inkjet printer

Abstract

To impact object droplets at an aimed position of a recording medium.SOLUTION: An ink jet printer 10 includes: a nozzle 23 discharging ink IR to a recording medium 11 to be carried in; a charge electrode 3 imparting electric charge to droplets ID at timing at which the ink IR discharged by the nozzle 23 and flying is split into the droplets ID in vibration with certain frequency; a deflection electrode 5 which deflects a flying direction of the charged droplets ID by operation of an electric field caused by voltage application and impacts the droplets ID to the recording medium 11; an aggregate determination part 43 which determines whether or not there is an aggregate G of droplets ID in a front column relative to object droplets T to be impacted to the recording medium 11 on the basis of inputted recorded information; and a charge quantity adjustment part 44 adjusting a charge quantity charged by the charge electrode 3 of the object droplets T on the basis of determination of the aggregate determination part 43.SELECTED DRAWING: Figure 3

Description

Technical Field

[0006] , ,

[0007] , ,

[0001] The present invention relates to an inkjet printer.

Background Art

[0002] In an inkjet printer, it is known to charge droplets ejected from nozzles, deflect the charged droplets by a deflection electrode, and attach them to a recording medium to record information on the recording medium (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a configuration in which a plurality of types of staircase wave data corrected according to the printed dots in the front row of the charge control target column are stored in a video RAM, and in the print control of the charge control target column, the dot data in the front row stored in a register is classified in a front row correction circuit, and the staircase wave data after distortion correction is selectively read out to generate a charging voltage.

[0004] By the way, in an inkjet printer, it is preferable to land a target droplet at a target position on a recording medium.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In consideration of the above facts, an object of the present invention is to land a target droplet at a target position on a recording medium.

Means for Solving the Problems

[0007] An inkjet printer according to a first aspect of the present invention includes: a nozzle that ejects ink toward a relatively moving recording medium; a charging unit that charges the droplets by imparting an electric charge to them at the timing when the ink ejected from the nozzle and flying splits into droplets by vibrations of a certain frequency; a deflection unit that deflects the flight direction of the charged droplets by the action of an electric field generated by the application of a voltage, causing the droplets to land on the recording medium; an aggregate determination unit that determines, based on input recording information, whether or not there is an aggregate of droplets in the front row for a target droplet to land on the recording medium; and a charge amount adjustment unit that adjusts the amount of charge applied to the target droplet by the charging unit based on the determination of the aggregate determination unit.

[0008] In an inkjet printer according to a second aspect of the present invention, in an inkjet printer according to a first aspect of the present invention, if the target impact position of the target droplet onto the recording medium is above the aggregate, the charge adjustment unit adjusts the charge amount to be above the target impact position.

[0009] In an inkjet printer according to a third aspect of the present invention, in an inkjet printer according to the first or second aspect of the present invention, if the target impact position of the target droplet onto the recording medium is below the aggregate, the charge adjustment unit adjusts the charge amount so that it is below the target impact position.

[0010] In an inkjet printer according to a fourth aspect of the present invention, in any one of the inkjet printers according to the first to third aspects of the present invention, the adjustment value adjusted by the charge amount adjustment unit is determined based on the target landing position of the target droplet on the recording medium.

[0011] In an inkjet printer according to a fifth aspect of the present invention, in an inkjet printer according to any one of the first to fourth aspects of the present invention, the charge amount adjustment unit adjusts the charge amount when the target landing position of the target droplet is within a predetermined distance from the target landing position of the front row aggregate. [Effects of the Invention]

[0012] In the inkjet printer according to the first aspect of the present invention, the amount of charge applied to the target droplet by the charging part is adjusted based on the determination of the aggregate determination unit. Therefore, if an aggregate flies in the front row, the amount of charge applied to the target droplet is adjusted. As a result, if the target droplet is attracted to the side where air resistance is reduced due to the flight of the aggregate of droplets in the front row, the landing position on the recording medium is corrected. Consequently, the target droplet can be landed at the desired position on the recording medium.

[0013] In the inkjet printer according to the second aspect of the present invention, if the target impact point of the target droplet on the recording medium is above the aggregate, the charge adjustment unit adjusts the charge amount to be above the target impact point. As a result, when the target droplet is pulled downwards by the flight of the aggregate of droplets in the front row, where air resistance is reduced, the impact point of the target droplet on the recording medium is corrected to be above the target impact point. Therefore, the droplet can be impacted at the target position on the recording medium.

[0014] In the inkjet printer according to the third aspect of the present invention, if the target impact point of the target droplet on the recording medium is below the aggregate, the charge adjustment unit adjusts the charge amount so that it is below the target impact point. As a result, when the target droplet is pulled upward due to the reduced air resistance caused by the flight of the aggregate of droplets in the front row, the impact point of the target droplet on the recording medium is corrected so that it is below the target impact point. Therefore, the droplet can be impacted at the target position on the recording medium.

[0015] In the inkjet printer according to the fourth aspect of the present invention, the adjustment value adjusted by the charge amount adjustment unit is determined based on the target landing position of the target droplet on the recording medium, thereby adjusting the charge amount so that target droplets with different flight paths land at the target landing position.

[0016] In the inkjet printer according to the fifth aspect of the present invention, when the target landing position of the target droplet is within a predetermined distance from the target landing position of the aggregate in the front row, the charge adjustment unit adjusts the charge amount so that when there is an influence on the flight of the aggregate in the front row, the charge amount of the target droplet is adjusted. Therefore, the charge amount of the target droplet is not adjusted more than necessary. As a result, unnecessary processing can be omitted.

Brief Description of Drawings

[0017] [Figure 1] It is a schematic diagram showing an inkjet printer according to this embodiment. [Figure 2] It is a diagram for explaining the operation of landing droplets on a recording medium by the inkjet printer according to this embodiment. [Figure 3] It is a block diagram showing the functional configuration of the inkjet printer of this embodiment. [Figure 4] It is a diagram showing the look-up table stored in the storage unit of the inkjet printer of this embodiment. [Figure 5] It is a diagram for explaining the aggregate determination unit of the inkjet printer of this embodiment and is a diagram showing the target landing position. [Figure 6] It is a diagram for explaining the aggregate determination unit of the inkjet printer of this embodiment and is a diagram showing the target landing position. [Figure 7] It is a diagram for explaining the aggregate determination unit of the inkjet printer of this embodiment and is a diagram showing the target landing position. [Figure 8] It is a flowchart showing the flow of processing by the inkjet printer of this embodiment. [Figure 9] It is a diagram for explaining the operation of the inkjet printer and is a diagram for explaining the case where the target droplet is below the aggregate in the front row. [Figure 10] It is a diagram for explaining the operation of the inkjet printer and is a diagram for explaining the case where the target droplet is above the aggregate in the front row.

Modes for Carrying Out the Invention

[0018] Hereinafter, the inkjet printer according to this embodiment will be described with reference to the drawings. In this embodiment, an example of a continuous inkjet printer that prints by continuously ejecting ink from a nozzle, deflecting only the droplets necessary for printing, and landing them on a recording medium will be described. The direction in which the recording medium 11 is conveyed is defined as the conveyance direction R, and the direction in which the droplets are deflected is defined as the deflection direction Y. The deflection direction Y is the upward direction perpendicular to the conveyance direction R. Also, the target droplet is referred to as the target droplet T, and the dot data of the target droplet is referred to as the target droplet data TD.

[0019] [Configuration of Inkjet Printer 10] As shown in FIG. 2, the inkjet printer 10 lands droplets (ink droplets) ID on a recording medium (for example, a packing box) 11 conveyed in the conveyance direction R by a belt conveyor 15 as a conveyance unit, thereby printing a character 12 (in FIG. 2, "A") as recording information on the recording medium 11.

[0020] As shown in FIG. 1, the inkjet printer 10 includes a gun 2, a charging electrode 3 as a charging unit, a detection electrode 4, a deflection electrode 5, a gutter 6, a pipe 7, pumps 8A and 8B, and a tank 9.

[0021] (Tank 9) The tank 9 stores ink IR. The ink IR is a conductive liquid ink. The ink IR stored in the tank 9 is supplied to the gun 2 through the pipe 7 by the pump 8A.

[0022] (Gun 2) The gun 2 injects the ink IR toward the recording medium 11 (see FIG. 2), and includes a gun body 21 and a nozzle 23.

[0023] The gun body 21 is equipped with an ultrasonic transducer 22 inside. The ultrasonic transducer 22 can be, for example, a piezoelectric element. The ultrasonic transducer 22 vibrates at a constant frequency due to alternating current. The nozzle 23 is attached to the tip of the gun body 21. The nozzle 23 can be a single nozzle.

[0024] (Charging electrode 3) The charging electrode 3 is positioned downstream of the gun 2 in the flight direction of the droplet ID. The charging electrode 3 charges the droplet ID at the timing when the ink IR ejected from the nozzle 23 and flying splits into droplet IDs due to vibrations of a certain frequency. Specifically, by applying a required positive voltage to the charging electrode 3, a negative charge corresponding to the applied voltage is induced at the tip of the ink column IP, and the tip is detached, forming a droplet ID with a charge corresponding to the applied voltage.

[0025] (Detection electrode 4) The detection electrode 4 is positioned downstream of the charging electrode 3 in the direction of flight of droplet ID. The detection electrode 4 detects the passage of the charged droplet ID.

[0026] (Deflection electrode 5) The deflection electrode 5 is positioned downstream of the detection electrode 4 in the flight direction of the droplet ID. The deflection electrode 5 deflects the flight direction of the charged droplet ID in the Y-axis direction (upward), perpendicular to the transport direction R, by the action of the electric field generated when a voltage is applied, causing the droplet ID to land on the recording medium 11. Specifically, by applying a predetermined voltage (a high voltage of several kV) to the deflection electrode 5, an electric field is generated between the two deflection electrodes 5. When the charged droplet ID passes through this electric field, it receives an electric force, and the flight direction of the droplet ID changes by an amount of deflection corresponding to the amount of charge of each droplet ID.

[0027] (Gutter 6) Gutter 6 is positioned downstream of the deflection electrode 5 in the direction of droplet ID's flight. Gutter 6 collects droplet ID that is not deflected by the deflection electrode 5. The collected droplet ID is supplied to tank 9 via pipe 7 by pump 8B.

[0028] [Inkjet printer 10 operation] In the inkjet printer 10 configured in this way, ink IR stored in tank 9 is pumped out of tank 9 by pump 8A and supplied to gun body 21 through pipe 7. The ink IR supplied to gun body 21 is ejected from the holes of nozzle 23 with vibrations added by ultrasonic transducer 22. The ink column IP ejected from the holes of nozzle 23 is separated into individual droplets ID by vibrations of a constant frequency added by ultrasonic transducer 22.

[0029] By applying a positive voltage to the charging electrode 3 in synchronization with the generation of continuous droplet IDs, a charge is imparted to specific droplet IDs. The charged droplet IDs then pass through the deflection electrode 5, where they are deflected in the deflection direction Y according to the amount of charge they possess, and land on the recording medium 11.

[0030] By changing the amount of deflection of the droplet ID, the position of the droplet ID upon impact with the recording medium 11 changes. As a result, the deflection of the droplet ID is repeated in sync with the transport of the recording medium 11, and a character ("A" in Figure 2) is printed as recording information.

[0031] Any droplets (ID) that do not land on the recording medium 11 are collected in the gutter 6 and supplied to the tank 9 by the pump 8B, allowing the ink (IR) to be reused.

[0032] [Inkjet Printer 10 Functional Configurations] Functionally, the inkjet printer 10 receives recording information input to the input unit 30, which is then input to the control unit 40. The processed information processed by the control unit 40 is then output to the charged electrode 3.

[0033] The input unit 30 is a terminal into which recording information is input, and can be, for example, a touch panel or a tablet. The recording information input to the input unit 30 is input to the control unit 40.

[0034] The control unit 40 includes a storage unit 41, an input information acquisition unit 42, a collection determination unit 43, and a charge amount adjustment unit 44.

[0035] (Storage unit 41) The memory unit 41 stores the lookup table LUT and the program P.

[0036] As shown in Figure 4, the lookup table (LUT) stores an address, a pattern, and a judgment value. For each input pattern, the judgment value is assigned as an output value and read via the address.

[0037] The address can be, for example, 256 different values ​​in binary, ranging from "00000000" to "11111111". The patterns are all the patterns in which droplet data is filled into frame F, which will be described later. The determination includes information on the presence or absence of aggregate G (see Figure 5) for each pattern, and the position information of the target droplet data TD relative to aggregate G.

[0038] The lookup table LUT is stored with a different address for each row. For example, different lookup table LUTs are provided for the first and second rows shown in Figure 5.

[0039] Program P includes a program that adjusts the amount of charge according to the judgment result.

[0040] (Input information acquisition unit 42) The input information acquisition unit 42 acquires the recorded information entered into the input unit 30.

[0041] (Aggregation determination unit 43) The aggregate determination unit 43 determines, based on the recorded information acquired by the input information acquisition unit 42, whether or not there is an aggregate G of droplets in the front row relative to the target droplet T to be deposited on the recording medium 11. The aggregate determination unit 43 also determines, based on the recorded information acquired by the input information acquisition unit 42, whether or not the target droplet T to be deposited on the recording medium 11 is above the aggregate G of droplets in the front row. The aggregate G is an aggregate of droplets in the front row of the target droplet T, located at a predetermined distance from the target droplet T.

[0042] Specifically, as shown in Figure 5, the aggregate determination unit 43 generates dot data based on the recorded information acquired by the input information acquisition unit 42. The dot data is data indicating the target impact position of the droplet ID. Here, the dot data of the target droplet T is referred to as the target droplet data TD.

[0043] The aggregate determination unit 43 generates a frame F in the first column, which is the front row of the target droplet data TD. The frame F consists of multiple cells (9 cells labeled "0" to "8" in Figure 5) arranged in the column direction (vertical direction) with the target droplet data TD at its center.

[0044] The aggregate determination unit 43 refers to the lookup table LUT shown in Figure 4 and determines that "aggregate G exists" if four or more cells from "0" to "8" are filled with droplet data. The aggregate determination unit 43 refers to the lookup table LUT and determines that "the target droplet T is above aggregate G" if four or more cells from "0" to "4" are filled with droplet data. The aggregate determination unit 43 refers to the lookup table LUT and determines that "the target droplet T is below aggregate G" if four or more cells from "4" to "8" are filled with droplet data.

[0045] In Figure 5, cells "5" through "8" are filled with droplet data D in the first column. Therefore, in the example in Figure 5, the aggregate determination unit 43 can refer to the lookup table LUT and read the determination contents, "aggregate G exists" and "the target droplet T is above aggregate G," via the address. In other words, the aggregate determination unit 43 determines that "aggregate G exists" and that "the target droplet T is above aggregate G."

[0046] In Figure 6, cells "0" through "4" are filled with droplet data D in the second column. Therefore, in the example in Figure 6, the aggregate determination unit 43 can refer to the lookup table LUT and read the determination contents, "aggregate G exists" and "the target droplet T is below aggregate G," via the address. In other words, the aggregate determination unit 43 determines that "aggregate G exists" and that "the target droplet T is below aggregate G."

[0047] In Figure 7, the cells labeled "7" and "8" are filled with droplet data D from the first column. Therefore, in the example in Figure 7, the aggregate determination unit 43 can refer to the lookup table LUT and read the determination that "there is no aggregate G" via the address. In other words, the aggregate determination unit 43 determines that "there is no aggregate G".

[0048] (Charge amount adjustment unit 44) The charge amount adjustment unit 44 adjusts the amount of charge applied to the target droplet T by the charging electrode 3 based on the determination of the aggregate determination unit 43.

[0049] Specifically, the charge adjustment unit 44 executes the program P associated with the determination content via the address read by the aggregate determination unit 43.

[0050] The charge amount adjustment unit 44 adjusts the amount of charge applied to the charging electrode 3 so that it is above the target impact point of the target droplet T onto the recording medium 11, when the target impact point is above the aggregate G.

[0051] The charge amount adjustment unit 44 adjusts the amount of charge applied to the charging electrode 3 so that it is below the target impact point of the target droplet T onto the recording medium 11, when the target impact point is below the aggregate G.

[0052] The charge amount adjustment unit 44 adjusts the amount of charge applied to the charging electrode 3 when the target impact position of the target droplet T is within a predetermined distance from the target impact position of the front row aggregate G. For example, as shown in Figure 7, if the squares "4", "5", and "6" are not filled with the droplet data D in the first row, the deviation of the impact position of the target droplet T is small, so it is not necessary to adjust the amount of charge applied to the charging electrode 3.

[0053] The charge adjustment unit 44 adjusts the amount of charge applied to the charging electrode 3 for the aggregate G within a predetermined period (for example, 400 μseconds) from the timing of the ejection of the target droplet T. This predetermined period will vary as appropriate depending on various requirements such as the volume of the droplet, the velocity of the droplet, and the font size.

[0054] Since the lookup table LUT stores each row with a different address, the adjustment value adjusted by the charge amount adjustment unit 44 is determined based on the target landing position of the target droplet T on the recording medium 11.

[0055] [Processing flow using inkjet printer 10] As shown in Figure 8, when the inkjet printer 10 starts processing, the input information acquisition unit 42 acquires the recorded information input to the input unit 30 (step S101).

[0056] Next, the aggregate determination unit 43 determines, based on the recorded information acquired by the input information acquisition unit 42, whether or not there is an aggregate of droplets G in the front row for the target droplet T to be deposited on the recording medium 11 (step S102). If it is determined that there is an aggregate of droplets G in the front row (YES in step S102), the process proceeds to step S103. On the other hand, if it is determined that there is no aggregate of droplets G in the front row (NO in step S102), the process ends.

[0057] In step S103, the aggregate determination unit 43 determines, based on the recorded information acquired by the input information acquisition unit 42, whether the target droplet T to be deposited on the recording medium 11 is above the aggregate G of droplets in the front row. If it is determined that the target droplet T to be deposited on the recording medium 11 is above the aggregate G of droplets in the front row (YES in step S103), the process proceeds to step S104. On the other hand, if it is determined that the target droplet T to be deposited on the recording medium 11 is below the aggregate G of droplets in the front row (NO in step S103), the process proceeds to step S105.

[0058] In step S104, the charge adjustment unit 44 adjusts the amount of charge accumulated on the charging electrode 3 so that it is above the target impact point, and then terminates the process.

[0059] In step S105, the charge adjustment unit 44 adjusts the amount of charge accumulated on the charging electrode 3 so that it is below the target impact position, and then terminates the process.

[0060] [Effect] Incidentally, if droplets fly as a group in the front row, the target droplets in the next row will be attracted to the side where the air resistance is reduced by the flight of the droplet group in the front row.

[0061] Specifically, as shown in Figure 9(B), when the target droplet data TD is located below the front row aggregate G, the flight of the front row aggregate G generates airflow, and the flight path of the target droplet T is pulled upwards compared to when there is no aggregate G in the front row, as shown in Figure 9(A). As a result, as shown in Figure 9(B), the target droplet T that lands on the recording medium 11 is shifted upwards from the target position.

[0062] As shown in Figure 10(B), when the target droplet data TD is above the front row aggregate G, the flight of the front row aggregate G generates airflow, and the flight path of the target droplet T is pulled downwards compared to when there is no aggregate G in the front row, as shown in Figure 10(A). As a result, as shown in Figure 10(B), the target droplet T that lands on the recording medium 11 is shifted downwards from the target position.

[0063] Therefore, if the aggregate G flies in the front row, there is a problem in that the target droplet T cannot land at the target position on the recording medium 11.

[0064] The inkjet printer 10 of this embodiment includes a nozzle 23 that ejects ink IR toward a transported recording medium 11, a charging electrode 3 that charges droplet IDs at the timing when the ink IR ejected from the nozzle 23 and flying splits into droplet IDs due to vibrations of a certain frequency, a deflection electrode 5 that deflects the flight direction of the charged droplet IDs by the action of an electric field generated by the application of voltage, causing the droplet IDs to land on the recording medium 11, an aggregate determination unit 43 that determines the presence or absence of an aggregate G of droplet IDs in the front row for a target droplet T to land on the recording medium 11 based on input recording information, and a charge amount adjustment unit 44 that adjusts the amount of charge applied to the target droplet T by the charging electrode 3 based on the determination of the aggregate determination unit 43 (see Figure 3).

[0065] Based on the determination of the aggregate determination unit 43, the amount of charge applied to the target droplet T by the charging electrode 3 is adjusted. If an aggregate G flies in the front row, the amount of charge applied to the target droplet T is adjusted. Therefore, if the target droplet T is attracted to the side where the air resistance is reduced due to the flight of the aggregate G of droplet ID in the front row, the impact position on the recording medium 11 is corrected. As a result, the target droplet T can be made to land at the target position on the recording medium 11.

[0066] In the inkjet printer 10 of this embodiment, if the target impact point of the target droplet T onto the recording medium 11 is above the aggregate G, the charge amount adjustment unit 44 adjusts the charge amount so that it is above the target impact point.

[0067] As a result, if the target droplet T is pulled downwards by the flight of the cluster G of droplets ID in the front row, where air resistance is reduced, the impact position of the target droplet T on the recording medium 11 is corrected to be higher than the intended impact position. Therefore, droplet ID can be made to land at the intended position on the recording medium 11.

[0068] In the inkjet printer 10 of this embodiment, if the target impact point of the target droplet T onto the recording medium 11 is below the aggregate G, the charge amount adjustment unit 44 adjusts the charge amount so that it is below the target impact point.

[0069] As a result, if the target droplet T is pulled upward due to the reduced air resistance caused by the flight of the cluster G of droplets ID in the front row, the impact position of the target droplet T on the recording medium 11 is corrected to be lower than the intended impact position. Therefore, droplet ID can be made to land at the intended position on the recording medium 11.

[0070] Incidentally, if the target droplet T lands on the recording medium 11 at a different position, its flight path will also differ. Different flight paths result in different influences from the preceding aggregate G. Therefore, if the same amount of charge is adjusted when the landing position on the recording medium 11 differs, there is a problem that the target droplet T will deviate from the intended landing position.

[0071] In the inkjet printer 10 of this embodiment, the adjustment value adjusted by the charge amount adjustment unit 44 is determined based on the target landing position of the target droplet T on the recording medium 11.

[0072] The adjustment value adjusted by the charge amount adjustment unit 44 is determined based on the target impact position of the target droplet T onto the recording medium 11, thereby adjusting the charge amount so that target droplets T with different flight paths hit the target impact position.

[0073] In the inkjet printer 10 of this embodiment, the charge amount adjustment unit 44 adjusts the charge amount when the target landing position of the target droplet T is within a predetermined distance from the target landing position of the front row aggregate G.

[0074] When the target impact point of the target droplet T is within a predetermined distance from the target impact point of the front row aggregate G, the charge adjustment unit 44 adjusts the charge amount so that the charge amount of the target droplet T is adjusted when there is an influence from the flight of the front row aggregate G. Therefore, the charge amount of the target droplet T is not adjusted more than necessary. As a result, the burden on the control unit 40 can be reduced by eliminating unnecessary processing.

[0075] The inkjet printer of the present invention has been described above based on the above embodiments. However, the specific configuration is not limited to these embodiments, and changes to the design are permitted as long as they do not deviate from the gist of the invention as described in each claim of the patent claims.

[0076] In the above embodiment, the aggregate determination unit 43 showed an example in which nine cells are formed in the frame F. However, the number of cells in the frame is not limited to this embodiment.

[0077] In the above embodiment, the aggregate determination unit 43 determined that "aggregate G exists" when four or more cells were filled with droplet data D. However, the criteria used by the aggregate determination unit to determine "aggregate G exists" are not limited to this embodiment and can be changed as appropriate.

[0078] In the above embodiment, an example was shown where the droplet deflection direction is upward. However, the droplet deflection direction may be downward, upward and downward, or in any direction within 360°.

[0079] In the above embodiment, an example was shown where processing by the inkjet printer 10 is performed by embedded software. However, processing by the inkjet printer is not limited to this embodiment.

[0080] In the above embodiment, an example was shown in which the determination content is stored in the lookup table LUT. However, the lookup table may also store adjustment values ​​for adjusting the amount of charge that is applied to the target droplet T by the charging electrode 3.

[0081] In the above embodiment, the inkjet printer 10 was shown to deposit droplet IDs onto a recording medium 11 that was being transported in the transport direction R by a belt conveyor 15. However, the inkjet printer may also deposit droplets onto a fixed recording medium by moving the gun.

[0082] In the above embodiment, an example was shown in which droplet ID having a charge amount corresponding to the applied voltage is formed by applying a positive voltage to the charging electrode 3. However, droplets having a charge amount corresponding to the applied voltage may also be formed by applying a negative voltage to the charging electrode. [Explanation of Symbols]

[0083] 3. Charged electrode (an example of a charged part) 5 Deflection electrode (example of deflection part) 10 Inkjet Printers 11 Recording media 23 nozzles 43 Aggregate determination section 44 Charge amount adjustment unit ID droplet R Conveying direction T Target droplet

Claims

1. A nozzle that ejects ink toward a recording medium that is moving relatively, A charging unit that charges the ink droplets by imparting an electric charge to them at the moment when the ink ejected from the nozzle and flying through the air splits into droplets due to vibrations of a certain frequency, A deflection unit that deflects the flight direction of the charged droplet by the action of an electric field generated by the application of voltage, causing the droplet to land on the recording medium, Based on the input recording information, an aggregate determination unit determines whether or not there is an aggregate of droplets in the front row for the target droplet to be deposited on the recording medium, Based on the determination of the aggregate determination unit, the charge amount adjustment unit adjusts the amount of charge that the target droplet is charged by the charging unit, An inkjet printer equipped with [a specific feature].

2. If the target droplet's intended impact point on the recording medium is above the aggregate, the charge adjustment unit adjusts the charge amount so that it is above the intended impact point. The inkjet printer according to claim 1.

3. If the target droplet's intended impact point on the recording medium is below the aggregate, the charge adjustment unit adjusts the charge amount so that it is below the intended impact point. The inkjet printer according to claim 1.

4. The adjustment value adjusted by the charge adjustment unit is determined based on the target impact position of the target droplet onto the recording medium. The inkjet printer according to claim 1.

5. If the target impact point of the aforementioned droplet is within a predetermined distance from the target impact point of the front row aggregate, the charge adjustment unit adjusts the charge amount. The inkjet printer according to claim 1.

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