JP2009061671A - Liquid jet apparatus and printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jet apparatus and a printer, capable of reducing power consumption. <P>SOLUTION: A charging source potential pre-adjusting waveform signal WCCOM for pre-adjusting the potential of the charging source for a plurality of driving signal generation circuits 72 disposed corresponding to each of a plurality of nozzle groups is generated, and a pulse-modulated charging source potential modulation signal CPWM is power-amplified by a pair of charging source potential transistors 32 of a charging source potential digital power amplifier 28, then, the signal is smoothed and outputted to a collector of a charging transistor Tr1 of each driving signal generation circuit 72. And also, a discharge destination pre-adjusting waveform signal WDCOM for pre-adjusting the potential of the discharge destination from the plurality of driving signal generation circuits 72 is generated, and the pulse-modulated discharge destination modulation signal DPWN is power-amplified by a pair of discharge destination potential transistors 33 of a discharge destination potential digital power amplifier 29, then, the signal is smoothed and outputted to a collector of a discharge transistor Tr2 of each driving signal generation circuit 72. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a printing apparatus that prints predetermined characters, images, and the like by ejecting minute liquid from a plurality of nozzles and forming fine particles (dots) on a printing medium.

Inkjet printers, which are one of such printing devices, are generally inexpensive and can easily obtain high-quality color printed matter. Therefore, with the spread of personal computers and digital cameras, not only offices but also general users. It has become widespread.
Furthermore, recent inkjet printers require printing with high gradation. The gradation is a state of the density of each color contained in a so-called pixel represented by a liquid dot, and the size of the liquid dot corresponding to the density of the color of each pixel is called a gradation, and can be expressed by the liquid dot. The number of furniture is called the number of gradations. High gradation means that the number of gradations is large. In order to change the gradation, it is necessary to change the drive pulse to the actuator provided in the liquid ejecting head. When the actuator is a piezoelectric element, the amount of displacement (distortion) of the piezoelectric element (exactly the diaphragm) increases as the voltage value applied to the piezoelectric element increases. Can be changed.

  Therefore, in Patent Document 1 listed below, a plurality of drive pulses having different voltage peak values are combined and connected to generate a drive signal, which is common to the piezoelectric elements of the same color nozzle provided in the liquid ejecting head. The drive pulse corresponding to the gradation of the liquid dot to be formed is selected for each nozzle, and the selected drive pulse is supplied to the piezoelectric element of the corresponding nozzle to have a different weight. By ejecting the liquid, the required gradation of the liquid dots is achieved.

  However, in the conventional inkjet printer that drives the liquid ejecting head, one drive signal or drive pulse is applied to all the nozzle actuators. Even if a signal or a driving pulse is applied, the gradation of the liquid dots may be different. In the case of a line head type ink jet printer having a nozzle row corresponding to the width of the print medium for each color, the actuator is often manufactured for each nozzle row, so the difference in the gradation of liquid dots may occur for each nozzle row. Is expensive. Further, there is a possibility that a difference in gradation of liquid dots may occur for each nozzle row depending on the liquid characteristics of each color.

In order to solve such a problem, in the ink jet printer described in Patent Document 2 below, a plurality of drive signal generation circuits are provided for each nozzle row of different liquid colors to be ejected, and driving according to the liquid dot characteristics of the nozzle row A signal is generated and supplied to the actuator of the corresponding nozzle row.
Japanese Patent Laid-Open No. 10-81013 Japanese Patent Laid-Open No. 10-291310

  By the way, since the piezoelectric element used as the nozzle actuator of the inkjet printer is a charge / discharge actuator, the drive signal charges the charge / discharge actuator or discharges the charge from the charge / discharge actuator. The circuit configuration of the current amplifier in the drive signal generation circuit is composed of a charge transistor and a discharge transistor that are push-pull connected, and a drive signal is amplified by so-called linear drive using a high power supply potential. However, in the current amplifier having such a configuration, the potential difference between the power supply potential and the drive signal for charging the charge / discharge actuator and the potential difference between the drive signal discharged from the actuator and the ground potential are large, resulting in large power consumption. Since most of this power consumption is consumed as heat, each drive signal generation circuit requires a large transistor or heat sink, which requires a very large mounting area on the circuit board. Above, it becomes a big obstacle.

  The present invention can reduce the potential difference between the charge source potential preliminary adjustment signal and the drive signal charged to the charge / discharge actuator or the potential difference between the discharge destination potential preliminary adjustment signal and the drive signal discharged from the charge / discharge actuator, An object of the present invention is to provide a liquid ejecting apparatus and a printing apparatus that can reduce power consumption.

  In order to solve the above problems, a liquid ejecting apparatus according to a first aspect of the present invention includes a plurality of nozzles provided in a liquid ejecting head, a charge / discharge actuator provided corresponding to the nozzle, and a drive signal applied to the actuator. Each of a plurality of nozzle groups obtained by dividing the nozzles, and a drive waveform signal generating unit that generates a drive waveform signal serving as a reference of a signal for controlling the drive of the actuator. A plurality of drive signals for amplifying the drive waveform signal generated by the drive waveform signal generating means by the charge transistor and the discharge transistor connected to each other and push-pull connected, and outputting the drive signal toward the corresponding nozzle group Generating a charge source potential preliminary adjustment waveform signal for preliminarily adjusting the potential of the charge source to the generation means and the plurality of drive signal generation means Charge source potential preliminary adjustment waveform signal generating means, disposed between a charge source for the plurality of drive signal generation means and the drive signal generation means, and generated by the charge source potential preliminary adjustment waveform signal generation means Charging source potential preliminary adjusting means for preliminarily adjusting charging source potentials to the plurality of drive signal generating means based on a charging source potential preliminary adjusting waveform signal, wherein the charging source potential preliminary adjusting means includes the charging source potential preliminary adjusting means. Charge source potential modulation means for pulse modulating the charge source potential preliminary adjustment waveform signal generated by the adjustment waveform signal generation means, and pulse modulation by the charge source potential modulation means by push-pull connected charge source potential transistor pairs A charge source potential digital power amplifier for power amplifying the charged source potential modulation signal, and a charge source potential preliminary adjustment amplified by the charge source potential digital power amplifier. It is characterized in that a charging source potential smoothing filter for outputting a signal to the collector of the charging transistor of said driving signal generating means.

According to this liquid ejecting apparatus, the potential difference between the charge source potential preliminary adjustment signal and the drive signal for charging the charge / discharge actuator can be reduced, and the power consumption can be reduced.
In the liquid ejecting apparatus according to the aspect of the invention, the charging source potential preliminary adjustment waveform signal generating unit may perform charging in which the potential of the charging source potential preliminary adjustment signal is adjusted by adjusting a voltage value of the charging source potential preliminary adjustment signal. An original potential preliminary adjustment waveform signal is generated.

According to this liquid ejecting apparatus, it is possible to improve the accuracy of the drive signal and further reduce the power consumption.
In the liquid ejecting apparatus according to the aspect of the invention, the charging source potential preliminary adjustment waveform signal generation unit may adjust the potential of the charging source potential preliminary adjustment signal by adjusting the phase of the charging source potential preliminary adjustment signal. A potential pre-adjustment waveform signal is generated.
According to this liquid ejecting apparatus, it is possible to improve the accuracy of the drive signal and further reduce the power consumption.

In the liquid ejecting apparatus according to the aspect of the invention, the drive waveform signal generation unit may generate a plurality of drive waveform signals having different waveforms corresponding to the plurality of nozzle groups obtained by dividing the nozzle, and the charging source It is characterized in that the potential of the potential preliminary adjustment signal is set higher than the potential during the charging period of all the drive signals output toward the corresponding nozzle group.
According to this liquid ejecting apparatus, it is possible to reduce variations in gradation of liquid dots caused by differences in individual nozzles due to differences in ink characteristics and actuator drive characteristics, and to further reduce power consumption.

  In addition, the liquid ejecting apparatus of the invention includes a plurality of nozzles provided in the liquid ejecting head, a charge / discharge type actuator provided corresponding to the nozzle, and a driving unit that applies a driving signal to the actuator. And a push-pull provided in each of a drive waveform signal generating means for generating a drive waveform signal serving as a reference of a signal for controlling the drive of the actuator and a plurality of nozzle groups into which the nozzles are divided. A plurality of driving signal generating means for amplifying the driving waveform signal generated by the driving waveform signal generating means by the connected charging transistor and discharging transistor and outputting a driving signal toward a corresponding nozzle group; Discharge destination potential pre-adjustment wave for generating a discharge destination potential pre-adjustment waveform signal for pre-adjusting the discharge destination potential of the drive signal generating means Discharge destination potential preliminary adjustment waveform that is disposed between the signal generation means, the discharge destination from the plurality of drive signal generation means and the drive signal generation means, and generated by the discharge destination potential preliminary adjustment waveform signal generation means Discharge destination potential preliminary adjustment means for preliminarily adjusting discharge destination potentials from the plurality of drive signal generation means based on a signal, wherein the discharge destination potential preliminary adjustment means is the discharge destination potential preliminary adjustment waveform signal generation means. Discharge destination potential modulation means for pulse-modulating the generated discharge destination potential preliminary adjustment waveform signal, and discharge destination potential pulse-modulated by the discharge destination potential modulation means by a push-pull connected discharge destination potential transistor pair A discharge destination potential digital power amplifier for power amplification of the modulation signal, and a discharge destination potential preliminary adjustment signal amplified by the discharge destination potential digital power amplifier as the drive signal. It is characterized in that a discharge destination potential smoothing filter for outputting to the collector of the discharge transistor of the generator.

According to this liquid ejecting apparatus, the potential difference between the discharge destination potential preliminary adjustment signal and the drive signal discharged from the charge / discharge actuator can be reduced, and the power consumption can be reduced.
In the liquid ejecting apparatus according to the aspect of the invention, the discharge destination potential preliminary adjustment waveform signal generation unit may adjust the voltage value of the discharge destination potential preliminary adjustment signal to adjust the potential of the discharge destination potential preliminary adjustment signal. A pre-potential pre-adjustment waveform signal is generated.

According to this liquid ejecting apparatus, it is possible to improve the accuracy of the drive signal and further reduce the power consumption.
In the liquid ejecting apparatus of the invention, the discharge destination potential preliminary adjustment waveform signal generating unit adjusts the phase of the discharge destination potential preliminary adjustment signal to adjust the potential of the discharge destination potential preliminary adjustment signal. A potential pre-adjustment waveform signal is generated.
According to this liquid ejecting apparatus, it is possible to improve the accuracy of the drive signal and further reduce the power consumption.

In the liquid ejecting apparatus according to the aspect of the invention, the drive waveform signal generating unit may generate a plurality of drive waveform signals having different waveforms corresponding to the plurality of nozzle groups obtained by dividing the nozzle, and the discharge destination It is characterized in that the potential of the potential preliminary adjustment signal is set lower than the potential during the discharge period of all the drive signals output toward the corresponding nozzle group.
According to this liquid ejecting apparatus, it is possible to reduce variations in gradation of liquid dots caused by differences in individual nozzles due to differences in ink characteristics and actuator drive characteristics, and to further reduce power consumption.

  In addition, the liquid ejecting apparatus of the invention includes a plurality of nozzles provided in the liquid ejecting head, a charge / discharge type actuator provided corresponding to the nozzle, and a driving unit that applies a driving signal to the actuator. And a push-pull provided in each of a drive waveform signal generating means for generating a drive waveform signal serving as a reference of a signal for controlling the drive of the actuator and a plurality of nozzle groups into which the nozzles are divided. A plurality of driving signal generating means for amplifying the driving waveform signal generated by the driving waveform signal generating means by the connected charging transistor and discharging transistor and outputting a driving signal toward a corresponding nozzle group; Charge source potential pre-adjustment for generating a charge source potential pre-adjustment waveform signal for pre-adjusting the charge source potential to the drive signal generating means Pre-adjustment of charge source potential generated by the charge source potential pre-adjustment waveform signal generation means and disposed between the shape signal generation means, the charge source for the plurality of drive signal generation means and the drive signal generation means Charge source potential preliminary adjustment means for preliminarily adjusting charge source potentials to the plurality of drive signal generation means based on a waveform signal, and discharge destination potential for preliminary adjustment of discharge destination potentials of the plurality of drive signal generation means Discharge destination potential pre-adjustment waveform signal generating means for generating a pre-adjustment waveform signal, and a discharge destination potential pre-adjustment waveform disposed between a discharge destination from the plurality of drive signal generation means and the drive signal generation means. Discharge destination potential preliminary adjustment means for preliminarily adjusting discharge destination potentials from the plurality of drive signal generation means based on a discharge destination potential preliminary adjustment waveform signal generated by the signal generation means, and the charge source potential The charge adjustment means includes a charge source potential modulation means for pulse-modulating the charge source potential preliminary adjustment waveform signal generated by the charge source potential preliminary adjustment waveform signal generation means, and a charge source potential transistor pair that is push-pull connected. A charging source potential digital power amplifier that amplifies the power of the charging source potential modulation signal pulse-modulated by the charging source potential modulation means, and a charging source potential preliminary adjustment signal amplified by the charging source potential digital power amplifier Is supplied to the collector of the charging transistor of the drive signal generation means, and the discharge destination potential preliminary adjustment means is a discharge destination generated by the discharge destination potential preliminary adjustment waveform signal generation means. The discharge destination potential modulation means for pulse-modulating the potential pre-adjustment waveform signal, and the discharge destination potential transistor pair connected in a push-pull manner. A discharge destination potential digital power amplifier that amplifies the power of the discharge destination potential modulation signal pulse-modulated by the discharge destination potential modulation means, and a discharge destination potential preliminary adjustment signal amplified by the discharge destination potential digital power amplifier. And a discharge destination potential smoothing filter that outputs to the collector of the discharge transistor of the drive signal generating means.

According to this liquid ejecting apparatus, the potential difference between the charge source potential preliminary adjustment signal and the drive signal for charging the charge / discharge actuator can be reduced, and the discharge from the discharge destination potential preliminary adjustment signal and the charge / discharge actuator is discharged. The potential difference from the signal can be reduced, and power consumption can be reduced.
In the liquid ejecting apparatus according to the aspect of the invention, the charging source potential preliminary adjustment waveform signal generating unit may perform charging in which the potential of the charging source potential preliminary adjustment signal is adjusted by adjusting a voltage value of the charging source potential preliminary adjustment signal. A discharge for generating an original potential preliminary adjustment waveform signal, and the discharge destination potential preliminary adjustment waveform signal generating means adjusts the voltage value of the discharge destination potential preliminary adjustment signal to adjust the potential of the discharge destination potential preliminary adjustment signal. A pre-potential pre-adjustment waveform signal is generated.
According to this liquid ejecting apparatus, it is possible to improve the accuracy of the drive signal and further reduce the power consumption.

In the liquid ejecting apparatus according to the aspect of the invention, the charging source potential preliminary adjustment waveform signal generation unit may adjust the potential of the charging source potential preliminary adjustment signal by adjusting the phase of the charging source potential preliminary adjustment signal. A discharge destination potential preliminary adjustment waveform signal is generated, and the discharge destination potential preliminary adjustment waveform signal generating means adjusts the phase of the discharge destination potential preliminary adjustment signal to adjust the potential of the discharge destination potential preliminary adjustment signal. A pre-adjusted waveform signal is generated.
According to this liquid ejecting apparatus, it is possible to improve the accuracy of the drive signal and further reduce the power consumption.

The drive waveform signal generating means generates a plurality of drive waveform signals having different waveforms corresponding to each of a plurality of nozzle groups into which the nozzles are divided, and the potential of the charge source potential preliminary adjustment signal corresponds to the corresponding one. All the drive signals output to the nozzle group are set higher than the potential during the charging period, and the potential of the discharge destination potential preliminary adjustment signal is set to all the drive signals output to the corresponding nozzle group. It is characterized by being set lower than the potential during the discharge period.
According to this liquid ejecting apparatus, it is possible to reduce variations in gradation of liquid dots caused by differences in individual nozzles due to differences in ink characteristics and actuator drive characteristics, and to further reduce power consumption.

  In addition, the liquid ejecting apparatus of the invention includes a plurality of nozzles provided in the liquid ejecting head, a charge / discharge type actuator provided corresponding to the nozzle, and a driving unit that applies a driving signal to the actuator. And a push-pull provided in each of a drive waveform signal generating means for generating a drive waveform signal serving as a reference of a signal for controlling the drive of the actuator and a plurality of nozzle groups into which the nozzles are divided. A plurality of driving signal generating means for amplifying the driving waveform signal generated by the driving waveform signal generating means by the connected charging transistor and discharging transistor and outputting a driving signal toward a corresponding nozzle group; The charging source and discharge for preconditioning the potential of the charging source to the driving signal generating means and the potential of the discharging destination from the driving signal generating means. Charge source and destination potential pre-adjustment waveform signal generating means for generating a pre-potential pre-adjustment waveform signal, a charge source for the plurality of drive signal generation means, a discharge destination from the drive signal generation means, and the drive signal generation means And charge source potentials to the plurality of drive signal generating means based on the charge source and discharge destination potential preliminary adjustment waveform signal generated by the charge source and discharge destination potential preliminary adjustment waveform signal generating means. And a charge source and discharge destination potential preliminary adjustment means for preliminarily adjusting the discharge destination potential from the drive signal generating means, wherein the charge source and discharge destination potential preliminary adjustment means are the charge source and discharge destination potential preliminary adjustment waveforms. Charge source and discharge destination potential modulation means for pulse modulating the charge source and discharge destination potential preliminary adjustment waveform signals generated by the signal generation means, and for charge source and discharge destination potentials that are push-pull connected Charge source and discharge destination potential digital power amplifier that amplifies the charge source and discharge destination potential modulation signal pulse-modulated by the charge source and discharge destination potential modulation means by a pair of transistors, and the charge source and discharge destination potentials A charge source and discharge destination potential smoothing filter for outputting the charge source and discharge destination potential preliminary adjustment signals amplified by the digital power amplifier to the collector of the charge transistor and the collector of the discharge transistor of the drive signal generating means; It is characterized by having.

According to this liquid ejecting apparatus, the potential difference between the charge source / discharge destination potential preliminary adjustment signal and the drive signal for charging / discharging the charge / discharge actuator can be reduced, and the power consumption can be reduced.
In the liquid ejecting apparatus according to the aspect of the invention, the charge source and discharge destination potential preliminary adjustment waveform signal generation unit may adjust the voltage values of the charge source and discharge destination potential preliminary adjustment signals to adjust the charge source and discharge destination potentials. A charge source and discharge destination potential preliminary adjustment waveform signal for adjusting the potential of the preliminary adjustment signal is generated.
According to this liquid ejecting apparatus, it is possible to improve the accuracy of the drive signal and further reduce the power consumption.

In the liquid ejecting apparatus according to the aspect of the invention, the charge source and discharge destination potential preliminary adjustment waveform signal generating unit may adjust the phase of the charge source and discharge destination potential preliminary adjustment signal to adjust the charge source and discharge destination potential preliminary. A charge source and discharge destination potential preliminary adjustment waveform signal for adjusting the potential of the adjustment signal is generated.
According to this liquid ejecting apparatus, it is possible to improve the accuracy of the drive signal and further reduce the power consumption.

Moreover, the printing apparatus of the present invention is a printing apparatus including the above-described liquid ejecting apparatus.
According to this printing apparatus, the potential difference between the charge source potential preliminary adjustment signal and the drive signal that charges the charge / discharge actuator is reduced, or the potential difference between the discharge destination potential preliminary adjustment signal and the drive signal that is discharged from the charge / discharge actuator. As a result, the power consumption can be reduced, the drive signal accuracy can be improved, and the power consumption can be further reduced.

Next, as an example of the present invention, a first embodiment will be described with reference to the drawings using a printing apparatus that ejects liquid and prints characters, images, and the like on a print medium.
FIG. 1 is a schematic configuration diagram of a printing apparatus of the present embodiment, FIG. 1a is a plan view thereof, and FIG. 1b is a front view thereof. In FIG. 1, a print medium 1 is a line head type printing apparatus that is transported in the direction of the arrow in the drawing from the right to the left in the drawing and is printed in a printing area in the middle of the conveyance. However, the liquid jet head according to the present embodiment is arranged not only at one place but also at two places.

  In the figure, reference numeral 2 denotes a first liquid ejecting head provided on the upstream side in the transport direction of the print medium 1, and reference numeral 3 denotes a second liquid ejecting head also provided on the downstream side, and the first liquid ejecting head 2. A first transport unit 4 for transporting the print medium 1 is provided below the second liquid ejecting head 3, and a second transport unit 5 is provided below the second liquid ejecting head 3. The first transport unit 4 includes four first transport belts 6 arranged at predetermined intervals in a direction intersecting with the transport direction of the print medium 1 (hereinafter also referred to as nozzle row direction). Similarly, the second transport unit 5 includes four second transport belts 7 arranged at predetermined intervals in a direction (nozzle row direction) intersecting the transport direction of the print medium 1.

  The four second conveyor belts 7 as well as the four first conveyor belts 6 are arranged alternately adjacent to each other. In the present embodiment, among these conveyor belts 6, 7, two first conveyor belts 6 and 2 on the right side in the nozzle row direction and two first conveyor belts 6 and second on the left side in the nozzle row direction. The conveyor belt 7 is separated. That is, the right driving roller 8R is disposed in the overlapping portion of the two first conveyance belts 6 and the second conveyance belt 7 on the right side in the nozzle row direction, and the two first conveyance belts 6 and the second conveyance belts on the left side in the nozzle row direction. 7 is provided with a left driving roller 8L, a right first driven roller 9R and a left first driven roller 9L on the upstream side, and a right second driven roller 10R and a second left side on the downstream side. A driven roller 10L is provided. These rollers appear as a series, but are substantially divided at the central portion of FIG. 1a.

  The two first conveying belts 6 on the right side in the nozzle row direction are wound around the right driving roller 8R and the first driven roller 9R on the right side, and the two first conveying belts 6 on the left side in the nozzle row direction are connected to the left driving roller 8L and the left side. The two second conveying belts 7 on the right side in the nozzle row direction are wound around the first driven roller 9L, and the two second conveying belts on the left side in the nozzle row direction are wound on the right driving roller 8R and the second right driven roller 10R. 7 is wound around the left driving roller 8L and the second left driven roller 10L. The right electric motor 11R is connected to the right driving roller 8R, and the left electric motor 11L is connected to the left driving roller 8L. Accordingly, when the right driving roller 8R is rotationally driven by the right electric motor 11R, the first conveying unit 4 composed of the two first conveying belts 6 on the right side in the nozzle row direction and the two second conveying belts on the right side in the nozzle row direction. The second conveyance unit 5 configured by 7 moves in synchronization with each other at the same speed, and is configured by two first conveyance belts 6 on the left side in the nozzle row direction when the left driving roller 8L is rotationally driven by the left electric motor 11L. The second transport unit 5 including the first transport unit 4 and the two second transport belts 7 on the left side in the nozzle row direction are synchronized with each other and move at the same speed.

  However, if the rotation speeds of the right electric motor 11R and the left electric motor 11L are different, the conveyance speed in the left and right directions in the nozzle row can be changed. Specifically, the rotation speed of the right electric motor 11R is changed to that of the left electric motor 11L. When the rotational speed is higher than the rotation speed, the conveyance speed on the right side in the nozzle row direction can be made larger than that on the left side, and when the rotation speed of the left electric motor 11L is higher than the rotation speed of the right electric motor 11R. The speed can be greater than the right side.

  The first liquid ejecting head 2 and the second liquid ejecting head 3 are arranged in a color unit of yellow (Y), magenta (M), cyan (C), and black (K) while being shifted in the transport direction of the print medium 1. Has been. The liquid jet heads 2 and 3 are supplied with liquid from liquid tanks of respective colors (not shown) via liquid supply tubes. Each of the liquid jet heads 2 and 3 is formed with a plurality of nozzles in a direction crossing the transport direction of the print medium 1 (that is, the nozzle row direction). By ejecting, fine liquid dots are formed on the print medium 1. By performing this for each color, it is possible to perform printing in one pass only by passing the print medium 1 conveyed by the first conveyance unit 4 and the second conveyance unit 5 once. That is, the area where the liquid jet heads 2 and 3 are disposed corresponds to a printing area.

  As a method of ejecting liquid from each nozzle of the liquid ejecting head, there are an electrostatic method, a piezo method, a film boiling jet method, and the like. In the electrostatic system, when a drive signal is given to the electrostatic gap that is an actuator, the diaphragm in the cavity is displaced to cause a pressure change in the cavity, and the liquid is ejected from the nozzle by the pressure change. . In the piezo method, when a drive signal is given to a piezo element that is an actuator, the diaphragm in the cavity is displaced to cause a pressure change in the cavity, and the liquid is ejected from the nozzle by the pressure change. In the film boiling jet method, there is a micro heater in the cavity, and the liquid is instantaneously heated to 300 ° C or more, and the liquid becomes a film boiling state to generate bubbles, and the liquid is ejected from the nozzle by the pressure change. It is. The present invention can be applied to any liquid ejection method, but is particularly suitable for a piezo element that can adjust the liquid discharge amount by adjusting the peak value of the drive signal and the voltage increase / decrease slope. The piezo element is a so-called charge / discharge actuator having a capacity.

  The liquid ejecting nozzles of the first liquid ejecting head 2 are formed only between the four first transport belts 6 of the first transporting unit 4, and the liquid ejecting nozzles of the second liquid ejecting head 3 are second transported. It is formed only between the four second conveyor belts 7 of the section 5. This is because the liquid ejecting heads 2 and 3 are cleaned by a cleaning unit, which will be described later. However, if one of the liquid ejecting heads is used in this way, the entire surface printing cannot be performed in one pass. For this reason, the first liquid ejecting head 2 and the second liquid ejecting head 3 are arranged so as to be shifted in the transport direction of the print medium 1 in order to compensate for the portions that cannot be printed with each other.

  Disposed below the first liquid ejecting head 2 is the first cleaning cap 12 for cleaning the first liquid ejecting head 2 and disposed below the second liquid ejecting head 3. 2 is a second cleaning cap 13 for cleaning the liquid jet head 3. Each of the cleaning caps 12 and 13 has such a size that it can pass between the four first conveying belts 6 of the first conveying unit 4 and between the four second conveying belts 7 of the second conveying unit 5. It is formed. These cleaning caps 12 and 13 cover the nozzles formed on the lower surfaces of the liquid jet heads 2 and 3, that is, the nozzle surfaces, and are disposed at the bottoms of the rectangular bottomed cap bodies that can be in close contact with the nozzle surfaces. The liquid absorber, the tube pump connected to the bottom of the cap body, and a lifting device that lifts and lowers the cap body. Therefore, the cap body is raised by the lifting device and is brought into close contact with the nozzle surfaces of the liquid jet heads 2 and 3. In this state, when a negative pressure is applied to the inside of the cap by the tube pump, liquid and bubbles are sucked out from the nozzles provided on the nozzle surfaces of the liquid jet heads 2 and 3, and the liquid jet heads 2 and 3 can be cleaned. it can. When the cleaning is completed, the cleaning caps 12 and 13 are lowered.

  On the upstream side of the first driven rollers 9R and 9L, there are two pairs of gate rollers 14 that adjust the paper feed timing of the printing medium 1 supplied from the paper feeding unit 15 and correct the skew of the printing medium 1. Is provided. The skew is a twist of the print medium 1 with respect to the transport direction. A pickup roller 16 for supplying the print medium 1 is provided above the paper supply unit 15. Reference numeral 17 in the drawing denotes a gate roller motor that drives the gate roller 14.

  A belt charging device 19 is disposed below the drive rollers 8R and 8L. The belt charging device 19 includes a charging roller 20 that is in contact with the first conveying belt 6 and the second conveying belt 7 with the driving rollers 8R and 8L interposed therebetween, and the charging roller 20 is connected to the first conveying belt 6 and the second conveying belt 7. It comprises a spring 21 to be pressed and a power source 18 for applying a charge to the charging roller 20, and charges the first conveying belt 6 and the second conveying belt 7 from the charging roller 20 to charge them. In general, these belts are formed of a medium / high resistance body or an insulator, and when charged by the belt charging device 19, the charge applied to the surface thereof is also composed of a high resistance body or an insulator. The print medium 1 can be caused to generate dielectric polarization, and the print medium 1 can be adsorbed to the belt by electrostatic force generated between the charge generated by the dielectric polarization and the charge on the belt surface. Note that the belt charging device 19 may be a corotron or the like that reduces the charge.

  Therefore, according to this printing apparatus, the belt charging device 19 charges the surfaces of the first conveyance belt 6 and the second conveyance belt 7, and in this state, the printing medium 1 is fed from the gate roller 14, and a spur (not shown) When the printing medium 1 is pressed against the first conveying belt 6 by a paper pressing roller composed of a roller, the printing medium 1 is attracted to the surface of the first conveying belt 6 by the action of the dielectric polarization described above. In this state, when the driving rollers 8R and 8L are rotationally driven by the electric motors 11R and 11L, the rotational driving force is transmitted to the first driven rollers 9R and 9L via the first conveying belt 6.

  In this manner, the first transport belt 6 is moved downstream in the transport direction while the print medium 1 is adsorbed, the print medium 1 is moved below the first liquid ejecting head 2, and the first liquid ejecting head 2 is moved to the first liquid ejecting head 2. Printing is performed by ejecting liquid from the nozzles formed. When printing by the first liquid ejecting head 2 is completed, the print medium 1 is moved downstream in the transport direction and transferred to the second transport belt 7 of the second transport unit 5. As described above, since the surface of the second transport belt 7 is also charged by the belt charging device 19, the print medium 1 is attracted to the surface of the second transport belt 7 by the action of the dielectric polarization described above.

  In this state, the second conveying belt 7 is moved downstream in the conveying direction, the printing medium 1 is moved below the second liquid ejecting head 3, and the liquid is ejected from the nozzles formed in the second liquid ejecting head. And print. When printing by the second liquid ejecting head is completed, the print medium 1 is further moved downstream in the transport direction, and is discharged to the paper discharge unit while being separated from the surface of the second transport belt 7 by a separation device (not shown). Make paper.

  When the first and second liquid jet heads 2 and 3 need to be cleaned, the first and second liquid jet heads 2 and 3 are lifted by raising the first and second cleaning caps 12 and 13 as described above. The cap body is brought into close contact with the nozzle surface, and in that state, the cap body is set to a negative pressure so that liquids and bubbles are sucked out from the nozzles of the first and second liquid ejecting heads 2 and 3 for cleaning. The second cleaning caps 12 and 13 are lowered.

  A control device for controlling itself is provided in the printing apparatus. As shown in FIG. 2, the control device performs printing processing on a print medium by controlling a printing device, a paper feeding device, and the like based on print data input from a host computer 60 such as a personal computer or a digital camera. Is what you do. An input interface unit 61 that receives print data input from the host computer 60; a control unit 62 that includes a microcomputer that executes print processing based on the print data input from the input interface unit 61; A gate roller motor driver 63 for driving and controlling the roller motor 17, a pickup roller motor driver 64 for driving and controlling the pickup roller motor 51 for driving the pickup roller 16, and a head driver 65 for driving and controlling the liquid ejecting heads 2 and 3. The right electric motor driver 66R for driving and controlling the right electric motor 11R, the left electric motor driver 66L for driving and controlling the left electric motor 11L, and the output signals of the drivers 63 to 65, 66R and 66L as external gate roller motors. 7, the pickup roller motor 51, the liquid jet heads 2 and 3, the right electric motor 11R, configured to include an interface 67 for converting the drive signal used in the left side electric motor 11L.

  The control unit 62 temporarily stores a CPU (Central Processing Unit) 62a that executes various processes such as a print process, and print data input through the input interface 61 or various data when the print data print process is executed. A ROM (Read-Only ROM) comprising a RAM (Random Access Memory) 62c that temporarily stores an application program such as print processing or the like, and a non-volatile semiconductor memory that stores a control program executed by the CPU 62a Memory) 62d. When the control unit 62 obtains print data (image data) from the host computer 60 via the interface unit 61, the CPU 62a executes a predetermined process on the print data, and from which nozzle the liquid is ejected. Alternatively, print data (driving signal selection data SI & SP) indicating how much liquid is to be ejected is output, and control signals are sent to the drivers 63 to 65, 66R, and 66L based on the print data and input data from various sensors. Output. When control signals are output from the drivers 63 to 65, 66R, and 66L, these are converted into drive signals by the interface unit 67, and actuators corresponding to a plurality of nozzles of the liquid jet head, the gate roller motor 17, and the pickup roller motor. 51, the right electric motor 11R and the left electric motor 11L are operated, respectively, to feed and convey the print medium 1, control the posture of the print medium 1, and print processing on the print medium 1. Each component in the control unit 62 is electrically connected through a bus (not shown).

  The head driver 65 includes a drive waveform signal generation circuit 70 that forms a drive waveform signal WCOM, and a potential preliminary adjustment waveform signal generation circuit 71 that forms a charge source potential preliminary adjustment waveform signal WCCOM and a discharge destination potential preliminary adjustment waveform signal WDCOM. I have. As shown in FIG. 3, the drive waveform signal generation circuit 70 has a waveform data + ΔV1 at the rising timing of the clock signal from the state where the drive waveform signal WCOM is raised to the intermediate potential (offset) during the time width T1. The drive waveform signal WCOM is added one by one, and then the drive waveform signal WCOM is held at a constant value for the time width T0 (waveform data 0), and then for the time width T2, the waveform data −ΔV2 at the rising timing of the clock signal. The drive waveform signal WCOM is subtracted one by one. The drive waveform signal WCOM generated in this way is converted into an analog signal by the drive signal generation circuit 72 shown in FIG. 5 and is amplified to be supplied to the liquid jet heads 2 and 3 as the drive signal COM. An actuator such as a piezo element provided can be driven, and liquid can be ejected from each nozzle.

  The rising portion of the drive signal COM is a stage in which the volume of the cavity (pressure chamber) communicating with the nozzle is enlarged and the liquid is drawn (it can be said that the meniscus is drawn considering the liquid discharge surface), and the fall of the drive signal COM The portion is a stage in which the volume of the cavity is reduced to extrude the liquid (which can be said to extrude the meniscus in view of the liquid discharge surface), and as a result of extruding the liquid, the liquid is ejected from the nozzle. Incidentally, the waveform of the drive signal COM or the drive waveform signal WCOM can be adjusted by the waveform data 0, + ΔV1, −ΔV2, + ΔV3, and the clock signal for generating the drive waveform signal WCOM, as can be easily estimated from the foregoing. . In addition, since the piezo element is a capacitive load and is a so-called charge / discharge actuator, for example, in this embodiment, the charge / discharge actuator is charged at the rising portion of the drive signal COM and charged at the falling portion of the drive signal COM. Electric charges are discharged from the discharge actuator.

  By variously changing the voltage increase / decrease slope and peak value of the drive signal COM made up of this voltage trapezoidal wave, it is possible to change the amount of liquid drawn, the drawing speed, the amount of liquid extrusion, and the speed of extrusion. Different liquid dot sizes can be obtained by changing the discharge amount. Therefore, as shown in FIG. 4, a plurality of drive pulses PCOM are connected in time series to generate a drive signal COM, and a single drive pulse PCOM is selected and supplied to the actuator 22 such as a piezo element, Various liquid dot sizes can be obtained by ejecting liquid, selecting a plurality of drive pulses PCOM, supplying them to the actuator 22 such as a piezo element, and ejecting the liquid a plurality of times. That is, if a plurality of liquids land on the same position before the liquid dries, it is substantially the same as ejecting a large liquid, and the size of the liquid dots can be increased. It is possible to increase the number of gradations by combining such techniques. Note that the driving pulse PCOM1 at the left end in FIG. This is called microvibration and is used to suppress or prevent drying of the nozzle without discharging the liquid.

  As a result, the liquid ejecting heads 2 and 3 select the nozzle to be ejected based on the drive signal COM generated by the drive signal generation circuit 72 and the print data, and connect to the drive signal COM of an actuator such as a piezo element. The drive signal selection data signal SI & SP for determining the timing and the latch signal LAT for connecting the drive signal COM and the actuators of the liquid ejecting heads 2 and 3 based on the drive signal selection data SI & SP after the nozzle selection data is inputted to all the nozzles. The clock signal SCK for transmitting the channel signal CH and the drive signal selection data signal SI & SP to the liquid jet heads 2 and 3 as serial signals is input.

  Next, a configuration for connecting the drive signal COM output from the drive signal generation circuit and an actuator such as a piezoelectric element will be described. FIG. 6 is a block diagram of a selection unit that connects the drive signal COM and an actuator such as a piezo element. The selection unit includes a shift register 211 that stores drive signal selection data SI & SP for designating an actuator such as a piezo element corresponding to a nozzle that should eject liquid, and a latch circuit that temporarily stores data of the shift register 211. 212, a level shifter 213 for level-converting the output of the latch circuit 212, and a selection switch 201 for connecting the drive signal COM to the actuator 22 such as a piezo element in accordance with the output of the level shifter.

  The drive signal selection data signal SI & SP is sequentially input to the shift register 211, and the storage area is sequentially shifted from the first stage to the subsequent stage in accordance with the input pulse of the clock signal SCK. The latch circuit 212 latches each output signal of the shift register 211 by the input latch signal LAT after the drive signal selection data SI & SP for the number of nozzles is stored in the shift register 211. The signal stored in the latch circuit 212 is converted by the level shifter 213 to a voltage level at which the selection switch 201 at the next stage can be turned on / off. This is because the drive signal COM is higher than the output voltage of the latch circuit 212, and the operating voltage range of the selection switch 201 is set higher accordingly. Accordingly, an actuator such as a piezo element whose selection switch 201 is closed by the level shifter 213 is connected to the drive signal COM at the connection timing of the drive signal selection data SI & SP. In addition, after the drive signal selection data SI & SP of the shift register 211 is stored in the latch circuit 212, the next print information is input to the shift register 211, and the stored data in the latch circuit 212 is sequentially updated in accordance with the liquid ejection timing. . In addition, the code | symbol HGND in a figure is a ground end of actuators, such as a piezo element. Further, according to the selection switch 201, the input voltage of the actuator 22 is maintained at the voltage just before the disconnection even after the actuator such as the piezo element is disconnected from the drive signal COM.

  Returning to FIG. 5, in order to amplify the power of the drive signal COM as described above, a charge transistor and a discharge transistor that are push-pull connected as described later are disposed between the power source and the ground, and The push-pull connected transistor pair is linearly driven in accordance with the drive waveform signal WCOM. In the present embodiment, nozzle rows of color units with different actuator drive characteristics are used as nozzle groups, and a total of four drive signal generation circuits 72 are provided for each nozzle group. Thereby, since the drive signal generation circuit 72 is provided for each color unit, that is, for each nozzle row of the first and second liquid jet heads 2 and 3, the drive signal COM is adjusted according to the liquid jet characteristics of each nozzle row. It becomes possible to do. Specifically, the drive waveform signal WCOM to the drive signal generation circuit 72 for each color is adjusted, and the peak value and the voltage increase / decrease slope of each drive pulse constituting the drive signal COM are adjusted, so that each nozzle row This makes it possible to adjust the liquid ejection characteristics to a predetermined state.

  Further, a potential difference between a drive signal for charging a charge / discharge actuator such as a piezo element and a power supply potential (charge source potential), or a drive signal for discharging from the charge / discharge actuator and a ground potential (discharge destination potential) The potential difference obtained by multiplying the potential difference by the current value is the power consumption. As described above, the power consumption is almost consumed as heat. However, if the potential difference is large, the power consumption increases and the heat generation amount also increases. Therefore, in this embodiment, drive signal generation is performed in the potential preliminary adjustment circuits 26 and 27 based on the charge source potential preliminary adjustment waveform signal WCCOM and the discharge destination potential preliminary adjustment waveform signal WDCOM generated by the potential preliminary adjustment waveform signal generation circuit 71. By adjusting the charge source potential to the circuit 72 and the discharge destination potential from the drive signal generation circuit 72, the potential difference between the drive signal and the charge source potential for charging the charge / discharge actuator or the discharge from the charge / discharge actuator Therefore, the potential difference between the drive signal and the discharge destination potential is reduced, thereby reducing power consumption and heat generation. The drive signal generation circuit 72 and the potential preliminary adjustment circuits 26 and 27 are built in the interface unit 67.

  FIG. 7 shows specific circuit configurations of the potential preliminary adjustment circuit 26 and the drive signal generation circuit 72 of the present embodiment. In the present embodiment, only the charging source potential preliminary adjustment circuit 26 that preliminarily adjusts the charging source potentials to the plurality of drive signal generation circuits 72 is provided. Among these, each drive signal generation circuit 72 is equivalent to that described in Patent Document 2 described above, and is a push-pull connected charge transistor Tr1 and discharge transistor Tr2, and a drive waveform signal WCOM composed of digital signals. And a D / A converter 701 for converting the analog signal to the analog signal and a base driver circuit 702 for controlling the base voltages of the two transistors Tr1 and Tr2 in accordance with the analog-converted drive waveform signal WCOM. A charging source potential preliminary adjustment signal CCOM is supplied from the charging source potential preliminary adjustment circuit 26 to the collector of one of the two transistors Tr1 and Tr2, and the emitter is connected to the input side of the selection switch 201. The base is connected to one output of the base driver circuit 702. The emitter of the other PNP type discharge transistor Tr 2 is connected to the input side of the selection switch 201, the collector is grounded, and the base is connected to the other output of the base driver circuit 702. In this transistor pair, one charging transistor Tr1 supplies electric charge to the actuator 22 that is a capacitive load from the charging source potential preliminary adjustment signal CCOM through the selection switch 201 while accompanying a voltage waveform corresponding to the drive signal COM. That is, charging is performed, and the other discharging transistor Tr2 discharges the electric charge of the actuator 22 which is a capacitive load through the selection switch 201 with a voltage waveform corresponding to the driving signal COM.

  On the other hand, the charging source potential preliminary adjustment circuit 26 includes, for example, a charging source potential modulation circuit 24 that performs pulse modulation on the charging source potential preliminary adjustment waveform signal WCCOM generated in the same manner as the drive waveform signal WCOM described above, and the charging source potential. A charging source potential digital power amplifier that power-amplifies the charging source potential modulation signal CPWM pulse-modulated by the modulation circuit 24, so-called class D amplifier 28, and charging amplified by the charging source potential digital power amplifier 28 The charging source potential smoothing filter 30 that smoothes the original potential preliminary adjustment signal CCOM and outputs the smoothed output to the collector of the charging transistor Tr1 of each drive signal generation circuit 72 is provided.

  A general pulse width modulation (PWM) circuit is used as the charging source potential modulation circuit 24 that performs pulse modulation on the charging source potential preliminary adjustment waveform signal WCCOM. The charging source potential modulation circuit 24 of FIG. 7 includes a known triangular wave signal oscillator and a comparator that compares the triangular wave signal output from the triangular wave signal oscillator with the charging source potential preliminary adjustment waveform signal WCCOM. Composed. According to the charging source potential modulation circuit 24, for example, Hi when the charging source potential preliminary adjustment waveform signal WCCOM is greater than or equal to the triangular wave signal, and Lo when the charging source potential preliminary adjustment waveform signal WCCOM is less than the triangular wave signal. A modulation signal, a so-called PWM signal is output. In this embodiment, the pulse width modulation circuit is used as the pulse modulation circuit, but a pulse density modulation (PDM) circuit may be used instead.

  The charging source potential digital power amplifier, so-called class D amplifier 28, is composed of two MOSFETs TrP and TrN for substantially amplifying power, and is generally referred to as a charging source potential transistor pair 32; A gate driver circuit 34 for adjusting the gate-source signals GP and GN of the MOSFETs TrP and TrN based on the charging source potential modulation signal CPWM from the charging source potential modulation circuit 24; The source potential transistor pair 32 is a combination of a high-side MOSFET TrP and a low-side MOSFET TrN in a push-pull type. Among these, when the gate-source signal of the high-side MOSFET TrP is GP, the gate-source signal of the low-side MOSFET TrN is GN, and the output of the charging source potential transistor pair 32 is Va, these are the modulations for the charging source potential. FIG. 8 shows how it changes in accordance with the signal CPWM. This output characteristic is the same for the discharge destination potential transistor pair 33 that amplifies the power of a discharge destination potential modulation signal DPWM described later.

  For example, in this embodiment, when the charging source potential modulation signal CPWM is at the Hi level, the gate-source signal GP of the high-side MOSFET TrP is at the Hi level, and the gate-source signal GN of the low-side MOSFET TrN is at the Lo level. Therefore, the high-side MOSFET TrP is turned on and the low-side MOSFET TrN is turned off. As a result, the output Va of the charge source potential transistor pair 32 becomes, for example, the charge source potential Vdd. On the other hand, when the charging source potential modulation signal CPWM is at the Lo level, the gate-source signal GP of the high-side MOSFET TrP is at the Lo level, and the gate-source signal GN of the low-side MOSFET TrN is at the Hi level. The side-side MOSFET TrP is turned off and the low-side MOSFET TrN is turned on. As a result, the output Va of the charge source potential transistor pair 32 becomes zero.

  The output Va of the charge source potential transistor pair 32 of the charge source potential digital power amplification circuit 28 is supplied to the collector of the charge transistor Tr1 of each drive signal generation circuit 72 via the charge source potential smoothing filter 30. It is supplied as the adjustment signal CCOM. The charging source potential smoothing filter 30 is formed of, for example, an LC low-pass (low-pass) filter including a combination of one coil L and one capacitor C. The charge source potential smoothing filter 30 comprising a low-pass filter sufficiently attenuates the high-frequency component of the output Va of the charge source potential transistor pair 32 of the charge source potential digital power amplifier circuit 28, that is, the pulse modulation carrier signal component. Further, the charging source potential preliminary adjustment signal CCOM is designed not to attenuate.

  In the present embodiment, by appropriately setting the charging source potential preliminary adjustment waveform signal WCCOM, the potential of the charging source potential preliminary adjustment signal CCOM supplied to the collector of the charging transistor Tr1 of each drive signal generation circuit 72 is set. Adjustment is made so as to be slightly higher than the potential of the drive signal COM. There are two types of methods for adjusting the potential of the charging source potential preliminary adjustment signal CCOM. For example, the one shown in FIG. 9 a outputs the voltage value itself of the charging source potential preliminary adjustment signal CCOM from the four drive signal generation circuits 72. 9b is adjusted so as to be slightly higher than the maximum potential of the drive signal COM to be generated, and the one shown in FIG. 9b is obtained by making the phase of the charge source potential preliminary adjustment signal CCOM earlier than that of the drive signal COM. The potential preliminary adjustment signal CCOM is adjusted to be slightly higher than the maximum potential of the drive signal COM output from the four drive signal generation circuits 72.

  In this embodiment, the shaded area in FIGS. 9a and 9b corresponds to power consumption. In this embodiment, since the discharge destination potential is not preliminarily adjusted, the power consumption due to the potential difference between the drive signal COM and the discharge destination potential, that is, the ground potential does not change, but the charging transistor Tr1 of each drive signal generation circuit 72 does not change. Since the potential of the charge source potential preliminary adjustment signal CCOM supplied to the collector is adjusted to be slightly higher than the potential of the drive signal COM, power consumption due to the potential difference between the two is small.

  FIG. 10A is a reference example in which the charging source potential preliminary adjustment circuit 26 is not provided and the charging source potential Vdd is supplied as it is to the collector of the charging transistor Tr1 of the drive signal generation circuit 72. FIG. 10B shows the same as FIG. The power consumption is indicated by hatching. For ease of understanding, the same reference numerals as those in the embodiment are used. In this power consumption diagram, the potential difference between the charging source potential Vdd and the drive signal COM is larger than that of the present embodiment in which the charging source potential is preliminarily adjusted, and the power consumption is naturally large. When the power consumption increases, the amount of heat generation increases, so the size of the transistor used must be increased to improve heat resistance, or a heat sink must be provided to actively dissipate heat. When the drive signal generation circuit 72 is provided for each of the plurality of nozzle groups as in this example, the amount of heat generated in each drive signal generation circuit 72 is larger than that in the case where there is only one drive signal generation circuit 72. However, the number of heat sinks increases accordingly. That is, the mounting area on the circuit board becomes very large, and the obstacle in the layout is large.

  On the other hand, in the present embodiment, since power consumption can be reduced and the amount of heat generated can be reduced as compared with the conventional printing apparatus, such measures are not necessary. In addition, the charge source potential preliminary adjustment signal CCOM supplied to the collector of the charge transistor Tr1 of each drive signal generation circuit 72 is preliminarily amplified by the charge source potential digital power amplifier 28 including the charge source potential transistor pair 32 and spare. By adjusting, the potential of the charge source potential preliminary adjustment signal CCOM can be accurately adjusted.

  As described above, according to the printing apparatus of the present embodiment, the drive waveform signal generation circuit 70 generates the drive waveform signal WCOM that serves as a reference of the signal for controlling the drive state of the actuator 22, and the generated drive waveform signal WCOM. Are output by the push-pull-connected charging transistor Tr1 and discharging transistor Tr2 of the drive signal generation circuit 72 and output the drive signal COM, a plurality of drive signals provided corresponding to each of the plurality of nozzle groups A charge source potential preliminary adjustment waveform signal WCCOM for preliminarily adjusting the charge source potential to the generation circuit 72 is generated, and this charge source potential preliminary adjustment waveform signal WCCOM is pulse-modulated by the charge source potential modulation circuit 24, The pulse-modulated charging source potential modulation signal CPWM is connected to the charging source potential digital power amplifier 28 by push-pull connection. The charge source potential transistor pair 32 performs power amplification, and the power source amplified preliminary charge adjustment signal CCOM is smoothed by the charge source potential smoothing filter 30 so that the charge transistors Tr1 of the plurality of drive signal generation circuits 72 are charged. Since the output is made to the collector, the potential difference between the charge source potential preliminary adjustment signal CCOM and the drive signal COM for charging the charge / discharge actuator can be reduced, and the power consumption can be reduced.

Further, if the charging source potential preliminary adjustment waveform signal WCCOM for adjusting the potential of the charging source potential preliminary adjustment signal CCOM is generated by adjusting the voltage value of the charging source potential preliminary adjustment signal CCOM, the drive signal COM Accuracy can be improved and power consumption can be further reduced.
If the charge source potential preliminary adjustment waveform signal WCCOM that adjusts the potential of the charge source potential preliminary adjustment signal CCOM by adjusting the phase of the charge source potential preliminary adjustment signal CCOM is generated, the accuracy of the drive signal COM It is possible to improve and further reduce power consumption.

  Further, a plurality of drive waveform signals WCOM having different waveforms corresponding to the plurality of nozzle groups into which the nozzles are divided are generated, and the potential of the charging source potential preliminary adjustment signal CCOM is directed toward the corresponding nozzle group. If all the output drive signals are adjusted to be higher than the potential during the charging period, the gradation variation of the liquid dots caused by the difference in individual nozzles due to the difference in ink characteristics and actuator drive characteristics will be reduced. The power consumption can be reduced.

  Next, a second embodiment of the printing apparatus of the present invention will be described with reference to FIG. The schematic configuration of the printing apparatus according to the present embodiment, the control device, the generation method of the drive waveform signal and the drive signal, and the configuration of the actuator selection are the same as those of the first embodiment. In this embodiment, a discharge destination potential preliminary adjustment circuit 27 is provided instead of the charge source potential preliminary adjustment circuit 26 of the first embodiment. The discharge destination potential preliminary adjustment circuit 27 is connected to the collector of the discharge transistor Tr2 of the plurality of drive signal generation circuits 72 provided in each of the plurality of nozzle groups, and determines the potential to be discharged from the discharge transistor Tr2. This is a preliminary adjustment. The collector of the charging transistor Tr1 of each drive signal generating circuit 72 is connected to the charging source potential Vdd.

  The discharge destination potential preliminary adjustment circuit 27 includes, for example, a discharge destination potential modulation circuit 25 that performs pulse modulation on the discharge destination potential preliminary adjustment waveform signal WDCOM generated in the same manner as the drive waveform signal WCOM described above. A discharge destination potential digital power amplifier, a so-called class D amplifier 29, which amplifies the power of the discharge destination potential modulation signal DPWM pulse-modulated by the modulation circuit 25, and a discharge destination whose power is amplified by the discharge destination potential digital power amplifier 29. A discharge destination potential smoothing filter 31 that smoothes the potential preliminary adjustment signal DCOM and outputs it to the collector of the discharge transistor Tr2 of each drive signal generation circuit 72 is provided.

  The discharge destination potential modulation circuit 25 that performs pulse modulation of the discharge destination potential preliminary adjustment waveform signal WDCOM is similar to the charge source potential modulation circuit 24 of the first embodiment in that it is a general pulse width modulation (PWM) circuit. Was used. In addition, the discharge destination potential digital power amplifier, so-called class D amplifier 29, is similar to the charge source potential digital power amplifier 28 of the first embodiment from two MOSFETs TrP and TrN for substantially amplifying power. And a gate for adjusting the gate-source signals GP and GN of the MOSFETs TrP and TrN on the basis of the discharge destination potential modulation signal DPWM from the discharge destination potential modulation circuit 25. The driver circuit 34 is provided. Similarly to the charge source potential smoothing filter 30 of the first embodiment, the discharge destination potential smoothing filter 31 is also an LC low-pass (low-pass) filter comprising a combination of one coil L and one capacitor C, for example. Consists of.

  In the present embodiment, by appropriately setting the discharge destination potential preliminary adjustment waveform signal WDCOM, the potential of the discharge destination potential preliminary adjustment signal DCOM supplied to the collector of the discharge transistor Tr2 of each drive signal generation circuit 72 is set. Adjustment is made so that it is slightly lower than the potential of the drive signal COM. There are two methods for adjusting the potential of the discharge destination potential preliminary adjustment signal DCOM. For example, the one shown in FIG. 12 a outputs the voltage value of the discharge destination potential preliminary adjustment signal DCOM itself from the four drive signal generation circuits 72. 12b is adjusted so as to be slightly lower than the minimum potential of the drive signal COM to be generated, and the one shown in FIG. 12b is the discharge destination by making the phase of the discharge destination potential preliminary adjustment signal DCOM earlier than that of the drive signal COM. The potential preliminary adjustment signal DCOM is adjusted to be slightly lower than the minimum potential of the drive signal COM output from the four drive signal generation circuits 72.

  In the present embodiment, the shaded area in FIGS. 12a and 12b corresponds to power consumption. In this embodiment, since the charge source potential is not preliminarily adjusted, the power consumption due to the potential difference between the drive signal COM and the discharge source potential Vdd does not change, but is supplied to the collector of the discharge transistor Tr2 of each drive signal generation circuit 72. Since the potential of the discharge destination potential preliminary adjustment signal DCOM is adjusted to be slightly lower than the potential of the drive signal COM, power consumption due to the potential difference between the two is small. Therefore, in this embodiment, since power consumption can be reduced and the amount of heat generated can be reduced as compared with the conventional printing apparatus, no countermeasure is required. Also, the discharge destination potential preliminary adjustment signal DCOM supplied to the collector of the discharge transistor Tr2 of each drive signal generating circuit 72 is preliminarily amplified by the discharge destination potential digital power amplifier 29 including the discharge destination potential transistor pair 33. By adjusting, the potential of the discharge destination potential preliminary adjustment signal DCOM can be adjusted accurately.

  As described above, according to the printing apparatus of the present embodiment, the drive waveform signal generation circuit 70 generates the drive waveform signal WCOM that serves as a reference of the signal for controlling the drive state of the actuator 22, and the generated drive waveform signal WCOM. Are output by the push-pull-connected charging transistor Tr1 and discharging transistor Tr2 of the drive signal generation circuit 72 and output the drive signal COM, a plurality of drive signals provided corresponding to each of the plurality of nozzle groups A discharge destination potential preliminary adjustment waveform signal WDCOM for preliminarily adjusting the discharge destination potential from the generation circuit 72 is generated, and this discharge destination potential preliminary adjustment waveform signal WDCOM is pulse-modulated by the discharge destination potential modulation circuit 25, Push-pull connection of the pulse-modulated discharge destination potential modulation signal DPWM to the discharge destination potential digital power amplifier 29 The discharge destination potential transistor pair 33 is amplified in power, and the power destination amplified discharge destination potential preliminary adjustment signal DCOM is smoothed by the discharge destination potential smoothing filter 31 to be discharged by the discharge transistors Tr2 of the plurality of drive signal generation circuits 72. Therefore, the potential difference between the discharge destination potential preliminary adjustment signal DCOM and the drive signal COM discharged from the charge / discharge actuator 22 can be reduced, and the power consumption can be reduced.

Further, if the discharge destination potential preliminary adjustment waveform signal WDCOM that adjusts the potential of the discharge destination potential preliminary adjustment signal DCOM by adjusting the voltage value of the discharge destination potential preliminary adjustment signal DCOM is generated, Accuracy can be improved and power consumption can be further reduced.
If the discharge destination potential preliminary adjustment waveform signal WDCOM for adjusting the potential of the discharge destination potential preliminary adjustment signal DCOM is generated by adjusting the phase of the discharge destination potential preliminary adjustment signal DCOM, the accuracy of the drive signal COM It is possible to improve and further reduce power consumption.

  Also, a plurality of drive waveform signals WCOM having different waveforms corresponding to the plurality of nozzle groups into which the nozzles are divided are generated, and the potential of the discharge destination potential preliminary adjustment signal DCOM is directed toward the corresponding nozzle group. If the output potential is adjusted to be lower than the potential during all the drive signal discharge periods, the gradation variation of liquid dots caused by differences in ink characteristics and actuator drive characteristics will be reduced, and further consumption will occur. Electric power can be reduced.

  Next, a third embodiment of the printing apparatus of the present invention will be described with reference to FIG. The schematic configuration of the printing apparatus according to the present embodiment, the control device, the generation method of the drive waveform signal and the drive signal, and the configuration of the actuator selection are the same as those of the first embodiment. In the present embodiment, in addition to the charge source potential preliminary adjustment circuit 26 of the first embodiment, the discharge destination potential preliminary adjustment circuit 27 of the second embodiment is also provided. In addition, since those structures and functions are the same as those of the first embodiment and the second embodiment, respectively, the same reference numerals are given to the same structures, and the detailed description thereof is omitted.

  In the present embodiment, by appropriately setting the charging source potential preliminary adjustment waveform signal WCCOM, the potential of the charging source potential preliminary adjustment signal CCOM supplied to the collector of the charging transistor Tr1 of each drive signal generation circuit 72 is set. The discharge supplied to the collector of the discharge transistor Tr2 of each drive signal generation circuit 72 by adjusting the potential to be slightly higher than the potential of the drive signal COM and appropriately setting the discharge destination potential preliminary adjustment waveform signal WDCOM. The potential of the preliminary potential preliminary adjustment signal DCOM is adjusted to be slightly lower than the potential of the drive signal COM. Among these, there are two methods for adjusting the potential of the charging source potential preliminary adjustment signal CCOM. For example, the one shown in FIG. 14 a uses the voltage value of the charging source potential preliminary adjustment signal CCOM itself as four drive signal generation circuits 72. 14b is adjusted so as to be slightly higher than the maximum potential of the drive signal COM output from FIG. 14, and the one shown in FIG. 14b is obtained by setting the phase of the charge source potential preliminary adjustment signal CCOM earlier than that of the drive signal COM. The charge source potential preliminary adjustment signal CCOM is adjusted to be slightly higher than the maximum potential of the drive signals output from the four drive signal generation circuits 72. Further, there are two types of methods for adjusting the potential of the discharge destination potential preliminary adjustment signal DCOM. For example, the one shown in FIG. 14 a uses the four drive signal generation circuits 72 to obtain the voltage value of the discharge destination potential preliminary adjustment signal DCOM. 14B is adjusted so as to be slightly lower than the minimum potential of the output drive signal COM, and the one shown in FIG. 14B is discharged by making the phase of the discharge destination potential preliminary adjustment signal DCOM earlier than that of the drive signal COM. The prior potential preliminary adjustment signal DCOM is adjusted so that it is slightly lower than the minimum potential of the drive signals output from the four drive signal generation circuits 72.

  In this embodiment, the shaded area in FIGS. 14a and 14b corresponds to power consumption. In the present embodiment, the potential of the charge source potential preliminary adjustment signal CCOM supplied to the collector of the charging transistor Tr1 of each drive signal generation circuit 72 is adjusted to be slightly higher than the potential of the drive signal COM. The power consumption due to the potential difference between them is small, and at the same time, the potential of the discharge destination potential preliminary adjustment signal DCOM supplied to the collector of the discharge transistor Tr2 of each drive signal generation circuit 72 is adjusted to be slightly lower than the potential of the drive signal COM. Therefore, power consumption due to the potential difference between the two is small. Therefore, in this embodiment, since power consumption can be reduced and the amount of heat generated can be reduced as compared with the conventional printing apparatus, no countermeasure is required. In addition, the charge source potential preliminary adjustment signal CCOM supplied to the collector of the charge transistor Tr1 of each drive signal generation circuit 72 is preliminarily amplified by the charge source potential digital power amplifier 28 including the charge source potential transistor pair 32 and spare. By adjusting, the potential of the charge source potential preliminary adjustment signal CCOM can be accurately adjusted, and the discharge destination potential preliminary adjustment signal DCOM supplied to the collector of the discharge transistor Tr2 of each drive signal generation circuit 72 is discharged. The potential of the discharge destination potential preliminary adjustment signal DCOM can be accurately adjusted by performing power amplification and preliminary adjustment by the discharge destination potential digital power amplifier 29 including the destination potential transistor pair 33.

  As described above, according to the printing apparatus of the present embodiment, the drive waveform signal generation circuit 70 generates the drive waveform signal WCOM that serves as a reference of the signal for controlling the drive state of the actuator 22, and the generated drive waveform signal WCOM. Are output by the push-pull-connected charging transistor Tr1 and discharging transistor Tr2 of the drive signal generation circuit 72 and output the drive signal COM, a plurality of drive signals provided corresponding to each of the plurality of nozzle groups A charging source potential preliminary adjustment waveform signal WCCOM for preliminarily adjusting the charging source potential to the generating circuit 72 is generated, and this charging source potential preliminary adjustment waveform signal WCCOM is pulse-modulated by the charging source potential modulation means 24, The pulse-modulated charging source potential modulation signal CPWM is connected to the charging source potential digital power amplifier 28 by push-pull connection. The charge source potential transistor pair 32 amplifies the power, and the power source amplified preliminary adjustment signal CCOM is smoothed by the charge source potential smoothing filter 30 and applied to the collector of the charge transistor Tr1 of the drive signal generation circuit 72. A discharge destination potential preliminary adjustment waveform signal WDCOM for preliminarily adjusting discharge destination source potentials from the plurality of drive signal generation circuits 72 is generated, and this discharge destination potential preliminary adjustment waveform signal WDCOM is used for the discharge destination potential. The modulation circuit 25 performs pulse modulation, and the pulse-modulated discharge destination potential modulation signal DPWM is amplified by the push-pull connected discharge destination potential transistor pair 33 of the discharge destination potential digital power amplifier 29. The discharge destination potential preliminary adjustment signal DCOM is smoothed by the discharge destination potential smoothing filter 31 to drive the drive signal generation circuit 7. Output to the collector of the discharge transistor Tr2 of the battery, the potential difference between the charge source potential preliminary adjustment signal CCOM and the drive signal COM charging the charge / discharge actuator 22 can be reduced, and the discharge destination potential preliminary adjustment signal. The potential difference between the DCOM and the drive signal COM discharged from the charge / discharge actuator 22 can be reduced, and the power consumption can be reduced.

  Further, by adjusting the voltage value of the charging source potential preliminary adjustment signal CCOM, a charging source potential preliminary adjustment waveform signal WCCOM for adjusting the potential of the charging source potential preliminary adjustment signal CCOM is generated, and the discharge destination potential preliminary adjustment signal DCOM. By generating the discharge destination potential preliminary adjustment waveform signal WDCOM that adjusts the potential of the discharge destination potential preliminary adjustment signal DCOM by adjusting the voltage value of the drive signal COM, the accuracy of the drive signal COM can be improved and further power consumption can be reduced. Reduction is possible.

  Further, by adjusting the phase of the charging source potential preliminary adjustment signal CCOM, a charging source potential preliminary adjustment waveform signal WCCOM for adjusting the potential of the charging source potential preliminary adjustment signal CCOM is generated, and the discharge destination potential preliminary adjustment signal DCOM If the discharge destination potential preliminary adjustment waveform signal WDCOM for adjusting the potential of the discharge destination potential preliminary adjustment signal DCOM is generated by adjusting the phase, the accuracy of the drive signal COM can be improved and the power consumption can be further reduced. It becomes possible.

  Further, a plurality of drive waveform signals WCOM having different waveforms corresponding to the plurality of nozzle groups into which the nozzles are divided are generated, and the potential of the charging source potential preliminary adjustment signal CCOM is directed toward the corresponding nozzle group. While adjusting the potential of all the output drive signals higher than the potential during the charging period, the potential of the discharge destination potential preliminary adjustment signal DCOM is adjusted during the discharge period of all the drive signals output to the corresponding nozzle group. If the adjustment is made lower than the potential, it is possible to reduce the gradation variation of the liquid dots caused by the difference in individual nozzles due to the difference in ink characteristics and the difference in actuator driving characteristics, and to further reduce the power consumption.

  Next, a fourth embodiment of the printing apparatus of the present invention will be described with reference to FIG. The schematic configuration of the printing apparatus according to the present embodiment, the control device, the generation method of the drive waveform signal and the drive signal, and the configuration of the actuator selection are the same as those of the first embodiment. In the present embodiment, a charge source and discharge destination potential preliminary adjustment circuit 23 is provided in place of the charge source potential preliminary adjustment circuit 26 of the first embodiment. This charge source and discharge destination potential preconditioning circuit 23 is connected to the charge transistor Tr1 collector of the drive signal generation circuit 72 provided in each of the plurality of nozzle groups via the first rectifier D1, and this charge transistor The original potential for charging Tr1 is preliminarily adjusted, and is also connected to the collector of the discharge transistor Tr2 of each drive signal generating circuit 72 via the second rectifier D2, and the potential discharged from the discharge transistor Tr2 is This is a preliminary adjustment.

  For example, the charge source and discharge destination potential preliminary adjustment circuit 23 performs pulse modulation on the charge source and discharge destination potential preliminary adjustment waveform signal WCDCOM generated by the potential preliminary adjustment waveform signal generation circuit 71 in the same manner as the drive waveform signal WCOM described above. A charge source and discharge destination potential modulation circuit 35 that performs power amplification of the charge source and discharge destination potential modulation signal CDPWM pulse-modulated by the charge source and discharge destination potential modulation circuit 35. The digital power amplifier, so-called class D amplifier 36, and the charge source and discharge destination potential preliminary adjustment signal CDCOM amplified by the charge source and discharge destination potential digital power amplifier 36 are smoothed to charge each drive signal generation circuit 72. Smoothing fill for charge source and discharge destination potentials output to the collector of the transistor Tr1 and the collector of the discharge transistor Tr2 Configured with a 38.

  The charge source and discharge destination potential modulation circuit 35 that performs pulse modulation of the charge source and discharge destination potential preliminary adjustment waveform signal WCDCOM, as in the case of the charge source potential modulation circuit 24 of the first embodiment, A width modulation (PWM) circuit was used. In addition, the charging source and discharging destination potential digital power amplifier, so-called class D amplifier 36, is similar to the charging source potential digital power amplifier 29 of the first embodiment, and includes two MOSFETs TrP for substantially amplifying power. Based on the charge source and discharge destination potential modulation circuit 35 from the charge source and discharge destination potential modulation circuit 35, the gates of the MOSFETs TrP and TrN And a gate driver circuit 34 for adjusting the inter-source signals GP and GN. Similarly to the charge source potential smoothing filter 30 of the first embodiment, the charge source and discharge destination potential smoothing filter 38 is also composed of, for example, an LC low-pass (low frequency band) comprising a combination of one coil L and one capacitor C. Pass) filter.

  In the present embodiment, by appropriately setting the charging source and discharging destination potential preliminary adjustment waveform signal WCDCOM, the charging source supplied to the collector of the charging transistor Tr1 of each drive signal generation circuit 72 when charging the actuator. In addition, the potential of the discharge destination potential preliminary adjustment signal CDCOM is adjusted to be slightly higher than the maximum potential of the drive signal COM output from the four drive signal generation circuits 72, and each drive signal generation circuit 72 is discharged during discharge from the actuator. The potentials of the charge source and discharge destination preliminary adjustment signal CDCOM supplied to the collector of the discharge transistor Tr2 are adjusted to be slightly lower than the minimum potential of the drive signal COM output from the four drive signal generation circuits 72. . There are two kinds of methods for adjusting the potentials of the charge source and discharge destination potential preliminary adjustment signal CDCOM. For example, the one shown in FIG. 16a drives the voltage value itself of the charge source and discharge destination potential preliminary adjustment signal CDCOM by four driving methods. The drive signal COM output from the signal generation circuit 72 is adjusted to be slightly higher than the maximum potential or slightly lower than the minimum potential, and the one shown in FIG. By making the phase of the adjustment signal CDCOM earlier than that of the drive signal COM, the potential of the charge source and discharge destination potential preliminary adjustment signal CDCOM becomes slightly higher than the maximum potential of the drive signals output from the four drive signal generation circuits 72. Or adjusted to be slightly lower than the minimum potential.

  In the present embodiment, the shaded areas in FIGS. 16a and 16b correspond to power consumption. In the present embodiment, the potential of the charge source and discharge destination potential preliminary adjustment signal CDCOM supplied to the collector of the charging transistor Tr1 of each drive signal generation circuit 72 is adjusted to be slightly higher than the potential of the drive signal COM. Therefore, the power consumption due to the potential difference between them is small, and at the same time, the potential of the charge source and discharge destination potential preliminary adjustment signal CDCOM supplied to the collector of the discharge transistor Tr2 of each drive signal generation circuit 72 is slightly smaller than the potential of the drive signal COM. Since the adjustment is made so that it is only low, the power consumption due to the potential difference between the two is small. Therefore, in this embodiment, since power consumption can be reduced and the amount of heat generated can be reduced as compared with the conventional printing apparatus, no countermeasure is required. Further, the charge source and discharge destination potential preliminary adjustment signal CDCOM supplied to the collector of the charge transistor Tr1 and the collector of the discharge transistor Tr2 of each drive signal generation circuit 72 is charged by the charge source and discharge destination potential transistor pair 37. The potential of the charge source and discharge destination potential preliminary adjustment signal CDCOM can be accurately adjusted by performing power amplification and preliminary adjustment by the digital power amplifier 36 for the original and discharge destination potentials.

  As described above, according to the printing apparatus of the present embodiment, the drive waveform signal generation circuit 70 generates the drive waveform signal WCOM that serves as a reference of the signal for controlling the drive state of the actuator 22, and the generated drive waveform signal WCOM. Are output by the push-pull-connected charging transistor Tr1 and discharging transistor Tr2 of the drive signal generation circuit 72 and output the drive signal COM, a plurality of drive signals provided corresponding to each of the plurality of nozzle groups A charge source and discharge destination potential preliminary adjustment waveform signal WCDCOM for preliminarily adjusting the charge source potential and the discharge destination potential to the generation circuit 72 is generated, and the charge source and discharge destination potential preliminary adjustment waveform signal WCDCOM is generated as the charge source. The pulse modulation is performed by the modulation circuit 35 for the discharge destination potential and the modulation signal CD for the charge source and the discharge destination potential which are pulse-modulated. The power of the WM is amplified by the charge-source and discharge-destination potential transistor pair 37 of the push-pull connection of the charge-source and discharge-destination-potential digital power amplifier 36. Since the charge source and discharge destination potential smoothing filter 38 is smoothed and output to the collector of the charge transistor Tr1 and the collector of the discharge transistor Tr2 of the drive signal generation circuit 72, the charge source and discharge destination potential preliminary adjustment signal CDCOM. And the drive signal COM for charging / discharging the charge / discharge actuator 22 can be reduced, and the power consumption can be reduced.

Further, by adjusting the voltage value of the charge source and discharge destination potential preliminary adjustment signal CDCOM, a charge source and discharge destination potential preliminary adjustment waveform signal WCDCOM for adjusting the potential of the charge source and discharge destination potential preliminary adjustment signal CDCOM is generated. As a result, it is possible to improve the accuracy of the drive signal COM and further reduce power consumption.
In addition, by adjusting the phase of the charge source and discharge destination potential preliminary adjustment signal CDCOM, a charge source and discharge destination potential preliminary adjustment waveform signal WCDCOM for adjusting the potential of the charge source and discharge destination potential preliminary adjustment signal CDCOM is generated. Then, the accuracy of the drive signal COM can be improved and the power consumption can be further reduced.

  In the above-described embodiment, only the example in which the liquid ejecting apparatus and the printing apparatus of the present invention are applied to a so-called line head type printing apparatus has been described in detail. The present invention can be applied to any type of printing apparatus including the apparatus. Moreover, each part which comprises the liquid ejecting apparatus or printing apparatus of this invention may be replaced with the thing of the arbitrary structures which can exhibit the same function, and the other arbitrary structures may be added.

  Moreover, it does not specifically limit as a liquid ejected from the liquid ejecting apparatus of this invention, For example, it can be set as the liquid (including dispersion liquids, such as a suspension and an emulsion) containing the following various materials. That is, an ink containing a filter material for a color filter, a light emitting material for forming an EL light emitting layer in an organic EL (Electro Luminescence) device, a fluorescent material for forming a phosphor on an electrode in an electron emitting device, PDP (Plasma Fluorescent material for forming phosphors in display panel devices, migrating material for forming electrophores in electrophoretic display devices, bank materials for forming banks on the surface of substrates, various coating materials, and electrodes Liquid electrode material for forming a spacer, a particle material for forming a minute cell gap between two substrates, a liquid metal material for forming a metal wiring, a lens material for forming a microlens, a resist Materials, light diffusing materials for forming light diffusers, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram illustrating a first embodiment of a line head type printing apparatus to which a liquid ejecting apparatus of the present invention is applied, where (a) is a plan view and (b) is a front view. It is a block block diagram of the control apparatus of the printing apparatus of FIG. It is explanatory drawing of drive waveform signal generation. It is explanatory drawing of the drive waveform signal or drive signal connected in time series. It is a block block diagram of a drive signal generation system. It is a block diagram of the selection part which connects a drive signal to an actuator. FIG. 6 is a block diagram showing details of a drive signal generation circuit and a potential preliminary adjustment circuit of the drive signal generation system of FIG. 5. It is explanatory drawing of an effect | action of the digital power amplifier of the electric potential preliminary adjustment circuit of FIG. It is explanatory drawing of an effect | action of the drive signal generation system of FIG. It is a block diagram of a conventional drive signal generation system and an explanatory diagram of its operation. It is a block block diagram of the drive signal generation system which shows 2nd Embodiment of the line head type printing apparatus to which the liquid ejecting apparatus of this invention is applied. It is explanatory drawing of an effect | action of the drive signal generation system of FIG. It is a block block diagram of the drive signal generation system which shows 3rd Embodiment of the line head type printing apparatus to which the liquid ejecting apparatus of this invention is applied. It is explanatory drawing of an effect | action of the drive signal generation system of FIG. It is a block block diagram of the drive signal generation system which shows 4th Embodiment of the line head type printing apparatus to which the liquid ejecting apparatus of this invention is applied. It is explanatory drawing of an effect | action of the drive signal generation system of FIG.

Explanation of symbols

  1 is a print medium, 2 is a first liquid ejecting head, 3 is a second liquid ejecting head, 4 is a first transport unit, 5 is a second transport unit, 6 is a first transport belt, 7 is a second transport belt, and 8R. , 8L are driving rollers, 9R and 9L are first driven rollers, 10R and 10L are second driven rollers, 11R and 11L are electric motors, 22 are actuators, 23 are charging source and discharging destination potential preliminary adjustment circuits, and 24 is charging. Original potential modulation circuit, 25 is a discharge destination potential modulation circuit, 26 is a charge source potential preliminary adjustment circuit, 27 is a discharge destination potential preliminary adjustment circuit, 28 is a charge source potential digital power amplifier, and 29 is a discharge destination potential digital power amplifier. , 30 is a charging source potential smoothing filter, 31 is a discharging destination potential smoothing filter, 32 is a charging source potential transistor pair, 33 is a discharging destination potential transistor pair, 34 is a gate driver circuit, and 35 is a charging source. And a discharge destination potential modulation circuit, 36 is a charge source and discharge destination potential digital power amplifier, 37 is a charge source and discharge destination potential transistor pair, 38 is a charge source and discharge destination potential smoothing filter, 62 is a control unit, 70 is a drive waveform signal generation circuit, 71 is a potential preliminary adjustment waveform signal generation circuit, 72 is a drive signal generation circuit, Tr1 is a charge transistor, and Tr2 is a discharge transistor.

Claims (16)

  A liquid ejecting apparatus comprising: a plurality of nozzles provided in a liquid ejecting head; a charge / discharge actuator provided corresponding to the nozzle; and a driving unit that applies a driving signal to the actuator. Drive waveform signal generating means for generating a drive waveform signal serving as a reference of a signal for controlling the driving of the plurality of nozzles, a charge transistor and a discharge transistor provided in each of the plurality of nozzle groups into which the nozzles are divided and push-pull connected A plurality of drive signal generation means for amplifying the drive waveform signal generated by the drive waveform signal generation means and outputting a drive signal toward the corresponding nozzle group, and charging sources for the plurality of drive signal generation means Charging source potential preliminary adjustment waveform signal generating means for generating a charging source potential preliminary adjustment waveform signal for preliminary adjustment of the potential; The plurality of drives based on the charging source potential preliminary adjustment waveform signal that is disposed between the charging source to the dynamic signal generation unit and the driving signal generation unit and is generated by the charging source potential preliminary adjustment waveform signal generation unit. Charging source potential preliminary adjusting means for preliminarily adjusting the charging source potential to the signal generating means, wherein the charging source potential preliminary adjusting means is the charging source potential preliminary adjustment generated by the charging source potential preliminary adjusting waveform signal generating means. Charge source potential modulation means for pulse-modulating the waveform signal, and charge source for power amplification of the charge source potential modulation signal pulse-modulated by the charge source potential modulation means by a push-pull connected charge source potential transistor pair A potential digital power amplifier and a charge source potential preliminary adjustment signal amplified by the charge source potential digital power amplifier are supplied to a charge transistor of the drive signal generating means. A liquid ejecting apparatus characterized by comprising a smoothing filter for charging source potential output selector.   The charging source potential preliminary adjustment waveform signal generating means generates a charging source potential preliminary adjustment waveform signal for adjusting the potential of the charging source potential preliminary adjustment signal by adjusting a voltage value of the charging source potential preliminary adjustment signal. The liquid ejecting apparatus according to claim 1.   The charging source potential preliminary adjustment waveform signal generating means generates a charging source potential preliminary adjustment waveform signal for adjusting the potential of the charging source potential preliminary adjustment signal by adjusting the phase of the charging source potential preliminary adjustment signal. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is a liquid ejecting apparatus.   The drive waveform signal generating means generates a plurality of drive waveform signals having different waveforms corresponding to each of a plurality of nozzle groups into which the nozzles are divided, and the potential of the charge source potential preliminary adjustment signal corresponds to the corresponding one. 4. The liquid ejecting apparatus according to claim 1, wherein all of the drive signals output toward the nozzle group are set higher than the potential during the charging period. 5.   A liquid ejecting apparatus comprising: a plurality of nozzles provided in a liquid ejecting head; a charge / discharge actuator provided corresponding to the nozzle; and a driving unit that applies a driving signal to the actuator. Drive waveform signal generating means for generating a drive waveform signal serving as a reference of a signal for controlling the driving of the plurality of nozzles, a charge transistor and a discharge transistor provided in each of the plurality of nozzle groups into which the nozzles are divided and push-pull connected A plurality of drive signal generating means for amplifying the drive waveform signal generated by the drive waveform signal generating means and outputting a drive signal toward the corresponding nozzle group, and potentials of discharge destinations of the plurality of drive signal generating means Discharge destination potential preliminary adjustment waveform signal generating means for generating a discharge destination potential preliminary adjustment waveform signal for preliminary adjustment, and the plurality of drives The plurality of drive signals are arranged between the discharge destination from the signal generating means and the drive signal generating means and based on the discharge destination potential preliminary adjustment waveform signal generated by the discharge destination potential preliminary adjustment waveform signal generation means. Discharge destination potential preliminary adjustment means for preliminarily adjusting the discharge destination potential from the generating means, wherein the discharge destination potential preliminary adjustment means is a discharge destination potential preliminary adjustment waveform generated by the discharge destination potential preliminary adjustment waveform signal generation means. Discharge destination potential modulation means for pulse-modulating a signal, and discharge destination potential for power amplification of a discharge destination potential modulation signal pulse-modulated by the discharge destination potential modulation means by a push-pull connected discharge destination potential transistor pair Digital power amplifier, and discharge destination potential preliminary adjustment signal amplified by the discharge destination potential digital power amplifier as a discharge transistor of the drive signal generating means A liquid ejecting apparatus characterized by comprising a discharge destination potential smoothing filter for outputting to the collector.   The discharge destination potential preliminary adjustment waveform signal generating means generates a discharge destination potential preliminary adjustment waveform signal for adjusting a potential of the discharge destination potential preliminary adjustment signal by adjusting a voltage value of the discharge destination potential preliminary adjustment signal. The liquid ejecting apparatus according to claim 5.   The discharge destination potential preliminary adjustment waveform signal generation means generates a discharge destination potential preliminary adjustment waveform signal that adjusts the potential of the discharge destination potential preliminary adjustment signal by adjusting the phase of the discharge destination potential preliminary adjustment signal. The liquid ejecting apparatus according to claim 5.   The drive waveform signal generating means generates a plurality of drive waveform signals having different waveforms corresponding to the plurality of nozzle groups into which the nozzles are divided, and the potential of the discharge destination potential preliminary adjustment signal corresponds to the corresponding one. 8. The liquid ejecting apparatus according to claim 5, wherein all of the drive signals output toward the nozzle group are set lower than the potential during the discharge period.   A liquid ejecting apparatus comprising: a plurality of nozzles provided in a liquid ejecting head; a charge / discharge actuator provided corresponding to the nozzle; and a driving unit that applies a driving signal to the actuator. Drive waveform signal generating means for generating a drive waveform signal serving as a reference of a signal for controlling the driving of the plurality of nozzles, a charge transistor and a discharge transistor provided in each of the plurality of nozzle groups into which the nozzles are divided and push-pull connected A plurality of drive signal generation means for amplifying the drive waveform signal generated by the drive waveform signal generation means and outputting a drive signal toward the corresponding nozzle group, and charging sources for the plurality of drive signal generation means Charging source potential preliminary adjustment waveform signal generating means for generating a charging source potential preliminary adjustment waveform signal for preliminary adjustment of the potential; The plurality of drives based on the charging source potential preliminary adjustment waveform signal that is disposed between the charging source to the dynamic signal generation unit and the driving signal generation unit and is generated by the charging source potential preliminary adjustment waveform signal generation unit. Charge source potential preliminary adjustment means for preliminarily adjusting the charge source potential to the signal generation means, and discharge destination for generating a discharge destination potential preliminary adjustment waveform signal for preliminarily adjusting the discharge destination potentials of the plurality of drive signal generation means Discharge destination generated between the potential pre-adjustment waveform signal generation means, the discharge destinations from the plurality of drive signal generation means and the drive signal generation means, and generated by the discharge destination potential pre-adjustment waveform signal generation means Discharge destination potential preliminary adjustment means for preliminarily adjusting discharge destination potentials from the plurality of drive signal generation means based on a potential preliminary adjustment waveform signal, and the charge source potential preliminary adjustment means includes the charge source potential Charge source potential modulation means for pulse-modulating the charge source potential preliminary adjustment waveform signal generated by the preparation adjustment waveform signal generation means, and pulse by the charge source potential modulation means by a push-pull connected charge source potential transistor pair A charge source potential digital power amplifier for power amplification of the modulated charge source potential modulation signal, and a charge source potential preliminary adjustment signal amplified by the charge source potential digital power amplifier for charging the drive signal generating means A charge source potential smoothing filter that outputs to the collector of the transistor, and the discharge destination potential preliminary adjustment means performs pulse modulation on the discharge destination potential preliminary adjustment waveform signal generated by the discharge destination potential preliminary adjustment waveform signal generation means. The discharge destination potential modulation means and the discharge destination potential modulation pair are connected to the discharge destination potential modulation means by a push-pull connection. A discharge destination potential digital power amplifier that amplifies the modulated discharge destination potential modulation signal, and a discharge destination potential preliminary adjustment signal amplified by the discharge destination potential digital power amplifier for discharge of the drive signal generating means A liquid ejecting apparatus comprising: a smoothing filter for a discharge destination potential output to a collector of a transistor.   The charging source potential preliminary adjustment waveform signal generating means generates a charging source potential preliminary adjustment waveform signal for adjusting the potential of the charging source potential preliminary adjustment signal by adjusting a voltage value of the charging source potential preliminary adjustment signal, The discharge destination potential preliminary adjustment waveform signal generating means generates a discharge destination potential preliminary adjustment waveform signal for adjusting a potential of the discharge destination potential preliminary adjustment signal by adjusting a voltage value of the discharge destination potential preliminary adjustment signal. The liquid ejecting apparatus according to claim 9.   The charging source potential preliminary adjustment waveform signal generating means generates a charging source potential preliminary adjustment waveform signal for adjusting the potential of the charging source potential preliminary adjustment signal by adjusting the phase of the charging source potential preliminary adjustment signal, The discharge destination potential preliminary adjustment waveform signal generation means generates a discharge destination potential preliminary adjustment waveform signal that adjusts the potential of the discharge destination potential preliminary adjustment signal by adjusting the phase of the discharge destination potential preliminary adjustment signal. The liquid ejecting apparatus according to claim 9.   The drive waveform signal generating means generates a plurality of drive waveform signals having different waveforms corresponding to each of a plurality of nozzle groups into which the nozzles are divided, and the potential of the charge source potential preliminary adjustment signal corresponds to the corresponding one. All the drive signals output to the nozzle group are set higher than the potential during the charging period, and the potential of the discharge destination potential preliminary adjustment signal is set to all the drive signals output to the corresponding nozzle group. The liquid ejecting apparatus according to claim 9, wherein the liquid ejecting apparatus is set lower than a potential during a discharge period.   A liquid ejecting apparatus comprising: a plurality of nozzles provided in a liquid ejecting head; a charge / discharge actuator provided corresponding to the nozzle; and a driving unit that applies a driving signal to the actuator. Drive waveform signal generating means for generating a drive waveform signal serving as a reference of a signal for controlling the driving of the plurality of nozzles, a charge transistor and a discharge transistor provided in each of the plurality of nozzle groups into which the nozzles are divided and push-pull connected A plurality of drive signal generation means for amplifying the drive waveform signal generated by the drive waveform signal generation means and outputting a drive signal toward the corresponding nozzle group, and charging sources for the plurality of drive signal generation means Generates pre-adjustment waveform signals for the charge source and discharge destination potential for pre-adjusting the potential and the potential of the discharge destination from the drive signal generating means The charging source and destination potential preliminary adjustment waveform signal generating means, the charging source to the plurality of driving signal generating means and the discharging destination from the driving signal generating means, and the driving signal generating means, and Based on the charge source and discharge destination potential preliminary adjustment waveform signals generated by the charge source and discharge destination potential preliminary adjustment waveform signal generation means, the charge source potentials to the plurality of drive signal generation means and the drive signal generation means from the drive signal generation means Charging source and discharge destination potential preliminary adjustment means for preliminarily adjusting the discharge destination potential, wherein the charging source and discharge destination potential preliminary adjustment means are the charges generated by the charging source and discharge destination potential preliminary adjustment waveform signal generation means. The charge source and the discharge destination potential modulating means for pulse-modulating the source and discharge destination potential preconditioning waveform signals, and the charge source and the discharge destination potential transistor pair connected in a push-pull manner. A charge source and discharge destination potential digital power amplifier that amplifies the power of the charge source and discharge destination potential modulation signals pulse-modulated by the discharge destination potential modulation means, and power by the charge source and discharge destination potential digital power amplifier. A charge source and discharge destination potential smoothing filter for outputting the amplified charge source and discharge destination potential preliminary adjustment signals to the collector of the charge transistor and the collector of the discharge transistor of the drive signal generating means; Liquid ejecting device.   The charging source and discharge destination potential preliminary adjustment waveform signal generating means adjusts the voltage value of the charging source and discharge destination potential preliminary adjustment signal to adjust the potential of the charging source and discharge destination potential preliminary adjustment signal. And a discharge destination potential pre-adjustment waveform signal.   The charging source and discharge destination potential preliminary adjustment waveform signal generating means adjusts the phase of the charging source and discharge destination potential preliminary adjustment signal to adjust the potential of the charging source and discharge destination potential preliminary adjustment signal, and The liquid ejecting apparatus according to claim 13, wherein a discharge destination potential preliminary adjustment waveform signal is generated.   A printing apparatus comprising the liquid ejecting apparatus according to claim 1.

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