JP2003320674A - Inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that nozzles clog due to gradual solidification of ink at nozzle openings 19 when a non printing time or a powder supply stop time becomes long in an inkjet recorder. <P>SOLUTION: When a power supply is shut, the interior of a channel of a capping means 20 is cleaned by a cleaning liquid, and then the nozzle openings 19 of a printing head 17 are capped. Even when printing is stopped for a long time or in a power supply stop state for a long term, the cleaning liquid filled in the interior of the channel of the capping means 20 keeps wet the interior of the channel of the capping means 20. Clogging due to solidification of the ink at the nozzle openings 19 can be prevented accordingly. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus that ejects ink droplets from nozzle openings to print a pattern on a recording medium.

[0002]

2. Description of the Related Art An ink jet recording apparatus is provided with an ink jet type print head which receives supply of ink from an ink cartridge, and a paper feeding mechanism which moves a recording medium in a direction perpendicular to a scanning direction of the print head. Recording is performed by ejecting ink droplets onto the recording medium by generating mechanical pressure and thermal energy with respect to the print head while moving in the direction perpendicular to the width direction (main scanning direction) of the recording medium. Be seen. Then, full color printing is possible by ejecting black ink and yellow, magenta, and cyan color inks.

Further, since the ink jet type recording apparatus has an advantage that it can print on a recording medium in a non-contact manner and that printing can be performed without a plate, in recent years, various inks can be selectively used according to the purpose of printing. It has become to.
That is, not only dye inks that can reproduce vivid colors, but also inks in which pigment components are dispersed for the purpose of improving the weather resistance of printed matter, and organic solvents that are not intended to limit the material of printed matter. Various ink types such as the used ink are used.

On the other hand, in these ink jet type print heads, the ink pressurized from the pressure chamber formed inside the print head is ejected from the nozzle openings to eject ink droplets for printing. There is a problem that printing failure occurs due to increase in ink viscosity due to evaporation of the solvent, solidification of ink, adhesion of dust, and inclusion of bubbles in the ink flow path. For this reason, the ink jet recording apparatus is provided with capping means for sealing the nozzle opening surface of the print head during non-printing to prevent drying.

This capping means not only functions as an airtight lid that prevents the ink in the nozzle openings from drying during non-printing, that is, when printing is stopped, but also when the nozzles are clogged, The nozzle opening surface is sealed by the capping means, and the negative pressure from the suction pump connected to the capping means sucks the ink from all the nozzle openings to cause clogging due to the solidification of the ink in the nozzle openings, and to the inside of the ink flow path. It also has the function of eliminating defective ink ejection due to air bubbles.

The forced suction / discharge process of ink for eliminating the clogging of the print head and the state of inclusion of bubbles in the ink flow path is usually called a cleaning operation, and printing is performed after the apparatus has been idle for a long time. When the cleaning switch is restarted, or when the user manually operates the cleaning switch to eliminate the deterioration of the quality of the recorded image, the operation of discharging ink by negative pressure to the print head is executed. It

[0007]

However, in order to cope with various printing, as the print head is filled with various kinds of ink, the ink is gradually discharged from the nozzle opening when the printing is not performed or the power supply is stopped for a long time. There is a problem that it is not possible to recover the clogging of the nozzle due to the solidification. In order to deal with nozzle clogging, a method has been adopted in which the ink in the print head is discharged at the end of the printing operation and replaced with a cleaning liquid medium, but the operation of filling ink again at the start of the printing operation is possible. Since it is necessary, there are problems that wasteful consumption of ink and waste liquid treatment are troublesome.

The present invention has been made in view of the above problems, and an object of the present invention is to suppress the waste of the ink and to avoid the trouble of the replacement of the cleaning liquid and the processing of the cleaning waste liquid. An object of the present invention is to provide an ink jet recording apparatus that can prevent clogging due to thickening of ink only by operating a power switch.

[0009]

That is, in order to solve such a problem, in the present invention, a print head for ejecting ink droplets from a nozzle opening, and an ink supply means for supplying ink to the print head, An ink jet recording apparatus comprising: a capping unit for capping a nozzle opening of the print head; a suction unit connected to the capping unit; and a cleaning medium supply unit for supplying a cleaning liquid medium to the capping unit, the power being cut off. In this case, the nozzle opening surface of the print head is capped after cleaning the inside of the flow path of the capping means with a cleaning medium.

Further, a counter for storing the number of times the ink is sucked by the capping means and the suction means is provided, and the flow rate of the cleaning medium at the time of cleaning the channel of the capping means is adjusted by the value of the counter. .

A first timer for counting the period of time when the capping means is released is provided, and when the channel of the capping means is cleaned by the value of the first timer,
Adjust the flow rate of the cleaning medium.

Further, a second timer is provided for counting a period during which the print execution command and the ink suction command are not inputted, and the cleaning is performed when the flow path of the capping means is cleaned by the value of the second timer. Adjust the medium flow rate.

When the value of the second timer reaches a certain value, the inside of the channel of the capping means is washed with a washing medium,
Then, the power supply is switched to the power saving mode.

When the ink is water-based, the cleaning medium is a liquid mainly composed of a glycol solvent and water.
When the ink is oil-based, the cleaning medium is a liquid mainly containing a glycol-based solvent.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The following examples of the present invention will now be described.

FIG. 1 shows the structure of a printing mechanism of an ink jet recording apparatus according to the present invention. A carriage 11 is connected to a carriage driving motor 12 by a timing belt 14 and guided by a guide shaft 10. It is configured to reciprocate in parallel with the platen 15. A print head 17 that ejects ink and a cleaning head 18 are fixed to the surface of the carriage 11 that faces the platen 15. The cleaning head 18 is supplied with the cleaning liquid from the cleaning liquid cartridge 22. The print head 17 receives ink from the ink cartridge 21 and ejects ink droplets for printing.

The capping means 20 arranged in the non-printing area has a size capable of sealing the surfaces of the nozzle openings 19 of the print head 17 and the cleaning head 18, and is formed in a cup shape from an elastic material such as rubber. There is. At the time of non-printing, the capping means 20 seals the nozzle opening 19 of the print head 17. Also, the capping means 20 is
Pump unit 2 driven by pump driving means 25
3, the print head 17 is brought into close contact with the capping means 20 to forcibly discharge the ink, and the cleaning head 18 is capped during the cleaning operation. When it comes into close contact with the means 20, the cleaning liquid can be forcibly discharged.

In addition, in the vicinity of the capping means 20, after the print head 17 is subjected to the cleaning operation, the nozzle opening 19 is provided in order to recover the nozzle meniscus.
The wiping blade 24 is disposed on the surface of the.

Here, the cleaning liquid cartridge 22 may be installed on the carriage 11, but may be arranged at any position inside and outside the ink jet recording apparatus and supplied to the cleaning head 18 by using a flexible tube (not shown). good.

FIG. 2 shows an embodiment of the control device of the present invention. The operation panel 2 is provided in a partial area of the box 1 that can be easily operated from the outside, and a power switch 3, a paper feed switch 4, a cleaning switch 5, and a display 7 for displaying power supply are installed therein.

The head drive circuit 30 converts the print data from a host (not shown) into bitmap data by the bit data generating means 32 and drives the print head 17 based on the data stored in the print buffer 31. In addition to printing, nozzle opening 1 to eliminate clogging
A signal for ejecting ink droplets is output from 9.

The sealing state determination means 33 is in the capping state when the power of the print head 17 is off, based on the position data of the carriage 11 from the carriage motor control means 34 and the signal from the home position detection means 35. Whether or not it is determined. In the print timer 43, the print head 17 has the capping means 20.
Is to measure the period of time that is released from.

The initial / end processing means 38 detects the operation of the power switch 3, the paper feed switch 4, and the cleaning switch 5 as the initial processing, and performs the paper feeding initial processing and also moves the print head 17 to the capping means 20. Flushing operation for ejecting ink droplets from all the nozzle openings 19 regardless of print data, cleaning operation for adhering the capping means 20 to the print head 17 and sucking ink by the pump unit 23, and then wiping operation by the wiping blade 24. Is to do. Further, as a termination process, when the power switch 3 gives an instruction to turn off, the cleaning head 18 is brought into close contact with the capping means 20, and the pump unit 23 sucks the cleaning liquid from the cleaning head 18, and the capping means 20.
After cleaning the inside of the flow path with the cleaning liquid, the print head 17 is sealed with the capping means 20 and then the power supply to the entire apparatus is terminated.

The power-saving timer 36 starts counting from the time when the power-off means 37 detects that the power is turned on and the processing by the initial / end processing means 38 is finished, and the power is turned off to start the initial / end processing. The timing operation is stopped when the processing by the means 38 is completed. Further, the power saving timer 36 turns on the display 7 when the power is being supplied to the device, and when the power saving mode is set, the display 7 is turned on.
Blink.

Next, the operation of the apparatus thus constructed will be described with reference to FIG.
It will be described based on the flowchart shown in FIG.

When the power switch 3 of the operation panel 2 is operated (S1) and the power is turned on, an initialization process is performed (S2). The initialization unit drives the paper feed motor 22 to execute a paper feed initialization process and eject the recording paper remaining in the print area.

Then, the power saving timer 36 is started immediately (S3). The power-saving timer 36 counts the time during which no print data is input or the time during which no processing such as cleaning is input while the power is on, and when the print data or cleaning processing is input. Reset with.

When print data is input here (S
5) The print head 17 separates from the capping means 20 to perform printing. At this time, the print timer 43 is turned on to start measuring the time required for printing, and the power saving timer 36 is also reset and stopped ( S6). Then, after the printing of the print data is completed and the print data is exhausted (S7), the print head 17 comes into close contact with the capping means 20 and stops (S8). At this time, the print timer 43 stops while holding the value measured so far, and the power saving timer 3
6 starts (S3).

When print data is further input, the same follow chart is followed, but the period from the start of printing to the capping is accumulated and measured by the print timer 43.

The print data is not input, and the power saving timer 3
When the timing of 6 advances and exceeds 5 hours (S9), the cleaning liquid sequence operates (S10). At this time, the value of the print timer 43 and the value of the CL counter 42, which will be described later, are read, and the cleaning liquid is sucked from the cleaning head 18 through the capping means 20 with a suction amount corresponding to the values. When this cleaning liquid sequence ends, the power saving timer 36 is reset and stopped, and the power saving state is set (S11). This state continues until print data is input (S12), and when print data is input, initialization processing is performed (S1).
3) Then, printing is started (S6).

If the print data is not input and the power switch 3 is turned off (S4), the cleaning liquid sequence is performed (S14). At this time, the value of the power saving timer 36 and the print timer 43 are set. And the value of the CL counter 42 are read, and the cleaning liquid is sucked from the cleaning head 18 through the capping means 20 with the suction amount corresponding to the values.

When this cleaning liquid sequence ends, the end processing is performed, and at the same time, the power saving timer 36 and the print timer 4 are executed.
3 is reset and stopped, and the power supply is stopped (S1
5).

Now, the cleaning operation when the cleaning switch 5 is pressed will be described with reference to the flow chart shown in FIG. First, the print head 17 is capped by the carriage motor controller 34.
(S21). Next, the pump unit 23 is operated to suck ink from the print head 17 (S2
2) Further, the wiping blade 24 is moved to the wiping blade 24, and the surface of the nozzle opening 19 is wiped by the wiping blade 24 (S23). After that, in order to recover the nozzle meniscus, a flushing operation of ejecting a predetermined number of inks from all the nozzle openings 19 is performed (S24). Then, at the same time when the CL counter 42 increments by one, the print timer 43 and the power saving timer 36
Is reset.

FIG. 5 is a schematic diagram showing the operation of the cleaning liquid sequence shown in FIG. First, the carriage motor control means 34 brings the cleaning head 18 into close contact with the capping means 20 (a). And the pump unit 2
3 is operated to suck the cleaning liquid from the cleaning head 18,
The capping means 20 is filled with the cleaning liquid. At that time, the cleaning liquid is discharged into the waste liquid tank 26 by the pump unit 23 while re-dissolving the ink that has increased in viscosity and adhered in the flow path of the capping means 20. Then, by the carriage motor control means 34, the print head 17 is brought into close contact with the capping means 20 filled with the cleaning liquid.
The cleaning liquid sequence ends (b).

Here, the cleaning liquid filled in the cleaning liquid cartridge 22 is suitable for dissolving the colorant used in the ink, for example, when the ink is an ink containing water as a main component, the cleaning liquid is water. It is desirable to include a surfactant as a main component in a weight ratio of about 1%. This surfactant reduces the surface tension of the cleaning liquid,
Since the cleaning liquid easily enters between the ink solidified in the channel of the capping means 20 and the channel wall, the solidified ink can be easily discharged. Further, in order to prevent the print head 17 from being clogged by the solidification of the ink even if the inkjet recording apparatus is left unused for a long period of time, it is necessary to keep the moisture in the channel of the capping means 20. The cleaning liquid contains a polyhydric alcohol solvent that is hard to evaporate, such as glycerin, in a weight ratio of 0 to
It is desirable to include about 30%.

When the ink is composed of a dispersion liquid in which the pigment particles are dispersed, the cleaning liquid contains this dispersion liquid, so that the cleaning liquid adheres to the channel of the capping means 20 with increased viscosity. It is possible to redisperse the ink. Further, by including a surfactant in a weight ratio of about 1%, the surface tension of the cleaning liquid is reduced, and the cleaning liquid easily enters between the ink solidified in the flow passage of the capping means 20 and the flow passage wall. The solidified ink can be easily redispersed and discharged.

FIG. 6 is a diagram for defining the suction amount of the cleaning liquid in the cleaning liquid sequence. The amount of the cleaning liquid sucked from the cleaning liquid cartridge 22 through the cleaning head 18 depends on the values of the power saving timer 36, the CL counter 42, and the print timer 43, and the suction amount is 0.7 to
It is decided to be 3 ml. This takes a long time to print, and the larger the value of the print timer 43,
Since the amount of ink discharged to the capping means 20 by flushing during printing is large and the capping means 20 is open for a long time, more solidified ink is added, and therefore the cleaning liquid is washed with a larger amount. It is a setting. Further, the larger the value of the CL counter 42 is, the more the solidified ink in the flow path of the capping device 20 is re-dissolved and discharged by the cleaning, so that the amount of the cleaning liquid required for cleaning is smaller. The setting is good. Furthermore, the power saving timer 36
The larger the value of, the longer the nozzle opening 19 of the print head 17 is sealed by the capping means 20, and the ink in the flow path of the capping means 20 gradually solidifies, so that a larger amount of cleaning liquid is used for cleaning. It is a setting.

As a result, the ink ejected in the flow path of the capping means 20 due to the flushing operation during the printing operation thickens and is solidified around the edge of the capping means 20. The amount of the cleaning liquid discharged to the waste liquid tank 26 can be small because the cleaning liquid necessary for dissolving and discharging is appropriately set and unnecessary suction is not required. Also, the capping means 20
The cleaning liquid filled in the flow path of the capping means 20
Since the inside of the channel is moisturized, it is possible to prevent clogging due to the solidification of ink in the nozzle openings 19, and it is possible to perform printing without problems even when the inkjet recording apparatus is in a long-time printing suspension or in a power-off state. is there.

[0039]

As described above, in the present invention,
A print head that ejects ink droplets from a nozzle opening, an ink supply unit that supplies ink to the print head, a capping unit and a suction unit that sucks ink from the print head, and a cleaning medium supply that supplies a cleaning liquid medium to the capping unit. An ink jet recording apparatus including a means, the nozzle opening surface of the print head is capped after cleaning the inside of the passage of the capping means with a cleaning liquid when the power is cut off. Since the inside can be kept moist with the cleaning liquid, it is possible to prevent clogging due to the solidification of the ink in the print head even when stopped for a long time.

[Brief description of drawings]

FIG. 1 is an assembly perspective view showing a printing mechanism of an ink jet recording apparatus of the present invention.

FIG. 2 is a block diagram showing an embodiment of an ink jet recording apparatus of the present invention.

FIG. 3 is a flowchart showing an operation of the same device.

FIG. 4 is a flowchart showing a cleaning operation of the apparatus.

FIG. 5 is a schematic diagram showing an operation of a cleaning liquid sequence of the apparatus.

FIG. 6 is a table showing a suction amount of a cleaning liquid in a cleaning liquid sequence of the apparatus.

[Explanation of symbols]

2 Operation panel 3 power switch 11 carriage 17 print head 18 Cleaning head 19 nozzle opening 20 capping means 21 ink cartridge 22 Cleaning liquid cartridge 23 Pump unit 36 Power Saving Timer 42 CL counter 43 Print timer

Claims (9)

[Claims] 1. A print head for ejecting ink droplets from a nozzle opening, an ink supply means for supplying ink to the print head, a capping means for capping the nozzle opening of the print head, and the capping means. An inkjet recording apparatus comprising a suction means and a cleaning medium supply means for supplying a cleaning medium to the capping means, wherein after the power supply is cut off, the inside of the channel of the capping means is cleaned with the cleaning medium, An inkjet recording apparatus, wherein the nozzle opening surface of the print head is capped. 2. A counter for storing the number of times the ink is sucked by the capping means and the suction means, and the counter of the cleaning medium when cleaning the flow path of the capping means according to the value of the counter. The inkjet recording apparatus according to claim 1, wherein a flow rate is adjusted. 3. A first timer for measuring a period of time during which the capping means is released, and a flow rate of the cleaning medium at the time of cleaning the flow path of the capping means according to the value of the first timer. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus is adjusted. 4. A second timer for counting a period during which a print execution command and an ink suction command are not input, and a method for cleaning the flow path of the capping means with the value of the second timer is provided. The inkjet recording apparatus according to claim 1, wherein the flow rate of the cleaning medium is adjusted. 5. When the value of the second timer reaches a certain value, the inside of the flow path of the capping means is cleaned with a cleaning medium, and then the power supply is switched to the power saving mode. Item 5. The inkjet recording device according to item 4. 6. When the ink is an ink containing water as a main component, the cleaning medium is a liquid containing water as a main component and a polyhydric alcohol solvent added thereto. 1. The inkjet recording device according to 1. 7. The cleaning medium is a liquid containing water as a main component and a surfactant added when the ink is an ink containing water as a main component. Inkjet recording device. 8. The inkjet recording according to claim 1, wherein when the ink is composed of a dispersion liquid in which pigment particles are dispersed, the cleaning medium contains at least the dispersion liquid. apparatus. 9. When the ink is composed of a dispersion liquid in which pigment particles are dispersed, the cleaning medium contains at least the dispersion liquid, and a surfactant is added. The ink jet recording apparatus according to claim 1, which is characterized in that.