KR20060133451A - Array type inkjet printer and maintenance method thereof - Google Patents

Abstract

An array type ink-jet printer and a maintenance method thereof are provided to prevent waste of ink due to a maintenance operation and lengthen a lifespan of a nozzle. An array type ink-jet printer includes an ejection number calculation part(21), a cap open time calculation part(30), and a controller(10). The ejection number calculation part calculates the number of ink ejections of each nozzle on the basis of an image to be printed. The cap open time calculation part calculates a cap open time in which an ejection port of the nozzle is opened. The controller controls to perform a maintenance operation of the nozzle smaller than the predetermined number of ink ejections of the nozzle, when the cap open time arrives at a predetermined reference time.

Description

Array type inkjet printer and its maintenance method {ARRAY TYPE INKJET PRINTER AND MAINTENANCE METHOD THEREOF}

1 is a perspective view showing a printing operation of an array inkjet printer;

2 is a schematic structural diagram of an array inkjet printer according to the present invention;

3 is a graph showing a reference value (C1) for determining a management request nozzle and a reference value (C2) for performing maintenance operations according to the number of ejections in the array type inkjet printer of the present invention;

4 is a flowchart illustrating a process of performing a maintenance operation using an array inkjet printer according to the present invention.

Explanation of symbols on the main parts of the drawings

 5: printing unit 6: head

 7: cap 9: nozzle heater

10: control unit 15: memory

16: head drive unit 17: cap drive unit

20: maintenance unit 21: discharge count calculation unit

25: management request nozzle judgment unit 30: cap opening time calculation unit

35 wiper drive portion 40 wiper

The present invention relates to an array type inkjet printer and a maintenance method thereof, and more particularly, to an array type inkjet printer and a method for maintaining the same, which can reduce the amount of ink consumed by a nozzle maintenance operation.

In general, an array type inkjet printer includes a head which is elongated in one direction, and a plurality of nozzles are arranged along the length of the head. Each nozzle is provided with an ejection opening for ejecting ink in its end region, and a cap for opening or closing the ejection opening is provided in the region adjacent to each ejection opening. Each cap mounted to each outlet operates simultaneously to open or close each outlet.

Such an array-type inkjet printer counts the number of ejections of each nozzle before power is applied or starts a print job, and performs maintenance when any one nozzle exceeds the preset number of ejections. There are many different types of maintenance work, the most notable of which are spitting and wiping.

Spitting is a maintenance operation for ejecting the cured ink by ejecting ink from each nozzle, and is for preventing the printing operation from being smoothly performed due to the curing of the ink. In general, a cap for opening and closing each nozzle is opened at the same time during the printing operation of the array type inkjet printer, but there are some nozzles for ejecting ink and some nozzles for not ejecting ink according to the printed image. Therefore, in the case of the nozzle which opens the cap but does not discharge ink, if this situation is repeated, the ink exposed to the air through the discharge port tends to cure. Then, when the ink is cured, the ink cannot be discharged during the printing operation in which the ink must be discharged. To prevent this, spitting is performed on all nozzles.

Wiping is a maintenance operation which wipes out the discharge port area of each nozzle using a wiper. When the repetitive printing operation is performed, ink is deposited around the discharge port, and when the amount of ink buried around the ink is increased, the ink is smeared when the ink is ejected, and the discharge port is clogged in the air supply field. To prevent this, perform wiping.

On the other hand, in general, when printing a print image, the print image is often not evenly distributed in all areas of the paper. For example, when printing a print image as shown in Fig. 1, nozzles disposed in the center region of the head are often used, while nozzles of both end regions (circular regions) of the head are rarely used. Here, spitting is necessary for a nozzle that is rarely used, whereas spitting is not necessary for a nozzle that is used frequently. Nevertheless, since spitting is conventionally performed for all nozzles, ink is wasted.

In particular, in the case of an array type inkjet printer, since the number of nozzles is much larger than that of a general shuttle type printer, when all the nozzles are spun during spitting, the amount of ink consumed is much larger, and ink is wasted.

Accordingly, it is necessary to perform maintenance operations such as spitting adaptively according to the number of use of each nozzle in the array type inkjet printer, so that it is necessary to reduce the consumption of ink and to perform efficient maintenance.

It is therefore an object of the present invention to provide an array type inkjet printer and its maintenance method which can reduce the amount of ink consumed by the maintenance work of the nozzle.

The configuration of the present invention for achieving this object is an array type inkjet printer having a head which is formed elongated in one direction and formed with a plurality of nozzles in a longitudinal direction, the ink of each nozzle based on a print image to be printed. A discharge count calculating unit for calculating a discharge count; A cap opening time calculating unit configured to calculate an opening time of a cap for opening and closing the discharge ports of the nozzles; And, when the cap opening time reaches a preset reference time, characterized in that it comprises a control unit for controlling to perform a maintenance operation for the nozzle having a predetermined number of discharge times of each nozzle.

The ejection frequency calculator may extract at least one of the position of each dot for forming the printed image and information on the color of each dot.

The ejection frequency calculator may calculate the ejection frequency of each nozzle corresponding to each dot from information about the position of the dot and the color of each dot.

It is preferable to further include a management request nozzle determining unit for determining a nozzle for which the number of discharges of each of the nozzles is less than or equal to a predetermined reference value for a predetermined time as the management request nozzle.

The maintenance operation may be at least one of spitting spraying ink from the nozzle and wiping wiping the discharge port of the nozzle with a wiper.

When the cap opening time reaches the reference time, the control unit preferably controls to perform the spitting on the management request nozzle.

It is preferable that each nozzle is equipped with a nozzle heater for heating ink, and the control unit operates the nozzle heater to perform the spitting.

Preferably, the control unit resets the cap opening time and the information on the management request nozzle after completion of the spitting.

The control unit controls to perform spitting and wiping on all the nozzles when the number of discharges of the at least one nozzle exceeds a preset reference value; It is preferable to reset the cap opening time and the information on the management request nozzle after the spitting is completed.

The reference time may be set based on the time taken for the ink of the nozzle to cure.

On the other hand, the above object, according to another field of the invention, in the maintenance method of the array-type inkjet printer having a head which is formed long in one direction and formed with a plurality of nozzles in the longitudinal direction, based on the print image to be printed Calculating the ink ejection frequency of each nozzle by Calculating an opening time of a cap for opening and closing the discharge port of each nozzle; And performing maintenance on the nozzles having a predetermined number of ejection times among the nozzles when the cap opening time reaches a preset reference time. Can also be achieved by

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of an array inkjet printer according to the present invention.

As shown, the present array type inkjet printer includes a print unit 5, a maintenance unit 20, a memory 15, and a control unit 10.

The print unit 5 is operated to print a print image, and includes a head 6, a head drive 16, a cap 7, a cap drive 17, and a nozzle heater 9.

The head 6 is formed in a long bar shape along one side direction, and a plurality of nozzles are formed on the surface of the head 6 facing the paper. At the end of each nozzle, a discharge port for discharging ink is formed, and a cap 7 for opening and closing the discharge port is attached to one end of each nozzle.

The head drive unit 16 moves the head 6 horizontally in the longitudinal direction when printing the print data.

The cap drive unit 17 opens or closes the cap 7 under control from the control unit 10, and the cap drive unit 17 opens the cap 7 at the time of printing the print data and at the time of performing maintenance work. Open.

The nozzle heater 9 is provided inside the nozzle adjacent to the discharge port and heats the ink so that the ink is injected through the discharge port. In general, there are various methods of ejecting ink from the nozzle, but the thermal transfer ink ejection technique of ejecting ink by heat using the nozzle heater 9 is most widely used. The nozzle heater 9 is formed of a thin film heater for generating heat, and when heat is applied to the nozzle heater 9, the ink is heated to convert the liquid ink into a gaseous state, and at this time, the volume change of the ink Will occur. Thereby, ink is pushed by the ink bubble, and ink droplet is ejected through an ejection opening.

The maintenance unit 20 includes a discharge number calculating unit 21, a management request nozzle determining unit 25, a cap opening time calculating unit 30, a wiper 40, and a wiper driving unit 35.

The discharge count calculating unit 21 calculates the discharge count for each nozzle with respect to the input print data. To this end, the ejection frequency calculator 21 extracts information on the number of dots and dot positions constituting the print data, and determines whether to eject each nozzle based on the extracted information. At this time, in the case of a color printer, the number of ejections for each nozzle of C, M, and Y is calculated in consideration of the information on the color of the print data.

Then, the discharge count calculating unit 21 calculates the discharge count for each nozzle accumulated during printing of the print data. At this time, when the print data is color, the ejection frequency calculator 21 calculates the ejection frequency for each nozzle in consideration of how many colors are included in one dot.

The management request nozzle determining unit 25 serves to determine a management request nozzle in which the number of ejections is small and the ink may be cured. The management request nozzle determiner 25 judges the management request nozzle according to the discharge frequency of each nozzle calculated from the discharge frequency calculation unit 21, and manages nozzles in which the discharge frequency of each nozzle is equal to or less than a predetermined reference value C1. Judging by the required nozzle. At this time, the management request nozzle determiner 25 determines the management request nozzle by accumulating the discharge number of each nozzle continuously until the cap opening time reaches a preset reference time, as shown in FIG. Finally, when the cap opening time reaches the reference time, the nozzle for which the number of discharges is equal to or less than the reference value C1 is determined as the management request nozzle. The information on the management request nozzle is stored in the memory 15, and the management request nozzle determiner 25 updates the information on the management request nozzle until the spitting operation for the management request nozzle is performed to the memory 15. Store in

The cap opening time calculating unit 30 accumulates and calculates the time during which the cap 7 is opened while printing the print data. There are several ways to calculate the cap opening time. When the cap opening time calculation unit 30 calculates the cap opening time by one page unit, the cap opening time calculation unit 30 may calculate the cap opening time by using the resolution and printing speed of the print data. The cap opening time can also be calculated according to the capacity, resolution and printing speed. In addition, the cap opening time calculation unit 30 may calculate the cap opening time by subtracting the time of the printing start time from the time of the printing end point, or may calculate the cap opening time by counting the printing time using a timer.

The wiper 40 wipes the discharge port area of the nozzle to remove ink debris on the periphery of the discharge port, and is usually disposed outside the nozzle at one end of the head 6. The wiper 40 is formed in a blade shape of a soft material such as rubber or silicon.

The wiper drive unit 35 drives the wiper 40 to move in contact with the nozzle along the longitudinal direction of the head 6 under the control of the control unit 10.

In the memory 15, print data is temporarily stored, the number of ejections for each nozzle calculated by the ejection frequency calculating section 21, information on the management request nozzles determined by the management request nozzle determining unit 25, and the cap opening time. The cap opening time calculated by the calculating unit 30 is stored. The number of ejections for each nozzle stored in the memory 15, the information on the management request nozzle, and the cap opening time are stored until the maintenance operation is performed.

The controller 10 controls the operations of the print unit 5 and the maintenance unit 20 to perform the maintenance of the printer. The control unit 10 controls the general maintenance work to be performed at ordinary times and the performance of the auxiliary maintenance work for the management request nozzle.

The control unit 10, first, when the power is supplied to the printer, second, just before performing a print job, third, as shown in Figure 3, as shown in Figure 3, even if one of each nozzle discharge the preset reference value (C2) If exceeded, control to carry out general maintenance. General maintenance tasks include wiping and spitting. Accordingly, the controller 10 operates the wiper driver 35 and the nozzle heater 9 to perform wiping and spitting.

When the cap opening time measured by the cap opening time calculating unit 30 reaches a predetermined reference time, the control unit 10 performs spitting on the management request nozzle determined by the management request nozzle determining unit 25. Control to perform. That is, the controller 10 operates the nozzle heater 9 of the management request nozzle so that the spitting is performed. On the other hand, the predetermined reference time described above is preferably set based on the time at which the ink in the area adjacent to the discharge port is cured as the cap 7 is opened.

The maintenance process of the array inkjet printer by the above configuration will be described with reference to FIG. 4.

First, when power is applied (S400), the controller 10 operates the wiper driver 35 and the nozzle heater 9 to perform a power on reset maintenance (PORM) that is a general maintenance operation (S405). In this state in which power is applied, when print data is received (S410), the controller 10 controls an image processor (not shown) to generate a print image (S415).

Then, the control unit 10 operates the ejection count calculator 21 to extract the position and color information of each dot forming the printed image (S420). The ejection frequency calculating unit 21 calculates the ejection frequency of each nozzle corresponding to each dot by using the extracted position and color information (S425). When the number of ejections of each nozzle is calculated, the management request nozzle determiner 25 extracts information on the management request nozzles according to the calculated number of ejections (S430).

When the information on the management request nozzle is extracted, the control unit 10 drives the wiper drive unit 35 and the nozzle heater 9 to perform Begin Of Job Maintenance (BOJM), which is a general maintenance operation before printing (S435). ). Then, the control unit 10 opens the cap 7 of each nozzle (S440), and operates the cap opening time calculating unit 30 to start the measurement of the cap opening time (S445).

The controller 10 determines whether the cap opening time exceeds a preset reference time (S450), and when the cap opening time exceeds the preset reference time, operates the nozzle heater 9 of the management request nozzle to switch the The fitting is performed (S455). Here, the management request nozzle is a nozzle having a discharge number of times lower than or equal to the reference value C1 when the cap opening time reaches the reference time, and refers to nozzles from N1 to N30 and N72 to N100 taking FIG. 3 as an example. In FIG. 3, it is assumed that the number of nozzles is 100, and the discharge frequency of each nozzle is shown in a graph. When the spitting of the management request nozzle is completed, the controller 10 resets the cap opening time stored in the memory 15 and starts the cap opening time measurement again (S460). Then proceed to step S465.

When the cap opening time does not exceed the preset reference time, or when the steps S455 and S460 are performed, the controller 10 determines whether the number of ejections of each nozzle exceeds the preset reference value C2 ( S465). As a result of the determination, when any one of the nozzles has a discharge number exceeding the reference value C2, the nozzles N39, N58 to N63 exceed the reference value C2 by taking FIG. 3 as an example. In this case, the controller 10 operates the wiper driver 35 to perform general maintenance work, and operates the nozzle heaters 9 of all the nozzles to perform wiping and spitting (S470). Then, the cap opening time and the ejection frequency are reset, and the measurement of the cap opening time and the ejection frequency is restarted. At this time, the reason for resetting the cap opening time is that since the general maintenance operation is performed for all nozzles, since the management request nozzle is also spitting, the auxiliary maintenance operation is performed.

Then, the controller 10 controls the print unit 5 to perform a print job of the print image. The control unit 10 continuously determines whether printing is finished during the printing operation, in units of pages and files, and when printing is not finished, returns to step S450 and steps S450 to S485 until the end of printing. Repeat. At this time, the steps S450 to S485 may be performed each time one page printing of the print image is finished.

In this way, the present array type inkjet printer measures the time at which the cap 7 is opened, and performs spitting on a management request nozzle having a discharge frequency equal to or less than a reference value during a predetermined cap opening time. As a result, not only the ink of the management request nozzle which is not frequently used can be prevented from being hardened, but also waste of ink generated when spitting is performed on all nozzles in the past can be prevented. In addition, since efficient and proper maintenance work is performed according to the use state of each nozzle, the life of the head 6 and the nozzle can be extended.

As described above, according to the present invention, it is possible to prevent waste of ink due to maintenance work and to extend the life of the head and the nozzle.

Further, in the detailed description of the present invention, specific embodiments have been described, which should be taken as exemplary, and various modifications may be made without departing from the technical spirit of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims below, but also by the equivalents of the claims.

Claims (18)

In the array-type inkjet printer having a head formed long in one direction and formed with a plurality of nozzles in the longitudinal direction, A discharge count calculating unit for calculating the ink ejection count of each nozzle based on the print image to be printed; A cap opening time calculating unit configured to calculate an opening time of a cap for opening and closing the discharge ports of the nozzles; And, And a control unit which controls to perform a maintenance operation on the nozzles having a predetermined number of ejection times among the nozzles when the cap opening time reaches a preset reference time. The method of claim 1, And the ejection frequency calculator extracts at least one of a position of each dot for forming the printed image and information on the color of each dot. The method of claim 2, And the ejection frequency calculator is configured to calculate the ejection frequency of each nozzle corresponding to each dot from information about the position of the dot and the color of each dot. The method of claim 3, wherein And a management request nozzle determiner configured to determine, as a management request nozzle, a nozzle having a discharge number of the nozzles equal to or less than a predetermined reference value for a predetermined time. The method of claim 4, wherein And the maintenance operation is at least one of spitting to eject ink from the nozzle and wiping to wipe the ejection opening of the nozzle with a wiper. The method of claim 5, And the control unit controls to perform spitting on the management request nozzle when the cap opening time reaches a reference time. The method of claim 6, Each nozzle is equipped with a nozzle heater for heating the ink, And the control unit operates the nozzle heater to perform the spitting. The method of claim 7, wherein And the control unit resets the cap opening time and the information on the management request nozzle after completion of the spitting. The method of claim 8, The control unit controls to perform spitting and wiping on all the nozzles when the number of discharges of the at least one nozzle exceeds a preset reference value; And the cap opening time and the information on the management request nozzle are reset after the spitting is completed. The method of claim 1, And the reference time is set based on the time taken for the ink of the nozzle to cure. In the maintenance method of an array-type inkjet printer having a head is formed long in one direction and formed with a plurality of nozzles in the longitudinal direction, Calculating the ink ejection frequency of each nozzle based on the print image to be printed; Calculating an opening time of a cap for opening and closing the discharge port of each nozzle; And, And performing a maintenance operation on the nozzles having a predetermined number of ejection times among the nozzles when the cap opening time reaches a predetermined reference time. The method of claim 11, The calculating of the discharge number of times, And extracting at least one of the position of each dot for forming the printed image and the information on the color of each dot. The method of claim 12, The calculating of the discharge number of times, And calculating the number of ejections of each nozzle corresponding to each dot from information about the position of the dot and the color of each dot. The method of claim 13, Performing the maintenance work, And determining a nozzle having a discharge frequency of each nozzle equal to or less than a predetermined reference value for a predetermined time as a management request nozzle. The method of claim 14, Performing the maintenance work, And a wiping step of ejecting ink from the nozzle, and a wiping step of wiping the discharge port of the nozzle with a wiper. The method of claim 15, The performing of the maintenance operation may include performing spitting on the management request nozzle when the cap opening time reaches a reference time. The method of claim 16, And after the completion of the spitting, resetting the cap opening time and the information on the management request nozzle. The method of claim 17, Performing spitting and wiping for all the nozzles when the number of discharges of the at least one nozzle exceeds a preset reference value; And resetting information about the cap opening time and the management request nozzle after the spitting is completed.

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