JPH04232069A - Ink jet printer - Google Patents

Abstract

PURPOSE:To make an ink supply amount appropriate by adjusting a pressure in an ink cartridge to a proper level, if the pressure becomes negative. CONSTITUTION:An air ventilation hole 4a is formed in an ink cartridge 4, and a valve 7 for closing this air ventilation hole is provided. If a pressure in the ink cartridge 4 becomes negative due to ink consumption, the valve 7 opens automatically to make the pressure in the cartridge equal to an atmospheric pressure. If the pressure in the ink cartridge 4 is at the same level as the atmospheric pressure, the valve returns to its home position automatically to close the air ventilation hole 4a. A shut-off device of the air ventilation hole is of a simple structure, seldom fails, and can be manufactured and supplied at low cost.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet printer.

0002

2. Description of the Related Art As is well known, inkjet printers continuously supply ink to the print head during recording operations, or perform recovery operations such as removing air bubbles from nozzles when the carriage is at the home position. When printing, negative pressure is generated within the ink cartridge, resulting in insufficient ink supply to the print head, resulting in poor printing.

[0003] Conventionally, therefore, ink cartridges of inkjet printers are provided with vents that communicate with the atmosphere to prevent negative pressure from occurring. However, when a carriage carrying an ink cartridge remains in the home position for a long time, there is a risk that the ink stored in the ink cartridge may dry out or dust may enter through the ventilation holes. For this reason, some devices include a means for blocking the air hole, which is disposed in the main body of the recording apparatus, and blocks the air hole of the ink cartridge when the carriage is at the home position. This shutoff means is configured to open and close the ventilation hole by electromagnetic operation (
(Japanese Patent Application Laid-open No. 61-5948).

[0004] Another shutoff means includes a magnetic body that can open and close the ventilation hole of the ink cartridge, and when the carriage returns to the home position, the magnetic body is operated by a magnet disposed on the main body of the recording apparatus. The structure is such that the ventilation hole is closed (Japanese Unexamined Patent Publication No. 63-247048).

[0005]

However, in the former method, the means for communicating the ink cartridge with the atmosphere during the recovery operation of the print head is an electromagnetic device, so the device is complex, large-sized, and costly.

Furthermore, in the latter case, when the carriage is at the home position, the ink cartridge does not communicate with the atmosphere, so negative pressure is generated in the ink cartridge during the nozzle recovery operation, and a sufficient effect cannot be obtained. Even if electromagnetic means were provided as means for blocking the vent, it would have the same drawbacks as the former.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the size, simplify, and inexpensively manufacture and supply a means for blocking the vent from the atmosphere by making the vent blocking means a valve structure.

[0008]

[Means for Solving the Problems] The present invention is characterized in that the blocking means for opening and closing the communication hole that communicates with the ink cartridge and the atmosphere is capable of blocking the ventilation hole from the atmosphere;
The ink cartridge is equipped with a valve that automatically opens when the pressure inside the ink cartridge becomes negative.

[0009]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a state in which the carriage 1 is located at the home position. When the carriage 1 performs a printing operation, it is guided by the carriage guide 2, moves left and right, and is inserted between the carriage 1 and the platen 3. The information is printed on recording paper (not shown). On the carriage 1 are an ink cartridge 4 and a print head 5.
is mounted on the tip of the print head 5,
A nozzle 6 protrudes, and ink in the ink cartridge 4 is supplied to this nozzle, and the ink is ejected from this nozzle to perform printing.

A vent hole 4a communicating with the atmosphere is provided in the upper part of the ink cartridge 4, and a valve 7, which normally closes this vent hole, is provided as a means to isolate this vent hole from the atmosphere. It is being

The valve 7 is a rectangular member made of a flexible material, and as shown in FIG. The valve is usually fixed from this fixed part to the left side.
It comes into contact with the inner peripheral surface of the ventilation hole 4a and closes this ventilation hole. A sponge 8 impregnated with ink is housed in the ink cartridge 4.

Further, as shown in FIG. 1, when the carriage 1 is located at the home position, the open end of the cap 9 covers the periphery of the nozzle 6. Then, the pump P connects this nozzle 6 through the tube.
A recovery operation is performed to suck out ink and air bubbles from the ink.

Next, the operation of the present invention will be explained. During printing, the ink contained in the sponge 8 in the ink cartridge 4 is supplied to the nozzle 6, and the ink is ejected from this nozzle to perform printing. When the ink in the print head 5 is consumed, ink is supplied from the ink cartridge 4 in an amount equal to that amount. Furthermore, when performing the recovery operation of the nozzle 6, ink and air bubbles are sucked from the nozzle 6 by the cap 9.

In either case of printing or recovery operation, the ventilation hole 4a of the ink cartridge 4 is always in the position shown in FIG.
As shown by the solid line, the air pressure inside this ink cartridge gradually decreases because the valve 8 is closed and the ink cartridge is in a sealed state. When the air pressure inside the ink cartridge 4 becomes negative, the valve 3 bends inward of the ink cartridge 4 due to its flexibility as shown by the chain line in FIG.
Therefore, the ventilation hole 4a is automatically opened. In this way, when the vent hole 4a is automatically opened by natural action, air enters and the pressure inside the ink cartridge 4 becomes equal to atmospheric pressure, so the valve 8 is automatically returned to the closed position. The state returns to the state shown by the solid line in FIG.

Next, another embodiment of the vent blocking means according to the present invention will be described. As shown in FIG. 3, the ink cartridge 41 has a plurality of ventilation holes 41a, 41a, and a locking hole 41b is formed in the center surrounded by the ventilation holes. The valve 71 is made of a flexible material as in the previous embodiment, and its cross-sectional shape is in the shape of an arrow pointing downward, and the valve is locked in this locking hole. A valve portion 71a integrally formed at the lower end of the valve 71 normally closes the ventilation hole 41a. Further, the ink cartridge 41 houses a sponge 81 impregnated with ink.

When the ink in the ink cartridge 41 is consumed and the pressure becomes negative, the valve part 71a bends inward of the cartridge 41 as shown by the chain line due to its flexibility, and both vent holes 41a are bent. , 41a. When the pressure inside the ink cartridge 41 becomes equal to the atmospheric pressure, it automatically returns to close the vent holes 41a, 41a.

FIG. 4 shows yet another embodiment, in which an ink cartridge 42 is provided with a ventilation hole 42a, and a holding portion 42b is integrally formed within this cartridge. The valves 72a and 72b are composed of two parts, and one end of each is held between the holding parts. The ink cartridge 42 also houses a sponge 82 impregnated with ink.

When the inside of the ink cartridge 42 becomes negative pressure, the valve portions 72a and 72b bend inward of the cartridge 42 due to their flexibility, as shown by the chain lines, and open the vent hole 42a. and ink cartridge 42
When the internal pressure becomes equal to the atmospheric pressure, it automatically returns to close the vent hole 42a.

Still another embodiment will be described with reference to FIGS. 5 and 6. A feature of this embodiment is that the ventilation hole blocking means is installed at the home position rather than inside the ink cartridge 4 as in the previous embodiments. In this embodiment, the ink in the ink cartridge 4 evaporates through the ventilation hole 43a, or foreign matter enters the ink cartridge, which is most noticeable when the ink cartridge 4 returns to the home position, which is when the air vent 43a is stopped. It was invented based on the idea that it would be sufficient to block 7.

In FIGS. 5 and 6, a carriage 1 slides while being guided by a guide 2. An ink cartridge 43 and a print head 5 are mounted on this carriage. A sponge 83 impregnated with ink is housed, and a ventilation hole 43a is provided on the side of the cartridge.

The printer frame (not shown) is provided with a mounting frame 10 having a valve chamber inside, a second ventilation hole 10a is opened in this mounting frame, and one end of the valve 73 is opened in this mounting frame. A clamping part 10b for fixing the valve chamber is integrally formed, and the valve 73 is fixed thereto, and an elastic member 11 is fixed to the open end of the valve chamber.

In this case, when the carriage 1 returns to the home position, the ink cartridge 4 on the carriage 1
The elastic member 1 of the mounting frame 10 is placed around the ventilation hole 43a of No. 3.
1 will come into contact. Therefore, the vent hole 43a is shielded from the atmosphere. At the home position, when the nozzle 6 undergoes a recovery operation by the cap 9 and the ink in the ink cartridge 43 is consumed to become a negative pressure, the valve 73, due to its flexibility, is attached to the mounting frame 10 as shown by the chain line. Bent toward the chamber, the ventilation hole 43a, the second ventilation hole 1
Open with 0a in communication. After that, when the pressure inside the ink cartridge 43 becomes equal to the atmospheric pressure, the valve 73 automatically returns to close the second vent hole 10a.

Still another embodiment will be described with reference to FIG. 7. The carriage 1 is equipped with an ink cartridge 44 and a print head, and inside the ink cartridge is a sponge 84 impregnated with ink. is housed therein, and an insertion hole 44a is formed on the side of the cartridge. Further, the printer frame (not shown) is provided with a holder 12 at the home position.
This holder 12 is provided with a valve mounting frame 13, the inside of this valve mounting frame is a valve chamber, and a second ventilation hole 13a is opened in this valve mounting frame. One end of a valve 73 is fixed in the valve chamber of the mounting frame 13 to open and close the second ventilation hole 13a. Furthermore, holder 12
A cap 91 is attached to the nozzle 61, and this cap is provided with a pump as shown in FIGS. 1 and 5 to perform a recovery operation of the nozzle 61.

Therefore, in the home position, when the nozzle 61 undergoes a recovery operation by the cap 91 and the ink in the ink cartridge 44 is consumed and becomes negative pressure, the valve 74, due to its flexibility, closes in the valve chamber of the mounting frame 13. The vent hole 44a and the second vent hole 13a are opened in a state where they are in communication with each other. After that, when the pressure inside the ink cartridge 44 becomes equal to the atmospheric pressure, the valve 74 automatically returns to close the second vent hole 13a.

In each of the above embodiments, a sponge impregnated with ink is stored in the ink cartridges 4, 41, 42, 43, 44. A bag containing ink can also be placed inside.

[0026]

[Effects of the Invention] By using a valve structure as the vent blocking means, the present invention has a simpler structure compared to the conventional vent blocking means using electromagnetic means or magnetic material, and can therefore be miniaturized. Furthermore, since it has a simple configuration, it is less likely to break down and can be manufactured and supplied at low cost.

[Brief explanation of the drawing]

FIG. 1 A partially cutaway plan view of an embodiment of the present invention.

[Figure 2] Cross-sectional view taken along line a-a in Figure 1

[Fig. 3] Enlarged sectional view showing another embodiment

[Fig. 4] Enlarged sectional view showing another embodiment

[Fig. 5] Partially cutaway plan view showing another embodiment

[Figure 6] Figure 5
Enlarged sectional view of the embodiment shown in

[Fig. 7] Partially cutaway front view showing still another embodiment

[Explanation of symbols]

1 Carriage 4 Ink cartridge 4a Ventilation hole 5 Print head 6 Nozzle 7 Valve 8 Ink 9 Cap 41 Ink cartridge 41a Ventilation hole 71 Valve 42 Ink cartridge 42a Ventilation hole 72a, 72b valve 43 Ink cartridge 43a, 10a Ventilation hole 73 Valve 44 Ink cartridge 44a, 13a Ventilation hole 74 Valve

Claims (3)

[Claims] 1. An inkjet printer that guides ink in an ink cartridge to a print head mounted on a carriage and ejects the ink from a plurality of nozzles of the print head toward recording paper. A valve-type shutoff means is provided with a communication hole that communicates with the ink cartridge, and is capable of shutting off this vent hole from the atmosphere, and is equipped with a valve that automatically opens due to negative pressure when the inside of the ink cartridge becomes negative pressure. An inkjet printer characterized by being provided with. 2. The ink jet printer according to claim 1, wherein the valve type shutoff means is provided in the ink cartridge. 3. In claim 1, the ink cartridge is mounted on the carriage together with the print head, and the valve-type shutoff means is provided in the printer main body,
An inkjet printer characterized in that a vent hole of the ink cartridge is closed when the carriage is located at a home position.