JP2009012339A - Fluid ejector and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To extend the life of each nozzle and to suppress cross talk of nozzles. <P>SOLUTION: Every other nozzles among first cyan nozzles NC1 linearly arranged along a longitudinal direction of a first cyan nozzle array C1, and every other second cyan nozzles NC1 not pairing with the earlier selected first cyan nozzles NC1 among second cyan nozzles NC2 similarly linearly arranged along the longitudinal direction are made a group A. First and second cyan nozzles NC1 and NC2 not belonging to the group A are made another group. Both groups are changed over by every predetermined timing to be set as a using object group. A fluid is ejected from the nozzles which belong to the set using object group. The action of relatively moving a target and a head after a dot array is formed to the target is repeated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fluid ejection device and a control method thereof.

Conventionally, fluid ejection devices that eject fluid from nozzles are known. For example, in the fluid ejection device disclosed in Patent Document 1, spare nozzle arrays corresponding to cyan and magenta are formed in order to recover defective nozzles. In this fluid ejecting apparatus, from the viewpoint that it is not desirable that the spare nozzle row is not used for a long period of time, the normal nozzle row that is not the spare nozzle row and the spare nozzle row are usually printed for each printing sheet or a predetermined job. It is decided to use it by switching every number. As a result, the life of each nozzle is extended.
JP2003-118149A (paragraphs 0037 and 0038)

  However, in such a fluid discharge device, although the main nozzle row and the spare nozzle row are switched and used, there are the following problems. That is, in such a fluid ejection device, elements for ejecting fluid are arranged corresponding to a plurality of nozzles arranged in this nozzle row, but a voltage is simultaneously applied to elements adjacent to each other along the longitudinal direction. Then, adjacent elements and inks in adjacent nozzles slightly affect each other, and there is a possibility that crosstalk occurs and an accurate discharge amount cannot be secured or the landing position is slightly shifted. This also applies to the spare nozzle row.

  An object of the fluid ejection device and the control method thereof according to the present invention is to extend the life of each nozzle and suppress crosstalk of the nozzle.

  The present invention adopts the following means in order to achieve the above-mentioned object.

The fluid ejection device of the present invention is
From a kth (k = 1, 2,..., N) nozzle belonging to each nozzle row, a predetermined number of nozzle rows in which n (n is an integer of 2 or more) nozzles that can discharge a predetermined fluid are arranged. A head in which each nozzle row is formed so that the discharged fluid lands at the same position on the target;
Moving means for relatively moving the head and the target;
Fluid ejection means formed in the head corresponding to each nozzle;
Storage means for storing a plurality of groups in which the nozzles belonging to at least two or more nozzle rows are combined for all the nozzles belonging to the predetermined number of nozzle rows so that the first to nth nozzles are aligned;
While controlling the moving means so that the head and the target move relative to each other, each group stored in the storage means is switched and set as a use target group at every predetermined timing, and belongs to the set use target group Control means for controlling the head to discharge a fluid from a nozzle to form a dot row on the target;
With
The nozzles included in each group stored in the storage unit correspond to fluid ejection units arranged at least every other one of the fluid ejection units arranged linearly along the longitudinal direction. This is a nozzle.

  In this fluid ejection device, while controlling the moving means so that the head and the target move relative to each other, each group stored in the storage means is switched at a predetermined timing to be set as a use target group, and the set use target group The head is controlled so as to form a dot row on the target by ejecting fluid from the nozzle belonging to. Here, the storage means stores a plurality of groups divided so that the nozzles belonging to at least two or more nozzle rows are combined for all the nozzles belonging to the predetermined number of nozzle rows so that the first to nth nozzles are aligned. Has been. In addition, the nozzles included in each group are fluid discharge means arranged at least every other (for example, every other or every other) of the liquid discharge means arranged linearly along the longitudinal direction. It is a corresponding nozzle. By doing so, the adjacent fluid discharge means are not used at the same time among the fluid discharge means arranged linearly along the longitudinal direction. Crosstalk can be suppressed.

  In addition, the fluid should just be what can be discharged from a nozzle, for example, the ink used for printing, the liquid agent used for a semiconductor manufacturing process, etc. are mentioned. The target is not limited as long as it can adhere to the fluid, and examples thereof include paper, cloth, a resin plate, and a metal plate. The moving means may be a means for moving the target with respect to the fixed head, or a means for moving the head with respect to the fixed target. It may be a means for moving the target in a direction orthogonal to the direction. The numerical value n is not particularly limited as long as it is an integer of 2 or more. For example, the numerical value n is determined to be about several tens to several thousand based on the resolution of the dots and the length of the nozzle row.

  In the fluid ejecting apparatus of the present invention, the fluid ejecting means may be a means including a piezoelectric element that deforms when a voltage is applied and discharges the fluid from the nozzle by increasing the pressure of the fluid in the nozzle. Good. When the adjacent piezoelectric elements arranged linearly along the longitudinal direction are used at the same time, the voltage value deviates from the original value due to the influence of the adjacent element or receives the vibration of the adjacent element. Since the fluid pressure may deviate from the original value, the significance of applying the present invention is high.

  In the fluid ejection device of the present invention, the head may include two nozzle rows. Three or more nozzle rows in which nozzles capable of ejecting the same fluid are arranged may be formed. However, this makes it easy to enlarge the head and increase the cost. Therefore, it is preferable to reduce the number of nozzle rows to two, that is, the minimum number, in order to reduce the size and cost of the head. In this case, the control means makes an odd number nozzle belonging to one of the two nozzle rows and an even number nozzle belonging to the other of the two nozzle rows into one group, and belongs to one of the two nozzle rows. The even-numbered nozzles and the odd-numbered nozzles belonging to the other of the two nozzle rows may be another group. In this way, grouping can be performed easily.

  In the fluid ejection device of the present invention, the nozzle rows may have the nozzles arranged in a staggered manner. In this case, since the nozzles are arranged in a zigzag pattern, that is, in a zigzag pattern as compared with the case where the nozzles are arranged in a straight line, it is possible to increase the density of the nozzles.

  In the fluid ejection device of the present invention, the control unit may switch each group for each target and set the group as the use target group. The timing for switching each group may be for each job, but if this is done, the time for which the same nozzle is continuously used becomes longer, and heat may accumulate in the head. On the other hand, if the target is switched for each target, the time for continuously using the same nozzle is shortened, and heat hardly accumulates in the head.

  In the fluid ejection device of the present invention, the head may be a line head formed so that the nozzle row has a length equal to or longer than the width of the target. When such a line head is adopted, the head becomes large, and there is a high possibility that the ejection operations of the nozzles influence each other through the fluid supply path. Therefore, the significance of applying the present invention is high.

The control method of the fluid ejection device of the present invention includes:
From a kth (k = 1, 2,..., N) nozzle belonging to each nozzle row, a predetermined number of nozzle rows in which n (n is an integer of 2 or more) nozzles that can discharge a predetermined fluid are arranged. A head in which each nozzle row is formed so that the ejected fluid is landed at the same position on the target, a moving means for moving the head and the target relative to each other, and an inside of the head corresponding to each nozzle A fluid ejection means formed on the fluid ejection means, comprising:
(A) A plurality of groups in which the nozzles belonging to at least two or more nozzle rows are combined for all the nozzles belonging to the predetermined number of nozzle rows so that the first to nth nozzles are aligned are stored in a predetermined storage unit. Memorizing step;
(B) While controlling the moving means so that the head and the target move relative to each other, each group stored in the storage means is switched at every predetermined timing to be set as a use target group, and the set use target Controlling the head to form a dot row on the target by ejecting fluid from nozzles belonging to a group;
Including
In the step (a), the nozzles included in each group stored in the storage unit are arranged at least every other one of the fluid discharge units arranged linearly along the longitudinal direction. The nozzle corresponds to the fluid discharge means.

  In this fluid ejection device control method, the moving means is controlled so that the head and the target move relative to each other, and each group stored in the storage means is switched at every predetermined timing to be set as a use target group. The head is controlled to form a dot row on the target by ejecting fluid from the nozzles belonging to the use target group. Here, the storage means stores a plurality of groups divided so that the nozzles belonging to at least two or more nozzle rows are combined for all the nozzles belonging to the predetermined number of nozzle rows so that the first to nth nozzles are aligned. Has been. Further, the nozzles included in each group are nozzles corresponding to the fluid ejecting means arranged at least every other one of the fluid ejecting means arranged linearly along the longitudinal direction. By doing so, the adjacent fluid discharge means are not used at the same time among the fluid discharge means arranged linearly along the longitudinal direction. Crosstalk can be suppressed. In such a control method, steps for realizing the functions and functions exhibited by the various configurations included in the fluid ejection device of the present invention described above may be added.

  Next, an embodiment embodying the present invention will be described. 1 is a cross-sectional view showing an outline of the configuration of an inkjet printer 20 according to the present embodiment, FIG. 2 is an explanatory view showing an outline of the configuration of a line head 22, and FIG. 3 is an explanatory view showing electrical connections of the inkjet printer 20. FIG. 4 is a perspective view including the AA cross section of FIG.

  As shown in FIG. 1, the inkjet printer 20 of the present embodiment includes a line head 22 that performs printing by ejecting ink droplets onto a recording sheet S conveyed from a paper feed tray 52, and a conveyance drive motor 62. A paper feeding mechanism 50 including a belt 60 spanned between a pair of driven conveying rollers 58 and 58 and a controller 70 (see FIG. 3) for controlling the entire inkjet printer 20 are provided.

  The line head 22 is formed in a substantially rectangular shape, and is fixed to the printer main body in a state where the longitudinal direction is orthogonal to the transport direction. The line head 22 is connected to an ink cartridge 24 that individually accommodates cyan (C), magenta (M), and yellow (Y) inks via a tube 26. As shown in FIG. 2, the line head 22 has a nozzle plate 28 on the bottom surface. The nozzle plate 28 has a first cyan nozzle row C1 in which n first cyan nozzles NC1 capable of discharging cyan (C) ink are arranged along the longitudinal direction, and can also discharge cyan (C) ink. A second cyan nozzle row C2 in which n second cyan nozzles NC2 are arranged, a first magenta nozzle row M1 in which n first magenta nozzles NM1 capable of ejecting magenta (M) ink are arranged, and magenta (M) A second magenta nozzle row M2 in which n second magenta nozzles NM2 capable of ejecting ink are arranged, a first yellow nozzle row Y1 in which n first yellow nozzles NY1 capable of ejecting yellow (Y) ink are arranged, and the like A second yellow nozzle row Y2 in which n second yellow nozzles NY2 capable of discharging yellow (Y) ink are arranged is formed. The lengths of the nozzle rows C1, C2, M1, M2, Y1, and Y2 are equal to or greater than the maximum width of the printable print paper. The numerical value n is a value determined based on the resolution of the dots and the length of the nozzle row, and is about several tens to several thousand (here, several hundreds). In this embodiment, black (K) is created by mixing colors of cyan (C), magenta (M), and yellow (Y), but a black (K) ink row may be provided separately.

  Here, the first cyan nozzle row C1 will be described as an example. When the first cyan nozzle row C1 is viewed along the longitudinal direction, the plurality of first cyan nozzles NC1 constituting the first cyan nozzle row C1 are staggered. It is arranged to be (zigzag). Specifically, the odd-numbered (# 1, 3, 5,...) First cyan nozzles NC1 are arranged in a line so that the pitch becomes a predetermined length L along the longitudinal direction, and the even-numbered (# 2, 4). , 6,...) Of the first cyan nozzles NC1 are arranged in a line parallel to the arrangement direction of the odd-numbered first cyan nozzles NC1 and the pitch is a predetermined length L, and adjacent odd-numbered first cyan nozzles. The pitch between NC1 and the even-numbered first cyan nozzle NC1 is half of the predetermined length L (L / 2). In the present embodiment, the predetermined length L is determined so that the dot has a resolution of 180 dpi, and the dots formed by the ink ejected from the odd-numbered first cyan nozzle NC1 and the even-numbered first cyan nozzle. Since printing is performed with the conveyance of the recording paper S so that dots formed by the ink ejected from the NC1 are arranged in a line, the resolution of the obtained printed matter is 360 dpi. Note that the resolution can be increased by appropriately shortening the predetermined length L. As shown in FIG. 4, the first cyan nozzle NC <b> 1 communicates with an ink chamber 34 </ b> C <b> 1 provided inside the line head 22. In the ink chamber 34C1, when a voltage is applied to the upper electrode UE and the lower electrode LE of the piezoelectric element 38C1 attached to the vibration plate 36 that forms the upper wall of the ink chamber 34C1, the piezoelectric element 38C1 is deformed and compresses the chamber volume. When the application of voltage is canceled, the piezoelectric element 38C1 is restored and the indoor volume is restored. Thereby, ink is ejected from the first cyan nozzle NC1. Such a piezoelectric element 38C1 is provided corresponding to each of the first cyan nozzles NC1. In this embodiment, as shown in FIG. 2, the piezoelectric elements 38C1 are arranged in two rows along the longitudinal direction of the line head 22, and the piezoelectric elements 38C1 in one row correspond to the odd-numbered first cyan nozzle NC1. The piezoelectric element 38C1 in the other row corresponds to the even-numbered first cyan nozzle NC1. The second cyan nozzle row C2 is formed in the same manner as the first cyan nozzle row C1 next to the first cyan nozzle row C1. That is, the position where the ink ejected from the kth (k = 1, 2,..., N) first cyan nozzle NC1 of the first cyan nozzle row C1 lands on the recording paper S and the second cyan nozzle row C2. The first and second cyan nozzle rows C1 and C2 are formed so that the ink discharged from the k-th second cyan nozzle NC2 lands on the recording paper S. As shown in FIG. 2, the piezoelectric elements 38C2 are arranged in two rows along the longitudinal direction of the line head 22, and the piezoelectric elements 38C2 in one row correspond to the odd-numbered second cyan nozzle NC2. The piezoelectric element 38C2 in the other row corresponds to the even-numbered second cyan nozzle NC2. The first and second magenta nozzle rows M1 and M2 and the first and second yellow nozzle rows Y1 and Y2 are formed in the same manner as the first and second cyan nozzle rows C1 and C2. Detailed description thereof is omitted here. For example, as described in Japanese Patent Application Laid-Open No. 2006-93312, such a line head 22 forms a piezoelectric film by a film forming technique, and divides the piezoelectric film into a shape corresponding to an ink chamber by lithography. Since it can be produced by a thin film formation process, high density nozzles can be realized at low cost.

  As shown in FIG. 1, the paper feed mechanism 50 includes a recording paper insertion port 54 into which the recording paper S placed on the paper feed tray 52 is inserted, and a recording paper S placed on the paper feed tray 52 through the line head. 22 and an endless belt 60 that is stretched between a pair of transport rollers 58 and 58 and transports the recording paper S by electrostatic suction or vacuum suction. The paper feeding mechanism 50 transports the recording paper S in a direction orthogonal to the direction in which the ink nozzle rows formed on the line head 22 are arranged. One of the pair of transport rollers 58, 58 is a drive roller driven by a drive motor 62, and the other is a driven roller that rotates as the drive roller rotates. The drive roller of the paper feed roller 56 and the pair of transport rollers 58, 58 is driven by a transport drive motor 62 via a gear mechanism (not shown).

  As shown in FIG. 3, the controller 70 is configured as a microprocessor centered on the CPU 72, and includes a ROM 74 that stores various processing programs, a RAM 76 that temporarily stores data and stores data, Data can be freely erased and written, and the contents are not lost even when the power is turned off, an interface (I / F) 78 for exchanging information with external devices, and an input / output port (not shown) I have. A signal relating to the position of the recording sheet S from a rotary encoder 64 attached to the drive motor 62 for conveyance is input to the controller 70 via an input port (not shown), and a print job output from the user PC 110 Etc. are input via the I / F 78. Further, the controller 70 supplies drive signals to the piezoelectric element drive circuits 39C1, 39C2, 39M1, 39M2, 39Y1, and 39Y2 for driving the piezoelectric elements 38C1, 38C2, 38M1, 38M2, 38Y1, and 38Y2 of the line head 22 and for conveying. A control signal to the drive motor 62 is output via an output port (not shown), and print status information to the user PC 110 is output via the I / F 78. The ROM 74 stores processing programs such as a print processing routine program described later. The RAM 76 is provided with a print buffer area. In the print buffer area, print data sent from the user PC 110 via the I / F 78 is temporarily stored.

  In this embodiment, the ink nozzles are divided into two groups A and B. FIG. 5 is an explanatory diagram showing an example in which the cyan nozzles NC1 and NC2 are divided into two groups A and B. FIG. As shown in FIG. 5 (a), the group A includes the first, fifth, ninth,... Of the odd first cyan nozzles NC1 in the first cyan nozzle row C1. In addition to the second, sixth,... First cyan nozzles NC1 arranged every other one of the 1 cyan nozzle NC1 and even-numbered first cyan nozzle NC1, the odd-numbered second cyan of the second cyan nozzle row C2. Third, seventh,..., Second cyan nozzles arranged alternately so as not to pair with the first cyan nozzle NC1 selected earlier among the nozzles NC2 (that is, not to select the same one in the order of arrangement) 4th, 8th,..., Second cyan nozzles NC2 arranged alternately so as not to be paired with the first cyan nozzle NC1 selected earlier among NC2 and even-numbered second cyan nozzles NC2 are included. This group A includes first and second magenta nozzles NM1, NM2 and first and second yellow nozzles NY1, NY2 which are selected in the same manner. On the other hand, as shown in FIG. 5B, the group B includes the first and second cyan nozzles NC1 and NC2, the first and second magenta nozzles NM1 and NM2, which are not selected in the group A, and the first and second. 2 yellow nozzles NY1, NY2 are included. For example, when cyan is taken as an example, the third, seventh,... First cyan nozzles NC1 and even-numbered first cyan nozzles NC1 arranged every other odd-numbered first cyan nozzle NC1 in the first cyan nozzle row C1. In addition to the fourth, eighth,... First cyan nozzles NC1 arranged in every other one of the cyan nozzles NC1, the first selected from the odd numbered second cyan nozzles NC2 of the second cyan nozzle row C2. The first cyan nozzle previously selected from the first, fifth, ninth,... Second cyan nozzles NC2 and even-numbered second cyan nozzles NC2 arranged alternately so as not to form a pair with the cyan nozzle NC1. Second, sixth,..., Second cyan nozzles NC2 arranged every other line so as not to form a pair with NC1 are included. By dividing into two groups A and B in this way, the same color ink nozzles belonging to the same group are aligned from the first to the nth. Information regarding which ink nozzles are included in each of these groups A and B is stored in the ROM 74 in advance.

  Next, the operation of the ink jet printer 20 of the present embodiment configured as described above will be described. FIG. 6 is a flowchart of the print control routine. When a print job is input from the user PC 110, the CPU 72 of the controller 70 reads a print control routine program from the ROM 74 and executes it. When the print control routine is started, the CPU 72 first sets a group of ink nozzles to be used (step S100). When the print control routine is executed for the first time after shipment from the factory, it is set to group A. However, when the print control routine has been executed in the past, it is set to a group different from the group last set in the previous printing. Subsequently, paper feed processing is executed (step S110). In the paper feed process, the paper feed roller 56 and the pair of transport rollers 58 and 58 are driven to rotate by driving the drive motor 62, and the print start position of the recording paper S placed on the paper feed tray 52 faces the line head 22. It is the process which conveys until it reaches the predetermined position. Next, the CPU 72 selects a nozzle (ejection target nozzle) that should eject ink based on the print data included in the print job from the nozzles included in the set group (step S120). For example, when the set group is group A, for cyan, the first cyan nozzle NC1 of the first, fifth, ninth,... And the first of the second, sixth,. A discharge target nozzle is selected from the third, seventh,..., Second cyan nozzle NC2, fourth, eighth,..., Second cyan nozzle NC2 of the cyan nozzle NC1, the second cyan nozzle row C2. Similarly, for magenta and yellow, the ejection target nozzle is selected. Further, when the set group is group B, for cyan, the third, seventh, eleventh,... First cyan nozzle NC1, fourth, eighth, twelfth,. ... Are selected from the first cyan nozzle NC1, the first cyan nozzle row C2, the second cyan nozzle NC2, the second cyan nozzle NC2, and the second cyan nozzle NC2. To do. Similarly, for magenta and yellow, the ejection target nozzle is selected.

  Subsequently, a control signal is sent to the piezoelectric element drive circuits 39C1, 39C2, 39M1, 39M2, 39Y1, and 39Y2 so that ink is ejected from the selected ejection target nozzle (step S130). Thereafter, it is determined whether or not printing for one page has been completed (step S140). If printing for one page has not been completed, the processes of steps S120 to S140 are executed again. During the repetition of steps S120 to S140, the pair of transport rollers 58 and 58 are rotated by driving the drive motor 62 to transport the recording paper S at a predetermined speed. The predetermined speed at which the recording paper S is conveyed is determined so that dots formed on the recording paper S are formed with a resolution of 360 dpi. Such processing is repeatedly executed, and when it is determined in step S140 that printing for one page has been completed, paper discharge processing is executed (step S150). The paper discharge process is a process of rotating the pair of transport rollers 58 and 58 by driving the drive motor 62 and discharging the printed recording paper S to a paper discharge tray (not shown). Subsequently, it is determined whether there is a next page to be printed (step S160). If there is a next page, the ink nozzle to be used is changed to a group different from the currently set group (step S170). Then, the process returns to step S110 again, and when there is no next page, this routine is terminated.

  Next, dots formed by such a print control routine will be described. FIG. 7 shows the elapsed time and the dots formed on the recording paper S when solid ink dots are formed on the entire surface of the recording paper S when the group of ink nozzles to be used is set to the group A. It is explanatory drawing showing these relationships. Here, the dot rows to be formed on the recording paper S are a total of six dot rows from the first row to the sixth row, and each dot row includes the first dot to the ninth dot. A total of 9 dots are lined up. Times T1 to T9 represent times each time the recording paper S is conveyed by one dot.

  At time T1, as shown in FIG. 7A, a voltage is applied to the piezoelectric element 38C1 corresponding to the first, fifth, ninth,... First cyan nozzle NC1 in the first cyan nozzle row C1, Ink is ejected from these first cyan nozzles NC1. Thereby, as shown in FIG. 7A, dots are formed on the first dot row of the recording paper S as stepping stones. At time T2, as shown in FIG. 7B, the first, fifth, ninth,... First cyan nozzle NC1 and the second, sixth,... First cyan in the first cyan nozzle row C1. A voltage is applied to the piezoelectric element 38C1 corresponding to the nozzle NC1, and ink is ejected from the first cyan nozzle NC1. The dots formed at that time are also shown in FIG. At time T3, as shown in FIG. 7C, the first, fifth, ninth,... First cyan nozzle NC1 and the second, sixth,. In addition to the piezoelectric element 38C1 corresponding to the nozzle NC1, a voltage is also applied to the piezoelectric elements 38C2 corresponding to the third, seventh,..., Second cyan nozzles NC2 in the second cyan nozzle row C2. Ink is discharged from the second cyan nozzles NC1 and NC2. The dots formed at that time are also shown in FIG. At time T4, as shown in FIG. 7 (d), the first cyan nozzle NC1 of the first, fifth, ninth,... And the second, sixth,. In addition to the piezoelectric element 38C1 corresponding to the nozzle NC1, it corresponds to the third, seventh,... Second cyan nozzle NC2 and the fourth, eighth,. A voltage is also applied to the piezoelectric element 38C2, and ink is ejected from the first and second cyan nozzles NC1 and NC2. The dots formed at that time are also shown in FIG.

  At subsequent times T5 and T6, as shown in FIGS. 7E and 7F, ink is ejected in the same manner as at time T4, and dots are formed on the recording paper S. At time T7, as shown in FIG. 7G, in addition to the piezoelectric element 38C1 corresponding to the second, sixth,... First cyan nozzle NC1 of the first cyan nozzle array C1, the second cyan nozzle array C2. Are applied to the piezoelectric element 38C2 corresponding to the third, seventh,... Second cyan nozzle NC2 and the fourth, eighth,... Second cyan nozzle NC2, and the first and second cyan nozzles. Ink is ejected from NC1 and NC2. The dots formed at that time are also shown in FIG. At time T8, as shown in FIG. 7 (h), the second cyan nozzle NC2 of the third, seventh,... And the second cyan nozzle NC2 of the fourth, eighth,. A voltage is applied to the corresponding piezoelectric element 38C2, and ink is ejected from the second cyan nozzle NC2. The dots formed at that time are also shown in FIG. At time T9, as shown in FIG. 7 (i), a voltage is applied to the piezoelectric element 38C2 corresponding to the fourth, eighth,... Ink is ejected from the two cyan nozzle NC2. The dots formed at that time are also shown in FIG. As described above, the dot rows from the first row to the sixth row are filled with dots formed by cyan ink.

  FIG. 8 shows the elapsed time and the dots formed on the recording paper S when solid ink dots are formed on the entire surface of the recording paper S when the group of ink nozzles to be used is set to the group B. It is explanatory drawing showing these relationships.

  At time T1, as shown in FIG. 8 (a), a voltage is applied to the piezoelectric element 38C1 corresponding to the third, seventh,... Ink is ejected from one cyan nozzle NC1. Thereby, as shown in FIG. 8A, dots are formed on the first dot row of the recording paper S as stepping stones. At time T2, as shown in FIG. 8B, the third, seventh,... First cyan nozzle NC1 and the fourth, eighth,. A voltage is applied to the corresponding piezoelectric element 38C1, and ink is ejected from the first cyan nozzle NC1. The dots formed at that time are also shown in FIG. At time T3, as shown in FIG. 8C, the third, seventh,... First cyan nozzle NC1 and the fourth, eighth,. In addition to the corresponding piezoelectric element 38C1, a voltage is also applied to the piezoelectric elements 38C2 corresponding to the first, fifth, ninth,..., Second cyan nozzles NC2 in the second cyan nozzle row C2. Ink is discharged from the second cyan nozzles NC1 and NC2. The dots formed at that time are also shown in FIG. At time T4, as shown in FIG. 8D, the third, seventh,... First cyan nozzle NC1 and the fourth, eighth,. In addition to the corresponding piezoelectric element 38C1, it corresponds to the first, fifth, ninth,... Second cyan nozzle NC2 and the second, sixth,. A voltage is also applied to the piezoelectric element 38C2, and ink is ejected from the first and second cyan nozzles NC1 and NC2. The dots formed at that time are also shown in FIG.

  At subsequent times T5 and T6, ink is ejected in the same manner as at time T4, and dots are formed on the recording paper S, as shown in FIGS. At time T7, as shown in FIG. 8G, in addition to the piezoelectric element 38C1 corresponding to the fourth, eighth,... First cyan nozzle NC1 in the first cyan nozzle array C1, the second cyan nozzle array C2. Are applied to the piezoelectric element 38C2 corresponding to the first, fifth, ninth,... Second cyan nozzle NC2 and the second, sixth,... Second cyan nozzle NC2. Ink is ejected from the two cyan nozzles NC1 and NC2. The dots formed at that time are also shown in FIG. At time T8, as shown in FIG. 8 (h), in the second cyan nozzle row C2, the first, fifth, ninth,... Second cyan nozzle NC2 and the second, sixth,. A voltage is applied to the piezoelectric element 38C2 corresponding to the nozzle NC2, and ink is ejected from the second cyan nozzle NC2. The dots formed at that time are also shown in FIG. At time T9, as shown in FIG. 8 (i), a voltage is applied to the piezoelectric element 38C2 corresponding to the second, sixth,... Ink is ejected from the two cyan nozzle NC2. The dots formed at that time are also shown in FIG. As described above, the dot rows from the first row to the sixth row are filled with the dots formed by the cyan ink using the cyan nozzles that are not used in the group A.

  Here, the correspondence between the components of the present embodiment and the components of the present invention will be clarified. The ink jet printer 20 of this embodiment corresponds to the fluid ejection device of the present invention, the line head 22 corresponds to the head, the paper feed mechanism 50 corresponds to the moving means, and the piezoelectric elements 38C1, 38C2, 38M1, 38M2, 38Y1, 38Y2 corresponds to the fluid discharge means, and the controller 70 corresponds to the control means. When the predetermined fluid is cyan ink, the first and second cyan nozzle arrays C1 and C2 correspond to nozzle arrays in which n nozzles capable of discharging the predetermined fluid are arranged, and the predetermined fluid is magenta. When ink is used, the first and second magenta nozzle arrays M1 and M2 correspond to nozzle arrays in which n nozzles capable of discharging a predetermined fluid are arranged, and when the predetermined fluid is yellow ink, The first and second yellow nozzles Y1, Y2 correspond to a nozzle row in which n nozzles capable of discharging a predetermined fluid are arranged. In the present embodiment, an example of the control method of the fluid ejection device of the present invention is also clarified by describing the operation of the ink jet printer 20.

  According to the ink jet printer 20 of the present embodiment described in detail above, since either one of the groups A and B is set as a target nozzle to form a dot row, it is linear along the longitudinal direction of the line head 22. Of the piezoelectric elements 38C1, 38C2, 38M1, 38M2, 38Y1, and 38Y2 that are adjacent to each other are not used at the same time. Therefore, crosstalk caused by simultaneously operating adjacent piezoelectric elements can be suppressed. Specifically, if adjacent ones of the piezoelectric elements 38C1, 38C2, 38M1, 38M2, 38Y1, and 38Y2 that are linearly arranged along the longitudinal direction of the line head 22 are used at the same time, the influence of the adjacent elements is affected. In response to this, the voltage value may deviate from the original value, or the fluid pressure in the nozzle may deviate from the original value due to adjacent vibrations. In this embodiment, the occurrence of such a problem is suppressed. be able to. In addition, since the first and second cyan nozzle rows C1 and C2 are arranged in a staggered pattern, i.e., zigzag, respectively, the density of the nozzles is increased as compared with the case where they are arranged in a straight line. Can be achieved. Furthermore, since each nozzle repeats ink ejection and ejection pause for each page, the driving frequency is halved compared to the case where ink ejection is performed each time, so that the life of the nozzle is extended and the line head 22 is Heat does not accumulate easily. Furthermore, when the line head 22 is adopted, the head becomes large, so that there is a high possibility that crosstalk occurs due to simultaneous operation of adjacent piezoelectric elements. Therefore, the significance of applying the present invention is high.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  For example, the groups A and B may be selected as follows. That is, in group A, for example, cyan, the first of the first, fifth, ninth,... Arranged in every other odd-numbered first cyan nozzle NC1 in the first cyan nozzle row C1. In addition to the fourth, eighth,... First cyan nozzles NC1 arranged every other one among the cyan nozzles NC1 and even-numbered first cyan nozzles NC1, the odd-numbered second cyan nozzles in the second cyan nozzle row C2. Among the NC2, the third cyan nozzle, the second cyan nozzle NC2, and the even-numbered second cyan nozzle NC2 that are arranged alternately so as not to pair with the first cyan nozzle NC1 selected earlier are selected earlier. The second, sixth,..., Second cyan nozzles NC2 are arranged so that they are not paired with the first cyan nozzle NC1. This group A includes first and second magenta nozzles NM1, NM2 and first and second yellow nozzles NY1, NY2 which are selected in the same manner. FIG. 9A is an explanatory diagram showing the relationship between the elapsed time and the dots formed on the recording paper S when solid cyan dots are formed on the entire surface of the recording paper S using the group A as the target nozzle. Shown in (i). On the other hand, the group B includes the first and second cyan nozzles NC1 and NC2, the first and second magenta nozzles NM1 and NM2, and the first and second yellow nozzles NY1 and NY2 that are not selected in the group A. For example, when cyan is taken as an example, the third, seventh,... First cyan nozzles NC1 and even-numbered first cyan nozzles NC1 arranged every other odd-numbered first cyan nozzle NC1 in the first cyan nozzle row C1. In addition to the second, sixth,... First cyan nozzles NC1 arranged in every other one of the cyan nozzles NC1, the first selected from the odd numbered second cyan nozzles NC2 of the second cyan nozzle row C2. The first cyan nozzle previously selected from the first, fifth, ninth,... Second cyan nozzles NC2 and even-numbered second cyan nozzles NC2 arranged alternately so as not to form a pair with the cyan nozzle NC1. 4th, 8th,..., Second cyan nozzles NC2 arranged every other line so as not to form a pair with NC1 are included. This group B includes first and second magenta nozzles NM1, NM2 and first and second yellow nozzles NY1, NY2 which are selected in the same manner. FIG. 10A is an explanatory diagram showing the relationship between the elapsed time and the dots formed on the recording paper S when solid cyan dots are formed on the entire surface of the recording paper S using this group B as the target nozzle. Shown in (i). Even when the groups A and B are selected in this way, the same effects as those of the above-described embodiment can be obtained.

  In the above-described embodiment, the line head 22 for color printing has been exemplified. However, it is also possible to form a line head for monochrome printing by making each ink nozzle row black nozzles that eject black (K) ink.

  In the embodiment described above, the nozzles included in each nozzle row are arranged in a zigzag pattern, but may be arranged linearly. Also in this case, each nozzle repeats ink ejection and ejection suspension each time one sheet of recording paper S is printed, so that the durability of the nozzles is improved.

  In the above-described embodiment, a method of ejecting ink by deforming the piezoelectric element and pressurizing ink in the ink chamber is employed, but generated by heating the ink in the ink chamber by a heating resistor (for example, a heater). A method of ejecting ink by pressurizing ink with bubbles may be employed.

  In the embodiment described above, two nozzle rows are formed for each color ink, but three or more rows may be formed. For example, when three nozzle rows are formed for each color ink, all nozzles belonging to the three nozzle rows are combined with nozzles belonging to at least two nozzle rows so that the first to nth nozzles are aligned. It may be divided into a plurality of groups. In this case, the nozzles included in each group are nozzles corresponding to every two of the piezoelectric elements that are linearly arranged along the longitudinal direction. Even in this case, the same effect as the above-described embodiment can be obtained.

  In the above-described embodiment, the line head 22 fixed to the printer main body is used. However, each ink nozzle row may be formed on a head mounted on a carriage that is movable in a direction orthogonal to the conveyance direction of the recording paper S. Good.

  In the above-described embodiment, the ink jet printer 20 has been exemplified. However, a multifunction printer or a facsimile apparatus including both a scanner device and a printing device may be used.

FIG. 2 is a cross-sectional view illustrating a schematic configuration of the inkjet printer 20. An explanatory view showing the outline of composition of line head 22. FIG. FIG. 3 is an explanatory diagram showing electrical connection of the inkjet printer. The perspective view containing the AA cross section of FIG. Explanatory drawing of cyan nozzles NC1 and NC2 included in groups A and B. 6 is a flowchart of a print control routine. Explanatory drawing showing the relationship between elapsed time when using group A, and a dot. Explanatory drawing showing the relationship between elapsed time when using group B, and a dot. Explanatory drawing showing the relationship between elapsed time and a dot when another group A is used. Explanatory drawing showing the relationship between elapsed time and a dot when another group B is used.

Explanation of symbols

20 Inkjet printer, 22 line head, 24 ink cartridge, 26 tube, 28 nozzle plate, 34C1 ink chamber, 36 diaphragm, 38C1, 38C2, 38M1, 38M2, 38Y1, 38Y2 piezoelectric element, 39C1, 39C2, 39M1, 39M2, 39Y1 , 39Y2 Piezoelectric element drive circuit, 50 paper feed mechanism, 52 paper feed tray, 54 recording paper insertion slot, 56 paper feed roller, 58 transport roller, 60 belt, 62 drive motor, 64 rotary encoder, 70 controller, 72 CPU, 74 ROM, 76 RAM, 77 flash memory, 78 I / F, 110 user PC, C1 first cyan nozzle row, C2 second cyan nozzle row, M1 first magenta nozzle row, M2 second magenta nozzle row, Y1 first i Yellow nozzle row, Y2 second yellow nozzle row, NC1 first cyan nozzle, NC2 second cyan nozzle, NM1 first magenta nozzle, NM2 second magenta nozzle, NY1 first yellow nozzle, NY2 second yellow nozzle, S recording paper, LE lower electrode, UE upper electrode.

Claims (8)

From a kth (k = 1, 2,..., N) nozzle belonging to each nozzle row, a predetermined number of nozzle rows in which n (n is an integer of 2 or more) nozzles that can discharge a predetermined fluid are arranged. A head in which each nozzle row is formed so that the discharged fluid lands at the same position on the target;
Moving means for relatively moving the head and the target;
Fluid ejection means formed in the head corresponding to each nozzle;
Storage means for storing a plurality of groups in which the nozzles belonging to at least two or more nozzle rows are combined for all the nozzles belonging to the predetermined number of nozzle rows so that the first to nth nozzles are aligned;
While controlling the moving means so that the head and the target move relative to each other, each group stored in the storage means is switched and set as a use target group at every predetermined timing, and belongs to the set use target group Control means for controlling the head to discharge a fluid from a nozzle to form a dot row on the target;
With
Nozzles included in each group stored in the storage means correspond to fluid ejection means arranged at least every other one of the fluid ejection means arranged linearly along the longitudinal direction. Is,
Fluid ejection device. The fluid ejecting means is a means including a piezoelectric element that deforms when a voltage is applied and ejects the fluid from the nozzle by increasing the pressure of the fluid in the nozzle.
The fluid ejection device according to claim 1. The head has two nozzle rows.
The fluid ejection device according to claim 1 or 2. The control means makes an odd-numbered nozzle belonging to one of the two nozzle rows and an even-numbered nozzle belonging to the other of the two nozzle rows as one group, and an even-numbered nozzle belonging to one of the two nozzle rows. An odd number nozzle belonging to the nozzle and the other of the two nozzle rows is made into another group,
The fluid ejection device according to claim 3. In each nozzle row, the nozzles are arranged in a staggered manner.
The fluid ejection device according to any one of claims 1 to 4. The control means switches each group for each target and sets the group to be used.
The fluid ejection device according to any one of claims 1 to 5. The head is a line head formed so that the nozzle row has a length equal to or longer than the width of the target.
The fluid ejection device according to claim 1. From a kth (k = 1, 2,..., N) nozzle belonging to each nozzle row, a predetermined number of nozzle rows in which n (n is an integer of 2 or more) nozzles that can discharge a predetermined fluid are arranged. A head in which each nozzle row is formed so that the ejected fluid is landed at the same position on the target, a moving means for moving the head and the target relative to each other, and an inside of the head corresponding to each nozzle A fluid ejection device comprising: a fluid ejection means formed on
(A) A plurality of groups in which the nozzles belonging to at least two or more nozzle rows are combined for all the nozzles belonging to the predetermined number of nozzle rows so that the first to nth nozzles are aligned are stored in a predetermined storage unit. Memorizing step;
(B) While controlling the moving means so that the head and the target move relative to each other, each group stored in the storage means is switched at every predetermined timing to be set as a use target group, and the set use target Controlling the head to form a dot row on the target by ejecting fluid from nozzles belonging to a group;
Including
In the step (a), the nozzles included in each group stored in the storage unit are arranged at least every other one of the fluid discharge units arranged linearly along the longitudinal direction. A nozzle corresponding to the fluid discharge means,
Control method of fluid ejection device.

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