JP2021030520A - Inkjet printer and control method for inkjet printer - Google Patents

Abstract

To provide an inkjet printer capable of extending the service life of an inkjet head, although clogging can be inhibited in a nozzle which stops to discharge ink droplets at a prescribed timing during printing.SOLUTION: In an inkjet printer 1, an inkjet head 3 comprises a plurality of discharge energy generating elements for discharging ink droplets from a plurality of nozzles. In order to prevent the plurality of nozzles from clogging, a maintenance unit 10 is installed at a maintenance position MP separated from a printing area PA in the main scanning direction. In a meniscus vibration operation, the discharge energy generating elements are driven in order to vibrate a meniscus of the ink inside the nozzles, without discharging ink droplets from the nozzles. A control unit 6 of the inkjet printer 1 implements the meniscus vibration operation only before moving the inkjet head 3 having moved to the maintenance position MP, to the printing area PA.SELECTED DRAWING: Figure 1

Description

The present invention relates to an inkjet printer including an inkjet head that ejects ink droplets. The present invention also relates to a method for controlling an inkjet printer including an inkjet head that ejects ink droplets.

Conventionally, a piezo type inkjet head used in an inkjet printer is known (see, for example, Patent Document 1). The inkjet head described in Patent Document 1 includes a piezoelectric element that ejects ink droplets from a nozzle. In this inkjet head, in a nozzle in which ink droplets are not ejected at a predetermined timing during printing of a printing medium, the piezoelectric element is vibrated to the extent that ink droplets are not ejected from the nozzles to cause ink meniscus in the nozzles. It is vibrating slightly. Therefore, in this inkjet head, it is possible to suppress an increase in the viscosity of the ink in the nozzle in which the ejection of ink droplets is stopped, and to suppress clogging of the nozzle.

Japanese Unexamined Patent Publication No. 2013-14130

In the inkjet head described in Patent Document 1, as described above, in a nozzle in which ink droplets are not ejected at a predetermined timing during printing, the piezoelectric element is vibrated to such an extent that ink droplets are not ejected from the nozzle. Since the ink meniscus is slightly vibrated in the ink, it is possible to suppress the increase in the viscosity of the ink in the nozzle that has stopped ejecting ink droplets and suppress the clogging of the nozzle. There is. On the other hand, in this inkjet head, in the nozzle in which the ejection of ink droplets is stopped, the piezoelectric element is constantly vibrated to slightly vibrate the ink meniscus in the nozzle, so that the life of the piezoelectric element is shortened. As a result, the life of the inkjet head may be shortened.

Therefore, an object of the present invention is to extend the life of an inkjet head even if it is possible to suppress clogging of nozzles that stop ejecting ink droplets at a predetermined timing during printing. To provide a printer. Another object of the present invention is that the life of the inkjet head can be extended even if it is possible to suppress clogging of the nozzles that stop ejecting ink droplets at a predetermined timing during printing. The purpose is to provide a control method for an inkjet printer.

In order to solve the above problems, the inventor of the present application has conducted various studies. Specifically, the inventor of the present application ejects ink droplets even if the operation of vibrating the meniscus of the ink in the nozzle is not always performed in the nozzle in which the ejection of ink droplets is stopped at a predetermined timing during printing. We investigated various measures that can suppress the clogging of the idle nozzles.

As a result, the inventor of the present application drops ink from the nozzle of the inkjet head before moving the inkjet head, which has been moved to the maintenance position outside the printing area where printing by the inkjet head is performed in the main scanning direction, to the printing area. If the meniscus vibration operation that vibrates the ink meniscus in the nozzle without ejecting is performed, printing is being performed even if the meniscus vibration operation is not performed in the nozzle that pauses the ejection of ink droplets at a predetermined timing during printing. It has been found that it is possible to suppress clogging of a nozzle that has stopped ejecting ink droplets at a predetermined timing.

The inkjet printer of the present invention is based on such a new finding. In an inkjet printer that ejects ink droplets for printing, an inkjet head in which a plurality of nozzles for ejecting ink droplets are formed and an inkjet head are mounted. A plurality of inkjet heads are provided, including a carriage to be printed, a carriage drive mechanism for reciprocating the carriage in the main scanning direction, a maintenance unit for preventing clogging of a plurality of nozzles, and a control unit for controlling an inkjet printer. If a plurality of ejection energy generating elements for ejecting ink droplets from each of the nozzles of the above are provided and the area where printing by the inkjet head is performed in the main scanning direction is set as the printing area, the maintenance unit can be used from the printing area in the main scanning direction. Assuming that the operation of vibrating the meniscus of the ink in the nozzle without ejecting ink droplets from the nozzle by driving the ejection energy generating element, which is installed at the off-maintenance position, is the meniscus vibration operation, the control unit moves to the maintenance position. It is characterized in that the meniscus vibration operation is performed only before the moving inkjet head is moved to the print area.

Further, the control method of the inkjet printer of the present invention is based on the above-mentioned new findings, and includes an inkjet head in which a plurality of nozzles for ejecting ink droplets are formed, a carriage on which the inkjet head is mounted, and a carriage. Equipped with a carriage drive mechanism that reciprocates in the main scanning direction and a maintenance unit for preventing clogging of a plurality of nozzles, the inkjet head has a plurality of ejection energies for ejecting ink droplets from each of the plurality of nozzles. Assuming that the area in which the generation element is provided and printing by the inkjet head is performed in the main scanning direction is the printing area, the maintenance unit is a control method of an inkjet printer installed at a maintenance position outside the printing area in the main scanning direction. Therefore, if the operation of driving the ejection energy generating element to vibrate the meniscus of the ink in the nozzle without ejecting ink droplets from the nozzle is the meniscus vibration operation, the inkjet head that has moved to the maintenance position is moved to the print area. It is characterized in that the meniscus vibration operation is performed only before moving.

In the present invention, the meniscus vibration that drives the ejection energy generating element to vibrate the meniscus of the ink in the nozzle without ejecting ink droplets from the nozzle before moving the inkjet head that has been moved to the maintenance position to the printing area. It is working. Therefore, in the present invention, even if the meniscus vibration operation is not performed in the nozzle that pauses the ejection of ink droplets at a predetermined timing when printing is performed in the printing area, the ink droplets are discharged at a predetermined timing during printing. It is possible to suppress clogging of the nozzle that has stopped discharging.

Further, in the present invention, the meniscus vibration operation is performed only before the inkjet head that has been moved to the maintenance position is moved to the print area, and ink droplets are ejected at a predetermined timing when printing is performed in the print area. The meniscus vibration operation is not performed in the nozzle that is inactive. Therefore, in the present invention, it is possible to reduce the frequency with which the discharge energy generating element is driven. Therefore, in the present invention, it is possible to extend the life of the ejection energy generating element, and as a result, it is possible to extend the life of the inkjet head. That is, in the present invention, it is possible to extend the life of the inkjet head even if it is possible to suppress clogging of the nozzles that have stopped ejecting ink droplets at a predetermined timing during printing.

In the present invention, the control unit performs a post-vibration flushing operation in which the ejection energy generating element is driven to forcibly eject ink droplets from the nozzle after the meniscus vibration operation is performed and before the inkjet head is moved to the printing area. It is preferable to do so. According to the study of the inventor of the present application, with this configuration, the ink is ink at a predetermined timing during printing even if the meniscus vibration operation is not performed at the nozzle in which the ejection of ink droplets is stopped at a predetermined timing during printing. It becomes possible to effectively suppress the clogging of the nozzle in which the ejection of droplets is stopped.

In the present invention, for example, the control unit drives the ejection energy generating element to forcibly eject ink droplets from the nozzle before the meniscus vibration operation is performed in the state where the inkjet head is arranged at the maintenance position. Flushing operation is performed.

Further, in the present invention, for example, the maintenance unit includes a cap member for covering the nozzle surface of the inkjet head in which a plurality of nozzles are arranged from below, and the cap member covers the nozzle surface from below. It is possible to move between the cap position and the retracted position where the cap member retracts so as to move away from the nozzle surface, and the control unit moves the inkjet head to the maintenance position and caps the cap member placed in the retracted position. Before returning the inkjet head moved to the position and covering the nozzle surface from below with the cap member and then returning to the print area, the pre-vibration flushing operation is performed, and when the pre-vibration flushing operation is completed, The cap member arranged at the cap position is moved to the retracted position at a predetermined timing before the inkjet head moved to the maintenance position is returned to the printing area, and then the meniscus vibration operation is performed.

In the present invention, for example, the maintenance unit includes a cap member for covering the nozzle surface of the inkjet head in which a plurality of nozzles are arranged from below, and the cap member is a cap position where the cap member covers the nozzle surface from below. It is possible to move between the cap member and the retracted position where the cap member retracts so as to move away from the nozzle surface, and the control unit keeps the cap member in the retracted position even after moving the inkjet head to the maintenance position. At the same time, before returning the inkjet head moved to the maintenance position to the printing area, the meniscus vibration operation is performed without performing the pre-vibration flushing operation in which the ejection energy generating element is driven to forcibly eject ink droplets from the nozzles. You may go.

In the present invention, assuming that the drive frequency of the ejection energy generating element when ink droplets are continuously ejected from the nozzle in the shortest cycle during printing is the maximum drive frequency, the control unit performs the meniscus vibration operation at the maximum drive frequency. It is preferable to drive the discharge energy generating element with. With such a configuration, it becomes possible to facilitate the control of the inkjet printer when performing the meniscus vibration operation.

In the present invention, for example, in an inkjet printer, printing in the first print mode in which the ejection energy generating element is driven based on the first maximum drive frequency, which is a predetermined maximum drive frequency, and a frequency higher than the first maximum drive frequency. Printing in the second print mode in which the ejection energy generating element is driven based on the second maximum drive frequency, which is the maximum drive frequency, is possible, and the control unit prints in the first print mode in the print area. In the immediately preceding meniscus vibration operation, the discharge energy generating element is driven at the first maximum drive frequency, and in the meniscus vibration operation immediately before printing in the second print mode is performed in the print area, the discharge energy generating element is driven at the second maximum drive frequency. To drive.

In the present invention, the inkjet head ejects, for example, ultraviolet curable ink. In this case, since the viscosity of the ink is less likely to increase over time as compared with the case where the ink ejected from the inkjet head is a water-based ink, the ejection of ink droplets is stopped at a predetermined timing during printing. Even if the meniscus vibration operation is not performed on the nozzle, it becomes easy to suppress the clogging of the nozzle that has stopped ejecting ink droplets.

As described above, in the present invention, it is possible to extend the life of the inkjet head even if it is possible to suppress clogging of the nozzles that stop ejecting ink droplets at a predetermined timing during printing. Become.

It is a schematic diagram for demonstrating the schematic structure of the inkjet printer which concerns on embodiment of this invention. It is the schematic for demonstrating the structure of the inkjet head shown in FIG. It is a figure for demonstrating an example of the waveform of the voltage applied to the piezoelectric element from the control part shown in FIG. It is a flowchart for demonstrating an example of the control method of the inkjet printer shown in FIG.

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

(Configuration of inkjet printer)
FIG. 1 is a schematic diagram for explaining a schematic configuration of an inkjet printer 1 according to an embodiment of the present invention. FIG. 2 is a schematic view for explaining the configuration of the inkjet head 3 shown in FIG. FIG. 3 is a diagram for explaining an example of the waveform of the voltage applied from the control unit 6 shown in FIG. 2 to the piezoelectric element 11.

The inkjet printer 1 of this embodiment (hereinafter referred to as "printer 1") is, for example, a commercial inkjet printer, which ejects ink droplets to print on a printing medium 2 such as paper. The printer 1 has an inkjet head 3 (hereinafter, referred to as “head 3”) that ejects ink droplets toward a print medium 2, a carriage 4 on which the head 3 is mounted, and a carriage 4 in a main scanning direction (FIG. 1). A carriage drive mechanism 5 for reciprocating in the Y direction of the printer 1 and a control unit 6 for controlling the printer 1 are provided.

Further, the printer 1 raises and lowers the platen 8 on which the print medium 2 at the time of printing is placed, the guide rail 9 for guiding the carriage 4 in the main scanning direction, and the print medium 2 arranged on the platen 8. It is provided with a medium feed mechanism (not shown) for feeding in a sub-scanning direction (X direction in FIG. 1) orthogonal to the direction and the main scanning direction. Further, the printer 1 is provided with a maintenance unit 10 for preventing clogging of a plurality of nozzles 3a, which will be described later, formed on the head 3. The printer 1 may include a table on which the print medium 2 is placed and a table drive mechanism for moving the table in the sub-scanning direction, instead of the platen 8 and the medium feed mechanism.

The head 3 is arranged above the platen 8. The head 3 ejects ink droplets downward toward the print medium 2 placed on the platen 8. The head 3 of this embodiment ejects ultraviolet curable ink (UV ink). The carriage drive mechanism 5 includes, for example, two pulleys, a belt that is bridged over the two pulleys and a part of which is fixed to the carriage 4, and a motor that rotates the pulleys.

A plurality of nozzles 3a for ejecting ink droplets are formed on the head 3. The plurality of nozzles 3a are arranged in the sub-scanning direction, and the nozzle row is formed by the plurality of nozzles 3a. In the head 3, for example, a plurality of nozzle rows are arranged in the main scanning direction. Further, a plurality of ink chambers 3b are formed in the head 3. Each of the plurality of nozzles 3a is connected to each of the plurality of ink chambers 3b. Further, the upper end of the nozzle 3a is connected to the ink chamber 3b. The opening at the lower end of the nozzle 3a is an ink ejection port from which ink droplets are ejected. The lower surface of the head 3 is a nozzle surface 3c in which a plurality of nozzles 3a are arranged.

The head 3 includes a plurality of piezoelectric elements (piezo elements) 11 for ejecting ink droplets from the nozzle 3a, and a diaphragm 12 to which the piezoelectric elements 11 are attached. The piezoelectric element 11 is composed of a piezoelectric body and two electrodes sandwiching the piezoelectric body. Each of the plurality of piezoelectric elements 11 is arranged on the wall surface of each of the plurality of ink chambers 3b, and ink droplets are ejected from each of the plurality of nozzles 3a. The piezoelectric element 11 of the present embodiment is an ejection energy generating element for ejecting ink droplets from the nozzle 3a.

The plurality of piezoelectric elements 11 are electrically connected to the control unit 6. Print data for printing on the print medium 2 is input to the control unit 6 from a higher-level device (not shown) of the printer 1. The control unit 6 drives the piezoelectric element 11 based on the input print data to eject ink droplets from the nozzle 3a. In the printer 1, the drive frequency of the piezoelectric element 11 is changed without changing the moving speed of the carriage 4, and the ejection timing of the ink droplets ejected from the nozzle 3a is changed, so that the image printed on the print medium 2 is printed. It is possible to change the resolution. For example, in the printer 1, the printing of the printing medium 2 by the first printing mode in which the printing medium 2 is printed at a predetermined resolution and the second printing mode in which the printing medium 2 is printed at a resolution higher than that of the first printing mode. It is possible to print on the print medium 2.

The waveform (voltage waveform) of the voltage applied from the control unit 6 to the piezoelectric element 11 when printing is performed in the first printing mode varies as shown in FIG. 3A, for example. FIG. 3A shows a waveform of the voltage applied to the piezoelectric element 11 when ink droplets are continuously ejected from the nozzle 3a in the shortest cycle in the first printing mode. As shown in FIG. 3A, when ink droplets are continuously ejected from the nozzle 3a from the nozzle 3a in the shortest cycle in the first printing mode, the drive signal SG1 for driving the piezoelectric element 11 is the piezoelectric element 11 at a constant cycle T1. Is entered in.

Further, the waveform (voltage waveform) of the voltage applied from the control unit 6 to the piezoelectric element 11 when printing is performed in the second printing mode fluctuates as shown in FIG. 3B, for example. FIG. 3B shows a waveform of the voltage applied to the piezoelectric element 11 when ink droplets are continuously ejected from the nozzle 3a in the shortest cycle in the second printing mode. As shown in FIG. 3B, when ink droplets are continuously ejected from the nozzle 3a from the nozzle 3a in the shortest cycle in the second printing mode, the drive signal SG2 for driving the piezoelectric element 11 is the piezoelectric element 11 at a constant cycle T2. Is entered in. The period T2 is shorter than the period T1.

As described above, in the first print mode, the ink droplets are continuously ejected from the nozzle 3a in the shortest cycle, and in the second print mode, the ink droplets are continuously ejected from the nozzle 3a in the shortest cycle. In either case, the control unit 6 drives the piezoelectric element 11 at a constant drive frequency. In the following description, the drive frequency of the piezoelectric element 11 when ink droplets are continuously ejected from the nozzle 3a in the shortest cycle during printing on the print medium 2 is defined as the maximum drive frequency. Specifically, the maximum drive frequency in the first print mode is set to the first maximum drive frequency, and the maximum drive frequency in the second print mode is set to the second maximum drive frequency. The second maximum drive frequency is higher than the first maximum drive frequency. Further, for example, the first maximum drive frequency is 8 (kHz), and the second maximum drive frequency is 9.5 (kHz).

When the printer 1 actually prints the print medium 2 in the first print mode, the drive signal SG1 is input to the piezoelectric element 11 at a time interval that is several times the natural number of the period T1, and the nozzle 3a corresponding to the piezoelectric element 11 is , Ink droplets are ejected at time intervals that are several times the natural number of the period T1. That is, at the time of printing in the first printing mode, the control unit 6 drives the piezoelectric element 11 based on the first maximum driving frequency. Similarly, when the printer 1 actually prints the print medium 2 in the second print mode, the drive signal SG2 is input to the piezoelectric element 11 at a time interval that is several times the natural number of the period T2, and corresponds to the piezoelectric element 11. The nozzle 3a ejects ink droplets at time intervals that are several times the natural number of the period T2. That is, at the time of printing in the second print mode, the control unit 6 drives the piezoelectric element 11 based on the second maximum drive frequency.

Assuming that the area where the print medium 2 is printed by the head 3 in the main scanning direction is the printing area PA, the maintenance unit 10 is installed at the maintenance position MP which is out of the printing area PA in the main scanning direction. The carriage 4 can move to the maintenance position MP. That is, the head 3 can move to the maintenance position MP.

The maintenance unit 10 includes a cap member 15 for covering the nozzle surface 3c of the head 3 from below. The cap member 15 has a cap position where the cap member 15 covers the nozzle surface 3c from below (the position indicated by the alternate long and short dash line in FIG. 1) and a retracted position where the cap member 15 retracts so as to be separated from the nozzle surface 3c (FIG. 1). It is possible to move to and from the position indicated by the solid line of. The cap member 15 arranged at the cap position is in close contact with the edge of the nozzle surface 3c.

The cap member 15 moves between the cap position and the retracted position as the carriage 4 moves in the main scanning direction, for example. Alternatively, the maintenance unit 10 includes a moving mechanism for moving the cap member 15 between the cap position and the retracted position. A suction mechanism (not shown) for sucking ink from the nozzle 3a by the cap member 15 that covers the nozzle surface 3c is connected to the cap member 15. Further, the maintenance unit 10 is provided with, for example, a wiping mechanism (not shown) for wiping off dirt on the nozzle surface 3c.

(Control method for inkjet printer)
FIG. 4 is a flowchart for explaining an example of the control method of the printer 1 shown in FIG.

The control unit 6 moves the head 3 in the print area PA to the maintenance position MP by the carriage drive mechanism 5 when the printing of the print medium 2 is completed or at a predetermined timing during the printing of the print medium 2. At the same time, the cap member 15 arranged at the retracted position is moved to the cap position, and the nozzle surface 3c is covered from below by the cap member 15 (step S1).

After that, the control unit 6 performs a pre-vibration flushing operation in which the head 3 is arranged at the maintenance position MP and drives the piezoelectric element 11 to forcibly eject ink droplets from the nozzle 3a (step S2). That is, the control unit 6 performs a pre-vibration flushing operation before returning the head 3 moved to the maintenance position MP to the print area PA. In step S2, the control unit 6 forcibly ejects ink droplets from all the nozzles 3a, for example.

When the pre-vibration flushing operation is completed, the control unit 6 moves the cap member 15 arranged at the cap position to the retracted position at a predetermined timing before returning the head 3 moved to the maintenance position MP to the print area PA. (Step S3). Further, assuming that the operation of driving the piezoelectric element 11 to vibrate (slightly vibrate) the meniscus M (slight vibration) of the ink in the nozzle 3a without ejecting ink droplets from the nozzle 3a is the meniscus vibration operation, step S3. After that, the control unit 6 performs a meniscus vibration operation (step S4). In step S4, the control unit 6 performs a meniscus vibration operation in all the nozzles 3a, for example.

The control unit 6 drives the piezoelectric element 11 at the maximum drive frequency when the meniscus vibration operation is performed in step S4. Specifically, when the control unit 6 performs the meniscus vibration operation in step S4 and then prints in the first print mode by the head 3 returning to the print area PA, the control unit 6 uses the first maximum drive frequency. When printing is performed in the second print mode by the head 3 that drives the piezoelectric element 11 and then returns to the print area PA, the piezoelectric element 11 is driven at the second maximum drive frequency.

That is, the control unit 6 drives the piezoelectric element 11 at the first maximum drive frequency in the meniscus vibration operation immediately before printing in the first print mode is performed in the print area PA, and printing in the second print mode is performed in the print area PA. In the meniscus vibration operation immediately before performed in, the piezoelectric element 11 is driven at the second maximum drive frequency. In step S4, the time during which the meniscus vibration operation is executed is, for example, 500 (msec).

Further, in step S4, when the piezoelectric element 11 is driven at the first maximum drive frequency to perform the meniscus vibration operation, the control unit 6 inputs from the drive signal SG1 so as not to eject ink droplets from the nozzle 3a. A drive signal with a short time is input to the piezoelectric element 11. Similarly, in step S4, when the piezoelectric element 11 is driven at the second maximum drive frequency to perform the meniscus vibration operation, the control unit 6 is more than the drive signal SG2 so as not to eject ink droplets from the nozzle 3a. A drive signal having a short input time is input to the piezoelectric element 11.

After that, the control unit 6 performs a post-vibration flushing operation of driving the piezoelectric element 11 to forcibly eject ink droplets from the nozzle 3a before moving the head 3 to the print area PA by the carriage drive mechanism 5 (step). S5). In step S5, the control unit 6 forcibly ejects ink droplets from all the nozzles 3a, for example. Further, in step S5, the cap member 15 is arranged at the retracted position. After that, the control unit 6 moves the head 3 to the print area PA by the carriage drive mechanism 5 to print the print medium 2 (step S6).

In this embodiment, the meniscus vibration operation is performed only before the head 3 which has been moved to the maintenance position MP is moved to the print area PA. That is, the meniscus vibration operation is not performed in the nozzle 3a in which the ejection of ink droplets is stopped at a predetermined timing when printing is performed in the print area PA. When the power of the printer 1 is off, the head 3 is arranged at the maintenance position MP, and the nozzle surface 3c is covered from below by the cap member 15. When the power of the printer 1 is turned on, for example, steps S2 to S6 are sequentially executed.

(Main effect of this form)
As described above, in the present embodiment, the control unit 6 performs the meniscus vibration operation before moving the head 3 which has moved to the maintenance position MP to the print area PA. Therefore, according to the study of the inventor of the present application, in the present embodiment, the meniscus vibration operation is not performed in the nozzle 3a in which the ejection of ink droplets is stopped at a predetermined timing when printing is performed in the print area PA. It is possible to suppress clogging of the nozzle 3a, which has stopped ejecting ink droplets at a predetermined timing during printing.

Further, in this embodiment, the meniscus vibration operation is performed only before the head 3 which has been moved to the maintenance position MP is moved to the print area PA, and the ink is ink at a predetermined timing when printing is performed in the print area PA. The meniscus vibration operation is not performed in the nozzle 3a in which the ejection of droplets is stopped. Therefore, in this embodiment, it is possible to reduce the frequency with which the piezoelectric element 11 is driven. Therefore, in the present embodiment, the life of the piezoelectric element 11 can be extended, and as a result, the life of the head 3 can be extended. That is, in the present embodiment, it is possible to extend the life of the head 3 even if it is possible to suppress clogging of the nozzle 3a that has stopped ejecting ink droplets at a predetermined timing during printing.

In this embodiment, the control unit 6 performs a post-vibration flushing operation after performing the meniscus vibration operation and before moving the head 3 to the print area PA. Therefore, according to the study of the inventor of the present application, in the present embodiment, the ink is ink at a predetermined timing during printing even if the meniscus vibration operation is not performed in the nozzle 3a in which the ejection of ink droplets is stopped at a predetermined timing during printing. It is possible to effectively suppress clogging of the nozzle 3a in which the ejection of droplets is suspended.

In this embodiment, the control unit 6 drives the piezoelectric element 11 at the first maximum drive frequency in the meniscus vibration operation immediately before printing in the first print mode is performed in the print area PA, and printing in the second print mode is printed. The piezoelectric element 11 is driven at the second maximum drive frequency in the meniscus vibration operation immediately before being performed in the region PA. Therefore, in this embodiment, it becomes easy to control the printer 1 when performing the meniscus vibration operation.

(Other embodiments)
The above-described embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be carried out without changing the gist of the present invention.

In the above-described embodiment, the control unit 6 keeps the cap member 15 in the retracted position even after the head 3 is moved to the maintenance position MP, and the head 3 moved to the maintenance position MP is placed in the print area PA. Before returning, the meniscus vibration operation may be performed without performing the pre-vibration flushing operation. Further, in the above-described embodiment, the control unit 6 may move the cap member 15 arranged at the cap position to the retracted position before performing the pre-vibration flushing operation. Further, in the above-described embodiment, the control unit 6 does not have to perform the post-vibration flushing operation after performing the meniscus vibration operation and before moving the head 3 to the print area PA.

In the above-described embodiment, the control unit 6 may drive the piezoelectric element 11 at a drive frequency other than the first maximum drive frequency in the meniscus vibration operation immediately before printing in the first print mode is performed in the print area PA. Further, the control unit 6 may drive the piezoelectric element 11 at a drive frequency other than the second maximum drive frequency in the meniscus vibration operation immediately before printing in the second print mode is performed in the print area PA.

In the above-described embodiment, the printer 1 can print the print medium 2 in the first print mode and print the print medium 2 in the second print mode in which the resolution of the print medium 2 is higher than that in the first print mode. However, for example, in the printer 1, printing of the print medium 2 in the first print mode, printing of the print medium 2 in the second print mode in which the resolution of the print medium 2 is higher than that in the first print mode, and the second print mode. It may be possible to print the print medium 2 in the third print mode in which the resolution of the print medium 2 is higher than that of the print medium 2.

In the above-described form, the head 3 may eject water-based ink. However, when the ink ejected from the head 3 is an ultraviolet curable ink as in the above-described form, the viscosity of the ink is higher than that in the case where the ink ejected from the head 3 is a water-based ink. Is unlikely to rise over time, so even if the nozzle 3a, which pauses ink droplet ejection at a predetermined timing during printing, does not perform the meniscus vibration operation, the eyes of the nozzle 3a, which pauses ink droplet ejection. It becomes easier to suppress clogging.

In the above-described embodiment, the ejection energy generating element for ejecting ink droplets from the nozzle 3a is the piezoelectric element 11, but the ejection energy generating element for ejecting ink droplets from the nozzle 3a is a heater (heating element). There may be. That is, in the above-described form, the printer 1 ejects ink droplets from the nozzle 3a by the piezo method, but the printer 1 may eject the ink droplets from the nozzle 3a by the thermal method. Further, in the above-described form, the printer 1 may be a 3D printer for modeling a three-dimensional modeled object.

1 Printer (Inkjet printer)
3 heads (injection heads)
3a Nozzle 3c Nozzle surface 4 Carriage 5 Carriage drive mechanism 6 Control unit 10 Maintenance unit 11 Piezoelectric element (discharge energy generating element)
15 Cap member M Meniscus MP Maintenance position PA Printing area Y Main scanning direction

Claims (9)

In an inkjet printer that ejects ink droplets for printing
An inkjet head in which a plurality of nozzles for ejecting ink droplets are formed, a carriage on which the inkjet head is mounted, a carriage drive mechanism for reciprocating the carriage in the main scanning direction, and prevention of clogging of the plurality of nozzles. A maintenance unit for performing the operation and a control unit for controlling the inkjet printer are provided.
The inkjet head includes a plurality of ejection energy generating elements for ejecting ink droplets from each of the plurality of nozzles.
Assuming that the area where printing by the inkjet head is performed in the main scanning direction is a printing area, the maintenance unit is installed at a maintenance position outside the printing area in the main scanning direction.
When the operation of driving the ejection energy generating element to vibrate the meniscus of the ink in the nozzle without ejecting ink droplets from the nozzle is called the meniscus vibration operation, the control unit has moved to the maintenance position. An inkjet printer characterized in that the meniscus vibration operation is performed only before the inkjet head is moved to the printing area. After performing the meniscus vibration operation, the control unit drives the ejection energy generating element to forcibly eject ink droplets from the nozzle before moving the inkjet head to the printing area. Post-vibration flushing The inkjet printer according to claim 1, wherein the operation is performed. Before the vibration, the control unit drives the ejection energy generating element to forcibly eject ink droplets from the nozzle before performing the meniscus vibration operation with the inkjet head arranged at the maintenance position. The inkjet printer according to claim 1 or 2, wherein the flushing operation is performed. The maintenance unit includes a cap member for covering the nozzle surface of the inkjet head in which a plurality of the nozzles are arranged from below.
The cap member is movable between a cap position where the cap member covers the nozzle surface from below and a retracted position where the cap member retracts so as to be separated from the nozzle surface.
The control unit moves the inkjet head to the maintenance position, moves the cap member arranged at the retracted position to the cap position, covers the nozzle surface from below with the cap member, and then covers the nozzle surface from below. Before returning the inkjet head moved to the maintenance position to the printing area, the pre-vibration flushing operation is performed, and when the pre-vibration flushing operation is completed, the inkjet head moved to the maintenance position is moved to the printing area. The inkjet printer according to claim 3, wherein the cap member arranged at the cap position is moved to the retracted position at a predetermined timing before returning to the device, and then the meniscus vibration operation is performed. The maintenance unit includes a cap member for covering the nozzle surface of the inkjet head in which a plurality of the nozzles are arranged from below.
The cap member is movable between a cap position where the cap member covers the nozzle surface from below and a retracted position where the cap member retracts so as to be separated from the nozzle surface.
The control unit keeps the cap member in the retracted position even after moving the inkjet head to the maintenance position, and before returning the inkjet head moved to the maintenance position to the printing area. The inkjet according to claim 1 or 2, wherein the meniscus vibration operation is performed without performing the pre-vibration flushing operation of driving the discharge energy generating element to forcibly eject ink droplets from the nozzle. Printer. Assuming that the drive frequency of the ejection energy generating element when ink droplets are continuously ejected from the nozzle at the shortest cycle during printing is the maximum drive frequency,
The inkjet printer according to any one of claims 1 to 5, wherein the control unit drives the discharge energy generating element at the maximum driving frequency when the meniscus vibration operation is performed. In the inkjet printer, printing in the first printing mode in which the ejection energy generating element is driven based on the first maximum driving frequency, which is the predetermined maximum driving frequency, and the maximum having a frequency higher than the first maximum driving frequency. It is possible to print in the second print mode in which the discharge energy generating element is driven based on the second maximum drive frequency which is the drive frequency.
In the meniscus vibration operation immediately before printing in the first print mode is performed in the print area, the control unit drives the discharge energy generating element at the first maximum drive frequency and prints in the second print mode. The inkjet printer according to claim 6, wherein the ejection energy generating element is driven at the second maximum driving frequency in the meniscus vibration operation immediately before the printing is performed in the printing area. The inkjet printer according to any one of claims 1 to 7, wherein the inkjet head ejects ultraviolet curable ink. An inkjet head in which a plurality of nozzles for ejecting ink droplets are formed, a carriage on which the inkjet head is mounted, a carriage drive mechanism for reciprocating the carriage in the main scanning direction, and prevention of clogging of the plurality of nozzles. The inkjet head is provided with a plurality of ejection energy generating elements for ejecting ink droplets from each of the plurality of nozzles, and a region in which printing by the inkjet head is performed in the main scanning direction. Is a print area, the maintenance unit is a control method for an inkjet printer installed at a maintenance position outside the print area in the main scanning direction.
Assuming that the operation of driving the ejection energy generating element to vibrate the meniscus of the ink in the nozzle without ejecting ink droplets from the nozzle is the meniscus vibration operation, the inkjet head that has been moved to the maintenance position is moved to the maintenance position. A control method for an inkjet printer, characterized in that the meniscus vibration operation is performed only before moving to the print area.

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