JP2001096758A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording apparatus capable of certainly performing cleaning operation sucking and discharging ink from the nozzle orifices of a recording head. SOLUTION: In a capping means 6 having function sealing the nozzle forming surface of a recording head to apply negative pressure, a cap holder 9 and a cap member 7 are formed, for example, by two-color molding. The cap member 7 is constituted so as to fill the space part formed by the reinforcing rib rising upwardly in an L-shape from the inner surface of the cap holder 9 to further cover the inner surface of the reinforcing rib. By this constitution, the cap member 7 is prevented from falling inwardly by the negative pressure at the time of cleaning operation and the seal part of the cap member 7 reaches the nozzle orifice parts of the recording head to avoid such a problem that the normal suction operation of ink from nozzle orifices is obstructed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus having a recording head for discharging ink droplets corresponding to print data, and more particularly to a method of sealing a nozzle forming surface of a recording head and a suction pump. The present invention relates to an ink jet recording apparatus provided with a capping means for sucking and discharging ink from the recording head by receiving a negative pressure from the recording head.

[0002]

2. Description of the Related Art Ink jet recording apparatuses have been used in many printings including color printing in recent years, since noise during printing is relatively small and small dots can be formed at a high density. Such an ink jet recording apparatus includes an ink jet recording head that receives supply of ink from an ink cartridge, and a paper feeding unit that moves recording paper relative to the recording head,
Recording is performed by ejecting ink droplets on recording paper based on print data while moving the recording head.

A recording head capable of discharging, for example, black, yellow, cyan, and magenta inks is mounted on a carriage. Not only text printing using black ink, but also changing the discharge ratio of each color ink allows full-color printing. Printing is enabled.

The above-mentioned ink jet recording head is
Due to the fact that the ink pressurized in the pressure generating chamber is ejected onto the recording paper as ink droplets from the nozzle openings and printing is performed, an increase in ink viscosity due to evaporation of the solvent from the nozzle openings,
There is a problem that clogging of the nozzle opening occurs due to solidification of ink, adhesion of dust, and mixing of air bubbles, resulting in poor printing.

For this purpose, this type of ink jet recording apparatus is provided with capping means for sealing the nozzle forming surface of the recording head during non-printing. The capping means not only functions as a lid for preventing ink from being dried at the nozzle openings in the recording head, but also seals the nozzle forming surface by the capping means when the nozzle openings are clogged when the nozzle openings are clogged. It also has a function of recovering the ink discharge capability that sucks ink from the nozzle openings by negative pressure from the pump and eliminates clogging of the nozzle openings.

[0006] Forcible suction and discharge processing of ink for eliminating clogging of the recording head is called a cleaning operation, and is performed when printing is resumed after a long pause of the apparatus.
This operation is performed when the user recognizes a printing failure and operates, for example, a cleaning switch. After a negative pressure is applied by a suction pump and ink is sucked and discharged from the recording head into the capping unit, the ink is formed from, for example, a rubber material. The wiping member is configured to perform a wiping operation on the nozzle forming surface.

By the way, the capping means used in this type of ink jet recording apparatus is, for example, as shown in FIG.
And a configuration as shown in FIG. FIG. 7 is a longitudinal sectional view of the capping unit in a state where the recording head is capped, and FIG. 8 is a perspective view of the recording head sealed by the capping unit.

As shown in FIGS. 7 and 8, the capping means 8 is a rectangular cap holder 9 having an open upper surface.
And a cap member 7 housed in the cap holder 9 and formed of a flexible material having ink resistance. The upper end of the cap member 7 is slightly protruded from the cap holder 9 to form a protruding portion 7b, which forms a seal surface for the recording head.

In addition, an ink absorbing sheet 8 made of a porous material having excellent ink resistance and ink absorbing property is accommodated in the inner bottom of the cap member 7. Further, a slider 10 for supporting a lower bottom portion of the cap holder 9 is provided, and when the carriage moves to the capping means side,
The slider 10 is actuated by the action of a rotating arm (not shown).
Is moved upward while maintaining a substantially horizontal posture, so that the nozzle forming surface of the recording head 5 can be sealed by the protruding portion 7b.

On the other hand, an ink outlet 7a is formed so as to penetrate the cap member 7, and a tube T connected to the ink outlet 7a and leading to a suction pump is connected.

In the above-described configuration, the carriage 1 moves to the capping means side, so that the slider 1
0 is pushed up, and the protrusion 7 b of the cap member 7 seals the nozzle forming surface of the recording head 5. By operating the suction pump, a negative pressure is applied to the internal space formed by the cap member 7 via the tube T. As a result, ink is sucked from the nozzle openings 5 a of the recording head 5, and the sucked and discharged ink is absorbed by the ink absorbing sheet 8 stored in the cap member 7 and stored in the cap member 7.

When the ink suction from the recording head 5 is completed, the capping means 6 is moved slightly downward to release the sealing of the recording head by the cap member 7 and to operate a suction pump (not shown). By doing
An operation sequence for discharging the ink stored in the cap member 7 is executed.

[0013]

According to the capping means 6 having the above-described structure, the cap member 7 is formed of an elastic member such as rubber or elastomer to seal the nozzle forming surface of the recording head 5. The elasticity of the material can maintain a sealed state with the nozzle forming surface.

Therefore, when it is attempted to suction ink from the nozzle opening 5a by applying a negative pressure to the inside of the cap member 7, the cap member 7 is deformed inward by the negative pressure as shown in FIGS. Occurs.

Generally, the capping means 6 is configured to be able to move up and down with respect to the recording head 5 by the above-mentioned rotating arm or the like based on the movement of the carriage.
By using a low elastic material for the cap member 7, consideration is given to reducing the load of carriage movement, that is, the load on the carriage motor. However, the lower the material of the cap member 7 is, the more remarkable the degree of the above-mentioned deformation is.

In addition, recently, the number of nozzle openings 5a provided on the nozzle forming surface of the recording head has also increased, and the suction capacity of the suction pump has been increased accordingly. The maximum negative pressure at the time of suction by the pump may reach about -0.8 atm.

Under such conditions, the projection 7a of the cap member 7 is deformed so as to fall inward, and in this state, the projection 7a of the cap member 7 is pressed against the nozzle forming surface. As a result, the protruding portion 7a is deformed further inwardly.

For this purpose, the protrusion 7a of the cap member 7
As a result, a problem arises in that the seal formed by the nozzle reaches the nozzle opening 5a as shown in FIG. 8, and a normal ink suction operation from the nozzle opening cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and an object of the present invention is to provide a configuration of capping means capable of preventing a remarkable collapse phenomenon of a cap member. It is an object of the present invention to provide an ink jet recording apparatus with improved reliability.

[0020]

In order to achieve the above-mentioned object, an ink jet recording apparatus according to the present invention comprises: an ink jet recording head for discharging ink droplets corresponding to print data; A capping unit that seals a nozzle forming surface of the head and sucks and discharges ink from the recording head by receiving a negative pressure from a suction pump. A cap member formed of a soft material that contacts the nozzle forming surface of the head and seals the nozzle forming surface, and a cap holder formed of a hard material holding the cap member, wherein the cap member is Is formed on the inner surface of the cap holder so as to protrude from the opening end face of the cap holder, and The cap member fills a space formed by a reinforcing rib rising upward in an L-shape from the inner surface of the cap holder, and is integrally formed so as to cover the inner surface of the reinforcing rib. Is done.

In this case, it is preferable that the cap member formed to project from the opening end face of the cap holder has a substantially triangular cross section. Further, on the inner surface of the cap holder, the protrusion of the cap member formed to protrude from the opening end surface of the cap holder is formed directly above the L-shaped reinforcing rib rising from the inner surface of the cap holder. Is preferred.

The cap member can be integrally formed with the cap holder by insert molding or two-color molding to obtain a preferable operation and effect. In this case, an elastomer is used as a soft material constituting the cap member. Alternatively, a rubber material is used.

According to the ink jet recording apparatus having the above-described structure, the cap member formed on the inner surface of the cap holder has a space formed by the reinforcing rib rising upward in an L shape from the inner surface of the cap holder. Filling,
In addition, since the reinforcing ribs are integrally formed so as to cover the inner surface, even if the internal space of the capping means is sucked by a negative pressure, the reinforcing ribs act as a support for the cap member. In addition, the degree of the inward fall of the cap member can be reduced.

Moreover, since the cap member is configured to fill the space formed by the reinforcing rib rising upward in an L-shape from the inner surface of the cap holder, the cap member filled in this space is The structure acts to pull the projection abutting on the recording head outwardly, thereby synergistically reducing the cap member falling phenomenon.

In this case, by forming the cap member integrally with the cap holder by insert molding or two-color molding, in particular, the structure of the cap member filling the space formed in the cap holder is:
In the space, mechanical adhesion to the cap holder can be ensured, whereby the action of pulling the protrusion of the cap member outward can be ensured.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ink jet recording apparatus according to the present invention will be described based on an embodiment shown in the drawings. FIGS. 1 to 3 mainly show the configuration of capping means in an ink jet recording apparatus to which the present invention is applied. FIG. 1 shows a state viewed from the top of the apparatus, and FIGS. 2 and 3 show states viewed from the side, showing a non-capping state and a capping state, respectively.

Reference numeral 1 shown in FIGS. 2 and 3 denotes a carriage, and the carriage 1 is configured to be guided by a guide rod 2 and move in parallel with the paper guide plate 3. The carriage 1 is connected to a part of a timing belt reciprocated by a carriage motor (not shown), and is configured to reciprocate along the guide rod 2.

A recording head 5 is mounted on the carriage 1 so as to oppose the recording paper 4 disposed on the upper surface of the paper guide plate 3. The recording paper 4 on the paper guide plate 3 can be printed by ejecting ink droplets corresponding to the data.

The capping means 6 for sealing the recording head 5 is disposed in a non-printing area (home position) at the end of the recording apparatus, and has a size capable of sealing the nozzle forming surface of the recording head 5 with a sealed space. A function of sealing the nozzle forming surface of the recording head 5 during non-printing to prevent drying of the ink at the nozzle openings, and recording by receiving a negative pressure from a suction pump (not shown) during the cleaning operation. A function of forcibly discharging ink from the head 5.

As shown in FIG. 1, an ink discharge port 7a is formed at the inner bottom of the cap member 7 disposed in the capping means 6, and the ink discharge port 7a has the same structure as that described in FIG. Is connected to one end of a tube, and the other end of the tube is connected to a suction pump. Thereby, the nozzle forming surface of the recording head 5 is sealed by the cap member 7 during non-printing, and when a cleaning command is received, a negative pressure by the suction pump is applied to the internal space of the capping means, and recording is performed. Ink can be forcibly discharged from the head 5. An ink absorbing sheet 8 is accommodated in the cap member 7.
It is configured to hold the sucked ink by this.

The cap member 7 is formed integrally with a rectangular cap holder 9 as will be described in detail later.
The flat plate-shaped spring receiving portions 9a are respectively formed in the horizontal direction. The cap holder 9 is mounted on a slider 10 constituting a lifting mechanism, and a pair of compression springs 11 interposed between the slider 10 and a spring receiving portion 9a.
And is attached in a state of being biased toward the recording head 5 side.

An engaging portion 9b is formed at the center of one end of the cap holder 9 and on both sides of the other end, and these three engaging portions 9b are formed on the slider 10 respectively. When the cap holder 9 is locked at three points by the locking member 10a, the movement of the cap holder 9 in the upward direction, that is, toward the recording head 5, is restricted.
Mounted on top.

A pair of elongated holes 12 are formed in the lower bottom portion of the slider 10 in a substantially horizontal direction, and each of the elongated holes 12 is rotatably attached to the frame 13. A pair of horizontal shafts 15 arranged on the free end side of the arm 14 are housed so as to be movable. As a result, the slider 10 can rise with an arc-shaped locus with respect to the frame 13 via the arm 14.

Guide pieces 10b are formed on both sides of the end portion of the slider 10 on the non-printing area side, and the pair of guide pieces 10b are formed with a pair of guide grooves 16 formed in the frame 13. It is configured to be supported by. The guide groove 16 has a low portion 16a formed at one end, a horizontal high portion 16b formed at the other end,
Further, it is constituted by an inclined portion 16c connecting these, and these three regions are formed to communicate with each other.

Further, as shown in FIG. 1, one end of a tension spring 17 having one end fixed to the frame 13 is fixed to one guide piece 10b.
By the action of 7, the slider 10 is urged so as to be positioned in the print area direction and in the direction away from the recording head 5, that is, in the downward direction in this embodiment.

Then, as shown in FIG. 2, when the carriage 1 moves just above the capping means 6, the carriage 1
The engaging body 1a disposed on the slider 10 comes into contact with an engaging portion 10c formed to stand upright on the slider 10 so as to resist the tensile force of the spring 17 as shown in FIG.
Is raised via an arm 14 so that the cap member 7 formed integrally with the cap holder 9 can seal the nozzle forming surface of the recording head 5 arranged on the carriage 1. ing.

When the carriage 1 moves to the printing area, the engagement of the engaging body 1a on the carriage 1 with the engaging portion 10c arranged on the slider 10 is released, and the slider 10 pulls the spring 17. The state shown in FIG. 2 is restored by the force, whereby the sealing of the nozzle forming surface of the recording head 5 by the cap member 7 is released.

As shown in FIG. 2, the sealing surface of the cap member 7, that is, the upper end surface which comes into contact with the nozzle forming surface of the recording head 5, is in a non-parallel state to the nozzle forming surface of the recording head 5. It is configured as follows. That is, the sealing surface of the cap member 7 is inclined so as to slightly descend toward the printing area with respect to the end of the home position (right side in FIG. 2).

This is because the long hole 1 formed in the slider 10
2 and the arrangement position of the guide piece 10b that slides in a series of guide grooves 16 formed in the frame 13.

The cap member 7 is connected to the recording head 5
In the state where the nozzle forming surface is sealed, first, the nozzle 10 comes into contact with the nozzle forming surface from the home position side, and the slider 10
As the compression spring 11 contracts as the pressure rises, it acts to seal the entire nozzle forming surface of the recording head 5. In the case where the cap member 7 is to unseal the nozzle forming surface of the recording head 5, the cap member 7 is separated from the nozzle forming surface of the recording head 5 first from the end on the printing region side, and is separated from the nozzle forming surface. It acts to separate in a non-parallel state.

On the other hand, as shown in FIG. 1 or FIG.
A cleaner holding member 20 having, for example, a rubber wiping member 21 for wiping the nozzle forming surface of the recording head 5 mounted on the carriage 1 with the movement of the carriage 1 is disposed. The cleaner holding member 20 is configured to be moved in the horizontal direction so that the wiping member 21 can enter or retract with respect to the wiping position on the moving path of the recording head 5.

Therefore, during the cleaning operation, the wiping member 21 removes dust and paper dust adhering to the nozzle forming surface of the recording head 5 before the ink suction, and after the ink suction. The ink adhering to the nozzle forming surface is wiped.

In this case, in the embodiment, the movement of the holding member 20 for holding the wiping member 21 and the pump for sucking the internal space of the capping means to a negative pressure are performed by the recording paper 4 on the paper guide plate 3. The driving force of a paper feed motor (not shown) for transporting the paper is used. Then, the wiping member 21 is configured to advance on the movement locus of the recording head with the driving of the suction pump.

In the above configuration, when the carriage 1 moves to the non-printing area side by driving the carriage motor,
As shown in FIG. 2, the engagement body 1 disposed on the carriage 1
a comes into contact with the engaging portion 10c formed on the slider 10. Then, as the carriage 1 still moves to the home position side, the slider 10 rises through the arm 14 while resisting the tensile force of the spring 17 as shown in FIG. On the other hand, the guide piece 10 formed on the slider 10
b, the lower portion 16a of the guide groove 16
6c, the cap member 7 is further moved to the horizontal high portion 16b, whereby the cap member 7 integrally formed with the cap holder 9 seals the recording head 5 arranged on the carriage 1.

When the sealing of the nozzle forming surface by the cap member 7 is completed in this way, the cap member 7 is disconnected from the atmosphere and becomes airtight, thereby suppressing the evaporation of ink from the nozzle openings. Thus, the recording head acts to prevent clogging.

When the carriage 1 is moved toward the printing area by driving the carriage motor, the engaging member 1a disposed on the carriage 1 is separated from the engaging portion 10c formed on the slider 10. Therefore, the slider 10 is moved through the arm 14 by the tensile force of the spring 17, and the guide piece 10b formed on the slider 10 is moved to the lower portion 16a.
Descend by moving to the side. Thereby, the sealing state of the recording head 5 by the cap member 7 is released.

FIGS. 4 and 5 show the detailed structure of the cap holder and the cap member constituting the above-mentioned capping means. FIG. 4 is a plan view of the assembly of the cap holder and the cap member as viewed from above, and FIG. 5 is a cross-sectional view of the assembly taken along line AA in FIG. 1 to 3 are denoted by the same reference numerals.

As described above, the cap member 7 is formed integrally with the inside of the rectangular cap holder 9 by, for example, insert molding or two-color molding, and the cap holder 9 is made of, for example, a hard synthetic resin. The cap member 7 is made of a soft material such as an elastomer or rubber.

When both are integrally formed by insert molding, first, the cap holder 9 is formed in a predetermined mold, and the thus formed cap holder 9 is loaded in a second mold. The two are integrally formed by insert-molding the soft material constituting the cap member 7.

In the case where both are integrally formed by two-color molding, first, the cap holder 9 is first molded in a predetermined mold, and the cap holder 9 is formed by the primary molded product, the cap holder 9 and the secondary molding cavity. By filling a soft material constituting the cap member 7 into the space to be formed, both are integrally formed.

As shown in FIG. 5, on the inner surface of the cap holder 9 to be primarily formed, the cap member 7 to be secondary formed is formed to protrude from the opening end face 9c of the cap holder 9. . Then, as shown in an enlarged manner in FIG.
Has a substantially triangular cross-sectional shape, and a top end surface thereof forms a seal portion that abuts the nozzle forming surface of the recording head. With this configuration, the degree of adhesion at the seal portion that comes into contact with the nozzle forming surface of the recording head is improved, so that the sealed state of the internal space of the capping means can be favorably maintained.

Further, as shown in FIG. 6, the cap holder 9 is formed with a reinforcing rib 9e which rises upward in an L-shape from the inner surface 9d thereof. A space 9f is formed between the reinforcing ribs 9e. Then, as described above, the cap member 7 is insert-molded or two-color molded with respect to the cap holder 9, and the cap member 7 fills the space 9f,
In addition, the reinforcing rib 9e is integrally formed so as to cover the inner side surface 9g.

On the inner surface of the cap holder 9, the projecting portion 7b of the cap member 7 formed so as to project from the opening end surface 9c of the cap holder 9 is provided with an L-shaped reinforcing rib rising from the inner surface of the cap holder. 9e.

As described above, by forming the reinforcing rib 9e which rises in an L-shape upward from the inner surface 9d of the cap holder 9, the reinforcing rib 9e acts as a support for the cap member, and the cleaning operation is performed. In some cases, even if a negative pressure is applied to the internal space of the capping means, it acts to effectively prevent the cap member 7 from falling inward.

Further, since the cap member 7 is disposed so as to fill the space 9f formed by the reinforcing rib 9e rising upward in an L-shape from the inner surface of the cap holder 9, the cap member 7 is disposed in the space 9f. The structure of the filled cap member acts to pull the protrusion 7b abutting on the recording head in the outward direction, thereby synergistically reducing the phenomenon of the cap member 7 falling inward. .

Further, by forming the cap member 7 integrally with the cap holder 9 by insert molding or two-color molding, the mechanical adhesion of the cap member structure filled in the space 9f is ensured. This allows the protrusion 7b of the cap member 7 to be
Can be reliably performed in the outward direction.

[0057]

As apparent from the above description, according to the ink jet recording apparatus of the present invention, the cap member is formed on the inner surface of the cap holder so as to protrude from the opening end face of the cap holder. The member is integrally formed so as to fill a space formed by a reinforcing rib rising upward in an L-shape from the inner surface of the cap holder and to further cover the inner surface of the reinforcing rib. Depending on the negative pressure during operation,
It is possible to effectively prevent the cap member from falling inward. Accordingly, it is possible to avoid a problem that the seal portion of the cap member reaches the nozzle opening portion of the recording head and hinders the normal suction operation of the ink from the nozzle opening, thereby improving the reliability of the cleaning operation. It is possible to provide an expression recording device.

[Brief description of the drawings]

FIG. 1 is a plan view mainly showing the configuration of capping means in an ink jet recording apparatus to which the present invention is applied.

FIG. 2 is a side view showing the configuration of the capping means shown in FIG.

FIG. 3 is a side view showing a state in which the recording head is capped by the capping unit shown in FIG.

FIG. 4 is a plan view showing a configuration of a cap holder and a cap member that constitute capping means.

5 is a cross-sectional view of the capping unit shown in FIG. 4 when viewed from the line AA in the direction of the arrow.

FIG. 6 is an enlarged sectional view showing a main part of the capping means shown in FIG. 5;

FIG. 7 is a cross-sectional view schematically showing a configuration and a problem of a conventional capping unit.

FIG. 8 is a plan view schematically showing the configuration and problems of a conventional capping unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Carriage 2 Guide rod 3 Paper guide plate 4 Recording paper 5 Recording head 6 Capping means 7 Cap member 7a Ink outlet 7b Projection part 9 Cap holder 9c Open end surface 9d Holder inner surface 9e Reinforcement rib 9f Space portion 9g Reinforcement rib inner surface 10 Slider 11 Compression spring 13 Frame 21 Wiping member

Claims (5)

[Claims] An ink jet recording head for ejecting ink droplets corresponding to print data; a nozzle forming surface of the recording head being sealed; An ink jet recording apparatus comprising: a capping means for sucking and discharging ink; wherein the capping means includes a cap member formed of a soft material that abuts a nozzle forming surface of a recording head and seals the nozzle forming surface. And a cap holder formed of a hard material for holding the cap member, wherein the cap member is formed on an inner surface of the cap holder so as to protrude from an opening end face of the cap holder, and a cap is provided. The member is a space formed by reinforcing ribs rising upward in an L-shape from the inner surface of the cap holder. An ink jet recording apparatus characterized by being integrally formed as filled, and covers the further inner surfaces of the reinforcing ribs. 2. The ink jet recording apparatus according to claim 1, wherein the cap member formed to project from the opening end surface of the cap holder has a substantially triangular cross section. 3. On the inner surface of the cap holder,
The projection of the cap member, which is formed so as to protrude from the opening end face of the cap holder, is formed immediately above the L-shaped reinforcing rib rising from the inner surface of the cap holder.
Alternatively, the ink jet recording apparatus according to claim 2. 4. The cap member is formed integrally with the cap holder by insert molding or two-color molding.
An ink jet recording apparatus according to any one of the above. 5. The ink jet recording apparatus according to claim 1, wherein the soft material constituting the cap member is an elastomer or a rubber.