JP3487331B2 - Ink jet recording device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mounts a recording head and a sub tank unit on a carriage that moves in the width direction of a recording sheet, and prints on a recording medium while supplying ink from an ink cartridge via an ink supply tube. The present invention relates to an inkjet recording apparatus that performs

[0002]

2. Description of the Related Art Among ink jet type recording apparatuses for recording print data by ejecting ink pressurized in a pressure generating chamber as ink droplets from a nozzle onto recording paper, it is used in a large amount of printing. In this case, a large ink cartridge is installed in the box and ink is supplied to a sub tank unit connected to the recording head via an ink supply tube. The sub-tank unit has a filter function for separating the ink inlet port and the ink outlet port, in addition to the damper function for preventing the pressure variation of the ink due to the movement of the carriage as seen in, for example, JP-A-5-201015. It is also arranged vertically and has a function of filtering and eliminating bubbles and dust contained in the ink from the ink supply means such as the ink cartridge and the ink container.

[0003]

By the way, in order to improve the printing quality of color printing, inks with less bleeding compared with conventional inks, so-called slow penetrating inks are being adopted, and high-speed printing is possible. Therefore, the nozzle numerical aperture of the recording head is increased to 3 to 4 times that of the conventional one. Since such a slowly penetrating ink has high surface tension, when the filter is immersed in the ink due to the vertical movement of the ink surface or is exposed to the air, bubbles are formed in the ink due to the pores forming the filter. It is apt to occur, and there is a problem that the air bubbles flow into the recording head during printing to deteriorate the print quality. The present invention has been made in view of such circumstances, and an object thereof is an ink jet recording capable of preventing generation of bubbles in a filter and preventing bubbles from entering a recording head. It is to provide a device.

[0004]

In order to solve such a problem, in the present invention, a memory mounted on a carriage is used.
And recording head, the ink supply from the ink cartridge through the ink supply tube is mounted on the carriage
In response to this, the ink pressure changes due to the reciprocating movement of the carriage.
Damper area that absorbs motion, and below the damper area
Placed horizontally to block the passage of air bubbles in the ink
And a filter for supplying the recording head to the recording head.
The nozzle unit of the recording head and the nozzle unit of the recording head.
Cap member and a suction member that supplies a negative pressure to the cap member.
Back and forth between the suction pump and the ink supply tube.
And a vibrating means for imparting motion to seal the recording head.
Then operate the suction pump to insert it into the recording head.
When charging
The ink supply tube was so that moved back and forth.

[0005]

Under section than [action] filter damper region, and since it is arranged horizontally, regardless filter to variations in the ink liquid surface is not exposed to the air, during printing
Preventing generation of bubbles due to the exposure of the filter, also the ink
Bubbles in the flow path such as the ink supply tube are filled when filling
It can be released from the surface and discharged reliably .

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the present invention will be described below with reference to illustrated embodiments. FIG. 1 shows an embodiment of the ink jet recording apparatus of the present invention,
The carriage 1 is connected to the motor 3 by the timing belt 2 and is configured to be guided by the guide member 4 and move parallel to the platen 5. A recording head 6 is mounted on the surface of the carriage 1 facing the recording paper,
A sub tank unit 7 having a damper function and a filtering function is placed on the upper surface.

An ink cartridge 9 is housed on one side of the frame 8 and is connected to a sub tank unit 7 described later by an ink supply tube 10.

A capping device 12 provided with a cap member 11 for sealing the nozzle openings of the recording head 6 is arranged in the non-printing area of the movement path of the recording head 6, and a negative pressure from a pump unit 13 is supplied. There is.

FIG. 2 shows an ink supply system in the recording apparatus using one ink cartridge 9 as an example. The sub-tank unit 7 has an ink inlet 14 provided by an ink supply tube 10 to the ink cartridge 9. Further, the ink outlet port 15 is connected to the ink supply pipe 16 of the recording head 6.

A cap member 11 for sealing the recording head 6.
Is connected to the suction port 18a of the tube 18 constituting the pump unit 13, and the discharge port 18b of the tube 18
The side is communicated with the waste ink tank 19.

3 (a) and 3 (b) show an embodiment of the sub tank unit 7 described above.
A concave portion 21 having an opening on one surface is formed, and an ink inlet 14 is formed on the side wall portion and a concave portion 22 is formed on the lower side so as to communicate with the concave portion 21 and a filter 23 is horizontally stretched on the opening. Further, the ink outlet port 15 is formed at the bottom, and the opening of the recess 21 is sealed by the elastic film 24 having a high gas-shielding property that can be deformed by the pressure of the ink so that the filter 23 faces the damper region, that is, the elastic film 24. It is configured so as to be located below the area to be opened.

In this embodiment, when the ink cartridge 9 is newly installed, the pump unit 13 is operated when an initial filling command is issued by a switch of a control panel provided on the surface of the recording device box. The negative pressure of the pump unit 13 acts on the sub-tank unit 7 and the ink supply tube 10 that form the ink supply flow path via the recording head 6, and the ink of the ink cartridge 9 passes through the ink supply tube 10 to the sub-tank. Pull into unit 7.

The air in the sub-tank unit 7 is attracted by the strong suction force of the pump unit 13, passes through the filter 23, flows into the recording head 6 via a part of the ink supply pipe 16 of the recording head 6, and prints. It is discharged from the head 6 to the cap member 11.

After the operation of the pump unit 13 is stopped, the sub tank unit 7 is supplied with the same amount of ink as the amount of air flowing out from the sub tank unit 7 during the suction operation. As a result, the liquid level of the ink in the sub-tank unit 7 rises, and the filter 23 located below the damper area is located below the liquid level of the ink.

As described above, since the ink inlet 14 of the sub-tank unit 7 is located below the ink surface and the ink surface is located in the center of the damper area, It is possible to prevent bubbles from being generated even if the liquid level of the liquid is slightly lowered.

When a print signal is input at the stage where the ink filling is completed, the bubbles generated in the ink cartridge 8 and the ink supply tube 9 are positioned below the ink surface with a weak suction force which is about ink consumption for printing. However, it is extremely difficult to pass through the filter 23 immersed in the ink, so that it cannot enter the recording head 6.

Further, when the liquid surface of the ink flowing from the ink tube 10 moves up and down due to the movement of the carriage 1 and the pressure fluctuates, the elastic film 24 deforms and absorbs the pressure fluctuation, so that it is supplied to the recording head 6. The ink pressure is kept constant and high-quality printing is possible. Furthermore, since the filter 23 is immersed in the ink regardless of the fluctuation of the ink surface, the generation of bubbles due to the pores of the filter 23 is suppressed.

However, particularly in a recording apparatus using an ink having a high surface tension such as a slow penetrating ink,
It is extremely difficult to discharge the air bubbles stuck to the ink supply tube 10 and the inner wall of the sub tank unit 7, and further to the filter 23 by the ink filling operation, and if these air bubbles are released by the impact caused by the movement of the carriage during printing. However, it may flow into the recording head and cause printing failure.

FIG. 4 shows an embodiment capable of solving such a problem. In this embodiment, an eccentric weight is rotated on the ink supply tube 10 by vibrating means 28, for example, a motor. A mechanism, an AC-excited solenoid, a linear motor, and the like are connected via an arm.

According to this embodiment, the pump unit 13
By operating the vibrating means 28 in parallel with the suction operation by, the ink supply tube 10 as well as the sub tank unit 7 connected thereto is vibrated, and the ink supply tube 10 and the inner wall of the sub tank unit 7 and the filter 23 are vibrated. The sticking air bubbles are released, and the air bubbles released by the rapid flow of the ink due to the strong suction force of the pump unit 13 pass through the recording head 6 and the cap member 11
Can be discharged.

The vibrating means 2 is used in the above embodiment.
Although the vibration is applied by 8, the same effect can be obtained by connecting the electromagnetic valve 29 to the ink supply tube 10 and intermittently opening and closing the ink supply path.

According to this embodiment, the pump unit 13
If the electromagnetic valve 29 is opened and closed intermittently in parallel with the suction operation by the ink supply tube 10, the ink supply tube 10 vibrates due to the water hammer action of the ink supply tube 10 and its elasticity.
In the same manner as described above, the bubbles in the flow path are released and the cap member 1
1 can be discharged.

Further, even if the carriage 7 is reciprocally moved to such an extent that the sealing of the recording head 6 by the cap member 11 is not damaged, the ink supply tube 10 connected to the carriage 7 can be vibrated. Therefore, it is possible to release the bubbles in the flow path and discharge them to the cap member 11.

Although the damper chamber and the filter chamber are formed in the same recess 21 of the sub-tank unit 7 in the above embodiment, one surface of the base 30 is opened as shown in FIG. Forming a concave portion 31 as a portion, the ink inlet port 14 is formed in the side wall portion and the connection port 32 is formed in the bottom portion so as to communicate with the concave portion 31, and the opening of the concave portion 31 can be deformed by the pressure of the ink and has a high air-shielding property. A damper tank 34 formed by sealing with an elastic film 33 and a filter chamber 35 having a rhombic cross section in the center are horizontally arranged with a filter 36, and a connection port 37 is provided at an upper end and a lower end of the filter chamber 35, respectively. And the filter member 3 having the ink outlet 15 formed therein.
It is also possible to connect 8 and 8 in a vertical relationship.

According to this, since the degree of freedom in design is increased, the respective functions of the damper tank 34 and the filter member 38 can be enhanced.

Then, as shown in FIGS. 6A and 6B, a recess 40 having a communication hole in the lower surface of the damper tank 34.
Further, a convex portion 41 having a communication hole is provided on the upper surface of the filter member 38, a packing 42 such as an O-ring is fitted in the concave portion 42, or a convex portion 43 having a communication hole is formed on the lower surface of the damper tank 34. Also, a recess 44 having a communication hole is provided on the upper surface of the filter member 38, and the packing 4 such as an O-ring is provided in the recess 44.
5 is fitted, the damper tank 34 or the filter member 38 can be individually replaced while ensuring the airtightness of the connection portion, and the maintenance work can be simplified.

[0027]

As described above, according to the present invention ,
Filter under section than the damper region, and horizontally disposed
Therefore, the filter can be used regardless of the fluctuation of the ink surface.
Filter during printing without exposure to air
Prevents the generation of bubbles due to the exposure of the
Bubbles in the flow path of the ink supply tube etc. can be played from the wall surface of the flow path.
Can be separated and discharged reliably.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an ink jet recording apparatus of the present invention.

FIG. 2 is a diagram showing an example of an ink supply system of the ink jet recording apparatus.

3A and 3B are a front view and a cross-sectional view, respectively, showing an embodiment of a sub tank unit.

FIG. 4 is a diagram showing another embodiment of the ink jet recording apparatus of the present invention.

5A and 5B are a front view and a cross-sectional view showing another embodiment of the sub tank unit.

6A and 6B are front sectional views showing another embodiment of the sub tank unit.

[Explanation of symbols]

1 carriage 6 recording head 7 sub tank unit 9 ink cartridges 11 Cap member 14 ink inlet 15 Ink outlet 23 Filter 24 Elastic membrane

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-9-286115 (JP, A) JP-A-9-207354 (JP, A) JP-A-7-276671 (JP, A) JP-A-5- 8400 (JP, A) JP 11-115212 (JP, A) JP 10-296996 (JP, A) JP 4-25466 (JP, A) JP 8-112905 (JP, A) Actual Kaihei 1-76236 (JP, U) Registered utility model 3046244 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41J 2/175 B41J 2/165 B41J 2/18 B41J 2 / 185

Claims (8)

(57) [Claims] 1. A recording head mounted on a carriage,
A damper region that is mounted on the carriage and receives ink supplied from an ink cartridge through an ink supply tube, and absorbs a pressure fluctuation of the ink due to the reciprocating movement of the carriage, and is arranged horizontally below the damper region. A sub-tank unit that has a filter that blocks passage of bubbles in the ink and supplies the recording head to the recording head, a cap member that seals a nozzle opening of the recording head, and a suction that supplies a negative pressure to the cap member. A pump, and a vibrating unit that reciprocates the ink supply tube to apply vibration, and in the case of sealing the recording head and operating the suction pump to fill the recording head with ink, An ink jet recording apparatus which operates a vibrating means to reciprocate the ink supply tube. 2. A recording head mounted on a carriage,
A damper region that is mounted on the carriage and receives ink supplied from an ink cartridge through an ink supply tube, and absorbs a pressure fluctuation of the ink due to the reciprocating movement of the carriage, and is arranged horizontally below the damper region. A sub-tank unit that has a filter that blocks passage of bubbles in the ink and supplies the recording head to the recording head, a cap member that seals a nozzle opening of the recording head, and a suction that supplies a negative pressure to the cap member. A pump and a valve connected in the middle of the ink supply tube are provided, and when the recording head is sealed and the suction pump is operated to fill the recording head with ink, the valve is opened and closed. An ink jet recording apparatus which gives a water impact to the ink supply tube. 3. A recording head mounted on a carriage,
A damper region that is mounted on the carriage and receives ink supplied from an ink cartridge through an ink supply tube, and absorbs a pressure fluctuation of the ink due to the reciprocating movement of the carriage, and is arranged horizontally below the damper region. A sub-tank unit that has a filter that blocks passage of bubbles in the ink and supplies the recording head to the recording head, a cap member that seals a nozzle opening of the recording head, and a suction that supplies a negative pressure to the cap member. A pump, which seals the recording head with the cap member and operates the suction pump to fill the recording head with ink, while maintaining the sealing state of the recording head with the cap member. An ink jet recording apparatus that reciprocates a carriage to vibrate the ink supply tube. 4. The sub-tank unit has a recess formed in a base, a filter is horizontally provided in a region below the recess, and the recess is sealed with an air-permeable elastic film that can be deformed by ink pressure. The inkjet recording apparatus according to any one of claims 1 to 3, which is configured. 5. The ink outlet of the sub-tank unit is arranged in the damper region, and the ink outlet of the sub-tank unit is arranged below the filter. Inkjet recording device. 6. The ink inlet of the sub-tank unit is arranged above the filter and below the center of the damper region of the sub-tank unit. Inkjet recording device. 7. A damper tank in which a recess is formed in a base of the sub-tank, and the recess is sealed with an air-permeable elastic film that can be deformed by ink pressure, and a filter in which a filter is horizontally arranged in a filter chamber. The ink jet recording apparatus according to any one of claims 1 to 3, wherein a member and a member are connected so that the damper tank is located above. 8. The ink jet recording apparatus according to claim 7, wherein the sub-tank and the filter member are configured to be detachable by a joining member.