JP2010142978A - Fluid jetting apparatus and fluid jetting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately adjust a strike position of fluid even if a distance between a head and a medium is changed. <P>SOLUTION: The fluid jetting apparatus includes a head which jets the fluid to the medium, a memory in which the distance between the head and the medium and a flying speed of the fluid are stored while being associated with each other, and a control part which changes the jetting timing of the fluid from the head on the basis of flying speed obtained on the basis of the distance. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fluid ejecting apparatus and a fluid ejecting method.

An apparatus for forming an image by ejecting a fluid from a head to a medium is used. In such an apparatus, the thickness of the medium may change due to changes in the medium used, and the distance from the head to the medium may thereby change.
JP 2004-58543 A

  The speed of the fluid changes due to the influence of air resistance after being ejected. Further, the degree of change in speed due to the influence of air resistance and the like varies depending on the distance from the head to the medium. On the other hand, if the landing position of the fluid is estimated on the assumption that the velocity of the fluid is constant even if the distance from the head to the medium changes, the fluid will not land at the place where it should originally land. Then, for example, when an image is formed with a fluid, an appropriate image may not be formed.

  The present invention has been made in view of such circumstances, and is capable of appropriately adjusting the landing position of the fluid even when the distance between the head and the medium changes. The purpose is to provide.

The main invention for achieving the above object is:
A head for ejecting fluid onto the medium;
A storage unit that stores the distance between the head and the medium and the flying speed of the fluid in association with each other;
A control unit that changes the ejection timing of the fluid from the head based on the flying speed obtained based on the distance;
Is a fluid ejection device.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  At least the following matters will become clear from the description of the present specification and the accompanying drawings.

A head for ejecting fluid onto the medium;
A storage unit that stores the distance between the head and the medium and the flying speed of the fluid in association with each other;
A control unit that changes the ejection timing of the fluid from the head based on the flying speed obtained based on the distance;
A fluid ejection device comprising:
By doing so, even if the distance between the head and the medium changes, the landing position of the fluid can be adjusted appropriately.

  The fluid ejecting apparatus further includes a moving mechanism that relatively moves the position of the head and the medium, and the control unit includes a relative moving speed of the head and the medium, the flying speed, and the like. It is desirable to change the ejection timing of the fluid from the head based on the above. The flying speed is preferably an average flying speed between the head and the medium. Further, it is desirable that the distance and the flight speed are associated with each other in a non-linear relationship and stored in the storage unit. Further, the storage unit stores the distance and the flying speed for each dot size formed on the medium, and the control unit calculates the flying speed obtained based on the dot size and the distance. It is desirable to change the ejection timing of the fluid based on the above.

Further, it is preferable that the control unit further changes the ejection timing of the fluid based on the temperature of the fluid.
By doing in this way, even if it is a case where the distance between a head and a medium changes, the landing position of a fluid can be adjusted appropriately.

Determining the flying speed of the fluid based on the distance between the head and the medium;
Changing the ejection timing of the fluid from the head based on the determined flight speed, and ejecting the fluid;
A fluid ejection method comprising:
By doing in this way, even if it is a case where the distance between a head and a medium changes, the landing position of a fluid can be adjusted appropriately.

A head for ejecting fluid to the medium;
A storage unit in which a distance between the head and the medium and a flight time of the fluid corresponding to the distance are associated and stored in a non-linear relationship;
A control unit that changes the timing of ejecting the fluid from the head based on the flight time of the fluid determined based on the distance;
A fluid ejection device comprising:
By doing in this way, even if it is a case where the distance between a head and a medium changes, the landing position of a fluid can be adjusted appropriately.

=== Embodiment ===
FIG. 1A is an external perspective view of the printer 1, and FIG. 1B is an internal perspective view of the printer 1. FIG. 2 is a block diagram of the printer 1. Hereinafter, the configuration of the printer 1 will be described with reference to these drawings.

  The printer 1 includes a paper transport mechanism 20, a carriage movement mechanism 30, a head unit 40, a detector group 50, a controller 60, and a drive signal generation circuit 70. The printer 1 acquires print data from the computer 110 via the interface 61, and prints an image on a sheet based on the print data.

  The controller 60 is realized by, for example, an ASIC and has a program processing function and a storage function for storing the program and the like. These may be realized by a CPU or a memory. The controller 60 controls the paper transport mechanism 20, the carriage movement mechanism 30, the head unit 40, and the drive signal generation circuit 70 in the printer 1.

  Under the control of the controller 60, the paper transport mechanism 20 sends the paper to a printable position or transports the paper in the transport direction by a predetermined transport amount. Under the control of the controller 60, the carriage moving mechanism 30 moves the carriage CR to which the head unit 40 is attached in the carriage moving direction using the carriage CR moving belt 31 and the carriage motor 32.

  The head unit 40 includes a head 41 and a head control circuit (not shown). The head 41 includes a plurality of nozzles that eject ink droplets and a plurality of piezoelectric elements (not shown) for ejecting ink droplets. The head control circuit has a function of controlling ejection of ink droplets from the head 41. Under the control of the head control circuit, a driving pulse of a driving signal COM described later is applied to each piezoelectric element at an appropriate timing.

  The detector group 50 is a plurality of various sensors attached to each part of the printer 1, and sends detection results to the controller 60. For example, in the present embodiment, the detector group 50 includes an ink temperature sensor provided in the head.

  The drive signal generation circuit 70 generates a drive signal COM to be applied to the piezoelectric element. The drive signal generation circuit 70 includes a DAC for generating an analog waveform and a transistor for power amplification. Digital data indicating the shape of the drive waveform to be formed from the controller 60 is sent to the drive signal generation circuit 70. A signal representing the waveform of the drive signal is generated by the DAC based on the sent digital data, and the drive signal COM is generated by power amplification of the signal by the transistor.

  From such a principle, a desired drive signal can be generated by changing digital data sent from the controller 60. For example, it is possible to change the amplitude of the waveform of the drive signal or adjust the generation timing of the drive pulse included in the drive signal as described later.

  FIG. 3A is a view of the head 41 as viewed from below. In the figure, nozzles 439 of each nozzle row are shown. A black ink nozzle row Nk for ejecting black K ink droplets, a cyan ink nozzle row Nc for ejecting cyan C ink droplets, and magenta M. A magenta ink nozzle row Nm for discharging the ink droplets and a yellow ink nozzle row Ny for discharging the yellow Y ink are shown.

  Each of these nozzles is provided with a corresponding piezoelectric element in the head 41. A drive pulse of a drive signal, which will be described later, is selectively applied to each of these piezo elements, whereby a plurality of sizes of ink can be ejected.

  FIG. 3B is a cross-sectional view of the periphery of the nozzle row. Here, a structure for ejecting ink from individual nozzles will be described with reference to FIG.

  The drive unit 42 included in the head 41 includes a plurality of piezo elements 421, a fixed plate 423 to which the piezo element group 421 is fixed, and a flexible cable 424 for supplying power to each piezo element 421. Each piezo element 421 is attached to the fixed plate 423 in a so-called cantilever state. The fixed plate 423 is a plate-like member having rigidity capable of receiving a reaction force from the piezo element 421. The flexible cable 424 is a flexible sheet-like wiring board, and is electrically connected to the piezo element 421 on the side surface of the fixed end opposite to the fixed plate 423. On the surface of the flexible cable 424, a head controller (not shown), which is a control IC for controlling driving of the piezo element 421, is mounted. The head controller is provided for each nozzle group of each head.

  The flow path unit 44 includes a flow path forming substrate 45, a nozzle plate 46, and an elastic plate 47. The flow path forming substrate 45 is laminated and integrated so that the flow path forming substrate 45 is sandwiched between the nozzle plate 46 and the elastic plate 47. Constructed. The nozzle plate 46 is a thin plate made of stainless steel on which nozzles are formed.

  In the flow path forming substrate 45, a plurality of vacant portions serving as pressure chambers 451 and ink supply ports 452 are formed corresponding to the respective nozzles. The reservoir 453 is a liquid storage chamber for supplying the ink stored in the ink cartridge to each pressure chamber 451, and communicates with the other end of the corresponding pressure chamber 451 through the ink supply port 452. Then, the ink from the ink cartridge is introduced into the reservoir 453 through an ink supply pipe (not shown). The elastic plate 47 includes an island portion 473. The tip of the free end portion of the piezo element 421 is bonded to the island portion 473.

When a drive signal is supplied to the piezo element 421 via the flexible cable 424, the piezo element 421 expands and contracts to expand and contract the volume of the pressure chamber 451. Due to such a change in the volume of the pressure chamber 451, pressure fluctuation occurs in the ink in the pressure chamber 451. Then, ink can be ejected from the nozzles by utilizing the fluctuation of the ink pressure.
The supplied drive signal will be described in detail later.

  FIG. 4 is a diagram for explaining the delay time of liquid ejection. The printer 1 according to the present embodiment can eject ink by changing the ejection timing with respect to a reference time for ejecting ink. This is because, as shown below, if the flying speed of the ink changes due to the change in the platen gap PG, the ink landing position changes, so the ink ejection timing is changed to change the ink to an appropriate position. It is intended to land.

  The figure shows the first speed Vcr1 of the carriage CR when the first platen gap PG1, the second platen gap PG2, the first platen gap PG1, the second speed Vcr2 of the carriage CR when the second platen gap PG2, The average ink speed Vm1 (hereinafter referred to as the first average speed) at the time of the platen gap PG1 and the average speed Vm2 (hereinafter referred to as the second average speed) of the ink at the time of the second platen gap PG2 are shown. The first platen gap PG1 is a reference platen gap PG1 in the printer 1, and is a platen gap set by default. Further, the first speed Vcr1 of the carriage CR at this time is a moving speed at the time of the reference platen gap. The average ink velocity Vm1 at this time is a reference first average velocity, which is an average velocity set by default.

  Here, the platen gap PG is the distance from the ink ejection surface of the head to the landing position on the medium. The average ink velocity Vm is the average ink velocity from the time the ink is ejected until the ink lands. Here, the reason why the flying speed of the ink is shown as the average speed is that the speed of the ink after being ejected changes due to the influence of air resistance.

Further, the drawing shows the first landing position L1 of the ink at the time of the first platen gap PG1, the second landing position L2 of the ink at the time of the second platen gap PG2, and the deviation amount L of the landing position. Yes. From the relationship shown in the figure, the first landing position L1 and the second landing position L2 are
L1 = PG1 / Vm1 × Vcr1
L2 = PG2 / Vm2 × Vcr2
It is. And the deviation amount ΔL of the landing position is
ΔL = L2-L1
It becomes.

Assuming that the first speed Vcr1 and the second speed Vcr2 of the carriage CR are the same, the delay time ΔT of the ink ejection time due to the difference in the platen gap and the average speed is
ΔT = −ΔL / Vcr2
= PG1 / Vm1-PG2 / Vm2 (Formula 1)
It becomes.

  Here, (Equation 1) is derived based on delaying the injection timing. Therefore, in the above equation, when the value of ΔT is positive, the injection timing is delayed with respect to the reference time. On the other hand, when the value of ΔT is negative, the injection timing is advanced with respect to the reference time. In the following description, the “delay time ΔT” of ink ejection will be described, but it should be noted that the ejection timing is not necessarily delayed but may be accelerated.

  FIG. 5A is a graph showing the average speed of ink with respect to the distance between the head and the medium. The “distance” here is a distance from the ejection nozzle hole of the head to the medium. In the figure, the horizontal axis is the platen gap PG (that is, the distance between the head and the medium), and the vertical axis is the average speed Vm. FIG. 5B is a table showing the average speed of ink with respect to the distance between the head and the medium. The figure shows the average speed of the ink changing as the platen gap increases. In the figure, the average speed Vm when the average speed Vm at 25 ° C. is used as a reference (100%) is shown.

  According to the above equation (1), if the average speed of the ink is constant even if the platen gap changes, the ink ejection timing may be delayed by the change in the platen gap. However, the actual average ink speed changes with the change of the platen gap, and the amount of change is not constant. The change in average speed is non-linear with respect to the change in platen gap. This is considered to be because as the platen gap becomes larger, the speed of the ink droplets is more likely to decrease in speed due to air resistance.

  FIG. 6A is a graph showing the arrival time of ink with respect to the distance between the head and the medium. The arrival time here is the time from ink ejection until landing on the medium. In the figure, the horizontal axis is the platen gap, and the vertical axis is the arrival time. FIG. 6B is a table showing the ink arrival time with respect to the distance between the head and the medium. In the figure, the arrival time of ink, which changes as the platen gap increases, is shown. In the figure, the arrival time when the arrival time at 25 ° C. is used as a reference (100%) is shown.

  In the figure, in the region where the platen gap is small (for example, 0.5 mm to 1.0 mm), the relationship between the platen gap and the arrival time is substantially proportional. However, as the platen gap gradually increases, the relationship between the platen gap and the arrival time is not proportional. As described above, it is considered that as the platen gap becomes larger, the speed of the ink droplet is more likely to decrease due to the air resistance, and more time is required to land.

  FIG. 7 is a graph showing the amount of landing deviation of ink with respect to the distance between the head and the medium. In the figure, the horizontal axis is the platen gap, and the vertical axis is the amount of deviation of the landing position. The average speed of the ink is constant regardless of the size of the platen gap.

  Referring to the drawing, the amount of landing deviation in a region where the platen gap is small (for example, 0.5 mm to 1.0 mm) is small. On the other hand, as the platen gap increases, the amount of landing deviation increases. This is presumably because, as described above, as the platen gap becomes larger, the speed of the ink droplets decreases due to the air resistance, thereby increasing the arrival time.

  As described above, when the platen gap changes, if the ink ejection timing is delayed with the average ink speed kept constant, the ink will be landed out of the actual landing position. In this embodiment, the ink ejection timing is obtained in consideration of the change in the average speed of the ink with respect to the change in the platen gap.

FIG. 8 is a flowchart for explaining an ink ejection timing delay process in the present embodiment.
First, a platen gap is obtained (S102). In this embodiment, the platen gap is obtained by selecting the paper type via the printer driver. For example, when printing on a thick sheet, the platen gap is reduced by the thickness, and when printing on a thin sheet, the platen gap is increased. In the printer driver according to the present embodiment, the thicknesses of a plurality of types of paper are registered. When a paper is selected, the thickness of the paper is read, and a platen gap is set according to the read thickness. It will be required.
Note that the platen gap may be dynamically obtained by attaching a sensor for obtaining the distance from the paper to the head.

  Next, a delay time of ink droplet ejection timing is obtained based on the obtained platen gap (S104). The delay time ΔT is obtained by substituting each value into the above-described equation (1). In the present embodiment, the average speed is obtained based on the platen gap. For this purpose, an average speed table as shown in FIG. 5B is stored in the memory of the printer 1 in advance.

  Here, the first platen gap PG1 is a reference value in the printer 1, and a default value is used. The printer 1 is designed so that ink can land at an appropriate position at the first average speed Vm1 at the time of the first platen gap PG1. That is, in the printer 1, the first platen gap PG1 and the first average speed Vm1 are constant values. Further, the value obtained in step S102 is used for the second platen gap PG2.

  Then, the first average speed Vm1 and the second average speed Vm2 corresponding to the obtained first platen gap PG1 and second platen gap PG2 are obtained by referring to the above-described average speed table. Since the average speed table shown in FIG. 5B has a small amount of data, these values may be interpolated and used, or more detailed data may be prepared in advance.

  The first platen gap PG1, the second platen gap PG2, the first average speed Vm1 and the second average speed Vm2 thus determined are substituted into (Equation 1) to determine the delay time ΔT.

  Then, the printer 1 ejects ink while delaying the ink ejection time by the obtained delay time ΔT (S106). In this way, even when the platen gap changes and thereby the average speed of the ink also changes, the ink droplet can be landed at an appropriate position on the medium. Such an operation is continuously performed, whereby an image having an appropriate shape is formed on the medium.

  Incidentally, here, the delay time ΔT is obtained based on the average speed of the ink, but the delay time ΔT may be obtained based on the arrival time of the ink. When the ejection timing is changed based on the ink arrival time, an ink arrival time table for the platen gap PG as shown in FIG. 6B is prepared and stored in the memory of the printer 1 in advance. In step S104, the first average velocity of ink as described above can be obtained by dividing the first platen gap PG1 by the corresponding arrival time. Similarly, the second average velocity of ink as described above can be obtained by dividing the second platen gap PG2 by the corresponding arrival time. Then, the delay time ΔT may be obtained based on the first platen gap PG1, the second platen gap PG2, the first average speed Vm1, and the second average speed Vm2 thus obtained.

  In this way, the ink ejection timing can be changed based on the ink arrival time. The ink arrival time in the present embodiment corresponds to the ink flight time.

<Considering changes in head movement speed>
In the above description, the case where the moving speed of the head is constant has been described. However, the moving speed of the head is not constant and may be different from the moving speed of the reference head. In (Expression 1), the expression is derived assuming that the first speed Vcr1 and the second speed Vcr2 of the carriage CR are the same speed, but here, the first speed Vcr1 and the second speed Vcr2 are different speeds. To do. Then, the delay time ΔT of the ink ejection timing is
ΔT = −ΔL / Vcr2
= (PG1 / Vm1) × (Vcr1 / Vcr2− (PG2 / PG1) / (Vm2 / Vm1))
(Formula 2)
It becomes. Therefore, in step S104, the delay time ΔT is obtained using (Expression 2) instead of (Expression 1). As described above in (Equation 2), the first speed Vcr1 is the movement speed of the carriage CR when the first platen gap PG1, and the second speed Vcr2 is the movement of the carriage CR when the second platen gap PG2. Is speed.

  In this way, ink can be landed at an appropriate position even when the moving speed of the head changes.

<In consideration of temperature>
FIG. 9A is a graph showing the average speed of ink when the temperature change of ink is taken into consideration. FIG. 9B is a table showing the average speed of ink when the temperature change of ink is taken into consideration. In the figure, the average speed Vm when the average speed Vm at 25 ° C. is used as a reference (100%) is shown.

  The viscosity of a fluid such as ink changes depending on its temperature. When the viscosity changes, the average speed of the ink also changes due to the influence. In the figure, the higher the ink temperature, the lower the average speed, and the lower the ink temperature, the higher the average speed.

When the viscosity of the ink changes, the weight of the ink ejected from the nozzle changes. In the case of the high temperature side, since the viscosity of the ink is lowered, the vibration amplitude of the ink in the pressure chamber 451 is increased, the weight of the ink ejected from the nozzle is increased, and the speed is increased. For this reason, normally, the drive condition is corrected so as to reduce the deformation amount of the piezo element and keep the ink weight constant. Since the ink speed change rate with respect to the deformation amount of the piezo element is larger than the ink weight change rate, the ink speed is reduced by correcting the driving conditions.
On the low temperature side, since the viscosity of the ink is increased, the correction is made opposite to the high temperature side. As a result, the ink speed increases.

  Therefore, in the present embodiment, a plurality of average speed tables may be prepared for each ink temperature. In this case, a temperature sensor is provided inside the head, and the temperature related to ink is sent to the controller 60. Then, the controller 60 selects an average speed table to be used according to the acquired temperature of the ink inside the head. Then, the first platen gap PG1, the second platen gap PG2, the first average speed Vm1, and the second average speed Vm2 are obtained from the selected average speed table. Based on these, the ink ejection delay time ΔT is obtained.

  In this way, ink can be ejected at a more appropriate timing according to the temperature environment.

An ink arrival time table may be prepared for each ink temperature.
FIG. 10A is a graph showing the arrival time of ink when temperature change is taken into consideration. FIG. 10B is a table showing the ink arrival time when temperature change is considered. In the figure, the arrival time when the arrival time at 25 ° C. is used as a reference (100%) is shown.

  At this time, the arrival time table to be used is selected based on FIG. 10B. Then, using the selected arrival time table, the first average speed Vm1 and the second average speed Vm2 are obtained from the first platen gap PG1 and the second platen gap PG2. The injection timing delay time ΔT may be obtained based on these values.

  This also makes it possible to eject ink at a more appropriate timing according to the temperature environment.

<In consideration of ink droplet size>
Even when the size of the ejected ink droplets is different, the average speed of the ink may be different. This is because air resistance and the like for different ink droplet sizes differ.
In consideration of the size of the ink droplet, for example, a small ink droplet for forming a small dot (corresponding to a first size dot) and a medium ink for forming a medium dot (corresponding to a second size dot). For each of the three types of ink droplets, a large ink droplet for forming a droplet and a large dot, the average speed of the ink with respect to the platen gap PG can be obtained in advance. These are stored in advance in the memory of the printer 1.

FIG. 11A is a table showing a delay time for each size of ejected ink droplets. In the figure, the size of the ink droplets to be ejected and the corresponding delay times (ΔTs (corresponding to the first delay time), ΔTm (corresponding to the second delay time), ΔTl) are shown. Such a delay time table is stored in the memory of the printer 1 in advance. A delay time ΔT is obtained for each ink size. The ejection timing is delayed by a delay time ΔT from the reference ejection timing for each ink size, and ink is ejected.
In this way, ink can be ejected at an appropriate timing according to the difference in the size of the ink droplets.

  FIG. 11B is a table showing the average speed with respect to the platen gap PG for each size of the ejected ink droplets. The figure shows an average speed table in which the average speed is associated with the platen gap PG corresponding to the size of each ink droplet.

  When the delay table of FIG. 11A described above is used, the delay time is uniformly determined for each ink droplet size, but the average velocity for the platen gap PG is associated with each ink droplet size. The average speed table can also be stored in the memory. In this manner, in step S104, the first platen gap PG1, the second platen gap PG2, the first average speed Vm1, and the second average speed Vm2 can be obtained for each ink size. Then, by substituting these into (Equation 1) or (Equation 2), the delay time ΔT corresponding to the ink size can be obtained.

  FIG. 11C is a table showing the arrival time with respect to the platen gap PG for each size of the ejected ink droplet. The drawing shows an arrival time table in which the arrival times for the platen gap PG are associated with each ink droplet size. As described above, the arrival time table as shown in FIG. 11C is stored in the memory of the printer 1, and the first platen gap PG1 and the second platen gap PG2 for each size of the ejected ink droplets are stored. The average speed Vm1 and the second average speed Vm2 can also be obtained. And based on these calculated | required values, the delay time of ejection can be calculated | required for every magnitude | size of an ink drop from (Formula 1) or (Formula 2).

  In this way, the ejection delay time ΔT according to the size of the ejected ink droplet can be obtained.

  Also, an ink average speed table may be prepared and stored for each ink droplet size for each ink temperature. In this way, it is possible to eject ink with different ejection delay times for each ink size according to the ink temperature.

<Method of delaying ink ejection timing>
In the above description, the method for obtaining the delay time of the ink ejection timing has been described. Here, a method of ejecting ink by delaying the ejection timing based on the obtained delay time will be described.

  FIG. 12 is a diagram for explaining the drive signal COM. In the figure, the drive signal generated by the drive signal generation circuit 70 is shown. As the drive signal, a drive signal during a repetition period T is repeatedly generated. The time of the repetition period T corresponds to one pixel at the relative movement speed of the head and the paper S.

  The drive signal COM includes a first drive pulse PS1, a second drive pulse PS2, a third drive pulse PS3, and a fourth drive pulse PS4. In one pixel, one of these drive pulses is selectively applied to the piezo element of each nozzle, and ink droplets for forming dots of each size are ejected.

  In the present embodiment, three types of sizes of large dots, medium dots, and small dots can be formed. The first drive pulse PS1 is generated in the section T1, and when this drive pulse is applied to the piezo element, an ink droplet for forming a medium dot is ejected. The second drive pulse PS2 is generated in the section T2, and when this drive pulse is applied to the piezo element, the ink surface in the nozzle is slightly vibrated and the ink is not ejected. The third drive pulse PS3 is generated in the section T3. When this drive pulse is applied to the piezo element, an ink droplet for forming a large dot is ejected. The fourth drive pulse PS4 is generated in the section T4. When this drive pulse is applied to the piezo element, an ink droplet for forming a small dot is ejected.

  Ink ejection timing can be changed by shifting the generation timing of these pulses. For example, in the first drive pulse PS1, the generation timing is shifted by ΔT1 from the first drive pulse PS1 indicated by the solid line as a reference. At this time, the generation timings of the third drive pulse PS3 and the fourth drive pulse PS4 may be similarly delayed by ΔT1, or the generation timing is delayed by ΔT3 for the third drive pulse and ΔT4 for the fourth drive pulse. It is good.

  By doing in this way, the ejection timing of the ink ejected in order to form each size dot can be changed.

  FIG. 13 is a diagram for explaining a plurality of drive signals COM1 to COM4 generated simultaneously. Here, the drive signal generation circuit 70 generates a plurality of drive signals. The first drive signal COM1 includes the first drive pulse PS1 described above. The second drive signal COM2 includes the second drive pulse PS2 described above. The third drive signal COM3 includes the above-described third drive pulse PS3. The third drive signal COM4 includes the aforementioned fourth drive pulse PS4.

  When the drive signal shown in FIG. 12 is used, the drive pulse used from the drive signal is selectively applied to the piezo element. However, when the drive signal has a plurality of drive signals as shown in FIG. The driving pulse to be used is selectively applied to the piezo element every period T.

  Also at this time, the ink ejection timing can be changed by shifting the generation timings ΔT1, ΔT3, and ΔT4 of these pulses.

  FIG. 14 is a diagram (part 1) for explaining the arrangement of dots indicated by pixel data. In the figure, each grid-like section is shown, and each of these shows a pixel. In the drawing, the position of each pixel is shown as a two-dimensional coordinate. Further, the drawing shows the carriage movement direction and the paper conveyance direction for each pixel.

  The pixel data is data indicating in which pixel a dot is to be formed. FIG. 14 is a visual representation of the dot arrangement indicated by the pixel data. According to the pixel data at this time, dots are formed at (i + 2, j), (i + 2, j + 1), and (i + 2, j + 2).

  However, as described above, depending on the size of the platen gap, it is necessary to delay the ink ejection timing. Although the ejection timing can be delayed by shifting the generation timing of each drive pulse, the range is within a range of one pixel corresponding to one cycle of the drive signal at the maximum. Then, when the ejection timing is shifted in a wider range, it is necessary to regenerate the pixel data so as to shift the arrangement of dots to be formed.

  FIG. 15 is a diagram (No. 2) for explaining the arrangement of dots indicated by pixel data. For example, in the case where the ejection of ink for two pixels must be delayed in consideration of the moving speed of the carriage in order to form dots at positions 1 to 3 surrounded by a circle shown in FIG. The pixel data is recreated so that the dot arrangement indicated by the pixel data becomes the arrangement shown in FIG. That is, the pixel data is recreated as if dots are formed at (i, j), (i, j + 1), (i, j + 2). In this manner, the ink ejection timing can be substantially changed by recreating the pixel data. At this time, the ink ejection time can be delayed by the time obtained by dividing the distance between the pixels to be shifted by the moving speed of the carriage.

  It should be noted that the ink ejection timing can be faithfully shifted by the obtained delay time ΔT by recreating the pixel data and further changing the generation timing of the drive pulse described above.

=== Other Embodiments ===
In the above-described embodiment, the printer 1 has been described as the fluid ejecting apparatus. However, the printer 1 is not limited to this, and is not limited to this. Other fluids other than ink (liquids, liquids in which particles of functional materials are dispersed, gels) Such a fluid can be embodied in a fluid ejecting apparatus that ejects or ejects the fluid. For example, color filter manufacturing apparatus, dyeing apparatus, fine processing apparatus, semiconductor manufacturing apparatus, surface processing apparatus, three-dimensional modeling machine, gas vaporizer, organic EL manufacturing apparatus (especially polymer EL manufacturing apparatus), display manufacturing apparatus, film formation You may apply the technique similar to the above-mentioned embodiment to the various apparatuses which applied inkjet technology, such as an apparatus and a DNA chip manufacturing apparatus. These methods and manufacturing methods are also within the scope of application.

  Further, the liquid ejecting apparatus is not limited to a liquid ejecting apparatus that causes pressure variation in the pressure chamber by the piezoelectric element, but may be a liquid ejecting apparatus tail that causes pressure variation in a certain force chamber by applying heat to the liquid. In these liquid ejecting apparatuses and the like, the drive signal generation circuit is not limited to the drive signal generation circuit including the DAC, and may be any drive circuit that generates a drive signal.

  The above-described embodiments are for facilitating the understanding of the present invention, and are not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof.

FIG. 1A is an external perspective view of the printer 1, and FIG. 1B is an internal perspective view of the printer 1. 2 is a block diagram of the printer 1. FIG. 3A is a view of the head 41 as viewed from below, and FIG. 3B is a cross-sectional view of the periphery of the nozzle row. It is a figure for demonstrating the delay time of a liquid injection. FIG. 5A is a graph showing the average ink speed with respect to the distance between the head and the medium, and FIG. 5B is a table showing the average ink speed with respect to the distance between the head and the medium. FIG. 6A is a graph showing the arrival time of ink with respect to the distance between the head and the medium, and FIG. 6B is a table showing the arrival time of ink with respect to the distance between the head and the medium. 6 is a graph showing the amount of landing deviation of ink with respect to the distance between the head and the medium. 6 is a flowchart for explaining an ink ejection timing delay process in the embodiment. FIG. 9A is a graph showing the average ink speed when the ink temperature change is considered, and FIG. 9B is a table showing the average ink speed when the ink temperature change is considered. FIG. 10A is a graph showing the ink arrival time when the temperature change is considered, and FIG. 10B is a table showing the ink arrival time when the temperature change is considered. FIG. 11A is a table showing a delay time for each size of ejected ink droplets, FIG. 11B is a table showing an average speed with respect to the platen gap PG for each size of ejected ink droplets, and FIG. It is a table which shows the arrival time with respect to the platen gap PG for every size of the ejected ink droplet. It is a figure for demonstrating the drive signal COM. It is a figure for demonstrating several drive signal COM1-COM4 produced | generated simultaneously. FIG. 3 is a diagram (part 1) for explaining an arrangement of dots indicated by pixel data. FIG. 5 is a diagram (No. 2) for explaining the arrangement of dots indicated by pixel data.

Explanation of symbols

1 printer,
20 paper transport mechanism, 30 carriage movement mechanism,
40 head units, 41 heads,
50 detector groups,
60 ASIC, 70 drive signal generation circuit,
CR carriage

Claims (8)

A head for ejecting fluid onto the medium;
A storage unit that stores the distance between the head and the medium and the flying speed of the fluid in association with each other;
A control unit that changes the ejection timing of the fluid from the head based on the flying speed obtained based on the distance;
A fluid ejection device comprising: And a moving mechanism for relatively moving the position of the head and the medium,
The fluid ejecting apparatus according to claim 1, wherein the control unit changes the ejection timing of the fluid from the head based on a relative moving speed between the head and the medium and the flying speed.   The fluid ejecting apparatus according to claim 1, wherein the flying speed is an average flying speed between the head and the medium.   The fluid ejecting apparatus according to claim 1, wherein the distance and the flying speed are associated with each other in a non-linear relationship and stored in the storage unit. The storage unit stores the distance and the flying speed for each dot size formed on the medium,
5. The fluid ejecting apparatus according to claim 1, wherein the control unit changes the ejection timing of the fluid based on the dot size and the flying speed obtained based on the distance.   The fluid ejecting apparatus according to claim 1, wherein the control unit further changes the ejection timing of the fluid based on the temperature of the fluid. A fluid ejection method comprising:
Determining the flying speed of the fluid based on the distance between the head and the medium;
Changing the ejection timing of the fluid from the head based on the determined flight speed, and ejecting the fluid;
A fluid ejection method comprising: A head for ejecting fluid to the medium;
A storage unit in which a distance between the head and the medium and a flight time of the fluid corresponding to the distance are associated and stored in a non-linear relationship;
A control unit that changes the timing of ejecting the fluid from the head based on the flight time of the fluid determined based on the distance;
A fluid ejection device comprising:

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