JP2018199315A - Liquid injection device and driving method for the same - Google Patents

Abstract

A liquid ejecting apparatus capable of ensuring high driving stability over a long period of time and a driving method thereof are provided. The drive signal includes a first period for changing the volume of the pressure generation chamber, a vibration damping adjustment element P04 for maintaining the volume of the pressure generation chamber after the first period, and after the vibration damping adjustment element P04. A damping element P05 that changes the volume of the pressure generation chamber to suppress residual vibration in the pressure generation chamber, and the control unit outputs drive signals having different lengths of the damping adjustment element P04 to the liquid ejecting head. After the drive signal is supplied, the amplitude of the residual vibration in the pressure generating chamber is detected, and based on the length of the vibration control adjustment element P04 of the drive signal whose amplitude is equal to or less than a predetermined value, the vibration suppression adjustment element P04 The appropriate length is calculated, and the drive signal is updated to the drive signal including the vibration suppression adjustment element P04 having the appropriate length. [Selection] Figure 4

Description

  The present invention relates to a liquid ejecting apparatus and a driving method thereof.

  Conventionally, there is an ink jet recording apparatus as a typical example of a liquid ejecting apparatus. The ink jet recording apparatus is equipped with an ink jet recording head that ejects ink as a liquid.

  Inkjet recording heads generally include a nozzle opening, a pressure generation chamber communicating with the nozzle opening, and pressure generation means provided on one side of the substrate on which the pressure generation chamber is formed. The volume of the pressure generating chamber is contracted by the displacement of the pressure generating means according to the drive signal to pressurize the liquid, and the liquid is discharged from the nozzle opening. Since pressure vibration may remain in the pressure generating chamber after ink ejection, the drive signal includes an element for suppressing the residual vibration.

  In this type of recording apparatus, if the natural vibration period is deviated due to a dimensional error at the time of manufacture, the driving stability varies even though the driving signal is the same. Therefore, for the assembled ink jet recording head, the period of the back electromotive voltage signal from the piezoelectric member based on the residual vibration is measured as the natural vibration period of the ink in the pressure generating chamber, and the natural vibration period is as designed. It has been proposed to classify a rank, a rank shorter than the design value, and a rank longer than the design value, and to set drive signals having different waveforms for each rank (see, for example, Patent Document 1).

JP 2004-351703 A

  However, in recent years, it has been desired that high driving stability can be ensured due to an increase in demand for higher performance of the liquid ejecting apparatus. Even if a different drive signal is set for each rank of the natural vibration period measured after assembly as in Patent Document 1, due to deterioration of the configuration, change in ink characteristics, change in ink type, etc. due to use of the liquid ejecting apparatus It is assumed that the natural vibration period is deviated. In this case, residual vibration in the pressure generation chamber cannot be effectively suppressed, and there is a possibility that sufficient drive stability cannot be ensured, such as occurrence of defective ejection of missing dots.

  Such a problem exists not only in the ink jet recording apparatus but also in a liquid ejecting apparatus that ejects liquid other than ink.

  SUMMARY An advantage of some aspects of the invention is that it provides a liquid ejecting apparatus and a driving method thereof that can ensure high driving stability over a long period of time.

  An aspect of the present invention that solves the above problems includes a nozzle opening through which liquid is discharged, a pressure generation chamber that communicates with the nozzle opening, and pressure generation that is displaced according to a drive signal to change the volume of the pressure generation chamber. And a control unit that generates the driving signal and supplies the driving signal to the liquid ejecting head, wherein the driving signal changes the volume of the pressure generating chamber; A damping control element that maintains the volume of the pressure generation chamber after the first period, and a residual vibration in the pressure generation chamber is suppressed by changing the volume of the pressure generation chamber after the damping control element. The control unit supplies drive signals having different lengths of the vibration suppression adjustment elements to the liquid ejecting head, and after supplying the drive signals, Detect residual vibration amplitude And calculating the appropriate length of the vibration suppression adjustment element based on the length of the vibration suppression adjustment element of the drive signal with the amplitude equal to or less than a predetermined value, and driving including the vibration suppression adjustment element of the appropriate length. In the liquid ejecting apparatus, the driving signal is updated to a signal.

  According to this aspect, since the drive signal including the vibration suppression adjustment element having the appropriate length is updated in a timely manner, not only when the liquid ejecting apparatus is shipped, the deterioration of the configuration accompanying the use, the change in the ink characteristics, and the change in the ink type For example, the pressure generating means can be driven by a drive signal in which the length of the damping control element is optimized, and the residual vibration in the pressure generating chamber can be effectively suppressed over a long period of time. As a result, ink ejection defects can be effectively suppressed over a long period of time, and high drive stability can be ensured over a long period of time.

  Here, it is preferable that the control unit calculates the appropriate length every time the operating time of the liquid ejecting apparatus passes a predetermined time. According to this, during operation of the apparatus, the length of the vibration damping adjustment element can be regularly optimized to update the drive signal. Therefore, high driving stability can be reliably ensured over a long period of time.

  The control unit may detect the amplitude corresponding to the length of the vibration suppression adjustment element and detect at least three sets of the vibration suppression adjustment elements with different lengths, and calculate the appropriate length. preferable. According to this, the length of the vibration damping adjustment element can be optimized using at least three sets of parameters with different lengths of the vibration damping adjustment element, and the accuracy of the calculated appropriate length increases. Therefore, high driving stability can be ensured more reliably over a long period of time.

  Further, the control unit predicts a relationship of the amplitude to the length of the vibration suppression adjustment element based on the length of the vibration suppression adjustment element and the amplitude according to the length of the vibration suppression adjustment element. In addition, it is preferable to calculate the length of the vibration damping adjustment element that minimizes the amplitude based on the predicted relationship as the appropriate length. According to this, the length of the vibration damping adjustment element can be optimized so that the residual vibration can be most suppressed. Therefore, high driving stability can be ensured extremely reliably over a long period of time.

  Another aspect of the present invention that solves the above problems includes a nozzle opening through which liquid is discharged, a pressure generation chamber communicating with the nozzle opening, and a pressure that changes the volume of the pressure generation chamber by being displaced according to a drive signal. A liquid ejecting head having a generating unit; and a control unit that generates the drive signal and supplies the drive signal to the liquid ejecting head, wherein the drive signal generates the pressure A first period for changing the volume of the chamber; a damping control element for maintaining the volume of the pressure generating chamber after the first period; and a volume of the pressure generating chamber after the damping control element. A damping element that suppresses residual vibration in the pressure generating chamber, and supplies drive signals having different lengths of the damping adjustment element to the pressure generating means, and the length of the damping adjustment element. Different drive signals are supplied Each time, the amplitude of the residual vibration in the pressure generating chamber is detected, the appropriate length of the vibration damping adjustment element at which the amplitude is equal to or less than a predetermined value is calculated, and the length of the vibration damping adjustment element is equal to the appropriate length. The driving signal is updated so that the driving method of the liquid ejecting apparatus is characterized.

  According to this aspect, since the drive signal including the vibration suppression adjustment element having the appropriate length is updated in a timely manner, not only when the liquid ejecting apparatus is shipped, the deterioration of the configuration accompanying the use, the change in the ink characteristics, and the change in the ink type For example, the pressure generating means can be driven by a drive signal in which the length of the damping control element is optimized, and the residual vibration in the pressure generating chamber can be effectively suppressed over a long period of time. As a result, ink ejection defects can be effectively suppressed over a long period of time, and high drive stability can be ensured over a long period of time.

  Still another aspect of the present invention that solves the above problems includes a nozzle opening through which liquid is discharged, a pressure generation chamber that communicates with the nozzle opening, and a volume of the liquid in the pressure generation chamber that is displaced according to a drive signal. And a control unit that generates the driving signal and supplies the driving signal to the liquid ejecting head, and the driving signal changes the volume of the pressure generating chamber. A first period of time, a damping control element that maintains the volume of the pressure generation chamber after the first period, and a volume of the pressure generation chamber after the damping control element is expanded to expand the pressure generation chamber A damping element that suppresses residual vibration of the liquid jet head, and the control unit supplies drive signals having different lengths of the damping adjustment element to the liquid ejecting head, and the supply of the drive signal causes the liquid ejection head to From the liquid jet head Obtaining a range of the length of the vibration damping adjustment element in which the degree of detection of ejection failure of the body is a predetermined value or less, calculating an appropriate length of the vibration damping adjustment element based on a value within the range, In the liquid ejecting apparatus, the driving signal is updated to a driving signal including a length damping adjustment element.

  According to this aspect, since the drive signal including the vibration suppression adjustment element having the appropriate length is updated in a timely manner, not only when the liquid ejecting apparatus is shipped, the deterioration of the configuration accompanying the use, the change in the ink characteristics, and the change in the ink type For example, it is possible to drive the pressure generating means with a drive signal that optimizes the length of the vibration damping adjustment element, effectively suppressing ink ejection defects caused by residual vibration in the pressure generating chamber over a long period of time. it can. Therefore, high driving stability can be ensured over a long period of time.

  According to still another aspect of the present invention for solving the above problem, a nozzle opening from which liquid is discharged, a pressure generation chamber communicating with the nozzle opening, and a volume of the pressure generation chamber are changed by displacement according to a drive signal. A liquid ejecting apparatus comprising: a liquid ejecting head having pressure generating means; and a control unit that generates the drive signal and supplies the drive signal to the liquid ejecting head, wherein the drive signal is the pressure A first period in which the volume of the generation chamber is changed; a vibration suppression adjustment element that maintains the volume of the pressure generation chamber after the first period; and a volume of the pressure generation chamber after the vibration suppression adjustment element A damping element for suppressing residual vibration in the pressure generating chamber, and supplying drive signals having different lengths of the damping adjustment elements to the pressure generating means, Said liquid jet by supply The damping of the appropriate length calculated based on a value within the range of the length of the damping adjustment element that detects the ejection failure of the liquid from the lid and the degree of detection of the ejection failure is a predetermined value or less In the driving method of the liquid ejecting apparatus, the driving signal is updated to a driving signal including an element.

  According to this aspect, since the drive signal including the vibration suppression adjustment element having the appropriate length is updated in a timely manner, not only when the liquid ejecting apparatus is shipped, the deterioration of the configuration accompanying the use, the change in the ink characteristics, and the change in the ink type For example, it is possible to drive the pressure generating means with a drive signal that optimizes the length of the vibration damping adjustment element, effectively suppressing ink ejection defects caused by residual vibration in the pressure generating chamber over a long period of time. it can. Therefore, high driving stability can be ensured over a long period of time.

1 is a diagram illustrating a schematic configuration of an ink jet recording apparatus according to Embodiment 1. FIG. FIG. 3 is an exploded perspective view illustrating a configuration example of the ink jet recording head according to the first embodiment. FIG. 3 is a cross-sectional view illustrating a configuration example of the ink jet recording head according to the first embodiment. FIG. 3 is a diagram illustrating an example of a drive signal to the ink jet recording head according to the first embodiment. The figure for demonstrating the residual vibration in a pressure generation chamber. FIG. 2 is a block diagram illustrating a configuration example related to a control system according to the first embodiment. FIG. 2 is a block diagram illustrating a configuration example related to a control system according to the first embodiment. FIG. 5 is a diagram illustrating an example of drive signals in which the lengths of vibration damping adjustment elements according to the first embodiment are different from each other. FIG. 4 is a diagram illustrating an example of a residual vibration amplitude detection method according to the first embodiment. FIG. 3 is a flowchart of a method for driving the ink jet recording apparatus according to the first embodiment. FIG. 5 is a block diagram illustrating a configuration example related to a control system according to a second embodiment. FIG. 5 is a block diagram illustrating a configuration example related to a control system according to a second embodiment. FIG. 9 is a diagram for explaining a method for calculating an appropriate length of a vibration suppression adjustment element according to the second embodiment. FIG. 5 is a flowchart of a method for driving an ink jet recording apparatus according to a second embodiment. FIG. 6 is a diagram illustrating an example of a drive signal applicable in the present invention. FIG. 6 is a diagram illustrating an example of a drive signal applicable in the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a diagram illustrating a schematic configuration of an ink jet recording apparatus which is an example of a liquid ejecting apparatus according to the present embodiment.

  An ink jet recording apparatus I (hereinafter abbreviated as “recording apparatus I”) includes an ink jet recording head 1 (hereinafter abbreviated as “recording head 1”) that ejects ink, and a control device 200 that controls the recording apparatus I. It is comprised.

  The recording head 1 is provided on a carriage 3 to which an ink cartridge 2 can be attached and detached, and the carriage 3 is configured to be movable in the axial direction along the carriage shaft 5 of the apparatus main body 4. When the drive motor 6 is driven, a driving force is transmitted to the carriage 3 through a plurality of gears (not shown) and a timing belt 7, and the carriage 3 reciprocates along the carriage shaft 5.

  The apparatus main body 4 is provided with a conveyance roller 8, and is configured such that a medium such as a recording sheet S on which ink is ejected is conveyed by the conveyance roller 8. That is, in the recording apparatus I, the carriage 3 is reciprocated along the carriage shaft 5 while conveying the recording sheet S, and ink is ejected from the recording head 1. The means for transporting the recording sheet S is not limited to the transport roller 8 and may be a belt, a drum, or the like.

  In the present specification, the conveyance direction of the recording sheet S is the first direction X, the direction along the carriage shaft 5 is the second direction Y, and the height intersecting both the first direction X and the second direction Y. The direction is referred to as a third direction Z. In the present specification, the first direction X, the second direction Y, and the third direction Z are orthogonal to each other, but the arrangement relationship of each component is not necessarily limited to orthogonal.

  Next, a configuration example of the recording head 1 will be described. FIG. 2 is an exploded perspective view of the recording head 1, and FIG. 3 is a cross-sectional view of the recording head 1 cut along the second direction Y.

  The flow path forming substrate 10 constituting the recording head 1 is made of, for example, a silicon single crystal substrate, and a diaphragm 50 is formed on one surface thereof. The diaphragm 50 is made of, for example, a silicon dioxide layer or a zirconium oxide layer, and may be a single layer or a laminated layer.

  A plurality of pressure generating chambers 12 are arranged along the first direction X on the flow path forming substrate 10. An ink supply path 14 is formed at one end of the pressure generation chamber 12 in the second direction Y. The pressure generation chamber 12 is connected to a communication portion 13 which is a part of a manifold 100 serving as a common ink chamber of the plurality of pressure generation chambers 12 through an ink supply path 14 and a communication path 15 provided for each pressure generation chamber 12. Communicate with. The ink supply path 14 is formed with a narrower width than the pressure generation chamber 12, and maintains a constant flow path resistance of ink flowing into the pressure generation chamber 12 from the communication portion 13.

  The nozzle plate 20 is fixed to the other surface of the flow path forming substrate 10 (the surface opposite to the vibration plate 50). The nozzle plate 20 is made of, for example, glass ceramics, a silicon single crystal substrate, or stainless steel.

  The nozzle plate 20 has a nozzle opening 21 communicating with the vicinity of the end of the pressure generating chamber 12 on the side opposite to the ink supply path 14. A plurality of nozzle openings 21 are arranged side by side on a straight line along the first direction X, thereby forming a nozzle row 22.

  The arrangement of the nozzle openings 21 is not limited, and it may be a staggered arrangement in which the second direction Y is shifted every other one along the first direction X. The nozzle opening 21 may be formed along the second direction Y, or may be formed along a direction that intersects both the first direction X and the second direction Y.

  On the vibration plate 50 formed on one surface of the flow path forming substrate 10, the first electrode 60, the piezoelectric layer 70, and the second electrode 80 are laminated by film formation and lithography to form the piezoelectric element 300. It is composed. In the present embodiment, the piezoelectric element 300 corresponds to a pressure generating unit that causes a pressure change in the ink in the pressure generating chamber 12.

  The piezoelectric element 300 refers to a portion including the first electrode 60, the piezoelectric layer 70, and the second electrode 80. In general, the piezoelectric element 300 is configured by using one electrode of the piezoelectric element 300 as a common electrode and patterning the other electrode and the piezoelectric layer 70 for each pressure generating chamber 12. In the present embodiment, the first electrode 60 is a common electrode and the second electrode 80 is an individual electrode. However, this may be reversed for the convenience of a drive circuit and wiring. In the present embodiment, the diaphragm 50 and the first electrode 60 act as a diaphragm. However, only the first electrode 60 may act as a diaphragm without providing the diaphragm 50. The piezoelectric element 300 itself may substantially double as a diaphragm.

  A lead electrode 90 is connected to the second electrode 80 of each piezoelectric element 300, and a drive signal is selectively supplied to each piezoelectric element 300 via the lead electrode 90.

  A protective substrate 30 is provided on the vibration plate 50. The protective substrate 30 is preferably made of substantially the same material as the thermal expansion coefficient of the flow path forming substrate 10, for example, glass or ceramic material. In the present embodiment, a silicon single crystal substrate made of the same material as the flow path forming substrate 10 is used.

  A manifold portion 31 is formed on the protective substrate 30. The manifold portion 31 is formed to penetrate the protective substrate 30 in the third direction Z and correspond to the plurality of pressure generating chambers 12 with the first direction X as the longitudinal direction. The manifold portion 31 communicates with the communication portion 13 of the flow path forming substrate 10 and constitutes a manifold 100 serving as a common ink chamber for the pressure generation chambers 12.

  A piezoelectric element holding portion 32 having a space that does not hinder the movement of the piezoelectric element 300 is provided in a region facing the piezoelectric element 300 of the protective substrate 30. The piezoelectric element holding part 32 only needs to have a space that does not hinder the movement of the piezoelectric element 300, and the space may be sealed or unsealed.

  The protective substrate 30 is provided with a through hole 33. The through hole 33 penetrates the protective substrate 30 in the third direction Z, and the vicinity of the end portion of the lead electrode 90 drawn from the piezoelectric element 300 is exposed in the through hole 33. The protective substrate 30 is joined to the diaphragm 50 via the adhesive 35, but the joining means of the protective substrate 30 and the diaphragm 50 is not limited to this. The protective substrate 30 may be bonded to the flow path forming substrate 10.

  A compliance substrate 40 is bonded to the protective substrate 30. The compliance substrate 40 includes a sealing film 41 and a fixing plate 42. The sealing film 41 is made of a material having low rigidity and flexibility, and the manifold 100 is sealed by the sealing film 41. The fixed plate 42 is formed of a relatively hard material, and an area of the fixed plate 42 facing the manifold 100 is an opening 43 from which the third direction Z is removed.

  The protective substrate 30 is provided with a drive circuit 120 that supplies a drive signal generated by the control device (the control device 200 shown in FIG. 1) to the piezoelectric element 300. As the driving circuit 120, for example, a circuit board or a semiconductor integrated circuit (IC) can be used. The drive circuit 120 is electrically connected to the lead electrode 90 via a connection wiring 121 made of a conductive wire such as a bonding wire.

  In the recording head 1 described above, the volume of the pressure generation chamber 12 is contracted by the displacement of the piezoelectric element 300 according to the drive signal to pressurize the ink, and the ink is ejected from the nozzle opening 21 communicating with the pressure generation chamber 12. Since pressure vibration may remain in the pressure generation chamber 12 after ink ejection (hereinafter, this residual pressure vibration may be referred to as “residual vibration”), the drive signal is used to suppress the residual vibration. A damping element is included.

  The damping element included in the drive signal will be described with reference to FIGS. 4 to 5 with reference to the configuration of the recording head 1. FIG. 4 is a diagram illustrating an example of a drive signal supplied to the recording head 1, and a vibration damping adjustment element that adjusts the timing for starting the vibration damping element is indicated by an arrow range. FIG. 5 is a view for explaining residual vibration in the pressure generation chamber 12.

  The drive signal supplied to the recording head 1 includes an element P01 that drops the voltage V to a first potential V1 that is lower than the intermediate potential Vm, an element P02 that maintains the first potential V1, and a second potential V2 that is higher than the intermediate potential Vm. Element P03 for increasing the voltage V to the end, element P04 for maintaining the second potential V2, element P05 for decreasing the voltage V to the intermediate potential Vm, and element P06 for maintaining the intermediate potential Vm. After the period of the element P05, the electrical connection with the piezoelectric element 300 is switched from the drive circuit 120 to the measurement circuit (not shown), so that the first electrode 60 and the second electrode 80 of the piezoelectric element 300 can be A voltage waveform as indicated by a solid line is detected. This is a counter electromotive voltage generated when pressure vibration remains in the pressure generating chamber 12 due to displacement of the piezoelectric element 300 by the drive signal, and the piezoelectric element 300 is displaced by the remaining pressure vibration.

  In the element P01, the piezoelectric element 300 is displaced in the direction in which the volume of the pressure generating chamber 12 is expanded from the initial state. As a result, the pressure in the pressure generation chamber 12 decreases, ink is supplied into the pressure generation chamber 12 from the manifold 100 side, and the meniscus in the nozzle opening 21 is drawn into the pressure generation chamber 12 side.

  The expansion state of the pressure generation chamber 12 is maintained during the element P02. In the pressure generation chamber 12, pressure vibration is generated due to the expansion of the volume of the pressure generation chamber 12 in the element P 01, and the element P 03 is reached at a predetermined timing according to the pressure vibration.

  In the element P03, the piezoelectric element 300 is displaced in a direction in which the volume of the pressure generating chamber 12 is contracted from the initial state. As a result, the ink in the pressure generating chamber 12 is pressurized, and the ink is ejected from the nozzle opening 21. In the present embodiment, the element P01, the element P02, and the element P03 are the first period in which the volume of the pressure generation chamber 12 is changed so as to form droplets that land on the recording sheet S.

  The element P04 corresponds to a vibration damping adjustment element that adjusts the timing for starting the vibration damping element (element P05) of the present embodiment. During the element P04, the contracted state of the pressure generating chamber 12 is maintained. In the pressure generation chamber 12, a pressure vibration is generated due to the contraction of the volume of the pressure generation chamber 12 in the element P03, and the element P05 is reached at a predetermined timing according to the pressure vibration.

  The element P05 is a damping element that changes the volume of the pressure generation chamber 12 and suppresses residual vibration in the pressure generation chamber 12 after the drive signal is supplied. In the element P05, the volume of the pressure generating chamber 12 that has been contracted so far expands and returns to the initial state. In the element P05, the pressure in the pressure generation chamber 12 decreases in accordance with the expansion of the volume of the pressure generation chamber 12. Therefore, depending on the phase of the pressure vibration in the pressure generation chamber 12 overlapping the element P05, And the pressure generated by the element P05 cancel each other out from the pressure change. Specifically, a period in which the pressure in the pressure generation chamber 12 increases due to pressure vibration in the pressure generation chamber 12, and a period of a damping element that expands the volume of the pressure generation chamber 12 to lower the pressure in the pressure generation chamber 12 At least partially overlap each other, canceling pressure changes with each other, and reducing the amplitude of residual vibration in the pressure generating chamber 12 after the drive signal is supplied.

  In this respect, the pressure vibration in the pressure generation chamber 12 caused by the element P03 continues while the volume of the pressure generation chamber 12 is maintained at the element P04. The element P04 adjusts its end timing, in other words, its length (the length Tpn of the damping adjustment element indicated by the arrow range in FIG. 4), thereby overlapping the element P05 that is the damping element. The phase of pressure oscillation in 12 can be adjusted.

  Thereafter, in the element P06, the volume of the pressure generation chamber 12 is maintained in the initial state. In general, even after the volume of the pressure generating chamber returns to the initial state, the pressure vibration (corresponding to the solid line in FIG. 5) remaining in the pressure generating chamber 12 may continue. Residual vibration occurs mainly due to ink ejection, and its amplitude An varies depending on the length Tpn of the vibration damping adjustment element. The residual vibration in the present embodiment refers to pressure vibration remaining in the pressure generation chamber 12 after the volume of the pressure generation chamber 12 returns to the initial state after ink ejection.

  The recording apparatus I can effectively suppress the amplitude of the residual vibration by optimizing the length Tpn of the vibration damping adjustment element. As a result, the piezoelectric element 300 is driven with a drive signal in which the length Tpn of the vibration damping adjustment element is optimized not only at the time of shipment but also due to deterioration of the configuration, change in ink characteristics, change of ink type, etc. It is possible to effectively suppress the residual vibration in the pressure generating chamber 12 over a long period of time. As a result, ink ejection defects can be effectively suppressed over a long period of time, and high drive stability can be ensured over a long period of time.

  A configuration example of such a control system of the recording apparatus I will be described. FIG. 6 is a functional block diagram showing parts related to the control of the recording apparatus I.

  The control apparatus 200 includes a control unit 210 that performs overall control of the recording apparatus I. The control unit 210 is configured around a microcomputer, and each unit is realized by executing a program stored in the storage unit 213 by the microcomputer.

  A print engine 220 and an external device 230 are electrically connected to the control unit 210. The control unit 210 receives print data from the external device 230 as a host computer, and transmits a busy signal or the like to the external device 230.

  The print engine 220 includes a recording head 1, a paper feed mechanism 221, a carriage mechanism 222, and the like. The paper feed mechanism 221 includes the transport roller 8 shown in FIG. 1, and the carriage mechanism 222 includes the carriage 3, the drive motor 6, and the timing belt 7 shown in FIG. In response to a signal from the control unit 210, the print engine 220 causes ink to be ejected from the recording head 1, and the paper feeding mechanism 221 sequentially feeds the recording sheets S in conjunction with the operation of the recording head 1, and the carriage mechanism 222 performs carriage. The recording head 1 is reciprocated along the axis 5.

  The control unit 210 includes an external interface 211 (external I / F 211), an internal interface 212 (internal I / F 212), a storage unit 213, a drive signal generation unit 214, and a control processing unit 215. ing.

  The control unit 210 receives various signals and data necessary for printing from the outside via the external I / F 211 and the internal I / F 212, and transmits them to the outside and inside. The storage unit 213 includes a RAM and a ROM (not shown). The RAM temporarily stores various data necessary for image printing, including print data received from the external device 230. The ROM stores a control program, font data, and the like.

  The drive signal generation unit 214 is configured to generate a drive signal for driving the recording head 1 and to transmit a signal to the recording head 1 via the internal I / F 212. The drive signal generation unit 214 is configured to receive an instruction signal for generating a predetermined calculation drive signal from the control processing unit 215 and generate a calculation drive signal based on the instruction signal. .

  The control processing unit 215 includes a CPU and the like. By executing the control program stored in the storage unit 213, print data is read from the RAM and font data stored in the ROM is stored. With reference to this, information necessary for printing is developed into dot pattern data. Then, the developed dot pattern data is transmitted to the print engine 220. Various signals necessary for driving the recording head 1, such as a clock signal, a latch signal, a change signal, pixel data, and setting data, are transmitted.

  A specific configuration example of the control processing unit 215 will be described with reference to FIGS. FIG. 7 is a functional block diagram showing a part related to the calculation of the appropriate length of the vibration damping adjustment element. FIG. 8 is a diagram illustrating an example of a calculation drive signal in which the lengths of the vibration damping adjustment elements are different from each other, and FIG. 9 is an example of a technique for detecting the amplitude of the residual vibration according to the length of the vibration damping adjustment element. FIG. The calculation drive signal is a signal used for obtaining an appropriate length of the vibration damping adjustment element, and elements other than the vibration damping adjustment element coincide with the elements of the drive signal used for normal printing.

  The control processing unit 215 includes a calculation time detection unit 241, a calculation drive signal generation instruction unit 242, an amplitude detection unit 243, and an appropriate length calculation unit 244.

  The calculation time detection unit 241 detects the time when the drive signal is updated by calculating the appropriate length of the vibration damping adjustment element. Here, the calculation timing detection unit 241 instructs the calculation drive signal generation instruction unit 242 every time a count value t of a timer counter (not shown) that operates when the power is turned on passes a predetermined set time t0. It is configured to transmit a signal. The set time t0 is a time less than the limit time in which the displacement of the damping element caused by the deterioration of the configuration, the change of the ink characteristics, the change of the ink type, and the like due to the use of the recording apparatus I is not allowed. . This type of limit time varies depending on the configuration and application of the recording apparatus I, the type of ink, the viscosity, and the like, but can be calculated in advance by testing or the like.

  The count value t of the timer corresponds to the operating time of the recording apparatus I. Since the calculation time detection unit 241 is configured to calculate an appropriate length every time the operating time of the recording apparatus I elapses the set time t0, the length of the vibration damping adjustment element during the operation of the recording apparatus I. The drive signal can be updated periodically so that the length becomes an appropriate length.

  Here, the count value t is stored even when the power is turned off, and it can be resumed from the count value t interrupted when the power is turned on next time. According to this, even in a usage situation in which the recording apparatus I is repeatedly operated in a short time, the drive signal can be updated in a timely manner so that the length of the vibration damping adjustment element becomes an appropriate length.

  However, the calculation time detection unit 241 may be configured to be able to detect the time for calculating the appropriate length of the vibration damping adjustment element and updating the drive signal. For example, the count value t may be reset when the power is turned off, and the operating time of the recording apparatus I may be estimated from other information without depending on the timer. Further, not the operating time of the recording apparatus I, but the number of printed sheets and the number of power inputs may be counted, and the timing for calculating the appropriate length of the vibration damping adjustment element may be detected according to the counted number. According to this, the appropriate length of the vibration damping adjustment element can be calculated periodically and the drive signal can be updated in accordance with the number of printed sheets and the number of power inputs. Further, the calculation time may be when it is detected that the type of ink used in the recording apparatus I has been changed, or when the user is instructed to optimize the length of the vibration damping adjustment element. You may combine calculation time.

  The calculation drive signal generation instruction unit 242 receives the instruction signal from the calculation timing detection unit 241 and generates a calculation drive signal for calculating the optimum length of the vibration damping adjustment element. In response to this, the instruction signal is transmitted. The calculation drive signal is a drive signal in which the lengths of the vibration damping adjustment elements are different from each other.

  The calculation drive signal according to the present embodiment uses a drive signal in which the length of the damping adjustment element of the current drive signal is the reference value, and the length of the damping adjustment element is the reference value as it is, and a predetermined value based on the reference value. A drive signal having a vibration damping adjustment element length Tp2 less by ΔT, and a drive signal having a vibration suppression adjustment element length Tp3 larger than the reference value by a predetermined value ΔT.

  The amplitude detector 243 detects the amplitude based on the inflection point that appears first in the residual vibration after the volume of the pressure generating chamber 12 returns to the initial state (after the damping element). When the calculation drive signal having the length Tp1 of the vibration damping adjustment element is supplied, the residual vibration that occurs after the volume of the pressure generating chamber 12 returns to the initial state is generated, and this is based on the inflection point that appears first. The amplitude An1 is detected. Since the amplitude based on the inflection point that appears first is the largest of the residual vibrations that are damped, the residual vibration is effectively and reliably suppressed by suppressing the amplitude An1 to a predetermined value or less. Can do.

  The amplitude of the residual vibration can be detected using, for example, a measurement circuit (not shown) for measuring a counter electromotive voltage signal generated in the piezoelectric element 300 due to the residual vibration. In the present embodiment, after supplying the calculation drive signal to the piezoelectric element 300, the back electromotive force signal can be measured by switching the electrical connection with the piezoelectric element 300 from the drive circuit 120 to the measurement circuit. As the amplitude of vibration increases, the displacement of the piezoelectric element 300 increases, and a back electromotive voltage signal corresponding to the displacement is input to the measurement circuit. A plurality of pressure values in the pressure generating chamber 12 are measured at a predetermined timing from the input back electromotive voltage signal, a transition of the residual vibration is predicted from the amplitude and timing, and the pressure is determined based on the transition of the residual vibration. It is comprised so that the amplitude of a vibration may be calculated | required.

  However, the method for detecting the amplitude of the residual vibration is not limited to the above. When sensor information for measuring the pressure in the pressure generating chamber 12 is input to the RAM or the like, the amplitude of the residual vibration may be directly detected by reading the sensor information.

  Based on the length of the vibration damping adjustment element and the amplitude of the residual vibration corresponding to the length of the vibration damping adjustment element, the appropriate length calculation unit 244 has a relationship between the amplitude of the residual vibration and the length of the vibration damping adjustment element. Is configured to anticipate. Here, the residual vibration amplitudes An1 to An3 with respect to the lengths Tp1 to Tp3 of the respective damping control elements of the calculation drive signal are plotted, and a predetermined quadratic function y is predicted.

  And it is comprised so that the amplitude Anmin used as the minimum value may be calculated as the appropriate length Tpmin of the damping control element by the predicted quadratic function y. By updating the drive signal with the damping control element as the appropriate length Tpmin, the residual vibration can be suppressed extremely effectively.

  When an amplitude An0 that is larger than the amplitude Anmin by a predetermined value ΔAn is allowable, the length range of the vibration suppression adjustment element that gives an amplitude lower than the amplitude An0 is obtained from the predicted quadratic function y, and the vibration suppression adjustment is performed from that range. The appropriate length of the element can be set. Also by this, the residual vibration in the pressure generating chamber 12 can be effectively suppressed over a long period of time, and ink ejection failure can be effectively suppressed over a long period of time.

  The relationship of the residual vibration amplitude to the length of the vibration damping adjustment element is not limited to the prediction by the quadratic function y. If the quadratic function y is not expected, for example, the residual vibration amplitudes of a plurality of calculation drive signals having different lengths of the vibration damping adjustment element are measured, and the calculation is an allowable amplitude An0 or less from among them. It is possible to set the length of one damping adjustment element in the drive signal for use to an appropriate length. In addition, in the calculation drive signal having an amplitude equal to or smaller than the amplitude An0, an intermediate value between the length of the longest damping adjustment element and the length of the shortest damping adjustment element can be set to an appropriate length. . Further, the residual vibration amplitudes of a plurality of calculation drive signals having different lengths of the vibration suppression adjustment element are measured, and the length of the vibration suppression adjustment element of the calculation drive signal from which the smallest amplitude is measured. Can be set to an appropriate length. The length of one vibration damping adjustment element of the calculation drive signal having an amplitude equal to or smaller than the amplitude An0, or the longest vibration suppression adjustment element in the calculation drive signal having an amplitude equal to or smaller than the amplitude An0. The intermediate value between the length of the vibration suppression adjustment element and the shortest vibration suppression adjustment element may not coincide with the appropriate length Tpmin of the vibration suppression adjustment element that gives the amplitude Anmin, but the amplitude of the calculation drive signal having an amplitude equal to or smaller than the amplitude An0. Regardless of the length of the damping adjustment element, the residual vibration in the pressure generating chamber 12 can be effectively suppressed over a long period of time.

  Thereafter, the appropriate length calculation unit 244 transmits an instruction signal to the drive signal generation unit 214 so as to update the drive signal with the calculated appropriate length of the vibration damping adjustment element.

  In the control according to the present embodiment, the method for obtaining the optimum length of the vibration damping adjustment element is not limited to the above. For example, in the present embodiment, three sets of residual vibration amplitudes corresponding to calculation drive signals having different lengths of the damping adjustment elements are detected, but four or more sets may be detected. As the number of detections increases, the time required for calculation and ink consumption increase, but the accuracy of the required appropriate length increases. Although control is possible even with two sets, it is desirable to detect at least three or more sets of residual vibration amplitudes according to the length of the vibration damping adjustment element in order to ensure accuracy. In terms of the balance of accuracy, speed, ink consumption, etc., it is preferable that the detection of the residual vibration amplitude according to the length of the vibration damping adjustment element is three.

  While the length of the vibration suppression adjustment element is updated in a timely manner, the length of the vibration suppression adjustment element used at that time is often not significantly different from the calculated appropriate length. Therefore, in the present embodiment, the calculation drive signal including the vibration suppression adjustment element shorter than the reference value, using the length Tp1 of the vibration suppression adjustment element of the drive signal currently in use as the reference value as the calculation drive signal, And a calculation drive signal including a vibration damping adjustment element longer than the value. According to this, the appropriate length of the vibration suppression adjustment element is likely to be included between the vibration suppression adjustment element shorter than the reference value and the vibration suppression adjustment element longer than the reference value. Therefore, in the relationship of the amplitude of the residual vibration with respect to the length of the vibration damping adjustment element of the quadratic function y predicted from the measurement result, between the vibration damping adjustment element shorter than the reference value and the vibration damping adjustment element longer than the reference value. Can easily include inflection points, and the relationship can be accurately predicted. As a result, the appropriate length of the vibration damping adjustment element can be accurately calculated.

  In the calculation drive signal, the tolerances of the different damping adjustment elements may be equal or different. The order in which the calculation drive signals having different lengths of the vibration damping adjustment elements are supplied is not limited. In the present embodiment, the control processing unit 215 and the drive signal generation unit 214 are configured separately, but each part or part of the control processing unit 215 is included in the drive signal generation unit 214. Also good.

  In the calculation drive signal, other elements other than the vibration damping adjustment element and the interval between the calculation drive signals (the interval between the element P01 to the element P06 and the next element P01 to the element P06) are stored in the storage unit 213 in advance. It can be obtained by referring to the stored data and information. In the present embodiment, the elements other than the vibration damping adjustment element and the calculation drive signal interval (the interval between the element P01 to the element P06 and the next element P01 to the element P06) are drive signals used during printing. Is consistent with

  A method for driving the recording apparatus I will be described with reference to FIG. FIG. 10 is a flowchart showing an example of a part related to calculation of the optimum length of the vibration damping adjustment element in the driving method of the recording apparatus.

  In step S1, it is determined whether or not the count value t of the timer counter that operates when the power is turned on exceeds a predetermined set time t0. Step S1 is repeated until it is determined that the count value t exceeds the set time t0. If it is determined that the count value t exceeds the set time t0, the process proceeds to step S2. In step S2, the count value t of the timer is reset, and the process proceeds to step S3.

  In step S3, a calculation drive signal is generated. In step S4, the generated calculation drive signal is supplied to the piezoelectric element 300 to calculate the residual vibration amplitude. In step S5, the obtained residual vibration amplitude is obtained. Based on the above, the appropriate length of the vibration damping adjustment element is calculated, and in the next step S6, the drive signal is updated so that the length of the vibration damping adjustment element becomes the calculated appropriate length, and the process returns to the start.

  According to the recording apparatus I described above, the length of the vibration damping adjustment element is optimized in a timely manner and the drive signal is updated. Therefore, not only at the time of shipment, the deterioration of the configuration due to use, the change in ink characteristics, the ink type Even for a change or the like, the piezoelectric element 300 can be driven by a drive signal in which the length of the vibration damping adjustment element is optimized, and the residual vibration in the pressure generation chamber 12 can be effectively suppressed over a long period of time. As a result, ink ejection defects can be effectively suppressed over a long period of time, and high drive stability can be ensured over a long period of time.

(Embodiment 2)
In the liquid ejecting apparatus and the driving method thereof according to the present embodiment, the lengths of the vibration suppression adjustment elements that supply calculation drive signals having different lengths of the vibration suppression adjustment elements and have a discharge failure detection level equal to or less than a predetermined value. The appropriate range is calculated, and the appropriate length of the vibration damping adjustment element applied to the drive signal used during actual printing is calculated in a timely manner to update the drive signal. Hereinafter, the same members as those in the first embodiment are denoted by the same reference numerals, and different portions will be mainly described.

  FIG. 11 is a functional block diagram showing portions related to the control of the recording apparatus I. The control apparatus 200A according to the present embodiment includes a control unit 210A that controls the entire recording apparatus. The controller 210A is electrically connected to the print engine 220A.

  The print engine 220A is provided with a discharge failure detection mechanism 223. The ejection failure detection mechanism 223 can be configured by an optical system sensor such as a scanner that reads a printing pattern in the recording apparatus I as an image and detects ejection failure (dot missing).

  FIG. 12 is a functional block diagram showing parts related to the control of the recording apparatus I according to the present embodiment. FIG. 13 is a diagram illustrating an example of a method for detecting a discharge failure that occurs according to the length of the vibration damping adjustment element.

  The control processing unit 215A includes a calculation time detection unit 241, a calculation drive signal generation instruction unit 242A, a discharge failure detection unit 245, and an appropriate length calculation unit 244A. Among these, the calculation time detection unit 241 is configured in the same manner as in the first embodiment.

  The calculation drive signal generation instruction unit 242A receives the instruction signal from the calculation timing detection unit 241, and instructs the drive signal generation unit 214 to generate a calculation drive signal for calculating the optimum length of the vibration damping adjustment element. In response to this, the instruction signal is transmitted. Further, the ejection failure detection unit 245 is configured to detect the degree of ejection failure according to the calculation drive signals having different lengths of the vibration damping adjustment elements based on information from the ejection failure detection mechanism 223. Yes.

  The drive signal for calculation of the present embodiment uses the drive signal whose length is the reference value as the length of the damping adjustment element of the current driving signal, and the length of the damping adjustment element as the reference value. A drive signal whose length is shorter than the reference value and a drive signal whose length of the vibration damping adjustment element is longer than the reference value are included.

  In the present embodiment, a calculation drive signal having a vibration damping adjustment element length Ta1 shorter than the reference value by ΔT, a calculation drive signal having a vibration suppression adjustment element length Ta2 shorter than the length Ta1 by ΔT,... In order, supply of calculation drive signals having different lengths of the vibration damping adjustment elements is instructed so that the vibration damping adjustment elements are shortened. The print pattern printed by each calculation drive signal is read by the discharge failure detection mechanism 223, and the discharge failure detection unit 245 determines the presence or absence of discharge failure from the read image of the print pattern. Eventually, the ejection failure detection unit 245 detects the occurrence of ejection failure from the image of the print pattern by the calculation drive signal having the length Tax of the vibration damping adjustment element. At this time, the length Tax-1 of the vibration suppression adjustment element of the calculation drive signal immediately before the drive signal for calculation having the length Tax of the vibration suppression adjustment element is stored as the lower limit value TaL.

  Similarly, a calculation drive signal having a vibration damping adjustment element length Tb1 longer than the reference value by ΔT, a calculation drive signal having a vibration suppression adjustment element length Tb2 longer than the length Tb1 by ΔT, and so on. Then, it is instructed to supply calculation drive signals having different lengths of the vibration damping adjustment element so that the vibration damping adjustment element becomes longer. The print pattern printed by each calculation drive signal is read by the discharge failure detection mechanism 223, and the discharge failure detection unit 245 determines the presence or absence of discharge failure from the read image of the print pattern. Eventually, the ejection failure detection unit 245 detects the occurrence of ejection failure from the image of the print pattern by the calculation drive signal having the length Tbx of the vibration damping adjustment element. At this time, the length Tbx−1 of the damping adjustment element of the calculation driving signal immediately before the calculation driving signal having the length Tbx of the damping adjustment element is stored as the upper limit value TbH.

  The appropriate length calculation unit 244A calculates the appropriate length from the length of the vibration damping adjustment element within the range of the lower limit value TaL and the upper limit value TbH. Here, an intermediate value between the lower limit value TaL and the upper limit value TbH is calculated as the appropriate length of the vibration damping adjustment element. Thereby, ink ejection defects can be effectively suppressed. Note that the target of ejection failure detection is a predetermined nozzle range, that is, one nozzle row or all nozzles may be used.

  Also in the calculation drive signal of the present embodiment, the tolerances of the different damping adjustment elements may be equal or different. The order in which the calculation drive signals having different lengths of the vibration damping adjustment elements are supplied is not limited. Each part or part of the control processing unit 215A may be included in the drive signal generation unit 214.

  If a discharge failure is detected even in one of the detection target nozzles, the discharge failure detection unit 245 detects the calculation drive signal immediately before the calculation drive signal in which the discharge failure is detected, in other words, the discharge failure is detected. The length of the vibration damping adjustment element corresponding to the length close to the reference value is set to an upper limit value or a lower limit value by one step from the length of the detected vibration damping adjustment element of the drive signal for calculation. That is, the range of the lower limit value TaL and the upper limit value TbH is a range in which the number of ejection defects detected is zero. On the other hand, when some discharge failure is allowed, the discharge failure detection unit 245 determines the range of the length of the vibration damping adjustment element in which the discharge failure detection degree is equal to or less than the predetermined value N0 (the lower limit value Ta0 shown in FIG. 13). And a range consisting of the upper limit value Tb0). The predetermined value N0 is a limit value at which ejection failure cannot be permitted.

  As a means for detecting the degree of ejection failure, a voltage is applied between the inspection region made of a predetermined liquid absorber and the nozzle plate 20 regardless of the ejection failure detection unit 245 and the ejection failure detection mechanism 223. By discharging the charged ink and discharging the charged ink as ink droplets, a potential signal representing a change in potential between the inspection region and the nozzle plate 20 is output, thereby causing ejection failure based on the amplitude of the potential signal. A detection method may be used. Further, after driving the piezoelectric element 300, a counter electromotive voltage generated in the piezoelectric element 300 may be detected to detect ejection failure from the residual vibration state, for example, the period and amplitude of the residual vibration.

  A method for driving the recording apparatus will be described with reference to FIG. FIG. 14 is a flowchart showing an example of a portion related to calculation of the optimum length of the vibration damping adjustment element in the driving method of the recording apparatus according to the present embodiment.

  In step S1, it is determined whether or not the count value t of the timer counter that operates when the power is turned on exceeds a predetermined set time t0. Step S1 is repeated until it is determined that the count value t exceeds the set time t0. If it is determined that the count value t exceeds the set time t0, the process proceeds to step S2. In step S2, the count value t of the timer is reset, and the process proceeds to step S3.

  In steps S3 to S6, a calculation drive signal is generated and supplied, a discharge failure corresponding to the calculation drive signal is detected, and a lower limit value of the optimum length range of the vibration damping adjustment element is obtained. First, in step S3, when the current damping control element length Tp1 is used as a reference value, the generation of a calculation drive signal having a damping control element length Ta1 shorter than the reference value by a predetermined value ΔT is instructed. . Next, in step S4, the generated drive signal for calculation is supplied to the piezoelectric element 300, and the degree of ejection failure is detected from the printed pattern. In step S5, the length of the damping adjustment element Ta1 is calculated. It is determined whether the degree of ejection failure in the drive signal exceeds a predetermined value, and if it is determined that it does not exceed the predetermined value, the process returns to step S3. In the returned step S3, generation of a calculation drive signal having a vibration damping adjustment element length Ta2 shorter than the current vibration damping adjustment element length Ta1 by a predetermined value ΔT is instructed, and in step S4 again the degree of ejection failure. Is detected. Then, while repeating steps S3 to S5, each time the process returns to step S3, the length of the vibration damping adjustment element is shortened by a predetermined value ΔT. If it is determined in step S5 that the ejection failure degree exceeds a predetermined value in the print pattern printed by the drive signal for calculating the vibration suppression adjustment element length in Tax, in step S6, the previous vibration suppression adjustment is performed. The element length Tax-1 is stored as the lower limit value TaL, and the process proceeds to step S7. That is, the lower limit value TaL is the length of the shortest vibration damping adjustment element at which the degree of ejection failure is not more than a predetermined value.

  In steps S7 to S10, a calculation drive signal in which the length of the vibration suppression adjustment element is gradually increased is generated and supplied, and an ejection failure corresponding to the calculation drive signal is detected, and the optimum length of the vibration suppression adjustment element is detected. Find the upper limit of the range. First, in step S7, generation of a calculation drive signal having a length Tb1 of the vibration damping adjustment element that is longer than the reference value by a predetermined value ΔT when the current length Tp1 of the vibration damping adjustment element is used as a reference value is instructed. . Next, the calculation drive signal generated in step S8 is supplied to the piezoelectric element 300, and the degree of ejection failure is detected from the printed pattern. In step S9, the calculation drive having the length Tb1 of the vibration damping adjustment element is detected. It is determined whether the degree of ejection failure in the signal exceeds a predetermined value, and if it is determined that it does not exceed the predetermined value, the process returns to step S7. In the returned step S7, the generation of a calculation drive signal having a vibration damping adjustment element length Tb2 longer than the current vibration damping adjustment element length Tb1 by a predetermined value ΔT is instructed, and in step S8 again the degree of ejection failure. Is detected. Then, while repeating steps S7 to S9, each time the process returns to step S7, the length of the vibration damping adjustment element is increased by a predetermined value ΔT. If it is determined in step S9 that the ejection failure degree exceeds the predetermined value in the print pattern printed by the drive signal for calculating Tbx, the length of the vibration damping adjustment element is the length of the previous vibration damping adjustment element. Tbx-1 is stored as the upper limit value TbH, and the process proceeds to step S10. That is, the upper limit value TbH is the length of the longest vibration damping adjustment element at which the degree of ejection failure is not more than a predetermined value. Note that the order of steps S3 to S6 and steps S7 to S10 may be reversed.

  Here, the range of the lower limit value TaL and the upper limit value TbH in which the degree of ejection failure is zero is detected, and the ejection failure of ink can be suppressed extremely effectively over a long period of time. Therefore, high driving stability can be ensured extremely reliably over a long period of time.

  In step S11, a value within the range between the lower limit value TaL and the upper limit value TbH is calculated as the optimum length of the vibration damping adjustment element, and in the next step S12, the calculated optimum vibration damping adjustment element length is obtained. Update the drive signal to return to the start.

  According to the recording apparatus I described above, the length of the vibration damping adjustment element is optimized in a timely manner and the drive signal is updated. Therefore, not only at the time of shipment, the deterioration of the configuration due to use, the change in ink characteristics, the ink type Even for a change or the like, the piezoelectric element 300 can be driven by a drive signal in which the length of the vibration damping adjustment element is optimized, and the ink ejection failure caused by the residual vibration in the pressure generation chamber 12 is effective over a long period of time. Can be suppressed. Therefore, high driving stability can be ensured over a long period of time.

  In the present embodiment, in addition to updating the length of the vibration damping adjustment element of the drive signal with the optimum length, the interval of the drive signal can be updated to an appropriate one. The interval between the drive signals is the interval between the element P01 to the element P06 and the next element P01 to the element P06. In this case, the calculation drive signal is supplied while changing the interval of the calculation drive signal to detect the ejection failure. According to this, in addition to optimizing the length of the vibration damping adjustment element, it is possible to obtain an appropriate drive signal including the interval of the drive signal, so that the ink caused by residual vibration in the pressure generation chamber 12 can also be obtained. Discharge failure can be suppressed extremely effectively over a long period of time, and high drive stability can be ensured over a long period of time.

(Other embodiments)
As mentioned above, although one Embodiment of this invention was described, the basic composition of this invention is not limited to what was mentioned above.

  For example, in the drive signal of the present embodiment, the vibration damping adjustment element that optimizes the length corresponds to the element P04 shown in FIGS. As described above, the element P04 changes the volume of the pressure generation chamber 12 to change the volume of the pressure generation chamber 12 after the first period in which the volume of the pressure generation chamber 12 is changed so as to form a droplet to land on the recording sheet S. This is a vibration damping adjustment element that adjusts the timing for starting the vibration damping element P05 for suppressing the residual vibration in the chamber 12. Due to the length of the element P04, the pressure generation chamber is increased by the period in which the pressure in the pressure generation chamber 12 increases due to the pressure vibration in the pressure generation chamber 12 after the contraction element P03, and the expansion of the volume of the pressure generation chamber 12 by the damping element. The pressure reduction chamber 12 is adjusted so that the residual vibration after the pressure generation chamber 12 returns to the initial state is weakened by mutually canceling the pressure changes by overlapping at least a part of the period in which the pressure in the chamber 12 is lowered.

  FIG. 15 is an example of a drive signal different from the drive signal described in the present embodiment. The drive signal includes an element P11 that lowers the voltage V to the first potential V1 that is lower than the intermediate potential Vm, an element P12 that maintains the first potential V1, and a third potential V3 that is higher than the first potential V1 and lower than the intermediate potential Vm. An element P13 that increases the voltage V to a level, an element P14 that maintains the third potential V3, an element P15 that increases the voltage V to a second potential V2 that is higher than the intermediate potential Vm, and an element P16 that maintains the second potential V2. The element P17 reduces the voltage V to the intermediate potential Vm, and the element P18 maintains the intermediate potential Vm.

  In such a drive signal, the element P11, the element P12, and the element P13 correspond to a first period in which the volume of the pressure generation chamber 12 is changed so as to form droplets that land on the recording sheet S. It corresponds to the adjustment element, and the element P15 corresponds to the damping element. The element P14 is after the first period in which the volume of the pressure generation chamber 12 is changed. The element P14 maintains the volume of the pressure generating chamber 12, and the period during which the pressure in the pressure generating chamber 12 decreases due to the pressure vibration in the pressure generating chamber 12, and the volume of the pressure generating chamber 12 by the damping element P15. The start timing of the damping element P15 is adjusted so that the period in which the pressure in the pressure generation chamber 12 rises due to the contraction overlaps at least partly and the residual vibration in the pressure generation chamber 12 is suppressed.

  FIG. 16 is an example of a drive signal further different from the drive signal described above. Such a drive signal raises the voltage V to an element P21 that lowers the voltage V to a first potential V1 that is lower than the intermediate potential Vm, an element P22 that maintains the first potential V1, and a second potential V2 that is higher than the intermediate potential Vm. An element P23, an element P24 that maintains the second potential V2, an element P25 that reduces the voltage V to a third potential V3 that is lower than the intermediate potential Vm and higher than the first potential V1, and an element P26 that maintains the third potential V3 The element P27 increases the voltage V to the intermediate potential Vm, and the element P28 maintains the intermediate potential Vm.

  In such a drive signal, the element P21, the element P22, the element P23, the element P24, and the element P25 correspond to a first period in which the volume of the pressure generation chamber 12 is changed in order to form droplets that land on the recording sheet S. Element P26 corresponds to a vibration damping adjustment element, and element P27 corresponds to a vibration damping element. The element P26 is after the first period in which the volume of the pressure generation chamber 12 is changed. The element P26 maintains the volume of the pressure generation chamber 12, the period during which the pressure in the pressure generation chamber 12 decreases due to the pressure vibration in the pressure generation chamber 12, and the volume of the pressure generation chamber 12 by the damping element P15. The start timing of the damping element P27 is adjusted so that the period in which the pressure in the pressure generation chamber 12 rises due to the contraction overlaps at least partly and residual vibration in the pressure generation chamber 12 is suppressed.

  In the drive signals described above, depending on the configuration, application, and type of the device, there is a signal whose transition of voltage is opposite to that shown in FIGS. 4 and 8 and FIGS. 15 to 16. Regardless of the waveform, the drive signal changes the volume of the pressure generating chamber 12 to form a droplet to land on the recording sheet S, and the volume of the pressure generating chamber 12 after the first period. The present embodiment includes a vibration damping adjustment element that maintains the pressure and a vibration suppression element that changes the volume of the pressure generation chamber 12 after the vibration suppression adjustment element and suppresses residual vibration in the pressure generation chamber. It becomes applicable with.

  Embodiment 1 and Embodiment 2 can be combined. Depending on the interval of the drive signals, etc., any mode may be implemented.

  The control program for appropriately calculating the appropriate length of the vibration damping adjustment element described in the above embodiment is a floppy disk connected directly via the external I / F 214 or connected via the external device 230. It can also be read from a recording medium such as a CDROM, DVDROM, or USB memory. The control program may be provided in the external device 230 as a printer driver. When the control program is provided in the external device 230, the control unit 210 according to the present embodiment is the external device 230 including the control program.

  In the embodiment described above, the thin film piezoelectric element 300 has been described as the pressure generating means for causing a pressure change in the pressure generating chamber 12, but the present invention is not particularly limited thereto. A thick film type piezoelectric actuator formed by a method, a longitudinal vibration type piezoelectric actuator in which piezoelectric materials and electrode forming materials are alternately stacked and expanded and contracted in the axial direction can be used. Also, as a pressure generating means, a heating element is arranged in the pressure generating chamber, and droplets are discharged from the nozzle opening by bubbles generated by the heat generated by the heating element, or static electricity is generated between the diaphragm and the electrode. Thus, a so-called electrostatic actuator that discharges liquid droplets from the nozzle openings by deforming the diaphragm by electrostatic force can be used.

  In the ink jet recording apparatus I described above, the recording head 1 is mounted on the carriage 3 and moved in the second direction Y, which is the main scanning direction. However, the present invention is not particularly limited thereto. The present invention can also be applied to a so-called line-type recording apparatus in which the head 1 is fixed and printing is performed simply by moving the recording sheet S such as paper in the first direction X. In the case of a line type recording apparatus, the direction in which the nozzle openings 21 are arranged side by side is the second direction Y orthogonal to the conveyance direction (first direction X) of the recording sheet S, and main scanning that defines the main scanning data number The direction can be replaced with a first direction X that is a relative movement direction of the recording head 1 and the recording sheet S.

  Furthermore, the present invention is intended for a wide range of liquid jet heads in general, for example, for manufacturing recording heads such as various ink jet recording heads used in image recording apparatuses such as printers, and color filters such as liquid crystal displays. The present invention can also be applied to a coloring material ejecting head, an organic EL display, an electrode material ejecting head used for forming electrodes such as an FED (field emission display), a bioorganic matter ejecting head used for biochip manufacturing, and the like.

  DESCRIPTION OF SYMBOLS I ... Inkjet recording apparatus (liquid ejecting apparatus), 1 ... Inkjet recording head (liquid ejecting head), 2 ... Ink cartridge, 3 ... Carriage, 4 ... Apparatus body, 5 ... Carriage shaft, 6 ... Drive motor, 7 ... Timing belt, 8 ... conveying roller, 10 ... channel forming substrate, 12 ... pressure generating chamber, 13 ... communication portion, 14 ... ink supply passage, 15 ... communication passage, 20 ... nozzle plate, 21 ... nozzle opening, 22 ... nozzle , 30 ... protective substrate, 31 ... manifold portion, 32 ... piezoelectric element holding portion, 33 ... through hole, 35 ... adhesive, 40 ... compliance substrate, 41 ... sealing film, 42 ... fixing plate, 43 ... opening, DESCRIPTION OF SYMBOLS 50 ... Diaphragm, 60 ... 1st electrode, 70 ... Piezoelectric layer, 80 ... 2nd electrode, 90 ... Lead electrode, 100 ... Manifold, 120 ... Drive circuit, 121 ... Connection wiring, 2 DESCRIPTION OF SYMBOLS 0 ... Control apparatus, 210 ... Control part, 211 ... External interface, 212 ... Internal interface, 213 ... Memory | storage part, 214 ... Drive signal generation part, 215 ... Control processing part, 220 ... Print engine, 221 ... Paper feed mechanism, 222 ... Carriage mechanism, 230 ... External device, 241 ... Calculation time detection unit, 242 ... Calculation drive signal generation instruction unit, 243 ... Amplitude detection unit, 244 ... Appropriate length calculation unit, 300 ... Piezoelectric element, I ... Inkjet recording Device, P01 to P06 ... element, P11 to P18 ... element, P21 to P28 ... element, S ... recording sheet, X ... first direction, Y ... second direction, Z ... third direction

Claims (7)

A liquid ejecting head having a nozzle opening from which liquid is discharged, a pressure generating chamber communicating with the nozzle opening, and a pressure generating means that changes a volume of the pressure generating chamber by being displaced according to a drive signal;
A controller that generates the drive signal and supplies the drive signal to the liquid jet head,
The drive signal includes a first period in which the volume of the pressure generation chamber is changed, a vibration suppression adjustment element that maintains the volume of the pressure generation chamber after the first period, and the vibration control element after the vibration suppression adjustment element. A damping element that changes the volume of the pressure generating chamber to suppress residual vibration in the pressure generating chamber,
The control unit supplies drive signals having different lengths of the damping control elements to the liquid jet head, detects the amplitude of residual vibration in the pressure generation chamber after supplying the drive signal, and detects the amplitude. Calculating an appropriate length of the vibration damping adjustment element based on the length of the vibration damping adjustment element of the drive signal that is less than or equal to a predetermined value, and driving the drive signal including the vibration suppression adjustment element of the appropriate length A liquid ejecting apparatus characterized by updating a signal.   2. The liquid ejecting apparatus according to claim 1, wherein the control unit calculates the appropriate length every time an operation time of the liquid ejecting apparatus elapses a predetermined time.   The control unit calculates the appropriate length by detecting at least three sets of the amplitude according to the length of the vibration suppression adjustment element by varying the length of the vibration suppression adjustment element. The liquid ejecting apparatus according to claim 1 or 2.   The control unit predicts the relationship of the amplitude to the length of the vibration suppression adjustment element based on the length of the vibration suppression adjustment element and the amplitude according to the length of the vibration suppression adjustment element, The liquid ejection according to claim 1, wherein a length of the vibration damping adjustment element that minimizes the amplitude based on the predicted relationship is calculated as the appropriate length. apparatus. A liquid ejecting head comprising: a nozzle opening from which liquid is discharged; a pressure generating chamber communicating with the nozzle opening; and a pressure generating means that changes a volume of the pressure generating chamber by being displaced according to a driving signal; A control unit that generates a signal and supplies the signal to the liquid ejecting head, and a driving method of the liquid ejecting apparatus,
The drive signal includes a first period in which the volume of the pressure generation chamber is changed, a vibration suppression adjustment element that maintains the volume of the pressure generation chamber after the first period, and the vibration control element after the vibration suppression adjustment element. A damping element that changes the volume of the pressure generating chamber to suppress residual vibration in the pressure generating chamber,
Supplying drive signals with different lengths of the vibration damping adjustment elements to the pressure generating means;
Detecting the amplitude of residual vibration in the pressure generating chamber each time a drive signal having a different length of the vibration damping adjustment element is supplied;
Calculate the appropriate length of the vibration damping adjustment element that the amplitude is less than a predetermined value,
The driving method of the liquid ejecting apparatus, wherein the driving signal is updated so that the length of the vibration damping adjustment element becomes the appropriate length. A liquid ejecting head comprising: a nozzle opening through which liquid is discharged; a pressure generating chamber communicating with the nozzle opening; and a pressure generating means that changes a volume of the liquid in the pressure generating chamber by being displaced according to a drive signal. ,
A controller that generates the drive signal and supplies the drive signal to the liquid jet head,
The drive signal includes a first period in which the volume of the pressure generation chamber is changed, a vibration suppression adjustment element that maintains the volume of the pressure generation chamber after the first period, and the vibration control element after the vibration suppression adjustment element. A damping element that expands the volume of the pressure generation chamber and suppresses residual vibration in the pressure generation chamber,
The control unit supplies drive signals having different lengths of the vibration damping adjustment elements to the liquid ejecting head, and a degree of detection of defective ejection of liquid from the liquid ejecting head due to the supply of the drive signal is equal to or less than a predetermined value. A drive signal including a vibration suppression adjustment element of the appropriate length, calculating a proper length of the vibration suppression adjustment element based on a value within the range The liquid ejecting apparatus is characterized in that the drive signal is updated. A liquid ejecting head comprising: a nozzle opening from which liquid is discharged; a pressure generating chamber communicating with the nozzle opening; and a pressure generating means that changes a volume of the pressure generating chamber by being displaced according to a driving signal; A control unit that generates a signal and supplies the signal to the liquid ejecting head, and a driving method of the liquid ejecting apparatus,
The drive signal includes a first period in which the volume of the pressure generation chamber is changed, a vibration suppression adjustment element that maintains the volume of the pressure generation chamber after the first period, and the vibration control element after the vibration suppression adjustment element. A damping element for changing the volume of the pressure generating chamber to suppress residual vibration in the pressure generating chamber,
Supplying drive signals with different lengths of the vibration damping adjustment elements to the pressure generating means;
Detecting a liquid ejection failure from the liquid ejecting head due to the supply of the drive signal;
The drive signal is updated to a drive signal including the damping element having an appropriate length calculated based on a value within a range of the length of the damping adjustment element where the detection degree of the ejection failure is equal to or less than a predetermined value. A method for driving a liquid ejecting apparatus.

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