JP2528635B2 - Inkjet device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an inkjet device provided with a recovery device having a cleaning blade for preventing ink ejection failure and a suction means, and in particular, the displacement of the cleaning blade utilizing the action of a carriage. The present invention relates to an inkjet device having a configuration.

[Prior art]

An inkjet device supplies ink into an inkjet head, and drive elements (electrothermal transducers such as heating elements or electromechanical transducers such as piezo elements) corresponding to a plurality of ink ejection openings formed on the front surface of the inkjet head. ) Is driven based on the data signal to form a flying ink droplet from the ink discharge port toward the sheet (recording medium such as paper or plastic thin plate), and the ink droplet is attached to form (record) an image. It is a thing.

In this type of inkjet device, in order to prevent the ink ejection port from being clogged due to thickening or drying of the ink due to evaporation of the ink solvent, or dust adhesion or air bubble inclusion, ink ejection port capping or ink ejection is performed. A recovery device for sucking ink from the outlet or cleaning (wiping) the surface of the ink outlet is provided.

The recovery function of such a recovery device can be roughly classified into a cleaning function of the ink ejection port surface and an ink suction function of removing bubbles and thickened ink in the ink ejection port.

In the conventional ink jet device, the cleaning means for performing the cleaning function and the ink suction means for performing the ink suction function have separate and independent structures, so that the driving sources (stepping motor, etc.) are separately provided. However, there is a problem in that the number of parts is increased, the space for configuring the device is increased, and the cost and the size of the device are easily increased.

〔Purpose〕

The present invention has been made in view of such a conventional technique, and an object of the present invention is to move a cleaning unit that performs a cleaning function and an ink suction unit that performs an ink suction function to an operating position. It is an object of the present invention to provide an ink jet device that can be configured simply and compactly, can reduce the number of parts of a recovery device, can reduce the space, and can reduce the cost.

〔Overview〕

An inkjet device of the present invention is provided with a carriage for mounting and scanning an inkjet head provided with an ink ejection port, a cap for capping the ejection port, and the ejection port of the inkjet head. A cleaning blade for cleaning the discharge port surface, a moving means for independently moving the cleaning blade from the initial position to the cleanable position and moving the cap from the open position to the capping position, Locking means for locking the cleaning blade at the cleanable position,
When the lock is locked by the locking means, the carriage is scanned to clean the discharge port surface, and then abutment with a part of the carriage to release the locking by the locking means. The above object is achieved by having a configuration including: and a biasing unit for biasing the cleaning blade in a direction from the cleanable position toward the initial position.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic perspective view showing a main configuration of an embodiment of an ink jet device to which the present invention is applied.

In FIG. 1, a carriage 2 carrying a plurality of (four in the illustrated example) inkjet heads 1A, 1B, 1C, 1D is guided and supported by guide shafts 3, 3.

The driving force of the carriage motor 4 is transmitted to the carriage 2 via the timing belt 5, and the carriage 2 slides on the guide shafts 3 and 3 and moves along the platen 6. The carriage 2 scans reciprocally with the forward and reverse rotation of the motor 4.

In addition, a predetermined gap (for example, about 0.8 mm) is provided between the platen 6 (specifically, the sheet supported by the platen 6) and the front surface of the inkjet heads 1A to 1D on the carriage 2 (the surface on which the ink ejection ports are formed). ) Is provided.

A recording signal is output to the inkjet heads 1A to 1D through the flexible wiring 7 during scanning movement of the carriage 2.
The inkjet heads 1A to 1D are driven at a timing related to the position of the carriage 2 to eject ink, and the platen 6
Upper sheet (recording medium such as paper or plastic thin plate)
Record the image on.

During recording, dust paper dust adheres to the vicinity of the ink ejection ports of the inkjet heads 1A to 1D (for example, the dot forming means consisting of 24 orifices), or air is caught from the ink ejection ports. Ink ejection failure may occur.

In general, an inkjet device is provided with a recovery device RP for recovering this defective ink ejection.

In FIG. 1, when a recovery key (not shown) is operated to recover the defective ink ejection, the recording operation is interrupted and the carriage 2 moves toward the recovery device RP.

As the carriage 2 moves in the direction of the recovery device RP, the idle pulley 8, which supports the rotation of the timing belt 5 at one end, rotates. As the idle pulley 8 rotates, the deceleration planetary gear group 9 provided coaxially therewith also rotates.

When the carriage 2 moves to a predetermined position in the direction of the recovery device RP, the lever 10 engaged with the cam groove of the final stage gear (not shown) of the planetary gear group 9 moves in the direction of arrow A around the shaft 11 in the direction of arrow A. Rotate by the amount determined by.

When the lever 10 rotates in the direction of arrow A, the stay 12 engaged with the tip of the lever 10 slides in the direction of arrow B,
The plate 13 fixed to the stay 12 also moves in the direction of arrow B.

This plate 13 is engaged with the circumferential groove 15 of the ratchet gear 14, and the ratchet gear 14 is free to rotate but axially
It moves with 13.

Therefore, when the plate 13 moves in the direction of the arrow B, the ratchet gear 14 is switched from the state in which it meshes with the ratchet gear 16 to the state in which it meshes with the ratchet gear 17.

By this switching, the rotation of the sheet feeding motor (hereinafter referred to as LF motor) 18 is changed to the LF motor gear 19 and the idle gear 20.
Then, the state is transmitted to the ratchet gear 17 via the ratchet gear 14.

The ratchet gear 17 is integrally formed with a gear portion, and this gear portion meshes with the dowel gear 21.
This doweled gear 21 is the input gear of the recovery device RP, and therefore, by switching in the direction of arrow B, the LF motor
At 18, the recovery device RP is driven.

FIG. 2 is a rear view taken along the line II-II in FIG.
3 is a front view of the carriage 2 taken along the line III-III in FIG. 1, FIG. 4 is a schematic structural view of the recovery device RP in FIG. 1, and FIG. 6 is a plan view of the recovery device RP in the figure, FIG. 6 is a front view seen from the line VI-VI in FIG. 5, and FIG. 7 is a left side seen from the line VII-VII in FIG. Fig. 8 is a plan view, Fig. 8 is a central longitudinal sectional view of the recovery device of Fig. 5, Fig. 9 and Fig. 10 are transverse sectional views at different levels of Fig. 5, respectively, and Fig. 11 is 6 is a timing chart illustrating an operation sequence of a recovery device for an inkjet device according to the present invention.

In FIG. 1, the position of the carriage 2 is controlled with reference to the home position detected by a home position sensor (not shown) installed on the left side portion.

When the recovery key is operated as described above, the carriage 2 moves to a position where the inkjet heads 1A to 1D face the corresponding rubber caps 22A, 22B, 22C and 22D.
In this position, the LF motor 18 is in the recovery device as described above.
It has been switched to the RP drive side and therefore a recovery operation is performed.

First, the wiping means for cleaning the ejection port surface (the surface on which the ejection ports are formed) of the inkjet heads 1A to 1D will be described. This wiping means is a cleaning blade
24 is configured to wipe off the discharge port surface.

When the LF (line fade) motor 18 rotates, the dowel with a dowel 21 rotates, and the dowel 23 has a cleaning blade 24.
The cleaning blade 24 engages with the rear end portion 25 and projects toward the carriage 2 against a return spring (71 in FIG. 7) that biases toward the LF motor 18.

FIG. 2 shows an engaging portion between the dowel-equipped gear 21 and the cleaning blade 24.

The gear 21 with the dowel is changed from the initial state of FIG.
The LF motor 18 is stopped when the cleaning blade 23 rotates to a position where it presses the rear end portion 25 of the cleaning blade 24 to displace it.

The rotation of the LF motor 18 causes the rotation cam 26 (FIG. 4) of the recovery device RP that rotates at the final deceleration to rotate at the same time.

Therefore, the cap housing 27 supporting the rubber caps 22A to 22D tries to move in the direction of the inkjet heads 1A to 1D, but the gear 21 with the dowel and the LF motor 18 of the rotary cam (cam disk) 26 are operated. Since the reduction gear ratios are largely different, the movement of the cap housing 27 can be ignored, the gaps between the caps 22A to 22D and the inkjet heads 1A to 1D hardly change, and both do not come into contact with each other.

In FIG. 7, when the cleaning blade 24 forming the wiping means is projected by the rotation of the dowel with a dowel 21, the claw 28 of the cleaning blade 24 pushes down the claw 30 of the holding lever 29 pivotally attached to the lower side thereof. It works to get over nail 30.

Therefore, the holding lever 29 is rotated in the counterclockwise direction against the return spring 72 to stop the lever shaft 31, and the holding lever 29 is rotated in the clockwise direction after the pawl 28 of the cleaning blade 24 has passed. Cleaning blade 24
The claw 28 is caught on the front side of the claw 30 of the holding lever 29, and the cleaning blade 24 is held in the protruding position.

With the cleaning blade 24 protruding, move the carriage 2 in the direction of the platen 6 (to the right in FIG. 1),
The blade 32 attached to the tip of the cleaning blade 24 wipes the ejection port surface of the inkjet heads 1A to 1D.

When the carriage 2 is moved from left to right in this way, the reset claw 33 (FIG. 3) of the carriage 2 becomes the tip claw of the holding lever 29.
34, the holding lever 29 is pushed down counterclockwise in FIG. 1, and the claw 28 of the cleaning blade 24 and the holding lever are engaged.
The engagement of 29 with the claw 30 is temporarily released.

Therefore, the cleaning blade 24 tries to retreat in the direction away from the inkjet heads 1A to 1D by the action of the return spring 71, but in that case, the cleaning blade 24
Since the backward movement is blocked by the doweled gear 21, the cleaning blade 24 is held in a protruding state even when the reset claw 33 of the carriage 2 passes.

While the carriage 2 moves further to the right, the ejection port surface of the inkjet heads 1A to 1D is wiped off (wiping).
Is done.

In that case, before the rotational force of the LF motor 18 is switched to the driving side of the Latin 6 by the movement of the carriage 2, and the pawl 30 of the holding lever 29 is a pair of reset pawls 33, 35 of the carriage 2 (see FIG. 3). ), The LF motor 18 is switched to the reverse rotation (reverse rotation) of the forward rotation (forward rotation) at the time of the recovery operation and is rotated to the initial position. The state shown in FIG. 1 is restored.

LF in the ink suction operation (sequence) described later
Due to the reverse rotation of the motor 18, the dowel-equipped gear 21 rotates one or more revolutions in the reverse direction.
Passes through the clearance groove 49 (FIG. 2) of the rear end portion 25 of the cleaning blade 24, and gradually the cleaning blade 24
Is lifted in the direction of arrow C (Fig. 2) against the spring 50 (Fig. 2) and returned to its original position. Therefore, the cleaning blade 24 does not project to the ink ejection port side.

When cleaning of all the ejection opening surfaces of the inkjet heads 1A to 1D is completed while the carriage 2 is moving from left to right, the reset claw 35 (Fig. 3) of the carriage 2 is engaged with the tip claw 34 of the holding lever 29. To do. This allows the cleaning blade
The locking state of 24 is released, and the cleaning blade 24 is reset to the initial position (retracted position in FIG. 1) by the urging force of the return spring 71 (FIG. 7), and the ejection port surface is cleaned (wiping). The operation ends.

The cleaning operation by the wiping unit as described above can be executed plural times by reciprocating the carriage 2.

By this cleaning operation (wiping operation), dust, paper dust, thickened ink, etc. adhering to the ejection port surface can be reliably removed.

The recovery operation by ink suction from the next ejection port will be described.

FIG. 11 is a timing chart illustrating an operation sequence of the recovery device RP of the inkjet device of FIG.

When the above-mentioned cleaning (cleaning or wiping) of the ejection port surface is completed, the carriage 2 is set to the inkjet head.
1A to 1D move from right to left to the position facing the respective caps 22A to 22D, and stop at that position.

 After the carriage 2 is stopped, the LF motor 18 is rotated forward.

When this forward rotation continues, the rotational force of the dowel with gear 21 is transmitted to the shaft 36 (Fig. 5) of the dowel, which causes the pulley 37 (Fig. 5) that rotates integrally with the shaft to rotate, and the timing belt (not shown). The pulley 38 is rotated via the (illustrated), and the worm 39 (FIG. 4) rotating coaxially with the pulley 38 is rotated.

In FIG. 4, the weave 39 meshes with the worm wheel 40. A plurality of rectangular grooves 41 are formed on the shaft integral with the worm wheel 40, and as the worm wheel 40 rotates, the rotary cam 26 coaxial with the worm wheel 40 fits into the rectangular groove 41 and rotates at the same speed.

When the LF motor 18 continues to rotate, the embossment 42 (No. 9) of the cap housing 27 (FIG. 1) is inserted into the cam groove (not shown) of the rotary cam 26.
(Fig.) Is engaged, the cap housing 27 is moved in the direction of the inkjet heads 1A to 1D, and the rubber caps 22A to 22D are brought into close contact with the respective ejection port surfaces, and the capping state (capping closed) is achieved.

In FIG. 4, each rubber cap 22A to 22D has a conduit 4
3, 44 are connected, the conduit 43 is connected to the vent hole 45, and the conduit 44 is connected to the pump 46.

When the capping state is reached, as shown in the timing chart of the ink suction operation of FIG. 11, the ventilation valve 47 is in the open state, the ventilation cam 45 is in the atmospheric state, and the rubber caps 22A to 22D are deformed so that the inside 22A of the rubber cap 22A. Even if the volume inside the rubber cap 48 is compressed by the deformation of ~ 22D, the meniscus of the ejection ports of the inkjet heads 1A ~ 1D does not recede.

In FIG. 4, when the forward rotation of the LF motor 18 continues, the circumferential protrusion 51 (FIG. 10) of the cam disk is rotated along with the rotation of the rotary cam 26.
Pushes the ventilation valve support 52 in the direction of arrow D (FIG. 4), and the ventilation valve 47 closes the ventilation hole 47 (closes the ventilation valve). This closing of the ventilation valve corresponds to the point S2 in FIG.

When the rotation of the worm wheel 40 (FIG. 4) is continued with the capping closed and the ventilation valve closed, a plurality of wheel cams 53 (FIG. 4) are formed at positions of different radial lengths in the radial direction of the worm wheel 40. The plurality of wheel cams 53 engage with cams having the same diameter on the housing side of the recovery device RP, and the worm wheel 40 moves downward.

At this time, since the shaft of the worm wheel 40 is fitted in the rotary cam (cam disc) 26 and the rectangular groove 41, the worm wheel 40 moves downward while rotating the rotary cam 26.

In FIG. 4, by moving the worm wheel 40,
The piston 55 of the pump 46 is pushed down via the steel ball 54. The steel balls 54 are for not transmitting the rotation of the worm wheel 40 to the piston 55.

When the piston 55 is pushed down, the inside of the cylinder 56 of the pump 46 becomes negative pressure, and the ink is sucked from the ejection port via the conduit 44.

The downward movement speed of the worm wheel 40 depends on the LF motor 18
The rotation speed can be controlled by the worm wheel 40
By considering the moving speed of the ink and the inflow amount of ink due to the negative pressure in the cylinder 56, it is possible to set the ink suction from the ejection port with a predetermined negative pressure and prevent the generation of dissolved air dissolved in the ink. You can

In FIGS. 4 and 11, when the worm wheel 40 has moved to the lowermost end (point S3 in FIG. 11) and continues to rotate in this lower end state, the circumferential projection 51 of the rotary cam (cam disc) 26 is rotated.
(FIG. 10) has passed the ventilation valve support 52 (FIGS. 4, 10) and the ventilation valve 47 (FIG. 4) allows the vent hole 45 to communicate with the atmosphere (vent valve open, FIG. 11). Corresponding to S4 point in).

By controlling the rotation speed of the worm wheel 40 in the lower end state, it is possible to control the time required for the air hole 45 to communicate with the atmosphere.

In FIG. 4, the inside of the cylinder 56 is in a negative pressure state and the vent hole is formed.
When 45 communicates with the atmosphere, the sucked ink in the rubber cap inside 48 flows into the cylinder 56 through the conduit 44 together with the air flowing in from the conduit 43, and the ink remaining amount in the rubber cap inside 48 decreases.

The degree of negative pressure inside the cylinder 56 when the vent hole 45 communicates with the atmosphere needs to be controlled by the rotation speed of the worm wheel 40 so that the meniscus of the discharge port does not recede.

The reason is that before the vent hole 45 communicates with the atmosphere, ink is being sucked from the ejection port and the sub-tank 58 at the rear of the ejection port
This is because the air layer 59 in FIG. 4 has a negative pressure, but when the vent hole 45 communicates with the atmosphere, the inside of the rubber cap 48 immediately becomes atmospheric pressure and the ink meniscus at the discharge port is retracted. In addition, it is necessary to control the rotation speed of the worm wheel 40.

In FIG. 4, when the ventilation valve 47 is opened and the worm wheel 40 continues to rotate, the worm wheel 40 follows the shape of the wheel cam 53, and the piston return spring 60 causes the worm wheel 40 to move to the lowermost end via the piston 55 and the steel ball 54. Returns to the top end (initial state). This time point corresponds to the point S5 in FIG.

In addition, when the piston 55 returns, the ink sucked into the cylinder 56 is discharged by the one-way valve 61 attached to the piston.
Exhausted through.

The rotational position of the worm wheel 40 is set to S5 and
At the time of coming during S6, the forward rotation of the worm wheel is switched to reverse rotation, and the ventilation valve 47 is opened (point S4 in FIG. 11).
By rotating until before and sucking air (empty suction) through the conduit 43, it is possible to reliably discharge the ink remaining in the rubber cap inside 48 during the above-described ink suction. If the number of times of the empty suction is repeated, a further effect can be obtained.

In the above description, the forward rotation worm wheel 40
When changing from the S3 state (moving to the bottom end) to the S4 state where the ventilation valve is open, it is necessary to control the rotation speed of the worm wheel 40 so that the meniscus of the discharge port does not retreat to a negative pressure. The control of this portion can also be performed by the following method.

That is, the rotation of the worm wheel 40 is stopped until the S3 state and the S4 state (see FIG. 11), and the air layer 59 of the sub tank 58 is stopped.
If the pressure is reliably brought to the atmospheric pressure state and then the sequence proceeds to the next sequence, the meniscus of the discharge port does not recede.

After the above-mentioned empty suction is completed, the worm wheel 40
The forward rotation continues from the point between point S6 and point S6, and the circumferential projection 51 (Fig. 10) of the rotary cam (cam disk) 26 similarly pushes the ventilation valve support 52 in the direction of arrow D to open the ventilation valve.
Close 47 (S7 point in Fig. 11).

At this time, since the vent hole 45 is closed by the flat part of the vent valve 47, the volume does not change at this part, and the meniscus of the discharge port does not recede even in the capping closed state.

After passing the ventilation valve 47 closed (S7 point in Fig. 11),
Vent valve 47 is opened from the rear end (S10 in FIG. 11) through the capping open (S9 in FIG. 11) from the rear end of capping (S8 in FIG. 11). (First
It moves to S11 point in Fig. 1), and after that, it ends (same as the initial state), that is, S12 point in Fig. 11 (same as S0 point).
Then, a series of operations is completed.

The printing failure can be prevented by executing the recovery operation described above. However, as a more reliable recovery operation, the following sequence may be added between the points S7 and S12.

Hereinafter, the operation from the S7 point to the S12 point to be added will be described.

As described above, one cause of defective printing is the inclusion of air from the ejection port or the accumulation of air in the vicinity of the ejection port and the ink passage to the ejection port.

As described above, the removal of the air is almost completely recovered by the ink suction operation from the ejection port, but very rarely, the ink supply pipe 62 to the ejection port portion of the inkjet heads 1A to 1D (see FIG. 4). ) Or air adheres to the filter 63 in the ink supply pipe 62 in a bubble state, and the air cannot be completely removed only by the above-described ink suction sequence,
Ink droplets may generate splashes or satellites during recording.

In order to remove and recover this, first rotate the worm wheel 40 backward from the initial position S0 (or S12 point) of the recovery operation sequence between the ventilation valve 47 (S7 point) and the rear end of the capping closure (S8 point). , Switch from that position to forward rotation and return to the initial position S0 point (S12 point).

By repeating this operation multiple times, the rubber cap
When 22A to 22D put the discharge port in the capping state, the pressure inside the rubber cap 48, which is in the sealed state, increases, and air is forcedly sent from the discharge port. By sending the air in this way, the attached air in the bubble state is removed.

After the above operation is completed, if the ink suction sequence at points S0 to S12 described above is performed, defective ink ejection can be more completely removed.

〔effect〕

As is clear from the above description, according to the inkjet device of the present invention, a carriage for mounting and scanning an inkjet head provided with an ink ejection port,
A cap for capping the ejection port, a cleaning blade for cleaning the ejection port surface of the inkjet head provided with the ejection port,
Moving means for independently moving the cleaning blade from the initial position to the cleaning position and moving the cap from the open position to the capping position, and locking the cleaning blade at the cleaning position. And a locking means for locking the locking means for scanning the carriage while the locking means is engaged to clean the discharge port surface and abut on a part of the carriage. And a urging means for urging the cleaning blade in the direction from the cleanable position to the initial position. Cleaning means for performing a cleaning function and ink for performing an ink suction function without requiring a special drive source Can configure the moving means for moving the operating position the pull tab stage simplicity and compact, reducing the number of parts of the recovery device, an ink jet apparatus is provided which can reduce the size and cost of the space.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing the structure of a main part of an embodiment of an ink jet device to which the present invention is applied, FIG. 2 is a rear view taken along line II-II in FIG. 1, and FIG. Line III-III in Fig. 1
4 is a front view of the carriage seen from above, FIG. 4 is a schematic structural view of the recovery device in FIG. 1, FIG. 5 is a plan view of the recovery device in FIG. 1, and FIG. 6 is a line in FIG. VI-VI front view, No. 7
5 is a left side view taken along the line VII-VII in FIG. 5, FIG. 8 is a central longitudinal sectional view of the recovery device of FIG. 5, and FIG. 9 is a transverse sectional view of the recovery device of FIG. 10 is a cross-sectional view of the recovery device of FIG. 5 at a level different from that of FIG. 9, and FIG. 11 is a timing chart illustrating the operation sequence of the recovery device of the inkjet device according to the present invention. 1A-1D …… Inkjet head, 2 …… Carriage, 6
...... Platen, 14, 16, 17 …… Ratchet gear, 18 ……
Motor, 21 ... Gear with dowel, 22A-22D ... Cap,
24 …… cleaning blade, 28 …… claw, 29 …… holding lever, 30 …… claw, 32 …… blade, 33, 35 …… reset claw, 34 …… tip claw, 46 …… suction pump, 48 …… Ventilation valve, 48 ... inside cap, RP ... recovery device.

Claims (5)

(57) [Claims] 1. A carriage for mounting and scanning an ink jet head provided with an ink ejection port, a cap for capping the ejection port, and an ejection port provided with the ejection port of the ink jet head. A cleaning blade for cleaning the surface; moving means for independently moving the cleaning blade from the initial position to the cleanable position and moving the cap from the open position to the capping position; Locking means for locking the cleaning blade at a possible position, and a part of the carriage when the discharge surface is cleaned by scanning the carriage when the locking means is engaged. Release means for abutting and releasing the locking by the locking means, Jet apparatus characterized by a cleanable position having a biasing means for biasing said cleaning blade in the direction toward the initial position. 2. The ink jet device according to claim 1, wherein a reset claw is provided as a part of the carriage. 3. The ink jet apparatus according to claim 1, wherein the ink jet head has a drive element that generates energy used to eject ink from the ejection port. 4. The ink jet apparatus according to claim 3, wherein the drive element is a heating element. 5. The ink jet apparatus according to claim 3, wherein the drive element is a piezo element.