JP2000117994A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recorder and a cleaning method for ink jet nozzle in which a print sheet can be protected against contamination and defective printing by removing ink from a nozzle forming face and a cap. SOLUTION: An ink jet nozzle is cleaned by covering the nozzle face 32 of an ink jet head 3 with a cap 55, discharging ink 84 from the nozzle face 32 of the ink jet head 3 through the cap 55, separating the cap 55 from the nozzle face 32 of the ink jet head 3, wiping the nozzle face 32 of the ink jet head 3, and covering the nozzle face 32 of the ink jet head 3 again with the cap 55.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an ink jet recording apparatus for printing on a printing sheet such as a cut sheet and a method for cleaning an ink jet nozzle. In particular, a carriage lock mechanism for locking a carriage on which a print head is mounted to a home position, an ink suction mechanism for sucking ink from ink nozzles of the print head, and a head wiping mechanism for wiping foreign substances adhered to the nozzle forming surface of the print head. The present invention relates to an ink jet recording apparatus and a method for cleaning an ink jet nozzle which can suitably perform drive control.

[0002]

2. Description of the Related Art Conventionally, as a recording apparatus incorporated in a POS (Point Of Sales) or a facsimile, etc.,
As a print head, there is a type in which a carriage on which an inkjet head is mounted reciprocates to print on a print sheet such as a cut sheet conveyed by a conveyance mechanism.

In an ink jet recording apparatus of this type, while a carriage on which a recording head is mounted is reciprocated within a predetermined range, ink droplets are ejected from ink nozzles of the recording head, thereby forming a desired recording medium on a recording medium. Form a print. At the time of non-printing, the carriage stands by at a home position outside the printing range. In the standby state, the nozzle forming surface of the recording head is covered with a cap so that the ink inside the ink nozzle dries and the viscosity does not increase, or air bubbles do not enter from the outside.

[0004] In addition, in order to recover a printing defect periodically or the like, the ink suction pump is driven in a state of being covered with a cap to suck ink from the ink nozzles of the recording head, thereby increasing the viscosity of the ink. Air bubbles are discharged to the outside. Further, the cap is removed, and foreign matters such as paper dust and ink adhered to the nozzle forming surface of the recording head are removed.
Wiping with an elastic blade (wiping). Then, the nozzle forming surface of the recording head is again covered with a cap (capping) to prevent an increase in viscosity due to drying of the ink and the intrusion of bubbles from the outside.

[0005]

However, according to the conventional ink jet recording apparatus, during capping after suction and wiping of the ink, the ink adhering to the cap is deposited on the nozzle forming surface of the recording head. There was a problem of sticking.

As a result, ink adheres to the cap seal portion of the nozzle forming surface of the recording head, and the adhered ink is transferred to the printing paper during printing, causing a problem that the printing paper becomes dirty. .

Another problem is that paper dust adheres to the ink adhering to the nozzle forming surface, and this paper dust may cause printing defects and the like. Further, there is a problem that as the cleaning operation is repeated, the amount of ink attached to the nozzle forming surface increases, and the ink leaks from the recording head or the carriage.

Therefore, an object of the present invention is to remove ink adhering to a joint portion between a nozzle forming surface and a nozzle forming surface of a cap, and to prevent printing paper stains due to ink transfer and printing defects due to paper dust. An object of the present invention is to provide an ink jet recording apparatus and a method for cleaning an ink jet nozzle which can prevent the ink jet recording.

[0009]

In order to solve the above-mentioned problems, an ink jet recording apparatus according to the present invention comprises: an ink jet head having nozzles for ejecting ink; capping means for covering a nozzle surface of the ink jet head with a cap; A discharge unit that discharges ink from the nozzle surface of the ink jet head via a cap, wherein the capping unit waits after the operation of the discharge unit with the cap removed from the nozzle surface, and a predetermined time has elapsed. Thereafter, a capping operation for covering the nozzle surface with the cap again is performed.

[0010] Thus, the open state of the cap is maintained for a predetermined period of time after the ink is discharged from the nozzle surface of the ink jet head, so that the ink adhering to the joint portion of the cap with the nozzle forming surface can be removed. It became so.

Further, the above-mentioned ink jet recording apparatus further comprises a cleaner means for wiping the nozzle surface of the ink jet head, and the cleaner means performs an operation of wiping the nozzle surface of the ink jet head while the capping means is on standby. It may be repeated one or more times.

[0012] Thus, the ink and paper dust adhered to the nozzle forming surface by the cleaner means are removed,
In order to maintain the open state of the cap for a predetermined time after wiping, it is also possible to remove ink that has adhered to the joint portion of the cap with the nozzle forming surface.

Further, in the above-mentioned ink jet recording apparatus, the discharge of the ink by the discharge means, the wiping operation of the cleaner means performed while the capping means is on standby, and
It is preferable to repeat the capping operation of the capping means a plurality of times.

Thus, in the cleaning operation,
The ink can be more completely removed.

Further, in the above-described ink jet recording apparatus, it is desirable that the standby time of the capping means is set to about 1 second to about 5 seconds.

Further, in order to solve the above-mentioned problems, the cleaning method of the present invention comprises: (A) covering the nozzle surface of the ink jet head with a cap; And
(C) A method of cleaning an inkjet head, in which the cap is separated from the nozzle surface of the inkjet head, and (D) the nozzle surface of the inkjet head is again covered with the cap. Step (D) includes the steps of: It is performed after a predetermined time has elapsed.

Thus, after the ink is discharged from the nozzle surface of the ink jet head, the open state of the cap is maintained for a predetermined time, so that the ink adhered to the joint portion of the cap with the nozzle forming surface can be removed. It became so.

In the above-described cleaning method, a step (E) of wiping the nozzle surface of the ink jet head may be performed between the step (C) and the step (D).

In this way, ink and paper dust attached to the nozzle forming surface are removed in the step (E) of wiping the nozzle surface, and the cap is kept open for a predetermined time after wiping. Ink that has adhered to the joint with the surface can also be removed.

In the above-described cleaning method, the steps (B) to (D) may be repeated a plurality of times. Further, the step (E) may be repeated before the operation of the step (D). It can be repeated several times.

Thus, in the cleaning operation,
The ink can be more completely removed.

In the above-described cleaning method, the predetermined time may be set to about 1 second to about 5 seconds.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ink jet recording apparatus and a method for cleaning an ink jet nozzle to which the present invention is applied will be described with reference to the drawings.

(Overall Configuration) FIG. 1 is a perspective view showing an ink jet recording apparatus to which the present invention is applied. FIG.
FIG. 2 is a perspective view when a main part of the recording apparatus shown in FIG. 1 is viewed from the opposite side.

As shown in these figures, the ink jet recording apparatus 1 comprises a recording head 3 for discharging ink droplets,
It has a carriage 2 on which the recording head 3 is mounted, a carriage moving mechanism 4 for moving the carriage 2 in the scanning direction indicated by the arrow A, and an ink supply mechanism 9 for supplying ink to the recording head 3.

The recording head 3 has a rectangular nozzle forming surface 32 on which a plurality of nozzles 31 for ejecting ink are formed. The nozzle forming surface 32 is exposed from a rectangular opening 30 formed on the carriage 2. are doing.

As shown in FIG. 2, the carriage moving mechanism 4 for moving the carriage 2 includes a guide shaft 45, a timing belt 41 bridged between a driving pulley 43 and a driven pulley 44, and a driving pulley. A carriage motor 42 for driving the rotation of the carriage 43 is provided. Carriage 2
Is supported slidably on the guide shaft 45 and is connected to the timing belt 41. Accordingly, when the timing belt 41 is rotated by the carriage motor 42, the carriage 2 moves in the scanning direction A along the guide shaft 45.

As described above, the ink supplied from the ink supply mechanism 9 is ejected from the nozzles 31 of the recording head 3 while moving the carriage 2 in the scanning direction A. The recording paper 14 is conveyed to a position facing the nozzle forming surface 32, and recording is performed on the surface of the recording paper 14 by ejected ink droplets.

The ink supply mechanism 9 includes an ink cartridge 91 that can be attached to and detached from an ink cartridge mounting portion 13 formed in the recording apparatus main body 12 of the ink jet recording apparatus 1, a pressure reducing device 98 mounted on the carriage 2, ,
It has an ink supply tube 95 connected between the ink cartridge 91 and the pressure attenuator 98.

The ink cartridge 91 has a configuration in which a portable ink bag 93 is housed inside a hard case 92. An ink supply needle 96 attached to one end of an ink supply tube 95 is connected to an ink outlet 94 formed in the ink bag 93. The other end 97 of the ink supply tube 95 is connected to a pressure attenuator 98. The leading end of the ink outflow path 99 formed in the pressure attenuator 98 is connected to the recording head 3. Therefore, the ink bag 9 of the ink cartridge 91
The ink stored in 3 is supplied to a pressure attenuator 98 via an ink supply tube 95, and is sent to the recording head 3 therefrom. In this way, the ink supplied to the recording head 3 is ejected from the ink nozzle 31.

Here, a head maintenance unit 5 is disposed at a position opposite to the home position of the carriage 2 indicated by the arrow C. The head maintenance unit 5 is an ink suction pump that constitutes an ink suction mechanism that sucks thickened ink, residual air bubbles, and the like from the ink nozzles 31 of the recording head 3 and discharges them to the outside when the carriage 2 moves to the home position C. 8 is provided. Further, the recording head 3 includes an elastic blade 53 that constitutes a head wiping mechanism for wiping foreign matters such as ink and paper dust adhered to the nozzle forming surface 32 of the recording head 3. Further, a lock lever 52 constituting a carriage lock mechanism for fixing the carriage 2 to the home position C is provided. The ink suction pump 8, the elastic blade 53, and the lock lever 52 are driven by a common drive mechanism 7 disposed in the unit case 50. Hereinafter, the ink suction pump 8, the elastic blade 53 and the lock lever 5
Structure 2 will be described.

(Ink suction pump) FIGS. 3A and 3B
FIG. 3 is a schematic diagram for explaining the internal structure and operation of the ink suction pump 8. As shown in this drawing, the ink suction pump 8 includes a cylindrical case 80 having a circular inner peripheral surface 80a, a flexible ink tube 81 arranged one round along the circular inner peripheral surface 80a, A pump cam rotor 82 and a circular inner peripheral surface 80 pushed by the cam rotor 82.
A roller 83 that rolls while crushing the ink tube 81 along the line a.

Rotation center L1 of pump cam rotor 82
Corresponds to the center of the circular inner peripheral surface 80a, and the outer peripheral surface thereof is formed with a small-diameter arc-shaped cam surface 82b covering a range of approximately 180 degrees.

The arc-shaped cam surface 82b has a rotation center L
The radius of curvature is set so that the radius of curvature gradually increases clockwise CW around 1. Also, step surfaces 82c, 82 connecting the remaining large-diameter outer peripheral surfaces to both ends of the cam surface 82b.
d is formed. The rotation shaft 83a of the roller 83 is pushed by the step surfaces 82c and 82d of the cam rotor 82, and can roll along the cam surface 82b.

One end 81a of the ink suction tube 81 is
The cap 5 drawn out of the case 80 and placed on the nozzle forming surface 32 of the recording head 3 when sucking ink.
5 is connected. The other end 81 of the ink suction tube 81
Similarly, b is drawn out from almost the same place of the case 80 to the outside, and is connected to the side of a waste ink tank (not shown).

The operation of the ink suction pump 8 having this configuration will be described. When the carriage 2 moves to the home position C, the cap 55 moves forward from the unit case 50 in conjunction with the movement, and covers the nozzle forming surface 32 of the recording head 3. In this state, the pump cam rotor 82
When the roller 83 rotates in the counterclockwise direction CCW, the roller 83 moves the ink tube 8 by the cam surface 82b of the cam rotor 82.
1 and is in a state where the ink tube 81 is crushed. In this state, the roller 83 is pressed in the circumferential direction by the step surface 82c of the cam rotor 82. As a result, the roller 83 rolls counterclockwise CCW while crushing the ink tube 81. As a result, the side of the ink tube 81 communicating with the cap 55 is in a negative pressure state, so that ink is sucked from the ink nozzles of the recording head 3.

Conversely, when the cam rotor 82 is rotated in the clockwise direction CW, the roller 83 is rotated by the cam surface 82b of the cam rotor.
Accordingly, the ink tube 81 that has been crushed by the rollers 83 returns to the original state. Next, as shown in FIG. 3 (B), the roller 83 is pushed by the other step surface 82d of the cam rotor 82 to rotate clockwise C.
Roll to W. In this case, the ink suction pump 8 does not perform the pumping action.

(Elastic Blade for Wiping Head) The elastic blade 53 can reciprocate between a forward position where it contacts the nozzle forming surface 32 of the recording head 3 and a retracted position where it does not contact the nozzle forming surface 32. . The elastic blade 53 has a rectangular shape with a certain thickness, and is held by a blade holding member 54.

When the carriage 2 moves from the printing area B to the home position C while the elastic blade 53 is held at the forward position, the tip of the elastic blade 53 contacts the nozzle forming surface 32 and Foreign matter, such as ink and paper powder, adhering to 32 is wiped off.

(Lock Lever) The lock lever 52, which is a component of the carriage lock mechanism, includes an elastic blade 53.
Swings in conjunction with the reciprocating movement of. Further, a carriage engaging end 52 movable to a lock position engaged with the lock lever engaging portions 26, 27 formed on the carriage 2 and an unlock position disengaged from the lock lever engaging portions 26, 27.
b. The lock lever 52 has an L shape as a whole, and its bent portion is rotatably supported by a swing center shaft 52 a attached to the unit case 50.

On the other hand, a pair of lock lever engaging portions 26 and 27 formed on the side of the carriage 2 are projections arranged at regular intervals in the carriage moving direction. The carriage engaging end 52b of the lock lever 52 can enter between the pair of lock lever engaging portions 26 and 27 by pivoting downward from above. The position of the lock lever 52 is a lock position where the movement of the carriage 2 is locked, and the other positions of the lock lever 52 are unlock positions.

Here, the cross-sectional shape of the carriage engaging end 52b of the lock lever 52 is such that one end in the swing direction is wide.

FIG. 4 is an explanatory diagram showing a carriage locked state by the lock lever 52. As shown in FIG.
The lock lever 52 has an L-shaped cross section, and has a wide upper end. For this reason, when the lock lever 52 swings from the upper side to the lower side as shown by the arrow in the figure and enters between the pair of lock lever engaging portions 26 and 27, the wide portion on the upper end side is one of It hits the engaging portion 27. As a result, the lock lever 52 is prevented from further swinging, and is held in a state sandwiched between the pair of engagement portions 26 and 27. This state can be released only when the lock lever 52 is swung upward.

(Driving Mechanism) Next, with reference to FIG. 5, the configuration of the driving mechanism 7 for driving the ink suction pump 8, the elastic blade 53 and the lock lever 52 having the above-described configuration will be described.

FIG. 5 is an exploded perspective view showing a main structure of a driving mechanism mounted on the recording apparatus of FIG. The driving mechanism 7 includes a single motor 51 and this motor 51.
And a power transmission mechanism 60 for transmitting the driving force of the above to the ink suction pump 8, the elastic blade 53 and the lock lever 52.

The power transmission mechanism 60 has a reduction gear train as a rotational movement transmitting mechanism for transmitting the rotational movement of the motor 51 to the ink suction pump 8. The gear train includes a pinion 71 attached to the output shaft of the motor 51, an idle gear 72 meshing with the pinion 71, and a pinion 7 integrally formed coaxially with the idle gear 72.
3 and a drive gear 74 meshed with the pinion 73.

The drive gear 74 is connected to the ink suction pump 8
The gear 74 and the cam rotor 82 are rotatably supported by a common rotation center shaft 61. The driving gear 74 and the engaging side surfaces of the cam rotor 82 are respectively provided at the same radial position at the same position in the radial direction.
a is formed. The driving gear 74 rotates, and the engagement projection 74a is engaged with the engagement projection 82a on the cam rotor 82 side.
After that, the cam rotor 82 rotates integrally with the drive gear 74.

The power transmission mechanism 6 of the drive mechanism 7 shown in FIG.
Reference numeral 0 includes a first conversion mechanism that converts the rotational motion transmitted through the gear train having the above-described configuration into a reciprocating motion of the elastic blade 53. The first conversion mechanism includes a rotary cam plate 7 rotatably supported by a common rotation center shaft 61.
Five. The rotary cam plate 75 is pressed against the drive gear 74 by the spring force of the coil spring 76 to be in a frictional engagement state.

An arc-shaped cam groove 75a is formed on the side surface of the rotary cam plate 75 over an angle range of about 90 degrees.
On the other hand, a reciprocating plate 77 is connected to the back side of the blade holder 54 holding the elastic blade 53, and a cam follower sliding in a circular cam groove 75a is provided at the rear end of the reciprocating plate 77. 77a is attached.

A pair of slide pins 77b and 77c protrude from the side surface of the reciprocating plate 77, and these slide pins 77b and 77c can slide along guide holes 50a and 50b formed in the unit case 50. It has become. Therefore, the reciprocating plate 77 can reciprocate back and forth within the range defined by the guide holes 50a and 50b, and the position moved to the front end of the guide holes 50a and 50b is the forward position of the elastic blade 53. Yes,
The position moved to the rear end of the guide holes 50a and 50b is the retreat position of the elastic blade 53.

In the first conversion mechanism having this structure, the rotary cam plate 75 frictionally coaxially engaged with the drive gear 74 is integrated with the drive gear 74 while the frictional engagement state is maintained. And rotate. By this rotation, the cam follower 77a of the reciprocating plate 77 slides along the cam groove 75a. The direction of movement of the reciprocating plate 77 is the guide hole 50a,
50b, the reciprocating plate 77
Reciprocates back and forth with the rotation of the cam groove 75a.

Further, the power transmission mechanism 60 is provided with a second conversion mechanism for converting the reciprocating motion of the reciprocating plate 77 obtained via the first converting mechanism into the swinging motion of the lock lever 52. This second conversion mechanism includes a reciprocating plate 77
A lock lever engaging pin 77d protruding from the side surface of the lock lever 52, a swing center shaft 52a swingably supporting a bent portion of the lock lever 52, and an engagement groove formed in a rear end portion of the lock lever 52. 52c. A lock lever engagement pin 77d is inserted into the engagement groove 52c with play.

In FIG. 5, when the reciprocating plate 77 moves back and forth, the lock lever 52 is moved to its swing center axis 52a.
Oscillating motion in the vertical direction within a predetermined angle range around.

(Ink Suction, Head Wiping, and Carriage Lock Operation) Next, ink suction, head wiping, and carriage locking operations in the cleaning mechanism of the ink jet recording apparatus of the present invention will be described. In the ink jet recording apparatus of the present invention, as shown in FIG. 1, a portion of the recording head 3 has a predetermined angle so that printing can be performed on both the roll sheet and the cut sheet 14.
For example, it is installed inclined at about 20 degrees.

FIGS. 6A to 6C are explanatory views showing the respective movement positions of the elastic blade 53 and the lock lever 52 during the cleaning operation. FIG. 7 is a sectional view of the recording head 3 and the cap 55 during the cleaning operation.
With reference to these figures, the operation of the ink suction pump 8, the elastic blade 53, and the lock lever 52, which are the cleaning mechanisms of the present invention, will be described. In addition, FIG.
FIG. 7C does not consider the inclination of the recording head 3 for the sake of simplicity.

As shown in FIG. 6A, at the time of normal printing, the lower end 7 of the cam groove 75a formed in the rotary cam plate 75 is used.
The cam follower 77a of the reciprocating plate 77 is located at 5b. In this state, the elastic blade 53 is at the retracted position, and the lock lever 52 is moved to its carriage engaging end 52b.
Is in an unlocked position retracted above the movement locus of the engagement portions 26 and 27 on the carriage side.

Next, when performing ink suction, after moving the carriage 2 to the home position C, the motor 51 is rotated counterclockwise CCW. The rotational force of the motor 51 is transmitted to the drive gear 74 via a gear train, and the rotary cam plate 75 frictionally engaged with the drive gear 74 also integrally rotates in the counterclockwise direction CCW. As a result, the reciprocating plate 77 is pushed forward along with the rotation of the cam groove 75a of the rotary cam plate.

When the rotary cam plate 75 rotates by approximately 45 degrees, the reciprocating plate 77 is pushed out to the intermediate position in the front-rear direction as shown in FIG. 6B. By this movement, the carriage engaging end 5 which is the front end of the lock lever 52 is moved.
2b swings downward to reach a lock position where it enters between the pair of engagement portions 26 and 27 on the carriage 2 side.

In this state, as shown in FIG. 4, the lock lever 52 cannot swing downward any more. As a result, the rotation of the rotary cam plate 75 is prevented, so that a slip occurs between the rotary cam plate 75 and the rotary cam plate 75 of the drive gear 74, and only the drive gear 74 continues to rotate. Therefore, the lock lever 52 is held at the carriage lock position regardless of whether the motor 51 is driven.

Thus, the carriage lock by the lock lever 52 is formed. In this carriage locked state, the side of the elastic blade 53 is located at an intermediate position of the movement, and has not advanced to a position where it can contact the nozzle forming surface 32 of the recording head.

Here, as shown in FIG. 7A, the nozzle forming surface 32 is capped with a cap 55, and the air suction port 55b provided in the cap 55 is closed with a valve 55c. When continuously rotated counterclockwise, the rotation is transmitted to the cam rotor 82 of the ink suction pump 8 via the drive gear 74, and the cam rotor 82
Rotates counterclockwise. As a result, as described with reference to FIG. 3, an ink suction operation is performed by the ink suction pump 8, and a predetermined amount of ink is sucked from the nozzle forming surface 32 of the recording head 3.

Next, as shown in FIG. 7B, after opening the valve 55c of the air suction port 55b, the ink suction operation is performed in the same manner as described above,
A predetermined amount of the ink 84 is sucked from the ink absorbing sponge 55a provided in the nozzle 5. At this time, since a capillary force acts on the joint surface between the nozzle forming surface 32 and the cap 55, a small amount of the ink 84 remains in this portion.

When the motor 51 is rotated in the clockwise direction CW after ink suction is completed, the reciprocating plate 77 is pulled backward by the reverse rotation of the rotary cam plate 75, contrary to the above operation. Accordingly, the tip of the lock lever 52 pivots upward, the carriage lock state is released, and the cap 55 is separated from the nozzle forming surface 32. At this time, FIG.
As shown in (C), the nozzle forming surface 32 and the cap 55
The ink 84 remaining on the joining surface of the nozzle formation surface 3
Separately adheres to the second side and the cap 55 side.

Next, in order to perform the wiping process by the elastic blade 53, the motor 51 is rotated counterclockwise CCW before the carriage 2 moves to the home position C. In this case, unlike the case of the above-described carriage lock, there are no engaging portions 26 and 27 for preventing the swing of the lock lever 52 halfway. Therefore, as shown in FIG. 6C, the elastic blade 53 moves forward to its front end position. When the carriage 2 is moved to the home position C in this state, as shown in FIG. 7D, the ink 84 and the paper dust adhered to the nozzle forming surface 32 of the recording head 3 are wiped off by the elastic blade 53. .

In this state, since the lock lever 52 is retracted downward, the carriage 2 can be reciprocated without being hindered by the lock lever 52. In this state, the forward movement of the reciprocating plate 77 is prevented by the guide holes 50a and 50b, and the rotating cam plate 75 is prevented.
And the drive gear 74 slips, and the elastic blade 53 is held at its front end position regardless of whether the motor 51 is driven. Next, in order to return the elastic blade 53 from this state to the original retracted state, the motor 51 is driven clockwise CW.

Here, the wiping operation shown in FIGS. 7C and 7D is generally performed in about 0.3 to about 0.4 seconds, so that even after the wiping is completed, the cap 55 is closed.
The ink 84 adheres to the connection surface between the nozzle 84 and the nozzle forming surface 32.

Therefore, as shown in FIG. 7E, the state in which the cap 55 and the nozzle forming surface 32 are kept separated is
Hold for a predetermined time, for example, about 1 to 5 seconds. As a result, the ink 84 flows down from the connection surface of the cap 55 with the nozzle forming surface 32, and this ink
Is absorbed by the sponge 55a provided at the bottom.

After the ink adhering to the nozzle forming surface 32 and the cap 55 is almost completely removed in this way, the nozzle forming surface 32 is covered with the cap 55 by the above-described capping operation.

As described above, in the ink jet recording apparatus 1 of the present invention, in the cleaning operation of the recording head 3, the ink and paper powder adhered to the nozzle forming surface 32 are removed by wiping, and the cap 55 is opened after wiping. In order to maintain the state for a predetermined period of time, it is possible to remove ink attached to the joint portion of the cap 55 with the nozzle forming surface 32.

The wiping by the elastic blade 53 may be repeated one or more times while the cap 55 is kept open. This makes it possible to more completely wipe the ink and paper dust from the nozzle forming surface 32.

Further, the operations shown in FIGS. 7B to 7E may be repeated a plurality of times. This makes it possible to more completely remove the ink adhering to the nozzle forming surface 32 and the cap 55.

[0072]

As described above, according to the ink jet recording apparatus and the ink jet nozzle cleaning method of the present invention, in the cleaning operation of the recording head, the ink and the paper powder adhered to the nozzle forming surface by the wiping are removed. In order to maintain the open state of the cap for a predetermined time after wiping, it is also possible to remove ink that has adhered to the joint portion of the cap with the nozzle forming surface.

As a result, the transfer of ink from the cap seal portion on the nozzle forming surface of the recording head to the printing paper does not stain the printing paper.

Even if the cleaning operation is repeated,
Since paper dust does not adhere to the nozzle forming surface, printing failure due to paper dust can be prevented.

Further, even if the cleaning operation is repeated, ink does not leak from the recording head or the carriage.

[Brief description of the drawings]

FIG. 1 is a perspective view of an ink jet recording apparatus to which the present invention is applied.

FIG. 2 is a perspective view showing a main part of the device shown in FIG.

FIGS. 3A and 3B are explanatory diagrams for explaining the internal structure and operation of an ink suction pump mounted on the apparatus of FIG. 1;

FIG. 4 is an explanatory diagram showing a carriage locked state by a lock lever in the recording apparatus of FIG. 1;

FIG. 5 is an exploded perspective view showing a main structure of a drive mechanism mounted on the recording apparatus of FIG. 1;

FIGS. 6A to 6C are explanatory diagrams for explaining the operation of the apparatus of FIG. 1;

FIG. 7 is a sectional view of a recording head and a cap during a cleaning operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink-jet recording apparatus 2 Carriage 3 Recording head 4 Carriage moving mechanism 5 Maintenance unit 7 Drive mechanism 8 Ink suction pump 31 Ink nozzle 32 Nozzle formation surface 50 Unit case 50a, 50b Engagement hole 51 Motor 52 Lock lever 52a Swing center axis 52c Engagement groove 52b Carriage engagement end 53 Elastic blade 55 Cap 55a Sponge 55b Air inlet 55c Valve 60 Power transmission mechanism 74 Drive gear 75 Rotating cam plate 75a Cam groove 77 Reciprocating plate 77a Cam follower 77b, 77c Slide pin 80a Circular inner circumference Surface 81 Ink tube 82 Cam rotor 83 Roller 84 Ink 85 Air

Claims (9)

[Claims] An ink jet head having a nozzle for ejecting ink; a capping means for covering a nozzle surface of the ink jet head with a cap; and a discharge means for discharging ink from the nozzle face of the ink jet head via the cap. In the ink jet recording apparatus, the capping unit waits in a state where the cap is removed from the nozzle surface after the operation of the discharge unit, and after a predetermined time elapses, a capping operation of covering the nozzle surface with the cap again. An inkjet recording apparatus. 2. The apparatus according to claim 1, further comprising a cleaner for wiping a nozzle surface of the inkjet head, wherein the cleaner repeats an operation of wiping a nozzle surface of the inkjet head one or more times while the capping unit is on standby. The ink jet recording apparatus according to claim 1, wherein: 3. The method according to claim 2, wherein the discharging of the ink by the discharging unit, the wiping operation of the cleaner unit performed while the capping unit is on standby, and the capping operation of the capping unit are repeated a plurality of times. 3. The ink jet recording apparatus according to 2. 4. The apparatus according to claim 1, wherein the standby time of the capping unit is about 1 second to about 5 seconds.
The inkjet recording apparatus according to any one of the preceding claims. 5. An ink jet head comprising: (A) covering a nozzle surface of an ink jet head with a cap; and (B) discharging ink from the nozzle surface of the ink jet head through the cap.
(C) A method of cleaning an inkjet head, wherein a cap is separated from a nozzle surface of the inkjet head, and (D) a nozzle surface of the inkjet head is covered with a cap again. A cleaning method which is performed after a predetermined time has elapsed after the operation. 6. The cleaning method according to claim 5, wherein a step (E) of wiping a nozzle surface of the inkjet head is performed between the step (C) and the step (D). 7. The cleaning method according to claim 5, wherein the steps (B) to (D) are repeated a plurality of times. 8. The cleaning method according to claim 6, wherein the step (E) is repeated a plurality of times before the operation of the step (D). 9. The cleaning method according to claim 5, wherein the predetermined time is about 1 second to about 5 seconds.