JPH08267783A - Ink jet printer - Google Patents

Abstract

PURPOSE: To provide an ink jet printer which can prevent the lowering of throughput in the printing of a plurality of pages, reduce the amount of use of ink and also prevent the lowering of throughput by extending the interval of carrying out the empty suction. CONSTITUTION: In an ink jet printer carrying out the empty jetting a cap 5 facing a printing head 1 in a maintenance means 7 for the purpose of preventing the drying of the ink of a nozzle not jetting at the time of printing, an empty jetting control means 12 for carrying out the empty suction every printing time of given page and an empty suction control means 15 for carrying the empty suction for removing empty jetting ink once every several times of empty jetting are provided to prevent the lowering of throughput in the printing of a plurality of pages. Also the empty suction control means 13 is controlled based on a data from a non-jetting nozzle sensing means 15 to reduce the amount of use of ink.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer, and more particularly to an apparatus for maintaining a nozzle head of an ink jet printer.

[0002]

2. Description of the Related Art Ink jet printers are known in which a plurality of nozzles are formed in a head, and ink is ejected through the nozzles as droplets or particles onto a recording medium such as paper to perform recording. In such an inkjet printer, ink is not always ejected from all nozzles in the printing process. For example, in a head having 64 nozzles, the third nozzle to the 48th nozzle are mainly used, and the first nozzle, the second nozzle, and the 49th nozzle to the 60th nozzle are used less frequently. Further, also in the third to 48th nozzles, the frequency of the nozzles to be used differs depending on the character to be printed, and nozzles that are rarely ejected may appear.

When the ejection is not performed in this way, the nozzle may dry and the ejection operation of the ink may be defective when a print signal is supplied. Therefore, conventionally, in order to prevent such a defective ejection operation due to drying of the nozzle, there is a case where an idle ejection operation is performed to eject ink into a cap provided at a position unrelated to printing.

Further, since the ink discharged into the cap due to this idle discharge is gradually accumulated, it is necessary to remove the accumulated ink. Therefore, an operation called empty suction is performed to take out the accumulated ink outside the cap.

In the conventional ink jet printer, all the nozzles are ejected during idle ejection, and when a plurality of printing processes are performed, idle ejection and idle suction are performed for each page.

[0006]

In the conventional ink jet printer, when performing printing processing on a plurality of sheets, idle ejection and idle suction are performed for each page, which indicates the degree of efficiency of printing processing. It has a problem that the throughput is lowered. In particular, the time required for idle discharge is msec
Although it is an order, the time required for empty suction is se
Since it is of the c order, there is a problem that the time required for the printing process becomes long.

Further, in the conventional idle discharge operation, since the discharge is performed for all the nozzles, the rate of increase of the ink accumulated in the cap becomes high, which also causes the idle suction for each page. In addition, since the amount of ink used increases, the life of the ink cartridge also shortens.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned conventional problems and to provide an ink jet printer capable of preventing a decrease in throughput even in a printing process of a plurality of pages. Another object of the present invention is to provide an ink jet printer that can reduce the amount of ink used and can extend the interval of idle suction to prevent a decrease in throughput.

[0009]

SUMMARY OF THE INVENTION The present invention relates to an ink jet printer for performing a blank discharge in a cap facing a print head in a maintenance means in order to prevent ink drying of a nozzle that does not discharge during printing. By providing the idle discharge control means for performing the idle discharge for each print of each of the prints and the idle suction control means for performing the idle suction for removing the discharged ink every multiple times of the idle discharge processing To prevent a decrease in throughput.

Further, according to the present invention, in an ink jet printer for performing idle ejection into a cap facing a print head in a maintenance means in order to prevent ink from drying out of nozzles which do not eject during printing, the nozzles which have not been ejected The amount of ink used is reduced by providing a non-ejection nozzle detection unit for detecting the non-ejection nozzle and an idle ejection control unit for performing the idle ejection only for the nozzles not ejected based on the nozzle data detected by the non-ejection nozzle detection unit. At the same time, the throughput is prevented from decreasing.

Further, according to the present invention, in an ink jet printer for performing idle discharge in a cap facing a print head in a maintenance means in order to prevent ink from drying in nozzles that do not discharge during printing, nozzles that do not discharge Of the number of nozzles that have performed non-ejection nozzle detection means that detects non-ejection nozzles, idle ejection control means that performs idle ejection only for nozzles that have not performed ejection based on the nozzle data detected by the non-ejection nozzle detection means. By providing the idle suction control means for performing the idle suction based on the integrated value, it is possible to reduce the amount of ink used and prevent the throughput from decreasing.

Further, the idle suction control unit can prevent the throughput from decreasing by performing idle suction for each printing of odd pages or performing idle suction for each printing of the first page and a predetermined page.

In the present invention, the idle ejection is an operation of ejecting ink into the cap in the maintenance means, in addition to the printing process based on the print data, in the maintenance means provided other than the printing section. Is an operation of sucking and removing ink accumulated in the cap due to idle ejection in the maintenance means.

[0014]

According to the present invention, when the ink jet printer prints a predetermined number of pages, the blank discharge control means causes the print head to face the cap in the maintenance means for each print of the predetermined page, and the blank discharge is performed in the cap. I do.
This prevents the ink from drying in the nozzles that do not eject during printing. Further, the idle suction control means performs idle suction for each of a plurality of idle discharge processes to remove ink accumulated in the cap due to idle discharge. As a result, the number of idle discharges and idle suctions per page is reduced to prevent a decrease in throughput in the print processing of a plurality of pages.

Further, according to the present invention, the non-ejection nozzle detecting means detects the nozzles that have not ejected during the printing performed by the ink jet printer. Then, the idle discharge control means causes the print head to face the cap in the maintenance means, and based on the nozzle data detected by the non-ejection nozzle detection means, idle discharge only the nozzles that have not been discharged, and discharge during printing. Prevents nozzles from drying out ink. As a result, the amount of ink used can be reduced and throughput can be prevented from lowering as compared with the case of performing idle ejection for all nozzles.

Further, according to the present invention, the non-ejection nozzle detecting means detects the nozzle that has not ejected during the printing performed by the ink jet printer. Then, the idle discharge control means causes the print head to face the cap in the maintenance means, and based on the nozzle data detected by the non-ejection nozzle detection means, idle discharge only the nozzles that have not been discharged, and discharge during printing. Prevents nozzles from drying out ink. Further, the idle suction control means integrates the number of nozzles that have performed idle discharge, and performs idle suction based on the integrated value, so that the idle suction control means performs empty suction based on the amount of ink discharged by the idle discharge and accumulated in the cap. Make a suction. As a result, the amount of ink used is reduced and the number of idle suctions per page is reduced to prevent a decrease in throughput.

Further, the idle suction control means can control the timing of performing the idle processing so as to perform idle suction every time an odd number of pages are printed or every time the first page and a predetermined page are printed. As a result, the number of idle suctions per page is reduced to prevent a decrease in throughput. Further, at least after the printing of the first page, the idle suction is performed, and when the number of printed pages is small, the idle suction processing is surely performed without reducing the throughput.

[0018]

Embodiments of the present invention will now be described in detail with reference to the drawings. (Structure of Embodiment) FIG. 1 is a block diagram for explaining the structure of an embodiment of the present invention. In FIG. 1, a head 1 for printing on a sheet is installed on a carriage 3, and a carriage driving unit 4 moves in a direction indicated by an arrow in the figure to perform scanning on the sheet to perform a printing operation. . The carriage drive means 4 is controlled by the normal carriage drive control means 14. Further, the head 1 is formed with a plurality of nozzles 2 that eject ink to perform printing. The drive control of the nozzle 2 in the normal printing operation is performed by the print control unit 11.

Maintenance means 7 is installed adjacent to the portion where the normal printing operation is performed. The maintenance means 7 is a part that performs operations such as idle discharge and idle suction of the nozzles 2 of the head 1, and is attached to the cap 5 that receives the idle-discharged ink and temporarily stores it, and the print surface of the head. An ink removing unit 6 and the like for removing excess ink when the head 1 moves is provided. The ink removing unit 6 is installed between the cap 5 and the printing unit side.

A blank discharge control means 12 is connected to the nozzle 2, and the nozzle 2 discharges ink into the cap 5 according to a command from the blank discharge control means 12 to perform blank discharge. The blank discharge operation performed by the blank discharge control unit 12 can be set to be performed for each predetermined page.

The cap 5 has an empty suction control means 15
Is connected, and the ink accumulated in the cap 5 is sucked and removed.

Further, a non-ejection nozzle detection means 13 is connected to the print control means 11 and the idle discharge control means 12, and based on a print signal output from the print control means 11, a print ejection is performed during printing. The nozzles that have not been processed are detected, and the detected data is transmitted to the idle discharge control means 12. The blank discharge control means can perform blank discharge control so as to perform blank discharge only for the nozzles that have not been discharged, based on the data for the nozzles that have not been discharged.

Further, the idle discharge control means 12 is provided with a counter for counting the number of times of idle discharge, and sends a command to the idle suction control means every time the number of idle discharge reaches a predetermined number to perform idle suction. Can be done. Further, the idle discharge control means 12 integrates the number of nozzles that have performed idle discharge,
Based on the integrated value, a command can be transmitted to the idle suction control means to perform idle suction.

Note that, for example, fluorosilicone is used as a wiper member for wiping off the ink in the ink removing section 6, and is installed at a position where it comes into contact with the wiper member after wiping in order to absorb the ink wiped off by the wiper member. As the ink absorbing member, for example, a water-resistant continuous porous body such as polyvinyl alcohol can be used.

(Operation of Embodiment) Next, the operation of the embodiment of the present invention will be described.

FIG. 2 is a diagram showing the position of the head in the idle discharge and idle suction operations of the embodiment of the present invention. In a normal printing operation, the head 1 scans a printing portion on which a sheet is placed, as shown in FIG. On the other hand, when performing a maintenance process other than the printing operation, such as idle discharge or idle suction, the head 1 moves to the position of the adjacent evaluation loop maintenance means 7 at the print portion as shown in FIG.

When the head 1 is at the position of the maintenance means 7, the idle discharge control means 12 and the idle suction control means 15 send a control command to the nozzle 2 to perform the idle discharge operation or the idle suction operation.

In the idle discharge operation, ink is discharged from the nozzle 2 into the cap 5. The cap 5 receives the ejected ink and temporarily holds it. on the other hand,
In the idle suction operation, the ink held in the cap 5 is sucked by a pump drive (not shown) and sent to a tank or the like (not shown). By this idle suction, the ink accumulated in the cap 5 is removed.

An ink removing unit 6 is provided between the cap 5 and the printing unit, and when the head 1 moves from the printing unit to the maintenance unit 7, the head 1 moves to the maintenance unit 7 printing unit. At this time, the surface of the head 1 comes into contact with the ink removing portion 6 to remove the unnecessary ink adhering to the head surface.

In the present invention, the idle discharge can be performed every time a predetermined page is printed, and the idle suction can be performed every time the idle discharge is performed a plurality of times. Then, the idle suction performed for each of the plurality of idle discharges can be performed by the idle suction operation for each printing of the odd pages or the idle suction operation for each printing of the first page and the predetermined page.

In addition, empty suction which is performed every plural times of empty discharge is
It can also be performed by a non-ejection nozzle detection unit that detects a nozzle that has not performed ejection, and an idle ejection control unit that performs idle ejection only on the nozzle that has not performed ejection based on the nozzle data detected by the non-ejection nozzle detection unit, Also, a non-ejection nozzle detection unit that detects a nozzle that has not ejected, an idle ejection control unit that performs idle ejection only on a nozzle that has not ejected based on the nozzle data detected by the non-ejection nozzle detection unit, and an idle ejection It is also possible to perform the idle suction control means for performing the idle suction based on the integrated value of the number of nozzles that has performed.

First, an example of the operation of performing the idle suction for each of a plurality of idle discharges by performing the idle suction operation for each print of an odd number page or the idle suction operation for each print of the first page and a predetermined page, This will be described with reference to FIG.

FIG. 3A shows the case where the number of printed pages is one. In this case, after the printing process of the first page is performed, the blank discharge is performed, and then the blank suction is performed to remove the discharged ink, and the process is finished. Generally, in a usage mode in which the number of printed sheets is small, the number of printed pages is often one, and the idle discharge and idle suction operations shown in FIG. 3A are performed. In such a case, since the idle suction is performed after the printing process, the delay in the processing operation time due to the idle suction can be substantially ignored, and the throughput does not decrease.

FIG. 3B shows a case where the number of printed pages is two. In this case, after the printing process of the first page is performed, the blank ejection is performed, then the idle suction is performed to remove the ejected ink, and the printing process of the second page is performed and the process ends. . In this case, as in the case of FIG. 3A, the ink that has been ejected in idle is removed by idle suction.

FIG. 3C shows the case where the number of printed pages is K pages. It should be noted that here, K pages is a predetermined number of pages for which blank ejection is performed. In this case, as in the case of FIG. 3A, after the print processing of the first page and the idle discharge and the idle suction are performed, the print processing of the second page to the Kth page is performed. Then, after the printing of a predetermined number of pages (K pages) is completed, the next blank ejection is performed to prevent the nozzles that have not been ejected during the printing from being dried.

FIG. 3D shows the case where the number of printed pages is αK pages. Note that, here, K page is a predetermined number of pages for which blank discharge is performed, α is an integer, and α is an integer.
It is an example of an operation in which idle suction is performed for each idle discharge. In this case, as in the case of FIG. 3C, the print processing of the first page, the blank discharge and the blank suction are performed, and the blank discharge is performed after the print processing of the second page to the Kth page is performed. (A in the figure). Next, after performing the printing process for the predetermined number of pages K from the (K + 1) th page to the 2Kth page, the blank ejection is performed. Sequentially, after a predetermined number of pages K of printing from the (2K + 1) th page to the 3Kth page, the blank ejection is performed. After repeating the print processing of the predetermined number of pages and the blank discharge (B in FIG. 3), after performing the print processing of the predetermined number of pages K from the {(α-1) K + 1} page to the αK page. A blank suction is performed, and then a blank discharge is performed. As a result, idle suction is performed after each of a plurality of idle discharges.

FIG. 4 is a flow chart for explaining the operation of FIG. 3D, and FIG. 5 is a time chart for explaining the idle discharge operation and the timing of the idle discharge operation in the same operation. Further, FIG. 6 is a diagram for explaining the idle discharge operation and the number of times of the idle discharge operation in the same operation.

In the flowchart of FIG. 4, first, the operation in the printing process of the first page is performed in steps S1 to S7. Here, a counter P for counting the number of pages and a counter N for counting the number of blank discharges are prepared, and their initial values are set to P = 1 and N = 0 (step S1).

When a printing operation is performed in the ink jet printer, the head is moved to the printing position (step S
2), the print processing of the first page is performed based on the print data in FIG. By this printing process, the number of processed pages in FIG. 5 becomes 1 (step S3).

After the printing process of the first page, the head is moved to the position of the maintenance means (step S
4), the ink is ejected from the nozzle into the cap to perform the idle ejection operation. The command signal for performing this idle discharge is indicated by a-1 in FIGS. 5 and 6. In addition, this idle discharge operation causes the idle discharge counter N in FIGS.
Becomes 1 (step S5).

After that, an idle suction operation for removing the ink accumulated in the cap is performed. This empty suction is shown in FIGS.
In step S-1 (step S
6).

Next, it is determined whether the number of pages to be printed is equal to or greater than the second page. This determination can be made based on, for example, the data of the number of pages included in the print data. Then, when the number of pages to be printed is only one, the process is terminated, and when there is a second page or later, the process proceeds to step S8 and subsequent steps (step S8).
7).

If there is a second page or later, one page is printed in step S8, and 1 is added to P to count the number of processed pages (step S9).
Then, it is determined whether or not the value of the counter P, which has been incremented, reaches a predetermined number of pages K. When the number of printed pages does not reach the predetermined number K, the counter P
Since the value of does not become K, after determining in step S16 whether or not it is the final page, the processes of steps S7 to S9 are repeated until the number of pages for which printing is completed reaches a predetermined number K. During this period, as shown in FIGS. 5 and 6, the number of idle ejections and idle suctions does not increase, but only the number of finished pages increases. During this period, step S1
When the final page is reached in step 6, the process ends at that point (step S10).

In step S10, when the value of the counter P reaches the predetermined number of pages K, the head is moved to the position of the maintenance means (step S11), and the blank ejection is performed (step S12). Add 1 to the counter N. In FIGS. 5 and 6, this idle discharge is a-2.
, The idle discharge counter N is 2. Therefore,
The blank discharge is performed every K number of print pages, and the number of the blank discharge counter N is increased (step S13).

In step S14, it is determined whether or not the number of the increasing idle discharge counters N has become αβ + 1. Here, β is an integer, and the determination in step S14 means that the idle suction process of step S15 is performed every time the idle discharge is performed α times. Therefore, while repeating the processes up to step S13, the blank discharge is performed every K times of the printing process, and the blank suction is performed every α times of this blank discharge.

In addition, empty suction which is performed every plural times of empty discharge is
In the case of performing the non-ejection nozzle detection unit that detects the nozzles that have not performed ejection, and the idle ejection control unit that performs idle ejection only for the nozzles that have not performed ejection based on the nozzle data detected by the non-ejection nozzle detection unit, In the flow chart of FIG. 4 described above, it can be carried out by performing the following processing in the step of blank discharge of step S13.

The non-ejection nozzle detection means 13 receives a signal from the print control means 11 during the printing process and detects the nozzles which have not ejected ink during the printing process. Then, in the process of step S12, the idle ejection control unit 12 receives the data of the nozzles that have not ejected from the non-ejection nozzle detection unit 13 and performs the idle ejection process only for the nozzles that have not ejected.

FIG. 7 is a flowchart of this idle discharge process. Here, the number C representing the nozzles is set, and for the nozzles that have ejected ink in the printing process, a C flag corresponding to the nozzle number is set. Here, it is assumed that the case where the flag is set corresponds to 1 and the case where the flag is not set corresponds to 0.

Then, the value of 1 corresponding to the first nozzle is set to C (step S21), and the flag value FC of the nozzle C (in this case, nozzle 1) is read (step S2).
2). Then, it is determined whether or not the value FC of the read flag is 1 (step S23).

If the flag is not set, idle ejection is performed for that nozzle (step S24), and steps S22 to S24 are repeated for the next nozzle in steps S25 and S26. If the flag is set in step S23, the nozzle does not perform the idle discharge and the process proceeds to step S25.

As a result, the nozzles for which the idle discharge is performed are only the nozzles for which the ink has not been ejected until the idle discharge processing, and the ink is ejected by the printing and there is no need for the idle ejection. With respect to the nozzle, idle discharge can be omitted. Therefore, the amount of ink consumed by the idle ejection can be reduced and the idle suction interval can be widened.

Also, non-ejection nozzle detection means for detecting the nozzles that have not ejected, and idle ejection control means for performing idle ejection only for the nozzles that have not ejected based on the nozzle data detected by the non-ejection nozzle detection means. When the idle suction control means for performing the idle suction based on the integrated value of the number of the nozzles that have performed the idle discharge is performed, the number of the nozzles that performed the idle discharge is determined in the determination of step S14 in the flowchart of FIG. It can be carried out by comparing the integrated value of 1 with the set value. For example, a means for accumulating the number of nozzles that have performed an idle discharge is provided in the idle discharge control means 12, and when the value integrated by the integrating means becomes equal to or more than a set value, the idle suction in step S15 is performed. To do. It should be noted that this set value can be a previously calculated integrated value of the discharge nozzles that require idle suction.

(Effects of Embodiment) When a continuous porous body having water resistance such as polyvinyl alcohol is used as the ink absorbing member for absorbing the ink wiped by the wiper member, the pores are not independent. The porosity can be increased to about 90%, so that good ink holding power can be obtained. Also, since it has excellent chemical resistance, it has good compatibility with ink, can absorb ink without applying excessive pressure, and can prevent the ink removing member from falling off due to pressure load.

[0054]

As described above, according to the present invention,
To provide an inkjet printer capable of preventing a decrease in throughput even in a printing process of a plurality of pages, and reducing an ink usage amount and extending an idle suction interval to prevent a decrease in throughput. You can

[Brief description of drawings]

FIG. 1 is a block diagram for explaining a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a diagram showing a position of a head in idle discharge and idle suction operations according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating an operation example of idle discharge and idle suction in the embodiment of the present invention.

FIG. 4 is a flow chart for explaining one operation of the embodiment of the present invention.

FIG. 5 is a time chart illustrating the timing of the blank discharge operation and the blank discharge operation in one operation of the exemplary embodiment of the present invention.

FIG. 6 is a diagram illustrating the number of idle discharge operations and the number of idle discharge operations in one operation of the embodiment of the present invention.

FIG. 7 is a flow chart of an example of idle discharge processing according to the embodiment of the present invention.

[Explanation of symbols]

 1 Head 2 Nozzle 3 Carriage 4 Carriage Drive Means 5 Cap 6 Ink Removal Section 7 Maintenance Means 11 Print Control Means 12 Ejection Control Means 13 Non-Ejection Nozzle Detection Means 14 Carriage Drive Control Means 15 Empty Suction Control Means

Claims (5)

[Claims] 1. An ink jet printer that performs blank discharge in a cap facing a print head in a maintenance means in order to prevent ink drying of a nozzle that does not discharge during printing, and performs blank discharge every time a predetermined page is printed. An ink jet printer comprising idle discharge control means and idle suction control means for performing idle suction for removing idle-discharged ink every plural times of idle discharge. 2. An ink jet printer that performs blank ejection in a cap facing a print head in a maintenance means in order to prevent ink from drying in nozzles that do not eject during printing, does not detect nozzles that have not ejected. An inkjet printer comprising: an ejection nozzle detection unit; and an idle ejection control unit that performs idle ejection only for nozzles that have not performed ejection based on the nozzle data detected by the non-ejection nozzle detection unit. 3. An ink jet printer that performs blank ejection in a cap facing a print head in a maintenance means in order to prevent ink from drying in nozzles that do not eject during printing, does not detect nozzles that have not ejected. A discharge nozzle detection unit, a blank discharge control unit that performs blank discharge only for nozzles that have not discharged based on the nozzle data detected by the non-discharge nozzle detection unit, and an integrated value of the number of nozzles that have performed blank discharge. An ink jet printer comprising an idle suction control means for performing idle suction based on the above. 4. The ink jet printer according to claim 1, wherein the idle suction control means performs idle suction every time an odd number of pages are printed. 5. The inkjet printer according to claim 1, wherein the idle suction control means performs idle suction for each printing of the first page and a predetermined page.