JP2001158104A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink jet recording head in which clogging due to dry-up of ink can be prevented through a simple arrangement and sealing liquid can be removed and resupplied surely at a low cost. SOLUTION: A voltage is applied to a drive means before a recording head 18 enters a rest mode and a rotary shaft 62 is rotated to cause rotation of an eccentric cam 60. The eccentric cam 60 presses an air gap member 52 while rotating to decrease the volume thereof and impregnated sealing liquid 34 is pushed out from the top face 52B and applied onto the nozzle face 28. Since a voltage is not applied to the drive means before the recording head 18 enters a print mode, the eccentric cam 60 is not rotated. When the nozzle face 28 slides on the air gap member 52 under that state, the sealing liquid 34 applied onto the nozzle face 28 is sucked because the content of the sealing liquid 34 is low on the top face 52B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, an FA
More particularly, the present invention relates to an ink jet recording apparatus that records an image by discharging aqueous ink onto paper.

[0002]

2. Description of the Related Art In a conventional ink jet recording apparatus, it is a major problem to prevent nozzle clogging due to drying and thickening of ink during non-operation. Various ink materials have been developed to solve this problem, but it is still difficult to reduce evaporation of the ink solvent.

For this reason, in a commercially available ink jet recording apparatus, the nozzle is shielded from the outside air by a resin capping means or the like during non-printing or during a long period of non-operation, thereby delaying the drying of the ink.

However, this capping means requires a complicated procedure and apparatus in order to more effectively improve the airtight state of the nozzle. Also, with this capping means, the nozzle cannot be completely shielded from the air, and during storage, the drying and thickening of the ink inside the nozzle gradually progress, which may cause nozzle clogging. is there.

[0005] For this reason, as means for avoiding the problem caused by clogging after long-term suspension, Japanese Patent Application Laid-Open No. 52-1041 has been proposed.
As disclosed in Japanese Patent Publication No. 30, there is known a method of sealing an ink discharge port to shield ink from air by means of a seal liquid insoluble in ink and a means for forming a film of the seal liquid to prevent the ink from drying. Have been.

Japanese Patent Application Laid-Open No. 49-115548 discloses that a seal liquid and a wetting mechanism seal an ink discharge port when a printing apparatus is not operating, and a seal liquid is provided by a switch provided in a seal liquid supply path during operation. Close the supply channel of
A method for preventing a sealing liquid from being supplied to an ink ejection port is described.

Here, since the ink is attached to the ink discharge port, if the supply member for supplying the sealing liquid directly touches the ink discharge port, the ink adheres to the supply member and the life of the supply member is shortened. Become.

For this reason, in the above-described invention, a plate or the like is disposed at a position facing the ink discharge port, and a gap is provided between the ink discharge port and the plate so that the plate does not touch the ink discharge port. The seal liquid is indirectly applied to the ink ejection ports by flowing the seal liquid into the gap.

However, a mechanism for flowing or removing the sealing liquid in the gap is required separately, and the apparatus becomes complicated.

On the other hand, JP-A-54-69436 and JP-A-5-177841 use a magnetic fluid as a seal liquid, and control the removal and resupply of the magnetic fluid to the nozzle surface by a magnetic force. .

However, a dispersant or a surfactant is usually used in the magnetic fluid in order to stably disperse the magnetic particles in a dispersion medium. For this reason, there is a danger that the ink dissolves in the magnetic fluid or the magnetic fluid is emulsified.

In addition, the magnetic fluid is expensive, and an external force such as opening and closing by a pump, an electromagnet, and a support is required to switch between a state in which the nozzle surface is sealed by the magnetic fluid and a state in which the nozzle is unsealed. Complicated head structure,
This leads to an increase in the size of the printing device.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described circumstances, and has as its object to provide an ink jet recording apparatus which can prevent clogging due to ink drying with a simple structure and can supply a sealing liquid at low cost. Make it an issue.

[0014]

According to the first aspect of the present invention, a recording head that records an image by ejecting ink from a nozzle surface toward a recording sheet based on image information suspends ejection of ink. Before entering the sleep mode, the sealing liquid flows out of the gap member and is supplied to the nozzle surface.

The gap member is held by a seal liquid holding section, and a seal liquid for preventing drying of the ink is supplied from the seal liquid holding section, and the gap liquid is impregnated with the seal liquid.

Further, at least a portion of the gap member that comes into contact with the nozzle surface is coated with an ink-repellent porous resin. For this reason, the ink adhered to the nozzle surface does not permeate into the gap member and the inside of the gap member is not contaminated. As described above, by covering the portion that comes into contact with the nozzle surface with the ink-repellent resin, the gap member can directly contact the nozzle surface.

According to the second aspect of the present invention, the sealing liquid is exuded from the portion in contact with the nozzle surface by the exuding means. As an exuding means, for example, an airbag in which gas is sealed in a bag of a thin film of a resin material or a rubber material is provided inside the gap member, and the gap member is impregnated by utilizing the volume expansion and contraction of the gas in the airbag by controlling the temperature. There is a method of exuding the sealed liquid that has been leaked.

Here, in order to efficiently exude the sealing liquid only at a portion that comes into contact with the nozzle surface, a portion other than this portion may be coated with a coating material so as not to exude the sealing liquid.

According to the third aspect of the present invention, the exuding means comprises:
This is pressing means for pressing the gap member. As described above, when the gap member is pressed by using the pressing means,
The volume of the air gap member is reduced, and the sealing liquid impregnated therein can be pushed out from the portion in contact with the nozzle surface.

According to the invention described in claim 4, the pressing means includes:
Before the recording head enters the pause mode, the gap member is pressed to exude the impregnated seal liquid from a portion that comes into contact with the nozzle surface, and the recording head is pressed into the gap member before entering the printing mode in which ink is ejected. The pressing force is released, and the gap liquid absorbs the sealing liquid supplied to the nozzle surface.

As described above, by changing the timing of pressing the gap member, the volume of the gap member is changed,
The sealing liquid can be oozed out of the gap member, or the sealing liquid can be absorbed inside.

Therefore, the supply and absorption of the sealing liquid can be performed by one member, and the absorbed sealing liquid can be easily reused. In addition, even when a high-viscosity sealing liquid is applied thickly with emphasis on the sealing performance of the nozzle surface, the ink can be discharged smoothly because the sealing liquid on the nozzle surface is absorbed.

Accordingly, since a high-viscosity sealing liquid can be used, the sealing liquid becomes non-volatile for a long period of time, and the sealing performance against clogging can be maintained.

According to the fifth aspect of the present invention, the sealing liquid is caused to flow from the portion in contact with the nozzle surface to the sealing liquid holding portion by utilizing the capillary force of the gap member itself.

Specifically, by making the diameter of the gap on the side of the seal liquid holding portion smaller than that of the portion contacting the nozzle surface, the space between the portion contacting the nozzle surface and the sealing liquid holding portion is utilized by utilizing the capillary force. The sealing liquid can be made to flow and the absorption efficiency of the sealing liquid can be increased.

[0026]

FIG. 1 shows an ink jet recording apparatus 10 according to this embodiment. A pair of chassis 12 is provided in the inkjet recording apparatus 10,
A carriage shaft 14 is provided orthogonal to the chassis 12. A carriage feed belt 16 is provided in parallel with the carriage shaft 14.

A carriage 13 guided by a carriage shaft 14 is fixed to the carriage feed belt 16. When the recording head 18 is loaded on the carriage 13, the recording head 18 moves along the carriage shaft 14.

On the other hand, the paper feed shaft 2
0 is rotatably supported in a state perpendicular to the chassis 12, and a paper feed roller 22 for transporting the recording paper P is fixed to the paper feed shaft 20. Therefore, the recording paper P is transported in a direction orthogonal to the direction in which the recording head 18 moves. A nozzle 25 is located below the recording head 18.
Is provided, and as shown in FIG.
The fifth nozzle surface 28 is provided with a plurality of ink chambers 30 for storing the ink 24.

The inner diameter (nozzle diameter) of the ink chamber 30 is 35 μm.
m, and the ink ejection port 26 of the ink chamber 30
The ink 24 is ejected toward the recording paper P (see FIG. 1), and the ink 24 adheres to the recording paper P, so that pictures, characters, and the like can be printed.

FIGS. 2A, 2B and 2C show the basic structure of the nozzle 25. FIG. 2A shows a plan view of the nozzle 25, and FIG. 2B shows a cross-sectional view taken along line AA of FIG. 2A.

In the figure, a nozzle surface 28 provided with an ink discharge port 26 is arranged at the upper part.
The droplet is ejected in the direction of gravity (downward).

On the other hand, the recording head 18 is provided with an ink supply means (not shown), and the ink 24 is supplied to the ink chamber 30 from the ink supply means (not shown) by a capillary force or a pressure difference.

An ink discharge means 32 is provided on the outer peripheral surface of the ink chamber 30. This ink ejection means 32
Numeral denotes a discharge unit of a thermal ink jet system, which is provided with a heater (not shown) on the outer peripheral surface of the ink chamber 30.

The heater is constituted by, for example, laminating a protective layer made of tantalum on a heating element layer made of polycrystalline silicon, and applying a predetermined signal at a timing corresponding to an image signal by a signal applying means (not shown). It is wired to be. When this heater is heated, the volatile components contained in the ink 24 evaporate instantaneously, generating bubbles, and the ink 24 is discharged from the ink discharge ports 26.

Although the ink discharging means 32 is provided on the outer peripheral surface of the ink chamber 30 here, it is not always necessary to provide the ink discharging means 32 on the outer peripheral surface, and may be provided on a part of the bottom surface of the ink chamber 30.

Further, a piezoelectric element method may be used as the ink discharging means. The ink chamber or a wall constituting an ink flow path leading to the ink chamber is formed of a member through which deformation of the piezoelectric element can be propagated. A voltage is applied to the piezoelectric element according to an image signal, and the ink is ejected by the distortion.

Further, the shape of the ink discharge port 26 is not limited to a circle, and the effect is not changed even if the shape is an arbitrary shape such as an ellipse or a polygon.

On the other hand, the sealing liquid 34 is
Is applied so that the ink 24 in the ink discharge port 26 does not come into contact with air. This sealing liquid 34
Is a seal liquid 34 and ink 24 to maintain performance.
And the seal liquid 34 must not spontaneously emulsify with the ink 24.

In order for the sealing liquid 34 to be incompatible with the ink 24, the solubility of the sealing liquid 34 in the ink 24 may be 0.1 wt% or less at room temperature (25 ° C.).

When the recording head 18 is in the rest mode in which the discharge of the ink 24 is stopped (the recording head 18 is located at the home position), the sealing liquid 34 does not evaporate from the nozzle surface 28. Need to be sexual. Non-volatile at normal temperature means that the vapor pressure is not more than 0.1 mmHg at 25 ° C.

The kinematic viscosity of the sealing liquid 34 is 1 to
The range is 1000 mm ² / s. In addition, the sealing liquid 3
4 can be used if the surface tension is in the range of 15 to 70 mN / m.
N / m or less, and desirably less than the surface tension of the ink 24 used.

When used by penetrating into a porous fluororesin as a covering material 36 (see FIG. 3) described later, 2
It is preferably at most 5 mN / m. Of course, any liquid suitable for these properties can be used,
A plurality of materials can be mixed and adjusted for viscosity and surface tension before use.

Seal liquid 3 when using water-based ink
As 4, organic solvents and oils that are liquid at normal temperature can be used. For example, octane, nonane, tetradecane, hydrocarbons such as dodecane, oleic acid, higher fatty acids such as linoleic acid, n-decanol, water-insoluble alcohols such as dimethylbutanol, dibutyl phthalate,
In addition to plasticizers such as dibutyl maleate, vegetable oils, mineral oils, silicone oils, fluorine oils and the like can also be used. These may be used alone or in combination of two or more as long as they can be mixed uniformly.

As shown in FIG. 2B, the seal liquid 34 applied to the nozzle surface 28 comes into contact with the ink 24 in the ink discharge port 26 to form a film of the seal liquid 34 on the nozzle surface 28.

The film thickness of the seal liquid 34 depends on the ink chamber 3
Although it can be appropriately selected depending on the inner diameter of 0 or the storage period for preventing clogging, etc., considering sufficient sealing performance and a practical supply and removal process of the sealing liquid 34, 5 μm or more and 200 μm or less are appropriate. And more preferably 20 μm or more and 100 μm or less.

Next, the ink jet recording apparatus 10 according to the first embodiment will be described.

As shown in FIGS. 1 and 3, the recording head 1
On the movement trajectory 8, for example, a rectangular parallelepiped gap member 52 and a seal liquid holding portion 53 that holds the gap member 52 are provided.

The gap member 52 has a continuous gap structure, and the inside thereof is impregnated with the sealing liquid 34. The gap member 52 only needs to be able to be impregnated with the sealing liquid 34, and may have a continuous gap porous structure (for example, sponge) or a structure provided with a continuous thin flow path (for example, fiber material or paper material).

As specific materials, non-woven fabric, felt,
A material which does not cause a problem such as deterioration due to the sealing liquid 34 can be selected from porous elastic materials such as cloth and synthetic resin material. For example, when the sealing liquid 34 is silicone oil, foamed polyurethane or the like can be used.

As an example of the gap member 52, a member in which the surface of a base material 51 formed in a rectangular parallelepiped shape is covered with an ink-repellent and porous coating material 36 is exemplified. This covering material 36
Accordingly, the nozzle surface 28 does not directly rub against the base material 51, so that the contamination and the supply failure of the seal liquid 34 due to the adhesion of the ink 24 to the base material 51 can be prevented.

The covering material 36 may be any material as long as it can block the passage of the ink 24 and does not cause a reaction, deterioration or the like in contact with the seal liquid 34.
Various polymer materials such as acrylic resin are suitably used.

On the other hand, below the gap member 52, a seal liquid holding portion 53 in which the seal liquid 34 is stored is provided. As shown in FIG. 4, the top surface 52B of the gap member 52
Before the recording head 18 enters the pause mode, when the recording head moves from the recording area to the home position (in the direction of arrow A), the recording head 18 is rubbed by the nozzle surface 28.

At this time, the surface of the top surface 52B is crushed, the volume of the gap member 52 is reduced, and the sealing liquid 34 impregnated inside is extruded. Then, the nozzle surface 28 separates from the top surface 52B, restores the volume, and sends the sealing liquid 34 to the bottom surface 52A.

The gap member 52 is moved from the top surface 52B to the bottom surface 52B.
As going to A, the average void diameter is reduced. Thereby, the capillary force is increased from the top surface 52B of the gap member 52 to the bottom surface 52A, and the sealing liquid 34 is transferred to the top surface 5B.
2B toward the bottom surface 52A, the sealing liquid 3
4, the absorption efficiency can be increased.

Here, in order to make the average void diameter of the bottom surface 52A of the void member 52 smaller than the average void diameter of the top surface 52B, even if a base material having such properties is manufactured. good. Further, a plurality of porous members having different void diameters may be joined in order of the void diameter size.

Further, as shown in FIG. 5B, a mortar-shaped case 70 having a cross-sectional area that becomes smaller toward the back.
And a porous member 7 having a uniform pore diameter shown in FIG.
2 is pressed into this case 70.

As a result, as shown in FIG.
The porous member 72 may be compressed and deformed toward the bottom of the case 70, and the porous member 73 may be formed such that the average void diameter at the back of the case 70 is reduced.

According to this method, it is easy to manufacture a porous member having a different average pore diameter depending on the position of the cross section, and at the same time,
This is preferable in that the porous member 73 can be stably installed by press fitting. Alternatively, a protrusion may be provided at the bottom of the case and press-fitted. Further, the case 70 may be formed of a porous material to function as a sealing liquid holding portion.

Here, as shown in FIGS. 4, 6A and 6B, the nozzle surface 28 is
In order for the seal liquid 34 to be supplied to the nozzle surface 28 in close contact, the positional relationship between the nozzle surface 28 of the recording head 18 and the top surface 52B of the gap member 52 overlaps in the vertical direction. The optimum overlap amount depends on the material, shape and size of the gap member 52, the sliding speed of the recording head 18, and the like, but is preferably about 0.5 to 3 mm.

As a modification of the gap member 52 according to the first embodiment, as shown in FIG.
The covering material 76 may be bonded to the top surface 74A of the fourth.

Further, since it is sufficient that the nozzle surface 28 can rub the gap member 52, it is not necessary to make surface contact, and line contact may be used. For this reason, as shown in FIG.
The base portion 80 having a curved top surface may be covered with the covering material 81 as long as there is a linear portion at the position where the surface rubs.

Here, an example of the coating material is a porous fluororesin.

The porous fluororesin used in the present invention includes polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), tetrafluoroethylene ethylene copolymer (ETFE), polychlorotrifluoroethylene, and tetrafluoroethylene. / Hexafluoropropylene copolymer, tetrafluoroethylene /
Polymers such as an ethylene copolymer and a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer can be used.

Baking at a temperature around the melting point of the polymer particles,
By performing the sintering process, the polymer particles are partially fused or sintered to the extent that the original shape of the polymer particles is retained, thereby forming an integral porous network.

The average pore diameter is determined mainly in consideration of the surface tension of the sealing liquid and ink used, but is preferably 0.01 to 1
00 μm, more preferably 0.1 to 50 μm. Here, the average void diameter means a void of a member in contact with the sealing liquid, and is not necessarily a pore diameter of the porous fluororesin membrane itself.

When a film-like material is formed by lamination,
Alternatively, in the case of forming with a fiber material or a mesh material coated with a porous fluororesin, the average gap diameter takes into account the gaps in the laminated portion and the gaps formed between the fibers.

As a preferable one satisfying the above conditions, the unfired PTFE film is stretched at a temperature lower than the melting point of PTFE to make it porous, and then, while maintaining the stretched state, the PTFE film is stretched.
There are stretched porous PTFE obtained by calcining and stretching at a temperature equal to or higher than the melting point of FE, and so-called PTFE paper obtained by making fibrous powder obtained by pulverizing PTFE.
These film-like materials can cover the surface of various materials by the above-mentioned bonding method such as adhesion and fusion.

As still another form, a molded product obtained by subjecting PTFE molding powder as a raw material to low-pressure compression molding and then firing at a temperature equal to or higher than the melting point of PTFE can be applied. While the above three methods are all porous PTFE films,
Since it is selected as a molded body, the seal liquid regulating means can be manufactured as a single member, and a relatively complicated shape can be easily manufactured, and a bonding process such as adhesion and fusion is not required, and as a member, Reliability is improved.

Also, by changing the type and particle size of the molding powder, the gap diameter and the gap density can be controlled, so that an optimum removing member can be manufactured. Further, by controlling the pressure distribution and the filling amount of the raw material at the time of compression molding, it is also possible to change the above-mentioned average pore diameter.

As still another form, a porous film can be formed on the surface by using a high heat-resistant material such as metal, glass, ceramic or the like as a core material, applying a fluororesin polymer to the core material and firing it. It is.

If the core material is made of metal fiber, glass fiber, carbon fiber, or the like, it is possible to form a film-shaped fiber entangled body whose opening diameter and opening ratio can be freely set by performing processing such as plain weaving. Alternatively, a fluororesin polymer may be applied to the film and fired.

It is also possible to use the fiber material previously coated with a porous fluororesin. According to this aspect, since a core having high mechanical strength can be used, a failure due to mechanical fatigue due to rubbing and compression can be significantly reduced.

Further, for coating the porous fluororesin with another material or laminating the porous fluororesins, for example, a silicone adhesive, a fluorine adhesive such as PFA or FEP, a urethane adhesive or the like is used. For example, using a gravure pattern roll or the like, it is possible to use a bonding method of partially bonding in, for example, a dot shape, a line shape, a grid shape, or the like, or a heat fusion method. Since the adhesive has oil resistance, it is suitable when oils such as silicone oil are used as the sealing liquid.

Next, an ink jet recording apparatus according to the second embodiment will be described.

Here, the gap member 52 used in the first embodiment is used, and the gap member 5 is pressed by a pressing means described later.
2 to press the sealing liquid 34 impregnated into the gap member 52 from the top surface 52B.
2 to release the sealing liquid 3 into the gap member 52.
Absorb 4. Therefore, the description of the gap member 52 is omitted.

As shown in FIG. 8 (A), for example, the side surface of a rectangular parallelepiped gap member 52 is
Are arranged in a state of being inscribed in the side wall 58A. Also,
Inner wall 58 of seal liquid holding portion 58 with gap member 52 interposed
An eccentric cam 60 as an example of a pressing unit is provided at a position facing A.

When the gap member 52 is pressed by the eccentric cam 60, the gap member 52 is deformed between the inner wall 58A and the eccentric cam 60.

The eccentric cam 60 is fixed to a rotating shaft 62 which is rotatably supported by a driving means (not shown). Depending on the eccentric position and the cam diameter, the eccentric cam 60 may rotate during one rotation of the rotating shaft 62. A state where the cam 60 presses the gap member 52 and a state where the cam 60 separates from the gap member 52 are set.

Specifically, the recording head 18 (see FIG. 1)
Is located in the recording area (print mode), the eccentric cam 60 is located away from the gap member 52,
The recording head 18 enters the sleep mode (the direction of arrow A (FIG. 1)
Before the voltage is applied to the driving means, the rotating shaft 62 rotates. The rotation of the rotating shaft 62 causes the eccentric cam 60 to rotate.
Rotates in the direction of the arrow.

As a result, as shown in FIG.
The eccentric cam 60 presses the gap member 52 while rotating.
Therefore, the volume of the gap member 52 is reduced, and the sealing liquid 34 impregnated therein is pushed out from the top surface 52B of the gap member 52. The gap member 52 is provided with a sealing liquid holding portion 58.
The sealing liquid 34 pushed out from the top surface 52B is prevented from leaking.

Next, the nozzle surface 28 of the recording head 18 rubs against the top surface 52B of the gap member 52, and the sealing liquid 34 is applied to the nozzle surface 28. Then, when the eccentric cam 60 further rotates, as shown in FIG.
0 moves away from the gap member 52. Therefore, the gap member 52
Is restored, and the sealing liquid 34 on the top surface 52B is
Absorbed to 2A side.

Before the recording head 18 enters the print mode (in the direction of arrow B (see FIG. 1)), no voltage is applied to the drive means, so that the eccentric cam 60 does not rotate. Therefore,
The eccentric cam 60 remains separated from the gap member 52.

On the other hand, the gap member 52 has a smaller average gap diameter from the top surface 52B to the bottom surface 52A.
Thereby, the top surface 52B of the gap member 52 is moved from the bottom surface 52B.
A, the capillary force is increased toward A, and the sealing liquid 34 is caused to flow from the top surface 52B toward the bottom surface 52A, thereby increasing the absorption efficiency of the sealing liquid 34.

For this reason, if the nozzle surface 28 rubs against the top surface 52B of the gap member 52 before the recording head 18 enters the print mode, the impregnation rate of the sealing liquid 34 on the top surface 52B becomes low. The seal liquid 34 applied to the nozzle surface 28 is reliably absorbed.

As described above, by changing the timing of pressing the gap member 52, the volume of the gap member 52 is changed, and the sealing liquid 34 is removed from the top surface 52 B of the gap member 52.
Can be exuded or the sealing liquid 34 can be absorbed inside.

Thus, the supply and absorption of the sealing liquid 34 can be performed by one member, and the absorbed sealing liquid 34 can be easily reused. In addition, nozzle surface 2
8 with high emphasis on the sealing performance, the sealing liquid 34 on the nozzle surface 28 is thickened even if the high viscosity sealing liquid 34 is applied.
Therefore, the ink 24 can be discharged smoothly.

Therefore, since the sealing liquid 34 having a high viscosity can be used, the sealing liquid 34 becomes non-volatile for a long period of time, and the sealing performance against clogging can be maintained.

Here, the eccentric cam 60 is used as the pressing means, but the pressing means is not limited to this, and the gap member 52 may be deformed by pressing using a solenoid or a spring material. Alternatively, these means may be provided inside the gap member 52, and a rigid member may be arranged on the outside to press and deform the gap member 52 from the inside.

Further, the object can be achieved by heating the gap member 52 and exuding due to a decrease in the viscosity of the sealing liquid 34 held in the gap member 52.

As another form, an airbag in which a gas is sealed in a thin film bag of a resin material or a rubber material is provided inside the gap member 52, and the volume expansion and contraction of the gas in the airbag is controlled by controlling the temperature. Thus, the sealing liquid 34 impregnated in the gap member 52 can be exuded.

In this case, the filling amount of the sealing liquid 34 impregnated inside the gap member 52 is 30 to 95 with respect to the gap.
% Is preferable. If this ratio is too large, when the gas mixed into the gap member 52 expands due to environmental temperature and pressure changes, the increase in volume is reduced by the sealing liquid holding portion 58.
Overflow may cause leakage of the sealing liquid 34 into the gap member 52.

Conversely, if the filling amount of the sealing liquid 34 impregnated into the space member 52 is less than 30% of the space, the amount of the sealing liquid 34 is too small, and the pressing member is operated. Even if it does, the seepage of the seal liquid 34 to the top surface 52B is insufficient, and there is a possibility that the seal liquid 34 cannot be sufficiently supplied to the nozzle surface 28.

Further, the sealing liquid holding portion 58 does not necessarily need to be a member or a material different from the gap member 52. However,
When the sealing liquid 34 is used as a separate member, the sealing liquid 34 can be put into a container as it is to form the sealing liquid holding portion 58. However, the danger of the inkjet recording apparatus 10 being tilted or leakage of the sealing liquid 34 during transportation is considered. Then, a porous elastic material such as a nonwoven fabric, felt, cloth, or a synthetic resin material is preferably placed in a container and impregnated and held with the sealing liquid.

[0094]

Next, the specifications of the present invention will be described with reference to examples. However, the present invention is not limited to this.

First, the ink jet recording apparatus according to the first embodiment will be described.

As shown in FIG. 1, a recording head 18 is provided in the ink jet recording apparatus 10, and TIJ (thermal ink jet method) is used as a discharge means of the recording head 18.

The recording head 18 is provided with a plurality of ink discharge ports 26 from which the ink 24 is discharged.
6 has an inner diameter (nozzle diameter) of 35 μm. The ink 24 is ejected from the ink ejection port 26 toward the recording paper P.

A seal liquid 34 is applied to the nozzle surface 28 so that the ink 24 in the ink discharge port 26 does not come into contact with air. The sealing liquid 34 is prepared by mixing a plurality of types of silicone oils, and has a kinematic viscosity of 30 mm ² / s, a surface tension of 20 mN / m, a vapor pressure of 0.1 mmHg or less (25 ° C.) and is non-volatile. .

In order to maintain the performance of the seal liquid 34, the seal liquid 34 and the ink 24 are not compatible with each other, and do not spontaneously emulsify with the ink 24. The sealing liquid 34 having the above properties is coated with a film thickness of 5
It is applied to the nozzle surface 28 before entering the rest mode at 0 μm.

In FIG. 3, a base member 51 made of silicone sponge is used as a gap member.
Also, it is molded so that the hardness becomes 35 ± 3 °. As a result, it is possible to obtain an adhesion property that is important for realizing good removal performance and a rigidity that is important for precisely controlling the film thickness of the sealing liquid 34.

Further, a portion other than the bottom surface of the base material 51 was covered with a porous PTFE film having stainless steel metal fiber as a core material as the covering material 36. Therefore, the nozzle surface does not directly rub the substrate 51. Further, since the PTFE film has ink repellency, the ink 2
4 will not be sucked.

The inside of the gap member 52 (porous PTF)
E film and silicone sponge) are previously impregnated with the sealing liquid 34 at a filling rate of 80% with respect to the voids.

Here, the porous PTFE film is obtained by sintering PTFE powder on a film-like fiber entangled body made of plain-woven stainless steel metal fiber, and having an average pore diameter of 50 μm.
It is formed so that Then, a porous PTFE film is bonded to the silicone sponge by heat fusion.

Next, the sealing liquid regulating means according to the second embodiment will be described.

As shown in FIG. 8A, the side surface of the gap member 52 is placed in a state of being in contact with the side wall 58A of the sealing liquid holding portion 58 of the box. Further, an eccentric cam 60 as a pressing means is provided at a position facing the inner wall 58A of the seal liquid holding portion 58 with the gap member 52 interposed therebetween.

When the recording head 18 (see FIG. 1) is in the print mode, the eccentric cam 60 is arranged at a distance from the gap member 52. A voltage is applied, and the rotating shaft 62 rotates. The rotation of the rotation shaft 62 causes the eccentric cam 60 to rotate in the direction of the arrow.

As a result, as shown in FIG.
The eccentric cam 60 presses the gap member 52 while rotating.
Therefore, the volume of the gap member 52 is reduced, and the sealing liquid 34 impregnated therein is pushed out from the top surface 52B. Since the gap member 52 is disposed in the seal liquid holding portion 58,
Leakage of the sealing liquid 34 pushed out from the top surface 52B is prevented.

Next, the nozzle surface 28 of the recording head 18 rubs against the top surface 42B of the gap member 52, and the sealing liquid 34 is applied to the nozzle surface 28. Then, when the eccentric cam 60 further rotates, as shown in FIG.
0 moves away from the gap member 52. Therefore, the gap member 52
Is restored, and the sealing liquid 34 on the top surface 52B is absorbed.

Before the recording head 18 enters the printing mode, no voltage is applied to the driving means.
0 does not rotate. Therefore, the eccentric cam 60 is provided with the gap member 52.
Stay away from

In this state, the nozzle surface 28 is
When the top surface 52B is rubbed, the sealing liquid 34 applied to the nozzle surface 28 is reliably absorbed because the impregnation rate of the sealing liquid 34 on the top surface 52B is low.

[0111]

According to the present invention having the above-described structure, according to the first aspect of the present invention, it is possible that the ink adhered to the nozzle surface seeps into the inside of the gap member and contaminates the inside of the gap member. Absent. As described above, by covering the portion that comes into contact with the nozzle surface with the ink-repellent resin, the gap member can directly contact the nozzle surface. According to the second aspect of the present invention, for example, an airbag in which a gas is sealed in a bag of a resin material or a rubber material is provided inside the gap member, and the volume expansion and contraction of the gas in the airbag is utilized by controlling the temperature. Thus, the sealing liquid impregnated in the gap member can be exuded. According to the third and fourth aspects of the present invention, when the gap member is pressed, the volume of the gap member is reduced, and the sealing liquid impregnated therein can be pushed out from the portion in contact with the nozzle surface. The supply and absorption of the sealing liquid can be performed by one member, and the absorbed sealing liquid can be easily reused. According to the fifth aspect of the present invention, the sealing liquid can be made to flow from the portion in contact with the nozzle surface to the sealing liquid holding portion by utilizing the capillary force, and the efficiency of absorbing the sealing liquid can be increased.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an ink jet recording apparatus according to an embodiment.

FIG. 2 is a diagram illustrating a nozzle surface of a recording head used in the ink jet recording apparatus according to the embodiment, and FIG.
Is a plan view, (B) is an AA sectional view of (A), and (C) is a perspective view.

FIG. 3 is a perspective view showing a gap member and a seal liquid holding portion used in the ink jet recording apparatus according to the first embodiment.

FIG. 4 is a diagram illustrating a state in which a seal liquid is supplied to a nozzle surface by a gap member used in the inkjet recording apparatus according to the first embodiment.

5A and 5B are diagrams showing a method of changing a gap diameter of a gap member, wherein FIG. 5A shows a porous member, FIG. 5B shows a case in which the porous member can be press-fitted, and FIG. It is a figure showing the state pressed into the case.

6A and 6B are diagrams illustrating a positional relationship between a recording head and a seal liquid regulating unit used in the ink jet recording apparatus according to the first embodiment, FIG. 6A is a front view, and FIG.
It is a side view.

FIG. 7A is a perspective view showing a modified example of a gap member used in the ink jet recording apparatus according to the first embodiment, and FIG. 7B is a perspective view showing another modified example.

8A and 8B are diagrams illustrating a pressing unit used in the ink jet recording apparatus according to the second embodiment. FIG. 8A is a diagram illustrating a state where the eccentric cam is separated from a gap member, and FIG.
FIG. 4 is a diagram showing a state in which the eccentric cam is pressing the gap member.

[Explanation of symbols]

 Reference Signs List 10 inkjet recording device 51 base material (gap member) 52 gap member 53 seal liquid holding part 58 seal liquid holding part 60 eccentric cam (pressing means) 62 rotating shaft (pressing means) 72 porous member (gap member) 74 base material (Void member) 80 Base material (Void member)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Susumu Hirata 430 Nakai-cho, Nakai-machi, Ashigara-gun, Kanagawa Prefecture Inside Fuji Xerox Fuji Xerox Co., Ltd. (72) Inventor Yuji Suemitsu 430 Sakai Nakaicho, Ashigarashimo-gun, Kanagawa Prefecture Inside Green Tech Nakajima Fuji Xerox Co., Ltd. (72) Inventor Megumi Hasebe 430 Sakai Nakaicho Sakaigami, Kanagawa Pref. Tetsu Mohri 430 Sakai, Nakai-machi, Ashigara-gun, Kanagawa Green Tech Naka Fuji Xerox Co., Ltd. F-term (reference) 2C056 EA17 JA24

Claims (5)

[Claims] 1. An ink jet recording apparatus comprising a recording head for recording an image by discharging ink from a nozzle surface toward a recording sheet based on image information, wherein the recording head is impregnated with a seal liquid for preventing drying of the ink. At least a portion in contact with the nozzle surface is coated with an ink-repellent porous resin, and the seal liquid oozes out to supply the seal liquid to the nozzle surface before entering a pause mode in which the ink discharge is paused. An ink jet recording apparatus, comprising: a gap member that holds the gap member; and a seal liquid holding section that holds the gap member and supplies the seal liquid to the gap member. 2. The ink jet recording apparatus according to claim 1, further comprising an exuding unit that exudes the sealing liquid from a portion that contacts the nozzle surface. 3. The ink jet recording apparatus according to claim 2, wherein the exuding unit is a pressing unit that presses the gap member. 4. The pressing means presses the gap member before the recording head enters the pause mode, causing the impregnated sealing liquid to seep out from a position in contact with the nozzle surface, and 4. The ink jet recording apparatus according to claim 3, wherein the pressing force on the gap member is released before entering the printing mode in which the ink is ejected, and the seal liquid supplied to the nozzle surface is absorbed by the gap member. . 5. Using the capillary force of the gap member itself,
The ink jet recording apparatus according to any one of claims 1 to 4, wherein the seal liquid is caused to flow from a position in contact with the nozzle surface toward the seal liquid holding unit.