JPH09240012A - Ink jet apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet apparatus preventing the destruction of a meniscus at a time of non-recording without incresing cost and capable of preventing the drying of ink in nozzles even during long-term preservation. SOLUTION: A slit part 67 is formed to the bottom surface 66 of the recessed part 65 of a cap main body 64 covering the nozzles of a printing head by a sharp jig and usually closed and opened by applying force to the bottom surface 66. The slit part 67 is planned so as to be opened by force smaller than the force destructing a meinscsus. For example, in the case of a printing head destructing a meniscus by a pressure change of 0.1kg/cm<2> , the slit part 67 is planned so as to be opened by a pressure change of 0.08kg/cm<2> smaller than the destruction pressure change of the meniscus by about 20% to prevent the destruction of the meniscus at a time of non-recording.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet device having an ink jet head for jetting ink from nozzles and a cap member for covering the nozzles when the ink jet head is not driven.

[0002]

2. Description of the Related Art An ink jet printer ejects ink and performs dot recording on a printing paper fed by a paper feeding device. When recording is not performed, an ink jet head is used so that the ink at the nozzles does not dry. Nozzle is covered with a cap to cover the nozzle.

When the cap comes into close contact with the nozzle surface or when the cap is separated from the nozzle surface, a force is applied to the ink meniscus at the nozzle, destroying the meniscus and affecting the ink ejection. Therefore, in order to prevent the destruction of the meniscus, a cap provided with an atmosphere communication hole and a cap connected with a valve mechanism have been proposed.

[0004]

However, in the cap provided with the air communication hole, the inside of the cap communicates with the air even when the nozzle is covered, so that the ink is dried at the nozzle during long-term storage. There was a problem of doing. Further, in the case where the valve mechanism is connected to the cap, there is a problem that the structure becomes complicated and the cost becomes high.

The present invention has been made in order to solve the above problems, and provides an ink ejecting apparatus capable of preventing ink drying at nozzles even during long-term storage without increasing the cost. Is intended.

[0006]

According to a first aspect of the invention, an ink ejecting apparatus having an ink jet head for ejecting ink from a nozzle and a cap member for covering the nozzle when the ink jet head is not driven. In the above, the cap member has a concave portion that forms a space by closely contacting with the inkjet head,
An elastic body forming at least a part of the concave portion and a notch formed in the elastic body, which is normally closed, are opened when a force is applied to the elastic body.

According to the ink jet apparatus of the first aspect, the meniscus is prevented from being broken by opening and closing the cut portion.

Further, in the ink ejecting apparatus of the second aspect, the notch portion is opened before the ink meniscus at the nozzle is destroyed, thereby preventing the meniscus from being destroyed.

Further, in the ink ejecting apparatus of the third aspect, when the pressure of a predetermined value or more is applied to the elastic body, the notch portion is opened to prevent the meniscus from being broken.

Further, in the ink ejecting apparatus of the fourth aspect, when the cap member covers the ink jet head and the ambient temperature changes, the notch portion is opened to prevent destruction of the meniscus. .

Further, in the ink ejecting apparatus of the fifth aspect, the elastic body forms the entire concave portion, so that the structure is simplified.

Further, in the ink ejecting apparatus of the sixth aspect, the ink drying prevention property is improved by forming the elastic body with butyl rubber having a low gas permeability.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the appearance of an ink jet printer.
In, the inkjet printer 1 has a cylindrical platen roller 2 which is rotatably supported by the frame 5 by a rotary shaft (not shown) extending in the left-right direction. The platen roller 2 conveys the print paper 3 supplied from the paper feed cassette or the manual paper feed unit while facing the print head 4, and constitutes a part of the paper feeding device.

The printing paper 3 is supplied in the direction of arrow A from a paper supply port (not shown) behind the frame 5, is fed in the direction of arrow B by the rotation of the platen roller 2, and is supplied from a paper discharge port (not shown). It is configured to be discharged.

A carriage 6 is provided in front of the platen roller 2 so as to be movable in the C direction along the axis of the platen roller 2. The carriage 6 is an ink jet type print head 4 and an ink cartridge 7 containing ink to be supplied to the print head 4 (four colors in this example).
Each is detachably mounted. Further, the carriage 6 has a fitting hole portion 6a slidably fitted to a carriage shaft 8 provided parallel to the axis of the platen roller 2, whereby the print head 4 mounted on the carriage 6 is The platen roller 2 can be reciprocated by sliding along the axis of the platen roller 2. A carriage drive motor 10 that drives the carriage 6 drives the carriage 6 via a belt drive mechanism 14 having a belt 11 and pulleys 12 and 13, and a step motor or a DC motor is used.

Further, on the right side of the platen roller 2, a recovery device RM for recovering the non-ejection or ejection failure of the print head 4 is arranged. Such a recovery device RM is provided because the ink jet type print head 4 is ejected due to, for example, bubbles being generated inside the ink jet head during use or ink droplets adhering to the ejection surface. This is because a defect is caused, so that this is recovered to a good ejection state.

As shown in detail in FIGS. 2 to 5, the recovery device RM includes a wiping device 21 for wiping the nozzle surface of the print head 4, a purging device 22 for sucking defective ink in the print head 4, and a print head. A protective cap device 23 for covering the nozzle surface of No. 4 and preventing ink drying is provided.

The purging device 22 is provided with a suction cap 24 for covering the print head 4 at the front end thereof, and when the print head 4 is covered with the suction cap 24, a negative pressure is generated by the suction pump 25 to perform printing. It is configured to suck the defective ink inside the head 4 to recover a good ejection state. Wiper member 21 of wiping device 21
The advance / retreat of a, the advance / retreat of the suction cap 24 of the purging device 22, and the drive of the suction pump 25 are controlled by rotationally driving the pump cam gear 26. That is, the wiper member 21 a has the rear end portion of the first end of the pump cam gear 26.
The suction pump 25 is controlled by the wiper drive member 32 that engages with the cam groove 26a, and the suction cap 24 of the purging device 22 has its rear end portion engaged with the second cam groove 26b, so that the suction pump 25 has one of them. The rear end portions of the pair of pistons 25a and 25b are respectively controlled by engaging the third and fourth cam grooves 26c and 26d, and by such control, a series of recovery operation is performed. Will be done.

The suction pump 25 includes a suction cap 2
4 and the suction tube 28, one end of the discharge tube 29 is connected, and the other end of the discharge tube 29 is connected to the waste ink tank 31 containing the adsorbent 30. . Therefore, the defective ink in the nozzle of the print head 4 sucked through the suction tube 28 by the suction pump 25 is discharged through the discharge tube 29 to the waste ink tank 31, and the waste ink tank 3
It is adapted to be adsorbed by the adsorbent 30 in the unit 1.

The pump cam gear 26 is driven by a drive means such as a drive motor of the paper feeding device via a connecting means (described in detail below) releasably connected thereto. That is, on one side of the pump cam gear 26, a transmission means such as a gear 26g that meshes with the drive gear 41 connected to the drive means is formed. The gear 26g has a cutout recess 26e formed by removing a part of the outer peripheral teeth.
(FIG. 4) is formed, and during the printing operation of the print head 4 on the printing paper 3, the drive gear 41 is positioned in the cutout recess 26e (origin state), and the gear 26g and the drive gear 41 are formed.
, The pump cam gear 26 is not rotationally driven by the drive motor, and the suction pump 25 and the like are not driven. At the same time, the disk-shaped base plate portion 32 of the pump cam gear 26 is provided with the engagement protrusions 3 protruding in the radial direction.
2a (FIG. 4) is formed, and biasing means, for example, a leaf spring 33 is brought into contact with the engaging convex portion 32a, and the leaf spring 33 rotates the gear 26g in a direction in which the gear 26g is meshed with the drive gear 41. As described above, it is configured to always urge.

Further, the base plate portion 3 of the pump cam gear 26.
2 is formed with a locked portion 32b (FIG. 5) protruding toward the waste ink tank 31 side in the thickness direction.
The front end engaging portion 43a of the first engaging lever portion 43 of the lever member 42, which extends between the pump cam gear 26 and the waste ink tank 31, engages with b in a disengageable manner. The lever member 42 is rotatably supported on a rotary shaft 42a in a direction orthogonal to the rotary shaft of the pump cam gear 26. Lever member 42 and locked portion 32b
The engagement thereof constitutes a prohibition means for prohibiting the rotation of the gear 26g against the above-mentioned urging force.

In addition to the first engaging lever portion 43, the lever member 42 extends in a direction substantially orthogonal to the first engaging lever portion 43 (that is, substantially in the moving direction of the carriage 6), and an engaging protrusion is provided at the tip. Second engaging lever portion 44 in which the portion 44a is formed
Also, each has a leaf spring portion 45 extending substantially in the same direction as the second engagement lever portion 44. The leaf spring portion 45 has a locking member 46 that is provided upright from the frame 5 near the tip thereof.
Therefore, the lever member 42 is always engaged in the direction in which the tip end engaging portion 43a of the first engaging lever portion 43 releasably engages with the locked portion 32b of the base plate portion 32 of the pump cam gear 26. It is urged to rotate.

A guide rod member 51 is arranged in the waste ink tank 31 so as to be parallel to the moving direction of the carriage 6, and a movable member for supporting the protective cap device 23, that is, a movable support member 52 is mounted on the guide rod member 51. Is supported so as to be slidable and rotatable. The movable support member 52 has an engaging protrusion 52a that is disengageably engaged with an engaged portion 6b formed on the carriage 6, whereby the engaging protrusion 52a is engaged with the engaged portion of the carriage 6. When engaged with 6b, the carriage 6 slides following the movement of the carriage 6. During this sliding movement, the movable support member 52 rotates toward the print head 4 side due to the engagement relationship between the guide convex portion 52b (FIG. 3) and the guide inclined surface 53a of the guide member 53, and the print head 4 moves. Nozzle surface protection cap device 23
Is covered by. In FIG. 5, the standby position P1 of the engagement protrusion 52a, the protective cap position P2,
The cam drive start position P3 is indicated by a chain line.

Further, the movable supporting member 52 has an engaging portion 52c (FIG. 5) which can be engaged with and disengaged from the engaging convex portion 44a of the second engaging lever portion 44, whereby the engaged portion of the carriage 6 is engaged. The movable support member 52 slides together with the carriage 6 from the protective cap position P2 to the outer cam drive position P3 due to the engagement relationship between the joint portion 6b and the engagement protrusion 52a of the movable support member 52, thereby engaging The portion 52c is engaged with the engaging protrusion 44a of the second engaging lever portion 44, and the lever member 42 is
By forcibly rotating it against the spring force of the leaf spring portion 45,
The engagement between the tip end engaging portion 43a of the first engaging lever portion 43 and the locked portion 32b of the base plate portion 32 of the pump cam gear 26 is released. Due to this disengagement, the pump cam gear 26 is engaged with the engaging protrusion 32a and the leaf spring 3.
Due to the engagement relationship with 3, the spring force of the leaf spring 33 causes it to rotate, and as a result, the gear 26g meshes with the drive gear 41 and makes one rotation. When moving from the position P2 to the position P3, the protective cap device 23 moves together with the print head 4 while covering the print head 4.
The second engagement lever portion 44 and the movable support member 52 constitute a releasing means for releasing the rotation prohibited state of the gear 26g.

After the printing operation is completed, the carriage 6 is
To position P2 to prevent the ink of the print head 44 from drying,
Further, based on the recovery operation instruction signal of the print head 4, the position P
3 can be selectively moved.

A coil spring 54 is interposed between the movable support member 52 and the waste ink tank 31, the movable support member 52 is returned to the standby position P1 and the protective cap device 23 is separated from the print head 4. Always urged in the direction.

With the above construction, when the carriage 6 moves from the printing area to enter the recovery area, the engaged projection 52 of the movable support member 52 is engaged with the engaged portion 6b of the carriage 6.
a is engaged, and the movable support member 52 is slid together with the carriage 6 in the engagement relationship. First, as described above, the protective cap device 23 covers the print head 4, and the print head 4 is moved to the position P3. . As a result, the engaging portion 52c of the movable support member 52 is moved to the second engaging lever portion 44.
Engages with the engaging protrusion 44a. As a result, the lever member 42
Is rotated against the spring force of the leaf spring portion 45, so that the rotation of the lever member 42 causes the tip end engaging portion 43a of the first engaging lever portion 43 and the substrate portion of the pump cam gear 26 to rotate. The engagement of the locked portion 32b of 32 is released.

By this disengagement, the pump cam gear 26
Is the engaging projection 32 of the base plate 32 of the pump cam gear 26.
Due to the engagement relationship between a and the leaf spring 33, the leaf spring 33 is rotated by the spring force, and as a result, the gear 26g meshes with the drive gear 41.

After the pump cam gear 26 starts rotating in this way, the carriage 6 moves to a position where the nozzle of a specific color of the print head 4 for which the recovery operation is instructed faces the suction cap 24. Then, the carriage 6 separates from the movable support member 52, and the protective cap device 2
3 disengages from the print head 4, but the pump cam gear 26 continues to rotate. The suction cap 24 is first advanced by the rotation of the pump cam gear 26, and comes into close contact with the nozzle. Then, the suction pump 25 is driven to suck the ink from the nozzle. After that, the suction cap 24 is retracted while the wiping device 21 is advanced, and the carriage 6 again moves the nozzle in a direction traversing the wiping device 21 to wipe the nozzle. Pump cam gear 2
When 6 rotates once, the leaf spring 33 again urges the engaging convex portion 32a and the first engaging lever portion 43 engages with the locked portion 32b, and then the drive gear 41 is notched. Recess 26
The pump cam gear 26 stops facing e.

When the carriage 6 moves again until the movable support member 52 moves to the position P3, the pump cam gear 26 starts rotating as described above, and the suction cap 24, the suction pump 25 and the wiping device 21 are driven. However, in this case, the carriage 6 moves the print head 4 to a position not related to the suction cap 24 or the wiping device 21. As a result, the suction pump 25 sucks (idle suction) the ink remaining in the suction cap 24 by the above-described suction operation. At this time,
The print head 4 is located, for example, in a flushing area outside the print area and the recovery area, and can perform flushing in which ink is ejected from all the ink ejection holes of the nozzle that has completed the recovery operation as described above.

When performing the recovery operation for the nozzles of a plurality of colors of the print head 4, the same operation as described above is repeated for the nozzles of each color.

Therefore, once the pump cam gear 26 starts rotating, the pump cam gear 26 makes one rotation regardless of the position of the carriage 6, and a series of operations are executed.
Even if the wiping device 21 or the like is not completely returned, the carriage 6 does not need to be present in the recovery area,
The next operation can be started by moving to the printing area (recording area) facing the printing paper or the flushing area. Particularly, in the case of rotating the pump cam gear 26 again in order to suck the ink remaining in the suction cap 24 as described above, the pump cam gear 26
Once the rotation starts, the carriage 6 can immediately move to another position as described above.

Further, the carriage 6 has a pump cam gear 26.
If the carriage 6 is not in the specific position requiring rotation, the paper can be fed even when the carriage 6 is in the recovery area, so that the printing paper 3 can be set in advance.

In the above embodiment, the carriage 6 rotates the lever member 42 via the movable supporting member 52, but the carriage 6 can be directly moved without using the movable supporting member 52 or the like. It is also possible to rotate the lever material that prohibits the rotation of the pump cam gear 26 to rotate the pump cam gear 26 that controls the operation of the recovery device RM.

Next, the protective cap device 23 will be described in detail. The protective cap device 23 includes the movable support member 5
2, a cap body 64 having a recess 65 for covering the nozzles of each print head 4, a cap holder 60 for supporting the cap body 64, a cap holder 60 and a movable support member 5.
It comprises two springs 62 and the like provided between the two. The cap body 64 is made of butyl rubber having a hardness of 40 degrees. Since butyl rubber has a low gas permeability, the ink drying prevention property is improved, and ink can be ejected well even when the cap is used for a long period of time.

The recess 65 of the cap body 64 is shown in FIG. In FIG. 6, only one recess 65 is shown. On the bottom surface 66 of the concave portion 65, a notch 67 formed by a sharp object is formed. The notch 67 is normally closed,
It opens when force is applied to the bottom surface 66. The notch 67 is designed to open with a force smaller than the force with which the meniscus is destroyed. For example, in the case of the print head 4 the meniscus is broken by the pressure change of 0.1 kg / cm ² is to open the incisions 67 in a pressure change of 0.08 kg / cm ² about two percent less than the breakdown pressure change of the meniscus To design.

Next, the opening / closing of the notch 67 will be described with reference to FIG. FIG. 7A shows a state when the cap body 64 covers the nozzle surface of the print head 4. From this point in time, when the ambient temperature rises, the air in the concave portion 65 expands and the pressure rises, and the bottom surface 66 exerts a force in the outward direction (downward direction in FIG. 7), as shown in FIG. 7B. As described above, the notch 67 is opened. After that, when the pressure inside the recess 65 becomes equal to the pressure outside, the notch 67 is closed as shown in FIG. When the ambient temperature becomes low, the recess 6
The air inside 5 contracts and the pressure decreases, and a force is applied to the bottom surface 66 inward (upward in FIG. 7) to open the notch 67, as shown in FIG. 7C. After that, when the pressure inside the recess 65 becomes equal to the pressure outside, the notch 67 is closed as shown in FIG. In this way, the cap body 6
In the state where 4 covers the nozzle surface of the print head 4,
By opening and closing the notch 67 due to a change in ambient temperature, destruction of the meniscus during non-recording is prevented,
Ink can be satisfactorily ejected from the start of recording.

A case where the cap main body 64 is brought into close contact with the print head 4 in a detached state will be described. When the cap body 64 is detached from the print head 4, the notch 67 is closed (see FIG. 7A). When the cap body 64 moves forward with respect to the nozzle surface of the print head 4 by the movement of the carriage 6, the cap body 64 first comes into contact with the nozzle surface. After that, the nozzle surface and the cap body 64 are further advanced so as to be in close contact with each other. At this time, the volume of the concave portion 65 becomes smaller than that at the time of contact, the pressure of the concave portion 65 becomes higher, the notch portion 67 opens (see FIG. 7B), and when the pressure of the concave portion 65 becomes equal to the atmosphere, the notch portion 67 closes.

The case where the cap body 64 is removed from the state in which the cap body 64 is in close contact with the print head 4 will be described. When the cap body 64 is in close contact with the print head 4, the notch 67 is closed (see FIG. 7A). And
When the cap body 64 is retracted with respect to the nozzle surface of the print head 4 by the movement of the carriage 6, the cap body 6
The nozzle 4 and the nozzle surface are brought into the contact state from the close contact state.
At this time, the volume of the recess 65 becomes larger than that at the time of the close contact, the pressure of the recess 65 becomes lower, the notch 67 opens (see FIG. 7C), and when the pressure of the recess 65 becomes equal to the atmosphere, the notch 67 closes. Subsequent cap body 64
The nozzle surface and the cap body 64 are separated from each other by the retreat. In this way, when the cap body 64 is attached to or detached from the print head 4, the notch 67 is opened and closed, whereby the meniscus of the print head 4 is prevented from being destroyed at the time of attachment or detachment, and good ink ejection can be performed. .

As described above, the notch 6 provided in the cap body 64 does not require a valve mechanism as in the prior art.
Since the meniscus can be prevented from being broken by opening / closing 7, the cost does not increase.

[0042]

As described above, according to the first aspect of the invention, in the ink ejecting apparatus having the ink jet head for ejecting the ink from the nozzle and the cap member for covering the nozzle when the ink jet head is not driven. The cap member is formed in the recess that forms a space by being in close contact with the inkjet head, an elastic body that forms at least a part of the recess, and the elastic body, and is normally closed. Since it has a notch that opens when a force is applied to it, the meniscus can be prevented from being destroyed without increasing the cost, and the ink can be prevented from drying at the nozzle even during long-term storage.

Further, in the ink ejecting apparatus of the second aspect, since the cut portion is opened before the ink meniscus at the nozzle is destroyed, it is possible to prevent the meniscus from being destroyed.

Further, in the ink ejecting apparatus of the third aspect, when the pressure of a predetermined value or more is applied to the elastic body, the cut portion opens, so that the meniscus can be prevented from being broken.

Further, in the ink ejecting apparatus according to the fourth aspect, when the cap member covers the ink jet head, the cut portion opens when the ambient temperature changes, so that the meniscus is not broken during non-recording. Ink is prevented, and ink can be ejected favorably from the start of recording.

Further, in the ink jet device according to the fifth aspect, since the elastic body forms the entire concave portion, the structure is simplified and the cost can be reduced.

Further, in the ink ejecting apparatus of the sixth aspect, since the elastic body is formed of butyl rubber having a low gas permeability, the ink drying prevention property is improved, and the ink is ejected even when the cap is worn for a long time. It can be done well.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing the overall configuration of an inkjet printer according to the present invention.

FIG. 2 is a schematic side view of the same.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV in FIG.

5 is a cross-sectional view taken along line VV of FIG.

FIG. 6 is a perspective view showing a cap body according to the present invention.

FIG. 7 is a diagram showing an opening / closing operation of a notch portion of the cap body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inkjet printer 4 Print head 6 Carriage 23 Protective cap device 51 Guide roller 52 Movable support member 53 Guide member 60 Cap holder 62 Spring 64 Cap body 65 Recess 66 Bottom surface 67 Notch

Claims (6)

[Claims] 1. An ink ejecting apparatus having an inkjet head that ejects ink from nozzles and a cap member that covers the nozzle when the inkjet head is not driven, wherein the cap member is in close contact with the inkjet head. A recess forming a space; an elastic body forming at least a part of the recess; and a notch formed in the elastic body, which is normally closed, and which opens when a force is applied to the elastic body. An ink jet device characterized by the above. 2. The ink ejecting apparatus according to claim 1, wherein the cutout portion is opened before the ink meniscus at the nozzle is destroyed. 3. The ink ejecting apparatus according to claim 2, wherein the cutout portion opens when a pressure of a predetermined value or more is applied to the elastic body. 4. The ink ejecting apparatus according to claim 2, wherein the cutout portion opens when the ambient temperature changes while the cap member covers the inkjet head. 5. The ink ejecting apparatus according to claim 1, wherein the elastic body forms the entire concave portion. 6. The ink ejecting apparatus according to claim 5, wherein the elastic body is made of butyl rubber.