JP2002264359A - Method for controlling ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a consumption amount of ink in a refreshing operation. SOLUTION: The refreshing operation is carried out only to nozzles which have not reached the number of ink discharge times determined for a fixed term, whereby a use amount of the ink is saved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for controlling an ink jet recording apparatus.

[0002]

2. Description of the Related Art A printing mechanism in a general ink jet recording apparatus includes a head for discharging ink, a carriage on which these heads are mounted, a carriage driving means for moving the carriage in a horizontal direction, and The printing apparatus further includes a paper feeding unit for transporting the printing paper, and a head cap for preventing the ink of the head from drying.

[0003] In such an ink jet recording apparatus, a carriage is moved in a horizontal direction by a carriage driving means, and ink is ejected from a head in synchronization with the amount of movement of the carriage to perform printing on printing paper. Such a system is called a serial system. Then, when the carriage moves by a predetermined width, the printing operation for one scan is completed, and such a printing operation is executed by the required number of scans.

An ink jet controller for controlling such a printing operation receives print data from a host computer, develops the print data into raster data, and holds the raster data in a frame memory. When the development process for one scan is completed, the printing mechanism is controlled to
Perform printing for the scan. When printing for one scan is completed, a paper feeding operation is performed. In the meantime, raster data for scanning is created, and when the creation is completed, the same processing as described above is performed. This scanning operation and paper feeding operation are repeated as many times as necessary, and printing is completed.

In such a serial type ink jet recording apparatus, the number of lines corresponding to the number of nozzles in the vertical direction of the head is printed by one scan. On the head, n nozzles are arranged in a vertical direction, and n lines are printed by printing for one scan. When printing for one scan is completed, a paper feeding operation for transporting the printing paper is executed in preparation for the next scan. Printing proceeds by the scanning operation and the paper feeding operation.

A head of an ink jet recording apparatus has a plurality of nozzles for discharging ink, and has a structure in which ink is discharged by a change in pressure of ink in an ink chamber which communicates with the nozzles to perform printing. ing.

If such a head is not used for a long time, the ink near the nozzles dries and the nozzles may be clogged. In order to prevent nozzle clogging due to such drying, a method of sealing the head with a head cap provided outside the printing range is adopted. However, when the sealing period is long, the viscosity of the ink increases, which causes a printing quality to drop or a printing omission to occur due to an ink ejection failure. In addition, during printing, a period during which a certain nozzle does not eject ink may be long. In such a case as well, the ink near the nozzle dries as in the case described above, causing the nozzle to be clogged, which may result in ink ejection failure even during printing.

As a function for solving such a problem, before starting printing, a predetermined amount of ink is ejected from all nozzles of the head at a position of the head cap outside the printing range, and ink near the nozzles is discharged. It has a function to perform the switching operation. This ink replacement operation is called a refresh operation. In addition, during printing, the carriage on which the head is mounted is moved to the position of the head cap every time a predetermined period elapses, and the refresh operation is performed.

In this refresh operation, when a monitoring timer detects that a certain period has elapsed, the head is moved to a position of a head cap provided outside the printing range to eject ink from all nozzles. It is configured to perform this. When the refresh operation is completed, the monitoring timer is restarted in preparation for the next detection, and control is performed so that the refresh operation is executed every time a certain period of time elapses.

[0010]

According to such a conventional control method, after a certain period of time has elapsed during printing, a refresh operation of discharging ink from all nozzles and discarding ink is performed. Ink is also ejected from a nozzle that does not need a refresh operation because the ejection operation is continued. As a result, there is a problem that the frequency of wasteful consumption of ink increases.

An object of the present invention is to provide a control method for an ink jet recording apparatus which can reduce the amount of ink discarded (consumed) in a refresh operation.

[0012]

SUMMARY OF THE INVENTION The present invention focuses on the fact that it is possible to determine which nozzle is used for ink ejection by referring to print data, By adding a process of counting the number of ejections of each nozzle and controlling so that the refresh operation is performed only for the nozzles that need to be refreshed, wasteful consumption of ink is reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings.

FIG. 3 shows a printing mechanism in the ink jet recording apparatus according to this embodiment. The printing mechanism 11 includes a head 15 for discharging ink.
, A carriage 14 on which these heads 15 to 18 are mounted, and a carriage motor 20 for moving the carriage 14 in a horizontal direction along a guide rail 21.
And a belt 19; a paper feed motor 22 and a tractor 23 for transporting the printing paper 12;
Head cap 13 for preventing ink drying
Is provided. Heads 15 to 18 mounted on carriage 14
Although the number varies depending on the product, this embodiment exemplifies four heads.

In such an ink jet recording apparatus, the carriage 14 is moved in the horizontal direction by the carriage motor 20 and the belt 19, and ink is ejected from the heads 15 to 18 in synchronization with the amount of movement of the carriage 14, so that printing paper is printed. 12 is printed. Such a system is called a serial system. And carriage 1
When 4 moves by a predetermined width, the printing operation for one scan is completed, and such a printing operation is executed by the required number of scans.

In such a serial type ink jet recording apparatus, the number of lines corresponding to the number of nozzles in the vertical direction of the head is printed by one scan. Fig. 4
This will be described below.

In FIG. 4, one head 15 (to 1)
In 8), n nozzles are arranged in the vertical direction, and n lines are printed by printing for one scan. When printing for one scan is completed, the tractor is driven by the paper feed motor in preparation for the next scan, and a paper feed operation for transporting print paper is performed. Printing proceeds by the scanning operation and the paper feeding operation.

An ink jet controller for controlling such a printing operation will be described with reference to FIG.

The host computer 4 has a function of transmitting print data to the ink jet controller 3 by adding a command as necessary.

The ink jet controller 3 receives the print data from the host computer 4 at the reception processing unit 5 and stores the data in the reception buffer 6. In parallel with the data reception by the reception processing unit 5, the expansion processing unit 7 sequentially reads out and analyzes the print data in the reception buffer 6,
The raster data is developed and written into the frame memory 8.
Then, when the development processing for one scan is completed, an instruction for a printing operation for one scan is issued to the printing mechanism control processing 9.

When the printing mechanism control processing section 9 receives an instruction for a printing operation for one scan, it issues a printing start instruction to the printing mechanism control section 10. The printing mechanism control unit 10 reads out raster data from the frame memory 8 in accordance with the operation of the carriage 14, and matches the head 1 with the data.
Printing is performed by discharging ink from 5 to 18 nozzles. When printing for one scan is completed, the printing mechanism control unit 10 drives the paper feed motor 22 to perform a paper feed operation. In the meantime, the rasterization processing unit 7 creates the next raster data for scanning, and when the creation is completed, performs the same processing as described above. This scanning operation and paper feeding operation are repeated as many times as necessary, and printing is completed.

The head 15 of this ink jet recording apparatus
18 have a plurality of nozzles for ejecting ink, and have a structure in which ink is ejected by a change in pressure of ink in an ink chamber communicating with the nozzles to perform printing.

In such a head, as described above, if the ink is not used for a long time, the ink near the nozzle dries, and the nozzle may be clogged. In order to prevent nozzle clogging due to such drying,
As shown in FIG. 3, the head is sealed with a head cap 13 provided outside the printing range. However, when the sealing period is long, the viscosity of the ink increases, which causes a printing quality to drop or a printing omission to occur due to an ink ejection failure. In addition, during printing, a period during which a certain nozzle does not eject ink may be long. In such a case as well, the ink near the nozzle dries as in the case described above, causing the nozzle to be clogged, which may result in ink ejection failure even during printing.

Therefore, the printing mechanism control processing section 9 controls the carriage 1 on which the heads 15 to 18 are mounted before starting printing and every time a certain period elapses during printing.
4 is moved to the position of the head cap 13 to execute a control process for performing a refresh operation.

The refresh operation control processing executed by the printing mechanism control processing section 9 in this embodiment will be described with reference to FIG. In order to execute this control processing, the printing mechanism control processing unit 9 includes a monitoring timer and a counter corresponding to each nozzle.

When activated, first, a monitoring timer is activated to detect a predetermined period in which the refresh operation is performed in advance (S101). If printing is in progress (S1
02), the counter corresponding to the nozzle used for ink ejection is updated by the nozzle ejection number counting process (S103). When the monitoring timer detects that a certain period has elapsed (S104), the refresh operation process according to this embodiment is executed.

In this refresh operation process, it is determined whether or not a refresh operation is necessary based on the value counted in the nozzle ejection number counting process (S103) (S1).
05) If a refresh operation is required, the head is moved to a position (cap position) of the head cap 13 provided outside the printing range, and a refresh operation for discharging ink only to the nozzles requiring the refresh operation is performed. (S106). After that, the nozzle discharge counter is reset (S107), the monitoring timer is restarted (S108), and a check as to whether or not a certain period of time has elapsed is repeated as described above.

In the conventional refresh operation processing,
Assuming that the number of nozzles is M, the number of ejections during refresh is X, and the amount of one ejection is L, the amount of ink ejected by the refresh operation is the product of M, X, and L (M × X × L). However, in this embodiment, assuming that the number of nozzles requiring a refresh operation is m (M ≧ m), the ink ejection amount in the refresh operation is the product of m, X, and L (m × m).
X × L), which is (M) compared to the conventional refresh operation.
−m) × XL × L, the ink consumption can be saved.

At the time when a certain time has elapsed (S10
If it is determined in 5) that it is not necessary to refresh all the nozzles, it is not necessary to execute the refresh operation. In this case, the amount of ink of M × X × L can be saved, and printing can be performed. Since the frequency of the middle refresh operation is reduced, the throughput can be improved. In particular, in a high-speed ink jet recording apparatus, since the number of nozzles M is as large as several hundreds or more, the effect of saving the ink amount is remarkable.

Although the serial type ink jet recording apparatus has been described above, the present invention can be similarly applied to a line type ink jet recording apparatus. In other words, the serial method is a method in which the carriage is moved while the print object is stationary and the ink is ejected from the head to perform printing, while the line method is a head having a length corresponding to the width of the print object. The printing is performed by moving the printing substrate without moving the head, and discharging ink from the head in synchronization with the amount of movement. Also in the case of the line type, since the head structure is the same, a refresh operation is necessary. Even in this case, the operation can be performed in the same manner as in the case of the serial type.

Although the ink ejection amount of the refresh operation described in the above embodiment is a fixed amount, the ink ejection amount of each nozzle (the number of times of nozzle use) can be determined by the count process 103. Counting the ink discharge amount of the refresh operation in the counting process 10
By performing control in accordance with the value counted in step 3 (a nozzle that uses a large number of times reduces the refresh ink discharge amount), wasteful consumption of ink can be further suppressed.

Such a refresh operation control processing function can be configured to be performed by the printing mechanism control unit 10.

[0033]

According to the present invention, a nozzle which does not reach the predetermined number of times of use during a certain period is detected, and the nozzle is refreshed with a small amount of ink consumption by controlling the nozzle to perform a refresh operation. can do.

[Brief description of the drawings]

FIG. 1 is a block diagram of an inkjet controller in an inkjet recording apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart of a refresh operation control process executed by the inkjet controller shown in FIG. 1;

FIG. 3 is a plan view of a printing mechanism in an embodiment of the inkjet recording apparatus of the present invention.

FIG. 4 is a plan view showing a serial nozzle configuration and a relationship between nozzle numbers and printing lines.

[Explanation of symbols]

Reference numeral 3 denotes an inkjet controller, 9 denotes a printing mechanism control processing unit, and 10 denotes a printing mechanism control unit.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Eiichi Toyama 1060 Takeda, Hitachinaka-shi, Ibaraki F-term in Hitachi Koki Co., Ltd. (reference) 2C056 EA14 EA25 EB08 EB29 EB38 EB49 EC08 EC24 EC54

Claims (4)

[Claims] A print head having a plurality of nozzles for ejecting ink, a mechanism for moving a printing medium, and receiving print data from a host computer;
A development processing unit that develops the print data and converts it into raster data, a control unit that ejects ink based on the raster data and prints in synchronization with the movement of the print head, and a printing operation. Separately, in a control method of an ink jet recording apparatus having a refresh operation means for discharging ink from the nozzle, the refresh operation means controls a refresh operation to discharge ink only to an arbitrary nozzle or an unused nozzle. A method for controlling an ink jet recording apparatus. 2. A print head having a plurality of nozzles for ejecting ink, a mechanism for moving a printing medium, and receiving print data from a host computer,
A developing unit that expands the print data and converts the data into raster data; a control unit that ejects ink based on the raster data in synchronization with the movement of the printing medium; A control method for an ink jet recording apparatus having a refresh operation means for discharging ink, wherein the refresh operation means controls a refresh operation to discharge ink only to an arbitrary nozzle or a nozzle not used. Of controlling an ink jet recording apparatus. 3. The apparatus according to claim 1, further comprising means for detecting an amount of ink ejected during a certain period during printing, wherein the refresh operation is performed only for nozzles having the amount of ink smaller than a certain value. A method for controlling an ink jet recording apparatus, comprising: controlling. 4. A control method for an ink jet recording apparatus according to claim 3, wherein control is performed such that the discharge amount of the ink in the refresh operation is determined according to the discharge amount of the ink during a certain period during printing. .