JP2013111836A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem wherein an increase in power consumption cannot be controlled by a simple constitution or a simple control when a fine driving pulse is included in a common drive waveform.SOLUTION: The first drive waveform Pv1 including a plurality of discharge pulse P1-P3 for discharging drips of different sizes and the non-discharge pulse P0 for flowing the liquid in a nozzle without discharging the drips, and the second drive waveform Pv2 including a plurality of discharge pulses P1-P3 for discharging the drips of different sizes, and not including the non-discharge pulse P0 for flowing the liquid in the nozzle while not discharging the drips, are generated and output. The first drive waveform Pv1 and the second drive waveform Pv2 have the same wavelength, and the first drive waveform Pv1 is generated and output in the drive period for oscillating the nozzle meniscus.

Description

  The present invention relates to an image forming apparatus.

  As an image forming apparatus such as a printer, a facsimile machine, a copying machine, a plotter, and a complex machine of these, for example, an ink jet recording apparatus is known as a liquid discharge recording type image forming apparatus using a liquid discharge head for discharging droplets as a recording head. It has been.

  In such an image forming apparatus, for example, a plurality of driving pulses (ejection pulses) for ejecting droplets within one driving cycle are generated in time series and output as a common driving waveform. When forming two or more drive pulses, a plurality of droplets are ejected, and a plurality of droplets are combined and landed during flight, thereby forming dots of a plurality of sizes. It is known that the drive waveform includes a non-ejection pulse that drives the head without droplet ejection, and similarly, by performing fine driving by selecting the non-ejection pulse, stable droplet ejection is performed. Yes.

  Then, during one drive signal generation cycle, the drive signal includes a first unit cycle signal composed of a fine vibration pulse and a discharge pulse generated after the fine vibration pulse, and a second unit having no discharge pulse and only a discharge pulse. A drive signal including a unit periodic signal is generated and output, and the type and generation order of the ejection pulses included in the first unit periodic signal are the same as the type and generation order of the ejection pulses included in the second unit periodic signal. It is known that the drive signal has at least one second unit periodic signal at the head portion, and the generation period of the second unit periodic signal is shorter than the generation period of the first unit periodic signal (patent) Reference 1).

  Also, a first drive waveform generating means for generating a common drive waveform for discharge including a plurality of discharge waveform elements for discharging a plurality of types of droplets having different volumes, and a fine vibration waveform for finely vibrating the meniscus A nozzle that includes a second drive waveform generating unit that generates a common drive waveform for micro vibration including elements independently, and that applies a discharge waveform element to a pressure generating element of a nozzle that discharges liquid, but does not discharge liquid Among these pressure generating elements, there is also known one having a drive selection means for selectively applying a micro-vibration waveform element (Patent Document 2).

Japanese Patent No. 4623101 JP 2006-035568 A

  However, as disclosed in Patent Document 1, if the waveform lengths of the first and second unit periodic signals included in the drive signal are different, the drive period changes, and the drive control of the head is complicated. There is a problem of becoming. In addition, as disclosed in Patent Document 2, there is a problem that the configuration becomes complicated if two drive waveform generation units are provided.

  The present invention has been made in view of the above problems, and an object thereof is to suppress an increase in power consumption with a simple configuration.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
A plurality of nozzles for discharging droplets, an individual liquid chamber that communicates with the nozzles, a common liquid chamber that supplies liquid to the plurality of individual liquid chambers, and a pressure generator that generates pressure to pressurize the liquid in the individual liquid chambers A recording head comprising:
Drive waveform generation means for generating and outputting a drive waveform including a plurality of drive pulses applied to the pressure generation means of the recording head in a time series within one drive cycle;
Means for selecting one or more required drive pulses from among a plurality of drive pulses included in the drive waveform output from the drive waveform generating means and supplying the selected one to the pressure generating means of the recording head. And
The drive waveform generation means includes
A first drive waveform including a plurality of ejection pulses for ejecting droplets having different sizes and a non-ejection pulse for causing the liquid in the nozzle to flow without ejecting the droplets;
Generating and outputting a second drive waveform including a plurality of ejection pulses for ejecting droplets of different sizes and not including a non-ejection pulse for causing the liquid in the nozzle to flow without ejecting the droplets;
The first drive waveform and the second drive waveform have the same waveform length,
The first driving waveform is generated and output in a driving cycle in which the nozzle meniscus is vibrated.

  According to the present invention, it is possible to suppress an increase in consumption electrodes with a simple configuration.

1 is a schematic side view illustrating an overall configuration of a mechanism unit of an image forming apparatus according to the present invention. It is principal part plane explanatory drawing of the mechanism part. FIG. 4 is a cross-sectional explanatory view in the longitudinal direction of the liquid chamber showing an example of a liquid discharge head constituting the recording head of the image forming apparatus. It is sectional explanatory drawing similarly used for description of droplet discharge operation | movement. FIG. 2 is a block explanatory diagram illustrating an overview of a control unit of the image forming apparatus. FIG. 3 is a block explanatory diagram illustrating an example of a print control unit and a head driver of the control unit. It is explanatory drawing explaining the 1st drive waveform and 2nd drive waveform in 1st Embodiment of this invention. It is explanatory drawing explaining an example of the common drive waveform in the embodiment. It is explanatory drawing explaining an example of the common drive waveform in 2nd Embodiment of this invention. It is explanatory drawing explaining an example of the common drive waveform in 3rd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an example of an image forming apparatus according to the present invention will be described with reference to FIGS. FIG. 1 is an explanatory side view for explaining the overall configuration of the image forming apparatus, and FIG. 2 is an explanatory plan view of a main part of the apparatus.

  This image forming apparatus is a serial type ink jet recording apparatus, and a carriage 33 is slidable in a main scanning direction by main and sub guide rods 31 and 32 which are guide members horizontally mounted on the left and right side plates 21A and 21B of the apparatus main body 1. It is held and moved and scanned in the direction indicated by the arrow (carriage main scanning direction) in FIG. 2 via a timing belt by a main scanning motor (not shown).

  The carriage 33 is provided with recording heads 34a and 34b composed of liquid ejection heads for ejecting ink droplets of yellow (Y), cyan (C), magenta (M), and black (K). The “recording head 34” is arranged in a sub-scanning direction orthogonal to the main scanning direction, and the ink droplet ejection direction is directed downward.

  Each of the recording heads 34 has two nozzle rows. One nozzle row of the recording head 34a has black (K) droplets, the other nozzle row has cyan (C) droplets, and the recording head 34b has one nozzle row. One nozzle row ejects magenta (M) droplets, and the other nozzle row ejects yellow (Y) droplets. As the recording head 34, a recording head having a nozzle row of each color in which a plurality of nozzles are arranged on one nozzle surface can be used.

  The carriage 33 has head tanks 35a and 35b as second ink supply units for supplying ink of each color corresponding to the nozzle rows of the recording head 34 (referred to as “head tank 35” when not distinguished). It is equipped with. From the ink cartridges (main tanks) 10y, 10m, 10c, and 10k of the respective colors that are detachably attached to the cartridge loading unit 4 to the head tank 35, the respective colors are supplied by the supply pump unit 24 through the supply tubes 36 of the respective colors. The recording liquid is replenished.

  On the other hand, as a paper feeding unit for feeding the papers 42 stacked on the paper stacking unit (pressure plate) 41 of the paper feeding tray 2, a half-moon roller (feeding) that separates and feeds the papers 42 one by one from the paper stacking unit 41. A separation pad 44 made of a material having a large friction coefficient is provided facing the paper roller 43) and the paper feed roller 43, and the separation pad 44 is urged toward the paper feed roller 43 side.

  In order to feed the paper 42 fed from the paper feeding unit to the lower side of the recording head 34, a guide member 45 for guiding the paper 42, a counter roller 46, a transport guide member 47, and a tip pressure roller. And a holding belt 48 which is a conveying means for electrostatically attracting the fed paper 42 and conveying it at a position facing the recording head 34.

  The transport belt 51 is an endless belt, and is configured to wrap around the transport roller 52 and the tension roller 53 and circulate in the belt transport direction (sub-scanning direction). Further, a charging roller 56 that is a charging unit for charging the surface of the transport belt 51 is provided. The charging roller 56 is disposed so as to come into contact with the surface layer of the transport belt 51 and to rotate following the rotation of the transport belt 51. The transport belt 51 rotates in the belt transport direction of FIG. 2 when the transport roller 52 is rotationally driven through timing by a sub-scanning motor (not shown).

  Further, as a paper discharge unit for discharging the paper 42 recorded by the recording head 34, a separation claw 61 for separating the paper 42 from the conveying belt 51, a paper discharge roller 62, and a spur 63 that is a paper discharge roller. And a paper discharge tray 3 below the paper discharge roller 62.

  A duplex unit 71 is detachably mounted on the back surface of the apparatus body 1. The duplex unit 71 takes in the paper 42 returned by the reverse rotation of the conveyance belt 51, reverses it, and feeds it again between the counter roller 46 and the conveyance belt 51. The upper surface of the duplex unit 71 is a manual feed tray 72.

  Further, a maintenance / recovery mechanism 81 for maintaining and recovering the nozzle state of the recording head 34 is disposed in the non-printing area on one side of the carriage 33 in the scanning direction. The maintenance / recovery mechanism 81 includes cap members (hereinafter referred to as “caps”) 82a and 82b (hereinafter referred to as “caps 82” when not distinguished from each other) for capping the nozzle surfaces of the recording head 34, and nozzle surfaces. A wiper member (wiper blade) 83 for wiping the recording medium, an empty discharge receiver 84 for receiving liquid droplets when performing empty discharge for discharging liquid droplets that do not contribute to recording in order to discharge the thickened recording liquid, and a carriage And a carriage lock 87 for locking 33. Further, a waste liquid tank 99 for storing waste liquid generated by the maintenance and recovery operation is mounted on the lower side of the head maintenance and recovery mechanism 81 in a replaceable manner with respect to the apparatus main body.

  Further, in the non-printing area on the other side of the carriage 33 in the scanning direction, there is an empty space for receiving liquid droplets when performing empty discharge for discharging liquid droplets that do not contribute to recording in order to discharge the recording liquid thickened during recording or the like. A discharge receiver 88 is disposed, and the idle discharge receiver 88 includes an opening 89 along the nozzle row direction of the recording head 34.

  In this image forming apparatus configured as described above, the sheets 42 are separated and fed one by one from the sheet feed tray 2, and the sheet 42 fed substantially vertically upward is guided by the guide 45, and includes the transport belt 51 and the counter. It is sandwiched between the rollers 46 and conveyed, and the leading end is guided by the conveying guide 37 and pressed against the conveying belt 51 by the leading end pressing roller 49, and the conveying direction is changed by approximately 90 °.

  At this time, a voltage is applied to the charging roller 56 so that a positive output and a negative output are alternately repeated, and the conveying belt 51 is charged with an alternating charging voltage pattern, and the sheet 42 is placed on the charged conveying belt 51. When fed, the paper 42 is attracted to the transport belt 51, and the paper 42 is transported in the sub-scanning direction by the circular movement of the transport belt 51.

  Therefore, by driving the recording head 34 according to the image signal while moving the carriage 33, ink droplets are ejected onto the stopped paper 42 to record one line, and after the paper 42 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 42 has reached the recording area, the recording operation is finished and the paper 42 is discharged onto the paper discharge tray 3.

  When performing the maintenance and recovery of the nozzles of the recording head 34, the nozzle 33 performs the suction from the nozzles by moving the carriage 33 to a position facing the maintenance and recovery mechanism 81 which is the home position and performing capping by the cap member 82. By performing a maintenance and recovery operation such as an empty discharge operation for discharging droplets that do not contribute to image formation, it is possible to perform image formation by stable droplet discharge.

  Next, an example of the liquid discharge head constituting the recording head 34 will be described with reference to FIGS. 3 and 4 are cross-sectional explanatory views along the liquid chamber longitudinal direction (direction orthogonal to the nozzle arrangement direction) of the head.

  This liquid discharge head is composed of an individual liquid chamber (a pressure chamber, a pressure chamber, and a nozzle plate 104 that joins a flow path plate 101, a vibration plate member 102, and a nozzle plate 103 to discharge a droplet 104 through a through hole 105. It means to include what is called a pressurized liquid chamber, a pressure chamber, an individual flow path, a pressure generation chamber, etc. Hereinafter, simply referred to as “liquid chamber”) 106, a fluid resistance portion for supplying liquid to the liquid chamber 106 107 and the liquid introduction part 108 are formed, respectively, and liquid (ink) is introduced into the liquid introduction part 108 from the common liquid chamber 110 formed in the frame member 117 through the filter 109 formed in the vibration plate member 102. Ink is supplied from the unit 108 to the liquid chamber 106 through the fluid resistance unit 107.

  The flow path plate 101 is formed by laminating metal plates such as SUS to form openings and groove portions such as the through hole 105, the liquid chamber 106, the fluid resistance portion 107, and the liquid introduction portion 108. The diaphragm member 102 is a wall surface member that forms the wall surface of each liquid chamber 106, fluid resistance portion 107, liquid introduction portion 108, and the like, and a member that forms the filter portion 109. The flow path plate 101 is not limited to a metal plate such as SUS, and may be formed by anisotropic etching of a silicon substrate.

  Then, a columnar shape as a drive element (actuator means, pressure generating means) that generates energy for pressurizing the ink in the liquid chamber 106 to the surface opposite to the liquid chamber 106 of the vibration plate member 102 and ejecting droplets from the nozzle 104. A laminated piezoelectric member 112 which is an electromechanical conversion element is joined. One end of the piezoelectric member 112 is joined to the base member 113, and the FPC 115 that transmits a driving waveform is connected to the piezoelectric member 112. These elements constitute the piezoelectric actuator 111.

  In this example, the piezoelectric member 112 is used in the d33 mode that expands and contracts in the stacking direction, but it may be in the d31 mode that expands and contracts in the direction orthogonal to the stacking direction.

  In the liquid discharge head configured as described above, for example, as shown in FIG. 3, the piezoelectric member 112 contracts and the diaphragm member 102 deforms by lowering the voltage applied to the piezoelectric member 112 from the reference potential Ve. As the volume of the liquid chamber 106 expands, ink flows into the liquid chamber 106, and then, as shown in FIG. 4, the voltage applied to the piezoelectric member 112 is increased to extend the piezoelectric member 112 in the stacking direction. By deforming the vibration plate member 102 in the direction of the nozzle 104 and contracting the volume of the liquid chamber 106, the ink in the liquid chamber 106 is pressurized, and the droplets 301 are ejected from the nozzle 104.

  Then, by returning the voltage applied to the piezoelectric member 112 to the reference potential Ve, the diaphragm member 102 is restored to the initial position, and the liquid chamber 106 expands to generate a negative pressure. The liquid chamber 106 is filled with ink. Therefore, after the vibration of the meniscus surface of the nozzle 104 is attenuated and stabilized, the operation proceeds to the next droplet discharge.

  Next, an outline of the control unit of the image forming apparatus will be described with reference to FIG. FIG. 5 is a block diagram of the control unit.

  The control unit 500 shuts off the power of the apparatus, the CPU 511 that controls the entire apparatus, the ROM 502 that stores fixed data such as various programs including programs executed by the CPU 511, the RAM 503 that temporarily stores image data and the like. A rewritable nonvolatile memory 504 for holding data while it is being processed, an image processing for performing various signal processing and rearrangement on image data, and other input / output signals for controlling the entire apparatus. And.

  Further, a print control unit 508 including a data transfer unit for driving and controlling the recording head 34 and a driving signal generating unit, a head driver (driver IC) 509 for driving the recording head 34 provided on the carriage 33 side, A main scanning motor 554 that moves and scans the carriage 33, a sub-scanning motor 555 that moves the conveyor belt 51 around, a movement of the cap 82 and the wiper member 83 of the maintenance and recovery mechanism 81, and a maintenance and recovery motor 556 that drives the suction pump 812 and the like are driven. For example, a motor drive unit 510 for supplying an AC bias to the charging roller 56, a supply system drive unit 512 for driving the liquid feed pump 241, and the like.

  The control unit 500 is connected to an operation panel 514 for inputting and displaying information necessary for the apparatus.

  The control unit 500 has an I / F 506 for transmitting and receiving data and signals to and from the host side, an information processing device such as a personal computer, an image reading device such as an image scanner, an imaging device such as a digital camera, and the like. From the host 600 side via the cable or network via the I / F 506.

  The CPU 501 of the control unit 500 reads and analyzes the print data in the reception buffer included in the I / F 506, performs necessary image processing, data rearrangement processing, and the like in the ASIC 505, and prints the image data. The data is transferred from the unit 508 to the head driver 509. In order to output an image, dot pattern data can be generated by the printer driver 601 on the host 600 side or by the control unit 500.

  The print control unit 508 transfers the above-described image data as serial data, and outputs a transfer clock, a latch signal, a control signal, and the like necessary for transferring the image data and confirming the transfer to the head driver 509. Including a D / A converter for D / A converting D / A conversion of drive pulse pattern data stored in the ROM, a voltage signal amplifier, a current amplifier, and the like, and a drive signal or a plurality of drive pulses Is output to the head driver 509.

  The head driver 509 selects a driving pulse constituting a driving waveform provided from the print control unit 508 based on image data corresponding to one line of the recording head 34 input serially, and drops droplets of the recording head 34. The recording head 34 is driven by applying it to the piezoelectric member 112 as pressure generating means for generating energy to be discharged. At this time, by selecting part or all of the pulses constituting the drive waveform or all or part of the waveform elements forming the pulses, for example, dots of different sizes such as large drops, medium drops, and small drops Can be sorted out.

  The I / O unit 513 acquires information from various sensor groups 515 mounted on the apparatus, extracts information necessary for controlling the printer, a print control unit 508, a motor drive unit 510, and an AC bias supply unit. Used to control 511. The sensor group 515 includes an optical sensor for detecting the position of the paper, a thermistor for monitoring the temperature in the machine, a sensor for monitoring the voltage of the charging belt, an interlock switch for detecting opening and closing of the cover, and the like. The I / O unit 513 can process various sensor information.

  Next, an example of the print control unit 508 and the head driver 509 will be described with reference to the block explanatory diagram of FIG.

  The print control unit 508 generates a drive waveform (common drive waveform) composed of a plurality of pulses (drive signals) within one print cycle (one drive cycle) during image formation, and outputs a drive waveform generation unit 701. A data transfer unit 702 that outputs 2-bit image data (gradation signals 0 and 1) corresponding to a print image, a clock signal, a latch signal (LAT), and droplet control signals M0 to M3 is provided.

  The droplet control signal is a 2-bit signal that instructs each droplet to open and close an analog switch 715, which will be described later, of the head driver 209. A pulse or waveform to be selected in accordance with the printing cycle of the common drive waveform. The element makes a state transition to the H level (ON), and when not selected, makes a state transition to the L level (OFF).

  The head driver 509 receives a transfer clock (shift clock) from the data transfer unit 702 and serial image data (gradation data: 2 bits / 1 channel (1 nozzle)), and register values of the shift register 711. The latch circuit 712 for latching the signal with the latch signal, the decoder 713 for decoding the gradation data and the droplet control signals M0 to M3 and outputting the result, and the logic level voltage signal of the decoder 713 can operate the analog switch 715. A level shifter 714 that performs level conversion to a level and an analog switch 715 that is turned on / off (opened / closed) by the output of the decoder 713 provided through the level shifter 714 are provided.

  The analog switch 715 is connected to the selection electrode (individual electrode) of each piezoelectric member 112, and the common drive waveform Pv from the drive waveform generation unit 701 is input. Therefore, the analog switch 715 is turned on in accordance with the result of decoding the serially transferred image data (gradation data) and the droplet control signals M0 to M3 by the decoder 713, so that a required pulse constituting the common drive waveform Pv is obtained. (Or a wave element) is passed (selected) and applied to the piezoelectric member 112.

  Next, drive waveforms in the first embodiment of the present invention will be described with reference to FIGS. FIG. 7 is an explanatory diagram for explaining the first drive waveform and the second drive waveform, and FIG. 8 is an explanatory diagram for explaining an example of the common drive waveform Pv in the same embodiment.

  The driving pulse is a term indicating a pulse as an element constituting a driving waveform, and the ejection pulse is a term indicating a driving pulse applied to the pressure generating means to eject a droplet, and a non-ejection pulse (fine driving pulse). ) Is used as a term indicating a pulse which is applied to the pressure generating means but does not eject a droplet (flows ink in the nozzle). Further, the pulse described below is an example, and the present invention is not limited to this.

  In the present embodiment, the drive waveform generation unit 701 generates and outputs, for example, the first drive waveform Pv1 shown in FIG. 7A and the second drive waveform Pv2 shown in FIG. 7B as the common drive waveform Pv.

  The first driving waveform Pv1 includes ejection pulses P1 to P3 for ejecting three types of droplets (large droplets, medium droplets, and small droplets), and non-ejection pulses (fine driving) for causing the liquid (ink) in the nozzle to flow. Pulse) is a drive waveform including P0.

  The second drive waveform Pv2 includes ejection pulses P1 to P3 for ejecting droplets of three sizes (large droplets, medium droplets, and small droplets) having the same waveform as the first drive waveform, and the liquid (ink) in the nozzles. ) Is a drive waveform that does not include the non-ejection pulse (fine drive pulse) P0.

  Here, the waveform length (cycle) T1 of the first drive waveform Pv1 and the waveform length (cycle) T2 of the second drive waveform Pv2 are the same (T1 = T2). Here, each of the waveform lengths T1 and T2 of the first drive waveform Pv1 and the second drive waveform Pv2 is one printing cycle (one drive cycle).

  The drive waveform generation unit 701 generates and outputs the pulses P0 to P4 or P1 to P4 of the first drive waveform Pv1 or the second drive waveform Pv2 in time series in synchronization with the reference signal. The reference signal is a signal output corresponding to the position of the carriage 33 in the main scanning direction according to the density of the image to be formed.

  On the other hand, the data transfer unit 702 outputs droplet control signals M0 to M3 to select the fine driving pulse P0 of the first driving waveform Pv1 or the required pulse of the ejection pulses P1 to P3, or the second driving waveform Pv2. The required pulses of the ejection pulses P1 to P3 are selected.

  In this embodiment, as shown in FIG. 8, the first drive waveform Pv1 and the second drive waveform Pv2 are alternately generated and output as the common drive waveform Pv.

  As a result, in the drive cycle in which the nozzles of the recording head are finely driven, the first drive waveform Pv1 is generated and output and the fine drive pulse P0 is selected, so that the fine drive can be performed.

  In this way, by alternately repeating the first drive waveform Pv1 and the second drive waveform Pv2, it is possible to reduce power consumption as compared with the case of generating and outputting a drive waveform including a fine drive pulse at every drive cycle. .

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 9 is an explanatory diagram illustrating an example of the common drive waveform Pv in the embodiment.

  In the present embodiment, as the common drive waveform Pv, the second drive waveform Pv2 is generated and output in a plurality of drive cycles following the drive cycle in which the first drive waveform Pv1 is generated and output.

  Thereby, the number of generation outputs of the first drive waveform Pv1 including the fine drive pulse is smaller than that in the first embodiment, and the power consumption can be further reduced.

  Note that the number of times of continuous generation and output of the second drive waveform Pv2 can be changed according to the printing environment and printing conditions.

  Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 10 is an explanatory diagram illustrating an example of the common drive waveform Pv in the embodiment.

  In the present embodiment, when the environmental temperature is high, the common driving waveform PvH for high temperature shown in FIG. 10A is used when the environmental temperature is high, and when the environmental temperature is normal temperature, the common driving waveform PvN for normal temperature shown in FIG. When the environmental temperature is low, the low temperature common drive waveform PvL of FIG. 10C is generated and output.

  The environmental temperature is detected by a temperature sensor, and the detected temperature is compared with two predetermined threshold values Th and Tl (Th> Tl). If the detected temperature is equal to or higher than the threshold value Th, the detected temperature is higher than the threshold value Tl. If it is between low temperature and a threshold Th and Tl, it is determined that the temperature is normal.

  Thereby, the viscosity increase in the nozzle can be efficiently suppressed while suppressing power consumption.

  In the present application, the “paper” is not limited to paper, but includes OHP, cloth, glass, a substrate, etc., and means a material to which ink droplets or other liquids can be attached. , Recording media, recording paper, recording paper, and the like. In addition, image formation, recording, printing, printing, and printing are all synonymous.

  The “image forming apparatus” means an apparatus that forms an image by discharging liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc. “Formation” means not only giving an image having a meaning such as a character or a figure to a medium but also giving an image having no meaning such as a pattern to the medium (simply causing a droplet to land on the medium). ) Also means.

  The “ink” is not limited to an ink unless otherwise specified, but includes any liquid that can form an image, such as a recording liquid, a fixing processing liquid, or a liquid. Used generically, for example, includes DNA samples, resists, pattern materials, resins, and the like.

  In addition, the “image” is not limited to a planar image, and includes an image given to a three-dimensionally formed image and an image formed by three-dimensionally modeling a solid itself.

  Further, the image forming apparatus includes both a serial type image forming apparatus and a line type image forming apparatus, unless otherwise limited.

33 Carriage 34, 34a, 34b Recording head (liquid ejection head)
500 Control Unit 508 Print Control Unit 701 Drive Waveform Generation Unit 702 Data Transfer Unit

Claims (4)

A plurality of nozzles for discharging droplets, an individual liquid chamber that communicates with the nozzles, a common liquid chamber that supplies liquid to the plurality of individual liquid chambers, and a pressure generator that generates pressure to pressurize the liquid in the individual liquid chambers A recording head comprising:
Drive waveform generation means for generating and outputting a drive waveform including a plurality of drive pulses applied to the pressure generation means of the recording head in a time series within one drive cycle;
Means for selecting one or more required drive pulses from among a plurality of drive pulses included in the drive waveform output from the drive waveform generating means and supplying the selected one to the pressure generating means of the recording head. And
The drive waveform generation means includes
A first drive waveform including a plurality of ejection pulses for ejecting droplets having different sizes and a non-ejection pulse for causing the liquid in the nozzle to flow without ejecting the droplets;
Generating and outputting a second drive waveform including a plurality of ejection pulses for ejecting droplets of different sizes and not including a non-ejection pulse for causing the liquid in the nozzle to flow without ejecting the droplets;
The first drive waveform and the second drive waveform have the same waveform length,
The image forming apparatus, wherein the first driving waveform is generated and output in a driving cycle in which the nozzle meniscus is vibrated.   The image forming apparatus according to claim 1, wherein the plurality of ejection pulses of the first drive waveform and the plurality of ejection pulses of the second drive waveform are the same waveform.   The second drive waveform is generated and output in at least the next drive cycle of the drive cycle in which the first drive waveform is generated and output, and the first drive waveform is generated in the next drive cycle after the second drive waveform is generated and output. The image forming apparatus according to claim 1, wherein the image forming apparatus outputs the image.   4. The image according to claim 3, wherein the number of drive cycles for generating and outputting the second drive waveform during a drive cycle for generating and outputting the first drive waveform is changed according to an ambient temperature of the recording head. 5. Forming equipment.

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