Patent Description:
There is an inkjet recording device that applies a pressure variation to ink supplied through an ink flow path (ink channel), in pressure chambers positioned at the middle of the ink channel, and discharges ink through multiple nozzles that communicate with the pressure chambers, thus recording an image, a thin film, wiring, a three-dimensional structure, etc..

The inkjet recording device drives an inkjet head while causing a carriage mounted with the inkjet head to perform scanning on a conveyance axis, thus discharging droplets of ink and forming an image on a recording medium. The drive cycle of the inkjet head is generated based on an output signal obtained from a linear encoder in synchronization with scanning by the carriage.

In relation to this, Patent Literature <NUM> describes an invention that dynamically changes the timing of pulses for driving a printing head, based on the speed and acceleration of the carriage.

Patent Literature <NUM> describes an inkjet recording device with a carriage, a setter and a detector.

As described above, based on the position information on the carriage, the drive cycle of the inkjet is determined. Accordingly, when the conveyance speed of the inkjet head is not a constant speed, the drive cycle and the drive frequency of the inkjet head vary. After droplets are discharged, reverberation occurs in a pressure chamber of the inkjet head, and affects droplets to be discharged next and thereafter. Consequently, when the drive frequency of the inkjet head varies, the affecting degree by the reverberant also varies. Accordingly, the droplet speed of ink also varies. There has been a problem that possible variation in ink droplet speed varies droplet landing positions, and shading unevenness occurs in a formed image.

<FIG> shows an example of the drive cycle of the inkjet head, and the droplet speed of ink when the conveyance speed of the inkjet head is not a constant speed. In the example shown in <FIG>, the abscissa axis indicates time (s) after start of driving the inkjet head, and the ordinate axis indicates the conveyance speed (m/s: solid line) of the inkjet head, and the drive cycle (µs: broken line) of the inkjet head, and the ink droplet speed (m/s: chain line) are shown. In a period in which driving of the inkjet head is started and the inkjet head is in acceleration, the drive cycle of the inkjet head gradually decreases. The ink droplet speed is unstable and periodically varies, and the amplitude gradually increases.

According to the invention according to Patent Literature <NUM>, variation in droplet landing position due to variation in drive frequency (cycle) of the inkjet head is not compensated, and the problem described above is not solved.

The present invention has an object to provide an inkjet recording device and a program that can achieve a more stable image quality in a formed image.

According to the present invention, in a formed image, a more stable image quality can be achieved.

Hereinafter, embodiments of the present invention are described with reference to the drawings.

An inkjet recording device <NUM> in this embodiment is, for example, an inkjet recording device that forms an image on a three-dimensional object or the like (recording medium), and includes a robot arm main body <NUM> that includes a carriage <NUM> mounted with inkjet heads <NUM> as shown in <FIG>.

<FIG> is a block diagram showing a functional configuration of the inkjet recording device <NUM> in this embodiment.

The inkjet recording device <NUM> includes a robot arm <NUM>, inkjet heads <NUM>, a drive waveform signal generator <NUM>, a controller <NUM>, a storage <NUM>, a communicator <NUM>, an operation acceptor <NUM>, a display <NUM>, and a power supplier <NUM>.

The robot arm <NUM> includes: the robot arm main body <NUM> that includes the carriage <NUM>; and a robot arm drive controller <NUM>.

The robot arm main body <NUM> is a <NUM>-axis articulated robot. For example, a recording medium is a three-dimensional object. It is configured that each inkjet head <NUM> can be arranged at a predetermined distance set with respect to an image formation surface of the recording medium even if the image formation surface is a curved surface. The robot arm main body <NUM> is not limited to a six-axis one. Alternatively, a multiple articulated robot that includes an appropriate number of axes, such as five axes or seven axes, may be adopted. Since a multiple robot itself is publicly known, the detailed description thereof is omitted.

The robot arm drive controller <NUM> applies drive control to the robot arm main body <NUM> under control by the controller <NUM>.

The robot arm drive controller <NUM> includes an encoder <NUM>. The encoder <NUM> detects the rotation of a drive motor of the robot arm drive controller <NUM>, and outputs a signal in accordance with the rotation direction at every rotation by a predetermined angle, thus detecting the position of the carriage <NUM>.

The inkjet head <NUM> discharges ink on a recording medium, and records an image or the like. Each inkjet head <NUM> includes a plurality of recording elements 20a, and a head driver <NUM>.

The recording elements 20a each include nozzles <NUM>, ink flow paths <NUM>, and piezoelectric elements <NUM>.

The head driver <NUM> applies a drive signal (drive waveform) to a selected piezoelectric element <NUM>, and causes the piezoelectric elements <NUM> to perform transforming operation.

Ink is sent from a supply path common to the nozzles <NUM> to the nozzles <NUM> via ink flow paths <NUM> communicating with the respective nozzles <NUM>. Each ink flow path <NUM> includes a pressure chamber. By transforming operation in accordance with application of a drive voltage to the piezoelectric elements <NUM> that are positioned along a wall surface of the pressure chamber (or are the wall surface itself), pressure variation is applied to ink in the pressure chamber. The piezoelectric elements <NUM> apply pressure variation in accordance with a drive waveform to ink supplied to the nozzles <NUM>, eject (discharge) ink droplets from the nozzles <NUM>, and record an image. The inkjet recording device <NUM> is provided with the inkjet heads <NUM> as many as the number of colors or types of ink ejected each time of image recording operation in the inkjet recording device <NUM>. Each inkjet head <NUM> can discharge ink according to a multi-drop scheme that sequentially discharges a plurality of ink droplets, combines them at the middle as a single droplet, and lands this droplet in a corresponding pixel region (an identical pixel region), and can define a shading graduation in each pixel region in accordance with the number of ink droplets.

The drive waveform signal generator <NUM> generates a drive waveform to be output by the head driver <NUM> to the recording elements 20a. Although not specifically limited, the drive waveform signal generator <NUM> analog-converts digital data indicating a predefined drive waveform, and outputs a signal with amplified voltage and current, as a drive waveform, to the head driver <NUM>. The generated drive waveform may include not only trapezoidal waves or rectangular waves for discharging ink, but also a drive waveform having a waveform that gradually changes in ink pressure (triangular waves or the like; the pulse width may be, for example, a half width (a width of a portion with <NUM>% or more of amplitude); a value other than <NUM>% may be adopted).

The controller <NUM> is a processor that includes a CPU <NUM> (Central Processing Unit) and a RAM <NUM> (Random Access Memory), and comprehensively controls various operations of the inkjet recording device <NUM>. The CPU <NUM> performs various operation processes, and executes a control operation. The RAM <NUM> provides the CPU <NUM> with a working memory space, and stores temporary data. The controller <NUM> controls output of the drive waveform pertaining to an ink discharge operation at each inkjet head <NUM> to the recording elements 20a, based on image data to be recorded and on setting data pertaining to image recording.

The controller <NUM> stores a carriage coordinates and carriage speed table or a carriage coordinates and carriage acceleration table, described later, in the storage <NUM>, thus setting at least one of the speed and the acceleration of the carriage <NUM>, for each position of the carriage <NUM>. In this case, the controller <NUM> functions as a setter.

The controller <NUM> obtains, from the storage <NUM>, a droplet speed and drive cycle characteristics table that is drive cycle dependency information on the droplet speed of ink discharged from the inkjet head <NUM>. In this case, the controller <NUM> functions as an obtainer.

The controller <NUM> corrects control parameters during discharge of ink from each inkjet head <NUM>, based on at least one of the speed and the acceleration of the carriage <NUM>, and on the drive cycle dependency information on the droplet speed. In this case, the controller <NUM> functions as a corrector.

Here, the control parameters include image data, a discharge signal, and a drive waveform.

The storage <NUM> stores the image data to be recorded, and stores various programs and the setting data. The storage <NUM> includes at least a nonvolatile memory, and may further include a volatile memory (RAM). The image data may be stored in the RAM. The nonvolatile memory is, for example, a flash memory or the like, and may alternatively or additionally include an HDD (Hard Disk Drive) or the like. Note that part of the storage <NUM> may be held by the inkjet heads <NUM> or the like. Parameter information unique to each inkjet head <NUM>, initial abnormal nozzle information and the like can be stored in a nonvolatile memory included in each inkjet head <NUM>. These pieces of information may be read by the controller <NUM> in initial setting or the like after the inkjet head <NUM> is attached to the inkjet recording device <NUM>, and integrally stored and managed in the storage <NUM> of the inkjet recording device <NUM>.

The storage <NUM> stores the waveform setting data <NUM>.

The waveform setting data <NUM> stores waveform pattern data of the drive waveform to be output to each recording element 20a. In particular, the waveform pattern data stored here includes information on the start timing of the drive waveform, the pulse width, and the voltage amplitude associated with each time of ink discharge in a case in which multiple times of ink discharge are sequentially performed. The information on the pulse width may be a parameter obtained from the nonvolatile memory included in the inkjet head <NUM>. These pieces may be digital data from which the drive waveform is generated by the drive waveform signal generator <NUM>.

The storage <NUM> stores the carriage coordinates and carriage speed table that indicates the correspondence relationship where the speed of the carriage <NUM> in the carriage coordinates indicating the predetermined position of the carriage <NUM> is preset. Instead of the carriage coordinates and carriage speed table, the carriage coordinates and carriage acceleration table indicating the correspondence relationship where the acceleration of the carriage <NUM> in the carriage coordinates is preset may be stored.

The storage <NUM> stores the droplet speed and drive cycle characteristics table where the correspondence relationship between the droplet speed of ink discharged by the inkjet head <NUM> and the drive cycle of the inkjet head <NUM> is calculated by simulation. Here, <FIG> shows an example of the drive cycle dependency of the ink droplet speed at the inkjet head <NUM>. As shown in <FIG>, if the drive cycle of the inkjet head <NUM> is relatively short (e.g., <NUM> to <NUM>), the ink droplet speed is unstable.

The communicator <NUM> controls execution of communication with external devices. For example, based on a communication standard, such as TCP/IP, the communicator <NUM> can be connected to an external computer, obtain job data including image data to be recorded, and output a status of the image recording operation based on the job data. The communicator <NUM> may be directly connected to a peripheral device by the USB (Universal Serial Bus) or the like, thus allowing data to be transmitted and received.

The operation acceptor <NUM> accepts an input operation by a user or the like, and outputs the accepted content, as an input signal, to the controller <NUM>. The operation acceptor <NUM> includes, for example, a touch panel, and press button switches. The touch panel is positioned to overlap a display screen of the display <NUM>, and may allow operation content to be indicated in synchronization with the display content on the display screen.

The display <NUM> displays a status, a selection menu and the like, for the user or the like. The display <NUM> includes, for example, the display screen, and indicators (lamps). The display <NUM> includes, for example, a liquid crystal display, and can display various characters and diagrams on the display screen in a dot matrix manner. The indicators are made up of, for example, LED lamps or the like, and may be used in a case of indicating presence or absence of power supply, presence or absence of operation abnormality or the like.

The power supplier <NUM> supplies power at a voltage in accordance with each component of the inkjet recording device <NUM>. A voltage in accordance with the peak voltage of each drive waveform is output to a drive board of the inkjet head <NUM>.

Next, a control parameter correction process in the inkjet head <NUM> of the inkjet recording device <NUM> in this embodiment is described. The controller <NUM> executes the control parameter correction process in this embodiment before image formation by the inkjet head <NUM>.

<FIG> is a flowchart showing the flow of the control parameter correction process.

First, the controller <NUM> obtains the carriage coordinates and carriage speed table from the storage <NUM> (Step S1).

Next, the controller <NUM> obtains the droplet speed and drive cycle characteristics table from the storage <NUM> (Step S2).

Next, the controller <NUM> calculates a carriage coordinates and droplet speed table indicating the correspondence relationship between the carriage coordinates and the ink droplet speed, from the carriage coordinates and carriage speed table obtained in Step S1 and the droplet speed and drive cycle characteristics table obtained in Step S2 (Step S3).

Next, the controller <NUM> calculates a shading density profile indicating the correspondence relationship between the carriage coordinates and the shading of an image to be formed as shown in <FIG>, based on the carriage coordinates and droplet speed table calculated in Step S3 (Step S4).

Next, the controller <NUM> calculates a shading correction profile shown in <FIG> for canceling out the shading unevenness of the shading density profile calculated in Step S4 (Step S5). Here, the example in <FIG> is in a case of what is called solid printing and is for discharge on every pixel.

Next, the controller <NUM> corrects the shading of the image data to be recorded (control parameters), based on the shading correction profile calculated in Step S5 (Step S6), and finishes the processing.

Here, the controller <NUM> may execute the control parameter correction process using the carriage coordinates and carriage acceleration table instead of the carriage coordinates and carriage speed table.

In the inkjet recording device <NUM> in this embodiment, the carriage <NUM> includes a detector 111a. The detector 111a is a sensor that detects at least one of the speed and the acceleration of the carriage <NUM>, and outputs a detected signal to the controller <NUM>. The detector 111a may be included in the inkjet head <NUM>. The detector 111a is included in the carriage <NUM> or the inkjet head <NUM> as described above. Accordingly, the speed and the acceleration of the inkjet head <NUM> can be more correctly detected than a case in which the detector 111a is included in a portion of the robot arm main body <NUM> other than the carriage <NUM>.

The other points of configuration are the same as those of the configuration in the first embodiment.

Next, a control parameter correction process in the inkjet head <NUM> of the inkjet recording device <NUM> in this embodiment is described. The controller <NUM> executes the control parameter correction process in this embodiment during image formation by the inkjet head <NUM>.

<FIG> is a flowchart showing the flow of a control parameter correction process according to this embodiment.

First, the controller <NUM> obtains current position information on the carriage <NUM>, from the encoder <NUM> (Step S11).

Next, the controller <NUM> obtains, from the detector 111a, the average VHN of the speed of the carriage <NUM> at the pixel corresponding to the current position of the carriage <NUM> obtained in Step S11 (Step S12). Here, the average of the speed of the carriage <NUM> at the pixel corresponding to the current position is the average of the speed when the inkjet head <NUM> passes from the (N-<NUM>)-th pixel where discharge has been performed to the N-th pixel where next discharge is to be performed, for example.

Next, the controller <NUM> calculates the drive cycle TN at the pixel (e.g., (N-<NUM>)-th pixel to N-th pixel) corresponding to the current position, based on the average VHN of the speed of the carriage <NUM> at the pixel corresponding to the current position obtained in Step S12, according to the following Expression (<NUM>) (Step S13).

Here, dN denotes the distance from the (N-<NUM>)-th pixel to the N-th pixel in input image data.

Next, the controller <NUM> obtains the droplet speed and drive cycle characteristics table from the storage <NUM> (Step S14).

Next, the controller <NUM> obtains the droplet speed DVN at the pixel corresponding to the current position, based on the drive cycle TN at the pixel corresponding to the current position calculated in Step S13, and the droplet speed and drive cycle characteristics table obtained in Step S14 (Step S15).

Next, the controller <NUM> calculates the droplet flight time tN at the pixel corresponding to the current position, based on the droplet speed DVN obtained in Step S15, and the distance Gap from the nozzle surface of the inkjet head <NUM> to the image formation surface of the recording medium, according to the following Expression (<NUM>) (Step S16).

Here, when the droplet flight time tN is calculated, the effect of air resistance to ink droplets may be considered.

Next, the controller <NUM> calculates the position at which an ink droplet is to land on the image formation surface, based on the droplet flight time tN calculated in Step S16 and the average VHN of the speed of the carriage <NUM> at the pixel corresponding to the current position, thus calculating the distance DN between adjacent dots at the pixel corresponding to the current position, according to the following Expression (<NUM>) (Step S17).

<FIG> shows an example of the variation in distance DN between adjacent dots. In the example shown in <FIG>, the abscissa axis indicates the position (mm) of the carriage <NUM>, and the ordinate axis indicates the variation (um) in distance DN between adjacent dots.

Next, the controller <NUM> calculates a shading correction value such that the distance DN between adjacent dots calculated in Step S17 can be equal to the distance dN from the (N-<NUM>)-th pixel to the N-th pixel in the input image data (a target value in a state without shading unevenness) (Step S18). Specifically, if the distance DN between adjacent dots is smaller than the distance dN, correction in a direction of reducing the shading is made. If it is greater, correction in a direction of increasing the shading is made.

Next, the controller <NUM> corrects the shading of the image data to be recorded (control parameter), based on the shading correction value calculated in Step S18 (Step S19), and finishes the processing.

Next, a modification example <NUM> of the second embodiment is described.

<FIG> is a flowchart showing the control parameter correction process in this modification example. The controller <NUM> executes the control parameter correction process in this modification example during image formation by the inkjet head <NUM>.

Hereinafter, the difference from the second embodiment is mainly described. The configuration of the inkjet recording device <NUM> in this modification example is the same as that of the inkjet recording device <NUM> in the second embodiment.

In the control parameter correction process in this modification example shown in <FIG>, first, the controller <NUM> executes Steps S21 to S27 similar to Steps S11 to S17 of the control parameter correction process in the second embodiment.

Next, the controller <NUM> executes correction of an ink discharge signal such that the distance DN between adjacent dots calculated in Step S27 can be equal to the distance dN from the (N-<NUM>)-th pixel to the N-th pixel in the input image data (the target value in the state without shading unevenness). Specifically, the controller <NUM> calculates the correction time period ΔtaN of the discharge signal so as to satisfy the following Expression (<NUM>), according to the following Expression (<NUM>) (Step S28). <MAT><MAT>.

Here, VHN·ΔtaN is the average VHN of the speed of the inkjet head <NUM> passing the N-th pixel at which next discharge is to be performed, and the amount of deviation of the droplet landing position due to signal correction in a case in which the inkjet head <NUM> is moving.

Next, the controller <NUM> corrects the discharge signal (control parameter), based on the correction time period ΔtaN of the discharge signal calculated in Step S28 (Step S29), and finishes the processing.

Here, <FIG> shows an example of the correction time period ΔtaN of the discharge signal. In the example shown in <FIG>, the abscissa axis indicates the position (mm) of the carriage <NUM>, and the ordinate axis indicates the correction time period ΔtaN (us) of the discharge signal.

In the example shown in <FIG> and <FIG>, if the variation in distance DN between adjacent dots is greater than the target value in the state without shading unevenness, the time period of applying the discharge signal is corrected to be minus (in a direction of increasing the drive frequency). If the variation in distance DN between adjacent dots is smaller, the time period of applying the discharge signal corrected to be plus (in a direction of reducing the drive frequency).

Here, the example in <FIG> and <FIG> is in a case of what is called solid printing and is for discharge on every pixel. In a case of intermittent discharge, the discharge is discontinuous unlike the case shown in <FIG> and <FIG> in which the discharge is continuous.

In this modification example described above, the controller <NUM> executes the control parameter correction process during image formation by the inkjet head <NUM>. However, there is no limitation to this. All the pixels may be corrected before image formation. In a case in which correction is performed during image formation, correction is performed with reference to the (N-<NUM>)-th pixel, based on the amount of deviation of the droplet landing positions from the (N-<NUM>)-th pixel to the N-th pixel. However, in a case in which all the pixels are corrected before image formation, for example, correction may be performed with reference to the <NUM>-th pixel, based on the amount of deviation of droplet landing position therefrom.

In the control parameter correction process in this modification example shown in <FIG>, first, the controller <NUM> executes Steps S31 to S35 similar to Steps S11 to S15 of the control parameter correction process in the second embodiment.

Next, the controller <NUM> selects waveform pattern data (control parameter) of the drive waveform to be output to each recording elements 20a, from the waveform setting data <NUM>, based on the droplet speed obtained in Step S35 (Step S36), and finishes the processing. Specifically, as shown in <FIG>, if the droplet speed is slower than the target value in the state without shading unevenness, the controller <NUM> selects a waveform A having a low voltage value. If the droplet speed is higher than the target value, the controller <NUM> selects a waveform C having a high voltage value. If the droplet speed is appropriate with respect to the target value, the controller <NUM> selects a waveform B having a voltage value between the values of the waveforms A and C.

As described above, by selecting the waveform pattern data of the drive waveform on the basis of the droplet speed, the deviation in the landing position before and after switching of the waveform pattern can be small.

In Step S36 in the control parameter correction process in the modification example <NUM> of the second embodiment described above, the voltage value of the drive waveform is changed by selecting the waveform pattern data of the drive waveform on the basis of the droplet speed. However, there is no limitation to this. The pulse width of the drive waveform or the slope time period may be changed. The shape of the waveform may be a complicated waveform that is not a waveform with a single pulse.

The number of waveform pattern data items of the drive waveform stored in the waveform setting data <NUM> is determined based on the maximum frequency of an image formation job, the transfer rate of input image data, the number of gradations of ink quantity.

In the control parameter correction process in this modification example shown in <FIG>, first, the controller <NUM> executes Steps S41 to S45 similar to Steps S11 to S15 of the control parameter correction process in the second embodiment.

Next, the controller <NUM> controls the robot arm drive controller <NUM>, based on the droplet speed obtained in Step S45, and changes at least one of the position and angle of the carriage <NUM> (Step S46), and finishes the processing. Specifically, if the droplet speed is lower than the target value in the state without shading unevenness (predetermined reference value), the controller <NUM> reduces the distance between the carriage <NUM> and the recording medium (control parameter). If the droplet speed is higher than the target value, the controller <NUM> increases the distance between the carriage <NUM> and the recording medium (control parameter).

If the droplet speed is lower than the target value, the controller <NUM> corrects the angle of the carriage <NUM> (control parameter) so as to make the droplet landing positions dense. If the droplet speed is higher than the target value, the controller <NUM> corrects the angle of the carriage <NUM> (control parameter) so as to make the droplet landing positions sparse.

Here, in the second embodiment and its modification examples, the controller <NUM> may obtain, from the detector 111a, the acceleration of the carriage <NUM> at the pixel corresponding to the current position of the carriage <NUM>, and execute the control parameter correction process, based on the acceleration of the carriage <NUM>.

As described above, the inkjet recording device <NUM> according to this embodiment includes: an inkjet head <NUM>; a carriage <NUM> mounted with the inkjet head <NUM>; a setter (controller <NUM>) that sets at least one of a speed and an acceleration of the carriage <NUM>, for each position of the carriage <NUM>; an obtainer (controller <NUM>) that obtains drive cycle dependency information on a droplet speed of ink discharged from the inkjet head <NUM>; and a corrector (controller <NUM>) that corrects a control parameter during discharge of ink from the inkjet head <NUM>, based on at least one of the speed and the acceleration of the carriage, and on the drive cycle dependency information on the droplet speed.

Consequently, in a formed image, a more stable image quality can be achieved.

The inkjet recording device <NUM> according to this embodiment includes: an inkjet head <NUM>; a carriage <NUM> mounted with the inkjet head <NUM>; a detector 111a that detects at least one of a speed and an acceleration of the carriage <NUM>, for each pixel of an image to be formed; an obtainer (controller <NUM>) that obtains drive cycle dependency information on a droplet speed of ink discharged from the inkjet head <NUM>; and a corrector (controller <NUM>) that corrects a control parameter during discharge of ink from the inkjet head <NUM>, based on at least one of the speed and the acceleration of the carriage <NUM>, and on the drive cycle dependency information on the droplet speed.

The inkjet recording device <NUM> according to this embodiment includes: an inkjet head <NUM>; a carriage <NUM> mounted with the inkjet head <NUM>; a setter (controller <NUM>) that sets at least one of a speed and an acceleration of the carriage, for each position of the carriage <NUM>; a detector 111a that detects at least one of the speed and the acceleration of the carriage <NUM>, for each pixel of an image to be formed; an obtainer (controller <NUM>) that obtains drive cycle dependency information on a droplet speed of ink discharged from the inkjet head <NUM>; and a corrector (controller <NUM>) that corrects a control parameter during discharge of ink from the inkjet head <NUM>, based on at least one of the speed and the acceleration of the carriage <NUM>, and on the drive cycle dependency information on the droplet speed.

The inkjet recording device <NUM> in this embodiment includes the detector 111a, in the inkjet head <NUM> or the carriage <NUM>.

Consequently, the speed and the acceleration of the inkjet head <NUM> can be more correctly detected than a case in which the detector 111a is included in a portion of the robot arm main body <NUM> other than the carriage <NUM>.

In the inkjet recording device <NUM> in this embodiment, when the speed of the carriage <NUM> is not a constant speed, the corrector corrects the control parameters.

Consequently, if the speed of the carriage <NUM> is not a constant speed, a more stable image quality in the formed image can be achieved.

The inkjet recording device <NUM> in this embodiment adopts a three-dimensional object as an image formation target.

Consequently, even if the recording medium is a three-dimensional object, a more stable image quality in the formed image can be achieved.

In the inkjet recording device <NUM> in this embodiment, the corrector corrects image data as the control parameter.

Consequently, by correcting the image data, a more stable image quality in the formed image can be achieved.

In the inkjet recording device <NUM> in this embodiment, the corrector corrects the discharge signal as the control parameter.

Consequently, by correcting the discharge signal, a more stable image quality in the formed image can be achieved.

In the inkjet recording device <NUM> in this embodiment, the corrector corrects the control parameter through selection of a drive waveform.

Consequently, by correction through selection of the drive waveform, a more stable image quality in the formed image can be achieved.

In the inkjet recording device <NUM> in this embodiment, the corrector corrects a distance between the inkjet head <NUM> and a recording medium, and an angle of the inkjet head <NUM> from the recording medium, as the control parameters.

Consequently, by correcting the distance and the angle of the inkjet head <NUM> with respect to the recording medium, a more stable image quality in the formed image can be achieved.

In the inkjet recording device <NUM> in this embodiment, the corrector corrects the distance between the inkjet head <NUM> and the recording medium in a widening direction when the droplet speed is higher than a predetermined reference value, and corrects the distance in a narrowing direction when the droplet speed is lower than the predetermined reference value.

Consequently, by correcting the distance of the inkjet head <NUM> with respect to the recording medium on the basis of the droplet speed, a more stable image quality in the formed image can be achieved.

In the inkjet recording device <NUM> in this embodiment, the corrector corrects the angle of the inkjet head <NUM> from the recording medium so that landing positions of droplets discharged from the inkjet head <NUM> can be sparse when the droplet speed is higher than the predetermined reference value, and corrects the angle so that the landing positions of droplets discharged from the inkjet head <NUM> can be dense when the droplet speed is lower than the predetermined reference value.

Consequently, by correcting the angle of the inkjet head <NUM> with respect to the recording medium on the basis of the droplet speed, a more stable image quality in the formed image can be achieved.

The inkjet recording device <NUM> in this embodiment includes the robot arm (robot arm main body <NUM>), and the robot arm includes the carriage <NUM>.

Consequently, the carriage <NUM> is thus included in the robot arm, and if the speed of the carriage <NUM> is not a constant speed, a more stable image quality in the formed image can be achieved.

Note that the present invention is not limited to the embodiments and their modification examples. Various changes can be made.

For example, in the embodiments and the modification examples described above, the inkjet recording device <NUM> includes the robot arm main body <NUM> mounted with the inkjet head <NUM>. However, there is no limitation to this. It may be configured to correct the control parameter during ink discharge from the inkjet head <NUM> in the case in which the inkjet head <NUM> is configured to be included in the carriage moving on a rail, and an image is formed when the carriage moving speed is not a constant speed.

In the embodiments and the modification examples described above, the examples of correction in the case in which the speed of the carriage is not a constant speed are described. However, there is no limitation to this. Correction may be performed when the speed of the carriage is a constant speed but the drive frequency of the inkjet head varies.

In the embodiments and the modification example described above, the speed and the acceleration of the carriage <NUM> are detected by the detector included in the inkjet head <NUM> or the carriage <NUM>. However, there is no limitation to this. Detection may be performed based on the output signal of the encoder <NUM> of the robot arm drive controller <NUM>.

The controller <NUM> may use, in a combined manner, the modes of correcting the control parameters of the inkjet head <NUM> during ink discharge in the control parameter correction process of the first and second embodiments described above.

The scope of the present invention includes the scope of the invention described in the claims.

Claim 1:
An inkjet recording device (<NUM>), comprising:
an inkjet head (<NUM>);
a carriage (<NUM>) mounted with the inkjet head (<NUM>);
at least one of a setter and a detector, wherein the inkjet recording device (<NUM>) is configured such that at least one of a speed and an acceleration of the carriage (<NUM>) is set by the setter for each position of the carriage (<NUM>) or detected by the detector for each pixel of an image to be formed;
an obtainer that is a controller (<NUM>) configured to obtain drive cycle dependency information on a droplet speed of ink discharged from the inkjet head (<NUM>) by obtaining a droplet speed and drive cycle characteristics table from a storage (<NUM>) of the inkjet recording device (<NUM>); and
a corrector that is configured to correct a control parameter during discharge of ink from the inkjet head (<NUM>), based on at least one of the speed and the acceleration of the carriage (<NUM>), and on the drive cycle dependency information on the droplet speed.