JP3603694B2 - Ink jet recording device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink jet recording apparatus having a recording head for ejecting ink droplets corresponding to print data, and more particularly, to sealing a nozzle forming surface of the recording head and receiving a negative pressure from a suction pump. The present invention relates to an ink jet recording apparatus having a capping unit for sucking and discharging ink from the recording head.
[0002]
[Prior art]
Ink jet recording apparatuses have been used in many types of printing, including color printing, in recent years because the noise during printing is relatively low and small dots can be formed with 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 a recording sheet relatively to the recording head, and performs printing while moving the recording head. Recording is performed by ejecting ink droplets on recording paper based on the data.
[0003]
The carriage is equipped with a recording head that can eject, for example, black, yellow, cyan, and magenta inks.Full-color printing is possible by changing the ejection ratio of each color ink as well as text printing using black ink. I have to.
[0004]
The above-described ink jet recording head performs printing by discharging ink pressurized in the pressure generating chamber from the nozzle opening as ink droplets onto recording paper, and increases the ink viscosity due to evaporation of the solvent from the nozzle opening. In addition, there is a problem that clogging of nozzle openings occurs due to solidification of ink, adhesion of dust, and mixing of air bubbles, resulting in poor printing.
[0005]
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 drying of the ink in the nozzle openings in the recording head, but also seals the nozzle forming surface by the capping means when the nozzle openings are clogged and sucks. It also has a function of recovering the ink discharge capability that eliminates clogging of the nozzle openings by sucking ink from the nozzle openings by negative pressure from the pump.
[0006]
The forcible suction and discharge of ink to eliminate clogging of the recording head is called a cleaning operation. For example, when printing is restarted after a long pause of the apparatus, or when a user recognizes a printing defect and performs cleaning, for example, the cleaning operation is performed. This is executed when a switch is operated, etc., and after applying a negative pressure by a suction pump to suck and discharge ink from the recording head into the capping means, the nozzle forming surface is formed by a wiping member formed of, for example, a rubber material. A wiping operation is performed.
[0007]
By the way, the capping means used in this type of ink jet recording apparatus is configured as shown in FIGS. 7 and 8, for example. 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.
[0008]
As shown in FIGS. 7 and 8, the capping means 8 includes a rectangular cap holder 9 having an open upper surface, and a cap formed of a flexible substance having ink resistance and housed in the cap holder 9. A member 7 is provided. 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.
[0009]
Further, 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 the lower bottom portion of the cap holder 9 is provided, and when the carriage moves to the capping means side, the slider 10 is moved upward while maintaining the slider 10 in a substantially horizontal posture by the action of a rotating arm (not shown) or the like. The nozzle forming surface of the recording head 5 can be sealed by the projection 7b by moving the nozzle.
[0010]
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 reaching a suction pump is connected.
[0011]
In the above-described configuration, when the carriage moves to the capping unit side, the slider 10 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.
[0012]
At the time when the ink suction from the recording head 5 is completed, the capping means 6 is slightly moved downward to release the sealing of the recording head by the cap member 7 and to operate a suction pump (not shown). An operation sequence for discharging the ink stored in the cap member 7 is executed.
[0013]
[Problems to be solved by the invention]
According to the capping means 6 having the above-described configuration, the cap member 7 is formed of an elastic member such as rubber or an elastomer in order 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.
[0014]
Therefore, when suctioning ink from the nozzle openings 5a with a negative pressure inside the cap member 7 is performed, there arises a problem that the cap member 7 is deformed inward due to the negative pressure as shown in FIGS. .
[0015]
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. , That is, the load on the carriage motor is reduced. However, the lower the elasticity of the material of the cap member 7, the more remarkable the degree of the deformation described above.
[0016]
In addition, recently, the number of nozzle openings 5a provided on the nozzle forming surface of the recording head has also increased, and accordingly, the suction capacity of the suction pump has been increased. The maximum negative pressure at the time may reach about -0.8 atm.
[0017]
Under such conditions, the projection 7a of the cap member 7 is deformed so as to fall inward, and furthermore, in this state, the projection 7a of the cap member 7 is pressed against the nozzle forming surface, so that an effect is given. Furthermore, the protruding portion 7a is further deformed inwardly.
[0018]
For this reason, the sealing portion formed by the protruding portion 7a of the cap member 7 reaches the nozzle opening 5a as shown in FIG. 8, and the normal ink suction operation from the nozzle opening cannot be performed. Occurs.
[0019]
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 a capping unit 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 image quality.
[0020]
[Means for Solving the Problems]
In order to achieve the above object, an ink jet recording apparatus according to the present invention, which seals a nozzle forming surface of an ink jet recording head for ejecting ink droplets corresponding to print data and a nozzle forming surface of the recording head. An ink jet type recording apparatus comprising: a capping unit that receives a negative pressure from a suction pump to suction and discharge ink from a recording head, wherein the capping unit is in contact with a nozzle forming surface of the recording head and has a nozzle forming surface. A cap member formed of a soft material for sealing the cap member, and a cap holder formed of a hard material for holding the cap member, wherein the cap member is provided with respect to an opening end face of the cap holder for sealing the nozzle forming surface. And the cap holder is raised from the inner surface of the cap holder. The cap member is insert-molded into the cap holder so as to fill a space formed by the L-shape of the reinforcing rib and further cover the inner surface of the reinforcing rib. Alternatively, they are integrally formed by two-color molding, and the projection of the cap member is formed immediately above the reinforcing rib.
Further, it is preferable that the cap member formed so as to protrude from the opening end face of the cap holder has a substantially triangular cross-sectional shape of the protruding portion.
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 or rubber material is used as the soft material constituting the cap member. Can be
According to the ink jet recording apparatus having the above configuration, the cap member formed on the inner surface of the cap holder fills the space formed by the reinforcing rib rising upward in an L shape from the inner surface of the cap holder, In addition, since the reinforcing ribs are integrally formed so as to cover the inner side 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, and It is possible to reduce the degree of the member falling down inside.
In addition, since the cap member is configured to fill the space formed by the reinforcing ribs rising upward in an L-shape from the inner surface of the cap holder, the structure of the cap member filled in this space is Acts so as to pull the protrusion abutting on the recording head outward, thereby synergistically reducing the cap member falling down 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 replaced by the cap holder in the space. Therefore, the mechanical tightness can be ensured, so that the action of pulling the projecting portion of the cap member in the outward direction can be ensured.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
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 as viewed from the top of the apparatus, and FIGS. 2 and 3 show a state as viewed from the side, showing a non-capping state and a capping state, respectively.
[0027]
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 to the paper guide plate 3. The carriage 1 is coupled to a part of a timing belt (not shown) reciprocated by a carriage motor, and is configured to reciprocate along the guide rod 2.
[0028]
A recording head 5 is mounted on the carriage 1 so as to face a recording sheet 4 arranged on the upper surface of the sheet guide plate 3, and ink is introduced into the recording head 5 to correspond to print data. The recording paper 4 on the paper guide plate 3 can be printed by ejecting ink droplets.
[0029]
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. 7, a function for sealing the nozzle forming surface of the recording head 5 during non-printing to prevent drying of the ink at the nozzle openings, and a function of receiving a negative pressure from a suction pump (not shown) during the cleaning operation. A function for forcibly discharging ink.
[0030]
As shown in FIG. 1, an ink discharge port 7a is formed in the inner bottom of the cap member 7 arranged in the capping means 6, and the ink discharge port 7a has a tube similar to the structure described in FIG. One end of the tube is connected and the other end of the tube is connected to a suction pump. Thus, when printing is not performed, the nozzle forming surface of the recording head 5 is sealed by the cap member 7. When a cleaning command is received, a negative pressure by the suction pump is applied to the internal space of the capping unit, and recording is performed. The ink can be forcibly discharged from the head 5. An ink absorbing sheet 8 is accommodated in the cap member 7 so as to hold the sucked ink.
[0031]
The cap member 7 is formed integrally with a rectangular cap holder 9 as will be described later in detail. Are formed in the horizontal direction, respectively. The cap holder 9 is mounted on a slider 10 constituting a lifting mechanism, and is urged toward the recording head 5 by a pair of compression springs 11 interposed between the slider 10 and the spring receiving portion 9a. It is attached with.
[0032]
Engagement portions 9b are formed on the center of one end of the cap holder 9 and on both sides of the other end, respectively. These three engagement portions 9b are respectively provided on the respective locking members formed on the slider 10. By being locked at three points by 10a, the cap holder 9 is mounted on the slider 10 while its movement in the upward direction, that is, toward the recording head 5, is restricted.
[0033]
A pair of elongated holes 12 are formed in the lower bottom portion of the slider 10 in a substantially horizontal direction, and an arm rotatably attached to the frame 13 is provided in each elongated hole 12. A pair of horizontal shafts 15 arranged on the free end side of 14 are housed movably, respectively. Thus, the slider 10 can rise up with an arc-shaped locus with respect to the frame 13 via the arm 14.
[0034]
Guide pieces 10b are formed on both sides of the non-printing area side end of the slider 10, and the pair of guide pieces 10b are supported by a pair of guide grooves 16 formed in the frame 13. It is configured to: The guide groove 16 is composed of a low portion 16a formed at one end, a horizontal high portion 16b formed at the other end, and an inclined portion 16c connecting these. The regions are formed to communicate with each other.
[0035]
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. It is urged so as to be located in the area direction and in the direction away from the recording head 5, that is, in the downward direction in this embodiment.
[0036]
Then, as shown in FIG. 2, when the carriage 1 moves directly above the capping means 6, the engaging body 1 a arranged on the carriage 1 comes into contact with the engaging portion 10 c formed to stand upright on the slider 10. As shown in FIG. 3, the slider 10 rises through the arm 14 while resisting the pulling force of the spring 17, whereby the cap member 7 formed integrally with the cap holder 9 is disposed on the carriage 1. The nozzle forming surface of the recording head 5 can be sealed.
[0037]
When the carriage 1 moves to the printing area side, the contact 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 is pulled by the tension of the spring 17 as shown in FIG. 2, the sealing of the nozzle forming surface of the recording head 5 by the cap member 7 is released.
[0038]
As shown in FIG. 2, the sealing surface of the cap member 7, that is, the upper end surface that comes into contact with the nozzle forming surface of the recording head 5 is configured to be non-parallel to the nozzle forming surface of the recording head 5. Have been. 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).
[0039]
This is based on the relationship between the position of the horizontal shaft 15 in the elongated hole 12 formed in the slider 10 and the position of the guide piece 10b that slides in a series of guide grooves 16 formed in the frame 13. Have been.
[0040]
When the cap member 7 seals the nozzle forming surface of the recording head 5, the cap member 7 first comes into contact with the nozzle forming surface from the home position side, and the recording is performed in accordance with the compression action of the compression spring 11 as the slider 10 moves up. It acts so as to seal the entire surface of the nozzle 5 of the head 5. Further, when the cap member 7 is to unseal the nozzle forming surface of the recording head 5, first, the cap member 7 is separated from the nozzle forming surface of the recording head 5, away from the end on the printing area side, and It acts to separate in a non-parallel state.
[0041]
On the other hand, as shown in FIG. 1 or FIG. 3, on the printing area side adjacent to the capping means 6, the nozzle forming surface of the recording head 5 mounted on the carriage 1 is wiped with the movement of the carriage 1, for example, rubber A cleaner holding member 20 provided with a flexible wiping member 21 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 from the wiping position on the moving path of the recording head 5.
[0042]
Therefore, during the cleaning operation, the wiping member 21 removes dust, paper dust, and the like adhering to the nozzle forming surface of the recording head 5 before sucking the ink, and removes the nozzle forming surface after sucking the ink. The ink adhering to is wiped off.
[0043]
In this case, in the embodiment, the movement of the holding member 20 that holds the wiping member 21 and the pump that sucks the internal space of the capping unit to a negative pressure convey the recording paper 4 on the paper guide plate 3. The driving force of a paper feed motor (not shown) 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.
[0044]
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 engaging body 1a arranged on the carriage 1 is moved to the engaging portion 10c formed on the slider 10. Abut Then, as the carriage 1 still moves to the home position side, the slider 10 stands up through the arm 14 while resisting the tensile force of the spring 17 as shown in FIG. On the other hand, the guide piece 10b formed on the slider 10 moves from the low portion 16a constituting the guide groove 16 to the inclined portion 16c, and further to the horizontal high portion 16b, thereby being integrally formed with the cap holder 9. The cap member 7 seals the recording head 5 arranged on the carriage 1.
[0045]
In this way, at the stage where the sealing of the nozzle forming surface by the cap member 7 is completed, the communication with the atmosphere is cut off and the cap member 7 becomes airtight, and the evaporation of the ink from the nozzle openings is suppressed, and the recording is performed. Acts to prevent head clogging.
[0046]
When the carriage 1 moves to the printing area side by driving of the carriage motor, the engagement body 1a arranged on the carriage 1 separates from the engagement portion 10c formed on the slider 10. Accordingly, the slider 10 is lowered by the tensile force of the spring 17 through the arm 14 and by the guide piece 10b formed on the slider 10 moving toward the lower portion 16a. Thereby, the sealing state of the recording head 5 by the cap member 7 is released.
[0047]
FIGS. 4 and 5 show the detailed configuration of the cap holder and the cap member that constitute the capping means described above. 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 as viewed from the line AA in FIG. 1 to 3 are denoted by the same reference numerals.
[0048]
As described above, the cap member 7 is integrally formed on the inner side of the rectangular cap holder 9 by, for example, insert molding or two-color molding, and the cap holder 9 is formed of, for example, a hard synthetic resin. The cap member 7 is made of a soft material such as an elastomer or rubber.
[0049]
In the case where 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 the second mold, and the cap member 7 is further formed. Are molded integrally by insert molding of the soft material constituting the above.
[0050]
In the case where the two are integrally formed by two-color molding, first, the cap holder 9 is first molded in a predetermined mold, and a space formed by the cap holder 9 as a primary molded product and the secondary molding cavity. By filling the inside with the soft material constituting the cap member 7, both are integrally formed.
[0051]
As shown in FIG. 5, on the inner side surface of the cap holder 9 that is primarily formed, the cap member 7 that is secondarily formed is formed to protrude from the opening end surface 9 c of the cap holder 9. As shown in an enlarged view of a main part in FIG. 6, the cross-sectional shape of the protruding portion 7b of the cap member 7 has a substantially triangular shape, and the end surface of the top abuts on the nozzle forming surface of the recording head. It constitutes a seal part. 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.
[0052]
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 an inner surface 9d thereof, and the inner surface 9d of the cap holder 9 and the reinforcing rib are formed. 9e, a space 9f is formed. Then, as described above, the cap member 7 is insert-molded or two-color molded with respect to the cap holder 9, so that the cap member 7 fills the space 9f and further covers the inner side surface 9g of the reinforcing rib 9e. And are integrally formed.
[0053]
In addition, on the inner surface of the cap holder 9, the protruding portion 7 b of the cap member 7 formed so as to protrude from the opening end surface 9 c of the cap holder 9 is located immediately above the L-shaped reinforcing rib 9 e rising from the inner surface of the cap holder 9. Is formed.
[0054]
In this manner, the reinforcing rib 9e which rises upward in an L-shape from the inner surface 9d of the cap holder 9 is formed, so that the reinforcing rib 9e acts as a support for the cap member, and capping is performed during the cleaning operation. Even if a negative pressure is applied to the internal space of the means, it acts to effectively prevent the cap member 7 from falling inward.
[0055]
Moreover, 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 space 9f is filled. The structure of the cap member acts to pull the protruding portion 7b abutting on the recording head outward, thereby synergistically reducing the phenomenon of the cap member 7 falling inward.
[0056]
Further, by forming the cap member 7 integrally with the cap holder 9 by insert molding or two-color molding, it is possible to secure mechanical adhesion of the cap member structure filled in the space 9f. Accordingly, the action of pulling the protruding portion 7b of the cap member 7 in the outward direction can be ensured.
[0057]
【The invention's effect】
As is apparent from the above description, according to the ink jet recording apparatus of the present invention, the cap member is filled in the space formed by the L-shape of the reinforcing rib of the cap holder, and further covers the inner surface of the reinforcing rib. As described above, the cap member is integrally formed by insert molding or two-color molding, and the projection of the cap member is formed immediately above the reinforcing rib. Therefore, when a negative pressure is generated during the cleaning operation, the sealing portion of the cap member is formed. By pulling the cap member outward, the cap member can be effectively prevented from falling inward. Accordingly, it is possible to avoid the 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 a 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 the 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 the configuration and problems of a conventional capping means.
FIG. 8 is a plan view schematically showing the configuration and problems of a conventional capping means.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 carriage 2 guide rod 3 paper guide plate 4 recording paper 5 recording head 6 capping means 7 cap member 7a ink discharge port 7b protrusion 9 cap holder 9c open end face 9d holder inner side face 9e reinforcing rib 9f space section 9g reinforcing rib inner side face 10 Slider 11 Compression spring 13 Frame 21 Wiping member

Claims (3)

An ink jet recording head for ejecting ink droplets corresponding to print data; sealing a nozzle forming surface of the recording head; and sucking and discharging ink from the recording head by receiving a negative pressure from a suction pump. An ink jet recording apparatus comprising capping means,
The capping means includes a cap member formed of a soft material that abuts on the nozzle forming surface of the recording head and seals the nozzle forming surface, and a cap holder formed of a hard material holding the cap member. Provided,
The cap member is formed with a protruding portion protruding from an opening end surface of a cap holder that seals the nozzle forming surface,
The cap holder has a reinforcing rib that rises upward in an L-shape from an inner surface of the cap holder,
The cap member is formed integrally with the cap holder by insert molding or two-color molding so as to fill a space formed by the L-shape of the reinforcing rib and further cover an inner surface of the reinforcing rib. ,
The protrusion of the cap member is formed immediately above the reinforcing rib. 2. The ink jet recording apparatus according to claim 1, wherein the cap member formed so as to protrude from an opening end face of the cap holder has a substantially triangular cross section. 3. The ink jet recording apparatus according to claim 1, wherein the soft material forming the cap member is an elastomer or a rubber.

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