JP2805770B2 - Ink jet recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink-jet recording apparatus, and more particularly to an ink-jet recording apparatus which prevents drying in an ink-jet head and cancels a discharge disturbance due to drying.

[Conventional technology]

Capping means provided with an ink absorber therein is found in JP-A-56-60256. When a trouble such as a discharge failure occurs, the suction pump is operated to suck ink from the nozzle to recover from the trouble. At the same time, the ink absorber in the cap is wetted with ink.

[Problems to be solved by the invention]

However, in the above prior art, the ink absorber is not wetted with the ink unless a trouble occurs, so that a reliable moisturizing effect cannot be obtained. Also, even if the suction pump is operated regularly only for moisturizing, a large amount of ink has been consumed, and when a large amount of ink is contained in the cap, when the cap is released, It was dripping and causing dirt.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording apparatus that eliminates the above-mentioned problems with a simple configuration and at the same time, cancels the ejection disturbance due to ink drying of a nozzle portion.

[Means for solving the problem]

An ink jet recording apparatus according to the present invention includes a capping unit that covers a nozzle portion of an ink jet head and has an ink absorber disposed in an internal space, a suction unit that communicates with the internal space of the capping unit, and an internal space of the capping unit. An ink jet recording apparatus provided with a valve that communicates with or shuts off the atmosphere, wherein the capping unit covers the nozzle unit, and the internal space of the capping unit is communicated with the atmosphere by the valve.
Discharging the ink particles from the nozzle to the capping means, performing ink suction for adjusting the ink amount of the ink absorber of the capping means by the suction means, and then separating the capping means from the head. Features.

〔Example〕

FIG. 1 is an embodiment showing the main configuration of an ink jet recording apparatus according to the present invention. A carriage 3 on which the inkjet head 2 is mounted is guided and supported by a guide shaft 4, and the driving force of a motor 5 is transmitted to the carriage 3 via a timing belt 6, and the carriage 3 moves along a platen 7. The position of the carriage 3 is detected by a home position sensor 9 of a light emitting / receiving element provided at the left end portion, and is controlled based on a magnetic or optical encoder signal based on the home position. The recording signal is supplied to the inkjet head 2 via the flexible wiring 8.

The capping means 10 provided on the left side of the recording range includes a rubber cap 11 and a holding frame 12 for holding the cap, and an ink absorber 14 is provided in the space 13.

Reference numeral 21 denotes a pump as a suction means, and a space 13 is provided in a state where the tip of the ink jet head 2 is covered with the cap 11.
Can be sucked from the ink jet head 2 with a negative pressure, and at the same time, with the cap 11 opened, the ink in the space 13 is sucked to prevent dripping of excess ink. Is always adjusted to a constant ink amount determined by the ink holding power of the ink absorber.

Reference numeral 22 denotes a processing tank for processing ink overflowed from the pump 21.

FIG. 2 shows an embodiment of the capping means according to the present invention. FIG. 2 is a view seen from above, and when the carriage 3 moves to the left, the engaging portion 20 of the carriage 3 is moved by the capping means.
When the carriage 10 is retreated from the ink jet head 2 and the carriage 3 moves leftward, the capping means 10 moves in the direction of the ink jet head 2 and caps the nozzle 16 of the ink jet head 2 by the carriage position detecting means. When 11 covers, the carriage 3 stops. The spring 15 attaches the cap 11 to the inkjet head 2
Is a cap spring that urges the nozzle portion 16 so as to cover the nozzle portion 16 in an airtight manner.

When the carriage 3 moves rightward from the capping state to the recording range, the reverse operation is performed.

FIG. 3 shows another embodiment for moving the capping means 10 with respect to the ink jet head 2. The DC solenoid 19 is provided, and the capping means 10 is moved by controlling the energization.

When using black ink as recording ink, cap 11
And the ink absorber 14 is black. In the ink jet recording apparatus, a printing inspection is performed at the time of manufacturing and assembling, and ink droplets are ejected toward the space 13 during use as dictated by the use of the ink absorber 14 so that the ink becomes substantially the same color as the ink. By selecting the and the cap 11, the ink stains generated by the inspection when the ink cartridge is new are inconspicuous, and even after the start of use, the ink stains caused by the ejection of the ink particles can be used for a long time without being noticeable. .

FIGS. 4 and 5 show another embodiment of the capping means according to the present invention, and are sectional views as viewed from the direction of arrow 17 in FIG. A rubber cap 11 is fixed to a holding frame 12 made of a plastic molded product, and an ink absorber 14 is mounted in a space 13 of the cap 11. In FIG. 4, the ink absorber 14 is a space portion of the cap 11.
In FIG. 5, they are arranged in a plane so as to face the nozzles of the ink jet head, and in FIG.

6 and 7 show an embodiment of an operation flowchart of the ink jet recording apparatus according to the present invention.

As can be seen from FIG. 6, when the power of the recording apparatus is turned on, it is first verified whether or not the ink jet head 2 is at the cap position. If not, the head 2 is moved to the cap position and capped. Next, ink droplets of several tens to several hundreds of pulses are ejected from all the nozzles from the ink jet head 2 toward the above-mentioned space portion 13, and the ink is absorbed by the ink absorber 14 arranged in the space portion 13. The ink with increased viscosity at the nozzle tip generated during the idle period until the ink is supplied is discharged to prepare for ink discharge without discharge disturbance within the recording range. When the power is turned on, the nozzle portion of the ink-jet head is normally covered with a cap, and in consideration of preventing the above-described ejection of ink particles from repelling from the space portion 13, the nozzle portion of the ink-jet head is not covered with the cap. The ink droplets are ejected toward the portion.

When the recording signal is input, the capping means 10 moves away from the head, and at the same time, starts the pump and starts the timer, and the head starts recording. A few seconds of operation is sufficient for the pump to absorb excess ink in the cap.

Since the viscosity rise due to drying occurs in the nozzles that do not discharge even during printing, after counting the time set by the timer, for example, 5 minutes, when the carriage finishes printing one line, and starts a line feed, The nozzle moves to the cap position and discharges several to several tens of pulses of ink droplets from all the nozzles toward the aforementioned space. In this case, recording is often performed, and in the case of the embodiment shown in FIG. 3, ink is discharged while the cap 11 is retracted from the head by energizing the DC solenoid 19. At the same time, in the embodiment shown in FIG. 6, the pump is operated to discharge ink.

When the ink is ejected, the pump is stopped, the timer is reset, and the above operation is repeated until the recording command is lost and the cap is capped. After the capping, the ink discharge is stopped, and the timer is reset.

In FIG. 7, ink is ejected from all the nozzles toward the space inside the cap without necessarily opening the cap and the head starts to move to the recording range. Excluding the influence of drying at the nozzle portion, defective ejection in printing is prevented.

FIG. 8 schematically shows another embodiment of the capping means of the ink jet recording apparatus according to the present invention, and FIG. 9 is a flowchart showing the operation thereof. 25 is a valve,
The space 13 in the cap 11 is communicated with or cut off from the atmosphere through a tube 26. The space 13 is normally cut off from the atmosphere by a spring 27, and communicates with the atmosphere when a DC solenoid 28 is energized.

FIG. 7 describes the operation of discharging the ink toward the space when the cap is opened, but FIG. 9 (a) shows a further modification. When a recording command is input to the ink jet head in the capping state in the standby state, first, the valve 25 is turned on, and the space in the cap communicates with the atmosphere. Subsequently, the ink is discharged from all the nozzles while the pump is operated, and the ink having the increased viscosity at the nozzle tip is discharged, and at the same time, the ink absorber has a certain amount of ink determined by the ink holding power of the absorber and the suction force of the pump. Hold. Next, the inkjet head separates from the capping means, and then the valve shuts off from the atmosphere.
The pump stops the suction operation.

FIG. 3B shows a state where the space inside the cap is communicated with the atmosphere and the pump is suctioned after the ink is ejected.

With the configuration as shown in FIG. 8, the cap is separated from the head after suctioning the excess ink in the space in the cap, so that there is no need to worry about excess ink dripping from the space when the cap is opened. became.

〔The invention's effect〕

As described above, the capping unit that covers the nozzle portion of the inkjet head and has the ink absorber disposed in the internal space, the suction unit that communicates with the internal space of the capping unit, and the internal space of the capping unit An ink jet recording apparatus comprising a valve that communicates with or shuts off the nozzle unit, wherein the capping unit covers the nozzle unit, and the internal space of the capping unit is communicated with the atmosphere by the valve. While discharging ink droplets to the capping means,
Performing ink suction for adjusting the ink amount of the ink absorber of the capping means by the suction means, and thereafter separating the capping means from the head, that is, covering the nozzles with the capping means and communicating the inside with the atmosphere. In the state in which the ink is supplied to the porous material inside the capping means and the ink is ejected from the head for adjusting the ink amount and the ink is sucked in the cap,
Compared to the case where the cap and nozzle are separated from each other, it is possible to prevent ink from scattering to inappropriate places during ink ejection, without soiling the inside of the device and preventing ink stains on recording paper etc. it can.

In addition, in the case where the nozzles are covered with the cap in a state in which the nozzles are shielded from the atmosphere by the capping means, and the suction operation is performed after separating the nozzles and the capping means, the internal ink amount may not be an appropriate amount. In such a case, there is a problem that ink leaks when the cap is separated, but according to the present invention, such a problem can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a main part configuration of an ink jet recording apparatus according to the present invention. FIGS. 2 to 5 are diagrams showing an embodiment of a capping means according to the present invention.
FIGS. 7, 7 and 9 (a) and 9 (b) show an embodiment of an operation flowchart of the recording apparatus according to the present invention. 2 ... inkjet head 3 ... carriage 9 ... home position detection sensor 10 ... capping means 11 ... cap 12 ... holding frame 13 ... space 14 ... ink absorber 15 ... spring 19 ... actuator 25 ……valve

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 2/165

Claims (1)

(57) [Claims] An ink jet head that covers a nozzle portion of the ink jet head;
An ink jet recording apparatus comprising: a capping unit having an ink absorber disposed in an internal space; a suction unit communicating with the internal space of the capping unit; and a valve communicating or blocking the internal space of the capping unit with the atmosphere. And covering the nozzle portion with the capping means,
In addition, in a state where the internal space of the capping unit is communicated with the atmosphere by the valve, ink droplets are ejected from the nozzle to the capping unit, and ink for adjusting the amount of ink in the ink absorber of the capping unit. An ink jet recording apparatus, wherein suction is performed by the suction unit, and thereafter, the capping unit is separated from the head.