JP6922314B2 - Drive waveform generator, liquid discharge device - Google Patents

Description

The present invention relates to a drive waveform generator and a device for discharging a liquid.

In the liquid discharge head, when the droplets are discharged from the target nozzle due to the high density of the nozzles, the discharge speed of the liquid discharged from the target nozzle fluctuates depending on the discharge state of the nozzle adjacent to the target nozzle. Cross talk occurs, and the landing position is likely to shift.

Conventionally, it is known that the voltage applied to the pressure generating means corresponding to the target nozzle is changed according to whether or not the nozzle adjacent to the target nozzle ejects droplets (Patent Document 1).

Japanese Unexamined Patent Publication No. 60-008075

However, there is a problem that the configuration in which the drive voltage of the target nozzle is simply changed depending on the presence or absence of ejection of the adjacent nozzle cannot cope with the change in the size of the droplet ejected from the adjacent nozzle.

The present invention has been made in view of the above problems, and an object of the present invention is to suppress fluctuations in the discharge rate of a liquid.

In order to solve the above problems, the drive waveform generator according to the present invention
A device that generates and outputs a drive waveform to discharge liquid from the liquid discharge head.
A means for generating the drive waveform is provided for each of the plurality of pressure generating means corresponding to the plurality of nozzles of the liquid discharge head.
The means for generating is
A means for detecting information correlating with the type of the driving waveform given to the pressure generating means corresponding to a nozzle adjacent to the target nozzle and changing the waveform shape of the driving waveform given to the target nozzle according to the detected information. equipped with a,
The information that correlates with the type of the drive waveform is the information on the type of droplets ejected from the nozzle.
When the type of droplets ejected from the adjacent nozzles increases the droplet velocities ejected from the target nozzle, the droplet velocities ejected from the target nozzles decrease.
When the type of droplets ejected from the adjacent nozzles decreases the droplet velocities ejected from the target nozzle, the droplet velocities ejected from the target nozzles are increased.
As described above, the waveform shape of the drive waveform given to the target nozzle is changed .

According to the present invention, fluctuations in the discharge rate of the liquid can be suppressed.

It is a plane explanatory view of the mechanism part of an example of the apparatus which discharges a liquid which concerns on this invention. Similarly, it is a side view of the main part. It is sectional drawing in the direction orthogonal to the nozzle arrangement direction (the liquid chamber longitudinal direction) of an example of a liquid discharge head. Similarly, it is a cross-sectional explanatory view of the nozzle arrangement direction (the liquid chamber short side direction). It is a block explanatory drawing of the control part of this apparatus. It is a block explanatory drawing of an example of a head driver. It is explanatory drawing of an example of a discharge drive waveform generated by a drive waveform generator. It is explanatory drawing which shows an example of the relationship between the drop type discharged from the adjacent nozzle adjacent to the target nozzle and the discharge speed of the target nozzle, which is used for the explanation of the adjacent crosstalk. It is a schematic explanatory drawing used for the explanation of the driving condition of FIG. It is explanatory drawing of an example of the correction value table used in the generation of the drive waveform in 1st Embodiment of this invention. It is explanatory drawing which provides the explanation of the specific example of the correction of the discharge drive waveform for each nozzle using the correction value table.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. An example of the device for discharging the liquid according to the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan explanatory view of a mechanical portion of the device, and FIG. 2 is a side explanatory view of a main part.

This device is a serial type device, and the carriage 3 is movably held in the main scanning direction by a guide mechanism such as the main guide member 1. The carriage 3 is reciprocated in the main scanning direction (carriage moving direction) via a timing belt 8 bridged between the driving pulley 6 and the driven pulley 7 by the main scanning motor 5 constituting the main scanning moving mechanism.

The carriage 3 is equipped with two liquid discharge units 40A and 40B (when not distinguished, they are referred to as "liquid discharge unit 40"; the same applies to other members). The liquid discharge unit 40 is configured by integrating a liquid discharge head 41 as a liquid discharge means and a head driver (drive waveform generator) 509 (see FIG. 5).

The liquid discharge head 41 has two nozzle rows in which a plurality of nozzles are arranged. One nozzle row of the head 41A of the liquid discharge unit 40A ejects black (K) droplets, and the other nozzle row ejects cyan (C) droplets. Further, one nozzle row of the head 41B of the liquid discharge unit 40B ejects magenta (M) droplets, and the other nozzle row ejects yellow (Y) droplets.

As the liquid ejection means, one having a plurality of nozzle rows for ejecting droplets of each color in which a plurality of nozzles are arranged on the nozzle surface of one liquid ejection head can also be used.

The head tank 42 is configured to include a plurality of tank portions in which two tank portions for accommodating liquids of each color are paired, corresponding to two nozzle rows of each head 41.

A cartridge holder 51 is arranged on the main body side of the apparatus to replace the main tank (liquid cartridge) 50 (50y, 50m, 50c, 50k) containing the liquids of each color.

The cartridge holder 51 is provided with a liquid feed pump section 52, and each color is connected to the tank section of each head tank 42 from the main tank 50 via a supply tube (also referred to as a liquid supply path) 56 of each color by the liquid feed pump section 52. Liquid is supplied.

On the other hand, in order to convey the sheet material 10, the transfer belt 12 is provided as a transfer means for adsorbing the sheet material 10 and transporting the sheet material 10 at a position facing the head 41 of the liquid discharge unit 40. The adsorption of the sheet material 10 by the transport belt 12 can be performed by electrostatic adsorption or air adsorption.

The transport belt 12 is an endless belt and is hung between the transport roller 13 and the tension roller 14. Then, the transport belt 12 orbits in the sub-scanning direction by rotationally driving the transport roller 13 via the timing belt 17 and the timing pulley 18 by the sub-scanning motor 16.

Further, on one side of the carriage 3 in the main scanning direction, a maintenance / recovery mechanism 20 for maintaining / recovering the head 41 is arranged on the side of the transport belt 12. On the other side of the carriage 3 in the main scanning direction, an empty discharge receiver 81 for receiving the liquid pre-discharged (empty discharged) from the head 41 is arranged on the side of the transport belt 12.

The maintenance / recovery mechanism 20 is composed of, for example, a suction cap 21 that caps the nozzle surface 41a of the head 41, a moisturizing cap 22, a wiper member 23 that wipes the nozzle surface 41a, an empty discharge receiver 24 that receives an empty discharge liquid, and the like. There is. It should be noted that the empty discharge may be performed on the suction cap 21.

Further, an encoder scale 123 forming a predetermined pattern is stretched between both side plates along the main scanning direction of the carriage 3, and an encoder sensor 124 composed of a transmissive photo sensor that reads the pattern of the encoder scale 123 is attached to the carriage 3. It is provided. These encoder scales 123 and encoder sensors 124 constitute a linear encoder (main scanning encoder) that detects the movement of the carriage 3.

A chord wheel 125 is attached to the shaft of the transport roller 13, and an encoder sensor 126 composed of a transmissive photo sensor that detects a pattern formed on the chord wheel 125 is provided. These code wheels 125 and an encoder sensor 126 constitute a rotary encoder (sub-scanning encoder) that detects the movement amount and movement position of the transfer belt 12.

In the device configured in this way, the sheet material 10 is fed onto the transport belt 12 and sucked, and is transported in the sub-scanning direction by the orbital movement of the transport belt 12.

Therefore, by driving the head 41 in response to the image signal while moving the carriage 3 in the main scanning direction, the liquid is discharged to the stopped sheet material 10 and one line is recorded. Then, after the sheet material 10 is conveyed in a predetermined amount, the next row is recorded.

When the recording end signal or the signal that the rear end of the sheet material 10 reaches the recording area is received, the printing operation is ended and the sheet material 10 is discharged to a paper ejection tray (not shown).

Next, an example of the liquid discharge head will be described with reference to FIGS. 3 and 4. FIG. 3 is a cross-sectional explanatory view of the head in a direction orthogonal to the nozzle arrangement direction (longitudinal direction of the liquid chamber), and FIG. 4 is a cross-sectional explanatory view of the same nozzle arrangement direction (short side of the liquid chamber).

This liquid discharge head joins the nozzle plate 101, the flow path plate 102, and the diaphragm member 103. A piezoelectric actuator 111 that displaces the diaphragm member 103 and a frame member 120 as a common flow path member are provided.

As a result, a liquid supply that also serves as a fluid resistance unit that supplies liquid to the individual liquid chambers (also referred to as pressure chambers, pressurizing chambers, etc.) 106 and the individual liquid chambers 106 that communicate with the plurality of nozzles 104 that discharge droplets. A passage 107 and a liquid introduction portion 108 leading to the liquid supply passage 107 are formed. The adjacent individual liquid chambers 106 are separated by a partition wall 106A in the nozzle arrangement direction.

Then, the liquid is supplied from the common liquid chamber 110 as the common flow path of the frame member 120 to the plurality of individual liquid chambers 106 through the filter portion 109 formed in the diaphragm member 103, the liquid introduction portion 108, and the liquid supply passage 107. ..

The piezoelectric actuator 111 is arranged on the side opposite to the individual liquid chamber 106 with the deformable vibration region 130 forming the wall surface of the individual liquid chamber 106 of the diaphragm member 103 interposed therebetween.

The piezoelectric actuator 111 has a plurality of laminated piezoelectric members 112 joined on the base member 113. The piezoelectric member 112 is grooved by half-cut dicing to form a columnar piezoelectric element (piezoelectric column) 112A that gives a drive waveform and a column 112B in a comb-teeth shape at predetermined intervals.

Then, the piezoelectric element 112A is joined to the island-shaped convex portion 103a formed in the vibration region 130 of the diaphragm member 103. Further, the support column 112B is joined to the convex portion 103b of the diaphragm member 103.

The piezoelectric member 112 is formed by alternately stacking piezoelectric layers and internal electrodes, and the internal electrodes are respectively drawn out to the end faces to provide external electrodes, which can be used to give a drive waveform to the external electrodes of the piezoelectric element 112A. An FPC 115 as a flexible wiring board having flexibility is connected.

The frame member 120 is formed with a common liquid chamber 110 to which liquid is supplied from the head tank 42.

In this liquid discharge head, for example, by lowering the voltage applied to the piezoelectric element 112A from the intermediate potential, the piezoelectric element 112A contracts, the vibration region 130 of the vibrating plate member 103 decreases, and the volume of the individual liquid chamber 106 expands. As a result, the liquid flows into the individual liquid chamber 106.

After that, the voltage applied to the piezoelectric element 112A is increased to extend the piezoelectric element 112A in the stacking direction, and the vibration region 130 of the diaphragm member 103 is deformed in the nozzle 104 direction to contract the volume of the individual liquid chamber 106. As a result, the liquid in the individual liquid chamber 106 is pressurized, and the liquid is discharged (injected) from the nozzle 104.

Then, the vibration region 130 of the diaphragm member 103 is restored to the initial position by returning the voltage applied to the piezoelectric element 112A to the intermediate potential. As a result, the individual liquid chamber 106 expands and a negative pressure is generated, so that the liquid is filled into the individual liquid chamber 106 from the common liquid chamber 110 through the liquid supply path 107. Therefore, after the vibration of the meniscus surface of the nozzle 104 is attenuated and stabilized, the operation for the next ejection is started.

Next, the outline of the control unit of this device will be described with reference to FIG. FIG. 5 is a block explanatory view of the control unit.

The control unit 500 includes a CPU 501 that controls the entire device, a ROM 502 that stores fixed data such as various programs including programs executed by the CPU 501, and a main control unit 500A that includes a RAM 503 that temporarily stores image data and the like. ing.

The control unit 500 includes a rewritable non-volatile memory 504 for holding data even while the power of the device is cut off. The control unit 500 includes an ASIC 505 that processes various signal processing for image data, image processing for sorting, and other input / output signals for controlling the entire device.

The control unit 500 includes a print control unit 508 including a data transfer means for driving and controlling the liquid discharge head 41, and a drive IC (here, a drive IC including a drive waveform generator according to the present invention for driving the liquid discharge head 41). It is referred to as a "head driver") 509.

The control unit 500 is connected to the main scanning motor 5 that moves and scans the carriage 3, the sub-scanning motor 16 that orbits the transport belt 12, the caps 21 and 22 of the maintenance and recovery mechanism 20, the movement of the wiper member 23, and the cap 21. A motor drive unit 510 for driving the maintenance / recovery motor 556 that drives the suction means and the like is provided.

The control unit 500 includes a supply system drive unit 512 that drives the liquid supply pump 54 of the liquid supply pump unit 52.

The control unit 500 has an I / O unit 513. The I / O unit 513 can process various sensor information, and acquires information from various sensor groups 515 mounted on the device. Then, the information necessary for controlling the device is extracted and used for controlling the print control unit 508 and the motor drive unit 510. The sensor group 515 includes an optical sensor for detecting the position of the sheet material 10, an interlock switch for detecting the opening / closing of the cover, and the like.

An operation panel 514 for inputting and displaying information necessary for this device is connected to the control unit 500.

Here, the control unit 500 has an I / F 506 for sending and receiving data and signals to and from the host side, and is a cable or a network from the host 600 side such as an information processing device such as a personal computer or an image reading device. It is received by I / F 506 via.

Then, the CPU 501 of the control unit 500 reads out the print data in the reception buffer included in the I / F 506, analyzes the print data, performs necessary image processing, data rearrangement processing, and the like on the ASIC 505, and print-controls this image data. Transfer from unit 508 to head driver 509. In order to output an image, the 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 image data as serial data, and also transfers the transfer clock, latch signal, and the like necessary for transferring the image data and confirming the transfer to the head driver 509. Further, the print control unit 508 selects a plurality of types of drive waveform data stored and held in the ROM 502 and outputs the basic drive waveform data to the head driver 509.

The head driver 509 is based on the image data corresponding to one line of the liquid discharge head 41 serially transferred from the print control unit 508, the drive waveform data transferred from the print control unit 508, and the like, and the liquid discharge head 41. The liquid discharge head 41 is driven by generating and outputting a discharge drive waveform for each piezoelectric element 112A as the pressure generating means.

Next, an example of the head driver will be described with reference to the block explanatory diagram of FIG.

The head driver 509 also serves as a drive waveform generator according to the present invention, and includes a shift register 711, a latch circuit 712, a waveform data storage unit 713, a waveform generation unit 714, an adjacent data detection unit 715, and a D /. It includes an A converter 716 and an amplifier 717.

Here, the waveform data storage unit 713, the waveform generation unit 714, the adjacent data detection unit 715, the D / A converter 716, and the amplifier 717 are used for each piezoelectric element 112A (hereinafter referred to as “PZT”). It is provided and constitutes a means for generating a drive waveform for each of a plurality of pressure generating means corresponding to the plurality of nozzles 104 of the liquid discharge head 41.

The shift register 711 inputs the transfer clock (shift clock) from the print control unit 508 and serial image data (gradation data: 2 bits / 1 channel (1 nozzle)) for one nozzle row. The latch circuit 712 shifts. Each register value of register 711 is latched by a latch signal.

The waveform data storage unit 713 stores and holds the basic drive waveform data transferred from the print control unit 508. A plurality of types of drive waveform data are stored and held in the ROM 502 according to the ambient temperature and other conditions, and the drive waveform data corresponding to the detected ambient temperature and other predetermined conditions is read out to obtain the basic drive waveform. It is transferred as data to the waveform data storage unit 713.

The adjacent data detection unit 715 inputs the gradation data Dn of the target nozzle and the gradation data Dn-1 and Dn + 1 of the adjacent nozzles that are adjacent to the target nozzle, and determines whether or not the adjacent nozzle is ejected and the droplet to be ejected. The type (drop type) related to the size of is detected as information correlating with the type of drive waveform given to the pressure generating means corresponding to the adjacent nozzle.

Here, there is a one-to-one correspondence between the gradation data and the information regarding the size of the droplet. For example, the gradation data 0 is no ejection, the gradation data 1 is a small drop, and the gradation data 2 is a large drop.

The waveform generation unit 714 reads the basic drive waveform data corresponding to the latched gradation data Dn of the latch circuit 712 from the waveform data storage unit 713. Then, the data obtained by changing (correcting) the waveform shape of the basic drive waveform given to the target nozzle according to the presence / absence of ejection of the adjacent nozzle detected by the adjacent data detection unit 715 and the type of droplet to be ejected is output as the drive waveform data. ..

The drive waveform data from the waveform generator 714 is D / A converted by the D / A converter 716, predetermined amplification is performed by the amplifier 717, and is given to the corresponding piezoelectric element PZT as the drive waveform VD.

Next, an example of the drive waveform generated by the drive waveform generator will be described with reference to FIG. 7. FIG. 7 is an explanatory diagram of drive waveforms for small droplets and large droplets.

The drive waveform for ejecting small droplets (discharge drive waveform for small droplets) shown in FIG. 7A is composed of a drive pulse P1. The drive pulse P1 includes an expansion waveform element (pull-in waveform element) a, a retention waveform element b, and a contraction waveform element (push-in waveform element) c.

The expansion waveform element a of the drive pulse P1 descends from the intermediate potential Vm to expand the individual liquid chamber 106. The holding waveform element b holds the falling potential of the expansion waveform element a for a certain period of time. The contraction waveform element c rises to an intermediate potential Vm from the potential held by the retention waveform element b (falling potential due to the expansion waveform element a), contracts the individual liquid chamber 106, and discharges the liquid. The voltage value of the drive pulse P1 (potential difference from the intermediate potential to the falling potential) is Va.

The drive waveform (discharge drive waveform for large droplets) for discharging large droplets shown in FIG. 7B is composed of drive pulses P2 and P3. The drive pulses P2 and P3 also include an expansion waveform element (pulling waveform element) a, a holding waveform element b, and a contraction waveform element (pushing waveform element) c.

The drive pulse P2 is a waveform having a voltage value of Vb, and the drive pulse P3 is a waveform having a voltage value of Vc (Vb <Vd).

By merging the droplets discharged by these drive pulses P2 and P3, a large droplet having a larger amount of droplets than a small droplet is formed.

Next, the adjacent crosstalk will be described with reference to FIGS. 8 and 9. FIG. 8 is an explanatory diagram showing an example of the relationship between the droplet type ejected from the adjacent nozzle adjacent to the target nozzle and the ejection speed of the target nozzle, and FIG. 9 is a schematic explanatory diagram provided for explaining the driving conditions of FIG.

Here, as shown in FIG. 9, the target nozzle among the nozzles A, B, and C is the nozzle B, and the nozzles adjacent to the target nozzle B are the adjacent nozzles A and C. In addition, there are two types of droplets (droplets) to be ejected: small droplets and large droplets.

As shown in FIG. 9A, the ejection speed when ejecting small droplets from the target nozzle B in a state where the adjacent nozzles A and C on both sides are not ejecting is “1” as shown in FIG. 8A. "(Standard).

Here, as shown in FIG. 9B, when the small droplets are discharged from the target nozzle B, the small droplets are also discharged from the adjacent nozzles A and C. In this case, since the pressure propagates in substantially the same phase through the partition wall 106A between the individual liquid chambers 106 of the nozzles A, B, and C, the ejection speed of the droplets of the target nozzle B is as shown in FIG. 7 (b). It becomes larger (faster) than "1".

On the other hand, as shown in FIG. 9C, when the small droplets are ejected from the target nozzle B, the large droplets are ejected from the adjacent nozzles A and C. In this case, the discharge speed becomes smaller (slower) than "1" as shown in FIG. 8C, for example, because the phases of the pressure changes of the individual liquid chambers 106 of the nozzles A, B, and C are different.

In this way, if crosstalk occurs in which the ejection speed of the droplets ejected from the target nozzle fluctuates depending on the ejection state (presence or absence of ejection, droplet type) of the nozzles adjacent to the target nozzle, for example, the landing position shift occurs. Become.

Therefore, in the present invention, the waveform shape of the drive waveform given to the pressure generating means of the target nozzle is changed according to the discharge state of the nozzle adjacent to the target nozzle to reduce the fluctuation of the discharge speed. An embodiment of changing the waveform shape of the drive waveform using the correction value table will be described below.

First, the generation of the drive waveform according to the first embodiment of the present invention will be described with reference to FIG. FIG. 10 is an explanatory diagram of an example of a correction value table in the same embodiment.

In the present embodiment, the adjacent data detection unit 715 detects the ejection state of the adjacent nozzle as a nozzle adjacent to the target nozzle.

The waveform generation unit 714 uses a correction value table as shown in FIG. 10, and uses a correction value table as shown in FIG. Here, the voltage adjustment value [%] is determined.

Then, the waveform generation unit 714 corrects (adjusts) the voltage value of the basic drive waveform data (drive waveform data in which the correction value becomes “0”) stored and held in the waveform data storage unit 713 according to the voltage adjustment value. Output the driven waveform data.

As a result, the voltage values of the drive waveform (the above-mentioned peak values Va, Vb, Vc) are corrected to generate drive waveform data in which the waveform shape is changed, and the drive waveform is generated and given to the pressure generating means. .. Although the entire drive waveform is corrected by the correction value here, a configuration in which only the voltage value of a predetermined one or two or more drive pulses is corrected when there are a plurality of drive pulses can be adopted.

Here, in the correction value table shown in FIG. 10, the correction value (adjustment value) when the adjacent nozzles on both sides of the target nozzle are non-ejection is set to "0", and the adjacent nozzle is set for each droplet type discharged from the target nozzle. The adjustment values of the voltage values are tabulated in advance for the presence or absence of discharge and the type of droplets to be discharged.

Such a correction value table is created, for example, as follows.

For example, as in FIG. 9, the target nozzle is nozzle B, the adjacent nozzles among the adjacent nozzles are nozzle (left nozzle) A, and nozzle (right nozzle) C. Then, the nozzle B and the ejection states of the left and right nozzles A and C are combined, and in each combination, the change in the ejection speed of the droplet of each droplet type of the target nozzle B is measured, and the ejection speed is kept constant. Calculate the correction value to be calculated and create a table.

Next, a specific example of correction of the discharge drive waveform for each nozzle using the correction value table of FIG. 10 will be described with reference to FIG.

In this example, eight nozzles 1 to 8 form one nozzle row, and nozzles 1 and 8 are nozzles at both ends.

Since the ejection droplets of the target nozzle 1 are large droplets, there is no left nozzle, and the nozzle 2 which is the right nozzle is a small droplet, the correction value of the target nozzle 1 is "4". That is, the corrected large-drop discharge drive waveform in which the voltage value (peak height value) of the large-drop discharge drive waveform held in the waveform data storage unit 713 is greatly corrected by "4%" is generated and output.

Similarly, since the target nozzle 2 is a small drop, the nozzle 1 that is the left nozzle is a large drop, and the nozzle 3 that is the right nozzle is non-discharge, the correction value of the target nozzle 2 is “3”. Since the target nozzle 5 is a small drop, the nozzle 4 which is the left nozzle is non-discharge, and the nozzle 6 which is the right nozzle is a large drop, the correction value of the target nozzle 5 is “3”.

Since the target nozzle 6 is a large drop, the nozzle 5 that is the left nozzle is a small drop, and the nozzle 7 that is the right nozzle is a large drop, the correction value of the target nozzle 6 is “2”. Since the target nozzle 7 is a large drop, the left nozzle 6 is a large drop, and the right nozzle 8 is a small drop, the correction value of the target nozzle 7 is “2”. Since the ejection droplets of the target nozzle 8 are small droplets, the left nozzle is a large droplet, and there is no right nozzle, the correction value of the target nozzle 8 is "3".

By performing such correction, the variation in the ejection speed due to crosstalk is reduced, the variation in the landing position is reduced, and the image quality is improved, for example.

When the correction is performed by adjusting the voltage value of the discharge drive waveform as in the above embodiment, any combination of discharge states as a reference of the voltage adjustment value may be used, but in the above example of the correction value table, the left and right nozzles In both cases, the case of non-discharge is used as a reference, and the adjustment value from the reference value is set as the correction value.

Further, the correction value table can be created for all the heads mounted on the apparatus, or can be created for one or more representative heads and the values can be applied to all the heads.

Further, the correction of the discharge drive waveform does not have to be performed for all combinations of discharge states, and can be performed only for combinations in which the speed fluctuation of the target nozzle becomes large. In this way, the correction process (process of changing the waveform shape) can be simplified.

Further, although only the adjacent nozzle is used as the nozzle adjacent to the target nozzle, the adjacent nozzle may include the adjacent nozzle. For example, two nozzles on each side of the target nozzle (four nozzles in total) may be adjacent nozzles. This makes it possible to correct the discharge speed more accurately even in a head that is greatly affected by crosstalk.

Further, in the above embodiment, the voltage value of the discharge drive waveform is corrected to change the waveform shape, but the pulse width of the drive pulse, the pulse interval, the inclination of the waveform element, and the natural vibration cycle Tc of the individual liquid chamber are used. It is also possible to change the discharge rate by changing the relationship between the two.

Further, in the above embodiment, the discharge drop type is not limited to the two types of small drop and large drop, and the discharge state is described in the example of non-discharge, small drop discharge, and large drop discharge. For example, it is possible to eject three types of droplets, large, medium, and small, or more. Further, the non-discharge may include a case where the drive waveform is not given and a case where a fine drive waveform (non-discharge drive waveform) that moves the meniscus to the extent that the meniscus is not discharged is given.

Further, in the above embodiment, the ejection speed becomes high when the target nozzle and the droplet type of the adjacent nozzle are the same, and the ejection speed becomes slow when the droplet type of the target nozzle and the adjacent nozzle are different. However, the fluctuation of the discharge speed is not uniform depending on the head configuration. For example, depending on the rigidity of the partition wall between the individual liquid chambers and the height of the individual liquid chambers, even if the target nozzle and the droplet type of the adjacent nozzle are the same, the discharge rate may be slow, or the droplet type of the target nozzle and the adjacent nozzle may be different. Even in this case, the discharge speed may increase. Therefore, the waveform shape of the drive waveform may be changed according to the fluctuation of the discharge speed of the head.

In the present application, the liquid to be discharged may have a viscosity and surface tension that can be discharged from the head, and is not particularly limited, but the viscosity becomes 30 mPa · s or less at room temperature, under normal pressure, or by heating or cooling. It is preferable that it is a thing. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, polymerizable compounds, resins, functionalizing materials such as surfactants, biocompatible materials such as DNA, amino acids and proteins, and calcium. , Solvents, suspensions, emulsions, etc. containing edible materials such as natural pigments, etc., for example, inks for inkjets, surface treatment liquids, components of electronic elements and light emitting elements, and formation of electronic circuit resist patterns. It can be used for applications such as a liquid for use and a material liquid for three-dimensional modeling.

Piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators that use electrothermal conversion elements such as heat-generating resistors, and electrostatic actuators that consist of a vibrating plate and counter electrodes are used as energy sources for discharging liquid. Includes what to do.

Further, the "device for discharging a liquid" includes not only a device capable of discharging a liquid to a device to which the liquid can adhere, but also a device for discharging the liquid toward the air or the liquid. ..

The "device for discharging the liquid" may include means for feeding, transporting, and discharging paper to which the liquid can be attached, as well as a pretreatment device, a posttreatment device, and the like.

For example, as a "device that ejects a liquid", an image forming apparatus that ejects ink to form an image on paper, and a three-dimensional object (three-dimensional object) are formed in layers in order to form a three-dimensional object. There is a three-dimensional modeling device (three-dimensional modeling device) that discharges the modeling liquid into the powder layer.

Further, the "device for discharging a liquid" is not limited to a device in which a significant image such as characters and figures is visualized by the discharged liquid. For example, those that form patterns that have no meaning in themselves and those that form a three-dimensional image are also included.

The above-mentioned "material to which a liquid can adhere" means a material to which a liquid can adhere at least temporarily, such as one that adheres and adheres, and one that adheres and permeates. Specific examples include paper, recording paper, recording paper, film, recording media such as cloth, electronic substrates, electronic components such as piezoelectric elements, powder layers (powder layers), organ models, and media such as inspection cells. Yes, including anything to which the liquid adheres, unless otherwise specified.

The material of the above-mentioned "material to which liquid can be attached" may be paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics or the like as long as the liquid can be attached even temporarily.

Further, the "device for discharging the liquid" includes, but is not limited to, a device in which the liquid discharge head and the device to which the liquid can adhere move relatively. Specific examples include a serial type device that moves the liquid discharge head, a line type device that does not move the liquid discharge head, and the like.

In addition, as a "device for ejecting a liquid", a treatment liquid coating device for ejecting a treatment liquid to a paper in order to apply the treatment liquid to the surface of the paper for the purpose of modifying the surface of the paper, etc. There is an injection granulation device that granulates fine particles of the raw material by injecting a composition liquid in which the raw material is dispersed in a solution through a nozzle.

In addition, image formation, recording, printing, printing, printing, modeling, etc. in the terms of the present application are all synonymous.

40 Liquid discharge unit 41 Liquid discharge head (head)
106 Individual liquid chamber 500 Control unit 509 Head driver (drive waveform generator)
713 Waveform data storage unit 714 Waveform generation unit 715 Adjacent data detection unit

Claims (6)

A device that generates and outputs a drive waveform to discharge liquid from the liquid discharge head.
A means for generating the drive waveform is provided for each of the plurality of pressure generating means corresponding to the plurality of nozzles of the liquid discharge head.
The means for generating is
A means for detecting information correlating with the type of the driving waveform given to the pressure generating means corresponding to a nozzle adjacent to the target nozzle and changing the waveform shape of the driving waveform given to the target nozzle according to the detected information. equipped with a,
The information that correlates with the type of the drive waveform is the information on the type of droplets ejected from the nozzle.
When the type of droplets ejected from the adjacent nozzles increases the droplet velocities ejected from the target nozzle, the droplet velocities ejected from the target nozzles decrease.
When the type of droplets ejected from the adjacent nozzles decreases the droplet velocities ejected from the target nozzle, the droplet velocities ejected from the target nozzles are increased.
A drive waveform generator, characterized in that the waveform shape of the drive waveform given to the target nozzle is changed. The drive waveform includes one or more drive pulses.
The drive waveform generator according to claim 1, wherein the voltage value of one or more of the drive pulses is corrected to change the waveform shape. The drive waveform generator according to claim 1 or 2, wherein the adjacent nozzles are nozzles adjacent to the target nozzle. The correction value of the drive waveform given to the pressure generating means corresponding to the target nozzle is stored for each combination of the type of droplets discharged from the target nozzle and the type of droplets discharged from the adjacent nozzles. The drive waveform generator according to any one of claims 1 to 3, further comprising a correction value table. A liquid discharge unit including the drive waveform generator according to any one of claims 1 to 4 and the liquid discharge head. A device for discharging a liquid, which comprises the drive waveform generator according to any one of claims 1 to 4 or the liquid discharge unit according to claim 5.

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