JPS62238751A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To reduce the number of parts for a recovery device, minimize space and reduce cost by allowing a cleaning blade to protrude when a motor for actuating the sequential operation of an ink suction means rotates in one direction and the cleaning blade to stop at a retreating position when the motor is reversed. CONSTITUTION:When a line feed motor 1 rotates, a gear with a dowel 21 turns and the dowel is fitted to the rear end 25 of a cleaning blade 24, which is, in turn, enabled to protrude in the direction of a carriage 2. A claw 28 pushes down the claw 30 of a holding lever 29 which, in turn, retains the cleaning blade 24 at a protruded position. The carriage 2 is moved in the direction of a platen 6 and a blade 32 attached to the tip of the cleaning blade 24 is caused to wipe off the ink discharge outlet surface of a recording head 1A-1D. While the claw 30 is positioned between a pair of resetting claws 33, 35, the motor 18 is reversed to return the gear 21 with a dowel to an initial condition.

Description

Detailed Description of the Invention [Technical Field] The present invention prevents clogging and ink drying of the ink ejection ports of a recording head in an inkjet recording device, and also prevents ink ejection port defects by wiping the ink ejection port surface. The present invention relates to an improvement in a recovery device for preventing

[Prior art]

An inkjet recording device supplies ink into a recording head, and drives elements (electrothermal transducers such as heating elements or electromechanical transducers such as piezo elements) that correspond to a plurality of ink ejection ports formed on the front surface of the recording head. The recording medium is driven based on data signals to form flying ink droplets from ink ejection ports toward a sheet (a recording medium such as paper or a thin plastic plate), and these ink droplets are attached to record.

In this type of inkjet recording device, ink ejection ports are capped to prevent ink ejection ports from becoming clogged due to ink thickening or ink drying due to evaporation of ink solvent, or from dust adhesion or air bubbles. A recovery device is provided which performs suction of ink from the ink ejection port or cleaning (wiping) of the ink ejection port surface.

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

In conventional inkjet recording apparatuses, the cleaning means for performing the cleaning function and the ink suction means for performing the ink suction function are each configured independently. etc)
The problem is that the number of parts increases, the space for the device configuration increases, and the cost amplifier and recording device tend to increase in size.

〔the purpose〕

An object of the present invention is to solve the problems of the prior art, and to reduce the number of parts in the recovery device by driving the cleaning means using the movement of the ink suction system and centrifuging the cleaning means by the movement of the carriage. reduction of
An object of the present invention is to provide an inkjet recording device that can reduce space and cost.

〔overview〕

The present invention provides a recovery device including an ink suction means having a cap that covers an ink discharge port, a ventilation valve that opens and closes the inside of the cap to the atmosphere, and a suction pump that generates negative pressure in the cap, and wiping means having a cleaning blade that moves forward and backward; the cleaning blade protrudes when a motor that performs a sequence operation of the ink suction means rotates in one direction;
The above object is achieved by configuring the cleaning blade to remain in the retracted position when the motor rotates in the opposite direction.

〔Example〕

The present invention will be specifically described below with reference to the drawings.

FIG. 1 shows the main structure of an inkjet recording apparatus according to an embodiment of the present invention.

In FIG. 1, a carriage 2 on which a plurality of (four in the illustrated example) recording heads IA, IB, IC, 10 are mounted is guided and supported by a guide shaft 3.3.

The driving force of the carriage motor 4 is transmitted via the timing belt 5 to the carriage 2, which slides on a guide shaft 3.3 and moves along the platen 6. The carriage 2 reciprocates as the motor 4 rotates forward and backward. Further, a predetermined gap (for example, 0.5 mm is provided between the front surface of the recording pads IA to ID on the carriage 2 (the recording surface on which ink ejection ports are formed) and the platen 6 (more specifically, the sheet supported by the platen). There are approximately 8 dragons).

During the scanning movement of the carriage 2, a recording signal is output to the recording pads IA to ID via the flexible wiring 7, and the recording pads IA to I are outputted to the recording pads IA to ID at a timing related to the position of the carriage 2.
D is driven to eject ink and print the sheet on the platen 6 (
Record on recording media (such as paper or thin plastic plates).

During recording, dust or paper scraps may adhere to the vicinity of the ink ejection ports (for example, dot forming means consisting of 24 orifices) of the recording rads IA to ID, or air may be trapped from the ink ejection ports. , ink ejection failure may occur.

Generally, in an inkjet recording apparatus, a recovery device RP is installed to recover from this ink ejection failure.

When a recovery key (not shown) is operated to recover from the ink ejection failure, 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 force, the idle pulley 8, which supports the rotation of the timing belt 5 at one end, rotates. As the idle boob IJ 8 rotates, a planetary gear group 9 for deceleration provided coaxially with the idle boob IJ 8 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 gear (not shown) of the planetary gear group 9 moves the cam in the direction of arrow A around the shaft 11. It rotates by an amount determined by the groove.

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, and the plate 13 fixed to the stay 12 also moves in the direction of arrow B.

This plate 13 engages in a circumferential groove 15 of a ratchet gear 14, so that the ratchet gear 14 is free to rotate but moves together with the plate 13 in the axial direction.

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

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

A gear portion is integrally formed on the ratchet gear 17, and this gear portion meshes with the gear 21 with a dowel. This doweled gear 21 is the input gear of the recovery device RP, and therefore, by switching in the direction of the arrow B mentioned above, the L
The recovery device RP is now driven by the F motor 18.

The position of the carriage 2 is controlled based on a home position detected by a home position sensor (not shown) installed at the left end.

When the recovery key is operated as described above, the carriage 2 returns to the rubber camp 22 corresponding to each of the recording heads IA to ID.
A, 22B, 22C, and 22D. In this position, as described above, <LF motor 18
has been switched to the recovery device RP drive side, and therefore a recovery operation is performed.

First, a wiping means for cleaning the recording surfaces (surfaces on which ink ejection ports are formed) of the recording rads IA to ID will be described. This wiping means is the cleaning blade 24.
The device is configured to wipe the ink ejection orifice surface with the wiper.

When the LF (line feed) motor 18 rotates, the gear 21 with a dowel rotates, and the dowel 23 engages with the rear end 25 of the cleaning blade 24, and the cleaning blade is driven by a return spring ( (not shown) in the direction of the carriage 2.

Figure 2 shows the gear 21 with dowels and the cleaning blade 24.
The engaging part is shown.

When the dowel gear 21 rotates from the initial state shown in FIG. 1 to a position where the dowel 23 presses and displaces the rear end 25 of the cleaning blade 24, the LF motor 18 is stopped.

FIG. 3 shows the front of the carriage 2 as seen from the line ``--'' in FIG. 1, and FIG. 4 shows a schematic overall arrangement of the recovery device RP.

Incidentally, due to the rotation of the LF motor 18 described above, the rotating cam 26 (FIG. 4) of the recovery device RP, which rotates at the final deceleration, also rotates at the same time.

For this reason, the cap housing 27 supporting the rubber caps 22A to 22D tries to move in the direction of the recording heads IA to ID, but the doweled gear 21 and the rotating cam (cam disc) 26 from the LF motor 18 Since the reduction ratios are greatly different, the movement of the camps 27 can be ignored, and the gaps between the caps 22A to 22D and the recording heads IA to ID hardly change, and the two do not come into contact with each other.

When the cleaning blade 24 constituting the wiping means protrudes due to the rotation of the doweled gear 21, the claw 28 of the cleaning blade moves to push down and overcome the claw 30 of the holding lever 29 pivotally attached to the lower side thereof.

Therefore, the holding lever 29 is rotated counterclockwise about the lever shaft 31 against the return spring (not shown), and the claw 28 of the cleaning blade 24 is rotated counterclockwise around the lever shaft 31.
The cleaning blade 24 is caught in the claw 30 of the cleaning blade 24, and the cleaning blade 24 is held in the protruding position.

With the cleaning blade 24 protruding, the carriage 2 is moved toward the platen 6 (rightward in FIG. 1), and the blade 32 attached to the tip of the cleaning blade 24 cleans the ink ejection ports of the recording heads IA to ID. The surface is wiped.

When carriage 2 moves from left to right in this way, carriage 2
The reset pawl 33 (FIG. 3) engages with the tip pawl 34 of the holding lever 29, and the holding lever 29 is pushed down in the counterclockwise direction in FIG. The engagement with the device is temporarily released.

For this reason, the cleaning blade 24 tries to retreat in the direction away from the recording heads IA to ID by the action of the return spring, but in this case, the cleaning blade 24 is prevented from retreating by the doweled gear 21, so that the carriage 2 Even after the reset pawl 33 passes, the cleaning blade 24 remains protruded.

While carriage 2 moves further to the right, recording head 1
Wiping is performed on the ink ejection port surface of 8 to ID.

In this case, the rotational force of the LF motor 18 has not been switched to the platen 6 drive side due to the movement of the carriage 2, and the pawl 30 of the holding lever 29 is connected to the pair of reset pawls 33 and 35 of the carriage 2 (FIG. 3). During the period in which the LF motor 18 is located between The state shown in FIG. 1 is returned.

In the ink suction operation (sequence) described later, LF
Due to the reverse rotation of the motor 18, the gear 21 with dowels rotates in the opposite direction by one rotation or more, but in this case, the dowel 23 of the gear 21 with dowels is inserted into the escape groove 49 (FIG. 2) of the rear end 25 of the cleaning blade 24. part, and gradually lift the cleaning blade 24 in the direction of arrow C (FIG. 2) against the spring 50 (FIG. 2) and return to its original position. Therefore, the cleaning blade 24 does not protrude toward the ink ejection port side.

While carriage 2 moves from left to right, record throat IA~
When cleaning of all the ink ejection orifice surfaces of the ID is completed, the reset pawl 35 (FIG. 3) of the carriage 2 engages with and passes the tip pawl 34 of the holding lever 29, and the cleaning blade 24 is reset to the initial state. Position (retracted position in Figure 1)
Then, the ink ejection port surface is cleaned (wiped)! 13
The work is finished.

The cleaning operation by the wiping means as described above can be performed multiple times by reciprocating the carriage 2.

This cleaning operation (wiping operation) can reliably remove dust, paper waste, or thickened ink adhering to the ink ejection port surface.

Next, recovery by ink suction from the ink ejection port
k 1.7 1. N 7 it5111-P x Cleaning of the ink ejection port mentioned above (cleaning or wiping)
When this is completed, the carriage 2 moves from right to left to a position where the recording heads IA to ID face the respective camps 22A to 22D, and stops at that position.

After the carriage 2 stops, the LF motor 18 is sequentially rotated.

As the gears continue to rotate in the same order, the rotational force of the doweled gear 21 is transmitted to its shaft 36 (Fig. 5), which rotates the pulley 37 (Fig. 5) that rotates together with this shaft, causing the timing belt ( The worm 39 rotates coaxially with the pulley 38 (FIG. 4).
Rotate.

In FIG. 4, the worm 39 is replaced by a worm wheel 40.
It meshes with the. A plurality of rectangular grooves 41 are formed on the shaft integral with the wormhole 40, and as the wormwheel 40 rotates, the rotating cam 26 coaxial with the wormwheel 40 fits into the rectangular grooves 41 and rotates at the same speed.

As the L F morph 18 continues to rotate, the embossment 42 of the cap housing 27 (Fig. 1) is engaged with the cam groove (not shown) of the rotary cam 26, and the cap housing 27 is connected to the recording heads IA to ID. The rubber caps 22A to 22D are brought into close contact with the respective ink ejection orifice surfaces, resulting in a camping state (camping closed).

A conduit 43,44 is connected to each rubber cap 22A-22D, conduit 43 is connected to vent hole 45, and conduit 44 is connected to pump 46.

When the capping state is reached, as shown in the timing chart of the ink suction operation in FIG. Even if the volume is compressed, the meniscus of the ink ejection orifice surfaces of the recording hoods IA to ID do not recede.

As the LF motor 18 continues to rotate in the forward direction, the protrusion 51 on the circumference of the cam disc rotates as the rotary cam 26 rotates, causing the vent valve support 5
2 in the direction of the arrow (Fig. 4) and open the ventilation valve 47.
The ventilation hole 45 is sealed (ventilation valve closed). This vent valve closing corresponds to point 82 in FIG.

When the worm wheel 4 (Fig. 4) continues to rotate with the camping closed and the ventilation valve closed, a plurality of wheel cams 53 (Fig. 4) are formed at positions with different diameter lengths in the radial direction of the worm wheel 40. , the plurality of wheel cams 53 engage with cams of the same diameter length on the casing 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 into the rotary cam (cam disc) 26 and the rectangular groove 41, the worm wheel 40 moves downward while rotating the rotary cam 26.

The movement of the worm wheel 40 pushes down the piston 55 of the pump 46 via the steel ball 54. Steel ball 54
is for not transmitting the rotation of the worm wheel 40 to the piston 55.

By pushing down the piston 55, the cylinder 5 of the pump 46
6 becomes a negative pressure, and ink is sucked from the ink discharge port through the conduit 44.

The downward movement speed of the worm wheel 40 can be controlled by the rotation speed of the LF motor 18, and by considering the movement speed of the worm wheel 40 and the amount of ink flowing in due to the negative pressure inside the cylinder 56, the ink discharge can be controlled. Ink suction from the outlet can be set at a predetermined negative pressure, and generation of dissolved air dissolved in the ink can be prevented.

When the worm wheel 40 moves to the lowest end (point 33 in FIG. 11) and continues to rotate in this lower end state, the upper protrusion 51 (FIG. 10) around the rotating cam (cam circle 1) 260 moves to the vent valve support 52. (Fig. 4, Fig. 1O), and the vent valve 47 (Fig. 4) connects the vent hole 45 to the atmosphere (
The ventilation valve is open, corresponding to point 34 in Figure 1F).

By controlling the rotational speed of the worm wheel 40 when it is in the lower end state, it is possible to control the time until the above-mentioned vent hole 45 communicates with the atmosphere.

When the inside of the cylinder 56 is in a negative pressure state and the vent hole 45 communicates with the atmosphere, the sucked ink inside the rubber cap 48 flows into the cylinder 56 through the conduit 44 together with the air flowing in from the conduit 43, and the ink remains inside the rubber cap 48. The quantity will be less.

The degree of negative pressure inside the cylinder 56 when the vent hole 45 is communicated with the atmosphere must be controlled by the rotational speed of the worm wheel 40 in order to keep the meniscus of the ink discharge port from retreating.

The reason for this is that before the vent hole 45 communicates with the atmosphere, ink is being sucked from the ink discharge port, and the air layer 59 of the sub-tank 58 behind the ink discharge port is under negative pressure.
This is because when the rubber camp is communicated with the atmosphere, the inside 48 of the rubber camp immediately becomes atmospheric pressure, causing the ink meniscus at the ink discharge port to retreat, and in order to prevent this, it is necessary to control the rotational speed of the worm wheel 40.

When the ventilation valve 47 is finished opening and the worm wheel 40 continues to rotate, the worm wheel 40 moves from the lowermost end to the uppermost end (initial status). This point corresponds to point 35 in FIG.

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

When the worm wheel 400 rotation position comes between 85 and S6 in FIG. 11, the worm wheel is switched from forward rotation to reverse rotation and rotated until the ventilation valve 47 is opened (point 84 in FIG. 11). By causing air to be sucked (empty suction) through the conduit 43, the ink remaining inside the rubber cap 48 during the above-described ink suction can be reliably discharged. If this empty suction is repeated several times, even more effects will be obtained.

゛ In the above explanation, when the worm wheel 40 rotates forward, it changes from the 83 state (moves to the lowest position) to the 3 state where the ventilation valve is open.
4 state, it is necessary to control the rotational speed of the worm wheel 40 so as to maintain a negative pressure that does not cause the meniscus of the ink ejection port to recede. This part of the control is carried out in the following manner. You can also do that.

That is, the rotation of the worm wheel 40 is stopped between the S3 state and the 84 state (see FIG. 11), and the sub tank 58
By ensuring that the air layer 59 reaches atmospheric pressure before proceeding to the firing sequence, the mechanism of the ink ejection port will not retreat.

After the above-mentioned empty suction is completed, the worm wheel 40 is
Continuing the forward rotation from the point between point 5 and point S6, the circumferential protrusion 51 of the rotating cam (cam disc) 2-6 similarly pushes the ventilation valve support 52 in the direction of the arrow, and the ventilation valve 47 is (point 37 in Figure 11).

At this time, since the flat part of the ventilation pulp 47 closes the ventilation hole 45, there is no volume change in this part, and the meniscus of the ink ejection port does not recede even in the camping closed state.

After passing through the closed ventilation valve 47 (point 37 in Figure 11), from the rear end of the closed camping (point 38 in Figure 11) to the open camping (point 89 in Figure 11), after closing the ventilation valve 47. ＠ (point 310 in Figure 11) to open the ventilation valve 47 (point Sll in Figure 11), and then reach the end (same as the initial pleasure), that is, point 312 in Figure 11 (same as the SO point). Complete a series of actions.

Printing defects can be prevented by executing the recovery operation described above, but as a more reliable recovery operation, the following sequence may be added between the above-mentioned point S7 and point Si2.

The operation from point S7 to point Si2 to be added will be described below.

As mentioned above, one of the causes of printing defects is air entrapment from the ink ejection ports or air stagnation in the vicinity of the ink ejection ports and in the ink path leading to the ink ejection ports.

As mentioned above, the removal of these air can be almost completely recovered by the ink suction operation from the ink ejection ports, but in very rare cases, the ink supply pipes 62 (No. (Figure 4) Or, if air adheres to the filter 63 in the ink supply pipe 62 in a valve state and the air cannot be completely removed by the ink suction sequence described above, splashes or satellites are generated by ink droplets during recording. There is.

In order to remove and recover this, first, the worm wheel 40 is reversely rotated from the initial position SO point (or Si2 point) of the recovery operation sequence to between the aeration pulp 47 (point S7) and the rear end of the capping close (point S8). From that position, the rotation is switched to forward rotation and returns to the initial position SO (point 312).

By repeating this operation multiple times, the rubber cap 2
When the ink discharge ports 2A to 22D are placed in a capping state, the pressure inside the rubber cap 48, which is in a sealed state, increases, and air is forcibly sent from the ink discharge ports.

By feeding the air in this manner, the attached air in a bubble state is removed.

After completing the above operations, if the ink suction sequence from the SO point to the S12 point described above is performed, the ink ejection failure can be more completely eliminated.

〔effect〕

According to the inkjet recording apparatus according to the present invention described above, the cleaning means (blade) is put into a functional state by using a part of the operation sequence of suctioning ink from the ink discharge port, and the movement of the carriage causes the cleaning device (blade) to become functional. In addition, the movement of the carriage at different times can be used to apply the cleaning means, so there is no need for a special driving source to clean the ink ejection orifice surface. A recovery device with a simple structure and high reliability can be obtained, and an ink-side recording device that can be miniaturized and reduced in cost can be replaced.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the main structure of an inkjet recording apparatus according to an embodiment of the present invention, and FIG. 2 is a line n in FIG. 1.
-N is a rear view, FIG. 3 is a front view of the carriage as seen from line ■-■ in FIG. 1, FIG. A plan view of the recovery device in FIG.
Fig. 6 is a front view taken from line VI-Vl in Fig. 5, Fig. 7 is a left side view taken from line ■-■ in Fig. 5, and Fig. 8 is a central longitudinal section of the recovery device shown in Fig. 5. 9 and 10 are cross-sectional views at different levels of FIG. 5 and FIG. 11, respectively.
The figure is a timing chart illustrating an operation sequence of a recovery device for an inkjet recording apparatus according to the present invention. IA~ID-・・・・・・・・・・To record・2 do, 2-・・・・・・・・
−1−−−−・Carriage, 18・−・−・・・・−・
Motor, 22A-22D-...Cap,
24・−・・・・・−Cleaning blade, 33
゜35−・−・−・−・・・・Reset claw, 46...
・・・・・・Suction pump, 47・・・・・・−・−
Ventilation valve, 48...--- Inside the camp, RP...-----Recovery device.

Claims (4)

[Claims] (1) In an inkjet recording apparatus equipped with a recovery device for preventing ink discharge failure of a recording head, the recovery device includes a cap that covers an ink discharge port, a ventilation valve that opens and closes the inside of the cap to the atmosphere, and a negative The cleaning device includes an ink suction means having a suction pump that generates pressure, and a wiping means having a cleaning blade that moves forward and backward with respect to the ink discharge port, and when a motor for performing a sequence operation of the ink suction means rotates in one direction, the cleaning An inkjet recording device configured to project a blade and stop the cleaning blade in a retracted position when the motor rotates in the opposite direction. (2) The ink jet recording apparatus according to claim 1, wherein a power transmission unit for protruding the cleaning blade is set closer to the motor than a drive mechanism of the ink suction means. (3) The inkjet recording apparatus according to claim 1 or 2, wherein the carriage is provided with a reset claw for returning the cleaning blade to its initial position. (4) The inkjet recording apparatus according to claim 3, wherein the reset claws are provided at two locations at a predetermined interval.