JP2009143142A - Driving device of droplet discharge head and driving program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving device of a droplet discharge head which can avoid an adverse effect of meniscus vibration and reduce power consumption by a simple circuit constitution and a driving program. <P>SOLUTION: When current discharge is followed by subsequent discharge, switches of a discharge pulse portion and a nondischarge pulse portion in a printing period which show a waveform selective condition continue to be turned on and a driving waveform is applied even in the discharge pulse portion and the nondischarge pulse portion. When current discharge is followed by nondischarge, the switch of the discharge pulse portion in a printing period which shows the waveform selective condition is turned on and the switch of the nondischarge pulse portion is turned off. At that time, a driving waveform is applied in the discharge pulse portion and not applied in the nondischarge pulse portion. When nondischarge is currently in progress, the switches of the discharge pulse portion and the nondischarge pulse portion during a printing period which show the waveform selective condition continue to be turned off, and no driving waveform is applied even in the discharge pulse portion and the nondischarge pulse portion. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a driving device and a driving program for a droplet discharge head.

  The inkjet head applies a pulse-like drive waveform to a piezoelectric actuator (Piezo Actuator: hereinafter referred to as an actuator), so that a part of the wall expands and contracts, and a droplet (for example, When the ink) is pushed out, droplets are landed on the recording medium and recording is performed.

  In particular, when performing high-speed printing, since the next ejection pulse is applied before the oscillation of the meniscus (interface) is attenuated, the ejection becomes unstable (for example, ejection failure such as erroneous ejection or non-ejection). May be. Therefore, in order to prevent ejection failure (to stabilize ejection), meniscus vibration (hydrodynamic vibration of the droplet itself) due to the ejection pulse does not affect the next ejection, and non-ejection pulses are applied to the actuator. It is known to be applied to. Note that the non-ejection pulse is also referred to as a reverberation suppression pulse and is a driving pulse that does not lead to ejection.

By the way, in the ink liquid ejecting apparatus, the canceling operation for canceling the pressure wave vibration of the ink is performed with or without a print command at the print timing before, after, or after the print timing corresponding to a predetermined cycle. Or the structure which switches non-execution is proposed (refer patent document 1 and patent document 2).
JP 11-348275 A JP 2004-114704 A

  An object of the present invention is to provide a driving device and a driving program for a droplet discharge head that can avoid the adverse effects of meniscus vibration and reduce power consumption with a simple circuit configuration.

  According to the first aspect of the present invention, a pressure chamber to which droplets are supplied, a piezoelectric element that changes the pressure in the pressure chamber based on a predetermined drive waveform, and a predetermined pressure in the pressure chamber communicated with the pressure chamber space. A droplet discharge section that discharges the droplets when the above pressure change occurs, a droplet discharge head having a plurality of droplet ejectors arranged thereon, and a drive for discharging and printing the droplets A drive waveform generating means for generating a discharge pulse that is a waveform, and a non-discharge pulse that is a drive waveform for performing at least reverberation suppression without discharging the droplet, and one of the discharge pulse and the non-discharge pulse, Or, based on the combination, a print execution control means for executing printing, and when executing the printing by the print execution control means, the discharge pulse is output at the time of the next printing after the predetermined printing, based on the predetermined printing time Shina Case, and a drive waveform selecting means for selecting a combination of said drive waveform to not adding the non-discharge pulse at the predetermined printing.

  According to a second aspect of the present invention, in the first aspect of the invention, when the drive waveform selecting means outputs the ejection pulse at the time of the next printing at the predetermined printing, the non-printing at the predetermined printing time. The combination of the drive waveforms is selected so that the ejection pulse is added.

  According to a third aspect of the present invention, in the first aspect of the invention, in the case where the drive waveform selecting means outputs the ejection pulse at the time of the predetermined printing and at the time of the next printing, the ejection at the time of the predetermined printing. The combination of the drive waveforms is selected so that the non-ejection pulse is added in addition to the pulse.

  According to a fourth aspect of the present invention, a pressure chamber to which droplets are supplied, a piezoelectric element that changes the pressure in the pressure chamber based on a predetermined driving waveform, and a predetermined pressure in the pressure chamber that communicates with the pressure chamber space. In a driving program for a droplet discharge head in which a plurality of droplet ejectors including a droplet discharge unit that discharges the droplet when the above pressure change occurs is arranged, the droplets are discharged and printed. A discharge waveform that is a drive waveform for generating a non-discharge pulse that is a drive waveform for performing at least reverberation suppression without discharging the droplet, and one or a combination of the discharge pulse and the non-discharge pulse If the discharge pulse is not output at the time of the next printing at the time of the predetermined printing when the printing is performed based on the predetermined printing time, vomit Selecting a combination of said drive waveform to not adding pulse, it is characterized in that it run on the computer.

  According to a fifth aspect of the present invention, there is provided a pressure chamber to which droplets are supplied, a piezoelectric element that changes the pressure in the pressure chamber based on a predetermined drive waveform, and a predetermined pressure in the pressure chamber that communicates with the pressure chamber space. A droplet ejection head having a plurality of droplet ejectors each having a droplet ejection section that ejects the droplet when the above pressure change occurs; and a predetermined pattern for the droplet ejection head Print execution means for generating a drive waveform and executing printing; drive waveform pattern setting means for setting a predetermined number of drive waveform patterns based on sorting requirements including the droplet volume of the droplet; A mode distribution means for allocating the drive waveform pattern to a plurality of print droplet modes and one non-print droplet mode, and the drive waveform pattern setting means based on a print condition including an image designated at the time of printing. Set in A distribution ratio is changed based on a mode specified at the time of printing when the drive waveform pattern is selected by the drive waveform pattern and the drive waveform pattern is distributed by the mode distribution unit. And a distribution ratio changing means.

  According to a sixth aspect of the present invention, a pressure chamber to which droplets are supplied, a piezoelectric element that changes the pressure in the pressure chamber based on a predetermined driving waveform, and a predetermined pressure in the pressure chamber that communicates with the pressure chamber space. A droplet discharge head that includes a droplet discharge unit that discharges the droplet when the above pressure change occurs. When a printing waveform is generated and printing is performed, a predetermined number of driving waveform patterns are set based on the sorting requirements including the droplet volume of the droplet, and a plurality of printing droplet modes are set. In addition, when allocating the drive waveform pattern to one non-print droplet mode, the distribution ratio is changed based on the print condition including the image specified at the time of printing, and the image specified at the time of printing is changed. Based on the printing conditions including To generate the selected driving waveform from the driving waveform pattern number is set with, it is characterized in that it run on the computer.

  As described above, according to the first aspect, it is possible to avoid the adverse effects of meniscus vibration and reduce power consumption with a simple circuit configuration.

  According to claim 2, it is possible to reduce power by applying the non-ejection pulse to the minimum necessary.

  Furthermore, according to the third aspect, it is possible to reduce power by applying fewer non-ejection pulses.

  According to the fourth aspect of the present invention, it is possible to avoid the adverse effects of meniscus vibration and reduce power consumption with a simple circuit configuration.

  Furthermore, according to the fifth aspect, it is possible to obtain the effect that the most effective correction for improving the image quality can be performed.

  According to the sixth aspect of the present invention, it is possible to select an optimum drive waveform pattern with a limited number of drive waveform patterns.

(First embodiment)
As shown in FIG. 1, this configuration mainly includes a client PC 110 and an inkjet image forming apparatus 120, and the image forming apparatus 120 includes an interface unit 130, an information processing unit 140, and an image forming unit 160.

  The information processing unit 140 includes a print control unit 142, a CPU (Central Processing Unit) 144, a ROM (Read Only Memory) 146, a RAM (Random Access Memory) 148, and an HDD (Hard Disk Drive) 150. .

  Further, the print control unit 142 includes a head controller 170, a drive waveform generation circuit 180, and a SWIC (switching IC) 190 including a waveform selection circuit 192.

  Data input to the image forming apparatus 120 is input to the information processing unit 140 via the interface unit 130, and data processing is performed. Specifically, the CPU 144 performs data processing on the input data using the RAM 148 or the HDD 150 as a work area and a storage area according to a processing program stored in the ROM 146 or the HDD 150. Then, according to a print instruction from the client PC 110, print data, a print instruction, and the like are transmitted from the information processing unit 140 of the image forming apparatus 120 to the image forming unit 160.

  The image forming unit 160 includes a droplet discharge head 211 having a plurality of droplet ejectors 224 (see FIG. 3). The image forming unit 160 discharges droplets (records or prints print data) on a recording medium based on print data, a print instruction, a processing program, and the like transmitted from the information processing unit 140.

  In this printing system, the client PC 110 transfers a print command, print mode information, print data, and the like to the image forming apparatus 120. The image forming apparatus 120 performs printing based on the print mode and print data transferred from the client PC 110. Further, the droplet discharge head 211 is composed of YMCK four-color droplet discharge heads.

  As shown in FIGS. 2A and 2B, in the droplet discharge head 211 provided with the droplet discharge head bar 213, the droplet discharge head units 214 are arranged in series in the longitudinal direction in a flat bar shape, As a result, the ejector bases 216 and 218 are two-dimensionally arranged.

  As shown in FIG. 3, the droplet ejector 224 is provided corresponding to each nozzle 302 having a nozzle plate 303 formed with a plurality of droplet discharge sections (hereinafter referred to as nozzles) 302 and filled with droplets. Pressure chamber 304, a droplet supply path 305 for supplying droplets from a droplet tank (not shown) to the pressure chamber 304, and a piezoelectric element (hereinafter referred to as an actuator) 307 provided corresponding to the pressure chamber 304. Yes.

  As shown in FIG. 4, the first drive device 400 includes a drive waveform generation circuit 433, a switching unit 434, and a head controller 170.

  The drive waveform generation circuit 433 normally generates a drive waveform that is a drive signal, but generates a plurality of types of waveforms by cutting out one waveform.

  Further, a SWIC (Switching Integrated Circuit) 434 which is a driver IC switches a driving waveform supplied to an actuator 307 (see FIG. 3) provided in each droplet ejector 224 (see FIG. 3).

  Furthermore, the head controller 170 includes a storage unit (not shown) in which data necessary for driving the drive waveform generation circuit 433 is stored in advance, and controls the drive of each unit and the transmission and reception of various signals.

  In the droplet discharge head 211 (see FIG. 2), waveform data corresponding to droplets (large droplets, medium droplets, small droplets) having different droplet diameters is generated by the drive waveform generation circuit 433 as a drive waveform. In addition, it is possible to print droplets having different droplet diameters (gradation printing). The waveform data is stored in the storage unit of the head controller 170 and is given to the drive waveform generation circuit 433 by the head controller 170.

  The storage unit of the head controller 170 also stores waveform data without droplet discharge. This waveform data is used to discharge droplets in the pressure chamber 304 (see FIG. 3) in order to prevent the droplets from coming into contact with air near the nozzle 302 (see FIG. 3) and thickening to change the discharge characteristics. This is data for generating a drive waveform for stirring at a pressure that does not occur. This drive waveform without droplet ejection is also called a non-ejection pulse or a reverberation suppression pulse.

  The drive waveform generation circuit 433 is connected to an actuator 307 (see FIG. 3) provided in each droplet ejector 224 (see FIG. 3) by a signal line. In order to supply the drive waveform generated and cut out by the drive waveform generation circuit 433 to the actuator 307 (see FIG. 3), a switch 437 is provided between each signal line and the actuator 307 (see FIG. 3). It has been. When the switch 437 is turned on or off, the drive waveform generated by the drive waveform generation circuit 433 is supplied to each actuator 307 (see FIG. 3). The switching of each switch 437 is turned on or off by the waveform selection circuit 436 of the SWIC 434 based on a command signal from the head controller 170, thereby controlling the driving of each actuator 307 (see FIG. 3).

  The operation of the first embodiment of the present invention will be described below.

  As shown in the first flowchart of FIG. 6A, in step 610, it is determined whether an instruction has been received. Specifically, it is determined whether or not a command (including print data, a print instruction, a command, setting data, and the like) from the client PC 110 (see FIG. 1) has been received. If the command from the client PC 110 (see FIG. 1) is received, the process proceeds to step 620. If the command from the client PC 110 (see FIG. 1) is not received, the process waits until the command is received and waits for the command.

  In step 620, a charging process is performed. Specifically, charging is performed up to the bias potential.

  In step 630, a drive waveform is generated and a process for selecting the generated drive waveform is performed. Specifically, the processing (second flowchart) in FIG. 6B, which is an example of control of the drive waveform generation circuit 433 (see FIG. 4) and the SWIC 434 (see FIG. 4) within one printing cycle focusing on one nozzle. ) For all droplet ejectors 224 (see FIG. 3).

  In step 640, it is determined whether or not printing of the designated number of times has been completed. If completed, the process proceeds to step 650. If not completed, the process returns to step 630 and is repeated until the process is completed.

  In step 650, a discharge process is performed. In detail, it is similar to step 620, and discharge processing from a bias potential is performed.

  In step 660, it is determined whether or not all printing has been completed. Specifically, whether or not all printing of the transmitted print data is completed based on a command including print data, a print instruction, a command, and setting data transmitted from the client PC 110 (see FIG. 1). Determine whether or not. If printing of all the transmitted print data has been completed, the process ends. If not, the process returns to step 610 to wait for a command from the client PC 110 (see FIG. 1).

  As shown in the second flowchart of FIG. 6B, in step 670, an ejection pulse (drive waveform) selection process is performed. Specifically, the drive waveform generation circuit 433 (see FIG. 4) within one print cycle is controlled, drive data is generated so as to select an ejection pulse from the print data, and the SWIC 434 (see FIG. 4) is controlled (one print). (Control of the waveform selection circuit 436 within the period).

  In step 680, it is determined whether there is next print data. Specifically, the specified printing time is the current printing time and the standard printing time (standard printing time), and it is determined whether or not there is print data within the next printing cycle at the time of the standard printing. To do. If there is print data within the next one print cycle at the time of reference printing, the process proceeds to step 690, and if not, the generation of the drive waveform and the selection process of the generated drive waveform are terminated.

  In step 690, a non-ejection pulse (reverberation suppression pulse) selection process is performed. More specifically, if the specified print time is the current print time (current print time) and the standard print time, and if there is print data within the next print cycle of the standard print time, the non-ejection pulse is set. Select and output. By applying a non-ejection pulse to the actuator 307 (see FIG. 3), meniscus vibration due to the ejection pulse does not affect the next ejection, thereby preventing the next ejection failure (stabilizing the next ejection). .

  As shown in FIG. 8, FIG. 8 is an example of a driving waveform applied to the actuator 307 (see FIG. 3) in FIG. 4, and the first half of the printing cycle shows the ejection pulse portion in the printing cycle. In the second half of the printing cycle, the non-ejection pulse portion is shown. When a predetermined print time is used as the current print time (current print time) as a reference (during standard print time), and a discharge pulse is output to discharge and discharge droplets at the next print time after the predetermined print time. For this, a combination of drive waveforms is selected such that a non-ejection pulse is added during predetermined printing. Further, when the ejection pulse for ejecting the droplet is not output at the time of the next printing after the predetermined printing, the combination of the drive waveforms is selected so that the non-ejection pulse is not added at the time of the predetermined printing. Then, printing is performed based on the combination of the ejection pulse and the non-ejection pulse.

  Print cycle that shows the waveform selection status when the current is ejection and the next is ejection (when droplets are being ejected at the current printing and when droplets are ejected at the current next printing) The switches of the ejection pulse part in the first half in the middle and the non-ejection pulse part in the latter half of the printing cycle are kept ON. At this time, the drive waveform is applied to the ejection pulse portion in the first half of the printing cycle, and the drive waveform is also applied to the non-ejection pulse portion in the second half of the printing cycle.

  When the current is ejection and the next is non-ejection (when droplets are ejected at the time of the current printing, when droplets are not ejected at the current next printing) The switch of the discharge pulse part in the first half in the cycle is turned on, and the switch in the non-discharge pulse part in the second half of the printing cycle is turned off. At that time, the drive waveform is applied in the first half of the ejection pulse portion in the printing cycle, and the drive waveform is not applied in the second half of the non-ejection pulse portion in the printing cycle, and maintains a high level.

  When the current is non-ejection, the next is ejection (when droplets are not ejected at the time of the current printing, and when droplets are ejected at the time of the next next printing), printing that shows the waveform selection status The switch of the ejection pulse part in the first half in the cycle is turned off, and the switch in the non-ejection pulse part in the latter half of the printing cycle is turned on. At this time, the applied waveform is maintained at a high level without being applied to the drive pulse in the first half of the ejection pulse portion in the printing cycle, and is applied to the non-ejection pulse portion in the second half of the printing cycle.

  Indicates the waveform selection status when the current is non-ejection and the next is non-ejection (when no droplet is ejected at the time of the current printing and when no droplet is ejected at the current next printing) The switches of the ejection pulse part in the first half during the printing cycle and the non-ejection pulse part in the second half during the printing cycle are kept off. At this time, the applied waveform continues to be maintained at a high level without applying the drive waveform even in the first half of the ejection pulse portion in the printing cycle and in the second half of the non-ejection pulse portion in the printing cycle.

  Another example is shown.

  As shown in FIG. 7, FIG. 7 is an example of a drive waveform applied to the actuator 307 (see FIG. 3) in FIG. 4, and in the same manner as in FIG. The pulse part is shown. As in FIG. 8, the predetermined printing time is set as the current printing time as the reference printing time, and the combination of the drive waveforms is selected depending on whether or not the non-ejection pulse is added to the ejection pulse.

  Print cycle that shows the waveform selection status when the current is ejection and the next is ejection (when droplets are being ejected at the current printing and when droplets are ejected at the current next printing) The switches of the ejection pulse part in the first half in the middle and the non-ejection pulse part in the latter half of the printing cycle are kept ON. At that time, a drive waveform is applied (changed to a low level) in the first half of the ejection pulse portion in the printing cycle, and a driving waveform is also applied in the second half of the non-ejection pulse portion in the printing cycle.

  When the current is ejection and the next is non-ejection (when droplets are ejected at the time of the current printing, when droplets are not ejected at the current next printing) The switch of the discharge pulse part in the first half in the cycle is turned on, and the switch in the non-discharge pulse part in the second half of the printing cycle is turned off. At this time, the drive waveform is applied to the discharge pulse portion in the first half of the printing cycle, and the drive waveform is not applied to the non-discharge pulse portion in the second half of the print cycle, and maintains a high level (charged state).

  When the current is non-ejection (no droplets are ejected at the time of the current printing, the first half of the ejection pulse part in the printing cycle showing the waveform selection state, and the second half of the non-ejection pulse part switch in the printing cycle) In this case, the applied waveform continues to be maintained at a high level without being applied to the drive waveform even in the first half of the ejection pulse portion in the printing cycle and in the second half of the non-ejection pulse portion in the printing cycle.

  In the first embodiment of the present invention, the head controller 170 (see FIG. 4) determines data. When the head controller 170 (see FIG. 4) determines the data, the head controller 170 (see FIG. 4) creates data indicating which part of the waveform generated in advance is applied to the actuator 307 (see FIG. 3). This means that the SWIC 434 (see FIG. 4) is controlled. In addition, at the start and end of printing, charging or discharging up to a bias potential is performed. Further, except for the printing state (pause state = pause when there is no print data), the drive waveform is set to 0 V, and all the SWICs 434 (see FIG. 4) are controlled to be open. Furthermore, the first half of the printing cycle is set so that the length of the first half of the printing cycle (ejection pulse part of the first half of the printing cycle) + the latter half of the printing cycle (non-ejection pulse part of the second half of the printing cycle) falls within the printing cycle. Alternatively, the second half may be determined from the length of the driving waveform or the pressure chamber 304 (the natural period of the actuator 307 (see FIG. 3) of the droplet ejector 224 (see FIG. 3)). A plurality of drive waveform generation circuits 433 (see FIG. 4) are prepared when gradation (dot diameter modulation) is performed or when a waveform matching the characteristics of each droplet ejector 224 (see FIG. 3) is applied. An arbitrary waveform may be selected.

  Therefore, there is no need for complicated logical operations, and since the ejection is controlled by the print data at the time of current printing and the non-ejection pulse is controlled by the next print data at the time of current printing, it is realized with a simple configuration and the drive waveform The number is reduced, and the ejection stability during continuous ejection is ensured.

  For example, as shown in the drive waveform of FIG. 8, when the print data at the next timing is ejection, the print data at the next timing becomes the data of the non-ejection pulse portion in the latter half of the printing cycle, and the non-ejection pulse Therefore, no arithmetic circuit is required and the number of pulse applications can be reduced, so that the power can be reduced.

  Furthermore, according to the driving waveform of FIG. 7, when a droplet is being ejected, a non-ejection pulse is added if the next droplet is ejected, and if there is no next droplet ejection, Since it is determined not to be added, the number of pulses is greatly reduced, resulting in low power consumption.

  Even when non-printing continues, a non-ejection pulse may be applied instead of the ejection pulse in the first half of the printing cycle, and the droplet in the droplet ejector 224 (see FIG. 3) is agitated. Yes. Further, since the non-ejection pulse in the second half of the printing cycle is the timing for suppressing the reverberation with respect to the non-ejection pulse in the first half of the printing cycle, abnormal ejection does not occur. In addition, the non-ejection pulse applied in the case of non-ejection and the non-ejection pulse for suppressing reverberation following the ejection pulse have been described as being the same, but different waveforms may be used depending on the situation and application. Further, as the non-ejection pulse, only the pulse width is adjusted and the waveform does not lead to ejection, but if there is an effect of suppressing reverberation, the non-ejection pulse may have a pulse width smaller than that of the ejection pulse. As described above, the non-ejection pulse may use a waveform having a smaller voltage amplitude than the ejection pulse. In addition, when the environment changes, the droplet viscosity changes especially with respect to the temperature. Therefore, at least one of the amplitude, pulse width, and pulse interval of the ejection pulse and non-ejection pulse is changed (adjusted) according to the changing droplet viscosity. By doing so, stable ejection (droplet diameter and droplet speed is constant) is always performed. Furthermore, as shown in FIG. 17, in order to cope with variations in the actuator 307 (see FIG. 3), three types of waveforms are generated and combined with the drive waveforms in FIGS. 7 to 10, thereby the actuator 307 (see FIG. 3). Thus, the application of the reverberation suppression pulse is stabilized, and the drive waveform is made more efficient, thereby saving power. The ejection pulse is a pulse for ejecting droplets when there is print data, and is a non-ejection pulse when there is no print data.

  As shown in FIG. 5, a second drive device 500 that is a modification of the first drive device 400 (see FIG. 4) includes a drive waveform generation circuit 533, a SWIC 534, and a head controller 170.

  The drive waveform generation circuit 533 has three waveform generation circuits in order to generate a plurality of types of waveforms. Further, the SWIC 534 switches the drive waveform supplied to the actuator 307 (see FIG. 3) provided in each droplet ejector 224 (see FIG. 3). Furthermore, the head controller 170 includes a storage unit in which data necessary for driving the drive waveform generation circuit 533 is stored in advance, and controls the driving of each unit and the exchange of various signals.

  In the droplet discharge head 211 (see FIG. 2), waveform data corresponding to droplets (large droplets, medium droplets, and small droplets) having different droplet diameters are given to these three waveform generation circuits, so that three types of driving waveforms are obtained. Can be generated simultaneously and droplets with three different droplet sizes can be printed simultaneously (gradation printing). This waveform data is stored in the storage unit of the head controller 170 and is given to each waveform generation circuit 533 by the head controller 170. The storage unit of the head controller 170 also stores non-ejection pulses (reverberation suppression pulses).

  The drive waveform generation circuit 533 is connected to an actuator 307 (see FIG. 3) provided in each droplet ejector 224 (see FIG. 3) by a signal line. In order to supply any one of the different drive waveforms generated by the three waveform generation circuits to the actuator 307 (see FIG. 3), each signal line and the actuator 307 (see FIG. 3) A switch 537 is provided between them. By switching the switch 537 ON or OFF, one drive waveform is selected and supplied to each actuator 307 (see FIG. 3) from the drive waveforms generated by the three waveform generation circuits. The switch 537 is turned on or off by the waveform selection circuit 536 of the SWIC 534 based on a command signal from the head controller 532, and the drive of each actuator 307 (see FIG. 3) is controlled.

  As shown in FIG. 9, FIG. 9 is an example of a drive waveform applied to the actuator 307 (see FIG. 3) in FIG. 5, and the first half of the printing cycle shows the ejection pulse portion in the printing cycle. In the second half of the printing cycle, the non-ejection pulse portion is shown. In the drive waveform 1, the drive waveform is applied to both the first-half ejection pulse portion in the printing cycle and the second-half non-ejection pulse portion in the printing cycle (the next ejection is based on the current printing time). ). Further, in the drive waveform 2, the drive waveform is applied to the first ejection pulse portion in the printing cycle, and the drive waveform is not applied to the second non-ejection pulse portion in the printing cycle (current printing time). There is no next discharge based on In drive waveform 3, the drive waveform is not applied to the first half of the ejection pulse portion in the printing cycle, and the drive waveform is applied to the second half of the non-ejection pulse portion in the printing cycle (current printing). The next discharge is based on time).

  When the current is ejection and the next is ejection (when droplets are ejected at the time of the current printing and when droplets are ejected even at the time of the next next printing), the waveform 1SW indicating the waveform selection state ( The drive waveform 1 SW (switch) is turned on, and the waveform 2 SW (drive waveform 2 switch) and the waveform 3 SW (drive waveform 3 switch) are both turned off. At this time, as shown in the driving waveform 1, the applied waveform is applied to the first ejection pulse portion, and the driving waveform is also applied to the second non-ejection pulse portion.

  Waveform indicating the waveform selection status when the current is ejection and the next is non-ejection (when droplets are ejected during the current printing and when no droplets are ejected during the current next printing) 2SW is turned ON, and both waveform 1SW and waveform 3SW are turned OFF. At this time, the applied waveform is applied to the ejection pulse portion in the first half of the printing cycle, and is maintained at a high level without being applied to the non-ejection pulse portion in the second half of the printing cycle.

  When the current state is non-ejection (when liquid droplets are not ejected at the time of the current printing), the waveform 1SW, the waveform 2SW, and the waveform 3SW indicating the waveform selection state are all turned OFF. At this time, the applied waveform continues to be maintained at a high level without applying the drive waveform even in the first half of the ejection pulse portion in the printing cycle and in the second half of the non-ejection pulse portion in the printing cycle.

  FIG. 10 shows an example of a drive waveform applied to the actuator 307 (see FIG. 3) in FIG. 5, and shows the ejection pulse portion and the non-ejection pulse portion in the printing cycle as in FIG. Yes. Further, the drive waveform 1, the drive waveform 2, and the drive waveform 3 are set in the same manner as in FIG.

  Waveform 1SW indicating the waveform selection state when the current is ejection and the next is ejection (when droplets are ejected at the time of the current printing and when droplets are ejected even at the time of the next next printing) Is turned on, and both the waveform 2SW and the waveform 3SW are turned off. At this time, as shown in the driving waveform 1, the applied waveform is applied to the first ejection pulse portion, and the driving waveform is also applied to the second non-ejection pulse portion.

  Waveform indicating the waveform selection status when the current is ejection and the next is non-ejection (when droplets are ejected during the current printing and when no droplets are ejected during the current next printing) 2SW is turned ON, and both waveform 1SW and waveform 3SW are turned OFF. At this time, the applied waveform is applied to the ejection pulse portion in the first half of the printing cycle, and is maintained at a high level without being applied to the non-ejection pulse portion in the second half of the printing cycle.

  Waveform indicating the waveform selection status when the current is non-ejection and the next is ejection (when droplets are not ejected at the time of current printing and when droplets are ejected at the time of the next next printing) 1SW and waveform 2SW are turned off, and waveform 3SW is turned on. At this time, the applied waveform is maintained at a high level without being applied to the drive pulse in the first half of the ejection pulse portion in the printing cycle, and is applied to the non-ejection pulse portion in the second half of the printing cycle.

  Indicates the waveform selection status when the current is non-ejection and the next is non-ejection (when no droplet is ejected at the time of the current printing and when no droplet is ejected at the current next printing) Waveform 1SW, waveform 2SW, and waveform 3SW are all OFF. At this time, the applied waveform continues to be maintained at a high level without applying the drive waveform even in the first half of the ejection pulse portion in the printing cycle and in the second half of the non-ejection pulse portion in the printing cycle.

In addition, when outputting a discharge pulse for discharging a droplet for printing at the time of the next printing after a predetermined printing with reference to a predetermined printing time, a non-discharge pulse is not added and a discharge pulse is not output. In some cases, the operation of adding a non-ejection pulse can be said to be an operation of prefetching print data obtained later.
(Second Embodiment)
As shown in FIG. 11, the third drive device 1100 includes a variable power source 1133, a SWIC 1134, and a head controller 170.

  The variable power source 1133 generates a variable voltage. Further, the SWIC 1134 holds, in a memory, drive waveform data to be supplied to an actuator 307 (see FIG. 3) provided in each droplet ejector 224 (see FIG. 3) (a memory unit is not shown). Each time (see FIG. 3), the drive waveform is applied to the actuator 307 (see FIG. 3) by controlling on / off of the SW 1137 connected to the variable power source and GND. Further, the head controller 170 receives input data for controlling the variable power source 1133, for example, temperature data. In addition, it includes a storage unit in which drive waveform data is stored in advance, and controls the exchange of signals with the memory unit of the SWIC 1134 as needed.

  In the droplet discharge head 211 (see FIG. 2), drive waveform data corresponding to droplets (large droplets, medium droplets, and small droplets) having different droplet diameters is transmitted to the SWIC 1134 in advance, and the waveform selection circuit 1136 performs SW1137. By appropriately controlling, a drive waveform can be generated to print droplets having different droplet diameters (gradation printing). The waveform data is stored in the storage unit of the SWIC 1134 transmitted from the head controller 170, and the drive waveform is applied to the actuator 307 (see FIG. 3) by controlling the SW 1137 by the waveform selection circuit 1136. The storage unit of the SWIC 1134 transmitted from the head controller 170 also stores waveform data without droplet discharge, which is also called a non-ejection pulse or a reverberation suppression pulse.

  The variable power source 1133 is connected to an actuator 307 (see FIG. 3) provided in each droplet ejector 224 (see FIG. 3) by a signal line. A switch 1137 is provided between each signal line and the actuator 307 (see FIG. 3) in order to supply the voltage generated by the variable power supply 1133 to the actuator 307 (see FIG. 3) as a drive waveform. By switching the switch 1137 ON or OFF, a voltage generated by the variable power source 1133 is supplied as a drive waveform to each actuator 307 (see FIG. 3). Switching of each switch 1137 is turned on or off by the waveform selection circuit 1136 of the SWIC 1134 based on a command signal from the head controller 170, thereby controlling the driving of each actuator 307 (see FIG. 3).

  As shown in FIG. 12, the circuit block diagram 1200 includes a first shift register 1220, a second shift register 1230, a first latch circuit 1240, a second latch circuit 1250, a logic circuit 1270, and a waveform memory 1260. .

  The first shift register 1220 stores i-th data. The second shift register 1230 stores the (i−1) th data. Further, the first latch circuit 1240 stores data stored in the first shift register 1220. The second latch circuit 1250 stores the data stored in the second shift register 1230. Further, the waveform memory 1260 stores the waveforms of FIGS. 13 and 14 including the timing of hitting large droplets, medium droplets, small droplets, and the timing of ejecting droplets.

  In the circuit block 1200, ON or OFF data corresponding to the image data is transferred from the upper level, the data is stored in the SWIC 1134 (see FIG. 11), and a logical operation is performed to the actuator 307 (see FIG. 3). Generate an applied waveform.

  As shown in FIG. 13, FIG. 13 is an example of a drive waveform applied to the actuator 307 (see FIG. 3) in FIGS. Also, when the specified printing time is set as the current printing time (current printing time) as the reference (during standard printing time), and the discharge pulse for printing is output by discharging liquid droplets at the next printing time after the predetermined printing time. For this, a combination of drive waveforms is selected such that a non-ejection pulse is added during predetermined printing. Further, when the ejection pulse for ejecting the droplet is not output at the time of the next printing after the predetermined printing, the combination of the drive waveforms is selected so that the non-ejection pulse is not added at the time of the predetermined printing. Then, printing is performed based on the combination of the ejection pulse and the non-ejection pulse.

  As an example of the drive waveform, in the printing cycle, the first half of the printing cycle indicates the ejection pulse portion, and the second half of the printing cycle indicates the non-ejection pulse portion. In the ejection pulse part in the first half of the printing cycle, the SW (switch) is controlled with the current data (the switch is controlled depending on whether or not droplets are ejected during the current printing), and the non-ejection pulse in the second half of the printing cycle. In the unit, the SW is controlled by the next data after the current data (the switch is controlled depending on whether or not the droplet is ejected at the time of the next printing at the time of the current printing).

  When the current is ejection and the next is ejection (when droplets are ejected at the time of the current printing and when droplets are ejected even at the time of the next next printing), the applied waveform is A drive waveform is applied in the first half of the ejection pulse portion, and a drive waveform is also applied in the second half of the non-ejection pulse portion in the printing cycle.

  If the current is ejection and the next is non-ejection (when droplets are ejected at the time of the current printing and no droplets are ejected (non-ejection) at the time of the current next printing), The applied waveform is applied to the drive waveform in the first half of the ejection pulse portion in the printing cycle, and is maintained at the high level without being applied to the non-ejection pulse portion in the second half of the printing cycle.

  When the current is non-ejection (when the droplet is not ejected at the time of the current printing), the applied waveform is the drive waveform even in the first half of the ejection pulse part in the printing cycle and the second half of the non-ejection pulse part in the printing cycle Is maintained at a high level without being applied.

  Since the drive waveform is generated by fine control of the high-level side switch and the low-level side switch, any form can be used here as long as the control is possible.

  14 shows an example of a drive waveform applied to the actuator 307 (see FIG. 3) in FIGS. 11 and 12 as in FIG. 13, and the first half of the printing cycle is the ejection pulse in the printing cycle. The second half of the printing cycle indicates a non-ejection pulse portion.

  In the discharge pulse part in the first half of the printing cycle, the SW is controlled with the current data (the switch is controlled depending on whether or not droplets are discharged during the current printing), and in the non-ejection pulse part in the second half of the printing cycle, The SW is controlled by the next data after the current data (the switch is controlled depending on whether or not the droplet is ejected at the time of the next printing at the time of the current printing).

  When the current is ejection and the next is ejection (when droplets are ejected at the time of the current printing and when droplets are ejected even at the time of the next next printing), the applied waveform is A drive waveform is applied in the first half of the ejection pulse portion, and a drive waveform is also applied in the second half of the non-ejection pulse portion in the printing cycle.

  When the current is ejection and the next is non-ejection (when droplets are ejected during the current printing and when no droplets are ejected during the current next printing), the applied waveform is the printing cycle The drive waveform is applied in the first half of the ejection pulse part, and the drive waveform is not applied in the second half of the non-ejection pulse part in the printing cycle, and the high level is maintained.

  When the current is non-ejection and the next is ejection (when droplets are not ejected at the time of current printing and when droplets are ejected at the time of the next next printing), the applied waveform is the printing cycle The driving waveform is maintained at a high level without being applied in the first half of the ejection pulse portion, and the driving waveform is set in the second half of the non-ejection pulse portion in the printing cycle.

  When the current is non-ejection and the next is non-ejection (when droplets are not ejected at the time of current printing and when droplets are ejected even at the time of the next next printing), the applied waveform is printed In the first half of the ejection pulse part in the cycle and the second half of the non-ejection pulse part in the printing cycle, the drive waveform is not applied and the high level is maintained.

  Since the drive waveform is generated by fine control of the high-level side switch and the low-level side switch, any form can be used here as long as the control is possible. In addition, when outputting a discharge pulse that discharges droplets for printing at the time of the next printing after a predetermined printing, the non-discharge pulse is not added and the discharge pulse is not output. In some cases, the operation of adding a non-ejection pulse can be said to be an operation of prefetching print data obtained later.

  The operation of the second embodiment will be described below.

  As shown in FIG. 15, the flow of the data signal will be described in the order of the (i-1) th data (data), the ith data, and the i + 1th data of the data signal with reference to the waveform selection circuit 1136 of FIG. To do.

  At the time of current printing, the (i-1) th data is sent from the host based on the latch signal. Specifically, the (i-1) th data is data that has been sent through the first shift register 1220 and the second shift register 1230 previously. At this time, the applied waveform controls the charge SW or discharge SW of the ejection pulse based on the i-3th data. The applied waveform controls the charge SW or discharge SW of the non-ejection pulse based on the i−2th data. Note that the current printing data (i-1th data) is stored in the second shift register 1230, and the current printing data (ith data) is the first shift register 1220. Stored in In addition, the current printing data (i-2th data) is stored in the second latch circuit 1250, and the current printing data (i-1th data) is the first data. 1 latch circuit 1240. Further, the data signal passes through the wiring (1), the wiring (2), the wiring (3) of the second latch circuit 1250, and the wiring (1), the wiring (2), and the wiring (3) of the first latch circuit 1240. Are transmitted to the logic circuit 1270, and a drive waveform is output based on the waveform memory 1260.

  Furthermore, at the time of the next printing now, the i-th data is sent from the host based on the latch signal. In this case, the applied waveform controls the discharge pulse charge SW or discharge SW based on the (i-2) th data, and controls the non-discharge pulse charge SW or discharge SW based on the (i-1) th data. Do.

  Further, at the time of the next printing at the current next printing, the (i + 1) th data is sent from the host based on the latch signal. In this case, the applied waveform controls the discharge pulse charge SW or discharge SW based on the (i-1) th data, and controls the non-discharge pulse charge SW or discharge SW based on the i-th data.

  In the subsequent printing, the same control is sequentially performed.

  Note that the data of the data signal and the data of the applied waveform in FIG. 15 are units of SWIC 1134 (see FIG. 11), not data for one dot. For example, in the case of 256 nozzles, data for 256 nozzles. Is used.

  Further, as shown in FIG. 16, this is a seventh example of ejection pulses and non-ejection pulses applied to the actuator 307 (see FIG. 3), and the amplitude of the non-ejection pulses in the latter half of this printing cycle is a plurality of droplets. You may change small according to each meniscus vibration of the ejector 224 (refer FIG. 3).

  Further, as shown in FIG. 17, an example is shown in which three types of waveforms are generated in order to cope with variations in the actuator 307 (see FIG. 3). Further, by combining with the drive waveforms in FIGS. 7 to 10, 13, and 14, countermeasures for individual variations of the actuator 307 (see FIG. 3), stabilization of reverberation suppression pulse application, and drive waveform efficiency can be improved. This can be realized to save power.

  In the case of the second embodiment of the present invention, the SWIC 1134 (see FIG. 11) makes a judgment. From the upper level, ON or OFF data corresponding to the image data is transferred to the SWIC 1134 (see FIG. 11). This means that a waveform applied to the actuator 307 (see FIG. 3) is generated by accumulating data and performing a logical operation. More specifically, the head controller 170 (see FIG. 11) generates a constant voltage from the head information, environmental information, and the like, and transfers the print data to the SWIC 1134, thereby controlling the charge / discharge SW and discharging. .

  The SWIC 1134 (see FIG. 11) is a waveform memory in which the shift register, the latch circuit, the logic circuit, the discharge switch, the charge switch, the discharge switch, and the timing for turning on or off the charge switch are stored. 1260 (see FIG. 12). This data (data of timing for turning on or off the discharge SW and the charge SW) is transferred from the head controller 1134 to the SWIC 1134 in advance, and data that can generate at least ejection pulses and non-ejection pulses is recorded.

  11 and 12 show only the minimum necessary circuit configuration, and a decoder, level shifter, and the like are included in the logic circuit 1270. FIG. Furthermore, the head controller 1134 transfers print data together with a clock signal to the SWIC 1134 for each ejection cycle, and sends a latch signal. Then, when the i-th ejection data is transferred and the data is captured by the latch signal, the SWIC 1134 holds the i-1th data and the i-th data transferred at the previous timing.

  First, when the i-th print data is ejection, the ejection pulse data is read from the memory, the charge SW and the discharge SW are controlled, and the ejection pulse is applied to the actuator 307 (see FIG. 3). Next, based on the i-th print data, data is read from the waveform memory 1260 (see FIG. 12) so that a non-ejection pulse is applied to the actuator 307 (see FIG. 3), and either the charge SW or the discharge SW is read out. Control.

  Note that, when the print data for the (i-1) th time is non-ejection, a non-ejection pulse may be applied. Further, even when non-printing continues, the droplets in the droplet ejector 224 (see FIG. 3) are agitated. Further, since the non-ejection pulse in the second half of the printing cycle is the timing for suppressing the reverberation with respect to the non-ejection pulse in the first half of the printing cycle, abnormal ejection does not occur. In addition, the non-ejection pulse applied in the case of non-ejection and the non-ejection pulse following the ejection pulse for reverberation suppression are described as being the same, but different waveforms may be used depending on the situation and application. Further, as the non-ejection pulse, only the pulse width is adjusted and the waveform does not lead to ejection, but if there is an effect of suppressing reverberation, the non-ejection pulse may have a pulse width smaller than that of the ejection pulse. As described above, the non-ejection pulse may use a waveform having a smaller voltage amplitude than the ejection pulse. Further, the SWIC 1134 is not limited to this configuration. For example, any configuration can be used as long as it can store print data for two times, such as a shift register for one time, a latch circuit for two times, and a configuration for alternately storing data. A simple circuit configuration may be used. Furthermore, when the environment changes, the droplet viscosity changes with temperature in particular, so at least one of the amplitude, pulse width, and pulse interval of the ejection pulse and non-ejection pulse is changed (adjusted) according to the changing droplet viscosity. By doing so, stable ejection (droplet diameter and droplet speed is constant) is always performed. In addition, as shown in FIG. 17, in order to cope with variations in the actuator 307 (see FIG. 3), three types of waveforms are generated and combined with the drive waveforms in FIGS. 13 and 14, whereby the actuator 307 (see FIG. 3). In this way, the application of the reverberation suppression pulse is stabilized, and the drive waveform is made more efficient, thereby reducing power consumption. The ejection pulse is a pulse for ejecting droplets when there is print data, and a non-ejection pulse when there is no print data.

  Therefore, when a droplet is ejected at the time of current printing, a non-ejection pulse is added if there is a next droplet ejection, and a non-ejection pulse is not added if there is no next droplet ejection. Therefore, the number of pulses is greatly reduced and the power is reduced.

In addition, at the time of current printing, when no droplet is ejected, if the next droplet is ejected, a non-ejection pulse is added, and if there is no next droplet ejection, no non-ejection pulse is added. Control is simplified. In the current printing, reverberation is suppressed when a droplet is ejected next, and thickening is prevented when a droplet is not ejected.
(Third embodiment)
The third embodiment of the present invention will be described below.

  The third embodiment relates to the operation (printing control) of the drive waveform pulse employed in the first embodiment and the second embodiment, and the first embodiment and the second embodiment. The same components as those described in the embodiment are denoted by the same reference numerals, and the components are omitted.

  As shown in FIG. 18, the droplet discharge head 1800 includes a flexible printed circuit board (hereinafter referred to as FPC (Flexible Printed Circuits)) 1810, a switching IC (hereinafter referred to as SWIC) 1820, a manifold 1830, a stack 1840, and a liquid. The droplet supply port 1850 is configured.

  The FPC 1810 is a flexible substrate that can be largely deformed, and can be repeatedly deformed with a small force, and maintains its electrical characteristics even when deformed. For example, the FPC 1810 has an adhesive layer formed on a film-like insulator (base film) having a thickness of 12 μm to 50 μm, and further a conductor foil having a thickness of about 12 μm to 50 μm is formed thereon, except for the terminal portion and the soldered portion. The structure is covered with an insulator. Further, the SWIC 1820 performs control to generate a drive waveform to be supplied to the actuator 307 (see FIG. 3) provided in each droplet ejector 224 (see FIG. 3). Further, the manifold 1830 divides the flow path or connects a plurality of flow paths to collect a plurality of flow paths or connections, shortens the flow path to reduce space, Forming a road. The stack 1840 is formed by laminating a nozzle 302 (see FIG. 3), a pressure chamber 304 (see FIG. 3), a nozzle plate 303 (see FIG. 3), a polyimide film, an actuator 307 (see FIG. 3), and the like. Yes. Further, the droplet supply port 1850 is a supply port for supplying droplets from a droplet tank (not shown). Note that a plurality of SWICs 1820 are provided on the FPC 1810, and the electrodes of the actuator 307 (see FIG. 3) and the SWICs 1820 are connected by wiring in the FPC 1810.

  As shown in FIG. 19, the arrangement diagram 1900 of the droplet discharge head 1800 (see FIG. 18) is a view of the stack 1840 (see FIG. 18) as viewed from the direction of the nozzle 302, and the nozzle 302 and the stack 1840 (FIG. 18). Reference).

  A plurality of droplet ejection heads 1800 (see FIG. 18) are arranged in a direction perpendicular to the printing direction (three in FIG. 19), and the printing area of the recording paper, which is a recording medium, is expanded to the paper width by one scan. Perform high-speed printing along the printing direction.

  Conventionally, for each nozzle 302 (see FIG. 3), the drive waveform of the droplet discharge head 1800 (see FIG. 18) corresponding to each gradation is selected from a plurality of drive waveform patterns and is based on a correspondence table. Thus, correction has been performed for each nozzle 302 (see FIG. 3).

  However, in order to perform more detailed correction, it is better that the number of drive waveform patterns for correction (number of drive waveform patterns) is larger, but the amount of correction data increases as the drive circuit becomes larger.

  Accordingly, since the number of drive waveform patterns is limited, when the purpose is to perform the most effective correction with a limited number of drive waveform patterns, the object is achieved by the following third embodiment.

  As shown in FIG. 20, the SWIC 1820 (see FIG. 18) is provided corresponding to the shift register 2040, the latch circuit 2042, and the drive waveforms that can be generated (16 in the third embodiment of the present invention). , 2044 (16), selectors 2046 (1),..., 2046 (n) provided for each of the nozzles 302 (see FIG. 3), level shifters 2048 (1),. ), And a drive waveform generation circuit 2050 (1),..., 2050 (n). Note that n is an integer of 1 or more.

  The clock signal and the drive waveform selection signal output from the information processing unit 140 (see FIG. 1) are input to the shift register 2040, and the latch signal is input to the latch 2042.

  The drive waveform selection signal is a signal for selecting any one of 16 types of drive waveform patterns generated by the information processing unit 140 (see FIG. 1) based on the image data. The drive waveform selection signal is serial data composed of a plurality of bits, and the drive waveform selection signal is continuously input to the shift register 2040 by the number of droplet ejectors 224 (see FIG. 3).

  The shift register 2040 converts the input serial data drive waveform selection signal into parallel data and outputs the parallel data to the latch 2042. The latch 2042 latches (holds or stores) the parallel data input from the shift register 2040 according to the input of the latch signal.

  Each of the shift registers 2044 (1),..., 2044 (16) receives a pattern of the first drive waveform from the pattern of the first drive waveform from the information processing unit 140 (see FIG. 1).

  The selectors 2046 (1),..., 2046 (n) select one drive waveform pattern from a plurality of types of drive waveform patterns according to the drive waveform selection signal input via the shift register 2040 and the latch 2042. The drive waveform pattern selected by the drive waveform selection signal is shifted in timing according to the arrangement of the nozzles 302 (see FIG. 3) by the shift registers 2044 (1),..., 2044 (16), and the selector 2046 (1),. , 2046 (n). Then, the level is converted by the level shifters 2048 (1),..., 2048 (n) and output to the drive waveform generation circuits 2050 (1),.

  On the other hand, the drive waveform generation circuits 2050 (1),..., 2050 (n) are supplied with power at a voltage level of the DC voltage HV1 and the DC voltage HV2 from a power supply unit (not shown).

  The drive waveform generation circuits 2050 (1),..., 2050 (n) include the first signal generation circuits 2051 (1),..., 2051 (n) and the second signal generation circuits 2054 (1),. ) And third signal generation circuits 2053 (1),..., 2053 (n). The first signal generation circuits 2051 (1),..., 2051 (n) and the second signal generation circuits 2054 (1),..., 2054 (n) are P-channel MOS field effect transistors. Reference numerals 2053 (1),..., 2053 (n) are N-channel MOS field effect transistors.

  The first signal generation circuits 2051 (1),..., 2051 (n) and the second signal generation circuits 2054 (1),..., 2054 (n) are respectively PMOSFETs (P-channel Metal Oxide Field Effect Transistors). 2051 (1),..., 2051 (n). In addition, the third signal generation circuits 2053 (1),..., 2053 (n) are referred to as NMOSFET (N-channel Metal Oxide Field Effect Transistor) 2053 (1),.

  The power source of the voltage level HV1 is supplied to the source side of the PMOSFETs 2051 (1),..., 2051 (n) which are the first signal generation circuits 2051 (1),. The power source of the voltage level HV2 is supplied to the source side of the PMOSFETs 2054 (1),..., 2054 (n) which are the second signal generation circuits 2054 (1),. The source sides of the NMOSFETs 2053 (1),..., 2053 (n) that are the third signal generation circuits 2053 (1),..., 2053 (n) are grounded to the ground level. , 2051 (n), PMOSFET 2054 (1),..., 2054 (n) and NMOSFET 2053 (1),..., 2053 (n) are provided with level shifters 2048 (1),. The output terminal (n) is connected. The drain side of each signal generation circuit is connected to one point and is connected to the actuator 307 (see FIG. 3). Note that the inverter circuits 2052 (1),..., 2052 (n) are connected by connecting the drain sides of the PMOSFETs 2051 (1),..., 2051 (n) and the drain sides of NMOSFETs 2053 (1),. It is composed.

  In this drive waveform generation circuit 2050 (1),..., 2050 (n), based on the drive waveform pattern inputted from the level shifters 2048 (1),. A drive waveform pattern having a ternary voltage level of the voltage level of the voltage HV1 and the voltage level of the DC voltage HV2 is generated and applied to the actuator 307 (see FIG. 3).

  Waveform data from which the drive waveform pattern is generated is stored in advance in a storage device (for example, ROM 146 (see FIG. 1) or HDD 150 (see FIG. 1)). In the information processing unit 140, the CPU 144 generates a drive waveform pattern based on the waveform data of the drive waveform pattern stored in the storage device, and supplies the drive waveform pattern to the SWIC 1820 (see FIG. 18).

  In the third embodiment of the present invention, waveform data of a drive waveform pattern is prepared so that three types of droplets having different droplet volumes can be ejected. Specifically, the three types of droplets are referred to as a large droplet, a medium droplet, and a small droplet in descending order of droplet volume. Note that the DC voltage HV1 and the DC voltage HV2 are supplied to the SWIC 1820 (see FIG. 18) and connected to a ground (hereinafter referred to as GND). When the three switching elements (for example, 2051 (n), 2053 (n), and 2054 (n)) corresponding to the DC voltage HV1, the DC voltage HV2, and the GND are turned on or off, a driving waveform pattern 3 is obtained. A digital waveform of the value is applied to an actuator 307 (see FIG. 3) that is a piezoelectric element. Also, 16 types of drive waveform pattern data (drive waveform data) are set in the SWIC 1820 (see FIG. 18), and one of them is selected and applied to the actuator 307 (see FIG. 3).

  The operation of the third embodiment of the present invention will be described below.

  As shown in FIGS. 21 (a) to 21 (d), each drive waveform pattern (preliminary, large droplet, medium droplet, and small droplet waveform) has a GND voltage level, a DC voltage HV1 voltage level, and a DC voltage. It is a ternary digital waveform of the voltage level of the voltage HV2, and is composed of a first pulse and a second pulse applied after the first pulse. There is also a drive waveform pattern that does not include the second pulse.

  T1 represents the pulse width T1 of the first pulse, T3 represents the pulse width T3 of the second pulse, and T2 represents the pulse interval. The rise time or fall time of the drive waveform pattern that is a digital waveform is determined by the capacitance of the actuator 307 (see FIG. 3) and the PMOSFET 2051 that constitutes the drive waveform generation circuits 2050 (1),..., 2050 (n). (1),..., 2051 (n), 2054 (1),..., 2054 (n) and NMOSFETs 2053 (1),.

  Furthermore, in the image forming apparatus 120 (see FIG. 1) according to the third embodiment of the present invention, the nozzle 302 (see FIG. 3) is in a non-ejection period in which no droplet is ejected from the nozzle 302 (see FIG. 3). A preliminary waveform (also referred to as a non-ejection pulse), which is a drive waveform pattern for driving the actuator 307 (see FIG. 3) to the extent that droplets are not ejected from the nozzle and changing the pressure in the pressure chamber 304 (see FIG. 3). It is prepared.

  By applying the preliminary waveform, the meniscus of the nozzle 302 (see FIG. 3) is vibrated to suppress the thickening (ink thickening) of the droplets around the nozzle 302 (see FIG. 3). Hereinafter, a non-ejection period during which no droplet is ejected is referred to as a non-ejection period.

  As shown in FIG. 21A, the preliminary waveform, which is a drive waveform pattern for suppressing the meniscus vibration of the droplet and agitating the droplet, has a small amplitude from the voltage level of the DC voltage HV1 to the voltage level of the DC voltage HV2. It is comprised by the 1st pulse which has. Since the amplitude of the first pulse of the preliminary waveform is relatively small, power consumption is small because the thickened droplet (thickened ink) is not stirred to the back of the nozzle 302 (see FIG. 3).

  The driving waveform pattern for ejecting the large droplet having the largest droplet volume is composed of the first pulse as shown in FIG. Although the second pulse is not included in the drive waveform pattern for ejecting large droplets, a voltage of the DC voltage HV2 is applied at the pulse interval T2 following the first pulse.

  As shown in FIG. 21C, a driving waveform pattern for ejecting a medium droplet having a middle size of the droplet volume is obtained by applying a first pulse and a pulse interval T2 after the application of the first pulse. From the second pulse applied.

  As shown in FIG. 21 (d), the driving waveform pattern for ejecting the droplet having the smallest droplet volume is applied after the first pulse and the pulse interval T2 after the application of the first pulse. However, the pulse interval T2 is shorter than that of the medium droplet driving waveform pattern.

  In order to discharge these droplets (large droplets, medium droplets, and small droplets), a predetermined pattern is driven to discharge large droplets, medium droplets, and small droplets to the droplet discharge head 1800 (see FIG. 18). In the waveform pattern, the pressure chamber 304 (see FIG. 3) is expanded by the fall of the first pulse, and the pressure chamber 304 (see FIG. 3) is contracted by the rise to discharge the droplet.

  Although not shown in the figure, the first pulse of the preliminary waveform is configured as shown in FIG. 21A by configuring the preliminary waveform with the first pulse having a large amplitude from the voltage level of the DC voltage HV1 to GND. Since the amplitude is larger than that of the first pulse of the preliminary waveform, the meniscus vibration amount is increased and the stirring ability of the droplet is also increased.

  Further, the waveform data that is the basis of the preliminary waveform is also stored in a storage device (for example, the ROM 146 (see FIG. 1) or the HDD 150 (see FIG. 1)).

  Note that the ternary digital waveform (preliminary waveform of driving waveform pattern, large droplet waveform, medium droplet waveform, and small droplet waveform) in FIG. 21 is the GND voltage level (ground level), the DC voltage HV1 voltage level, and It is a drive waveform pattern having a ternary voltage level of the DC voltage HV2.

  For example, a large droplet waveform, a medium droplet waveform, and a small droplet waveform eject droplets having a droplet volume of 10 pl, 6 pl, and 2.5 pl, respectively, and are used properly according to image data. In the preliminary waveform, the meniscus of the nozzle 302 (see FIG. 3) is vibrated to the extent that the droplet does not discharge, and the droplet is stirred. In addition, the preliminary waveform is applied to the nozzle 302 (see FIG. 3) without an ejection command, and suppresses the local increase in the viscosity of the droplet (for example, the increase in the viscosity of the ink). Further, the ejection data (image data) corresponding to one pixel is 2-bit data, and a preliminary waveform, a large droplet waveform, a medium droplet waveform, and a small droplet waveform are selected.

  In the 16 types of drive waveform patterns in the prior art of FIG. 22A, excluding the preliminary waveform, large droplet waveform 1 to large droplet waveform 5 (five waveforms), medium droplet waveform 1 to medium droplet waveform 5 (five waveforms). ), Droplet waveform 1 to droplet waveform 5 (five waveforms) were equally distributed.

  In the third embodiment of the present invention, the 16 types of drive waveform patterns in the high image quality mode of FIG. 22B are the large droplet waveform 1 to the large droplet waveform 3 (three waveforms), excluding the preliminary waveform, They are distributed as medium droplet waveform 1 to medium droplet waveform 5 (five waveforms) and droplet waveform 1 to droplet waveform 7 (seven waveforms).

  In the third embodiment of the present invention, 16 types of drive waveform patterns in the draft mode of FIG. 22C are the large droplet waveform 1 to the large droplet waveform 7 (seven waveforms), except for the preliminary waveform. The droplet waveform 1 to the medium droplet waveform 5 (five waveforms) and the droplet waveform 1 to the droplet waveform 3 (three waveforms) are distributed.

  In the high image quality mode, the number of drive waveform patterns is increased as the drop type has a smaller drop volume, and in the draft mode, the number of drive waveform patterns is increased as the drop type has a larger drop volume. Note that the draft mode is a mode that reduces the speed of the image data sent to the droplet discharge device by thinning out dots (in addition, character data, character image data, etc.) and reduces the consumption of droplets (ink). That is. Also, based on the sorting requirements including the liquid volume of the droplets (sorting the types of droplets in the high image quality mode or the draft mode), a predetermined number of driving waveform patterns are set, and a plurality of printing droplet modes, In addition, the drive waveform pattern is distributed to one non-printing mode.

  As shown in FIG. 23, correction data for each nozzle 302 (see FIG. 3) is set to any one of (1) to (7) as 3-bit data.

  Droplet discharge head 211 (see FIGS. 1 and 2) is printed with a large drop test chart, and the drop volume is calculated from the measurement result of the dot diameter of the test chart. Classify according to the results.

  The variation in droplet volume is highly correlated with large droplets, medium droplets, and small droplets, and the classification of large droplets can be applied to medium droplets and small droplets. Therefore, as shown in FIG. And the waveform of each drop type can be set.

  In (1) of the 3-bit data, the draft mode is set with 3-bit data of a large droplet waveform 1, a medium droplet waveform 1, and a small droplet waveform 1. In the high image quality mode, a large droplet waveform 1 and a medium droplet waveform 1 are set. And 3-bit data of the droplet waveform 1 is set.

  In (2) of the 3-bit data, the draft mode is set with 3-bit data of the large droplet waveform 2, the medium droplet waveform 2, and the small droplet waveform 1, and the large droplet waveform 1 and the medium droplet waveform 2 are set in the high image quality mode. , And 3 bit data of droplet waveform 2.

  In (3) of the 3-bit data, the draft mode is set with 3-bit data of a large droplet waveform 3, a medium droplet waveform 3, and a small droplet waveform 2. In the high image quality mode, a large droplet waveform 2 and a medium droplet waveform 3 are set. , And 3-bit data of the droplet waveform 3.

  In (4) of the 3-bit data, the draft mode is set with 3-bit data of the large droplet waveform 4, the medium droplet waveform 3, and the small droplet waveform 2, and in the high image quality mode, the large droplet waveform 2 and the medium droplet waveform 3 are set. , And 3 bit data of the droplet waveform 4.

  In (5) of the 3-bit data, the draft mode is set with 3-bit data of the large droplet waveform 5, the medium droplet waveform 3, and the small droplet waveform 2. In the high image quality mode, the large droplet waveform 2 and the medium droplet waveform 3 are set. , And 3 bit data of the droplet waveform 5.

  In (6) of the 3-bit data, the draft mode is set with 3-bit data of the large droplet waveform 6, the medium droplet waveform 4, and the small droplet waveform 3. In the high image quality mode, the large droplet waveform 3 and the medium droplet waveform 4 are set. , And 3 bit data of the droplet waveform 6.

  In (7) of the 3-bit data, the draft mode is set with 3-bit data of the large droplet waveform 7, the medium droplet waveform 5, and the small droplet waveform 3. In the high image quality mode, the large droplet waveform 3 and the medium droplet waveform 5 are set. , And 3-bit data of the droplet waveform 7 is set.

  These 3-bit data (1) to (7) are divided into five medium waveform waveforms and three small waveform waveforms in the high image quality mode, based on the seven large drive waveform patterns. Set them in correspondence with each other. Also, these 3-bit data (1) to (7) are based on the three drive waveform patterns of the large droplet waveform in the draft mode, and the five drive waveform patterns of the medium droplet waveform and the seven drives of the small droplet waveform. The waveform patterns are set in correspondence with each other. Then, based on the printing conditions (image quality mode, draft mode) including the image quality specified at the time of printing, the drive waveform pattern is selected and allocated as shown in 3-bit data (1) to (7). Change the distribution ratio.

  Accordingly, the correction data for each droplet type is uniquely determined based on the correction data having the largest number of drive waveform patterns.

  As shown in FIG. 24, the horizontal axis is the DC voltage HV1 [V], the vertical axis is the drop volume [pl], and the large, medium, and small drops when the voltage level of the DC voltage HV1 [V] is changed. The change in the amount of the drop volume [pl] is shown. The voltage level of the DC voltage HV2 is set so that DC voltage HV2 [V] −DC voltage HV1 [V] is always constant. In addition, among the changes in FIG. 24, the drop volume of the large, medium, and small droplets at which the DC voltage HV1 [V] at the broken line 2410 is 18 [V] is the first target (in the case of large droplets, 10 [pl In the case of medium drops, it is shown that the value is close to 6 [pl] and in the case of small drops, it is close to 2.5 [pl]).

  As shown in FIG. 25, the horizontal axis is the pulse width T1 [μsec], the vertical axis is the large drop volume [pl], and the large drop volume [pl] when the pulse width T1 [μsec] is changed. Shows the amount of change. 25, the drop volume of a large droplet having a pulse width T1 [μsec] at the broken line 2510 of 6.5 [μsec] is closest to the target (10 [pl] in the case of a large droplet). It is shown to take a value.

  As shown in FIG. 26, when the pulse interval T2 [μsec] is changed with the horizontal axis as the pulse interval T2 [μsec] and the vertical axis as the drop volume [pl] of the medium droplet and the small droplet, the medium droplet and the small droplet are changed. The change in the amount of the drop volume [pl] is shown. The pulse width T3 [μsec] is set so that the pulse interval T2 [μsec] + pulse width T3 [μsec] is always constant. In addition, among the changes in FIG. 26, the droplet volume of the droplet where the pulse interval T2 [μsec] at the broken line 2610 is 1.5 [μsec] is the first target (2.5 [pl] in the case of a droplet) It is shown to take a value close to. Furthermore, in the change of FIG. 26, the drop volume of the medium drop where the pulse interval T2 [μsec] at the broken line 2620 is 3.0 [μsec] is the first target (6.0 [pl] in the case of a medium drop). It is shown to take a value close to.

  As shown in FIG. 27, when the parameters of the drive waveform pattern of each droplet shown in FIG. 21 are set, 10 [pl] for large droplets, 6 [pl] for medium droplets, and 2.5 [pl] for small droplets The droplet ejector 224 is designed to be discharged.

  24, 25, and 26, the voltage level of the DC voltage HV1, the pulse width T1 [μsec] of the large droplet waveform, the pulse interval T2 [μsec] of the medium droplet waveform and the small droplet waveform, and the pulse By setting the width T3 [μsec], it is possible to correct the drive waveform pattern (large droplet waveform, medium droplet waveform, small droplet waveform) by each droplet.

  More specifically, in the case of a large droplet waveform, GND [V] is 0.0 V, DC voltage HV1 [V] is 18.0 [V], DC voltage HV2 [V] is 22.0 [V], pulse width It is ideal that T1 [μsec] is 6.5 [μsec] and the pulse interval T2 [μsec] is 12.0 [μsec]. In the case of a medium drop waveform, GND [V] is 0.0 V, DC voltage HV1 [V] is 18.0 [V], DC voltage HV2 [V] is 22.0 [V], and pulse width T1 [μsec. ] Is 6.5 [μsec], the pulse interval T2 [μsec] is 3.0 [μsec], and the pulse width T3 [μsec] is 2.5 [μsec]. Has been. Further, in the case of a droplet waveform, GND [V] is 0.0 V, DC voltage HV1 [V] is 18.0 [V], DC voltage HV2 [V] is 22.0 [V], and pulse width T1 [μsec]. ] Is 6.5 [μsec], the pulse interval T2 [μsec] is 1.5 [μsec], and the pulse width T3 [μsec] is 4.0 [μsec]. Has been.

  As shown in FIG. 28, the horizontal axis is the nozzle number of the nozzle 302 (see FIG. 3), and the vertical axis is the drop volume [pl] of a large droplet whose target value is 10 [pl]. 18 and FIG. 19) shows the variation in the case of a large drop volume [pl] having a target value of 10 [pl]. The droplet volume for each nozzle 302 (see FIG. 3) is obtained by measuring the diameter of a dot printed on a recording sheet as a recording medium and converting the result. Also, due to manufacturing problems, variations tend to occur in the form shown by the solid line 2810.

  As shown in FIG. 29, as in FIG. 28, the horizontal axis is the nozzle number of the nozzle 302 (see FIG. 3), and the vertical axis is the drop volume [pl] of a large droplet whose target value is 10 [pl]. In one stack 1840 (see FIG. 18 and FIG. 19), there is shown a variation in the case of a large drop volume [pl] having a target value of 10 [pl].

  In FIG. 29, the droplet volume of the large droplet after correcting the dispersion of the droplet volume [pl] of the large droplet before correction shown in FIG. 28 based on the classification and correction amount of the 7 rank correction data in FIG. The variation of [pl] is shown. The method for correcting the drop volume [pl] of the large droplet before correction is determined in a certain manner within the classified range by classifying the amount of the drop volume [pl] of the large drop before correction into 7 ranks. Correction is made by adding and subtracting the amount (see FIG. 30).

  As shown in FIG. 30, the classification and correction amount of 7 ranks of correction data are determined, and the variation in the case of a large drop volume [pl] with a target value of 10 [pl] in FIG. 29 is shown in FIG. Correct as follows.

  Specifically, in the first drop large drop waveform 1, if the drop volume VOL [pl] before correction is less than 8.3 [pl], 2.05 [pl] is added and the drop volume of the large drop [ pl] is corrected. In the second large drop waveform 2, if the drop volume VOL [pl] before correction is 8.3 [pl] or more and less than 9.0 [pl], 1.35 [pl] is added. Correct the drop volume [pl] of the large drop. Furthermore, in the third rank large droplet waveform 3, if the droplet volume VOL [pl] before correction is 9.0 [pl] or more and less than 9.7 [pl], 0.65 [pl] is added. Correct the drop volume [pl] of the large drop. Also, in the fourth drop large drop waveform 4, if the drop volume VOL [pl] before correction is 9.7 [pl] or more and less than 10.4 [pl], 0.05 [pl] is subtracted. Correct the drop volume [pl] of the large drop. Furthermore, in the fifth rank large droplet waveform 5, if the droplet volume VOL [pl] before correction is 10.4 [pl] or more and less than 11.1 [pl], 0.75 [pl] is subtracted. Correct the drop volume [pl] of the large drop. In the sixth rank large droplet waveform 6, if the droplet volume VOL [pl] before correction is 11.1 [pl] or more and less than 11.8 [pl], 1.45 [pl] is subtracted. Correct the drop volume [pl] of the large drop. Further, in the large droplet waveform 7 of the seventh rank, if the droplet volume VOL [pl] before correction is 11.8 [pl] or more, 2.15 [pl] is subtracted and the droplet volume [pl] of the large droplet is subtracted. Correct.

  Therefore, by changing the number of driving waveform patterns of each droplet type (large droplet, medium droplet, and small droplet) according to the printing mode, Optimizing the distribution to droplet types according to the print mode, the most effective correction for improving image quality.

  Also, in the high image quality mode, by increasing the number of drive waveform patterns for droplet types with a smaller droplet volume, streaks and unevenness in halftone using small droplets are less noticeable in high image quality printing such as photographs. Make fine corrections. Since large droplets are used in the high density portion, streaks and unevenness are not conspicuous and fine correction is unnecessary.

  Furthermore, in the draft mode, by increasing the number of drive waveform patterns for drop types with a large drop volume, printing speed is emphasized in draft printing of text or graphs, and many large drops are used. Set the value lower. Therefore, since the dispersion of large droplets greatly affects the image quality, fine correction is performed, and small droplets are not used frequently because they are not frequently used.

  The correction data for each drop type is uniquely determined based on the correction data with the largest number of drive waveform patterns, so the variation direction between the drop types is highly correlated. There are many cases. If the direction of variation between each drop type is often highly correlated, it is possible to reduce the amount of correction data by applying correction data for a given drop type to other drop types. At that time, other droplet types cannot be uniquely determined unless correction data having the largest number of waveform data is used as a reference.

  When manufacturing the droplet discharge head 211 (see FIGS. 1 and 2), a test chart for only one predetermined type of droplet is printed, and each nozzle 302 for only one predetermined type of droplet (see FIG. 3). ) Correction data. Then, the data is stored in the droplet discharge head 211 (see FIGS. 1 and 2) or the SWIC 1820 (see FIG. 20) and used for correcting other droplet types, thereby shortening the production process of correction data at the time of manufacture. . The drive waveform pattern applied to the actuator 307 (see FIG. 3) is a digital waveform (standard analog waveform) created by controlling a plurality of switching elements corresponding to a plurality of voltage levels. Multiple voltage levels in the waveform are the same. Since only the time-direction parameters (for example, pulse width, pulse interval, pulse timing, etc.) have different waveforms, the correction can be realized with the SWIC 1820 (see FIG. 20) that can be easily corrected.

  Furthermore, by changing one or more of the voltage level, waveform data, and correction data according to the temperature of the droplet discharge head 211 (see FIGS. 1 and 2), the droplet discharge head 211 ( Since the drop volume changes depending on the temperature shown in FIGS. 1 and 2, the correction is made according to the temperature change.

FIG. 2 is a configuration diagram of a schematic configuration of an image forming apparatus that uses the droplet discharge head driving device according to the first embodiment of the present invention, and a functional block diagram showing an operation of a droplet ejector control program. 1 is a perspective view schematically showing a droplet discharge head according to a first embodiment of the present invention, and a front view of a droplet discharge surface of a droplet discharge head unit constituting the droplet discharge head. 1 is a schematic cross-sectional view illustrating a configuration of a droplet ejector according to a first embodiment of the present invention. It is a block diagram of the 1st drive device for driving the droplet discharge head provided with the several droplet ejector which concerns on 1st Embodiment of this invention. It is a block diagram of the 2nd drive device which is a modification of the 1st drive device for driving the droplet discharge head provided with the several droplet ejector which concerns on 1st Embodiment of this invention. FIG. 5 is a first flowchart relating to main control according to the first embodiment of the present invention, and a second flowchart showing an example of control of a drive waveform generation circuit and SWIC within one printing period focusing on one nozzle. . It is a 1st example of the drive waveform applied to an actuator by the 1st drive device concerning a 1st embodiment of the invention in this application. It is a 2nd example of the drive waveform applied to an actuator by the 1st drive device concerning a 1st embodiment of the invention in this application. It is a 3rd example of the drive waveform applied to an actuator by the 2nd drive device which concerns on 1st Embodiment of this invention. It is a 4th example of the drive waveform applied to an actuator by the 2nd drive concerning a 1st embodiment of the invention in this application. It is a block diagram of the 3rd drive device for driving the droplet discharge head provided with the several droplet ejector which concerns on 2nd Embodiment of this invention. It is a circuit block diagram of a waveform selection circuit according to a second embodiment of the present invention. It is a 5th example of the drive waveform applied to an actuator by the 3rd drive concerning a 2nd embodiment of the invention in this application. It is a 6th example of the drive waveform applied to an actuator by the 3rd drive concerning a 2nd embodiment of the invention in this application. The relationship between the latch signal, the data signal, and the applied waveform is shown by the third drive device according to the second embodiment of the present invention. The first driving device and the second driving device according to the first embodiment of the present invention, and the ejection pulses and the non-ejection pulses applied to the actuator by the first driving device according to the second embodiment. It is a seventh example. Drive waveform 1 and drive waveform in the printing cycle of the actuator by the first drive device and the second drive device according to the first embodiment of the present invention and the first drive device according to the second embodiment. 2 and an example of the driving waveform 3 are shown. 4 shows a droplet discharge head according to a third embodiment of the present invention. FIG. 6 is a layout view of a droplet discharge head according to a third embodiment of the present invention. The structure of SWIC which concerns on the 3rd Embodiment of this invention is shown. An example of a preliminary waveform, an example of a large droplet waveform, an example of a medium droplet waveform, and an example of a small enemy waveform according to the third embodiment of the present invention are shown. Distribution of 16 types of drive waveform patterns in the prior art, distribution of 16 types of drive waveform patterns in the high image quality mode according to the third embodiment of the present invention, and draft mode according to the third embodiment of the present invention 16 shows the distribution of 16 types of drive waveform patterns. The correction data for every nozzle which concerns on 3rd Embodiment of this invention are shown. The relationship (large drop, medium drop, and small drop) between DC voltage HV1 [V] and drop volume [pl] concerning a 3rd embodiment of the invention of this application is shown. The relationship (large droplet) with pulse width T1 [microseconds] and droplet volume [pl] which concerns on 3rd Embodiment of this invention is shown. 10 shows a relationship (medium droplet and small droplet) between a pulse interval T2 [μsec] and a droplet volume [pl] according to a third embodiment of the present invention. 10 shows waveform parameters (design values) of drive waveform patterns (large droplet waveform, medium droplet waveform, and small droplet waveform) by each droplet according to the third embodiment of the present invention. The dispersion | variation in the drop volume before correction | amendment which concerns on 3rd Embodiment of this invention is shown. The variation of the droplet volume after correction | amendment which concerns on 3rd Embodiment of this invention is shown. The correction data classification and correction amount according to the third embodiment of the present invention are shown.

Explanation of symbols

120 Image forming apparatus (drive device, drive program)
160 Image forming unit (drive device, drive program)
211, 1800, 1900 Droplet discharge head (droplet discharge head)
224 Droplet ejector (droplet ejector)
302 nozzle (droplet discharge unit)
304 Pressure chamber (pressure chamber)
307 Actuator (Piezoelectric element)
400 First drive device (Droplet discharge head drive device, Droplet discharge head drive program)
433, 533 Drive waveform generation circuit (drive waveform generation means)
434, 534, 1134, 1820 SWIC (drive waveform selection means, print execution control means)
436, 536, 1136 Waveform selection circuit (drive waveform selection means)
437, 537, 1137 switch (print execution control means)
500 Second Drive Device (Droplet Discharge Head Drive Device, Droplet Discharge Head Drive Program)
1100 Third drive unit (Droplet discharge head drive unit, Droplet discharge head drive program)
1133 Variable power supply (drive waveform generating means)
2040, 2044 (1), ..., 2044 (16) Shift register (drive waveform generating means)
2042 Latch (drive waveform generating means)
2046 (1),..., 2046 (n) selector (drive waveform pattern setting means, mode distribution means, distribution ratio change means)
2048 (1),..., 2048 (n) level shifter (drive waveform pattern setting means, mode distribution means, distribution ratio change means)
2050 (1),..., 2050 (n) Drive waveform generation circuit (print execution means)

Claims (6)

A pressure chamber to which droplets are supplied; a piezoelectric element that changes the pressure in the pressure chamber based on a predetermined drive waveform; and a pressure change that is greater than or equal to a predetermined value in the pressure chamber in communication with the pressure chamber space A droplet discharge head that discharges the droplets, and a droplet discharge head in which a plurality of droplet ejectors are arranged,
A drive waveform generating means for generating a discharge pulse that is a drive waveform for discharging and printing the droplet, and a non-discharge pulse that is a drive waveform for performing at least reverberation suppression without discharging the droplet;
Print execution control means for executing printing based on one or a combination of the ejection pulse and the non-ejection pulse;
When the printing is executed by the printing execution control means, the non-ejection pulse is added at the predetermined printing if the ejection pulse is not output at the time of the next printing at the predetermined printing with the predetermined printing time as a reference. Drive waveform selection means for selecting a combination of the drive waveforms so as not to
A liquid droplet ejection head drive device comprising:   When the drive waveform selection means outputs the ejection pulse at the time of the next printing after the predetermined printing, the combination of the driving waveforms is selected so that the non-ejection pulse is added at the time of the predetermined printing. 2. The droplet ejection head driving apparatus according to claim 1, wherein:   When the drive waveform selection means outputs the ejection pulse at the predetermined printing time and the next printing time, the drive waveform selection means adds the non-ejection pulse in addition to the ejection pulse at the predetermined printing time. 2. The droplet discharge head driving apparatus according to claim 1, wherein a combination is selected. A pressure chamber to which droplets are supplied; a piezoelectric element that changes the pressure in the pressure chamber based on a predetermined drive waveform; and a pressure change that is greater than or equal to a predetermined value in the pressure chamber in communication with the pressure chamber space In a droplet discharge head drive program in which a plurality of droplet ejectors each including a droplet discharge unit that discharges the droplets are arranged,
Generating a discharge pulse that is a drive waveform for discharging and printing the droplets, and a non-discharge pulse that is a drive waveform for suppressing at least reverberation without discharging the droplets;
Printing is performed based on one or a combination of the ejection pulse and the non-ejection pulse,
When performing the printing, the drive is performed so that the non-ejection pulse is not added during the predetermined printing when the ejection pulse is not output at the time of the next printing after the predetermined printing with reference to the predetermined printing time. Selecting a combination of waveforms
A droplet discharge head drive program executed by a computer. A pressure chamber to which droplets are supplied; a piezoelectric element that changes the pressure in the pressure chamber based on a predetermined drive waveform; and a pressure change that is greater than or equal to a predetermined value in the pressure chamber in communication with the pressure chamber space A droplet discharge head that discharges the droplets, and a droplet discharge head in which a plurality of droplet ejectors are arranged,
Print execution means for generating a drive waveform of a predetermined pattern for the droplet discharge head and executing printing;
Drive waveform pattern setting means for setting a predetermined number of drive waveform patterns based on sorting requirements including the droplet volume of the droplets;
A mode distribution means for distributing the drive waveform pattern to a plurality of print droplet modes and a non-print droplet mode;
Drive waveform generating means for generating a drive waveform by selecting from the drive waveform pattern set by the drive waveform pattern setting means based on a print condition including an image specified at the time of printing;
A distribution ratio changing means for changing the distribution ratio based on a mode specified at the time of printing when the drive waveform pattern is distributed by the mode distribution means;
A liquid droplet ejection head drive device comprising: A pressure chamber to which droplets are supplied; a piezoelectric element that changes the pressure in the pressure chamber based on a predetermined drive waveform; and a pressure change that is greater than or equal to a predetermined value in the pressure chamber in communication with the pressure chamber space With respect to a droplet discharge head in which a plurality of droplet ejectors provided with a droplet discharge portion that discharges the droplets are arranged,
When generating a drive waveform of a predetermined pattern for the droplet discharge head and executing printing,
Based on the sorting requirements including the droplet volume of the droplet, set a limited number of driving waveform patterns in advance,
When allocating the drive waveform pattern to a plurality of printing droplet modes, as well as one non-printing droplet mode,
Change the distribution ratio based on the printing conditions including the image specified when printing,
Based on printing conditions including an image designated at the time of printing, generating a driving waveform by selecting from a driving waveform pattern in which a limited number is set in advance,
A droplet discharge head drive program executed by a computer.

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