JPH11300964A - Method for adjusting driving of ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure constant jet speed and volume of ink liquid droplets even with respect to any ink jet head even if control is not performed based on a severe common difference in a production process. SOLUTION: In a first process, the first data related to the jet speed of ink liquid droplets and the second data related to the volume of ink liquid droplets are measured at every ink jet head and, in a second process, the drive voltage becoming a proper jet speed and volume is determined on the basis of the regions A-D corresponding to the first and second data in a map 71 wherein a jet speed and volume and set to parameters and the voltage value is stored in a memory means at every ink jet head. By this constitution, recording of constant recording quality is enabled in any ink jet head.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a driving adjustment method for an ink jet head.

[0002]

2. Description of the Related Art Conventionally, as an ink jet type ink ejecting apparatus, the volume of an ink chamber is changed by deformation of piezoelectric ceramics, and when the volume is reduced, ink in the ink chamber is ejected from a nozzle as ink droplets to increase the volume. There has been known an ink jet printer which sometimes introduces ink into an ink chamber through an ink inlet. In this type of ink jet head, a plurality of ink chambers separated by piezoelectric ceramic partitions are formed, and one end of each of the plurality of ink chambers is connected to an ink supply means such as an ink cartridge, and the other end is provided with an ink supply. Injection nozzle (hereinafter,
A nozzle is simply provided), and by reducing the volume of the ink chamber by deformation of the partition wall according to a drive signal, ink droplets are ejected from the nozzle to a recording medium, and characters and graphics are recorded. You.

[0003]

However, with such a structure, the ink chamber of the ink jet head,
If the dimensions of the nozzles vary, even if the inkjet head is driven at a specified drive voltage, the ejection speed and volume of the ink droplets vary for each inkjet. When the ejection speed fluctuates, the ink jet head ejects ink droplets while reciprocating along the recording medium.
The position where the ink droplets adhere to the recording medium, that is, the landing position, is shifted between the forward movement and the backward movement. In an apparatus having a plurality of heads as in multicolor printing, the landing positions of ink droplets of each color are shifted, and high-quality printing cannot be performed. Further, when the volume of the ink droplet fluctuates, the dot diameter on the recording medium becomes large or too small, and the density in a predetermined area composed of a plurality of dots varies. Particularly, in the case of multi-color recording, there is a problem that the density balance of each color is out of order.

Therefore, it is necessary to control the dimensions of the ink chambers, nozzles, and the like in the manufacturing process with strict tolerances in order to ensure constant recording quality, which is the same in any ink jet head.

Incidentally, for example, Japanese Patent Application Laid-Open No. 5-185589
As described in Japanese Patent Application Laid-Open Publication No. H10-207, in a device that supplies a drive signal from a drive circuit to an actuator to generate a pressure wave and ejects ink in an ink chamber toward a recording medium,
A potentiometer having a variable resistance is inserted into the drive circuit, and the value of the potentiometer is adjusted so that ink droplets are ejected at a desired speed. After that, there has been proposed an ink droplet ejection speed adjusting method of removing the potentiometer and adjusting the value of the resistance means in the drive circuit by laser trimming based on the adjusted value of the potentiometer. However, in such a method, it is necessary to adjust the value of the potentiometer and the value of the resistance means in the drive circuit so that the ink droplets are ejected at a desired speed, and this operation requires an extremely long time. And low efficiency. In addition, no consideration is given to the volume of ink droplets that affect the recording quality, and it is not sufficient to ensure a predetermined recording quality stably.

Further, as described in JP-A-7-32651, a plurality of groups of test images are recorded, the density of the test images is measured by an optical scanner, and the difference between the measured density and the control value is measured. Is determined. In addition, there has been proposed a method for optimizing the characteristics of an ink jet head that calculates an optimum value of each drive control value from a characteristic curve, a test result, a test control value, and a desired color density. Calculating the optimal value of the drive control value using the above characteristic optimization method is as follows.
It requires many man-hours and is inferior in mass productivity.

Further, the use of both the former adjustment method and the latter characteristic optimization method makes the efficiency even worse.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a drive adjustment method of an ink-jet head which can ensure a constant recording quality for any ink-jet head without managing with tight tolerances. It is intended to do so.

[0009]

According to the first aspect of the present invention, there is provided a method for adjusting the drive of an ink-jet head for ejecting ink droplets from nozzles from an ink chamber filled with ink by applying an ejection signal to an actuator. For each inkjet head, the first information about the ejection speed of the ink droplet and the second information about the volume of the ink droplet
And a second step of determining a drive voltage to be applied to the inkjet head based on the first and second information.

According to the first aspect of the present invention, in the first step, first information about the ejection speed of ink droplets and second information about the volume of ink droplets are provided for each ink jet head. Are measured. Then the second
In the step of, based on the first and second information,
The drive voltage applied to the inkjet head is determined. As a result, variations in the volume and ejection speed of ink droplets due to variations in the dimensions of the ink chambers and nozzles of the inkjet head are canceled, and a constant volume and ejection speed of the ink droplets are obtained in each inkjet head, and recording quality is improved. Are equalized.

According to a second aspect of the present invention, in the driving adjustment method for an ink jet head according to the first aspect, in the second step, the driving voltage is reduced as the ejection speed of the ink droplet is increased, and the volume of the ink droplet is reduced. The larger the value, the smaller the drive voltage.

According to the second aspect of the present invention, the drive voltage applied to the ink jet head is adjusted to be smaller as the ejection speed of the ink droplet is higher and as the volume of the ink droplet is larger.

According to a third aspect of the present invention, in the driving adjustment method of the ink jet head according to the first or second aspect, in the second step, a map is used in which the ejection speed of the ink droplet and the volume of the ink droplet are used as parameters. It is created and the drive voltage is determined based on the map. In this case, the map includes one configured as a program or a table for calculating an appropriate drive voltage by inputting the injection speed and the volume.

According to the third aspect, the ejection speed of the ink droplet and the volume of the ink droplet are used as parameters based on the ejection speed of the ink droplet and the volume of the ink droplet measured in the first step. The drive voltage is determined based on the map. Therefore, the drive voltage to be applied to the inkjet head is determined easily and easily.

According to a fourth aspect of the present invention, in the method for adjusting the drive of an ink-jet head according to any one of the first to third aspects, in the first step, the ink-jet head comprises:
While moving along the recording medium at a predetermined interval from the recording medium, the jetting speed of the ink droplets is measured from the deviation amount of the recording position at the time of recording.

According to the fourth aspect of the present invention, the recording is performed on the recording medium while the ink jet head is moved along the recording medium at a predetermined interval from the recording medium. Since the recording position (for example, a dot row) recorded on the recording medium is determined by the moving speed of the ink jet head and the ejection speed of the ink droplet, the ejection speed of the ink droplet is measured from the displacement amount of the recording position. You. This is because if the moving speed of the carriage is kept constant, the ink droplet ejection speed is recorded at a predetermined position if the ejection speed matches the target speed, whereas if not, the ink droplet ejection speed is recorded at the predetermined position. On the other hand, the recording position is shifted in any direction, and the larger the degree of the shift, the greater the speed difference from the target speed.

According to a fifth aspect of the present invention, in the driving adjustment method for an ink-jet head according to any one of the first to fourth aspects, in the first step, a plurality of dots formed by recording the volume of the ink droplet on a recording medium is provided. Is measured in a predetermined range of recording density.

According to the fifth aspect of the present invention, the volume of the ink droplet is measured based on a predetermined range of recording density of a plurality of dots recorded on the recording medium. This utilizes the fact that the larger the volume of the ink droplet, the higher the recording density, and the smaller the volume of the ink droplet, the lower the recording density.

According to a sixth aspect of the present invention, in the driving adjustment method for an ink-jet head according to any one of the first to third aspects, in the first step, the ejected ink droplets are imaged, and the ink droplets are taken from the imaged image. It measures the injection speed and volume of the sample.

According to the present invention, the ejected ink droplet is imaged, and the ejection speed and volume of the ink droplet are measured from the imaged image.

According to a seventh aspect of the present invention, in the method for adjusting the drive of an ink jet head according to any one of the first to sixth aspects, the memory means provided integrally with the ink jet head comprises:
The method further includes a third step of storing data corresponding to the voltage value determined in the second step.

According to the seventh aspect of the invention, in the third step following the second step, data corresponding to the voltage value determined in the second step is stored in the memory means provided integrally with the ink jet head. Is done. Therefore, the drive voltage (second voltage) stored in the memory means is applied to the inkjet head.
The data corresponding to the voltage value determined in the step is applied, and the inkjet head is driven at a different drive voltage. As a result, the recording quality does not vary from one inkjet head to another, and a constant recording quality is ensured in any of the inkjet heads.

According to an eighth aspect of the present invention, in the method for adjusting the drive of an ink jet head according to any one of the first to seventh aspects, there is a plurality of the ink jet heads, and the adjustment is performed for each ink jet head.

According to the eighth aspect of the present invention, the adjustment is performed for each of the plurality of ink jet heads, and the drive voltage is determined for each. Therefore, in multi-color recording or the like, the recording quality of each head is equalized, and high-quality recording can be achieved.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a main part of an ink jet recording apparatus using an ink jet head according to the present invention. In FIG. 1, an ink jet head 1 that performs recording by ejecting ink droplets onto a recording medium (not shown) is configured to be supplied with ink from an ink cartridge 2 that stores the ink.

The ink jet head 1 has a plurality of ink chambers 26 to be described later, and a manifold 6 is connected to a rear end thereof. The ink supply port 5 of the manifold 6 is
It is connected to the ink outlet 2 a of the ink cartridge 2 via the joint members 8 and 9. Filters 7 and 10 are provided between the ink supply port 5 and the joint member 8, and between the joint member 9 and the ink outlet 2a. The ink in the ink cartridge 2 is distributed to each ink chamber 26 by the manifold 6.

The ink-jet head 1 is fixedly supported by the holder member 3 together with the manifold 6.
Is detachably mounted on a known carriage (not shown) provided to be reciprocally movable in the width direction of the recording medium.
Further, a memory means 11 (ROM) for storing data corresponding to a voltage value determined in a second step described later is provided on the bottom wall 3b of the holder member 3, whereby data unique to the inkjet head 1 is provided. Is mounted on a carriage integrally with the inkjet head 1. Therefore, when the inkjet head 1 is set in the inkjet recording apparatus, the control unit of the recording apparatus reads out this data,
An optimal voltage value (driving voltage) for ensuring the target recording quality is output, and the driving of the inkjet head 1 is controlled. Note that an upper cover 12 and a lower cover 13 are provided above and below the inkjet head 1 and the manifold member 6, respectively.
Is provided.

As shown in FIG. 2, the ink jet head 1 has an adhesive 3 with a pair of actuator substrates 21 and 21 sandwiching a plate member 22 therebetween.
6 and 36 (see FIG. 3), an actuator member 23 formed by joining
And a nozzle plate 24 joined to the front end face of the nozzle plate with an adhesive. The manifold 6 for supplying ink is joined to the rear end face of the actuator member 23.

As shown in FIG. 3, each of the actuator substrates 21 is formed by laminating piezoelectric material layers 21A and 21B made of a lead zirconate titanate (PZT) ceramic material via an adhesive layer 21C. The piezoelectric material layers 21A and 21B are polarized in directions opposite to each other (each in the thickness direction of the actuator substrate 21).
On the surface 21a of the actuator substrate 21, a plurality of ink chambers 26,... And dummy spaces 27,. Ink chamber 2
6 penetrates the front and rear end surfaces of the actuator substrate 21, but the dummy space 27 is closed to the manifold 6 near the rear end surface 21 d of the actuator substrate 21. The nozzle plate 24 has a nozzle 24 a opened at a position corresponding to the ink chamber 26.

Electrodes 31, 33 are formed on the inner surfaces of each ink chamber 26 and the dummy space 27, and the electrodes 33, 33 on both side surfaces of the dummy space 27 are mutually independent by a groove 32a. A pair of partition walls 28 and 2 sandwiching one ink chamber 26
8 and a pair of electrodes 31 and 33 formed on both side surfaces thereof constitute a set of actuators. The pair of partition walls 28, 2
While applying a drive voltage to the electrodes 33, 33 outside the
Electrode 3 inside ink chamber 26 between a pair of partition walls 28
By grounding 1, 1 and 31, an electric field in a direction perpendicular to the polarization direction of the piezoelectric material is generated inside the partition, and the partition 2
8, 28 are deformed in the direction in which the volume of the ink chamber 26 changes, as indicated by the dashed line in FIG. 3, so that the ink in the ink chamber 26 is ejected from the nozzle 24a. Here, the deformation direction of the partition walls 28, 28 returns to the direction in which the volume of the ink chamber 26 decreases after being deformed in the direction of increasing the volume of the ink chamber 26, or after the deformation in the direction in which the volume of the ink chamber 26 decreases. Or return.

As described above, if a constant driving voltage is applied to the ink jet head 1, a constant ejection speed and a constant volume of ink droplets should be obtained by any of the ink jet heads 1. Even if a constant driving voltage is applied to the ink jet head 1 that varies in size due to variations in the size of the ink chamber 26 and the nozzles 24a of the ink jet head 1 due to manufacturing, the ejection speed and volume of ink droplets , The recording quality cannot be ensured.

Then, subsequently, the ink jet head 1
A method for adjusting the drive of the inkjet head 1 according to the present invention, which can correct the influence of fluctuations in the ejection speed and volume of ink droplets due to variations in the dimensions of the ink chamber 26 and the nozzles 24a. (First Step) First, for each inkjet head 1,
First information about the ejection speed of the ink droplet and second information about the volume of the ink droplet are measured.

Here, as shown in FIG. 4, for example, the ejection speed of the ink droplets as the first information is determined by mounting the ink jet head 1 on the carriage 51 and leaving the recording medium 52 at a predetermined distance from the recording medium 52. While moving along 52
The ejection speed of the ink droplet is measured from the displacement amount of the landing position when the ink droplet is ejected. Here, as the carriage 51, a carriage as a part of a test apparatus can be used, or a carriage of an ink jet recording apparatus to which an ink jet head is attached can be used.

Specifically, as shown in FIG. 4A, when the carriage 51 is reciprocated at a constant speed, and the ink is ejected at a predetermined reference ejection speed, the ink lands on the recording medium 52. The carriage positions P1 and P2 whose positions match as shown by the solid line in FIG. 4 are set. Then, while actually moving the inkjet head 1, the position P
When the ejection is performed at P1 and P2, the ink is ejected in the direction indicated by the broken line A if the ejection speed is higher than the target reference ejection speed, and the ink is ejected in the direction indicated by the broken line B if the ejection speed is slower. The shift amounts S1 and S2 occur in FIG.
(See (b) and (c)). By these shift amounts S1 and S2,
The difference between the actual ink ejection speed and the set ejection speed is determined. The displacement of the landing position occurs because the direction in which the ink is ejected is the direction of the vector sum of the moving speed of the carriage 51 and the ink ejecting speed. By making it constant, the influence of the moving speed of the carriage 51 on the ink ejection direction can be eliminated, and the ink ejection speed can be measured.

On the other hand, the volume of the ink droplet, which is the second information, is measured by a recording density in a predetermined range composed of a plurality of dots recorded on the recording medium.

Specifically, the drive voltage is adjusted so that the ejection speed of the ink droplets ejected from the ink jet head becomes a predetermined reference ejection speed, and the recording is performed on the recording medium by the ink droplets at the reference ejection speed. As shown in FIG. 5, the density of the predetermined image in the predetermined image is measured using an optical reflection density measuring device. If the volume of the ink droplet is large, the dot diameter on the recording medium is large, and the density is high.If the volume is small, the dot diameter is small and the density is low. The volume can be determined.

Further, as a method of measuring the first information and the second information, as shown in FIG. 6, an image of an ink droplet 61 ejected from an ink jet head is taken by a CCD camera 62 and the image is monitored. 63, and the time required to move between the positions P11 and P12 is determined.
1 and the image 6 of the projected ink droplet.
By determining the size of 1A, the volume of each of the ink droplets can be measured. (Second Step) A drive voltage to be applied to the inkjet head 1 is determined based on the first and second information.

In this case, if the ejection speed of the ink droplets is higher than the reference ejection speed, the driving voltage is decreased, and if the ejection speed is slower, the driving voltage is increased. Then, the drive voltage is determined so as to be higher if it is smaller. By determining the drive voltage in this manner, the drive voltage approaches the target ejection speed and volume of the ink droplet.

Specifically, as shown in FIG. 7, a map 71 is prepared in which the ejection speed of the ink droplet and the volume of the ink droplet are used as parameters. In the map, the injection speed is set on the vertical axis and the volume is set on the horizontal axis, and the map is divided into a plurality of stages, and a voltage that provides an appropriate injection speed and volume is set for each region of the matrix composed of both axes. In this matrix, if the ejection speed of the ink droplet is higher than the reference ejection speed, the driving voltage is decreased, and if the ejection speed is lower, the driving voltage is decreased. The drive voltage is set so as to be higher if it is smaller.

That is, the measured ink droplet ejection speed and ink droplet volume are determined by any of the areas A to
D, the driving voltage applied to the inkjet head 1 (18V, 20V in this example)
V, 22V). By using the map 71 in this way, a drive voltage that provides an appropriate ejection speed and volume is immediately determined from the measured ejection speed and volume of the ink droplet.

Here, the map 71 has four regions, but is not limited thereto, and various changes can be made. For example, a map in which the ejection speed of the ink droplets and the volume of the ink droplets are divided into nine regions by dividing into three stages, or a map divided into sixteen regions by dividing into four stages can be used. . In addition, the step of partitioning the ejection speed of the ink droplet and the volume of the ink droplet need not be the same stage. For example, the ejection speed of the ink droplet is two stages, and the volume of the ink droplet is three stages. A map divided into six areas by partitioning, a three-step ink droplet ejection speed and a four-step ink droplet volume
It is also possible to use a map divided into regions. (Third Step) Data corresponding to the drive voltage value determined in the second step is stored in the memory means 11 provided integrally with the holder member 3 supporting the ink jet head 1. That is, for each inkjet head 1, the first
The different driving voltages (voltage values) determined through the steps (1) and (2) are stored as data. Here, it is possible to adopt a configuration in which the injection speed and the volume are input, data corresponding to an appropriate voltage value is calculated, and the calculated data is written in the memory means 11. In this case, in the second step, the map is configured as a program or a table for performing the above calculation in the device.

With this arrangement, in the recording apparatus, when the carriage is reciprocated to eject ink droplets on the recording medium, the driving is controlled with the optimal driving voltage for each ink jet head 1. Even in the case of the ink jet head described above, a substantially constant ink droplet volume and ejection speed are ensured.

Therefore, in a recording apparatus equipped with a single ink jet head, when the ink jet head ejects ink droplets while reciprocating, the landing positions of the forward movement and the backward movement are almost the same, and each recording apparatus has The recording densities also become almost the same. When a plurality of inkjet heads are provided as in a multi-color recording apparatus, the adjustment is performed for each inkjet head as described above, and an appropriate drive voltage is stored in the memory unit. As a result, the landing positions of the respective colors substantially coincide with each other, and the density balance of the respective colors is maintained almost accurately.

In short, even if there are variations in the dimensions of the ink chambers and nozzles of the ink jet head 1, by determining the drive voltage as described above, the variation in the dimensions of the ink chambers and nozzles affects the recording quality. Can be canceled, so that it is not necessary to manage with tight tolerances in the manufacturing process of the inkjet head 1,
Also, the yield is improved.

In the above description, one embodiment of the present invention has been described. However, the present invention is not limited to the embodiment, and various changes can be made. For example, the present invention can be applied to any inkjet head that ejects ink droplets from nozzles from an ink chamber filled with ink by applying an ejection signal to an actuator. For example, a heating resistor ( The present invention can also be applied to a so-called bubble jet type ink jet head which instantaneously gives the heat generated by zirconium boride, causes film boiling, and ejects ink by utilizing the volume expansion of the boiling bubbles.

[0047]

The present invention is embodied in the form described above, and has the following effects.

According to a first aspect of the present invention, in the first step,
For each ink jet head, first information about the ejection speed of the ink droplet and second information about the volume of the ink droplet are measured, and in the second step, the first and second information are measured. Since the drive voltage to be applied to the inkjet heads is determined on the basis of the above, it is possible to determine the optimal drive voltage for each inkjet head, and to reduce the variation in recording quality between the inkjet heads. Even with an ink jet head, it is possible to perform recording with a constant quality. Therefore, in the manufacturing process of the ink-jet head, it is not necessary to manage with a tight tolerance, and the yield is improved.

According to a second aspect of the present invention, the driving voltage applied to the ink jet head is
The lower the ejection speed of the ink droplets and the smaller the volume of the ink droplets, the smaller the ejection speed. Becomes possible.

According to a third aspect of the present invention, a drive voltage to be applied to an ink jet head is determined based on a map using the ink droplet ejection speed measured in the first step and the volume thereof as a parameter. Therefore, the driving voltage can be determined easily and in a short time for each ink jet head, and the mass productivity can be improved.

According to a fourth aspect of the present invention, while the ink jet head is moved along the recording medium at a predetermined interval from the recording medium, the recording is performed on the recording medium, and the displacement of the recording position recorded on the recording medium is determined. Since the jetting speed of the ink droplets is measured from, the jetting speed of the ink droplets can be easily measured.

According to a fifth aspect of the present invention, the volume of the ink droplet is
Since the measurement is performed based on the recording density within a predetermined range including a plurality of dots recorded on the recording medium, the volume of the ink droplet can be easily measured.

According to the sixth aspect of the present invention, since the ejected ink droplets are imaged and the ejection speed and volume of the ink droplets are measured from the captured image, both can be measured in a short time.

According to a seventh aspect of the present invention, the third step following the second step is performed.
In the step, data corresponding to the voltage value determined in the second step is stored in the memory means provided integrally with the ink jet head. Driving with a voltage can ensure a certain recording quality.

According to the eighth aspect of the present invention, in the case where a plurality of ink jet heads are provided, the adjustment is performed for each ink jet head. Can be.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an ink jet recording apparatus using an ink jet head according to the present invention.

FIG. 2 is an exploded perspective view of the inkjet head according to the present invention.

FIG. 3 is an explanatory diagram of an operation of the inkjet head according to the present invention.

FIG. 4 is an explanatory diagram of a method for measuring the ejection speed of ink droplets according to the present invention.

FIG. 5 is an explanatory diagram of a method for measuring the recording density of ink droplets according to the present invention.

FIG. 6 is an explanatory diagram of another measurement method of an ink droplet ejection speed and a recording density.

FIG. 7 is an explanatory diagram of a map according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink jet head 2 Ink cartridge 11 Memory means 24a Nozzle 26 Ink chamber 61 Ink droplet

Claims (8)

[Claims] An ink jet head drive adjustment method for ejecting ink droplets from nozzles from an ink chamber filled with ink by applying an ejection signal to an actuator, comprising the steps of: A first step of measuring first information about the ejection speed and second information about the volume of the ink droplet; and a driving voltage applied to the inkjet head based on the first and second information. A driving adjustment method for an ink jet head. 2. The ink-jet head according to claim 1, wherein in the second step, the driving voltage is reduced as the ejection speed of the ink droplet is increased, and the driving voltage is decreased as the volume of the ink droplet is increased. Drive adjustment method. 3. The method according to claim 1, wherein, in the second step, a map is created using the ejection speed of the ink droplet and the volume of the ink droplet as parameters, and the driving voltage is determined based on the map. The driving adjustment method of the ink jet head described in the above. 4. In the first step, while moving the ink jet head along a recording medium at a predetermined interval from the recording medium, ejecting ink droplets from a shift amount of a recording position at the time of recording. The method for adjusting the drive of an ink-jet head according to any one of claims 1 to 3, wherein the speed is measured. 5. The method according to claim 1, wherein in the first step, the volume of the ink droplet is measured based on a predetermined range of recording density of a plurality of dots recorded on a recording medium. A method for adjusting the drive of an ink-jet head according to any one of the above. 6. The method according to claim 1, wherein in the first step, the ejected ink droplet is imaged, and the ejection speed and volume of the ink droplet are measured from the imaged image.
4. The method for adjusting the drive of an inkjet head according to any one of 3. 7. The method according to claim 1, further comprising a third step of storing data corresponding to the voltage value determined in said second step in a memory means provided integrally with said ink jet head. A method for adjusting the drive of an ink-jet head according to any one of the above. 8. The drive adjustment method for an ink-jet head according to claim 1, wherein a plurality of the ink-jet heads are provided, and the adjustment is performed for each of the ink-jet heads.