JP4595463B2 - Inkjet printer - Google Patents

Description

  The present invention relates to an ink jet printer that discharges and records ink on a printing medium.

  Ink jet printers record on paper or the like by ejecting ink onto the paper or the like from a plurality of nozzles arranged in a predetermined direction. Here, if the flying direction of the ink ejected from a plurality of nozzles is tilted in a certain direction due to a nozzle processing error or the like, and the ink landing position is deviated from the normal position (the position immediately below the nozzle), the adjacent 2 The ink ejected from each of the nozzles is separated and landed to form two dots with a gap between them, resulting in white streaks extending in a direction perpendicular to the nozzle arrangement direction, resulting in a decrease in print quality. However, in order to reduce the deviation of the ink landing position, it is necessary to manage the processing accuracy of the nozzles very strictly, which increases the manufacturing cost of the ink jet head. In view of this, there has been proposed an ink jet printer capable of adjusting the deviation of the landing positions of ink ejected from the nozzles after the ink jet head is assembled.

  For example, the ink jet printer described in Patent Document 1 has a plurality of heads having a plurality of nozzles arranged in a predetermined direction, and each head has an attachment angle (inclination of the nozzle row with respect to the paper feeding direction). ) Is changed by an eccentric screw and a spring so that white streaks are not generated, and the interval between adjacent nozzle rows can be adjusted. Furthermore, the ejection timing from the nozzles can be adjusted according to the amount of deviation of the landing position of the ink ejected from each nozzle.

JP 2003-145777 A

  However, in the ink jet printer described in Patent Document 1, it is necessary to adjust the mounting angle of each of the plurality of heads and further to adjust the discharge timing from each nozzle. It takes time. Further, since a mechanism (such as an eccentric screw or a spring) for adjusting the mounting angle is required for each of the plurality of heads, the number of parts increases, which is disadvantageous in terms of manufacturing cost.

  An object of the present invention is to provide an ink jet printer that can easily correct a deviation in landing positions of ink from a plurality of nozzles.

Means for Solving the Problems and Effects of the Invention

The ink jet printer according to the first aspect of the present invention is provided with a plurality of nozzles arranged in a predetermined direction and corresponding to each of the plurality of nozzles, and applies an ejection pressure for ejecting ink from the corresponding nozzles to the ink. An ink jet head having a plurality of ink discharge pressure applying means, a drive signal generating means for generating a drive signal supplied to the plurality of ink discharge pressure applying means, and a substrate to be printed relative to the ink jet head; A feeding means for moving, a head driving means for moving the ink jet head in the predetermined direction, and a discharge pressure applied to the ink by the plurality of ink discharge pressure applying means while moving the ink jet head in the predetermined direction by the head driving means. And discharging ink from the plurality of nozzles at a predetermined discharge timing, respectively. And a head control unit, the inkjet head, the predetermined direction is a direction of arrangement of said plurality of nozzles, the feeding means and the perpendicular to the feeding direction of the printing material by a head of the line type, wherein The head control means corresponds to a deviation amount of the ink landing position in the predetermined direction when ink is ejected from the corresponding nozzle to each of the plurality of ink ejection pressure applying means from the drive signal generating means. The drive signal is supplied.

  This ink jet printer supplies a drive signal from the drive signal generating means to a plurality of ink discharge pressure applying means while moving the printing medium relative to the ink jet head in a predetermined feed direction by the feed means, and By applying a discharge pressure to the ink by the discharge pressure applying means, the ink is discharged from the plurality of nozzles to the printing medium. Here, the ink jet head is configured to be driven in a predetermined direction, which is an arrangement direction of a plurality of nozzles, by the head driving means, and the head control means moves the ink jet head in the predetermined direction by the head driving means. Ink is ejected from the plurality of nozzles by the plurality of ink ejection pressure applying means.

Here, with respect to the arrangement direction of the nozzles from the normal landing position (the landing position when the ink flies in the axial direction of the nozzle) when the ink is ejected from a certain nozzle while the inkjet head is stationary. A drive signal corresponding to the amount of landing position deviation is supplied from the drive signal generating means to the ink discharge pressure applying means corresponding to the nozzle. Therefore, even when the landing position of the ink ejected from a certain nozzle shifts in the nozzle arrangement direction due to a nozzle processing error or the like, while moving the inkjet head in the nozzle arrangement direction by the head driving means, A drive signal corresponding to the amount of deviation of the landing position can be supplied to the ink discharge pressure applying means, and ink can be discharged from this nozzle at an appropriate discharge timing. Therefore, it is possible to easily correct the deviation of the landing position without performing complicated work. In addition, in the line type head, when the ink landing position from a certain nozzle is shifted in the nozzle arrangement direction, white streaks parallel to the feeding direction of the printing medium are generated, and the print quality is deteriorated. According to the present invention, it is possible to correct the deviation of the landing position in the nozzle arrangement direction, and thus it is possible to improve the print quality by preventing the occurrence of white streaks. In addition, since the deviation of the landing position can be corrected after the ink jet head is assembled in this manner, the processing accuracy of the nozzle required in the manufacturing stage of the ink jet head can be relaxed compared to the conventional case, and the manufacturing cost can be reduced. In the first invention and the following second to eighth inventions, the drive signal generating means may be included in the ink jet head as long as it generates a drive signal, and is included in the ink jet head. It may be a different configuration.

The ink jet printer according to a second aspect is the ink jet printer according to the first aspect , wherein the head control means intermittently performs the printing every time one ink ejection operation by the plurality of nozzles arranged in the predetermined direction is completed. The feeding means is controlled to feed the body. In this way, the landing position in the feeding direction of the printing medium between the plurality of nozzles arranged in a predetermined direction by feeding the printing medium every time one ink ejection operation is performed from the plurality of nozzles. Can be minimized.

An ink jet printer according to a third aspect of the invention is provided with a plurality of nozzles arranged in a predetermined direction and corresponding to each of the plurality of nozzles, and applies an ejection pressure for ejecting ink from the corresponding nozzles to the ink. An inkjet head having a plurality of ink discharge pressure applying means, a drive signal generating means for generating a drive signal supplied to the plurality of ink discharge pressure applying means, and a substrate to be printed moved relative to the ink jet head A feeding means for moving the ink jet head in the predetermined direction; a head driving means for moving the ink jet head in the predetermined direction; The ink is ejected from the plurality of nozzles at a predetermined ejection timing. Comprising a de control means, a carriage for holding said ink-jet head and said head drive means, and a carriage drive means for reciprocating drive of the carriage in a direction perpendicular to the feeding direction of the printing material by the feeding means, the ink-jet The head is arranged so that the predetermined direction, which is an arrangement direction of the plurality of nozzles, is parallel to the feed direction, and the head control unit applies the plurality of ink discharge pressures from the drive signal generation unit. Each of the means is supplied with the drive signal corresponding to the deviation amount of the landing position of the ink in the predetermined direction when the ink is ejected from the corresponding nozzle.

When the inkjet head is a so-called serial head that moves in a direction perpendicular to the feed direction, the feed of the printing medium is performed when the landing position of the ink from a nozzle deviates in the nozzle arrangement direction. White streaks occur in the direction perpendicular to the direction. However, in the third aspect of the invention, by supplying the drive signal with an appropriate discharge timing to the ink discharge pressure applying means corresponding to the nozzle while moving the inkjet head in the nozzle arrangement direction by the head drive means. Deviations in the landing positions in the nozzle arrangement direction can be corrected, and white streaks can be prevented to improve print quality.

An ink jet printer according to a fourth invention is characterized in that, in any one of the first to third inventions, the drive signal generating means generates a plurality of types of drive signals having different ejection timings. is there. Accordingly, by supplying a drive signal of the discharge timing corresponding to the deviation amount of the landing position of the ink discharged from the corresponding nozzle to the plurality of ink discharge pressure applying means, the discharge timing from the nozzle is changed to the landing position. It can be easily and appropriately determined according to the amount of deviation.

An ink jet printer according to a fifth aspect of the present invention is the ink jet printer according to the fourth aspect , wherein the head control means has storage means for storing the types of the drive signals respectively supplied to the plurality of ink discharge pressure applying means. It is what. The storage means stores in advance the types of drive signals respectively supplied to the plurality of ink discharge pressure applying means, so that each time an ink discharge operation is performed from a certain nozzle, the head control means applies to that nozzle. There is no need to determine the type of drive signal supplied to the corresponding ink discharge pressure applying means, and the configuration of the head control means is simplified.

An ink jet printer according to a sixth invention is the ink jet printer according to any one of the first to fifth inventions, wherein the head driving unit is configured to reciprocate the ink jet head in the predetermined direction, and the head control unit includes: The ink ejection operation by the plurality of nozzles is performed once during the forward or backward movement of the inkjet head. In other words, since the forward or backward movement of the inkjet head and the ink discharge operation by the plurality of nozzles are synchronized, the discharge timing from the nozzles can be set according to the amount of deviation of the landing position in the nozzle arrangement direction. It becomes easy.

An ink jet printer according to a seventh aspect is the ink jet printer according to the sixth aspect , wherein the head control means has the same amount of deviation from the drive signal generating means to each of the plurality of ink discharge pressure applying means. In addition, by alternately supplying two types of drive signals corresponding to two deviation amounts whose directions of deviation are opposite to each other with respect to the predetermined direction, corresponding to forward movement and backward movement of the inkjet head, respectively. The ink ejection operation by the plurality of nozzles is performed once during the forward movement and the backward movement of the inkjet head. Accordingly, when the ink jet head is moved forward and backward, two types of drive signals corresponding to two displacement amounts whose directions of displacement are opposite to each other are alternately supplied to the ink discharge pressure applying means. In both forward and backward movements, the ink discharge operation can be performed once while correcting the deviation of the landing position, so that the generation of white streaks is suppressed and the printing quality is improved and the printing speed is increased. Is possible.

An ink jet printer according to an eighth aspect of the present invention is the ink jet printer according to any one of the first to seventh aspects, wherein the head control unit continuously discharges ink from the plurality of nozzles arranged in the predetermined direction. The head driving means is controlled to move the inkjet head in the predetermined direction. In this case, compared with the case where the inkjet head moves intermittently, the burden on the head driving means is reduced, which is advantageous in terms of durability.

Embodiments of the present invention will be described. The first embodiment is an example in which the present invention is applied to an inkjet printer having a line-type inkjet head.
As shown in FIG. 1, the ink jet printer 1 of the first embodiment is a line type ink jet that extends in the left-right direction of FIG. 1 and is movably arranged in the left-right direction of FIG. A head 3, a feed mechanism 4 (feed means) that moves the recording paper P (printed body) forward in FIG. 1, and a head drive mechanism 5 (head drive means) that reciprocates the inkjet head 3 in the longitudinal direction thereof. A control device 6 (see FIG. 6) that controls the entire inkjet printer 1 is provided.

First, the inkjet head 3 will be described.
As shown in FIGS. 2 to 4, the inkjet head 3 is configured to change the volume of the pressure unit 14 and the flow path unit 7 in which the individual ink flow path 21 including the pressure chamber 14 communicating with the nozzle 20 is changed. And an actuator unit 8 that applies pressure to the ink in the chamber 14. FIG. 2 is a partially enlarged plan view of the end portion of the inkjet head 3.

  As shown in FIG. 4, the flow path unit 7 includes a cavity plate 10, a base plate 11, a manifold plate 12, and a nozzle plate 13, and these four plates 10 to 13 are bonded in a stacked state. Among these, the cavity plate 10, the base plate 11 and the manifold plate 12 are stainless steel plates, and ink flow paths such as a manifold 17 and a pressure chamber 14 described later can be easily etched in these three plates 10-12. It can be formed. The nozzle plate 13 is formed of, for example, a polymer synthetic resin material such as polyimide, and is bonded to the lower surface of the manifold plate 12.

  As shown in FIGS. 2 to 4, the cavity plate 10 is formed with a plurality of pressure chambers 14 arranged along a plane. The plurality of pressure chambers 14 are open on the surface of the flow path unit 7 (the upper surface of the cavity plate 10 to which a diaphragm 30 described later is joined). The plurality of pressure chambers 14 are arranged in two rows in the scanning direction (left and right direction in FIGS. 1 and 2). Each pressure chamber 14 is formed in a substantially elliptical shape in plan view, and is arranged so that the major axis direction thereof is the vertical direction (feeding direction). The cavity plate 10 is formed with an ink supply port 18 connected to an ink tank (not shown).

  As shown in FIGS. 3 and 4, communication holes 15 and 16 are formed at positions overlapping the both ends in the long axis direction of the pressure chamber 14 in a plan view of the base plate 11, respectively. Further, the manifold plate 12 is formed with a manifold 17 that extends in the scanning direction (left-right direction in FIG. 2) and overlaps either the upper or lower end of the pressure chamber 14 in FIG. Ink is supplied to the manifold 17 from an ink tank through an ink supply port 18. A communication hole 19 is also formed at a position overlapping the end of the pressure chamber 14 opposite to the manifold 17 in plan view. Further, the nozzle plate 13 is formed with a plurality of nozzles 20 at positions overlapping the plurality of communication holes 19 in plan view. The nozzle 20 is formed, for example, by performing excimer laser processing on a polymer synthetic resin substrate such as polyimide.

  As shown in FIG. 4, the manifold 17 communicates with the pressure chamber 14 through the communication hole 15, and the pressure chamber 14 communicates with the nozzle 20 through the communication holes 16 and 19. In this way, the individual ink flow path 21 extending from the manifold 17 to the nozzle 20 through the pressure chamber 14 is formed in the flow path unit 7.

  As shown in FIGS. 2 to 4, the actuator unit 8 has a conductive diaphragm 30 disposed on the upper surface of the flow path unit 7 and the upper surface of the diaphragm 30 continuously across the plurality of pressure chambers 14. And a plurality of individual electrodes 32 respectively formed on the upper surface of the piezoelectric layer 31 so as to correspond to the plurality of pressure chambers 14.

  The diaphragm 30 is a substantially rectangular stainless steel plate in plan view. The diaphragm 30 is laminated and bonded to the upper surface of the cavity plate 10 in a state in which the openings of the plurality of pressure chambers 14 are closed. The diaphragm 30 also serves as a common electrode that opposes the plurality of individual electrodes 32 and applies an electric field to the piezoelectric layer 31 between the individual electrodes 32 and the diaphragm 30.

  On the surface of the diaphragm 30, a piezoelectric layer 31 mainly composed of lead zirconate titanate (PZT), which is a solid solution and is a ferroelectric substance, is formed of lead titanate and lead zirconate. The piezoelectric layer 31 is continuously formed across the plurality of pressure chambers 14. The piezoelectric layer 31 can be formed, for example, by sticking a piezoelectric sheet generated by firing a PZT green sheet on the vibration plate 30. Alternatively, the piezoelectric layer 31 may be formed by depositing PZT particles on the vibration plate 30 by an aerosol deposition method (AD method), a sputtering method, or the like.

  On the surface of the piezoelectric layer 31, a plurality of individual electrodes 32 having an elliptical planar shape that is slightly smaller than the pressure chamber 14 are formed by a method such as screen printing. Each of the plurality of individual electrodes 32 is formed at a position overlapping the central portion of the corresponding pressure chamber 14 in plan view. The individual electrode 32 is made of a conductive material such as gold. Furthermore, on the surface of the piezoelectric layer 31, a plurality of terminal portions 35 respectively extending from the end portions on the manifold 17 side of the plurality of individual electrodes 32 are formed. The plurality of terminal portions 35 are electrically connected to a later-described driver IC 37 via a flexible wiring member such as a flexible printed wiring board, and a plurality of individual electrodes are connected from the driver IC 37 via the terminal portion 35. A drive voltage is selectively supplied to 32.

  A discharge pressure is applied to the ink in the pressure chamber 14 by one individual electrode 32 facing one pressure chamber 14, and the piezoelectric layer 31 and the diaphragm 30 in a portion facing the individual electrode 32. One actuator 22 is configured to eject ink from the nozzle 20 communicating with the pressure chamber 14. This actuator 22 corresponds to the ink discharge pressure applying means of the present application.

Next, the operation of the actuator 22 will be described.
When a drive signal is supplied from a driver IC 37 to a certain actuator 22 and a drive voltage is applied to the individual electrode 32, the actuator 22 is held at the ground potential with the individual electrode 32 above the piezoelectric layer 31 to which the drive voltage is supplied. The potential of the diaphragm 30 as a common electrode under the piezoelectric layer 31 is different, and an electric field in the vertical direction is generated in the portion of the piezoelectric layer 31 sandwiched between the individual electrode 32 and the diaphragm 30. Then, the portion of the piezoelectric layer 31 directly below the individual electrode 32 to which the drive voltage is applied contracts in the horizontal direction orthogonal to the vertical direction that is the polarization direction. At this time, as the piezoelectric layer 31 contracts, the vibration plate 30 is deformed so as to protrude toward the pressure chamber 14, so that the volume in the pressure chamber 14 decreases.

  In the first embodiment, in a state where ink is not ejected from the nozzle 20, the drive voltage is always applied to the individual electrode 32 and the volume of the pressure chamber 14 is reduced. When ink is ejected from the nozzle 20, the volume of the pressure chamber 14 is once increased by setting the individual electrode 32 to the ground potential, and after the ink is drawn into the pressure chamber 14 from the manifold 17, the individual electrode 32 is again separated. A drive voltage is applied to the electrode 32 to reduce the volume of the pressure chamber 14, and pressure is applied to the ink in the pressure chamber 14, so that ink is ejected by so-called striking.

Next, the feed mechanism 4 will be described.
As shown in FIG. 1, the feed mechanism 4 includes two transport rollers 40 and 41 disposed before and after the inkjet head 3, and a transport motor 42 (see FIG. 6) that rotationally drives the transport rollers 40 and 41. It has. The feed mechanism 4 is configured to move the recording paper P in the feed direction (forward in FIG. 1) by rotating the transport rollers 40 and 41 by the transport motor 42.

Next, the head drive mechanism 5 will be described. As will be described later, the head driving mechanism 5 changes the ink ejection timing from the plurality of nozzles 20 so that the ink landing position in the arrangement direction of the nozzles 20 (the horizontal direction in FIG. 1) can be adjusted. This is for reciprocating the inkjet head 3 in this arrangement direction.
As shown in FIG. 1, the head driving mechanism 5 includes a piezoelectric actuator 44 provided between one end of the printer main body 2 and the inkjet head 3 (left end in FIG. 1), the printer main body 2 and the inkjet head 3. And an elastic member 45 provided between the other end (the right end in FIG. 1).

  As shown in FIG. 5, the piezoelectric actuator 44 has a structure in which a plurality of piezoelectric sheets 46 mainly composed of PZT are laminated. Between the plurality of piezoelectric sheets 46, a first electrode 47 to which a drive voltage is applied by a drive circuit 56 (see FIG. 6) and a second electrode 48 held at the ground potential are interposed. When a drive voltage is applied to the first electrode 47, an electric field acts on the piezoelectric sheet 46 sandwiched between the first electrode 47 and the second electrode 48 in the thickness direction (left and right direction in FIG. 5). Since the piezoelectric sheet 46 extends in the thickness direction, the inkjet head 3 is pressed rightward in FIG.

  The elastic member 45 is for pushing back the inkjet head 3 that has been pressed and moved rightward by the piezoelectric actuator 44 to the left. The elastic member 45 may be a spring member such as a coil spring or a disc spring, or may be an elastic member made of elastic rubber or the like. The inkjet head 3 is reciprocated in the left-right direction by the action of the piezoelectric actuator 44 and the elastic member 45 located at both ends of the inkjet head 3. In the first embodiment, the amplitude A of the reciprocating operation of the inkjet head 3 is about 30 to 50 μm.

Next, the electrical configuration of the inkjet printer 1 will be described focusing on the control device 6.
As shown in FIG. 6, the control device 6 includes a CPU 50 (Central Processing Unit), a ROM 51 (Read Only Memory), a RAM 52 (Random Access Memory), and various types including image data with an external personal computer (PC) 60. A communication interface (I / F) 53 for exchanging data, an image memory 54 for storing print data input from the PC 60, and the like are included.

  The CPU 50 outputs various signals to the driver IC 37 of the inkjet head 3, the drive circuit 55 that drives the conveyance motor 42, the drive circuit 56 that drives the piezoelectric actuator 44, and the like. The ROM 51 controls various operations of the ink jet printer 1 such as an ink ejection operation by the ink jet head 3, a reciprocating operation of the ink jet head 3 by the piezoelectric actuator 44, or a recording paper P feeding operation by the transport motor 42. Various programs and data are stored. Further, the RAM 52 temporarily stores various data necessary for executing the program stored in the ROM 51.

  By the way, when printing on the recording paper P, the control device 6 outputs pulse-shaped drive waveform data to the driver IC 37, and the driver IC 37 is based on the drive waveform input from the control device 6. A drive signal is generated and a predetermined drive signal is supplied to the individual electrode 32 of the actuator 22. Then, as described above, pressure is applied to the ink by the actuator 22 so that the ink is ejected from the nozzle 20.

  Here, in order to reduce the size of the inkjet head 3 and improve the printing quality, it is preferable that the plurality of nozzles 20 arranged in the direction orthogonal to the feeding direction of the recording paper P are formed with high accuracy. In order to realize this, it is necessary to strictly manage the processing accuracy of the nozzle 20, and defective products that do not satisfy the processing accuracy in the manufacturing process of the inkjet head 3 increase, resulting in a decrease in yield. However, if the processing accuracy of the nozzles 20 is set to be loose, due to processing errors, the landing positions of the ink ejected from some of the nozzles 20 are changed from the normal landing positions (positions immediately below the nozzles 20) to the arrangement direction of the nozzles 20. In some cases, the recording paper P may be greatly deviated with respect to the feeding direction.

  For example, as shown in FIGS. 8A and 8B, a plurality (17) of nozzles 20 (in FIG. 8A, FIG. 8B and FIG. 9 the arrangement direction of the nth nozzle 20 from the left). (N) is also arranged in the left-right direction (the same applies to FIGS. 14 to 20 described later). In particular, with respect to some of the nozzles 20, the flying direction of the ink ejected from the nozzles 20 is tilted to the right or left, and the ink landing positions are shifted in the arrangement direction (left-right direction in FIG. 8). In the case (specifically, the landing position of the ink from the 13th nozzle 20 is greatly shifted to the right, the landing position of the ink from the third nozzle 20 is slightly shifted to the right, and further from the 10th nozzle 20) When the ink landing position is slightly shifted to the left), there is a gap between the dot D formed by such a nozzle 20 and the dot D formed by the nozzle 20 adjacent to the nozzle 20 in the arrangement direction. As a result, white streaks extending in the feeding direction of the recording paper P are formed as shown in FIG.

  Therefore, in the inkjet printer 1 of the first embodiment, the ejection timing is different from the driver IC 37 while moving the inkjet head 3 in the direction parallel to the arrangement direction of the nozzles 20 (rightward in FIG. 8) by the head driving mechanism 5. By supplying any one of the five types of drive signals to the actuator 22, the ink ejection timing from the nozzle 20 whose landing position is shifted is different from that of the other nozzles 20, and the deviation of the landing position is corrected. It is configured to be able to. The control device 6 that performs such control corresponds to the head control means of the present invention.

  As shown in FIG. 7, the control device 6 is supplied to each actuator 22 from a waveform generator 57 that generates waveforms of five types of drive signals (drive waveforms 1 to 5) having different ejection timings, and a driver IC 37. And a selection data generation unit 58 that generates 3-bit selection data (d1, d2, d3: see FIG. 13) for selecting the type of drive signal. The waveform generation unit 57 and the selection data generation unit 58 are configured by a CPU 50, a ROM 51, a RAM 52, an image memory 54, and the like.

  FIG. 10 shows five types of drive waveforms 1 to 5 generated by the waveform generation unit 57. Here, as described above, the inkjet head 3 according to the first embodiment is configured to eject ink from the nozzle 20 by striking, and once the drive voltage is applied to the individual electrode 32, the individual is temporarily separated. After the ink is drawn from the manifold 17 into the pressure chamber 14 with the electrode 32 as the ground potential, the drive voltage is applied to the individual electrode 32 again. Therefore, as shown in FIG. 10, in the drive waveforms 1 to 5, the timing when L → H (the position of the dashed line in FIG. 10) is the ejection timing. Further, in the drive waveforms 1 to 5, the discharge timings are different from each other. First, the ejection timing of the drive waveform 3 is set to be the timing at which ink is ejected from the nozzle 20 when the nozzle 20 arrives almost immediately above the normal landing position. The drive waveform 2 has a discharge timing earlier than the drive waveform 3 by a time T0, and the drive waveform 1 has a discharge timing earlier than the drive waveform 2 by a time T0. On the other hand, the ejection timing of the driving waveform 4 is later than the driving waveform 3 by the time T0, and the ejection timing of the driving waveform 5 is further delayed by the time T0 than the driving waveform 4.

  The time difference T0 of the ejection timing is substantially equal to the time taken to move a distance of 1/4 of the amplitude A when the inkjet head 3 moves from left to right. The time difference 4T0 between the discharge timing of the earliest drive waveform 1 and the discharge timing of the latest drive waveform 5 is the vicinity of the left end position of the inkjet head 3 (strictly speaking, immediately after the start of movement from left to right). It is equal to the time taken to move from the position (1) to the vicinity of the right end position. In other words, the nozzle 20 associated with the drive waveform 1 ejects ink when the inkjet head 3 is near the left end position, and the nozzle 20 associated with the drive waveform 3 Ink is ejected when in an intermediate position, and the nozzle 20 associated with the drive waveform 5 ejects ink when the inkjet head 3 is near the right end position. Then, while the inkjet head 3 moves from the left to the right, one ink ejection operation by the plurality of nozzles 20 arranged in the left-right direction is performed at each ejection timing.

  The selection data generation unit 58 uses five driver waveforms 1 to 5 for each nozzle 20 (actuator 22 corresponding to each nozzle 20) by a driver IC 37, which will be described later, or a drive waveform (constant voltage) when ink is not ejected. Selection data d1 to d3 for selecting any one of the waveform (1). Here, when ink is ejected from each of the plurality of nozzles 20, the type of drive waveform selected for each of the plurality of nozzles 20 is ink ejected from the nozzles 20 when the inkjet head 3 is stationary. The predetermined landing position is determined in advance corresponding to the deviation amount with respect to the normal landing position (position immediately below the nozzle 20) in the arrangement direction of the nozzles 20. That is, in the manufacturing process, when the assembly of the inkjet head 3 is completed, ink is ejected from the nozzle 20 with the inkjet head 3 being stationary, and the amount of deviation of the landing position from the normal landing position is measured. . Then, one drive waveform is selected for one nozzle 20 based on the measured amount of landing position deviation and the relationship shown in FIG. The correspondence between the plurality of nozzles 20 and the drive waveforms obtained by performing this process for all the nozzles 20 is stored in the ROM 51. This ROM 51 corresponds to the storage means of the present invention. In FIG. 11, “+” in the shift amount column indicates that the landing position is shifted to the right in FIG. 8, and “−” indicates that the landing position is shifted to the left in FIG. . If the amount of deviation (absolute value) exceeds 30 μm, it is judged as a defective product that cannot correct the deviation of the landing position even if the ejection timing is shifted, and is excluded from the production line. Is done. Since the correspondence between the plurality of nozzles 20 and the drive waveforms 1 to 5 is stored in the ROM 51 in this way, each time ink is ejected from the nozzles 20, one drive waveform is displayed according to the amount of deviation of the landing position. There is no need to decide.

  For example, as shown in FIG. 8, the nozzles 20 stored in the ROM 51 when the landing positions of the three nozzles 20 (third, tenth, and thirteenth nozzles 20) are shifted to the left or right. FIG. 12 shows the correspondence between the driving waveform and the driving waveform. That is, since the landing position of the ink from the third nozzle 20 is slightly shifted to the right, it is necessary to eject the ink before the inkjet head 3 moving from the left reaches the center position. The drive waveform 2 having a slightly early discharge timing is selected. Further, since the landing position of the ink from the tenth nozzle 20 is slightly shifted to the left, the drive waveform 4 having a slightly later ejection timing is selected. Further, since the ink landing position from the thirteenth nozzle 20 is considerably shifted to the right, the driving waveform 1 having the earliest ejection timing is selected. The drive waveform 3 is selected for the other nozzles 20 with almost no landing position deviation.

  The selection data generation unit 58 is based on the correspondence between the print data stored in the image memory 54 and the nozzles 20 stored in the ROM 51 and the drive waveforms shown in FIG. 12 for each ink ejection operation. Thus, selection data d1 to d3 composed of 3-bit bit data respectively corresponding to the plurality of nozzles 20 are generated. FIG. 13 shows the correspondence between the selection data d1 to d3 and the drive waveforms 1 to 5. The 3-bit selection data d1 to d3 generated by the selection data generation unit 58 is serially output to the driver IC 37 described below.

Next, a plurality of types of drive signals having different ejection timings based on the five types of drive waveforms 1 to 5 generated by the waveform generation unit 57 and the selection data d1 to d3 generated by the selection data generation unit 58. A driver IC 37 (driving signal generating means) that generates the above will be described.
As shown in FIG. 7, the driver IC 37 includes a shift register 61 as a serial-parallel converter that converts 3-bit selection data d1 to d3 serially input from the selection data generation unit 58, a latch circuit 62, A waveform selection circuit 63 for selecting one drive waveform from the plurality of drive waveforms 1 to 5 based on selection data corresponding to each of the plurality of nozzles 20 is provided.

The 3-bit selection data d1 to d3 generated by the selection data generation unit 58 are serially input to the shift register 61 in order in synchronization with the transfer clock CLK. Then, the shift register 61 converts the serially input selection data d <b> 1 to d <b> 3 to parallel conversion and outputs the parallel data to the latch circuit 62.
The latch circuit 62 is composed of a D-flip-flop, and the parallel-selected selection data d1 to d3 are converted into a waveform selection circuit 63 composed of a multiplexer in accordance with the rising of the strobe control signal STB transferred from the control device 6. Output to.

The waveform signal selection circuit 63 is inputted with 3-bit selection data d1 to d3 and five types of drive waveforms 1 to 5, and further, although not shown, a constant voltage waveform corresponding to a mode in which ink is not ejected is also inputted. The Then, one corresponding drive waveform is selected from the five types of drive waveforms 1 to 5 and the constant voltage waveform corresponding to the mode in which ink is not ejected based on the 3-bit selection data d1 to d3 (or , Select a low voltage waveform that does not eject ink), and output the waveform to the drive buffer 64.
The drive buffer 64 generates a drive signal OUTx (x = 1, 2,..., N, n is the number of nozzles) having a predetermined voltage from the waveform output from the waveform selection circuit 63, and uses this drive signal OUTx as the actuator 22. To supply.

  Next, the ink ejection operation of the inkjet head 3 when the landing positions of the ink ejected from some of the nozzles 20 are deviated will be described with reference to the example of FIG. 8 again. As shown in FIG. 8, in this example, the flying direction of the ink ejected from some of the nozzles 20 (third, tenth and thirteenth nozzles 20) is inclined to the right or left, The landing position is deviated from the normal landing position in the left-right direction, which is the arrangement direction of the nozzles 20. Hereinafter, a case where ink is ejected from all of a plurality (17) of nozzles 20 arranged in one row will be described.

  Here, since the landing position of the ink ejected from the third nozzle 20 is slightly shifted to the right, as shown in FIG. The drive waveform 2 whose ejection timing is earlier by the time T0 is associated with the drive waveform 3 selected when ink is ejected almost immediately above the position. Further, since the landing position of the ink ejected from the tenth nozzle 20 is slightly shifted to the left, the tenth nozzle 20 has an ejection timing of time T0 from the driving waveform 3 as shown in FIG. A slow driving waveform 4 is associated. Further, since the landing position of the ink ejected from the 13th nozzle 20 is greatly shifted to the right, the ejection timing of the 13th nozzle 20 is longer than the drive waveform 3 by a time 2T0 as shown in FIG. The fast driving waveform 1 is associated. The drive waveform 3 is associated with the other nozzles 20 whose landing positions are not shifted.

  When the ink is ejected from the inkjet head 3, the selection data generation unit 58 of the control device 6 refers to the correspondence relationship between the nozzle 20 of FIG. 20-bit selection data d1 to d3 are generated. Then, the selection data d1 to d3 are transferred to the driver IC 37. The driver IC 37 generates a driving signal having a driving waveform corresponding to each nozzle 20 based on the selection data d1 to d3, and corresponds to the nozzle 20. The drive signal is supplied to the actuator 22. At the same time, the control device 6 drives the piezoelectric actuator 44 to move the inkjet head 3 to the right from the left end position.

  When the drive signal is supplied to the actuator 22, as shown in FIGS. 14 to 18, ink is discharged from the nozzle 20 at the discharge timing of the supplied drive signal. In FIG. 14B, FIG. 15B, FIG. 17B, and FIG. 18B, the position of the inkjet head 3 indicated by the two-dot chain line moves from the left to the right. In FIG. 16B, the ink is ejected from the nozzle 20 that is at an intermediate position and has no landing position deviation associated with the drive waveform 3. First, as shown in FIGS. 14A and 14B, immediately after the inkjet head 3 starts to move to the right from the left end position, the drive signal of the drive waveform 1 is supplied to the corresponding actuator 22. Ink is ejected from the 13th nozzle 20. At this time, ink is ejected from the thirteenth nozzle 20 with a large inclination to the right. The thirteenth nozzle 20 is positioned immediately above the normal landing position (the inkjet head 3 is positioned at the position of the two-dot chain line). Since it is at a position far to the left than a certain state), the rightward shift of the landing position is canceled out, and the dot D is formed at a position very close to the normal landing position.

  As shown in FIGS. 15A and 15B, when the inkjet head 3 further moves to the right by a distance of about ¼ of the amplitude A, the drive signal of the drive waveform 2 is supplied to the corresponding actuator 22. Then, ink is ejected from the third nozzle 20. Ink is ejected from the third nozzle 20 with a slight incline to the right, but the third nozzle 20 is located slightly to the left of the position just above the normal landing position. The shift to the right is offset.

  Then, as shown in FIGS. 16A and 16B, when the inkjet head 3 reaches an intermediate position in the rightward movement, the drive signal of the drive waveform 3 is supplied to the corresponding actuator 22. Ink is ejected from a plurality (14) of nozzles 20 other than the third, tenth and thirteenth nozzles 20. Since the displacement of the landing positions of the ink ejected from these nozzles 20 is originally small, the ink is landed in the vicinity of the regular landing positions almost directly below the nozzles 20.

  Further, as shown in FIGS. 17A and 17B, when the inkjet head 3 is further moved to the right by a distance of about 1/4 of the amplitude A, the drive signal of the drive waveform 4 is applied to the corresponding actuator 22. Ink is ejected from the supplied tenth nozzle 20. Ink is ejected from the tenth nozzle 20 with a slight tilt to the left, but the tenth nozzle 20 is located slightly to the right of the position just above the normal landing position, so The shift to the left is offset.

  Further, as shown in FIGS. 18A and 18B, the inkjet head 3 further moves rightward and reaches the vicinity of the right end position. Here, in this example, there is no nozzle 20 associated with the drive waveform 5 (nozzle 20 whose landing position is greatly shifted to the left), but when such a nozzle 20 is present, the inkjet head 3 is connected to the right end. When the vicinity of the position is reached, ink is ejected from the nozzle 20. Then, one ink ejection operation from a plurality (17) of nozzles 20 arranged in a row is completed.

  When one ink ejection operation from all the nozzles 20 is completed, as shown in FIGS. 19A and 19B, the ink jet head 3 is returned to the left by the elastic force of the elastic member 45, and the feed mechanism 4, the recording paper P is fed forward at a predetermined pitch, and the next ink ejection operation is performed. In this way, the control device 6 controls the feeding mechanism 4 so as to feed the recording paper P for each ink ejection operation from the plurality of nozzles 20, so that the feeding direction of the recording paper P for the plurality of arranged nozzles 20. The deviation of the landing position can be reduced.

  By performing the ink ejection operation as described above, the deviation of the landing position in the arrangement direction of the ink ejected from the plurality of nozzles 20 arranged in the left-right direction is corrected, as shown in FIG. In addition, since the dots D are formed on the recording paper P without gaps in the arrangement direction of the nozzles 20, white streaks do not occur on the recording paper P, and the printing quality is improved.

  In the inkjet printer 1 according to the first embodiment, the control device 6 continuously moves the inkjet head 3 in the left-right direction while ink is ejected from the plurality of nozzles 20 arranged in the left-right direction. Thus, the head driving mechanism 5 is controlled. In this case, the burden on the piezoelectric actuator 44 is reduced as compared with the case where the inkjet head 3 moves intermittently each time ink is ejected from the nozzle 20 at the ejection timing of the drive waveforms 1 to 5. This is advantageous in terms of durability. However, since the ink is ejected from the nozzle 20 while moving the inkjet head 3 to the left, the velocity component to the right of the inkjet head 3 is added in vector to the flying speed of the ink ejected downward. The Therefore, the ink is landed with a slight shift to the right as compared with the case where the ink is ejected from the stationary inkjet head 3. Therefore, the ink jet head 3 performs recording so that the nozzle 20 is located slightly to the left of the normal landing position in a state where the ink jet head 3 has reached the intermediate position shown in FIGS. It is preferable that the sheet P is disposed slightly to the left of the sheet P as a whole.

According to the inkjet printer 1 described above, the following effects can be obtained.
Even when the landing position of the ink ejected from the nozzle 20 deviates from the normal landing position in the nozzle 20 arrangement direction due to the processing error of the nozzle 20, the inkjet head 3 is moved in the nozzle 20 arrangement direction. In addition, by discharging ink from the nozzles 20 at an appropriate discharge timing, it is possible to easily correct the deviation of the landing position without performing a complicated operation. Therefore, it is possible to prevent white streaks extending in the feeding direction of the recording paper P and to improve the printing quality. Further, since the deviation of the landing position can be corrected after the ink jet head 3 is assembled, the processing accuracy of the nozzle 20 required in the manufacturing stage can be relaxed, and the manufacturing cost can be reduced.

  The inkjet printer 1 is configured such that one ink ejection operation is performed from the plurality of nozzles 20 of the inkjet head 3 while the inkjet head 3 moves from the left to the right. The movement from the left to the right and the ink ejection operation from the plurality of nozzles 20 are performed in synchronization. Therefore, the discharge timing from the nozzle 20 can be set according to the amount of deviation of the landing position in the arrangement direction of the nozzles 20 only by making each nozzle 20 correspond to any one of a plurality of drive signals having different discharge timings. The ejection timing can be set more easily than in the case where the movement of the inkjet head 3 and the ink ejection operation are not performed in synchronization.

Next, modified embodiments in which various modifications are made to the first embodiment will be described. However, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted as appropriate.
1] The inkjet printer 1 of the first embodiment is configured to eject ink from a plurality of nozzles 20 while continuously moving the inkjet head 3 to the left (see FIGS. 14 to 18). ) Each time ink is ejected at the ejection timing of the drive waveforms 1 to 5, the inkjet head 3 may be moved intermittently by a distance of about 1/4 of the amplitude A. In this case, since the ink jet head 3 can be stopped and ink can be ejected from the nozzle 20, unlike the embodiment, the velocity component to the right of the ink jet head 3 is a vector in the flying speed of the ejected ink. Are not added.

  2] The ink jet printer 1 according to the first embodiment intermittently feeds the recording paper P forward by the feed mechanism 4 every time one ink ejection operation from the plurality of nozzles 20 arranged in the left-right direction is completed. Although it is configured to feed (see FIG. 19), it may be configured to continuously feed the recording paper P forward by the feeding mechanism 4 while performing the ink ejection operation from the plurality of nozzles 20.

  3] The configuration of the head drive mechanism 5 is not limited to the configuration of the first embodiment. For example, the elastic member 45 of the head driving mechanism 5 may be replaced with the piezoelectric actuator 44, and the inkjet head 3 may be driven to reciprocate in the left-right direction by the two piezoelectric actuators 44 provided at both ends of the inkjet head 3. . Furthermore, an actuator other than the piezoelectric actuator 44 can be employed.

  4] The ink jet printer 1 of the first embodiment performs the ink discharge operation from the nozzle 20 only in one of the reciprocating operations of the ink jet head 3 in the arrangement direction of the nozzles 20 (either forward movement or backward movement). Although it is configured to perform (see FIGS. 14 to 19), the ink ejection operation may be performed once each between the forward movement and the backward movement.

  However, it is necessary to change the ejection timing of the ink from each nozzle 20 between the forward movement and the backward movement of the inkjet head 3. For example, in FIG. 8 of the first embodiment, the ink landing position from the third nozzle 20 is shifted to the right from the position immediately below the nozzle 20, so that the inkjet head 3 moves from the left to the right. Sometimes it is necessary to eject ink at an early ejection timing, but when the inkjet head 3 moves from right to left, it is necessary to eject ink at a later ejection timing.

  Therefore, in the ink jet printer of this modified embodiment, two types of drive signals are associated with the forward and backward movements of the ink jet head 3 for the nozzles 20 whose landing positions are shifted, and these two types of drive signals are controlled. It is stored in the ROM 51 in the device 6. Here, the two types of drive signals are drive signals having drive waveforms respectively corresponding to two shift amounts whose shift amounts are equal and whose shift directions are opposite to each other with respect to the arrangement direction of the nozzles 20. . When the drive signals having the above-described five types of drive waveforms 1 to 5 shown in FIG. 10 are supplied to the actuator 22, the drive signal of the drive waveform 1, the drive signal of the drive waveform 5, and the drive signal of the drive waveform 2. And the drive signal of the drive waveform 4 correspond to the above-described two types of drive signals, respectively. For example, in the case of FIG. 8 of the first embodiment, the types of drive waveforms associated with the nozzles 20 are as shown in FIG. In other words, the third nozzle 20 whose landing position is slightly shifted to the right is associated with the drive waveform 2 having a slightly early discharge timing during forward movement (movement from left to right), while When moving (moving from the right side to the left side), the drive waveform 4 having a slightly late discharge timing is associated. The tenth nozzle 20 whose landing position is slightly shifted to the left is associated with the driving waveform 4 during forward movement and the driving waveform 2 during backward movement. Further, the thirteenth nozzle 20 whose landing position greatly deviates to the right is associated with a driving waveform 1 during forward movement and a driving waveform 5 during backward movement.

  In this way, by associating two types of drive signals with each of the forward movement and the backward movement, it is possible to perform the ink ejection operation once each during the forward movement and the backward movement. Since both the forward movement and the backward movement of the inkjet head 3 can perform the ink discharge operation once while correcting the deviation of the landing position, the forward movement or the like as in the first embodiment. The printing speed can be increased compared to the case where the ink ejection operation is performed only at any time during the backward movement.

  Next, a second embodiment of the present invention will be described. The second embodiment is an example in which the present invention is applied to an ink jet printer having a serial ink jet head. However, components having the same configuration as in the first embodiment are denoted by the same reference numerals, and description thereof is omitted as appropriate.

  As shown in FIGS. 22 and 23, the inkjet printer 71 of the second embodiment includes a carriage 77 that can move in the left-right direction with respect to the printer main body 72, and a plurality of nozzles 20 that are held by the carriage 77. An inkjet head 73, a feed mechanism 4 that feeds the recording paper P in the front-rear direction, a head drive mechanism 75 that reciprocates the inkjet head 73 in the front-rear direction relative to the carriage 77, and overall control of the inkjet printer. And the like.

The carriage 77 is driven in the left-right direction along two front and rear guide shafts 80 by a carriage drive motor 79 (carriage drive means: see FIG. 23).
The inkjet head 73 includes a plurality of nozzles 20 arranged in parallel with the front-rear direction that is the feed direction. A piezoelectric actuator 44 and an elastic member 45 of the head drive mechanism 75 are interposed between the inkjet head 73 and the carriage 77, respectively. The piezoelectric actuator 44 and the elastic member 45 are the same as those in the first embodiment, and a description thereof will be omitted. The feeding mechanism 4 is also the same as that in the first embodiment including the transport rollers 40 and 41.

  As shown in FIG. 23, the control device 6 controls the carriage drive motor 79 via the drive circuit 78 while feeding the recording paper P forward by the feed mechanism 4 to move the inkjet head 73 in the left-right direction (scanning direction). To the recording paper P, and recording is performed on the recording paper P. At that time, the control device 6 supplies a drive signal from the driver IC 37 to the actuator unit 8 (actuator 22) while reciprocating the inkjet head 73 in the front-rear direction by the head drive mechanism 5, and the recording paper P from the plurality of nozzles 20 is supplied. Ink is discharged.

  Here, since the inkjet head 73 is a serial head that reciprocates in a direction orthogonal to the feed direction (front of FIG. 22), the ink landing position from a certain nozzle 20 is the arrangement direction of the nozzle 20 (FIG. 22). ), White streaks parallel to the scanning direction of the inkjet head 73 (left and right direction in FIG. 22) are generated. Therefore, in the ink jet printer 71, as in the first embodiment, when the ink is ejected from the nozzles 20 in a state where the ink jet printer 71 is stationary, the amount of deviation of the ink landing position in the arrangement direction of the nozzles 20 is reduced. Accordingly, five types of drive waveforms 1 to 5 (see FIG. 10) having different ejection timings are associated with the plurality of nozzles 20. Then, a drive signal having a drive waveform associated with the nozzle 20 is supplied from the driver IC 37 to each of the plurality of actuators 22 while reciprocating the inkjet head 73 in the front-rear direction by the head drive mechanism 75. It is possible to correct the deviation of the landing position with respect to the arrangement direction of the nozzles 20 (the front-rear direction which is the feed direction). Therefore, it is possible to prevent the occurrence of white stripes parallel to the scanning direction and improve the printing quality.

  The first embodiment and the second embodiment described above are examples of a configuration in which the driver IC 37 that is a drive signal generation unit is included in the inkjet heads 3 and 73, but the configuration in which the driver IC 37 is not included in the inkjet head. It may be. That is, the driver IC 37 may be disposed at a position away from the inkjet heads 3 and 73 as long as the driver IC 37 is connected to the actuator 22 to which the drive signal is supplied via the signal line.

1 is a schematic perspective view of an ink jet printer according to a first embodiment of the present invention. 2 is a partially enlarged plan view of an end portion of an inkjet head. FIG. FIG. 3 is a partially enlarged plan view of FIG. 2. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. It is sectional drawing of a piezoelectric actuator. It is a block diagram which shows the main electrical structures of an inkjet printer. It is a block diagram of a control device and a driver IC. It is a figure which shows the ink discharge operation | movement in the state which the inkjet head stopped, (a) is the figure seen from upper direction, (b) is the figure seen from the front. FIG. 9 is a diagram illustrating dots formed on a recording sheet as a result of the ink ejection operation of FIG. 8. It is a figure which shows five types of drive waveforms. It is a figure which shows the correspondence of the deviation | shift amount of a landing position, and a drive waveform. It is a figure which shows the correspondence of a nozzle and a drive waveform. It is a figure which shows the correspondence of selection data and a drive waveform. It is a figure which shows the ink discharge operation | movement immediately after the inkjet head moves to the right from the left, (a) is the figure seen from upper direction, (b) is the figure seen from the front. It is a figure which shows the ink discharge operation | movement when moving further to the right from FIG. 14, (a) is the figure seen from upper direction, (b) is the figure seen from the front. It is a figure which shows the ink discharge operation | movement when an inkjet head exists in an intermediate position, (a) is the figure seen from upper direction, (b) is the figure seen from the front. It is a figure which shows the ink discharge operation | movement when moving further to the right from FIG. 16, (a) is the figure seen from upper direction, (b) is the figure seen from the front. It is a figure which shows the ink discharge operation just before completion | finish of the movement of the inkjet head from the left to the right, (a) is the figure seen from upper direction, (b) is the figure seen from the front. 4A and 4B are diagrams illustrating a recording sheet feeding operation, in which FIG. 4A is a diagram viewed from above, and FIG. FIG. 19 is a diagram illustrating dots formed on a recording sheet as a result of the ink ejection operation of FIGS. 14 to 18. It is a figure which shows the correspondence of the nozzle and drive waveform of the modification of 1st Embodiment. It is a schematic perspective view of the inkjet printer of 2nd Embodiment. It is a block diagram which shows the main electrical structures of an inkjet printer.

DESCRIPTION OF SYMBOLS 1 Inkjet printer 3 Inkjet head 4 Feeding mechanism 5 Head drive mechanism 6 Control device 20 Nozzle 22 Actuator 71 Inkjet printer 73 Inkjet head 75 Head drive mechanism 76 Control device 77 Carriage 79 Carriage drive motor 37 Driver IC

Claims (8)

A plurality of nozzles arranged in a predetermined direction, and a plurality of ink discharge pressure applying units that are provided corresponding to the plurality of nozzles and that apply discharge pressure for discharging ink from the corresponding nozzles to the ink. An inkjet head;
Drive signal generating means for generating a drive signal supplied to the plurality of ink discharge pressure applying means;
A feeding means for moving the printing medium relative to the inkjet head;
Head drive means for moving the inkjet head in the predetermined direction;
Head control that applies ink discharge pressure to the ink by the plurality of ink discharge pressure applying means and discharges ink from the plurality of nozzles at predetermined discharge timings while moving the ink jet head in the predetermined direction by the head driving means. Means and
The inkjet head is a line-type head in which the predetermined direction which is an arrangement direction of the plurality of nozzles is orthogonal to a feeding direction of the printing medium by the feeding unit,
The head control means adjusts the amount of deviation of the ink landing position in the predetermined direction when ink is ejected from the corresponding nozzle to each of the plurality of ink ejection pressure application means from the drive signal generation means. An inkjet printer characterized by supplying the corresponding drive signal. The head control unit controls the feeding unit to intermittently feed the printing medium every time one ink ejection operation by the plurality of nozzles arranged in the predetermined direction is completed. The inkjet printer according to claim 1 . A plurality of nozzles arranged in a predetermined direction, and a plurality of ink discharge pressure applying units that are provided corresponding to the plurality of nozzles and that apply discharge pressure for discharging ink from the corresponding nozzles to the ink. An inkjet head;
Drive signal generating means for generating a drive signal supplied to the plurality of ink discharge pressure applying means;
A feeding means for moving the printing medium relative to the inkjet head;
Head drive means for moving the inkjet head in the predetermined direction;
Head control that applies ink discharge pressure to the ink by the plurality of ink discharge pressure applying means and discharges ink from the plurality of nozzles at predetermined discharge timings while moving the ink jet head in the predetermined direction by the head driving means. Means,
A carriage that holds the inkjet head and the head driving means; and a carriage driving means that reciprocates the carriage in a direction orthogonal to the feeding direction of the printing medium by the feeding means,
The inkjet head is disposed so that the predetermined direction, which is an arrangement direction of the plurality of nozzles, is parallel to the feeding direction,
The head control means adjusts the amount of deviation of the ink landing position in the predetermined direction when ink is ejected from the corresponding nozzle to each of the plurality of ink ejection pressure application means from the drive signal generation means. An inkjet printer characterized by supplying the corresponding drive signal. The inkjet printer according to claim 1, wherein the drive signal generation unit generates a plurality of types of drive signals having different ejection timings. 5. The ink jet printer according to claim 4 , wherein the head control unit includes a storage unit that stores types of the drive signals respectively supplied to the plurality of ink discharge pressure applying units. The head driving means is configured to reciprocate the inkjet head in the predetermined direction,
The ink jet printer according to claim 1, wherein the head control unit causes the ink ejection operation by the plurality of nozzles to be performed once during the forward or backward movement of the ink jet head. . The head control means has the same amount of deviation from the drive signal generating means to each of the plurality of ink ejection pressure applying means, and the directions of deviation are opposite to each other with respect to the predetermined direction. By alternately supplying two types of drive signals corresponding to the two displacement amounts in correspondence with the forward movement and the backward movement of the ink jet head, the ink jet head moves between the forward movement and the backward movement. The ink jet printer according to claim 6 , wherein the ink discharge operation by the plurality of nozzles is performed once. The head control unit controls the head driving unit to continuously move the ink jet head in the predetermined direction while ink is ejected from the plurality of nozzles arranged in the predetermined direction. An ink jet printer according to any one of claims 1 to 7 .

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