JP2002292885A - Ink drying prevention device, ink recording head storage container, ink jet recorder and method for preventing ink from drying - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink drying prevention device which can surely prevent ink from drying for a long term by tightly adhering a cap member to an ink ejection face and prevent the air from being pressed into nozzles, an ink jet recording head storage container to which the ink drying prevention device is applied, an ink jet recorder, and a method using the ink driving preventing device for preventing ink from drying. SOLUTION: The ink drying prevention device 102 is provided with a convex meniscus formation means 107 for forming convex meniscuses 22 to ink ejection openings 16 at least before an adhering member 104 adheres to the ink ejection face 14. The air in the nozzles 18 is faced to the outside by forming the convex meniscuses 22. As a result, the adhering member 104 adheres to the ink ejection face 14 in a state with no air present in the nozzles 18 and seals the ink ejection openings 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ink drying prevention device, an ink jet recording head storage container provided with the ink drying prevention device, an ink jet recording device, and an ink drying prevention method using the ink drying prevention device.

[0002]

2. Description of the Related Art An ink jet recording apparatus ejects ink as ink droplets in accordance with image information from an ink discharge port formed on an ink discharge surface of an ink jet recording head, and adheres the ink droplet to a recording medium to perform printing ( Image recording). In such an ink jet recording apparatus, if a state in which printing is not performed continues for a long time, the ink dries and clogs the nozzles (ink flow path), or dust (dust) adheres to the ink ejection surface, so Missing dots may occur, resulting in poor print quality or impossible printing. Therefore, when printing is paused for a certain period, when printing with ink of different colors,
Alternatively, when the recording method is changed, the recording head is moved to a predetermined position in the ink jet recording apparatus, and the ink is prevented from being inadvertently dried by the ink drying prevention device. Further, the used recording head may be detached from the ink jet recording apparatus and stored in a storage container provided with an ink drying prevention device.

[0003] As such an ink drying prevention device,
Some use a so-called sealing cap. In this closed cap method, an elastic cap opened toward the ink ejection surface is prepared, and the peripheral portion of the cap is pressed against the ink ejection surface so as to surround the periphery of the ink ejection port. Attach to the inkjet recording head. This creates a sealed space between the ink ejection surface and the cap, and prevents drying of the ink from the ink ejection ports.

However, in the closed cap method, air may be pushed into the nozzles when the cap is pressed against the ink ejection surface or due to environmental changes (temperature rise or pressure drop) after the cap is mounted on the ink jet recording head. . In order to discharge this air, the ink jet recording head
For example, a maintenance operation such as a vacuum operation needs to be performed. However, a large amount of time and cost are required for the maintenance depending on the amount of pushed air.

In order to avoid such inconveniences, there has been proposed a configuration in which a cap is provided with an air communication hole. That is, by providing a communication hole in the cap and communicating between the inside of the cap and the outside (atmosphere), an excessive increase in pressure inside the cap is mitigated, and pushing of air into the nozzle is avoided.

However, even when the ink drying prevention device arrives at the ink jet recording head, the air communication hole allows the inside and the outside of the cap to communicate with each other. It is difficult to prevent the ink from evaporating and drying the ink for a long period of time.

On the other hand, there has been proposed an ink drying prevention device using a close contact cap. In the contact cap method, a cap formed to be deformable with an elastic member
The ink ejection port is brought into close contact with the ink ejection surface so as to cover the ink ejection port, and the ink ejection port is shielded from the air.

However, even in this close contact cap method, air is present near the nozzle on the ink ejection surface, inside the nozzle, and between the cap and the ink ejection surface. In some cases, air may be pushed into the nozzle. In particular, the cap used in the contact cap method can be deformed as described above to improve the adhesion to the ink ejection surface, etc. It is more likely that air will be pushed into the nozzle.

[0009]

SUMMARY OF THE INVENTION In consideration of the above facts, the present invention can reliably prevent the ink from drying over a long period of time by bringing the cap member into close contact with the ink discharge surface, and can also provide a defective ink supply due to air intrusion. , An ink drying prevention device that does not push air into the nozzles, an ink jet recording head storage container to which the ink drying prevention device is applied, an ink jet recording device, and this ink An object of the present invention is to provide an ink drying prevention method using a drying prevention device.

[0010]

According to the first aspect of the present invention, there is provided an ink drying prevention device for preventing drying of ink inside an ink jet recording head for discharging ink droplets from ink discharging ports, A convex meniscus forming means for forming a convex meniscus of the ink at an outlet; and an ink ejection port which is in close contact with an ink ejection surface of an ink jet recording head in a state where the convex meniscus is formed at the ink ejection port by the convex meniscus forming means. And a cap member for sealing.

Incidentally, the “convex meniscus” in the present invention means that the ink in the nozzle of the ink jet recording head is
The meniscus is formed so as to protrude outward from the ink discharge port, and the convex meniscus is exposed from the ink discharge surface.

In the first aspect of the present invention, the cap member is in close contact with the ink discharge surface to seal the ink discharge port. Thereby, drying of the ink from the ink discharge ports is prevented, and clogging of the nozzles can be prevented even when the inkjet recording head is not used for a long period of time.

In addition, a convex meniscus is formed in the ink discharge port by a convex meniscus forming means, and in this state, the cap member is in close contact with the ink discharge surface. Since the convex meniscus is formed, air in the nozzles of the ink jet recording head is discharged to the outside, so that the cap member adheres to the ink discharge surface in a state in which no air exists in the nozzles or near the nozzles on the ink discharge surface. Will be done.
For this reason, it is possible to prevent the ink from drying due to the air present in the nozzles, to prevent ink supply defects from occurring, and to reduce the maintenance load.

In the ink drying prevention device according to the first aspect, the ink jet recording head capable of preventing the drying of the ink is not limited. For example, as described in the second aspect, the ink jet recording head stores the ink. An ink chamber may be provided, and the ink may be prevented from drying in correspondence with the ink jet recording head having the ink chamber.

The ink chamber according to the second aspect of the present invention is not particularly limited and is widely included as long as it stores the ink ejected from the ink jet recording head. In general, some inkjet recording heads include an ink chamber (common ink chamber) common to a plurality of nozzles, and an ink tank (or sub ink tank) in which ink to be supplied to the common ink chamber is stored in advance. Some have a structure. In the case of an ink jet recording head having such a structure, the “ink chamber” according to claim 2 includes, among these common ink chamber and ink tank,
This concept broadly includes a space that communicates with the nozzles and holds the stored ink.

In the case of the ink drying prevention device according to the second aspect, as the convex meniscus forming means, the convex meniscus forming means increases the internal pressure of the ink chamber. And the convex meniscus forming means may include a volume reducing means for reducing the volume of the ink chamber. Of course, a configuration including both of these may be used. Further, as described in claim 5, the convex meniscus forming means may be configured to include a piezoelectric element provided in the ink jet recording head. In the case of this configuration, in the ink jet recording head, Since the piezoelectric element provided in advance for ejecting ink droplets can be used as the convex meniscus forming means in the present invention, the components of the ink jet recording head and the components of the ink drying prevention device can be shared, and the number of parts is reduced. Become.

In the invention described in claim 6, a negative pressure generating means for setting the inside of the ink chamber to a constant negative pressure state, the negative pressure state in the ink chamber, and a pressure closer to the atmospheric pressure than the negative pressure state. Switching means for switching between a substantially atmospheric pressure state.

The "substantially atmospheric pressure state" here is closer to atmospheric pressure than the negative pressure state of the ink chamber (having a constant negative pressure) generated by the negative pressure generating means, but is completely atmospheric pressure. This includes both the state where the pressure is not at atmospheric pressure and the state where the pressure is completely at atmospheric pressure. By switching between the negative pressure state and the substantially atmospheric pressure state by the switching means, it is possible to prevent inadvertent leakage of ink from the ink ejection surface. For example, as described in claim 7, the switching means allows the ink chamber to be switched to the substantially atmospheric pressure state after closing the ink discharge port with the cap member, so that the cap member is It is possible to prevent the ink from leaking before the ink comes into close contact with the ink ejection surface. Further, as described in claim 8, the switching means allows the ink chamber to be switched to the negative pressure state when the cap member is separated from the ink ejection surface, so that the cap member can be switched. It is possible to prevent leakage of ink when the ink is separated from the ink ejection surface.

The negative pressure generating means may be newly provided in the ink drying prevention device. For example, as set forth in claim 9, the negative pressure generating means may be provided in the ink absorbing device provided in the ink chamber. Sex member. In this configuration, the liquid-absorbing member provided in advance in the ink chamber of the ink jet recording head can be used as the negative pressure generating means of the present invention, so that the number of parts is smaller than the configuration in which the negative pressure generating means is newly provided. Less.

According to a tenth aspect of the present invention, in the ninth aspect of the present invention, the switching means includes an opening / closing member for opening and closing a communication hole for communicating the inside of the ink chamber of the ink jet recording head with the outside. It is characterized by having been done.

As described above, the ink chamber can be switched between the negative pressure state and the substantially atmospheric pressure state with a simple configuration in which the communication hole is opened and closed by the opening and closing member.

According to the eleventh aspect of the present invention, in the first aspect,
An ink drying prevention device according to claim 10 is provided.

Therefore, by storing the ink jet recording head in this ink jet recording head storage container,
Drying of the ink from the inside of the ink jet recording head can be prevented by the ink drying prevention device, and clogging of the ink ejection ports due to drying and solidification of the ink can be reduced.

Further, since this ink jet recording head storage container is provided with the ink drying prevention device according to any one of the first to tenth aspects, a convex meniscus is formed at the ink discharge port by the convex meniscus forming means. In this state, the cap member comes into close contact with the ink ejection surface. This allows the cap member to be in close contact with the ink ejection port in a state where no air exists in the nozzles of the inkjet recording head, so that drying of the ink due to air in the nozzles can be prevented.

In the twelfth aspect of the present invention,
An ink drying prevention device according to claim 9 is provided.

This ink jet recording apparatus is characterized in that
Since the ink drying prevention device according to any one of claims 9 to 9 is provided, the ink drying prevention device is provided.
Drying of the ink inside the ink jet recording head can be reliably prevented.

In a state in which the convex meniscus is formed at the ink discharge port by the convex meniscus forming means, the cap member comes into close contact with the ink discharge surface. This allows the cap member to be in close contact with the ink ejection port in a state where no air exists in the nozzles of the inkjet recording head, so that drying of the ink due to the air in the nozzles can be prevented. With a simple configuration, it is possible to prevent air from being pushed into the ink jet recording head.

According to the thirteenth aspect of the present invention,
An ink drying prevention method for preventing drying of ink inside an ink jet recording head using the ink drying prevention device according to any one of claims 10 to 14, wherein the convex meniscus forming means forms the ink at the ink discharge port. A convex meniscus forming step of forming the convex meniscus, and sealing the ink discharge port by closely contacting the cap member with the ink discharge surface in a state where the convex meniscus is formed in the ink discharge port by the convex meniscus forming step. And a capping step.

According to this ink drying prevention method, in the convex meniscus forming step, a convex meniscus is formed at the ink discharge port by the convex meniscus forming means. Then, in this state, in the capping step, the cap member is brought into close contact with the ink ejection surface to seal the ink ejection port. The formation of the convex meniscus discharges the air in the nozzles of the ink jet recording head to the outside, so that the cap member comes into close contact with the ink ejection surface in a state where no air exists in the nozzles. Therefore, it is possible to prevent the ink from drying due to the air present in the nozzle.

When the cap member is in close contact with the ink discharge surface and seals the ink discharge port, drying of the ink from the ink discharge port is prevented, and the ink jet recording head is not used for a long period of time. However, clogging of the nozzle can be prevented.

According to a fourteenth aspect of the present invention, there is provided an ink drying prevention method for preventing drying of ink inside an ink jet recording head using the ink drying prevention device according to the seventh aspect, wherein the cap member is After the ink discharge port is closed, the switching means brings the ink chamber into the substantially atmospheric pressure state.

After the ink discharge port is closed by the capping member, the ink chamber is brought into a substantially atmospheric pressure state by the switching means, so that it is possible to prevent ink leakage before the cap member comes into close contact with the ink discharge surface.

When the cap member is in close contact with the ink discharge surface and seals the ink discharge port, drying of the ink from the ink discharge port is prevented, and even when the ink jet recording head is not used for a long time, etc. , Nozzle clogging can be prevented.

A convex meniscus is formed at the ink discharge port by a convex meniscus forming means. In this state, the cap member is in close contact with the ink discharge surface, so that no air exists in the nozzle of the ink jet recording head. In this state, the cap member is in close contact with the ink discharge port, and it is possible to prevent the ink from drying due to the air in the nozzle.

According to a fifteenth aspect of the present invention, there is provided an ink drying prevention method for preventing drying of ink inside an ink jet recording head using the ink drying prevention device according to the eighth aspect, wherein the switching means includes After the negative pressure is applied to the ink chamber, the capping member is separated from the ink ejection surface.

Since the cap member is in close contact with the ink discharge surface to seal the ink discharge port, it is possible to prevent the ink from drying out from the ink discharge port, and even if the ink jet recording head is not used for a long period of time, Nozzle clogging can be prevented.

Further, a convex meniscus is formed at the ink discharge port by a convex meniscus forming means. In this state, the cap member is in close contact with the ink discharge surface, so that no air exists in the nozzle of the ink jet recording head. In this state, the cap member is in close contact with the ink discharge port, and it is possible to prevent the ink from drying due to the air in the nozzle.

When the capping is eliminated, the capping member is separated from the ink discharge surface after the ink chamber is set to the negative pressure state by the switching means, so that the leakage of the ink when the cap member is separated from the ink discharge surface is prevented. it can.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Ink Drying Prevention Device] (Basic Configuration) FIG. 1 shows a basic configuration of an ink drying prevention device 102 of the present invention. The ink drying prevention device 102 has a cap member 103 that is in close contact with the ink ejection surface 14 of the ink jet recording head 12 and seals the ink ejection port 16. Cap member 1
03 is, for example, a box-shaped holding member 10 that is open on one side.
6, there may be mentioned a configuration having a block-shaped contact member 104 arranged so that one surface is exposed from the open portion. In short, if the ink discharge port 16 can be sealed in close contact with the ink discharge surface 14 , Cap member 1
The configuration of 03 is not particularly limited. For example, as in each of the embodiments described below, the contact member 104 may be formed in a film shape and bridged so as to cover an open portion of the holding member 106, and further, the elastic member 105 may be disposed inside the holding member 106. In the configuration having the elastic member 105, the elastic member 1
The adhesive force of the ink ejection port 16 to the ink ejection surface 14 can be enhanced by the elastic force of 05. Of course, if sufficient adhesion can be ensured by the elasticity of the adhesion member 104 itself, the elastic member 105 is not necessarily provided.

Generally, a plurality of ink discharge ports 16 are formed on the ink discharge surface 14 of the ink jet recording head 12, and these plural ink discharge ports 16 can be simultaneously sealed by the cap member 103.

Further, the ink drying prevention device 102 of the present invention
Then, while supporting the cap member 103, the separated position (see FIG. 1A or 1B) and the close position (FIG. 1C)
Support member 108 which is relatively movable between
have. Here, the “separated position” is a position where the cap member 103 is separated from the ink ejection surface 14 and does not seal the ink ejection port 16, and the “close contact position” is a position where the cap member 103 adheres to the ink ejection surface 14. This refers to the position where the ink ejection port 16 is sealed. Therefore, the specific configuration is not limited as long as it can move between the “separated position” and the “close contact position”. Further, the cap member 103 and the ink ejection surface 14 (ink jet recording head 12) may be relatively moved between the “separated position” and the “close contact position”. In addition, the configuration in which only the inkjet recording head 12 moves, the cap member 1
03 and the inkjet recording head 12 may move.

The specific structure of the support member 108 is not particularly limited, and a general elevating mechanism can be employed. For example, as shown in FIG. 1, while configuring an “X” -shaped link mechanism 110 configured by two links,
It is also possible to adopt a configuration in which a support table 109 is attached to the link mechanism 110. The cap member 103 can be moved toward or away from the ink ejection surface 14 by raising and lowering the support table 109 using a drive device (not shown) (for example, a motor or a solenoid).
In the case of the support member 108 having such a configuration, the support base 109
Alternatively, the contact member 104 may be directly attached (or by sandwiching the elastic member 105 between the support table 109) and the holding member 106 may be omitted.

Further, the ink drying prevention device 10 of the present invention
2, at least the contact member 104 is
Before contact with the ink, the convex meniscus 22
Is provided.
As shown in FIG. 1B, before the contact member 104 comes into close contact with the ink ejection surface 14 and seals the ink ejection port 16,
The convex meniscus forming means 107 is driven, and the convex meniscus 22 is formed at the ink ejection port 16. The convex meniscus 22 is a meniscus having a structure that is convex from the ink chamber 20 toward the ink ejection port 16 and is exposed from the ink ejection surface 14 (in contrast, the ink meniscus 22 has The meniscus concave toward the outlet 16 is hereinafter referred to as a “concave meniscus”.
The concave meniscus is inevitably formed on the ink ejection surface 14 due to its structure.
Is a meniscus that is not exposed from the surface).

By forming such a convex meniscus 22, the air in the nozzle 18 is pushed to the outside, so that the contact member 104 comes into close contact with the ink ejection surface 14 in a state where no air exists in the nozzle 18, and Seal 16 If the ink ejection port 16 is sealed while air is present in the nozzle 18, the ink may evaporate into the air, causing nozzle clogging. The ink drying prevention device 102 of the first embodiment does not have such a disadvantage, and can more reliably prevent the evaporation of the ink in the nozzle 18. In particular, the contact member 104
Is in close contact with the ink ejection surface 14, the contact member 10
There is a possibility that air exists between the nozzle 4 and the ink ejection surface 14 and this air is pushed into the nozzle 18.
In the ink drying prevention device of the present invention, the air in the vicinity of the ink ejection port 16 is also excluded by the convex meniscus 22, so that such pushing of the air can be prevented.

In addition, as shown in FIG. 1C, in a state where the contact member 104 is in close contact with the ink ejection surface 14 and the ink ejection port 16 is sealed, the ink forming the convex meniscus 22 is removed from the ink ejection surface. The ink spreads around the ink ejection port 16 at the boundary between the contact member 14 and the contact member 104. Then, as a result, as shown in detail in FIG. 2, the liquid spread to the periphery further ensures the close contact, so that a so-called liquid seal 24 is formed. The ink inside the close contact nozzle 18 is not communicated with the outside by the liquid seal 24. Can be more effectively prevented from entering. of course,
The adhesion of the contact member 104 to the ink ejection surface 14,
Depending on the type of ink, even if such a liquid seal 24 is not formed, drying of the ink and intrusion of air into the nozzle 18 may be prevented in some cases. The configuration need not be such that it is formed.

The convex meniscus 22 is more likely to evaporate to the outside air and break down the meniscus due to the outside air flow than the concave meniscus, and the meniscus breakage causes leakage of ink and entry of air into the nozzle 18. Therefore, the time during which the convex meniscus 22 is formed is preferably as short as possible. Therefore, the timing of forming the convex meniscus 22 should be as late as possible as long as it is before the contact member 104 is in close contact with the ink ejection surface 14 so that the duration after the convex meniscus 22 is formed can be short. This is preferable because the above-mentioned disadvantages can be reduced. However, depending on the type of the ink, the surrounding environment, the atmosphere, and the like, there are cases where evaporation of the ink and destruction of the meniscus hardly cause a problem. In this case, the timing of forming the meniscus can be set relatively wide.

FIG. 1 shows a convex meniscus forming means 10.
7, a side wall 20S of the ink chamber 20 is pressed and displaced into the ink chamber 20, and the volume of the ink chamber 20 is reduced to increase the internal pressure. The specific configuration of 107 is not limited to this. For example, the convex meniscus 22 may be formed by feeding a fluid such as air using a pump or a syringe, etc., without reducing the volume in the ink chamber 20. In this case, the convex meniscus 22
When the pressure is high enough to form the nozzle, no inconvenience occurs because the delivered air cannot reach the inside of the nozzle 18.

In the configuration in which the convex meniscus 22 is formed at the ink ejection port 16 by increasing the internal pressure of the ink chamber 20, the magnitude of the pressure to be increased depends on the number of nozzles of the ink jet recording head 12, the diameter of the ink ejection port 16, the ink ejection port 16, and the like. It depends on the surface energy of the surface 14, the surface tension of the ink, etc.
The internal pressure to be increased can be adjusted by adjusting the volume reduction so as to be a pressure capable of forming a stable convex meniscus 22.

In order to obtain a stable convex meniscus 22, if the pressure to be increased in the present invention is ΔP, it is sufficient that the negative pressure of the ink chamber <ΔP <the maximum holding force due to the capillary force of the convex meniscus. Preferably, the negative pressure of the ink chamber × 2 ≦ ΔP ≦ the maximum holding force due to the capillary force of the convex meniscus × 0.5 (1).

As an example, the diameter of the nozzle 18 (generally, approximately equal to the diameter of the ink discharge port 16) is 10 μm.
m, and the ink surface tension (γ) is γ = 40 mN / m, the maximum holding force due to the capillary force of the convex meniscus 22 is about 1.6 × 10 ⁴ Pa, and the negative pressure of the ink chamber 20 is at most 9. Since it is about 8 × 10 ² Pa, a preferable range of the value is 2.0 × 10 ³ Pa ≦ ΔP ≦ 8.0 × 10 ³ Pa (2).

If the temperature is constant, P · V = constant.
The volume V ′ of the ink chamber 20 after the volume reduction is set to be 0.92 V ≦ V ′ ≦ 0.98 V with respect to the volume V of the ink chamber 20 before the volume reduction. 2% to 8% volume
It can be seen that the design should be such that compression is possible.

Incidentally, an ink bridge may be formed between the convex meniscus 22 and the close contact member 104. In this case, for example, ΔP may exceed the above-mentioned range. That is, immediately before the contact member 104 is in close contact with the ink ejection surface 14, the internal pressure of the ink chamber 20 is adjusted so as to be higher than the internal pressure at which the convex meniscus 22 is formed and lower than the pressure at which the ink is separated as ink droplets. Then, the ink forming the convex meniscus 22 adheres so as to be bridged between the contact member 104 and the ink ejection surface 14, and an ink bridge is formed therebetween.
Thereafter, the ink ejection port 16 can be sealed by bringing the adhesion member 104 into close contact with the ink ejection surface 14. Further, the liquid seal 24 can be formed in a wider area by the ink that has been bridged, and the adhesion can be further improved.

In many cases, the ink jet recording head 12 is provided with an air communication hole 26 in the ink chamber 20 (or ink tank). By communicating the inside and the outside of the ink chamber 20 with the atmosphere communication hole 26, a sudden pressure fluctuation in the ink chamber 20 is reduced, and the careless leakage and the like of the ink are prevented. When such an air communication hole 26 is provided, the ink chamber 2
Even if the inside of 0 is pressurized, the pressure may escape from the atmosphere communication hole 26 when the pressure rises. Therefore, at least from the start of the pressure rise to the end of the capping, the atmosphere communication hole 26
The cap operation time is shortened (for example, the separation position of the contact member 104 is set close to the contact position) so that a means for closing the contact member is provided or the capping can be completed before the pressure escapes from the atmosphere communication hole 26. It is preferable to design or increase the flow path resistance of the atmosphere communication hole 26 to delay the time for the pressure to escape.

In the present invention, the contact member 104 has a gas barrier property that does not allow air to pass for a long time during capping.
It is preferable that the material has elasticity or viscosity that can follow the shape of the above. Examples of such elastic materials include various rubbers and various elastomers such as butyl rubber, polyurethane rubber, acrylic rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, and silicone rubber. In addition, as a viscous material, a gel-like polymer material, gas or liquid,
Alternatively, a material having a structure in which a granular material is enclosed can be used.

Hereinafter, each embodiment of the ink drying prevention device of the present invention will be described. In the following embodiments,
The same components, members, and the like are denoted by the same reference numerals, and redundant description will be omitted as appropriate.

(First Embodiment) FIG. 3 shows a first embodiment of the present invention.
The ink drying prevention device 112 of the embodiment is shown.

The ink drying prevention device 112 of the first embodiment
Then, as the convex meniscus forming means 107, the ink chamber 2
A pressing member 117 for pressing the 0 side wall 20S is arranged. In addition, the inkjet recording head 12 is also configured so that at least a part of the side wall 20S of the ink chamber 20 is deformed by being pressed.
In the example shown in FIG. 3, a bent portion is formed substantially at the center of the side wall 20S in the vertical direction, and the side wall 20S is bent at the bent portion.
The ink chamber 20 is deformed into the ink chamber 20, but is not limited thereto. For example, the side wall 20S may be configured such that all or a part of the side wall 20S is curved.

The amount of deformation of the side wall 20S depends on the ink chamber 2
0 so that the internal volume of 0 falls within the range satisfying the above equation (3).
It is limited to a predetermined range in advance. Therefore, the required convex meniscus 22 is not formed or the convex meniscus 22 is not held.

The method for keeping the deformation amount of the side wall 20S within the predetermined range as described above is not particularly limited. For example, the ink jet recording head 12 may be provided with a restricting member for restricting the deformation of the side wall 20S. Alternatively, the amount of movement of the pressing member 117 may be limited so that the amount of deformation of the side wall 20S may be within a predetermined range.

The pressing of the side wall 20S by the pressing member 117 needs to be performed at least before the close contact of the contact member 104 to the ink ejection surface 14. When the pressing member 117 is configured to be operable by the user, the user first manually moves the pressing member 117 to press the side wall 20S to form the convex meniscus 22 (see FIG. 3B). Then, the contact member 104 is moved to the ink ejection surface 1.
4 to seal the ink discharge port 16 (see FIG. 3C). Also, as described below,
An interlocking mechanism may be provided so that the side wall 20S can be pressed in conjunction with the close contact of the contact member 104 with the ink ejection surface 14.

(Second Embodiment) FIG. 4 shows a second embodiment of the present invention.
The ink drying prevention device 122 of the embodiment is shown.

The ink drying prevention device 122 of the second embodiment
In the embodiment, the side wall 20S of the ink chamber 20 of the ink jet recording head 12 is formed of an extension member that extends under a certain condition. Under a certain condition, the side wall 20S is deformed (curved in this example) as shown by a two-dot chain line in FIG. 4, and the inner volume of the ink chamber 20 is reduced within a range satisfying the above equation (3). As a result, the convex meniscus 22 is
(See FIG. 1B).

As the extension member constituting the side wall 20S,
There is no particular limitation as long as it can be extended under certain conditions, and members or means for generating the conditions for elongation are appropriately arranged in accordance with the configuration of the extended member. For example, the side wall 20S is formed of a member (a so-called shape memory alloy) that expands or expands due to thermal stimulation or the like, and a heating unit that heats the side wall 20S (a heater 127 is disposed as an example of a heating unit in FIG. 4). ) May be provided. In addition, for example, a structure in which members having different coefficients of thermal expansion such as bimetals are bonded to each other and may be bent by heating may be used.

(Third Embodiment) FIG. 5 shows a third embodiment of the present invention.
The ink drying prevention device 132 of the embodiment is shown.

An ink drying prevention device 132 according to the third embodiment
In the embodiment, a moving wall 28 is provided in the ink chamber 20.
The moving wall 28 is movable in the left-right direction in FIG. 5, and ink is stored only in a portion on the left side of the moving wall 28. In the third embodiment, the side wall 20
Is different from the first and second embodiments in that it does not deform or move.

The moving wall 28 is arranged in parallel with the side wall 20S, and is attached to the ink chamber 20 by a mounting member (not shown) so as to come in contact with and separate from the side wall 20S while maintaining the parallel state.

On the opposing surfaces of the side wall 20S and the moving wall 28,
An electrode 30 is attached as moving means for moving the moving wall 28. The electrode 30 is connected to a control circuit (not shown), and switches ON / OFF of an electric signal from the control circuit.
By turning OFF, an electric attractive force or a repulsive force acts between the electrodes 30 to move the moving wall 28. Further, the moving amount of the moving wall 28 is restricted to a predetermined range by a restricting member (not shown) provided in the ink chamber 20. Therefore, when the moving wall 28 moves to the left in FIG.
Since the internal volume of the ink chamber 20 in the ink chamber 20 is reduced, a convex meniscus 22 (see FIG. 1B) is formed at the ink ejection port 16.

(Fourth Embodiment) FIG. 6 shows a fourth embodiment of the present invention.
The ink drying prevention device 142 of the embodiment is shown.

The ink drying prevention device 142 of the fourth embodiment
In the figure, the support 109 is extended to the side, and the lower end of the link 144 is pivotally supported at the tip. Further, the ink drying prevention device 142 is provided with a peripheral wall 142S, and a pin 146 protrudes from the peripheral wall 142S. Pin 14
6 is a long hole 1 formed near the upper end of the link 144.
44H. Thus, an interlocking mechanism 147 also serving as the convex meniscus forming means 107 is configured.

The position, length, and slot 144H of the link 144
6A, when the cap member 103 is at the most lowered position as shown in FIG. 6A, the upper end of the link 144 does not press the side wall 20S. As shown in FIG. 6B, the cap member 1
As the link 03 rises, the link 144 also inclines while rising, and presses the side wall 20 </ b> S to form the convex meniscus 22 before the contact member 104 comes into close contact with the ink ejection surface 14 so as to form the convex meniscus 22. Have been.

Therefore, in the ink drying prevention device 142 of the fourth embodiment, the convex meniscus 22 can be formed in conjunction with the operation of raising the cap member 103 (the operation of approaching the ink ejection surface 14). At this time, the position and length of the link 144, the position and length of the long hole 144H,
Since the positions and the like of the pins 146 are set as described above, after the convex meniscus 22 is surely formed in the ink ejection port 16, as shown in FIG. And the ink ejection port 16 is sealed.

The interlocking mechanism 147 only needs to be able to form the convex meniscus 22 in conjunction with the approaching operation of the close contact member 104 and the ink ejection surface 14 as described above. There may be. For example,
In the ink drying prevention device 122 of the second embodiment, the heating means (heater 127) is activated by raising the cap member 103.
And so on. Similarly, the ink drying prevention device 132 of the third embodiment may be configured to control an electric signal to the electrode 30 as the cap member 103 moves up. However, as compared with such an electrical connection, a mechanical connection using the link 144 and the like as in the second embodiment is preferable because the configuration is easy and the cost is low.

As described above, the timing of forming the convex meniscus 22 is preferably immediately before the contact member 104 is brought into close contact with the ink ejection surface 14 according to the type of ink, the surrounding environment, the atmosphere, and the like. There is. Therefore, the configuration in which the formation of the convex meniscus 22 is performed by the mechanical interlocking mechanism 147 as in the present embodiment is preferable because such timing control becomes easy.

(Fifth Embodiment) FIG. 7 shows a fifth embodiment of the present invention.
The ink drying prevention device 152 of the embodiment is shown.

An ink drying prevention device 152 according to the fifth embodiment
Has an interlocking mechanism 147 having the same configuration as that of the fourth embodiment.

In the fifth embodiment, an ink jet recording head having a negative pressure generating means 32 is used. The negative pressure generating means 32 is connected to the ink chamber 20.
This is a means for preventing inadvertent leakage of ink from the ink ejection port 16 by generating a negative pressure in the inside. Normally,
The negative pressure generated by the negative pressure generating means 32 balances the holding force of the ink meniscus at the ink ejection port 16 (which may be the convex meniscus 22 or the concave meniscus as in the present invention), and is generally used. It is installed in the ink chamber (or inside the ink tank) of a simple inkjet recording apparatus.

Further, the ink jet recording head according to the fifth embodiment has a negative pressure canceling means 34 for canceling the negative pressure by the negative pressure generating means 32 and setting the pressure to a substantially atmospheric pressure state. Therefore, in the state where the negative pressure is not canceled by the negative pressure canceling means 34, the negative pressure generating means 3
2, the pressure in the ink chamber 20 becomes negative.

In this embodiment, as can be seen from FIG.
A partition 36 is provided in the inkjet recording head 12, and one area (the left area in the drawing) separated by the partition 36 is the ink chamber 20, and the other area is a negative pressure provided with a negative pressure generating unit. It is a generation area. These two regions communicate with each other through a communication portion 38 formed in the partition 36.

In this embodiment, the negative pressure generating means 32
Uses a porous body 40 having a large number of pores inside. That is, the ink chamber 2 is provided in the pores of the porous body 40.
0 is impregnated with the ink chamber 20
The inside becomes negative pressure. When such a porous body 40 is used as the negative pressure generating means 32, an appropriate hole diameter, surface tension, insertion amount into the ink chamber, shape, and dimensions are optimized so as to oppose the holding force of the ink meniscus. Become

As the material of the porous body 40,
Conventionally known materials can be used as long as they have the ability to hold the ink even under the own weight of the liquid (ink) and slight vibration. For example, a cotton-like body in which fibers are meshed into a net, a porous body having communication holes, and the like can be given. A sponge such as a polyurethane foam whose ink holding power and negative pressure generation are easily adjusted is preferable. In particular, a foam is preferable because it can be adjusted to a desired porosity during foam production.

The negative pressure canceling means 34 of this embodiment has an opening / closing member 42 for opening / closing the atmosphere communication hole 26 with respect to the atmosphere communication hole 26 communicating the inside and the outside of the ink chamber 20. The opening / closing member 42 is constantly urged to the left side in the drawing by an urging member (not shown), and closes the atmosphere communication hole 26 in a normal state.

On the other hand, the ink drying prevention device 152 is provided with a negative pressure switching interlocking mechanism 154 in addition to the interlocking mechanism 147 similar to the third embodiment. The negative pressure switching interlocking mechanism 154 is constituted by an interlocking plate 156 erected upward from the support table 109. An inclined surface 156S is formed at the upper end of the interlocking plate 156.
One end of the opening / closing member 42 is in contact with S. When the cap member 103 moves up, the interlocking plate 156 also moves up,
The inclined surface 156S pushes the opening / closing member 42 to move it to the right in the drawing. When the opening / closing member 42 moves by a predetermined amount, the atmosphere communication hole 26 and the opening hole of the opening / closing member 42 match, and the ink chamber 20 is opened to the atmospheric pressure. In the atmospheric pressure release state, even if a negative pressure is generated by the negative pressure generating means 32, the negative pressure is canceled by the atmospheric pressure and the ink chamber 2 is released.
No negative pressure occurs in 0.

The canceling means is not limited to the structure in which the atmosphere communication hole 26 is opened and closed by the opening and closing member 42 as described above. In short, the canceling means reduces or eliminates the negative pressure corresponding to the structure of the negative pressure generating means 32. What is necessary is just to set the inside of the ink chamber 20 to “substantially atmospheric pressure state”. For example, the communication part 38 formed in the partition 36 may be closed so that the negative pressure of the negative pressure generating means 32 does not act on the ink chamber 20. Alternatively, in a configuration in which the porous body 40 is used as the negative pressure generating means 32, the porous body 40 is mechanically compressed to substantially eliminate pores, or conversely, the porous body 40 is mechanically compressed. It can be configured to cancel the negative pressure by expanding the pores by expanding and eliminating the capillary force.

The negative pressure switching interlocking mechanism 154 is not necessarily required.
May not be provided. In this case, at a predetermined timing (for example, at the time of capping, etc.), a notification means such as a lamp or a sound notifies the switching timing,
The user may manually switch.

The ink drying prevention device 15 having such a configuration
2, at least during capping, that is, when the contact member 104 is in close contact with the ink ejection surface 14 and the ink ejection port 1
With the seal 6 sealed, the negative pressure in the ink chamber 20 can be canceled to bring the ink chamber 20 into a substantially atmospheric pressure state. This allows the nozzle 1 to move from the ink ejection port 16 during capping.
Since no force (driving force) for drawing air into the nozzle 8 is generated, the negative pressure in the nozzle 18 is also eliminated, and the intrusion of air into the nozzle 18 can be more reliably prevented. For example, when capping is performed in the presence of a foreign substance between the contact member 104 and the ink ejection surface 14, the foreign substance slightly reduces the adhesion, and air easily enters the nozzle 18. However, even in such a case, it is possible to reliably prevent air from entering the nozzle 18.

The timing for releasing the inside of the ink chamber 20 to the atmospheric pressure is after the convex meniscus 22 is formed in the ink discharge port 16 by the convex meniscus forming means 107 and the contact member 104 is brought into close contact with the ink discharge surface 14. It is preferable that In other words, with such timing, the inside of the ink chamber 20 is kept at a negative pressure even during capping, so that ink leakage from the ink ejection port 16 can be prevented.

Further, it is preferable that the pressure in the ink chamber 20 is again reduced to a negative pressure before the close contact member 104 is separated from the ink ejection surface 14. In other words, since the inside of the ink chamber 20 is already at a negative pressure when the contact member 104 is separated from the ink ejection surface 14, it is possible to prevent the ink in the nozzles 18 from being dragged by the contact member 104 and leaking out. .

(Sixth Embodiment) FIG. 8 shows a seventh embodiment of the present invention.
The ink drying prevention device 162 of the embodiment is shown.

In the sixth embodiment, the discharge means of the ink jet recording head is configured to also serve as the convex meniscus forming means 107 in the present invention.

The ejection means 44 is configured, for example, such that the ink jet recording head 12 is an ink jet recording device 182 (FIG. 10).
This is means for applying ejection energy to the ink in the nozzles 18 so that the ink droplets corresponding to the image information are ejected in a state where the ink droplets are incorporated in the inside of the nozzle 18. Ink drying prevention device 1
Reference numeral 62 denotes a drive unit (not shown) for driving the discharge unit 44 so that the convex meniscus 22 is formed at the ink discharge port 16. When the ink drying prevention device 162 is incorporated in the ink jet recording device 182, a control device for controlling the driving of the ejection device 44 in normal image recording can be used as the driving device.

In the sixth embodiment, when no image is recorded, as shown in FIG.
Is not driven, and no convex meniscus 22 is formed. At the time of capping, by driving the ejection means 44, first, as shown in FIG. 8B, the ink in the nozzles 18 is pressurized to such an extent that ink droplets are not ejected, and the convex meniscus 22 is formed. Then, the convex meniscus state is maintained until the contact member 104 comes into close contact with the ink ejection surface 14. Then, as shown in FIG. 8C, the convex meniscus 2
In the state in which the ink droplets 2 are formed, the contact member 104 is brought into close contact with the ink ejection surface 14 to seal the ink ejection ports 16.

As the discharge means 44 of the present embodiment, for example, a heating element, a piezoelectric element (piezo-electric vibrator) and the like are widely used. And the like using the above energy can be applied as the convex meniscus forming means 107 of the present invention.
In particular, the piezoelectric element is preferable because the degree of pressurization of the ink in the nozzle 18 can be adjusted and the pressurized state can be kept constant.

The material of the piezoelectric element is ZnO, BaTi
Examples include O ₃ (barium titanate), PbTiO ₃ (lead titanate), and a multilayer piezoelectric element of a piezoelectric sintered body of a solid solution of PbTiO ₃ and PbZrO ₃ (lead zirconate).

In an ink jet recording head in which a piezoelectric element is used as the discharging means 44, when a voltage similar to that of a normal ink droplet discharging operation is applied to the piezoelectric element, an ink droplet is discharged, and the above-described formula is statically applied. It is difficult to give a displacement satisfying the condition shown in (3). In this case, the waveform parameters to be applied may be changed and applied, for example, by lowering the voltage value or making the slope of the voltage change gentler, so that the convex meniscus 22 is formed.

As described above, in the ink drying prevention apparatus of the present invention, the ink discharge port 16 is sealed by bringing the contact member 104 into close contact with the ink discharge surface 14 with the convex meniscus 22 in the ink discharge port 16 as described above. So nozzle 1
8 can be capped without air.

In the ink jet recording head according to each embodiment, various characteristics generally required for the wall member constituting the ink chamber 20 include (1) no influence on the ink (2) gas barrier property (3) It is a polymer compound that does not cause swelling or deformation by the ink. (4) It is excellent in weather resistance and environmental resistance.

Suitable materials satisfying all of these conditions include, specifically, fluorine-based rubber, PVC (polyvinyl chloride), PVA (polyvinyl alcohol), and PVdC.
(Polyvinylidene chloride), PE (polyethylene), PP
(Polypropylene), polyolefin, EVA (ethylene-vinyl acetate copolymer), polybutene, EPDM, EP
R / EPT, butyl chloride rubber, polyurethane, acrylic rubber, silicone rubber, BR (polybutadiene rubber),
NBR (acrylonitrile butadiene rubber), SBR
(Styrene butadiene rubber), IR (isoprene rubber), IIR (isoprene isobutylene rubber), CR
(Chloroprene rubber), chlorosulfonated PE, polysulfide rubber and the like.

Also, a material having desired characteristics may be laminated as a multilayer. In that case, it is possible to configure so as to have the characteristics required for each side wall 20S, moving wall 28, etc., corresponding to each embodiment. For example, since the side wall 20S of the first embodiment is preferably a soft material that is relatively easily deformable, it is easy to deform by appropriately selecting and laminating the above-described materials.

Further, for example, in the moving wall 28 of the third embodiment, since the inner surface of the ink chamber 20 and the moving wall 28 slide, a combination of materials having excellent slidability reduces the sliding resistance. The moving wall 28 can be used.

As other examples, as the innermost layer, a material having excellent ink resistance and good wettability is used, the coefficient of friction with the member for applying pressure is low, and the deformation of the side wall 20S and the movement of the moving wall 28 It is preferable to use a material that allows the movement of the material.

The rubber material is preferably a material that can withstand long-term storage. For example, IIR, butyl rubber, E
PR, EPDM, EPT, fluoro rubber, thermoplastic elastomer and the like. [Inkjet recording head storage container] Next, the inkjet recording head storage container of the present invention will be described.

(Seventh Embodiment) FIG. 9 shows a seventh embodiment of the present invention.
An ink jet recording head storage container 172 of the embodiment is shown. The ink jet recording head storage container 172 has a container main body 174 having an opening 174H formed therein and capable of accommodating the ink jet recording head 12, a lid member 176 capable of closing the opening 174H,
In the container main body 174, the ink drying prevention device 102 of the present invention is disposed. FIG. 9 shows the ink anti-drying device 102 having substantially the same configuration as the ink anti-drying device 152 of the fifth embodiment, but the pin 146 is integrated with the ink jet recording head 12 during the accommodation process. The difference is that they are moved to. That is, a slide member (not shown) that is pushed by the inkjet recording head 12 and slides downward is provided in the container body 174 when the inkjet recording head 12 is set from above and moves downward. A pin 146 protrudes from the member.

An elastic member 188 made of an elastic material such as rubber is attached to the lid member 186.
The elastic member 188 contacts the upper surface of the ink jet recording head 12 by the operation of closing the lid member 176, and presses the ink jet recording head 12 downward at least in a state where the contact member 104 is in close contact with the ink ejection surface 14,
Increases adhesion.

The ink drying prevention device constituting the ink jet recording head storage container 182 of the seventh embodiment is not limited to the above-described one, but may be any of the ink drying prevention devices of the respective embodiments of the present invention. You may.

In the ink jet recording head storage container 182 according to the seventh embodiment having such a configuration, the ink jet recording head 12 can be stored and stored inside the container main body 184.

In the operation of accommodating the ink jet recording head 12, as shown in FIG. 9A, the ink jet recording head 12 is set at a predetermined position in the container body 184, and the ink jet recording head 12 is moved downward. Then, the pin 146 also moves downward. Therefore, the link 144 presses the side wall 20 </ b> S of the inkjet recording head 12, and the convex meniscus 2
2 are formed. Further, the ink jet recording head 12
Is moved downward, as shown in FIG. 9B, the contact member 104 comes into close contact with the ink ejection surface 14 and the ink ejection port 1 is moved.
Sealing 6 prevents drying of the ink. Since the contact member 104 is brought into close contact with the ink ejection surface 14 after the formation of the convex meniscus 22, air does not exist in the nozzle 18 and the evaporation of ink in the nozzle 18 can be reliably prevented. [Inkjet Recording Apparatus] Next, the inkjet recording apparatus of the present invention will be described.

(Eighth Embodiment) FIG. 10 shows an ink jet recording apparatus 182 according to an eighth embodiment of the present invention.

The ink jet recording apparatus 182 includes an ink jet recording head 12 and ejection means 44 arranged in the ink jet recording head 12 in accordance with an image signal.
(Not shown) and a moving unit 1 for moving the inkjet recording head 12 according to an image signal.
84, and a conveying means 186 such as an automatic sheet feeder for conveying the recording paper P. The moving unit 184 is fixed to a carriage section 184A on which the inkjet recording head 12 is mounted and a housing 182H of the inkjet recording apparatus 182, and the carriage section 184A.
And a drive shaft 184C to which a carriage 184A is attached. In the vicinity of the standby area of the inkjet recording head 12, the ink drying prevention device 102 of the present invention is disposed. Although FIG. 10 shows the ink drying prevention device 162 having the same configuration as that of the sixth embodiment as the ink drying prevention device, the ink drying prevention device provided in the inkjet recording device 182 is the same as the ink drying prevention device of the present invention. It is not particularly limited as long as it is a device.

Further, a cleaning means constituted by a blade 188 is arranged near the ink drying prevention device 102. When the ink jet recording head 12 is located at the maintenance position, the blade 188 moves so that unnecessary ink attached to the ink ejection surface 14 can be removed. Further, the maintenance device 190 performs maintenance on the ink jet recording head 12 so that desired printing performance can be maintained.

In the ink jet recording apparatus 182 according to the eighth embodiment having such a configuration, at the time of image recording, ink is supplied to the ink jet recording head 12 according to an image signal.
The ink is ejected from the ink ejection port 16 (see FIGS. 1 and 8), and the inkjet recording head 12 is moved along the carriage shaft 184B by the drive belt. Further, the recording paper P is also moved in an arbitrary direction (generally, a direction orthogonal to the moving direction of the ink jet recording head 12) by the transport means 186. Through these operations, images such as pictures and characters are recorded on the recording paper P.

When the ink jet recording device 182 enters the non-image recording mode or is turned off, the ink jet recording head 12 returns to the standby area. Then, after a convex meniscus is formed in the ink ejection port 16 (in the present embodiment, the ink drying prevention device 16 of the sixth embodiment is used).
2, the convex meniscus 22 (see FIG. 8B) is formed by driving the ejection unit 44, the cap member 103 is raised by the support member 108, and the close contact member 104 is moved to the ink ejection surface 14. To seal the ink ejection port 16. Thereby, drying of the ink in the nozzle 18 is prevented. Moreover, since the contact member 104 is brought into close contact with the ink ejection surface 14 after the formation of the convex meniscus 22, there is no air in the nozzle 18 and the evaporation of the ink in the nozzle 18 can be reliably prevented.

[0112]

[Example 1] In Example 1, a test for confirming the effect of preventing ink drying was performed using the ink drying prevention device 152 (see Fig. 7) of the fifth embodiment of the present invention.

As the ink jet recording head 12,
An aqueous thermal ink jet recording head (using an aqueous ink and ejecting ink droplets by thermal energy from a heating element) was used. The side wall 20S has a thickness of 0.8
mm of PE (polyethylene) to provide the necessary and sufficient flexibility.

As the contact member 104, a silicone rubber having a hardness of 5 ° was formed into a size capable of covering all the ink discharge ports 16 of the ink jet recording head 12, and was mounted on a support table 109 of a support member 108.

The interlocking operation by the interlocking mechanism 147 is based on the contact surface of the contact member 104 with the ink ejection surface 14 and the ink ejection surface 1.
The link 144 presses against the side wall 20S of the ink chamber 20 when the distance to the ink chamber 20 approaches 0.5 mm, and when the distance is 0.1 mm, the pressure from the link 144 becomes maximum and the ink chamber 20 Was designed to increase the internal pressure by 5%.

When the capping operation was performed by the ink drying prevention device 152 having the above-described configuration,
When the distance between the ink ejection surface 14 and the ink ejection surface 14 was 0.1 mm, the convex meniscus 22 that had grown gradually came into contact with the adhesion member 104, and was immediately in a capping state.

In this state, after leaving for one month, the capping was released, the ink jet recording head 12 was attached to the ink jet recording apparatus, and the image was recorded without performing the maintenance operation (vacuum). And high quality images could be obtained.

Comparative Example 1 An ink drying prevention device having the same configuration as that of Example 1 except that the convex meniscus forming means 107 (such as the lever 144) was not provided was prepared, and a confirmation test of the ink drying prevention effect was performed under the same conditions. went.

After leaving for one month, the capping was released and the image was recorded. As a result, missing dots and blurring were conspicuous.
Vacuum was required to resolve this and restore the normal condition. Similarly, when the nozzle 18 of the ink jet recording head 12 for observation was observed, the ink receded to the ink chamber 20 side from the ink discharge port 16 and the surface became high in viscosity.

[Embodiment 2] In Embodiment 2, the eighth embodiment of the present invention will be described.
In the ink jet recording apparatus 182 of the embodiment, a confirmation test of the ink drying prevention effect was performed using the ink drying prevention apparatus 162 (see FIG. 8).

As the discharge means 44 of the ink jet recording head 12, one using a multilayer piezoelectric element of a piezoelectric sintered body of BaTiO ₃ (barium titanate) is prepared, and the discharge means 44 is provided with a convex meniscus forming means 107. It was configured to double.

The voltage applied to the ejection means 44 at the time of forming the convex meniscus has a gradient of the voltage change at the time of ejection reduced to 1/10 compared with the applied voltage waveform at the time of ejection of the ink droplet. As a result, a convex meniscus 22 is formed, and the generation and ejection of ink droplets are prevented.

As the negative pressure generating means, a polyurethane foam was used.

Except for the above, the configuration was the same as that of the first embodiment. However, in order to confirm the effect of negative pressure cancellation, paper dust was adhered to the ink ejection surface 14 to form a state of poor sealing.

In the capping operation, the convex meniscus 22
Was formed, the contact member 104 was brought into close contact with the ink ejection surface 14 to seal the ink ejection port 16, and thereafter the negative pressure was canceled. During the capping, the negative pressure canceled state is always maintained.

In this state, after leaving for one month, the capping was released. To release the capping, first, the negative pressure was canceled by the negative pressure canceling means 34 to generate a negative pressure. 14 was carried out.

Then, the maintenance operation (vacuum)
When image recording was performed without performing the above, a high quality image could be obtained without missing dots.

[Comparative Example 2] For comparison, in the ink jet recording apparatus 182 and the ink drying preventing apparatus 162 having the same configuration as in Example 2, capping was released after leaving the apparatus for one month without operating the negative pressure canceling means 34. However, when the image was recorded without performing the vacuum maintenance, the missing dots occurred in almost all the positions corresponding to the nozzles 18.

Thereafter, even if vacuum was applied, 20% of the nozzles 18 did not recover to the normal state.

Then, when the ink jet recording head 12 was disassembled and observed, the nozzle 18 which had not been recovered had no ink and was solidified while being drawn into the ink chamber 20 side.

[0131]

According to the present invention, since the cap member is brought into close contact with the ink discharge surface, drying of the ink can be reliably prevented for a long period of time, and air is not forced into the nozzle.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a basic configuration of an ink drying prevention device according to the present invention, in which (A) shows a state before sealing an ink discharge port, and (B) shows a state in which an ink discharge port is being sealed. (C) shows a state where the ink discharge port is sealed.

FIG. 2 is a cross-sectional view showing, in an enlarged manner, the vicinity of the ink discharge port in a state where the ink discharge port is sealed in the ink drying prevention device of the present invention.

FIGS. 3A and 3B are cross-sectional views schematically showing the ink drying prevention device according to the first embodiment of the present invention, wherein FIG. 3A shows a state before the ink discharge port is sealed, and FIG. (C) shows a state in which the ink discharge port is sealed, respectively.

FIG. 4 is a cross-sectional view schematically illustrating an ink drying prevention device according to a second embodiment of the present invention in a state before an ink ejection port is sealed.

FIG. 5 is a cross-sectional view schematically showing an ink drying prevention device according to a third embodiment of the present invention in a state before an ink ejection port is sealed.

6A and 6B are cross-sectional views schematically showing an ink drying prevention device according to a fourth embodiment of the present invention, wherein FIG. 6A is a state before sealing an ink discharge port, and FIG. (C) shows a state in which the ink discharge port is sealed, respectively.

FIGS. 7A and 7B are cross-sectional views schematically showing an ink drying prevention device according to a fifth embodiment of the present invention, wherein FIG. 7A shows a state before the ink discharge port is sealed, and FIG. (C) shows a state in which the ink discharge port is sealed, respectively.

FIGS. 8A and 8B are cross-sectional views schematically showing an ink drying prevention device according to a sixth embodiment of the present invention, wherein FIG. 8A shows a state before the ink discharge ports are sealed, and FIG. (C) shows a state in which the ink discharge ports are sealed, respectively.

FIGS. 9A and 9B are cross-sectional views illustrating an ink jet recording head storage container according to a seventh embodiment of the present invention, wherein FIG. 9A is a state in which the ink jet recording head is being stored, and FIG. Indicates the status.

FIG. 10 is a sectional view illustrating a schematic configuration of an inkjet recording apparatus according to an eighth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Ink jet recording head 14 Ink ejection surface 16 Ink ejection opening 18 Nozzle 20 Ink chamber 22 Convex meniscus 28 Moving wall 30 Electrode 32 Negative pressure generating means 34 Negative pressure canceling means 40 Porous body (Negative pressure generating means) 44 Piezoelectric element (Negative) Pressure generating means, discharge means) 102 ink drying prevention device 103 cap member 104 adhesion member (cap member) 107 convex meniscus forming device 112 ink drying prevention device 117 pressing member (convex meniscus forming device) 122 ink drying prevention device 127 heater (heating) Means, convex meniscus forming means) 132 Ink drying prevention device 142 Ink drying preventing device 147 Interlocking mechanism (convex meniscus forming means) 152 Ink drying prevention device 154 Negative pressure switching interlocking mechanism 162 Ink drying prevention device 172 Ink jet printing Head storage container 182 ink jet recording apparatus

Continued on the front page (72) Inventor Tetsu Mohri 2274 Hongo, Ebina-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd.Ebina Office (72) Inventor Hiroaki Sato 2274 Hongo, Ebina-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd. ) Inventor Yasushi Oki 2274 Hongo, Ebina-shi, Kanagawa Prefecture F-Terminus at Ebina Office of Fuji Xerox Co., Ltd. 2C056 EA17 FA04 HA06 HA15 JA04 JA10 KB08 KB11 KC10 KC11 KC16 KC27

Claims (15)

[Claims] 1. An ink drying prevention device for preventing drying of ink inside an ink jet recording head which discharges ink droplets from an ink discharge port, wherein a convex meniscus formation for forming a convex meniscus of the ink at the ink discharge port is provided. Means, and a cap member that seals the ink ejection port in close contact with the ink ejection surface of the ink jet recording head in a state where the convex meniscus is formed in the ink ejection port by the convex meniscus forming means. Ink drying prevention device. 2. An ink jet recording head comprising an ink chamber for storing ink, wherein drying of the ink can be prevented corresponding to the ink jet recording head having the ink chamber. 2. The ink drying prevention device according to 1. 3. The ink drying prevention device according to claim 2, wherein the convex meniscus forming means includes an internal pressure increasing means for increasing an internal pressure of the ink chamber. 4. The ink drying prevention device according to claim 2, wherein the convex meniscus forming means includes a volume reducing means for reducing a volume of the ink chamber. . 5. The ink drying method according to claim 1, wherein the convex meniscus forming means includes a piezoelectric element provided on the ink jet recording head. Prevention device. 6. A negative pressure generating means for keeping the ink chamber in a constant negative pressure state, between the negative pressure state in the ink chamber and a substantially atmospheric pressure state closer to the atmospheric pressure than the negative pressure state. The ink drying prevention device according to any one of claims 2 to 5, further comprising: a switching unit configured to switch between: 7. The apparatus according to claim 6, wherein said switching means is capable of switching said ink chamber to said substantially atmospheric pressure state after said ink discharge port is sealed by said cap member. Ink drying prevention device. 8. The ink supply device according to claim 6, wherein the switching unit is configured to switch the ink chamber to the negative pressure state when the cap member is separated from the ink ejection surface. 8. The ink drying prevention device according to 7. 9. The ink according to claim 6, wherein the negative pressure generating means includes a liquid absorbing member provided in the ink chamber. Drying prevention device. 10. The ink drying device according to claim 9, wherein the switching unit is an opening / closing member that opens and closes a communication hole that communicates the inside of the ink chamber of the inkjet recording head with the outside. Prevention device. 11. An ink jet recording head storage container comprising the ink drying prevention device according to any one of claims 1 to 10. 12. An ink jet recording apparatus comprising the ink drying prevention device according to claim 1. 13. An ink drying prevention method for preventing drying of ink inside an ink jet recording head using the ink drying prevention device according to any one of claims 1 to 10, wherein the convex meniscus formation is performed. A convex meniscus forming step of forming a convex meniscus of the ink at the ink discharge port by means, and the cap member on the ink discharge surface in a state where the convex meniscus is formed at the ink discharge port by the convex meniscus forming step. A capping step of sealing the ink discharge ports by bringing them into close contact with each other, and a method for preventing ink drying. 14. An ink drying prevention method for preventing drying of ink inside an ink jet recording head by using the ink drying prevention device according to claim 7, wherein the ink ejection port is sealed by the cap member. An ink drying prevention method, wherein the ink chamber is brought into the substantially atmospheric pressure state by the switching means later. 15. An ink drying prevention method for preventing drying of ink inside an ink jet recording head using the ink drying prevention device according to claim 8, wherein the switching means switches the negative pressure in the ink chamber. An ink drying prevention method, wherein the capping member is separated from the ink ejection surface after the state is set.