JP2015116796A - Liquid jet device, and method for controlling liquid jet device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid jet device and a method for controlling the liquid jet device capable of making constant the flight speed of the liquid regardless of number of times of continuous jet.SOLUTION: The liquid jet device configured so as to select from a first jet drive pulse, a second jet drive pulse set so as to make a flight speed of ink jetted from a nozzle larger than that in the case of the first jet drive pulse, and a third jet drive pulse set so as to make a flight speed of ink jetted from the nozzle smaller than that in the case of the first jet drive pulse. When ink is continuously jetted from the nozzle, first jet is performed by using the first jet drive pulse, second jet to n-th jet are performed by using the second jet drive pulse, and (n+1)-th and subsequent jet are performed by using the third jet drive pulse.

Description

  The present invention relates to a liquid ejecting apparatus such as an ink jet recording apparatus, and a control method for the liquid ejecting apparatus, and in particular, drives the pressure generating means by applying a driving waveform included in a driving signal to the pressure generating means, The present invention relates to a liquid ejecting apparatus that ejects a liquid from a nozzle by causing a pressure fluctuation in a liquid in a pressure chamber communicating with the nozzle, and a control method for the liquid ejecting apparatus.

  The liquid ejecting apparatus includes a liquid ejecting head and ejects (discharges) various liquids from the liquid ejecting head. As this liquid ejecting apparatus, for example, there are image recording apparatuses such as an ink jet printer and an ink jet plotter. Recently, various types of liquid ejecting apparatuses are utilized by utilizing the feature that a very small amount of liquid can be accurately landed on a predetermined position. It is also applied to devices. For example, a display manufacturing apparatus for manufacturing a color filter such as a liquid crystal display, an electrode forming apparatus for forming an electrode such as an organic EL (Electro Luminescence) display or FED (surface emitting display), a chip for manufacturing a biochip (biochemical element) Applied to manufacturing equipment. The recording head for the image recording apparatus ejects liquid ink, and the color material ejecting head for the display manufacturing apparatus ejects solutions of R (Red), G (Green), and B (Blue) color materials. The electrode material ejecting head for the electrode forming apparatus ejects a liquid electrode material, and the bioorganic matter ejecting head for the chip manufacturing apparatus ejects a bioorganic solution.

  The liquid ejecting head mounted on the liquid ejecting apparatus is, for example, a piezoelectric element, a heating element, or a pressure generating unit that causes pressure fluctuation in the liquid in the pressure chamber communicating with the nozzle that ejects the liquid and ejects the liquid from the nozzle. It has an electrostatic actuator. In the liquid ejecting apparatus, the driving waveform (driving pulse) generated by the driving signal generating unit is applied to the pressure generating unit, thereby driving the pressure generating unit to eject the liquid.

  By the way, when the liquid is continuously ejected from the nozzles of the liquid ejecting head, a phenomenon occurs in which the flying speed of the liquid ejected later changes with respect to the flying speed of the liquid ejected first. Specifically, there is a tendency for the liquid flight speed to increase as the number of ejections increases. As a result, there arises a problem that the landing position of the liquid with respect to the liquid landing target such as a recording medium is deviated from the original target position. For this reason, by gradually decreasing the voltage of the drive pulse for driving the pressure generating means of the liquid ejecting head according to the number of ejections, the flying speed and the ejection amount (hereinafter referred to as ejection characteristics as appropriate) are constant. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 2003-080741

  However, although the change in the flight speed during continuous injection tends to increase as a whole according to the number of injections, it may partially decrease in reverse from the first flight speed. That is, actually, the flying speed of the liquid does not change linearly according to the number of ejections. For this reason, the above-described configuration has a problem that the flying speed cannot be made completely constant.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a liquid ejecting apparatus capable of keeping the flying speed of liquid constant regardless of the number of continuous ejections, and control of the liquid ejecting apparatus. It is to provide a method.

The liquid ejecting apparatus of the present invention has been proposed to achieve the above object, and has a nozzle for ejecting liquid and pressure generating means for causing pressure fluctuation in the liquid in the liquid flow path communicating with the nozzle. And a liquid ejecting head that ejects liquid from the nozzles by applying a driving waveform to the pressure generating means and driving it,
Compared to the case of the first drive waveform, the second drive waveform set so that the flying speed of the liquid ejected from the nozzle is higher than that of the first drive waveform, and the case of the first drive waveform. And a third drive waveform set so that the flying speed of the liquid ejected from the nozzle is reduced, and is selectable.
In the case where liquid is continuously ejected from the nozzle, the first first ejection is performed using the first driving waveform, and the second to nth ejections are performed using the second driving waveform. Injection is performed, and the (n + 1) th and subsequent injections are performed using the third drive waveform.

  According to the present invention, when liquid is continuously ejected from the nozzle, the first first ejection is performed using the first driving waveform, and the second and subsequent ejections are performed using the second driving waveform. By performing the ejection up to the eyes and performing the (n + 1) th and subsequent ejections using the third drive waveform, the flying speed of the ejected liquid is determined regardless of the number of ejections when the liquid is ejected continuously. It becomes possible to approach the flying speed of the first first shot. As a result, it is possible to suppress problems such as displacement of the landing position of the liquid on the liquid landing target such as a recording medium.

  In the above configuration, when the voltage of the first drive waveform is V1, the voltage of the second drive waveform is V2, and the voltage of the third drive waveform is V3, V3 <V1 <V2. It is possible to adopt.

  According to this configuration, in the case where the amount of the liquid changes with the change in the flying speed of the liquid, the flying speed and the amount of the ejected liquid are set to the first flying speed regardless of the number of ejections. And it becomes possible to approach the liquid amount.

In the above configuration, the first drive waveform, the second drive waveform, and the third drive waveform may generate the pressure so as to increase the pressure in the liquid flow path in order to eject liquid from the nozzle. Each having a waveform element driving means,
The change rate of the potential change of the waveform element in the first drive waveform is G1, the change rate of the potential change of the waveform element in the second drive waveform is G2, and the potential change of the waveform element in the third drive waveform. It is also possible to adopt a configuration in which | G3 | <| G1 | <| G2 | when the change rate is G3.

  According to this configuration, in the case where the amount of liquid hardly changes even when the liquid flying speed changes, the liquid flying speed is maintained at a constant level regardless of the number of ejections. It becomes possible to approach the flying speed of the eyes.

The control method of the liquid ejecting apparatus of the present invention includes a nozzle that ejects the liquid, and a pressure generating unit that causes a pressure fluctuation in the liquid in the liquid flow path that communicates with the nozzle. A method of controlling a liquid ejecting apparatus including a liquid ejecting head that ejects liquid from a nozzle by applying and driving
Compared to the case of the first drive waveform, the second drive waveform set so that the flying speed of the liquid ejected from the nozzle is higher than that of the first drive waveform, and the case of the first drive waveform. The liquid can be ejected using the third driving waveform set so that the flying speed of the liquid ejected from the nozzle is reduced,
In the case where liquid is continuously ejected from the nozzle, the first first ejection is performed using the first driving waveform, and the second to nth ejections are performed using the second driving waveform. Injection is performed, and the (n + 1) th and subsequent injections are performed using the third drive waveform.

2 is a block diagram illustrating an electrical configuration of a printer. FIG. 2 is a perspective view illustrating an internal configuration of the printer. FIG. FIG. 3 is a cross-sectional view of a main part illustrating the configuration of a recording head. It is a wave form diagram explaining the structure of a drive signal. It is a wave form diagram explaining the difference in the structure of an ejection drive pulse. It is a graph explaining the relationship between the frequency | count of ejection at the time of continuous ejection, and the flying speed of an ink. It is a wave form diagram explaining the structure of the injection drive pulse in 2nd Embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. In the embodiments described below, various limitations are made as preferred specific examples of the present invention. However, the scope of the present invention is not limited to the following description unless otherwise specified. However, the present invention is not limited to these embodiments. In the following, an ink jet recording apparatus (hereinafter referred to as a printer) will be described as an example of the liquid ejecting apparatus of the invention.

  FIG. 1 is a block diagram illustrating the electrical configuration of the printer 1, and FIG. 2 is a perspective view illustrating the internal configuration of the printer 1. The external device 2 is an electronic device such as a computer, a digital camera, a mobile phone, or a portable information terminal. The external device 2 is electrically connected to the printer 1 wirelessly or in a wired manner. In order to print an image or text on the recording medium S such as recording paper in the printer 1, print data corresponding to the image or the like is transmitted to the printer. 1 to send.

  The printer 1 in this embodiment includes a paper feed mechanism 3, a carriage moving mechanism 4, a linear encoder 5, a print engine 13 such as a recording head 6, and a printer controller 7. The recording head 6 is attached to the bottom side of a carriage 16 on which an ink cartridge 17 (liquid supply source) is mounted. The carriage 16 is configured to reciprocate along the guide rod 18 by the carriage moving mechanism 4. That is, the printer 1 sequentially transports the recording medium S such as recording paper (a kind of landing target) by the paper feeding mechanism 3 and the recording head 6 with respect to the recording medium in the width direction (main scanning direction). The ink, which is a kind of liquid, is ejected from the nozzle 34 (see FIG. 3) of the recording head 6 while being relatively moved, and the ink is landed on the recording medium S to record an image or the like. It is also possible to adopt a configuration in which the ink cartridge 17 is disposed on the main body side of the printer, and the ink of the ink cartridge 17 is sent to the recording head 6 side through a supply tube.

  The printer controller 7 is a control unit that controls each part of the printer. The printer controller 7 in the present embodiment includes an interface (I / F) unit 8, a control unit 9, a storage unit 10, and a drive signal generation unit 11. The interface unit 8 transmits / receives printer status data when sending print data or a print command from the external device 2 to the printer 1 or outputting status information of the printer 1 to the external device 2 side. The control unit 9 is an arithmetic processing device for controlling the entire printer. The memory | storage part 10 is an element which memorize | stores the data used for the program and various control of the control part 9, and contains ROM, RAM, and NVRAM (nonvolatile memory element). The control unit 9 controls each unit according to a program stored in the storage unit 10. In addition, the control unit 9 according to the present embodiment generates ejection data indicating at which timing from which nozzle 34 of the recording head 6 the ink is ejected based on the print data from the external apparatus 2 and the ejection. Data is transmitted to the head controller 15 of the recording head 6. The drive signal generation unit 11 (drive waveform generation means) generates an analog signal based on waveform data relating to the waveform of the drive signal, and amplifies the signal to generate the drive signal COM shown in FIG.

  Next, the print engine 13 will be described. As shown in FIG. 1, the print engine 13 includes a paper feed mechanism 3, a carriage moving mechanism 4, a linear encoder 5, a recording head 6, and the like. The carriage moving mechanism 4 includes a carriage 16 to which a recording head 6 that is a kind of liquid ejecting head is attached, a drive motor (for example, a DC motor) that drives the carriage 16 via a timing belt or the like (see FIG. The recording head 6 mounted on the carriage 16 is moved in the main scanning direction. The paper feed mechanism 3 includes a paper feed motor, a paper feed roller, and the like, and sequentially feeds the recording medium S onto the platen to perform sub-scanning. Further, the linear encoder 5 outputs an encoder pulse corresponding to the scanning position of the recording head 6 mounted on the carriage 16 to the printer controller 7 as position information in the main scanning direction. The control unit 9 of the printer controller 7 can grasp the scanning position (current position) of the recording head 6 based on the encoder pulse received from the linear encoder 5 side. Further, the control unit 9 generates a timing signal (latch signal LAT) that defines the generation timing of a drive signal COM described later based on the encoder pulse.

FIG. 3 is a cross-sectional view of a main part for explaining the internal configuration of the recording head 6.
The recording head 6 in the present embodiment includes a case 20, a vibrator unit 21 housed in the case 20, a flow path unit 22 joined to the bottom surface (tip surface) of the case 20, and the like. Yes. The case 20 is made of, for example, an epoxy resin, and a housing empty portion 23 for housing the vibrator unit 21 is formed therein. The vibrator unit 21 includes a piezoelectric element 24 that functions as a kind of pressure generating means, a fixing plate 25 to which the piezoelectric element 24 is joined, and a flexible cable 26 for supplying a drive signal and the like to the piezoelectric element 24. ing. The piezoelectric element 24 is a laminated type produced by cutting a piezoelectric plate in which piezoelectric layers and electrode layers are alternately laminated into a comb-like shape, and is so-called longitudinal vibration mode capable of expanding and contracting in a direction perpendicular to the lamination direction. This is a piezoelectric vibrator.

  The flow path unit 22 is configured by joining a nozzle plate 28 to one surface of the flow path forming substrate 27 and a diaphragm 29 to the other surface of the flow path forming substrate 27. The flow path unit 22 is provided with a reservoir 30 (common liquid chamber), an ink supply port 31, a pressure chamber 32, a nozzle communication port 33, and a nozzle 34. A series of ink flow paths (corresponding to the liquid flow paths in the present invention) from the ink supply port 31 to the nozzle 34 through the pressure chamber 32 and the nozzle communication port 33 are formed corresponding to each nozzle 34. . The nozzle plate 28 is a thin plate made of a metal such as stainless steel or a silicon single crystal substrate in which a plurality of nozzles 34 are formed in rows at a pitch corresponding to the dot formation density. The nozzle plate 28 is provided with a plurality of nozzle rows 34 (nozzle rows), and one nozzle row is composed of, for example, 180 nozzles 34.

  The diaphragm 29 has a double structure in which an elastic film 37 is laminated on the surface of the support plate 36. In the present embodiment, a stainless plate, which is a kind of metal plate, is used as the support plate 36, and the vibration plate 29 is configured by a composite plate material in which a resin film is laminated as an elastic film 37 on the surface of the support plate 36. The diaphragm 29 is provided with a diaphragm portion 38 that changes the volume of the pressure chamber 32. The diaphragm 29 is provided with a compliance portion 39 that seals a part of the reservoir 30.

  The diaphragm portion 38 is produced by partially removing the support plate 36 by etching or the like. That is, the diaphragm portion 38 includes an island portion 40 to which the front end surface of the piezoelectric element 24 is joined, and a thin elastic portion surrounding the island portion 40. The compliance part 39 is produced by removing the support plate 36 in the region facing the opening surface of the reservoir 30 by etching or the like in the same manner as the diaphragm part 38, and the pressure fluctuation of the liquid stored in the reservoir 30 is reduced. Functions as a damper to absorb.

  Since the tip surface of the piezoelectric element 24 is joined to the island portion 40, the volume of the pressure chamber 32 can be changed by expanding and contracting the piezoelectric element 24. A pressure fluctuation occurs in the ink in the pressure chamber 32 in accordance with the volume fluctuation. The recording head 6 ejects ink droplets from the nozzles 34 using this pressure fluctuation.

  FIG. 4 is a waveform diagram illustrating an example of the configuration of the drive signal COM generated by the drive signal generation unit 11. The drive signal COM is repeatedly generated from the drive signal generation unit 11 for each unit period T defined by the latch signal LAT generated according to the scan of the recording head 6. The unit period T corresponds to a period during which the nozzle 34 moves by a distance corresponding to one pixel such as an image to be printed on the recording medium S, for example. In the present embodiment, this unit period T is determined by the first period T1, the second period T2, the third period T3, and the fourth period T4 by the change signal CH generated based on the latch signal LAT. There are a total of four periods. In the first period T1, the vibration drive pulse VP, in the second period T2, the first injection drive pulse DP1, in the third period T3, the second injection drive pulse DP2, and in the fourth period T4. A third ejection drive pulse DP3 is generated respectively. During the printing process, when the recording head 6 moves in a section corresponding to the recording area on the recording medium S, the piezoelectric element 24 provided in each pressure chamber 32 receives a drive pulse of the drive signal COM. At least one of them is selectively applied. Specifically, when the recording head 6 moves in a section corresponding to the recording area, the ejection drive pulses DP1 to DP1 are applied to the piezoelectric element 24 corresponding to the nozzle 34 that ejects ink at a predetermined cycle. Any of DP3 is selected and applied (this selection control will be described later). On the other hand, the vibration drive pulse VP is applied to the piezoelectric element 24 corresponding to the nozzle 34 to which ink is not ejected at a predetermined period in the section corresponding to the recording area, and the pressure chamber 32 and the nozzle are not ejected from the nozzle 34. The ink in 34 is vibrated (slightly vibrated). Note that the shapes of the vibration drive pulse VP and the ejection drive pulses DP1 to DP3 are not limited to those illustrated, and those having various waveforms are employed depending on the amount of ink ejected from the nozzles 34 and the like.

  FIG. 5 is a waveform diagram for explaining the configuration of the ejection drive pulses DP1 to DP3. In order to make the difference between the waveforms easier to understand, these drive pulses are shown in a superimposed manner. The ejection drive pulses DP1 to DP3 are all drive pulses for ejecting ink from the nozzles 34 (corresponding to the drive waveform in the present invention). In the present embodiment, these ejection drive pulses DP1 to DP3 are set so that the voltages (potential difference from the lowest potential to the highest potential) are different from each other. Specifically, the voltage V2 of the second ejection drive pulse DP2 is set larger than the voltage V1 of the first ejection drive pulse DP1. Further, the voltage V3 of the third ejection drive pulse DP3 is set to be larger than the voltage V1 of the first ejection drive pulse DP1. That is, the voltages of these ejection drive pulses DP1 to DP3 have a relationship of V3 <V1 <V2. The higher the ejection drive pulse voltage, the higher the flying speed Vm of ink ejected from the nozzles 34 and the ink weight Iw. The lower the ejection drive pulse voltage, the greater the ejection speed Vm of ink ejected from the nozzles 34 and the ink. The weight Iw decreases. Therefore, the second ejection drive pulse DP2 is a drive waveform set so that the flying speed of the ink ejected from the nozzles 34 is higher than that in the case of the first ejection drive pulse DP1, and the third ejection drive pulse DP2. DP3 is a drive waveform set so that the flying speed of the ink ejected from the nozzles 34 is lower than that in the case of the first ejection drive pulse DP1.

  Here, FIG. 6 shows the number of ejections (horizontal axis) when ink is ejected from the same nozzle 34 a plurality of times using the same ejection driving pulse, and the flying speed of the ink ejected from the nozzle 34. It is a graph which shows the relationship with Vm (vertical axis). As shown in the figure, with respect to the flying speed Vm1 of the ink ejected during the first ejection (or when the ejection is single), the ink from the second to the nth Flight speed is reduced. On the other hand, after the (n + 1) th shot, the ink flying speed is higher than the flying speed Vm1. Note that n differs depending on the characteristics of the flow path of the recording head 6 (flow path resistance, inertance, etc.), ink composition, and environmental conditions (temperature and humidity). In some cases, n = 2. That is, only the flying speed of the second ink may be lower than the flying speed Vm1.

  Such a phenomenon is considered to occur for the following reason. That is, when the first ink is ejected from the state where the ink in the individual flow path from the ink supply port 31 in the recording head 6 through the pressure chamber 32 to the nozzle 34 is substantially stationary, this ejection is performed. The volume of ink in the pressure chamber 32 is reduced by the amount of ink. However, the supply of ink from the ink supply port 31 to the pressure chamber 32 does not catch up due to the viscous resistance of the ink in a stationary state, thereby reducing the internal pressure of the pressure chamber 32 and causing the meniscus in the nozzle 34 to It will be in the state pulled in to the pressure chamber 32 side rather than time. In a state where the meniscus is drawn to the pressure chamber 32 side than usual, the behavior of the meniscus changes according to the pressure fluctuation, and it becomes difficult to eject ink than usual. When ink is ejected continuously, the second and subsequent shots are ejected in a state where the meniscus is drawn. Therefore, the flying speed of the ink ejected from the nozzle 34 is the first shot until the nth. It will be lower than the flight speed Vm1. On the other hand, when the ink in the individual flow path starts to flow as ink ejection continues, the amount of ink supplied from the ink supply port to the pressure chamber 32 increases, and the overall position of the meniscus at the nozzle 34 also increases. More on the injection side than at the first shot. As a result, after the (n + 1) th shot, the flying speed of the ink ejected from the nozzle 34 increases compared to the first flying speed Vm1.

  Therefore, in the printer 1 according to the present invention, when ink is continuously ejected from the same nozzle 34, any one of the ejection drive pulses DP1 to DP3 is selected and applied to the piezoelectric element 24 according to the number of ejections. By performing the control, the flying speed of the ink when continuously ejected is made constant (the flying speed is Vm1). Specifically, when the first ejection is performed, the first ejection drive pulse DP1 is selected from the drive signal COM and applied to the piezoelectric element 24 corresponding to the nozzle 34. Thereby, the flying speed of the ink ejected from the nozzle 34 becomes Vm1. When performing the second to n-th injections, the second injection drive pulse DP2 is selected from the drive signal COM and applied to the piezoelectric element 24. The second ejection drive pulse DP2 is set so as to increase the flying speed of the ejected ink as compared with the case of the first ejection drive pulse DP1, and therefore, the same ejection drive pulse as the first shot is used. Compared to the case, the flight speed from the second to the nth shot increases. Thereby, as shown by the upward arrow in FIG. 6, the flight speed from the second to the nth flight can be made closer to the first flight speed Vm1. Similarly, when performing the (n + 1) th and subsequent injections, the third injection drive pulse DP3 is selected from the drive signal COM and applied to the piezoelectric element 24. The third ejection driving pulse DP3 is set so that the flying speed of the ejected ink is lower than that in the case of the first ejection driving pulse DP1, and therefore the same ejection driving pulse as the first ejection is used. Compared with the case of using, the flight speed after the (n + 1) th shot is lowered. Thereby, as shown by the downward arrow in FIG. 6, the flight speed after the (n + 1) th shot can be made closer to the first flight speed Vm1. When ink is ejected at a predetermined unit period T and then a period in which ink is not ejected (rest period) continues for a predetermined period or longer, the next ejection of ink is performed when the first ejection drive pulse DP1 is generated. Selected. For example, when the time until the ink flow or vibration in the ink flow path is almost settled is set as a threshold value, and the threshold value is exceeded, the first ejection drive pulse DP1 is selected at the next first first ejection. The

  As described above, in the printer 1 according to the present invention, the ejection characteristics such as the flying speed and amount (weight / volume) of the ejected ink are uniform regardless of the number of ejections when ejecting the ink continuously. Thereby, it is possible to suppress the deviation of the landing position of ink on the recording medium S and the variation in dot size. In this embodiment, since the flying speeds are made uniform by changing the voltages V1 to V3 of the ejection driving pulses DP1 to DP3, the ink liquid amount changes with the change of the ink flying speed. Even in this case, regardless of the number of times of ejection, the amount of ejected ink can be brought close to the first first amount.

  In addition, this invention is not limited to each above-mentioned embodiment, A various deformation | transformation is possible based on description of a claim.

  FIG. 7 is a waveform diagram illustrating the configuration of the ejection drive pulses DP1 to DP3 in the second embodiment of the present invention. In the first embodiment, the configuration in which the voltages V1 to V3 of the ejection drive pulses DP1 to DP3 are made different is illustrated. However, in the present embodiment, the voltages of the ejection drive pulses DP1 to DP3 are made constant (V). In the first embodiment, the slope (V / Δt) of the waveform element p for driving the piezoelectric element 24 is made to be different for each ejection drive pulse so that the pressure chamber 32 is contracted to eject ink from the nozzle 34. It is different from the form. The slope of the waveform element is the rate of change of the potential, and becomes steeper as the rate of change increases. The slope of the waveform element p of the first ejection drive pulse DP1 is G1, the slope of the waveform element p of the second ejection drive pulse DP2 is G2, and the slope of the waveform element p of the third ejection drive pulse DP3 is G3. Is set so that | G3 | <| G1 | <| G2 |. The steep inclination of the waveform element p increases the flying speed Vm of the ink ejected from the nozzle 34, and the gentler the inclination of the waveform element p, the lower the flying speed Vm of the ink ejected from the nozzle 34. To do. Therefore, as in the first embodiment, the second ejection drive pulse DP2 is a drive set so that the flying speed of the ink ejected from the nozzles 34 is higher than in the case of the first ejection drive pulse DP1. The third ejection drive pulse DP3 is a waveform that is set such that the flying speed of the ink ejected from the nozzles 34 is lower than that in the case of the first ejection drive pulse DP1. Also in the present embodiment, when ink is continuously ejected from the same nozzle 34, control is performed to select any one of the ejection drive pulses DP1 to DP3 and apply it to the piezoelectric element 24 according to the number of ejections. Thus, it is possible to make the flying speed of ink when ejected continuously constant (flying speed Vm1). Further, by changing the slope of the waveform element p in a state where the voltage is constant, it is possible to change the flying speed while maintaining the liquid amount of the ink ejected from the nozzle 34 constant. For this reason, in the case where the ink liquid amount hardly changes even if the ink flying speed changes, the flying speed can be brought close to the first flying speed while the liquid amount is kept constant.

In the above embodiment, the so-called longitudinal vibration type piezoelectric element 24 is exemplified as the pressure generating means. However, the present invention is not limited to this, and for example, a so-called flexural vibration type piezoelectric element can be employed. In this case, the drive pulse DP illustrated in the above embodiment has a waveform in which the direction of potential change, that is, up and down is inverted.
In addition, the pressure generating means is not limited to the piezoelectric element, and various pressure generating means such as a heat generating element that generates bubbles in the pressure chamber and an electrostatic actuator that changes the volume of the pressure chamber using electrostatic force are used. The present invention can also be applied.

  And, the present invention is not limited to a printer, as long as it is a liquid ejecting apparatus that ejects liquid in a liquid flow path by applying a drive pulse to a pressure generating means, and a plotter, a facsimile machine, a copier, etc. The present invention can also be applied to various ink jet recording apparatuses or textile printing apparatuses that perform printing by landing ink from a liquid ejecting head on a cloth (printing material) that is a kind of landing target.

DESCRIPTION OF SYMBOLS 1 ... Printer, 6 ... Recording head, 9 ... Control part, 11 ... Drive signal production | generation part, 24 ... Piezoelectric element, 31 ... Ink supply port, 32 ... Pressure chamber, 34 ... Nozzle

Claims (4)

A nozzle for ejecting liquid and pressure generating means for causing pressure fluctuations in the liquid in a liquid flow path communicating with the nozzle are provided, and the liquid is ejected from the nozzle by driving the pressure generating means by applying a driving waveform. A liquid jet head
Compared to the case of the first drive waveform, the second drive waveform set so that the flying speed of the liquid ejected from the nozzle is higher than that of the first drive waveform, and the case of the first drive waveform. And a third drive waveform set so that the flying speed of the liquid ejected from the nozzle is reduced, and is selectable.
In the case where liquid is continuously ejected from the nozzle, the first first ejection is performed using the first driving waveform, and the second to nth ejections are performed using the second driving waveform. A liquid ejecting apparatus that performs ejection and performs ejection after the (n + 1) th ejection using the third driving waveform.   The voltage of the first drive waveform is V1, the voltage of the second drive waveform is V2, and the voltage of the third drive waveform is V3, V3 <V1 <V2. Item 2. The liquid ejecting apparatus according to Item 1. The first drive waveform, the second drive waveform, and the third drive waveform are waveform elements that drive the pressure generating means to increase the pressure in the liquid flow path so that liquid is ejected from the nozzle. Each with
The change rate of the potential change of the waveform element in the first drive waveform is G1, the change rate of the potential change of the waveform element in the second drive waveform is G2, and the potential change of the waveform element in the third drive waveform. 2. The liquid ejecting apparatus according to claim 1, wherein when the change rate is G3, | G3 | <| G1 | <| G2 |. A nozzle for ejecting liquid and pressure generating means for causing pressure fluctuations in the liquid in a liquid flow path communicating with the nozzle are provided, and the liquid is ejected from the nozzle by driving the pressure generating means by applying a driving waveform. A control method for a liquid ejecting apparatus including a liquid ejecting head,
Compared to the case of the first drive waveform, the second drive waveform set so that the flying speed of the liquid ejected from the nozzle is higher than that of the first drive waveform, and the case of the first drive waveform. The liquid can be ejected using the third driving waveform set so that the flying speed of the liquid ejected from the nozzle is reduced,
In the case where liquid is continuously ejected from the nozzle, the first first ejection is performed using the first driving waveform, and the second to nth ejections are performed using the second driving waveform. A method of controlling a liquid ejecting apparatus, comprising performing ejection and performing ejection after the (n + 1) th ejection using the third driving waveform.

Images