JP2021030643A - Ink jet printing device and printing device - Google Patents

Abstract

To perform cleaning operation at a suitable timing without reducing productivity when printing many sheets.SOLUTION: An ink jet recording device comprises: a printing processing part; a cleaning part; and a control part which performs cleaning operation on the basis of printing processing and a reference cleaning cycle. The control part determines the total number of prints in which the number of prints in one printing job or a plurality of printing jobs which are continuously processed is added to the number of prints since the previous cleaning operation, and changes a cycle of each cleaning operation so that an absolute value as a result of dividing a value, which is obtained by subtracting the value of two or more natural numbers of the reference cleaning cycle closest to the total number of prints from the total number of prints, by the two or more natural numbers falls within a preset threshold range, cleaning operations of the number of two or more natural numbers are performed, and a cleaning operation performed at an end time of printing processing of the total number of prints, and the cycle of each cleaning operation becomes equal.SELECTED DRAWING: Figure 2

Description

The present invention relates to an inkjet printing device and a printing device for cleaning a printing portion such as an inkjet head, and more particularly to an inkjet printing device and a printing device for printing a large number of sheets in one printing job.

Conventionally, an inkjet printing apparatus has been proposed in which ink is ejected from an inkjet head to perform printing processing on printing media such as paper and film.

In such an inkjet printing device, ink may stick to the ink ejection port of the nozzle, or dust such as paper dust generated from the paper may adhere to the ink ejection port. If ink sticks to the ink ejection port of the nozzle or paper dust accumulates, ejection defects such as disturbance of the ink ejection direction from the nozzle or non-ejection may occur.

In order to reduce such ejection defects, a series of operations is known in which ink is forcibly ejected from a nozzle of an inkjet head, so-called purging, and then a wipe blade wipes the ink ejection port of the nozzle. .. As a result, dust on the ink ejection port of the nozzle is removed by the wipe blade together with the ink adhering to the ink ejection port of the nozzle.

Generally, the above-mentioned cleaning operation is performed at a fixed cleaning cycle (for example, every 1000 sheets are printed) in order to maintain a good printing state, but other factors such as the productivity of the inkjet printing apparatus are also taken into consideration. , Various controls have been proposed.

For example, in Patent Document 1, the total number of printed pages, which is the sum of the number of first printed pages already printed and the number of second printed pages of a print job to be printed, is within a predetermined number of pages. In this case, the cleaning operation is performed after the printing process of the print job is completed, and when the total number of printed pages exceeds the upper limit of the page number range, the cleaning operation is performed before the printing process of the print job. As a result, a method for avoiding the cleaning operation during the printing process of the print job has been proposed.

Further, in Patent Document 2, ejection failure occurs in the middle of the printing process, such as when the printing process is performed in continuous unmanned operation day and night, or when the printing process is performed on glossy paper having a high unit price in the photo mode having a high resolution. If you don't want it, it is suggested to shorten the cleaning cycle.

JP-A-2015-83346 Japanese Unexamined Patent Publication No. 2001-219566

However, in Patent Document 1, for example, in the case of multi-sheet printing in which the cleaning cycle is reached twice or more during the printing process of one print job, one print job or two continuously processed. No consideration is given to the method of determining the timing of the cleaning operation when the second and subsequent cleaning cycles arrive immediately after the printing process of the print job. In recent years, the demand for multi-sheet printing as described above has been increasing more and more, and an appropriate method for determining the timing of cleaning operation in such a case is desired.

Further, as in Patent Document 2, if the cleaning cycle is simply shortened, the number of cleaning operations increases and the productivity decreases.

In view of the above circumstances, the present invention provides an inkjet printing device and a printing device capable of performing a cleaning operation at an appropriate timing without reducing productivity when printing a large number of sheets as described above. With the goal.

The inkjet printing apparatus of the present invention controls a printing processing unit having an inkjet head that ejects ink to a printing medium, a cleaning unit that performs a cleaning operation of the inkjet head, and a printing processing unit based on an input print job. It is provided with a control unit that performs printing processing and controls the cleaning unit based on a preset reference cleaning cycle to perform a cleaning operation, and the control unit is provided with one input print job or input continuous printing job. The total number of prints obtained by adding the number of prints of a plurality of print jobs processed in the process and the number of prints from the previous cleaning operation is calculated, and if the total number of prints is larger than the standard cleaning cycle, the total number of prints is used for printing. When the absolute value of the result of dividing the value obtained by subtracting the value of 2 or more natural numbers of the reference cleaning cycle closest to the total number of sheets by the above 2 or more natural numbers is within the preset threshold range, The cycle of each cleaning operation is set so that the cleaning operation is performed a natural number of times of 2 or more, the cleaning operation is performed at the end of the printing process of the total number of prints, and the cycle of each cleaning operation is equal. change.

The inkjet printing apparatus of the present invention calculates the total number of prints obtained by adding the total number of prints of one input print job or a plurality of input continuous print jobs and the number of prints from the previous cleaning operation. Ask. Then, when the total number of prints is larger than the reference cleaning cycle, the value obtained by subtracting the value obtained by subtracting the value of 2 or more natural numbers of the reference cleaning cycle closest to the total number of prints from the total number of prints is used as the above 2 or more natural numbers. Divide.

Then, when the absolute value of the division result is within the preset threshold range, the cleaning operation is performed a natural number of 2 or more times, and the cleaning operation is performed at the end of the printing process of the total number of prints. The cycle of each cleaning operation is changed so that the cleaning operation is performed and the cycle of each cleaning operation is equal.

As a result, when printing a large number of sheets with a plurality of cleaning operations, the cleaning operation is performed at the end timing of a series of print jobs, and the cleaning operation is performed in the middle of the print job, such as just before the end of the print job. It is possible to avoid the annoyance and the decrease in productivity. In addition, changes in the cleaning cycle are minimized, and deterioration of print quality is prevented.

The figure which shows the schematic structure of the inkjet printing system using one Embodiment of the inkjet printing apparatus of this invention. The figure which shows the 1st example of the change of a cleaning cycle The figure which shows the 2nd example of the change of a cleaning cycle The figure which shows the 3rd example of the change of a cleaning cycle A flowchart for explaining the arithmetic processing of the control unit when the cleaning cycle is changed.

Hereinafter, an inkjet printing system using an embodiment of the inkjet printing apparatus of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of the inkjet printing system of the present embodiment.

As shown in FIG. 1, the inkjet printing system of the present embodiment includes an inkjet printing device 1 and a print data generation device 2. In the inkjet printing system of the present embodiment, the print job generated by the print data generation device 2 is output to the inkjet printing device 1, and the inkjet printing device 1 prints on the print medium based on the input print job. Apply processing.

The print data generation device 2 is composed of a computer and includes a printer driver 21 of the inkjet printing device 1. The printer driver 21 generates a print job including print conditions such as manuscript data created by a predetermined manuscript creation application and the number of prints, and outputs the print job to the inkjet printing device 1.

As shown in FIG. 1, the inkjet printing apparatus 1 includes a printing processing unit 10, a cleaning unit 11, a transport unit 12, and a control unit 13.

The print processing unit 10 has a line head in which a plurality of inkjet heads 20 for ejecting ink to a print medium are arranged in a direction orthogonal to the transport direction of the print medium. The print processing unit 10 of the present embodiment has four line heads, and the four line heads are arranged at predetermined intervals along the transport direction of the print medium. The four line heads eject inks of different colors (eg, black, cyan, magenta and yellow).

The cleaning unit 11 cleans the inkjet head 20 included in each line head of the print processing unit 10. The cleaning unit 11 of the present embodiment has a wipe unit, a waste ink tray, and the like provided for each line head. The wipe unit wipes the nozzle surface of the inkjet head 20 of each line head, and the waste ink tray is used when the waste ink discharged from the inkjet head 20 by purging or the inkjet head 20 is wiped by the wipe unit. It receives the waste ink that has fallen into the water. The nozzle surface is a surface on which the ink ejection ports of the nozzles of each inkjet head 20 are arranged.

The cleaning unit 11 is arranged directly under each line head during the cleaning operation, and is arranged at a retracted position other than the transport path of the print medium during the cleaning operation.

The transport unit 12 has a mechanism for transporting the print medium before the print process to the print process section 10 and discharging the print medium that has been printed by the print process section 10. Specifically, the transport unit 12 temporarily stops the print medium conveyed by the primary paper feed roller that picks up the print medium from the paper feed tray, and then sends the print medium to the print processing unit 10 at a predetermined timing. It is provided with a resist roller to be supplied, a transport belt that sucks and sucks the print medium supplied from the resist roller and transports the printing medium directly under the printing processing unit 10, and a fan mechanism that generates suction air in the suction holes formed in the transport belt. ..

The control unit 13 controls the entire inkjet printing device 1. The control unit 13 includes a CPU (Central Processing Unit), a semiconductor memory such as a ROM (Read Only Memory) and a RAM (Random access memory), a storage such as a hard disk, and a communication I / F.

A print control program is installed in the semiconductor memory or the hard disk of the control unit 13, and each part of the inkjet printing device 1 functions when the print control program is executed by the CPU.

In particular, the control unit 13 of the present embodiment controls the print processing unit 10 based on the input print job to perform printing processing, and the cleaning unit 11 and the printing processing unit 10 are performed based on a preset cleaning cycle. Is controlled to perform the cleaning operation.

In the present embodiment, the cleaning cycle is the number of prints that determines the timing of performing the cleaning operation, and the control unit 13 performs the cleaning operation every time the number of prints in the cleaning cycle is printed. For example, when 1000 sheets are set as the cleaning cycle, the control unit 13 performs a cleaning operation every time the number of printed sheets reaches 1000 sheets.

Further, the control unit 13 of the present embodiment receives an input of a print job having a larger number of prints than the cleaning cycle described above, and at that time, the total number of prints obtained by adding the number of prints of the print job and the number of prints from the previous cleaning operation is added. When the relationship between the number of sheets and the cleaning cycle satisfies a preset condition, the cleaning cycle is changed and the cleaning operation is performed according to the changed cleaning cycle.

Specifically, the control unit 13 adds up the number of prints of one input print job or a plurality of input print jobs to be processed continuously and the number of prints from the previous cleaning operation. Calculate the number of sheets. Then, the control unit 13 obtains a value obtained by subtracting a value obtained by subtracting a value of 2 or more natural numbers of the cleaning cycle closest to the total number of prints from the total number of prints, and divides the subtracted value by the above 2 or more natural numbers. Then, when the absolute value of the division result is within the preset threshold range, the control unit 13 changes the cleaning cycle so that the cleaning operation is performed at the end of the printing process of the total number of printed sheets.

Here, changing the cleaning cycle means, for example, changing the cleaning cycle each time when the cleaning cycle is reached twice or more during the printing process of the total number of prints. For example, the standard cleaning cycle is 1000 sheets, and when this cleaning cycle is changed to 1100 sheets, the cleaning operation is performed every time the number of printed sheets reaches 1100 sheets. Hereinafter, the standard cleaning cycle before the change is referred to as a standard cleaning cycle.

Further, the control unit 13 has a page counter that counts the number of printed sheets, and the page counter increments the count number by 1 each time one sheet is printed, but is reset to zero when the cleaning operation is performed. Become.

The control unit 13 of the present embodiment confirms the page counter at the time when the input of the print job is received, and acquires the number of prints from the previous cleaning operation. Further, the control unit 13 acquires the number of prints of the print job by analyzing the input print job, and calculates the total number of prints by adding the number of prints and the count number of the page counter.

Further, the above-mentioned "preset threshold range" is set to a range in which the cleaning operation is not performed immediately before or immediately after the end of the printing process for the total number of prints, for example. The “preset threshold range” may be set, for example, within the range of −10% to + 10% of the reference cleaning cycle.

Hereinafter, the change of the cleaning cycle by the control unit 13 of the present embodiment will be described with reference to specific examples. FIG. 2 is a diagram showing a first example, and is an example of changing the cleaning cycle when the number of prints from the previous cleaning operation is 0, the number of prints of the print job is 3030, and the reference cleaning cycle is 1000. It is a figure explaining. FIG. 2A is a diagram showing the relationship between the reference cleaning cycle and the total number of prints, and FIG. 2B is a diagram showing the relationship between the changed cleaning cycle and the total number of prints. The white triangles shown in FIGS. 2A and 2B indicate the current time, and the black triangles indicate the timing at which the cleaning operation is performed.

In the case of the example shown in FIG. 2, when the control unit 13 performs the cleaning operation according to the reference cleaning cycle, as shown in FIG. 2A, the cleaning operation is performed three times during the printing process of the print job. It takes time to obtain printed matter, which reduces productivity.

Therefore, the control unit 13 determines that the value obtained by dividing the value Sub obtained by subtracting the value obtained by multiplying the cleaning cycle by 3 (3000 sheets) from the total number of printed sheets (3030 sheets) by 3 is within the preset threshold range. Changes the cleaning cycle so that the cleaning operation is performed at the end of the printing process of the total number of printed sheets.

Specifically, the control unit 13 changes the cleaning cycle from 1000 sheets to 1010 sheets. As a result, the control unit 13 performs the cleaning operation twice during the printing process of the print job, and performs the cleaning operation once at the end of printing the total number of printed sheets. It can be shortened and the decrease in productivity can be avoided.

After changing the cleaning cycle from a predetermined cycle (1000 sheets in this case) (1010 sheets in this case) and printing the total number of prints (3030 sheets in this case), the control unit 13 prints in the subsequent printing. Printing is performed by returning the cleaning cycle to the reference cleaning cycle (1000 sheets in this case). Of course, if the predetermined conditions to which the present invention is applied are satisfied for the subsequent print jobs, the cleaning cycle is changed again. It should be noted that the cleaning cycle is returned to the reference cleaning cycle before the change when the printing of the total number of printed sheets is completed, both in the following examples of FIGS. 3 and 4, and also when the arithmetic processing of FIG. 5 is completed. , The same is true.

If the value obtained by dividing the value Sub obtained by subtracting the value obtained by multiplying the cleaning cycle by 3 from the total number of printed sheets by 3 is outside the preset threshold range, the cleaning cycle is not changed. That is, the control unit 13 performs the cleaning operation according to the reference cleaning cycle.

Next, FIG. 3 is a diagram showing a second example, and describes an example in which the number of prints from the previous cleaning operation is 100, the number of prints of the print job is 2000, and the reference cleaning cycle is 1000. It is a figure to be printed. FIG. 3A is a diagram showing the relationship between the reference cleaning cycle and the total number of prints, and FIG. 3B is a diagram showing the relationship between the changed cleaning cycle and the total number of prints. Further, the white triangles shown in FIGS. 3A and 3B indicate the present time, and the black triangles indicate the timing at which the cleaning operation is performed.

In the example shown in FIG. 3, since the number of printed sheets from the previous cleaning operation is 100, the count number of the page counter at the time indicated by the white triangle is 100. Then, the total number of printed sheets is 2100.

In the case of the example shown in FIG. 3, when the control unit 13 performs the cleaning operation according to the reference cleaning cycle, as shown in FIG. 3A, the cleaning operation is performed twice during the printing process of the print job. It takes time to obtain printed matter, which reduces productivity.

Therefore, in the control unit 13, the value obtained by subtracting the value (2000 sheets) obtained by doubling the cleaning cycle from the total number of printed sheets (2000 sheets + 100 sheets = 2100 sheets) and dividing Sub by 2 is a preset threshold range. If it is, the cleaning cycle is changed so that the cleaning operation is performed at the end of the printing process for the total number of prints.

Specifically, the control unit 13 changes the cleaning cycle from 1000 sheets to 1050 sheets. As a result, the control unit 13 performs one cleaning operation during the printing process of the print job, and performs one cleaning operation at the end of printing the total number of printed sheets. It can be shortened and the decrease in productivity can be avoided.

If the value obtained by dividing the value Sub obtained by subtracting the value obtained by subtracting the cleaning cycle from the total number of printed sheets by 2 by 2 is outside the preset threshold range, immediately before the end of the printing process of the total number of printed sheets. Or, since the cleaning operation is not performed immediately after that, the cleaning cycle is not changed. That is, the control unit 13 performs the cleaning operation according to the reference cleaning cycle.

Next, FIG. 4 is a diagram showing a third example, and is a diagram showing an example when there are two print jobs to be processed continuously. Specifically, it is a figure explaining the example in the case where the number of prints from the previous cleaning operation is 0, the number of prints of two print jobs is 200 and 1700, respectively, and the reference cleaning cycle is 1000. FIG. 4A is a diagram showing the relationship between the reference cleaning cycle and the total number of prints, and FIG. 4B is a diagram showing the relationship between the changed cleaning cycle and the total number of prints. The white triangles shown in FIGS. 4A and 4B indicate the current time, and the black triangles indicate the timing at which the cleaning operation is performed.

When the print jobs to be processed continuously are input, for example, in the case of the example of FIG. 4, when the second print job of 1700 sheets is received, the first print job of 200 sheets is input. This is the case when the printing process of is not started. That is, when the predetermined print job is received and the print job received before that has not started the printing process, the above-mentioned predetermined print job and the print job received before that are continuously performed. It is called a print job to be processed.

In the example shown in FIG. 4, the number of prints from the previous cleaning operation is 0, and the number of prints of the two print jobs is 200 and 1700, respectively, so the total number of prints is 1900.

In the case of the example shown in FIG. 4, when the control unit 13 performs the cleaning operation according to the reference cleaning cycle, as shown in FIG. 4A, one cleaning operation is performed during the printing process of the print job, and two prints are performed. After the job printing process, the second cleaning operation is performed when 100 sheets are printed. That is, after the printing process of the two print jobs, the third cleaning operation is performed immediately after the start of the print process of the third print job to be accepted in the future, and it takes time to acquire the printed matter of the third print job. Will be applied, and productivity will decrease.

Therefore, the control unit 13 determines that the value obtained by dividing the value Sub obtained by subtracting the value obtained by doubling the cleaning cycle (2000 sheets) from the total number of printed sheets (1900 sheets) by 2 is within the preset threshold range. Changes the cleaning cycle so that the cleaning operation is performed at the end of the printing process of the total number of printed sheets.

Specifically, the control unit 13 changes the cleaning cycle from 1000 sheets to 950 sheets. As a result, the control unit 13 performs one cleaning operation during the printing process of the two print jobs, and performs one cleaning operation at the end of printing the total number of prints. Therefore, the third print job It is possible to prevent the cleaning operation from being performed immediately after the start of the printing process of, and if the number of prints of the third print job is less than 1000, the cleaning is performed during the printing process of the third print job. Since no operation is performed, it is possible to avoid a decrease in productivity.

If the value obtained by dividing Sub, which is the value obtained by subtracting the value obtained by doubling the cleaning cycle from the total number of prints, by 2 is outside the preset threshold range, immediately after the start of printing of the third print job. Since the cleaning operation is never started, the cleaning cycle is not changed. That is, the control unit 13 performs the cleaning operation according to the reference cleaning cycle. However, when the control unit 13 receives the third print job, the control unit 13 again determines whether or not the reference cleaning cycle has been changed. Therefore, even when the number of prints of the third print job is 1000 or more, it is possible to avoid a decrease in productivity.

Next, the specific arithmetic processing of the control unit 13 when the cleaning cycle is changed will be described with reference to the flowchart shown in FIG.

First, the control unit 13 receives the print job output from the print data generation device 2 (S10). Then, the control unit 13 acquires the number of prints of the print job by analyzing the received print job. Here, the number of prints of the print job is R.

Next, the control unit 13 acquires the number of prints from the previous cleaning operation by checking the count number of the page counter at the time when the print job is accepted. Then, the control unit 13 adds the number of prints (a) from the previous cleaning operation and the number of prints (R) of the print job to calculate the total number of prints (A) (S12).

Next, the control unit 13 compares the absolute value of the subtracted value obtained by subtracting the reference cleaning cycle (B) from the total number of printed sheets (A) with the preset threshold value (F) (S14). Then, when the absolute value (| AB |) is equal to or less than the threshold value (F) (S14, NO), the control unit 13 prints the total number of prints (A) and then performs a cleaning operation ( S32). That is, in this case, since the first cleaning cycle is reached just before or immediately after the printing process of the total number of printed sheets (A) is completed, the control unit 13 performs arithmetic processing for changing the cleaning cycle, which will be described later. The cleaning operation is performed at the timing when the printing process of the total number of printed sheets (A) is completed.

On the other hand, when the absolute value (| AB |) is larger than the threshold value (F) (S14, YES), the control unit 13 compares the total number of prints (A) with the reference cleaning cycle (B). (S16). Then, the control unit 13 does not change the cleaning cycle when the total number of prints (A) is equal to or less than the reference cleaning cycle (B) (S16, NO). That is, in this case, the cleaning cycle is not reached during the printing process of the total number of prints (A), and a sufficient number of prints remains until the timing of the next cleaning operation. The cleaning operation is performed at the timing when the printing process of the total number of printed sheets (A) is completed and the next reference cleaning cycle is reached.

On the other hand, in S16, when the total number of prints (A) is larger than the reference cleaning cycle (B) (S16, YES), the control unit 13 is performing the printing process of the total number of prints (A). In order to find out how many times the reference cleaning cycle is reached, the total number of prints (A) is divided (A / B) by the reference cleaning cycle (B), the division value is C, and the integer part of the division value is D. (S18). The value of D means the number of times the reference cleaning cycle is reached during the printing process of the total number of prints (A).

Then, the control unit 13 sets the integer part of the result of the following equation (1) to E (S20). The value of E means that the difference between the number of prints per print and the reference cleaning cycle (B) when the total number of prints (A) is divided by the number of Ds is calculated.
{(C / D) -1} x B ... (1)

Then, the control unit 13 compares E, which is the result of the above equation (1), with the threshold value (F) (S22). When E ≦ F, the control unit 13 sets the cleaning cycle T1 other than the last to B + E, and sets the last cleaning cycle T2 to A− {(B + E) × (D-1)}. (S30). In S22, when E ≦ F, the case where E ≦ F is defined as “the subtraction value obtained by subtracting the value obtained by subtracting the value of 2 or more natural numbers of the cleaning cycle closest to the total number of prints from the total number of prints to the natural number of 2 or more” in the present invention. The result of division by (positive value) is within the preset threshold range. "

On the other hand, in S22, when E> F (S22, YES), the control unit 13 sets the result of the following equation (2) to G and the absolute value of G to H (S24). That is, the total number of prints (A) and the number of prints for the reference cleaning cycle (D + 1) are compared, and the difference from the reference cleaning cycle (B) for each print is obtained.
{C / (D + 1) -1} × B ... (2)

Then, the control unit 13 compares H and F (S26), and when H ≦ F (S26, YES), sets the cleaning cycle T1 other than the last to B + G, and sets the last cleaning cycle T2 to A−. {(B + G) × D} (S28). In S26, when H ≦ F, the subtraction value obtained by subtracting the value obtained by subtracting the value of 2 or more natural numbers of the cleaning cycle closest to the total number of prints from the total number of prints is subtracted from the above 2 or more natural numbers. The result of division by (negative value) is within the preset threshold range. "

Further, in S26, when H> F (S26, NO), the control unit 13 ends without changing the cleaning cycle. That is, in this case, since the cleaning operation is not performed immediately after the printing process of the total number of printed sheets (A) is completed, the control unit 13 performs the cleaning operation according to the reference cleaning cycle.

The arithmetic processing of S28 and S30 described above is an example of arithmetic processing for making the cycle of each cleaning operation substantially equal when the cycle of the cleaning operation is changed from the reference cleaning cycle. The change in the cycle is minimized to reduce the print quality.

Next, specific calculated values in the control unit 13 in the case of the first to third examples shown in FIGS. 2 to 4 will be described.

First, in the case of the example shown in FIG. 2, since the number of prints from the previous cleaning operation is zero, a = 0, and since the number of prints (R) of the print job (R) = 3030, A = a + R = 3030.

Then, assuming that the reference cleaning number (B) = 1000 and the threshold (F) = 100, in S14 shown in FIG. 5, | AB | = 3030-1000 = 2030, and | AB |> F. Therefore, the process proceeds to S16. In S16, since A> B, the process proceeds to S18.

In S18, since A / B = 3030/1000, C = 3.03 and D = 3. Then, in S20, {(C / D) -1} × B = {(3.03 / 3) -1} × 1000 = 10, so E = 10.

Then, since the relationship between E and F in S22 is E ≦ F, the process proceeds to S30. Then, in S30, T1 = B + E = 1000 + 10 = 1010 sheets. That is, the cleaning cycle other than the last is changed to 1010 sheets. Further, T2 = A- {(B + E) × (D-1)} = 3030-{(1000 + 10) × (3-1)} = 1010 sheets. That is, the final cleaning cycle is changed to 1010 sheets.

Next, in the case of the example shown in FIG. 3, since the number of prints from the previous cleaning operation is 100, a = 100, and since the print job prints (R) = 2000, A = a + R = 2100. ..

Then, assuming that the reference cleaning number (B) = 1000 and the threshold (F) = 100, in S14 shown in FIG. 5, | AB | = 2100-1000 = 1100, and | AB |> F. Therefore, the process proceeds to S16. In S16, since A> B, the process proceeds to S18.

In S18, since A / B = 2100/1000, C = 2.1 and D = 2. Then, in S20, {(C / D) -1} × B = {(2.1 / 2) -1} × 1000 = 50, so E = 50 sheets.

Then, since the relationship between E and F in S22 is E ≦ F, the process proceeds to S30. Then, in S30, T1 = B + E = 1000 + 50 = 1050 sheets. That is, the cleaning cycle other than the last is changed to 1050 sheets. Further, T2 = A-{(B + E) × (D-1)} = 2100-{(1000 + 50) × (2-1)} = 1050 sheets. That is, the final cleaning cycle is changed to 1050 sheets.

Next, in the case of the example shown in FIG. 4, since the number of prints from the previous cleaning operation is zero, a = 0, and the total number of prints of the two print jobs is R = 1900, so A = a + R = 1900. It becomes.

Then, assuming that the reference cleaning number (B) = 1000 and the threshold (F) = 100, in S14 shown in FIG. 5, | AB | = 1900-1000 = 900, and | AB |> F. Therefore, the process proceeds to S16. In S16, since A> B, the process proceeds to S18.

In S18, since A / B = 1900/1000, C = 1.9 and D = 1. Then, in S20, {(C / D) -1} × B = {(1.9 / 1) -1} × 1000 = 900, so E = 900 sheets.

Then, since the relationship between E and F in S22 is E> F, the process proceeds to S24. Then, in S24, {C / (D + 1) -1} × B = {1.9 / (1 + 1) -1} × 1000 = -50, so G = -50 and H = 50.

Then, since the relationship between H and F in S26 is H ≦ F, the process proceeds to S28. Then, in S28, T1 = B + G = 1000-50 = 950 sheets. That is, the cleaning cycle other than the last is changed to 950 sheets. Further, T2 = A-{(B + G) × D} = 1900-{(1000-50) × 1} = 950 sheets. That is, the final cleaning cycle is changed to 950 sheets.

The method for determining the cycle of each cleaning operation is not limited to the above-mentioned arithmetic processing, and other methods may be adopted.

Specifically, for example, a table is created in advance regarding the relationship between the total number of prints and the cycle of the cleaning operation to be changed, and when the total number of prints is input, the cycle of each cleaning operation is called from the above table, and the table is called. The timing of the cleaning operation may be controlled based on the values in the table.

Further, when the number of prints of a plurality of print jobs processed continuously is about twice or more the standard cleaning cycle, the number of prints of each print job is within a predetermined range from the number of sheets in the standard cleaning cycle. If there is a job, control may be performed to adjust the timing of the cleaning operation so as to be the end time of the print job. Further, as described above, when there are a plurality of print jobs in which the number of print jobs is within a predetermined range from the number of sheets in the reference cleaning cycle, control is performed to adjust the timing of the multiple cleaning operations in the same manner as described above. You may.

The present invention is applicable not only to an inkjet printing device but also to, for example, a laser printing device. In a racer type printing device, when an IH (Induction Heating) type fixing part is used, if the toner is repeatedly fixed, the wax agent contained in the toner is deposited on the fixing part, which affects the fixing performance. .. Therefore, in the case of a laser-type printing apparatus, as a cleaning operation, a process of melting and heating the fixing portion to melt and flow out the wax agent is performed.

Further, the following additional notes will be disclosed with respect to the inkjet printing apparatus and the printing apparatus of the present invention.
(Additional note)

In the inkjet printing apparatus of the present invention, the control unit subtracts a value obtained by subtracting a value of 2 or more natural numbers of the reference cleaning cycle closest to the total number of prints from the total number of prints, and divides the value by the above 2 or more natural numbers. When the absolute value of is within the preset threshold range and the subtracted value is positive, each cleaning cycle can be made longer than the reference cleaning cycle.

Further, in the inkjet printing apparatus of the present invention, the control unit subtracts a value obtained by subtracting a value obtained by subtracting a value of 2 or more natural numbers of the reference cleaning cycle closest to the total number of prints from the total number of prints and dividing by the above 2 or more natural numbers. When the absolute value of the result is within the preset threshold range and the subtracted value is negative, each cleaning cycle can be made shorter than the reference cleaning cycle.

Further, the printing apparatus of the present invention controls the printing unit for printing on the printing medium, the cleaning unit for cleaning the printing unit, and the printing unit based on the input print job, and prints in advance. It is equipped with a control unit that controls the cleaning unit to perform cleaning based on the set reference cleaning cycle, and the control unit determines the number of printed sheets of one or more input print jobs and the number of prints from the previous cleaning. The total number of prints added is calculated, and when the total number of prints is larger than the standard cleaning cycle and multiple cleanings are required, at least once during the execution of the above one or more print jobs. It is controlled to change the cleaning cycle each time so that the cleaning is performed at the end of the one or more print jobs.

1 Inkjet printing device 2 Print data generator 10 Printing processing section 11 Cleaning section 12 Transport section 13 Control section 14 Control section 20 Inkjet head 21 Printer driver

Claims (4)

A print processing unit having an inkjet head that ejects ink to a print medium,
A cleaning unit that cleans the inkjet head,
It is provided with a control unit that controls the print processing unit to perform printing processing based on an input print job and controls the cleaning unit to perform the cleaning operation based on a preset reference cleaning cycle.
The control unit obtains the total number of prints obtained by adding the number of prints of one input print job or a plurality of input print jobs to be processed continuously and the number of prints from the previous cleaning operation, and prints the prints. When the total number of sheets is larger than the reference cleaning cycle, the value obtained by subtracting the value obtained by subtracting 2 or more natural multiples of the reference cleaning cycle closest to the total number of prints from the total number of prints is divided by the 2 or more natural numbers. When the absolute value of the result is within a preset threshold range, the cleaning operation is performed a natural number of times of 2 or more, and the cleaning operation is performed at the end of the printing process for the total number of prints. An inkjet printing apparatus that changes the cycle of each cleaning operation so that the cycle of each cleaning operation is uniform. The absolute value of the result of the control unit subtracting a value obtained by subtracting a value of 2 or more natural numbers of the reference cleaning cycle closest to the total number of prints from the total number of prints by the 2 or more natural numbers is obtained. The inkjet printing apparatus according to claim 1, wherein each cleaning cycle is made longer than the reference cleaning cycle when the value is within the preset threshold range and the subtracted value is positive. The absolute value of the result of the control unit subtracting a value obtained by subtracting a value of 2 or more natural numbers of the reference cleaning cycle closest to the total number of prints from the total number of prints by the 2 or more natural numbers is obtained. The inkjet printing apparatus according to claim 1, wherein each cleaning cycle is made shorter than the reference cleaning cycle when the value is within a preset threshold range and the subtracted value is negative. A printing unit that prints on print media,
A cleaning unit that cleans the printing unit and
A control unit that controls the printing unit to perform printing based on an input print job and controls the cleaning unit to perform the cleaning based on a preset reference cleaning cycle is provided.
When the control unit obtains the total number of prints obtained by adding the number of printed sheets of one or more input print jobs and the number of prints from the previous cleaning, and the total number of prints is larger than the reference cleaning cycle. If the cleaning is required multiple times, each time the cleaning is performed at least once during the execution of the one or more print jobs and at the end of the one or more print jobs. A printing device that controls to change the cleaning cycle of the above.