JPS59224354A - Ink jet printer - Google Patents

Abstract

PURPOSE:To prevent an injection inoperative condition of ink, by interlinking with a pump operating lever up to recovery of inside pressure of a sub-tank, locking a capping-relief mechanism and later, by transmitting an electric current to piezoelectric elements and indicating the relieved condition by their vibrating noise. CONSTITUTION:For switching to an injection operative condition of ink is performed by pushing a swiching lever 17, capping a nozzle with a cap 13, locking with a lock-lever 26 and further, by continued pressing for starting a pump 9, causing recovery to operative condition of ink and air suction. At this moment, a switch 23 is placed in ''ON'' position. Then, at the end of recovery of the injection operation of ink, when said lever 17 is released, the locking condition by the lever 26 is attained again and by bringing the position of the switch 23 to ''OFF'' position, after the specified lapse of time, constant time piezoelectric elements are driven and at the same time, a solenoid 31 is excited. By excitation of the solenoid, even if the lever 26 is rotated in the clockwise direction, the lever 17 is kept in its condition by a spring 28 and relief of the capping is judged by vibrating worse of the piezo-elements, allowing lifting of the lever 17 hand. Thus, the injection inoperative condition of ink caused by inadvertent releasing of capping can be prevented.

Description

TECHNICAL FIELD The present invention relates to an inkjet printer, and more particularly to an inkjet printer with an improved ink suction recovery mechanism.

Prior Art An example of a conventional ink suction recovery mechanism of this type of inkjet printer is shown in FIG.

In FIG. 1, numerals 1 and 2 indicate main tanks, each of which houses an ink bag 3.

Each ink bag 3 of the main tanks 1 and 2 is connected to a sub tank 5 mounted on the carriage side via a supply tube 4.
connected to the side.

A thin supply pipe 6 is housed on the sub-tank 5 side, and one end of the supply pipe 6 is connected to the nozzle 7 side. Supply pipe 6
The other end is immersed in ink 8 in sub-tank 5.

On the other hand, the reference numeral 9 indicates a pump, and the pump 9 is provided with a piston 10, and an operating lever 11 is connected to the piston 10.

A suction tube 12 is connected between this pump 9 and the sub-tank 5.
Further, the pump 9 and the ink suction cap 13 are connected via a nozzle tube 14.

Although not shown, the nozzle 7 is equipped with a cylindrical piezo element (piezoelectric element), and a voltage is applied to the piezo element according to a printing command to contract the glass tube that constitutes the nozzle. The ink is ejected to perform printing.

Further, a reference numeral 15 indicates a return pipe that serves to return the drain ink from the pump 9 to the return ink chamber 16 on the main tank 1 side.

By the way, to explain the positional relationship between the suction tube 12 and the nozzle tube 14, the suction tube 12 is located at a higher position, and the nozzle tube 14 is located at a lower position.

Therefore, when the operating lever 11 is pressed to create a negative pressure above the piston 10 of the pump 9, the negative pressure is first supplied to the suction tube 12 side, and at this time, the nozzle tube 1
The 4th side is closed.

Therefore, in the first step, the pressure inside the sub-tank 5 is reduced, and ink is introduced into the sub-tank 5 from the main tanks 1 and 2.

Further, by pushing down the piston 10, ink from the nozzle 7 is sucked through the cap 13.

When ink enters the sub-tank and enters the suction tube 12 by operating the pump 9, the suction tube 12
The resistance on the side increases, and after that, ink is mainly sucked from the nozzle side.

As a result, it is possible to remove air bubbles and the like within the nozzle and restore ink ejection.

On the other hand, when ink is sucked from the suction tube 12 and nozzle tube 14 by suction from the pump, the pressure inside the sub-tank 5 is reduced. Therefore, if the cap 13 is removed before the internal pressure of the Saralink 5 returns to the original pressure after suction, the internal pressure of the sub-tank 5 will not return and the nozzle 7
This causes air to be sucked into the nozzle, resulting in non-ejection.

Therefore, it is necessary to wait for the cap to be released until the internal pressure returns to its original level due to the supply of ink from the main tank.

Therefore, in the past, this time was electrically counted after the pump was operated, and the cap release was instructed by flashing a lamp or the like.

However, since the user of the device can freely operate the pump and release the cap, the cap can be removed even if the user does not understand the meaning of the blinking lamp or is careless. However, there is a drawback in that releasing the cap even after carrying out an ejection recovery operation results in an ink non-ejection state.

Purpose The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional technology, and it is possible to release the cap without using many extra parts and to prevent ink from being ejected. The purpose of the present invention is to provide an inkjet printer configured to enable the following.

Embodiment FIG. 2 and subsequent drawings explain one embodiment of the present invention. In each drawing, the same or corresponding parts as those in FIG.

Fig. 2 shows the entire structure of the ink failure port and return mechanism. In the figure, the reference numeral 17 is a rotary lever, one end of which is rotatably fixed to the device via a shaft 18. It is supported on the shaft.

A projecting piece 19 is provided on one end side of the rotating lever 17, and a guide hole 19a shaped like a "<" is formed in this part.
has been done.

A pin 21 of the cap 13, which protrudes through a guide hole 20a formed on the side surface of the cap holder 20, is slidably fitted into the guide hole 9a.

A protrusion 17a is provided on the back surface of the rotary lever 17 at a position corresponding to the operating lever 11 of the pump 9. Furthermore, a bottle 17b is provided protruding from the side surface of the rotating lever 17, and this bottle 17b is attached to a hook 2 provided on the device side.
2 is locked.

The reference numeral 23 indicates a switch that detects the operation of the rotary lever 17. This switch 23 is turned on and off by a protrusion 17C protruding from the rotary lever 17.

By the way, as shown in an enlarged view in FIG. 4, the cap 13 has a cap rubber 13a at its tip, and a spring 24 loaded in the cap holder 20 applies a force in the direction of protruding from the cap holder 20. It is being

On the other hand, as shown in FIG. 5, a hook 25 is protruded from the lower end of the rotary lever 17, and a role lever 26 is disposed opposite the hook 25.

The lock lever 26 is configured to be rotatable around a horizontal shaft 27 fixed to the device side and tilted in the axial direction of the shaft 27, and the side facing the seven hooks 27 has a hook shape. Two slopes 26a and 26b are formed.
is formed.

Furthermore, the lock lever 26 is given the ability to rotate in the counterclockwise direction in FIGS.
．． 29-2 The limit of rotation is restricted.

Further, the lower end of the lock lever 26 is rotatably supported on a rod 31a of a solenoid 31 via a shaft 3o.
As shown in FIG. 7, a clearance is provided so that the shaft 3o can move freely in the axial direction.

Next, the operation of this embodiment configured as above will be explained.

Before starting the ink non-discharge recovery operation, the rotary lever 17 is rotated clockwise in the figure as shown in the third example, and the pin 17b is engaged with the hook 22, and the protrusion 17a is locked away from the operating lever 11 of the pump 9.

The rotating lever 11 is given the habit of rotating clockwise in the figure about the shaft 18 by a force such as a spring (not shown).

In this state, the pin 21 integrated with the cap 13 is
It is located at the upper end of the ``<''-shaped guide hole 19a,
The cap 13 is drawn into the cap holder 2o.

The hook 25 is located away from the lock lever 26 as shown in the 5th edition, and the lock lever 26 is tilted to the left in FIG. 5 (3) 9 due to the pressing force of the screw coil spring 28.

If you want to recover from the ink ejection failure from this state, first release the engagement between the hook 22 and the pin 17b, and push the rotation lever 17 counterclockwise in the figure as shown in FIG. 3(B). Rotate in the direction.

This action causes the pin 21 integrated with the cap 13 to
It moves along the ``''-shaped guide hole 19a and reaches the bent part.

As a result, the pin 21 is given the freedom to move in the elongated hole 20a toward the right in FIG. The tip is completely capped.

According to this rotational movement of the rotational lever 17, as shown in FIG.
As shown in the figure, hook 2°5 descends and lock lever 26
At the same time, the lock lever 26 is pushed from the inclined state to the upright state against the pressing force of the torsion coil spring 28.

Then, it eventually climbs over the slope 26 and is hooked by the hook-shaped hook portion, and the rotating lever 17 is locked so that it cannot return to its original state.

On the other hand, from this state, the rotating lever 17 is further moved as shown in FIG.
When it is rotated counterclockwise as shown in , the protrusion 17a presses the operating lever 11 of the pump 9, so the pump 9 is activated, and the ink non-discharge recovery operation and air suction from the sub-ink tank are performed. .

At this time, as shown in FIG. 3(C), the protrusion 17C protruding from the lower end of the rotary lever 17 presses the switch 23, so that the switch 23 is turned on.

Since this recovery operation is accompanied by counterclockwise rotation of the rotation lever 17, the hook 25 further descends and engages with the lower inclined surface 26b of the lock lever 26, as shown in FIG. 5(C). Then, the lock lever 26 is rotated to the right against the pressing force of the torsion coil spring 28 in FIG. 5(C).

When the recovery operation is completed and you release your hand from the rotating lever 17, the operating lever 11 is pushed upward by a spring (not shown) housed in the pump 9, so the rotating lever 17 returns to its original state. However, the hook 25 is locked to the lower side of the inclined surface 26a at the upper end of the hook-shaped lock lever 26, and the locking state is lost. Therefore, the cap 13 will not come off from the nozzle 7.

By the way, during the operation returning from FIG. 3(C) to FIG. 3(B), the switch 23 is disengaged from the protrusion 17C and is turned off. After this off state is maintained for a certain period of time until confirmation of completion of pumping by a timer of a control circuit as will be described later, the solenoid 31 is energized. When the rod 31a is operated in the retracting direction as shown by the arrow in FIG. 6, the lock lever 26 is rotated clockwise about the shaft 27 in FIG.

As a result, as shown in Figure 5 (DJ), the lock lever 26
Since the hook 25 is shifted to the side, the locking state of the hook 25 by the lock lever 26 is released.

The rotating lever 17 is maintained in this state by the torsional force of the screw coil spring 28 even after the energization of the solenoid 31 is terminated.
When the lock lever 26 is pulled up, the lock lever 26 returns to its original state as shown in FIG. 5 (3) by the force of the screw coil spring 28, and the rotating lever 17 also returns to the initial state shown in FIG. 3 (3). return.

In this way, the cap can be completely locked to prevent it from being released while the pumping operation is being performed, thereby preventing it from being accidentally released by the user. A paradoxical accident in which the cap is not released during printing and an ink non-discharge state occurs during the ink non-discharge recovery operation does not occur.

By the way, electrical control of the timer and piezo element by the operation of the above-mentioned rotary lever is performed by a control circuit as shown in FIG.

When the rotation lever 17 is pressed and the switch 23 is turned on,
Thereafter, when the rotary lever returns to the capping position and the switch 23 is turned off, the CPU (Central Processing Unit) detects this via the signal line t1.

The CPU then operates the timer TM via the signal line t2.

The timer TM is set with an experimentally determined time period for the pressure in the sub-tank 5 to return to its original atmospheric pressure.

When the timer TM is activated and a certain period of time has elapsed, the signal m4
K pulse is output, monostable multivibrator 1 operates, outputs a signal for a certain period of time, and inverter I
Turn on the transistor TR through N solenoid 3
1 to release the locked state by the lock lever 26 as described above.

On the other hand, another monostable multivibrator M
M2 is activated by the fall of the output signal of MM1, outputs a high level signal for a certain period of time, for example, about 0.5 seconds, and opens AND gate A.

A pulse signal from the oscillator O8C is input to AND gate A, and when a high level signal from MMl is input to AND gate A, AND gate A outputs a constant frequency pulse from OSC for a certain period of time. The signal is input to the OR gate' group OR.

The print signal PS during normal printing is input to the other input terminal of the OR gate group OR, but the level of this signal is at a low level during the recovery operation.

Therefore, the pulse signal from the oscillator O8C is transmitted to the driver D.
The piezo element PZ is driven via R to perform an ink ejection operation.

Note that during normal printing, contrary to the above operation, MMI,
MM2 does not operate, the controller A closes, and only the print signal PS is input to the driver DR via the OR gate to drive the piezo element to eject ink and perform printing.

By the way, when the piezo element is driven by a pulse from the oscillator O8C during the above-mentioned ink non-discharge recovery operation, the piezo element generates a vibration sound for the duration of the pulse's energization.

This vibration sound is so loud that it can be clearly heard by the user, and if this vibration sound is heard, it means that a recovery operation for ink failure has been performed, and that the capping state by the lock lever 26 has been released.

Therefore, the user can return the rotary lever 17 to its original position only after hearing this vibration sound.

Since this embodiment is configured as described above, the cap can be kept locked until the air pressure inside the sub-tank returns to normal, and the release of the capping lock can be detected by the vibration sound of the piezo element after a certain period of time. It is possible to reliably fill the inkjet nozzle with ink and restore the pressure in the sub-tank.

In fact, it is possible to accurately know when to release the cap by the vibration sound of the piezo element without the need for any special display means such as an indicator lamp.

Since the small piezo element is energized, ink is always ejected, and the reliability of the ink ejection failure recovery operation can be improved.

Effects As is clear from the above explanation, according to the present invention, the capping release mechanism linked to the lever that operates the pump is locked until the pressure in the sub-tank is restored, and after this period has elapsed, the piezo element is energized. Since a structure is adopted in which the vibration sound is used to notify the release of capping, it is possible to prevent ink from being ejected due to inadvertent release of capping during the recovery operation.

[Brief explanation of the drawing]

FIG. 1 is a perspective view explaining a conventional structure, FIG. 2 and the following are illustrations of an embodiment of the present invention, and FIG.
3(3) to (C) are explanatory diagrams showing the structure and operation of the rotating lever, FIG. 4 is an explanatory diagram showing the structure of the cap part,
Figures 5(3) to 3) are explanatory diagrams showing the structure and operation of the locking mechanism, Figure 6 is a front view of the lock lever, Figure 7 is a bottom view showing the installation state of the lock lever, and Figure 8 is an explanatory diagram showing the structure and operation of the lock mechanism. FIG. 2 is a block diagram of a control circuit. 1.2... Main tank 4... Supply tube 5
...Sub tank 7...Nozzle 8...Ink 9...Pump 12...Suction tube
13... Cap 14... Nozzle tube 17
...Rotating lever 20...Nozzle holder 23.
...Switch 25...Hook 26...Lock lever 28...Screw coil spring 31...
Nlenoid. Patent applicant Canon Corporation 273 Figure 1 Figure 2 Figure 3 (A) Figure 3 (B) 27
4- Figure 5 (A) Figure 5 CB) Figure 5 (C) Figure 5 (D) Figure 7
Figure 6

Claims (1)

[Claims] Ink suction recovery is an ink jet printer equipped with an ink suction recovery mechanism that attaches a cap to an inkjet nozzle and sucks ink from the inkjet nozzle, filling the inkjet nozzle with ink and allowing normal ink ejection. The cap is locked to prevent it from being released until the pressure in the sub-tank in which the inkjet nozzle is installed returns to normal.
Furthermore, the inkjet printer is characterized in that the piezo element used for ink ejection is energized when the air pressure in the sub-tank returns to normal, and the vibration sound of the piezo element notifies the time to release the cap.