JPS62238753A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To provide a recovery device of a best suitable ink jet recorder for realization of an automatic recovery action to perform a series of recovery procedures by arranging a worm wheel on the same shaft as a rotary cam and fitted with the rotary cam in such a way that it may slide in a shaft direction. CONSTITUTION:A worm 39 is engaged with a worm wheel 40, and a plurality of rectangular grooves 4 are formed on a shaft formed integrally with the worm wheel 40. As the worm wheel 40 rotates, a rotary cam 26 provided on the same shaft as the worm wheel 40 is fitted to the rectangular groove 41, rotating at the same speed. When a line feed motor 18 rotates continuously, a cap casing 27 is shifted to the direction of a recording head 1A-1D, because an embossed part 42 of the cap casing 27 is intermeshed with a cam groove of the rotary cam 26. This enables a rubber cap 22A-22D to stick to the surface of an ink discharge outlet to realize a capping state. Conduit tubes 43, 44 are connected to each rubber cap 22A-22D, and the conduit tube is connected to a ventilation hole 45. The conduit tube 44 is linked to a pump 46.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an inkjet ink outlet port of an inkjet recording apparatus. This invention relates to a recovery device that prevents ink discharge failure due to stale ink or ink discharge.

[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 ink droplet is driven based on a data signal to form flying ink droplets from an ink ejection port 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 orifices are capped or A recovery device is provided that sucks ink from the outlet. Conventionally, this type of recovery device has been configured to be activated by a manual operation such as a lever operation by a user to recover from a malfunction of the recording head when a malfunction occurs in the recording head such as an ink discharge failure.

However, such a conventional recovery device requires an operation method instruction label or the like to allow the user to perform the recovery operation, which poses a problem of making the user feel complicated.

Further, if the operation is not performed in accordance with the instructions, there is a problem in that recording ink is wasted and produced by suction.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to provide a recovery device for an inkjet recording apparatus that can solve the problems of the prior art described above and is suitable for realizing an automatic recovery operation in which a user simply inputs a signal using a switch key to perform a series of recovery operations. It is to be.

〔overview〕

The present invention provides a recovery device including a cap that covers an ink ejection orifice surface, a rotary cam that opens and closes a ventilation valve that communicates the inside of the cap with the atmosphere, and moves the camp forward and backward with respect to the ink ejection orifice surface; a suction pump that generates a negative pressure, and a worm wheel having a radial cam portion for driving the suction pump, the worm wheel being disposed coaxially with the rotating cam and axially oriented with respect to the rotating cam. Due to the sliding configuration,
This aims to achieve the above objectives.

〔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 (four in the illustrated example) of recording heads IA, IB, IC, and ID 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, 0.8 (about the size of a fin).

During the scanning movement of the carriage 2, a recording signal is output to the recording heads IA to ID via the flexible wiring 7, and the recording signals are output to the recording heads 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 printing, dirt or paper scraps may adhere to the vicinity of the ink ejection ports (for example, dot forming means consisting of 24 orifices) of the print heads 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.

Accordingly, the idle pulley 8, which supports the rotation of the timing belt 5 at one end, rotates. As the idle pulley 8 rotates, a planetary gear group 9 for deceleration is provided coaxially with the idle pulley 8.
It also rotates.

When the carriage 2 moves to a predetermined position in the direction of the recovery gear ZRP, 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 the arrow 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 being engaged with the ratchet gear 16 to being 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) provided at the left end portion.

When the recovery key is operated as described above, the carriage 2 is opened to record the rubber caps 22 corresponding to the hoods 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 surface (the surface on which ink ejection ports are formed) of the recording head IA-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 3 engages with the rear end 25 of the cleaning blade 24, and the cleaning blade is driven by a return spring ( (not shown)
It is projected in the direction of the carriage 2 against the.

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 line 1--m in FIG. 1, and FIG. 4 shows a schematic overall configuration of the recovery device RP.

Incidentally, as the LP motor 18 rotates, the rotating cam 26 (FIG. 4) of the recovery device RP, which rotates during 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, movement of the cap housing 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 the carriage 2 moves further to the right, the recording head I
Wiping is performed on the ink ejection orifice surfaces of A 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 is returned to the state shown in FIG.

LF in the ink suction operation (sea fence) described later.
Due to the reverse rotation of the motor 18, the gear 21 with dowels rotates in the opposite direction by one or more rotations. The cleaning blade 24 passes through the section R49 (FIG. 2), and gradually lifts the cleaning blade 24 in the direction of arrow C (FIG. 2) against the spring 50 (FIG. 2) and returns to its original position. Therefore, the cleaning blade 24 does not protrude toward the ink ejection port side.

While the carriage 2 moves from left to right, the recording head 18~
When cleaning of all the ink ejection orifice surfaces of 1D is completed, the glue setting pawl 35 (FIG. 3) of the carriage 2 engages 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)
, and the cleaning (wiping) operation of the ink ejection orifice surface is completed.

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, a recovery operation by ink suction from the ink ejection port will be explained.

When the cleaning (cleaning or wiping) of the ink ejection ports described above is completed, the carriage 2 moves the recording heads IA to ID.
moves from right to left to a position facing each of the caps 22A to 22D, and stops at that position.

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

As this forward rotation continues, the rotational force of the doweled gear 21 is transmitted to its shaft 36 (Fig. 5), rotates the pulley 37 (Fig. 5) that rotates together with this shaft, and rotates the timing belt (Fig. 5). (not shown) to rotate the pulley 38, and the worm 39 (FIG. 4), which is rotating coaxially with the pulley 38, is rotated.

In FIG. 4, the worm 39 is replaced by a worm wheel 40.
They mesh with each other. 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 moves into the rectangular grooves 4.
1 and rotate at the same speed.

As the LF motor 18 continues to rotate, the embossment 42 of the camp housing 27 (FIG. 1) is engaged with the cam groove (not shown) of the rotating cam 26, and the camp housing 27 is connected to the recording heads IA to ID. The rubber camps 22A to 22D are moved in the direction, and the rubber camps 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 camp 22</b>A to 22</b>D, conduit 43 is connected to a vent 45 , and conduit 44 is connected to a pump 46 .

When the camping state is entered, as shown in the timing chart of the ink suction operation in FIG. Even if the volume of the recording head 18 to ID is compressed, the meniscus of the ink ejection orifice surface of the recording heads 18 to ID does 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 capping 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 negative and positive, and ink is sucked from the ink discharge port via 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 circumferential upper protrusion 51 (FIG. 10) of the rotating cam (cam disc) 26 touches the ventilation valve support. 52 (FIGS. 4 and 10), and the vent valve 47 (FIG. 4) connects the vent hole 45 to the atmosphere (the vent valve is open, corresponding to point 34 in FIG. 11).

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 subtank 5 behind the ink discharge port has a negative pressure.
This is because when the rubber cap is communicated with the atmosphere, the inside of the rubber cap 48 reaches 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 returns the piston along the formation of the wheel cam 53. A
Press + to return from the bottom to the top (initial pleasure). This point corresponds to point 85 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 rotational position of the worm wheel 40 reaches between 35 and S6 in FIG. 11, the forward rotation of the worm wheel is switched to the reverse rotation until the ventilation valve 47 is opened (point 84 in FIG. 11). By rotating and suctioning air through the conduit 43 (empty suction), the ink remaining in the inside 48 of the rubber cab 2 at the time of ink suction described above can be reliably discharged. If this empty suction is repeated several times, even more effects will be obtained.

In the above description, when the worm wheel 40 rotates forward from the 83 state (moves to the lowest end) to the 84 state where the ventilation valve is open, the worm wheel 40 is rotated so that the pressure is at a level of negative pressure that does not cause the meniscus of the ink ejection port to retreat. As mentioned above, it is necessary to control the speed, but this part of control can also be implemented by the following method.

That is, the rotation of the worm wheel 40 is stopped between the S3 state and the 34 state (see FIG. 11), and the sub tank 5 is
If the air layer 59 of No. 8 is made sure to reach the atmospheric pressure before proceeding to the sea fence, 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) 26 similarly pushes the vent valve support 52 in the direction of the arrow and closes the vent valve 47. (37 points in Figure 11).

At this time, since the flat part of the ventilation valve 47 closes the ventilation hole 45, there is no volume change in this part, and the meniscus of the ink discharge port does not retreat 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 capping open (point 89 in Figure 11), after closing the ventilation valve 47. from the end (SIO point in FIG. 11) to the opening of the ventilation valve 47 (Sll point in FIG. 11), and then the terminal point (same as the initial state), i.e. the 512 point in FIG. 11 (same as the SO point). ), completing the series of operations.

Printing defects can be prevented by executing the 15 recovery operations described above, but for a more reliable recovery operation, the following sea fence may be added between the 37 points and 512 points mentioned above. .

The operation from point S7 to point 512 to be added will be explained 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) Alternatively, air adheres to the filter 63 in the ink supply pipe 62 in a valve state, and the air cannot be completely removed by using the ink suction seam fence described above, causing splashes or satellites of ink droplets during recording. There are cases.

In order to remove and recover from this, first, the worm wheel 40 is reversely rotated from the initial value of the sea fence 2SO point (or Si2 point) to between the ventilation valve 47 (point 37) and the rear end of the capping opening (point 3B). Then, from that position, the rotation is switched to forward rotation and returns to the initial position SO point (Si2 point).

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 the above operations are completed, ink suction fencing from the SO point to the S12 point described above can be performed to more completely eliminate ink ejection failures.

According to the present invention described above, the worm wheel for driving the suction pump is provided which is coaxially decelerated with the rotary cam that controls capping, so the structure of the recovery device can be made smaller and simpler, and the number of parts can be reduced. Provided is an inkjet recording apparatus that can reduce the amount of damage and improve the reliability and certainty of the recovery operation.

[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 vt-vr 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 operational sequence of a recovery device for an ink chef (ink chef) printing apparatus according to the present invention. ■A~ID...----Record head, 2---
・-・・・Carriage, 18・・・・・・・・・Motor, 22A~22D−・・・・・・・・Cap, 26
・-----1--・One rotation cam, 40...
−・・・Worm wheel, 46−−−−−−
Suction pump, 47・・・・・・・・・vent valve,
48...-m---- Cap inside, PR...
...~Recovery device.

Claims (1)

[Claims] (1) In an inkjet recording apparatus equipped with a recovery device for preventing ink discharge failure of the recording head, the recovery device opens and closes a cap that covers the ink discharge port surface and a ventilation valve that communicates the inside of the cap with the atmosphere. a rotating cam that moves the cap forward and backward relative to the ink discharge port surface;
The cap includes a suction pump that generates a negative pressure in the cap, and a worm wheel having a radial cam portion that drives the suction pump, and the worm wheel is arranged coaxially with the rotating cam and is connected to the rotating cam. An inkjet recording device characterized in that the inkjet recording device is mounted so as to be slidable in an axial direction.