arranged in time series. Is supplied to the recording head 24.

  The pulse height and waveform of each pulse of the drive signal are arbitrary. For example, it is not limited to the trapezoidal pulse illustrated in FIG. 5, and for example, a rectangular pulse can be adopted. The waveform of the fine vibration pulses (PS1, PS2) of the drive signal is limited to the example shown in FIG. 5 as long as the ink (meniscus) is swung to such an extent that the ink in the pressure chamber 50 is not ejected from the nozzle 56. It can be arbitrarily changed without any change.

  Further, as shown in FIG. 14, an extremely weak vibration pulse PS3 may be used instead of the constant potential element PS0 of the drive signal. The potential VH3 in the interval p2 of the extremely weak vibration pulse PS3 exceeds the potential VH2 in the interval p2 of the weak oscillation pulse PS1, and the gradient of the interval p1 of the extremely weak oscillation pulse PS3 and the interval p3 is the interval p1 of the weak oscillation pulse PS1. And is slower than the slope of the interval p3. Therefore, the intensity σ3 of the extremely weak vibration caused by the extremely weak vibration pulse PS3 is lower than the intensity σ1 of the weak vibration.

  That is, since two injection parts J arranged on both sides of a certain injection part J can take three injection patterns (both are injections, one is injections, and both are non-injections), they correspond to these three injection patterns. The waveform of the drive signal is arbitrary as long as the waveform can execute micro-vibration driving with three different levels of intensity. Further, the strength of the fine vibration drive includes zero strength, that is, stoppage of the displacement of the piezoelectric element 45.

(3) Modification 3
In the above embodiment, the plurality of nozzles 56 in the nozzle group G are arranged in a straight line, but the plurality of nozzles 56 may be arranged in a staggered manner. That is, as shown in FIG. 15, each nozzle group G may include a first nozzle row L <b> 1 and a second nozzle row L <b> 2 each including a plurality of nozzles 56. Specifically, each of the first nozzle row L1 and the second nozzle row L2 is a set of a plurality of nozzles 56 arranged in the Y direction with a distance (inter-center distance) d from each other. A straight line in the Y direction (center line of the first nozzle row L1) a1 connecting the centers of the nozzles 56 of the first nozzle row L1 and a straight line in the Y direction connecting the centers of the nozzles 56 of the second nozzle row L2 ( The center line a2) of the second nozzle row L2 extends in parallel with a distance m from each other. Further, the positions in the Y direction of the respective nozzles 56 of the first nozzle array L1 and the respective nozzles 56 of the second nozzle array L2 are different. Specifically, the position in the Y direction of each nozzle 56 in the first nozzle row L1 and the position in the Y direction of each nozzle 56 in the second nozzle row L2 are the positions of the nozzles 56 adjacent to each other in the Y direction in each nozzle row. The distances are shifted from each other in the Y direction by half (d / 2) of the distance d between the centers.

When a plurality of nozzles 56 are arranged in a staggered pattern, for a certain nozzle 56, the distance d from the nearest nozzle 56 in the same nozzle row and the adjacent nozzle rows (the first nozzle row L1 and the second nozzle row L2) Since the distance (m ² + (d / 2) ² ) ^1/2 with the nearest nozzle 56 in the adjacent nozzles 56 can be arbitrarily set, the injection unit J corresponding to a certain nozzle 56 is the most The near ejection part J may be the ejection part J corresponding to the nearest nozzle 56 in the same nozzle row, or may be the ejection part J corresponding to the nearest nozzle 56 in the adjacent nozzle row. Of course it is understood.

(4) Modification 4
The configuration of the element (pressure generating element) that changes the pressure in the pressure chamber 50 is not limited to the above examples. For example, a vibrating body such as an electrostatic actuator can be used. Further, the pressure generating element of the present invention is not limited to an element that imparts mechanical vibration to the pressure chamber 50. For example, a heat generating element (heater) that changes the pressure in the pressure chamber 50 by generating bubbles by heating the pressure chamber 50 can be used as the pressure generating element. In other words, the pressure generating element of the present invention is included as an element for changing the pressure in the pressure chamber 50, and the method for changing the pressure (piezo method / thermal method) and the configuration are not limited.

(5) Modification 5
The printing apparatus 100 of the above embodiment can be employed in various devices such as a plotter, a facsimile machine, and a copier. However, the application of the liquid ejecting apparatus of the present invention is not limited to image printing. For example, a liquid ejecting apparatus that ejects a solution of each color material is used as a manufacturing apparatus that forms a color filter of a liquid crystal display device. In addition, a liquid ejecting apparatus that ejects a liquid conductive material is used as an electrode manufacturing apparatus that forms electrodes of a display device such as an organic EL (Electroluminescence) display device or a field emission display (FED). The A liquid ejecting apparatus that ejects a bioorganic solution is used as a chip manufacturing apparatus that manufactures biochemical elements (biochips, microarrays). Therefore, what is ejected from the liquid ejecting apparatus is an arbitrary liquid that causes a change in physical properties (such as thickening or sedimentation) that can be improved by the application of fine vibrations.

  Further, in the above embodiment, the serial type printing apparatus 100 in which the carriage 12 on which the recording head 24 is mounted moves in the main scanning direction is illustrated, but a plurality of nozzles are arranged over the entire area in the width direction of the recording paper. The present invention can also be applied to a printing apparatus using a line-type recording head that is elongated in the main scanning direction.

DESCRIPTION OF SYMBOLS 100 ... Printing apparatus, 12 ... Carriage, 14 ... Movement mechanism, 16 ... Paper conveyance mechanism, 18 ... Cap, 22 ... Ink cartridge, 24 ... Recording head, 26 ... Discharge surface, 32 ... Drive circuit 42... Nozzle forming substrate 43. Elastic film 44. Insulating film 45. Piezoelectric element 50. Pressure chamber 54. Reservoir 56 56 Nozzle 58. ...... Control unit, 72 ...... Injection determination unit, 74 …… Drive control unit, 102 ...... Control device, 104 ...... Print processing unit, 60 ...... Control unit, 62 ...... Storage unit, 64 ...... Drive signal generation , 66 ... External I / F, 68 ... Internal I / F, 200 ... Recording paper, COM1, COM2 ... Drive signal, G ... Nozzle group, J ... Injection unit, PD ... Injection pulse, PS1, PS2, PS3: Slight vibration pulse, PS0: Constant potential element, T: Mark Character cycle.

Claims (6)

Each including a pressure chamber filled with a liquid, a nozzle communicating with the pressure chamber, and a pressure generating element that varies the pressure in the pressure chamber; A plurality of injection units that can be injected from,
A control unit that controls the pressure generating element to cause the ejection unit to execute fine vibration driving that causes the ejection of the liquid or the liquid level in the nozzle so as not to eject the liquid from the nozzle. A liquid ejecting apparatus comprising:
The control unit includes a second injection unit that is closest to the first injection unit among the plurality of injection units when the first injection unit of the plurality of injection units does not inject the liquid in a control cycle. A liquid ejecting apparatus that changes the intensity of micro-vibration driving performed by the first ejection unit in the control cycle according to whether or not the liquid is ejected in the control cycle. The plurality of injection units include a third injection unit that is located on the opposite side of the second injection unit with respect to the first injection unit and is closest to the first injection unit,
The control unit, when the first ejection unit does not eject the liquid in the control cycle, when only one of the second ejection unit and the third ejection unit ejects the liquid in the control cycle, When the first ejecting unit is caused to perform micro-vibration driving of the first intensity and both the second ejecting part and the third ejecting part eject the liquid in the control cycle, the first intensity is less than the first intensity. The liquid ejecting apparatus according to claim 1, wherein the first ejecting unit is configured to perform fine vibration driving with two strengths. When the first ejection unit does not eject the liquid in a control cycle, the control unit is configured such that when both the second ejection unit and the third ejection unit do not eject the liquid in the control cycle, The liquid ejecting apparatus according to claim 2, wherein the first ejecting unit is caused to execute micro-vibration driving with a third strength exceeding the first strength. 4. The control unit according to claim 2, wherein the control unit stops the displacement of the pressure generating element of the first injection unit in place of causing the first injection unit to execute the second intensity micro-vibration driving. 5. Liquid ejector. The controller is
It is determined whether or not the first ejecting unit ejects the liquid in the previous control cycle based on data designating contents for controlling the ejecting unit, and when the liquid is not ejected, the first ejecting is performed. An injection determining means for determining whether or not the injection unit closest to the unit injects the liquid in the control cycle;
5. The liquid according to claim 1, further comprising: a drive control unit that changes the intensity of the micro-vibration driving performed by the first injection unit in the control cycle based on the determination of the determination unit. Injection device. Each including a pressure chamber filled with a liquid, a nozzle communicating with the pressure chamber, and a pressure generating element that varies the pressure in the pressure chamber; A plurality of injection units that can be injected from,
In a liquid ejecting apparatus comprising: a control unit that causes the ejecting unit to perform micro-vibration driving for ejecting the liquid or swinging the liquid level in the nozzle to such an extent that the liquid is not ejected from the nozzle.
When the first injection unit among the plurality of injection units does not inject the liquid in the control cycle, the second injection unit closest to the first injection unit among the plurality of injection units is in the control cycle. A control method for a liquid ejecting apparatus, wherein the intensity of micro-vibration driving performed by the first ejecting unit is changed in the control cycle according to whether or not the liquid is ejected.

Images