JPH0684081B2 - Discharge recovery method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a discharge recovery method, and more specifically, to a discharge recovery operation by negative pressure suction on an orifice portion of a liquid jet recording apparatus that discharges liquid as flying droplets. The present invention relates to a discharge recovery method to be performed.

[Prior Art] A liquid jet recording apparatus applies a pressure corresponding to a recording signal to a liquid such as ink filling a liquid flow path, and ejects the liquid from an orifice formed at the tip of the liquid flow path to generate droplets. Is a recording apparatus that performs dot recording on a recording medium by discharging the ink as a recording medium and is also called an inkjet printer.

In this type of liquid jet recording apparatus, when a recording head having one or a plurality of orifices is subjected to a mechanical shock or a sudden temperature change, air enters the liquid flow path. Or, the dissolved gas in the liquid is generated and the normal meniscus is destroyed, and the droplets are no longer ejected according to the recording signal, or even if they are ejected, the droplets are called splash, satellite, etc. Further, a defective print state occurs in which the particles are dispersed.

Then, in order to recover such a non-ejection state or defective printing, an ejection recovery mechanism is provided which recovers a normal meniscus by sucking ink from the orifice side with a negative pressure.

This ejection recovery mechanism is provided, for example, at the home position part of the recording head, and is provided with a cap that is brought into close contact with the orifice part when the recording head returns to the home position, and this cap is fitted to the orifice part. Then, negative pressure suction is performed and the liquid is sucked from the orifice portion to form a normal meniscus.

1 to 3 show a schematic structure of a conventional discharge recovery mechanism of this type.

In each figure, reference numeral 1 indicates a sub-tank provided on a carriage (not shown), and a plurality of orifices 2 (multi-orifice) are provided at the tip of the sub-tank 1.
Are formed.

A liquid such as ink is constantly supplied to the sub tank 1 from a main tank (not shown), and the orifice 2
The liquid can be constantly supplied into the liquid flow path continuous to the side.

On the other hand, a discharge recovery mechanism is provided on the fixed portion side of the device. The ejection recovery mechanism has a cap 3, and an elastic member 4 is housed in the cap 3. A recess 7 is formed at the tip of the elastic member 4, and the recess 7 is connected to the negative pressure suction pump 6 via the tube 5.

In the above-described configuration, in order to perform the discharge recovery operation, the cap 3 is advanced with the orifice 2 portion facing the cap 3, and the elastic member 4 is pressed so as to surround the entire orifice 2. The pressure suction pump 6 is operated to bring the inside of the recess 7 into a negative pressure state via the tube 5,
Liquid is sucked from the orifice 2.

By such an operation, as described above, the meniscus is restored to the normal state and the normal recording can be performed.

However, the use of the negative pressure discharge recovery mechanism having the above structure has the following drawbacks.

That is, the cap 3 is closely attached so as to surround the orifice 2, capping is performed, negative pressure suction is performed, and then the ink 8 sucked as shown in FIG. And the elastic member 4 side are pulled by surface tension respectively.

At this time, even if the liquid is made water-repellent so that droplets do not adhere to the periphery of the orifice 2 side, a part of the liquid remains, and a liquid pool 9 is formed around the orifice 2 as shown in FIG.

When the liquid pool 9 is generated at the tip of the orifice 2 as described above, a non-ejection state or an unstable ejection state often occurs.

In such a phenomenon, in the multi-orifice type recording head, since the opening area of the concave portion 7 of the elastic member 4 becomes extremely large, it becomes difficult to hold the liquid, and more liquid pool 9 is generated on the orifice 2 side. .

[Object] The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and an object of the present invention is to provide a discharge recovery method in which liquid is not accumulated on the orifice side when capping is opened. .

In the present invention, in order to achieve the above object, a cap that can be in a capping state for capping an orifice of an inkjet head for ejecting ink and an open state for opening the orifice, and a cap disposed on the cap, An ejector recovery method for an inkjet apparatus, comprising: an absorber capable of contacting an orifice surface of the inkjet head provided with the orifice, wherein the capping is performed by the cap so that the absorber contacts the orifice surface. A step of discharging ink from the orifice through the cap when the cap is in the capping state, and ending the discharge of ink from the orifice, and then releasing the ink from the capping state to the open state. Move the cap to And a step of discharging the ink that has been absorbed by the absorber and remains when the cap is in the open state.

[Examples] Hereinafter, details of the present invention will be described based on Examples shown in the drawings.

4 and 5 illustrate one embodiment of the present invention. In each figure, the same parts as those in FIGS. 1 to 3 are designated by the same reference numerals, and the description thereof will be omitted.

In this embodiment, as shown in FIG. 4, a liquid absorber 10 is provided in a recess 7 formed at the tip of an elastic member made of rubber or synthetic resin provided in the cap 3.

As the absorber 10, a porous material such as foamed synthetic resin is adopted.

Once the absorber 10 is wetted by the liquid, the liquid used in the liquid jet recording apparatus is very difficult to dry, and can continue to swell for several months at room temperature.

It goes without saying that the entire cap 3 may be made of an elastic member.

Based on the above structure, the ejection recovery operation is actually performed as follows.

FIG. 5 is a timing chart for explaining the operation of the discharge recovery mechanism according to the present invention. First, when the orifice 2 comes to a position facing the cap 3, first the cap 3 advances and the absorber 10 moves to the orifice 2. Start contact.

At the time of this first contact, the absorber 10 has a sufficient elasticity and therefore has a cushioning action, and the absorber 10 contacts the orifice 2 side before the cap 3 is sealed. Therefore, the problem that the air in the cap 3 is compressed and enters the orifice 2 side does not occur.

After the absorber 10 is compressed and the elastic member 4 and the orifice 2 are brought into close contact with each other, the absorbing operation is performed as shown in FIG. This absorbing operation is performed manually or automatically by operating a pump or the like.

After this negative pressure suction operation is performed, the cap 3 is separated from the orifice 2 side. Then, as soon as the cap 3 is released, empty suction is performed.

By performing this empty suction, the liquid contained in the absorber 10 is also sucked, and the excess liquid does not exist in the absorber 10. Therefore, the inconvenience such as the liquid in the absorber 10 being dried does not occur.

The state in which the empty suction is completed is indicated by reference character A in FIG.

Subsequently, the cap 3 further advances, and the cap 3 is brought into close contact with the orifice 10 for a short time, so that the absorber 10 contacts the orifice 2.

Therefore, even if a liquid pool exists on the orifice 2 side, the liquid pool can be completely absorbed by the absorber 10 by the second contact.

As a result of performing the idle suction and the capping operation again in this way, it was possible to completely eliminate the occurrence of the liquid pool, and the non-ejection state did not occur at all.

The time point when the discharge recovery operation is completely completed is shown by reference character B in FIG.

It was also found that the capping operation again is not always necessary, and if the function of the absorber 10 is perfect, one cycle of the discharge recovery operation may be completed at the stage of empty suction.

[Effect] As is apparent from the above description, according to the present invention, a cap that can be in a capping state for capping an orifice of an inkjet head for ejecting ink and an open state for opening the orifice, and the cap A discharge recovery method for an inkjet device, comprising: an absorber disposed on the ink jet head, the absorber being capable of contacting the orifice surface of the ink jet head, wherein the cap is disposed so that the absorber contacts the orifice surface. Performing the capping by means of, and discharging the ink from the orifice through the cap when the cap is in the capping state,
Ending the discharge of ink from the orifice, and then moving the cap from the capping state to the open state; and removing the ink absorbed and left in the absorber when the cap is in the open state. Since the ejection recovery method including the step of ejecting the ink is adopted, the ejection of the recovery ink (main suction) and the ejection of the ink absorbed by the absorber and remaining (empty suction) are performed extremely stably. Therefore, it is possible to reliably prevent the liquid pool on the orifice side, and to reliably prevent defective ejection and non-ejection.

[Brief description of drawings]

1 to 3 are diagrams for explaining a conventional structure. FIG. 1 is a schematic configuration diagram illustrating a discharge recovery mechanism, FIG. 2 is a schematic configuration diagram illustrating a state when capping is released, and FIG. An explanatory view showing a state in which a liquid pool is formed, FIGS. 4 and 5 are for explaining one embodiment of the present invention, FIG. 4 is a schematic configuration diagram for explaining a discharge recovery mechanism, and FIG. It is a timing chart figure explaining discharge recovery operation. 1 ... Sub tank, 2 ... Orifice 3 ... Cap, 4 ... Elastic member 5 ... Tube, 6 ... Negative pressure suction pump 7 ... Recess, 8 ... Ink 9 ... Liquid pool, 10 ... Absorption body

Claims (2)

[Claims] 1. A cap which can be in a capping state for capping an orifice of an ink jet head for ejecting ink and an open state for opening the orifice, and a cap disposed on the cap, the orifice of the ink jet head being provided. A method for recovering discharge of an ink jet device, comprising: an absorber capable of contacting an orifice surface, the step of capping with the cap so that the absorber contacts the orifice surface; Discharging ink from the orifice through the cap when in the state, and ending the discharge of ink from the orifice, then moving the cap from the capping state to the open state, The cap is in the open state And a step of discharging the ink that has been absorbed by the absorber and remains. 2. The method according to claim 1, further comprising the step of shifting the cap from the open state to the capping state after discharging the ink absorbed and retained by the absorber. The ejection recovery method according to the item.