JPH0632924B2 - Recovery mechanism - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a recovery mechanism for recovering or maintaining an ink ejection state of a recording head, and in particular, an ink recovery member that recovers ejected ink and increases its volume. The present invention relates to a recovery mechanism that detects a full state of an ink storage member and regulates an ink discharge operation.

[Prior Art] An inkjet printer is an example of a recording apparatus having a discharge recovery mechanism for recovering or maintaining the ink ejection state of a recording head. In an inkjet printer, ink droplets are ejected from nozzles provided in a recording head and adhered to recording paper to perform recording. For this reason, the ink may not be ejected properly or may not be ejected due to thickening of ink at the tip of the nozzle due to use environment such as temperature and humidity, clogging of the nozzle due to dust such as paper dust on the recording paper, and intrusion of air bubbles into the nozzle. If this occurs, recording will not be performed properly.

Therefore, in many cases, the inkjet printer is provided with an ejection recovery mechanism for recovering the defective or non-ejected state of the ink. Such an ejection recovery mechanism normally recovers the normal ejection state by sucking or pushing out the ink in the nozzle with high pressure and discharging the ink, dust, bubbles, etc., which have increased in viscosity, out of the nozzle together with the ink. is doing.

As a specific configuration, for example, a suction cap connected to a suction pump that exerts a negative pressure on the nozzle is pressed against the tip of the nozzle with the ejection failure, and the negative pressure generated as a result of driving the pump sucks the ink. Then, a configuration in which the ink in the nozzle is discharged is known.

In this case, the ejected ink is guided to a member (hereinafter referred to as a waste ink reservoir), which is provided at a desired position in the apparatus, and collects and stores the ink, and is stored therein. This waste ink reservoir is replaced as needed when a new ink for recording is replaced.

However, at the timing when the waste ink is processed at a certain point such as when the recording liquid (ink) is replenished or the ink cassette is replaced, the ejection failure and non-ejection of the ink droplets from the nozzles frequently occur, and the recovery operation is performed many times. When a larger amount of ink is discharged than the capacity of the waste ink reservoir, the ink may overflow from the waste ink reservoir. In this case, not only the discharged ink leaks into the device and is contaminated by the ink, but if the ink is conductive, the electric circuit in the device may be immersed in the ink, which may cause a short circuit and damage the electric circuit. is there.

In particular, recently, in order to reduce the size of the entire apparatus, the capacity of the waste ink reservoir is often set to be small, so that there is a problem that the above-mentioned inconvenience may occur.

The above is not limited to the case of the ink jet printer, and includes an ejecting unit that ejects ink from the recording head regardless of the recording operation, and a storage member that collects and stores the ejected ink. This applies to a recording device that has a recovery mechanism that recovers or maintains the state.

[Objective] The present invention has been made in view of the above problems.
In a recovery mechanism for recovering or maintaining an ink ejection state of the recording head, the recovery mechanism comprising: a discharging unit that discharges ink from the recording head regardless of a recording operation; and a storage member that collects and stores the discharged ink. Detects the full state of the storage member before the ink overflows from the member,
A recovery mechanism capable of reliably preventing the inside of the recording apparatus from being contaminated with the ink and the electric circuit from being damaged by the leaked ink by stopping the operation of the discharging means in order to stop the discharge of the ink from the recording head. Is intended to provide.

[Examples] The present invention will be described in detail below based on the examples shown in the drawings. Here, an ink jet printer to which the device of the present invention is applied is taken as an example.

[First Embodiment] FIG. 1 shows the configuration of an ink supply system and an ejection recovery mechanism of an inkjet printer according to a first embodiment of the present invention. In the figure, reference numeral 1 indicates a main tank that stores recording ink, and the ink in the tank is supplied via a tube 2 into a sub tank 3 provided in the inkjet head. The sub-tank 3 is provided with a nozzle 5 that sucks the ink 4 in the sub-tank 3 and discharges it as an ink droplet to perform recording.

Further, a reference numeral 6 in the figure is a suction cap which is connected to a pump 8 via a tube 7, and is fitted to the tip of a nozzle 5 as shown in the figure when the discharge is recovered. When the discharge is restored, the ink in the nozzle 5 is sucked by the pump 8 through the cap 6 and the tube 7 by the negative pressure generated by driving the pump 8. The sucked ink is guided from the pump 8 through the tube 9 to the waste ink reservoir 10 and stored therein.

The structure of the waste ink reservoir 10 is as shown in FIG. As shown in the figure, the waste ink reservoir 10 is formed in the shape of a tank having a substantially rectangular parallelepiped shape, and an ink absorber 11 having a substantially rectangular parallelepiped shape is accommodated therein. The ink absorber 11 has a characteristic that it prevents the stored ink in the waste ink reservoir 10 from rocking to prevent ink leakage, and absorbs ink to increase its volume (swell) as will be described later. In order to prevent the waste ink from overflowing by utilizing the characteristics, the height and width dimensions are formed smaller by a predetermined amount than the height and width dimensions inside the waste ink reservoir 10. As such materials,
For example, a puff material used for makeup, a porous sponge body (cellulose acetate foam, vinyl acetate foam) used for wiping the moisture of a photographic film, a felt material, a high-absorbency resin (for example, trade name Sun Wet, manufactured by Sanyo Kasei Co., Ltd.) and the like. Also, waste ink reservoir 10
The tip portion of the tube 9 described above is inserted into one side surface of the tube.

Further, the ceiling and bottom surfaces inside the waste ink reservoir 10 are electrodes for detecting whether or not the swelling state due to the ink absorber 11 in the waste ink reservoir 10 absorbing the ink has reached a predetermined amount. The contacts 12a and 12b are fixed. The contacts 12a and 12b are respectively connected to signal destinations l1 and l2 guided to the side surface of the waste ink reservoir.

Further, in the above configuration, when the pump 8 is an automatic pump, the pump 8 and its driving yarn are configured as shown in FIG. 3, for example. As shown in the figure, a piston 13 is vertically slidable in a cylindrical pump 8, and a substantially L-shaped pump lever 14 is integrally formed on a shaft 13a of the piston 13. There is. A rack 14a is formed outside the bent tip of the pump lever 14, and a gear 16 connected to a drive shaft of a motor 15 as a drive source is meshed with the rack 14a.

In this configuration, when the motor 15 is driven in the normal direction and the reverse direction, the gear 16 is rotated in the normal direction and the reverse direction, and the pump lever 14 meshed with the gear 16 is moved up and down to move the piston 13 up and down to generate a negative pressure. Ink is sucked from the nozzle 5 through the tube 7 and the cap 6.

The motor 15 having the above configuration and the signal destinations 11 and 12 of the waste ink reservoir 10 described above are connected to the control circuit shown in FIG. By this control circuit, the swelling state of the ink absorber 11 in the waste ink reservoir 10 is detected, and the drive control of the motor 15 is performed based on the detection result.

In the control circuit shown in the figure, the waste ink reservoir 10 described above is used.
The signal destination l1 connected to the contact 12a of the CPU is a CPU (central processing unit) 1 that controls the entire ink jet printer.
7 and the power source Vcc via the resistor R1.
It is connected to the. The other end of the signal line 12 connected to the contact 12b is grounded.

Here, the CPU 17 monitors the signal level of the signal line 11,
It is configured to output a signal of the same level as that level to the signal line l3.

The signal line 13 is connected to one input of each of the two AND gates 18a and 18b. The other inputs of the AND gates 18a and 18b are connected to signal lines l4 and l5 for guiding the motor drive signal of the CPU 17, and the outputs are connected to a motor driver 19 that drives the motor 15.

Next, the operation of the present embodiment having the above-described structure when discharging ink will be described.

Discharged by the recovery operation of the discharge recovery mechanism shown in FIG.
When the amount of ink introduced to the waste ink reservoir 10 is still small, the outer shape of the ink absorber 11 in the waste ink reservoir 10 does not swell so much and remains in the shape shown by the solid line in FIG. Therefore, as shown in the figure, there is a gap between the upper surface of the ink absorber 11 and the contact 12a.
The contacts 12a and 12b are electrically disconnected from each other. Therefore, the signal level of the signal line 11 connected to the CPU 17 is high level, and in response to this, the CPU 1
Since 7 keeps the output level to the signal line 13 high, the AND gates 18a and 18b are open.

Therefore, in this state, when the operator operates the operation unit (not shown) to perform the discharge recovery operation, and when the drive signal of the motor 15 is issued from the CPU 17 to the signal lines l4 and l5, the drive signal is the AND gate. It is guided to the motor driver 19 via 18a and 18b, whereby the motor 15
Is driven, and the suction operation is performed.

Next, when the amount of ink guided to the waste ink reservoir 10 and absorbed by the ink absorber 11 increases as the operation of the ejection recovery mechanism is repeated, the ink absorber 11 swells entirely. Therefore, the outer shape of the ink absorber 11 shows an increase in volume in the four surrounding directions and in the upward direction. Then, when the waste ink is sufficiently absorbed by the ink absorber 11 and the volume of the ink absorber 11 reaches a desired state close to full of the waste ink reservoir 10,
The outer shape of the ink absorber 11 swells as shown by the dotted line in FIG. 2, and its upper surface comes into contact with the contact 12a.

Therefore, the contacts 12a and 12b are electrically connected via the ink absorbed in the ink absorber 11, the signal line 11 is grounded via the contacts 12a and 12b and the signal line 12, and the CPU
The signal level of the signal line 11 for 17 changes from the high level to the low level.

In response to this, the CPU 17 changes the output signal to the signal line 13 from the high level to the low level, and the AND gates 18a and 18b are closed.

Therefore, in this state, the CP
The motor 15 guided from U17 to the signal lines l4 and l5
Since the drive signal of is cut off by the AND gates 18a and 18b, the motor 15 is stopped and the recovery operation is stopped.

After that, even if the drive signal is led again from the CPU 17 so as to perform the discharge recovery operation again, the same signal is applied to the AND gate 18
Since it is cut off by a and 18b, the recovery operation is prohibited and is not performed.

By the above operation, since the ink absorber 11 in the waste ink reservoir 10 has absorbed a predetermined amount of waste ink close to the ink absorbing capacity of the absorber, the ejection recovery operation is prohibited. No more waste ink is ejected than that of 10. Therefore, overflow of the waste ink from the waste ink reservoir 10 is reliably prevented. Further, since the ejection recovery operation is prohibited, the operator is informed that the waste ink reservoir 10 is almost full, so that the operator can know when to replace the waste ink reservoir 10.

[Second Embodiment] Next, the structure of a second embodiment of the present invention using a manual pump as the pump in the above structure will be described with reference to FIGS. 5 and 6. In this case, only the configuration of the pump and the control circuit described above is different. In the figures, parts that are the same as or correspond to those in FIGS. 3 and 4 are indicated by the same reference numerals or the same reference numerals with a dash added.

When the pump is manual, it is constructed as shown in FIG. 5 (A), for example. As shown in the figure, the pump lever 14 'for driving the piston 13' of the pump 8'is rotatably supported by the fulcrum 14'a at the tip, and can be manually rotated in the downward direction of the arrow in the figure. As a result, the pressing portion 14'b provided at the substantially central portion abuts against the tip of the shaft 13'a of the piston 13 'and presses it to lower the piston 13' to perform suction. A stopper 14'c is provided below the rear end portion of the pump lever 14 ', and a stop lever 20 is disposed below the stopper 14'c.

This stop lever 2 is bent in the shape of a crank
0 is rotatably supported by a shaft 21 at its central portion, and is urged clockwise in the figure by the urging force of a spring 23 mounted on the stop lever 20 via the shaft 21 and a stopper 22. There is. The rear end of the stop lever 20 is connected to the drive shaft of the plunger 24.

FIG. 5 (A) shows a state in which the coil of the plunger 24 is not excited, and the stop lever 20 pulls out the drive shaft of the plunger 24 by the urging force of the spring 23 and rotates clockwise, and the outside of the tip end portion is It is in a position where it abuts against the stop 25 and stops. Here, the tip of the stop lever 20 is out of the rotation region of the stopper 14'c of the pump lever 14 ', and the pump lever 14' can be manually moved up and down to perform the suction operation.

When the coil of the plunger 24 is excited, its drive shaft is pulled into the plunger 24, the rear end of the stop lever 20 is pulled to the right in the figure, and the stop lever resists the urging force of the spring 23. And rotate counterclockwise,
It is displaced as shown in FIG. 5 (B).

At the position shown in the figure, since the tip of the stop lever 20 faces the stopper 14'c of the pump lever 14 ',
Even if you try to push down the pump lever 14 'manually,
The stopper 14'c abuts against the tip of the stop lever 20 and is blocked, the pump lever 14 'cannot be lowered any further, and the suction operation is prohibited and is not performed.

The coil 24a of the plunger 24 having the above structure is connected to the control circuit shown in FIG. The CPU denoted by reference numeral 17 'in the figure has the same function as that of the CPU of the above-described embodiment, but in this case, the signal level of the signal line 11 connected to the contact 12a of the waste ink reservoir 10 is changed. It monitors and outputs a signal having a level opposite to this signal level to the signal line 16.

The signal line 16 is connected to the base of a switching transistor 27 via a series connection of an inverter 26 and a resistor R2. This base is connected to the power supply Vcc via a bias resistor R3. Also transistor 27
The emitter of is also connected to the power supply. In addition, the collector of the transistor 27 has a coil 24 of the plunger 24 described above.
The parallel connection of a and the spike preventing diode 28 is connected, and one end of this parallel connection is grounded.

Next, the operation of this embodiment having the above configuration will be described.

As in the previous embodiment, when the amount of waste ink in the waste ink reservoir 10 is small, the ink absorber 11 hardly swells, so that the contacts 12a and 12b are blocked from each other, and the signal level of the signal line 11 changes. It is at a high level. In response to this, since the output signal level of the signal line 16 of the CPU 17 'is kept at the low level, the output side of the inverter 26 is at the high level and the transistor 27 is cut off. Therefore, since no current flows through the coil 24a, the position of the stop lever 20 is at the position shown in FIG. 5 (A). Therefore, the operation of the pump lever 14 'is not restricted,
This can be rotated in the vertical direction to drive the pump 8'and perform the suction operation.

By repeating the recovery operation, the waste ink reservoir 10
The ink absorber 11 in the inside absorbs the waste ink to a predetermined amount which is close to the full capacity of the ink absorbing capacity.
Swell and come into contact with the contactor 12a and contactor 12a, 12b
The two are electrically connected, and the signal level of the signal line 11 becomes low level. In response to this, the CPU 17 'changes the output of the signal line 16 to the high level, so that the output side of the inverter 27 changes to the low level and the transistor 27 becomes conductive.
As a result, a current is applied to the coil 24a of the plunger 24, and the plunger is driven. Therefore, the stop lever 20 is rotated to the position shown in FIG. 5 (B), and the tip of the stop lever 20 faces the stopper 14'c of the pump lever 14 'and abuts against it, so that the pump lever 14 cannot be pushed down.
Suction operation is prohibited.

Even with the above configuration, the same effect as that of the previous embodiment can be obtained.

[Third Embodiment] In the first and second embodiments described above, the swelling state of the ink absorber 11 in the waste ink reservoir 10 is detected via the contact, but other detecting means may be used. FIG. 7 shows the configurations of the waste ink reservoir and the optical detection means when the swelling state of the ink absorber is detected by the optical detection means.

In the configuration shown in the figure, the waste ink reservoir 10 'is formed of a translucent material into a substantially rectangular parallelepiped tank shape, and an ink absorber 11' having a shape substantially similar to that of the waste ink reservoir 10 'is provided therein. It is housed. A light emitting element 29 and a light receiving element 30 of an optical detecting means are arranged opposite to each other on the upper side and the lower side of the left end portion of the waste ink reservoir 10 '.

Here, the light emitting element 29 is composed of, for example, an LED, and the light receiving element 30 is composed of, for example, a phototransistor.

In the initial state before absorbing the waste ink, the ink absorber 11 'has the shape shown by the solid line in the figure, and there is a gap between its left side surface and the left inner wall surface of the waste ink reservoir 10'. The irradiation light of the light emitting element 29 is received by the light receiving element 30 through this gap, and the light receiving element 30 is conducting.

The ink absorber 11 'swells as it absorbs the waste ink, and when the amount of absorbed waste ink approaches the full ink absorption capacity of the ink absorber 11', its shape becomes the shape shown by the dotted line in the figure, and its left side surface The gap with the inner wall surface of the waste ink reservoir 10 'disappears, the irradiation light of the light emitting element 29 is blocked, and the conduction of the light receiving element 30 is blocked.

Therefore, depending on the level of the output signal of the light receiving element 30, the ink absorber 11 'stored in the waste ink reservoir 10' is
Absorbs a nearly full amount of ink with respect to the ink absorption capacity and can detect whether or not a predetermined swelling state has been reached.

The same effect can be obtained by combining the detecting means having the above configuration with the configurations of the first and second embodiments described above. Further, one or both of the light emitting element 29 and the light receiving element 30 of the optical detecting means may be provided in the waste ink reservoir 10 '.

[Effect] As is clear from the above description, according to the present invention, it is provided with the discharging means for discharging the ink from the recording head regardless of the recording operation, and the storage member for collecting and storing the discharged ink, In a recovery mechanism that recovers or maintains the ink ejection state of the recording head, the amount of ink that can be collected in the storage member is detected by using an ink absorber whose volume increases due to the recovery of the ink, and the recording head is Since it is possible to prohibit the ink discharge operation, it is possible to prevent the ink from overflowing from the storage member, and it is possible to reliably prevent inconveniences such as dirt in the recording device and damage to the electric circuit.

[Brief description of drawings]

1 to 4 illustrate a first embodiment of the present invention. FIG. 1 is a schematic configuration diagram of an ink supply system and an ejection recovery mechanism of an inkjet printer to which the present invention is applied, and FIG. 1 is a vertical sectional view of a waste ink reservoir in FIG. 1, FIG. 3 is a schematic configuration diagram of the pump and its drive system in FIG. 1, FIG. 4 is a block circuit diagram of a control circuit, FIG. 5 and FIG. FIG. 5 illustrates a second embodiment of the present invention. FIGS. 5 (A) and 5 (B) are schematic configuration diagrams illustrating the configuration and operation of a pump and its braking mechanism, and FIG. 6 is a control circuit. Block circuit diagram of
FIG. 7 is a vertical cross-sectional side view showing the configurations of the waste ink reservoir and the detecting means according to the third embodiment of the present invention. 8,8 '... Pump 10, 10' ... Waste ink reservoir 11, 11 '... Ink absorber 12a, 12b ... Contactor 14, 14' ... Pump lever 15 ... Motor, 17, 17 '... ... CPU 20 ... stop lever, 24 ... plunger 29 ... light emitting element, 30 ... light receiving element

Claims (1)

[Claims] 1. A recovery for recovering or maintaining an ink ejection state of the recording head, comprising: a discharging unit for discharging ink from the recording head regardless of a recording operation; and a storage member for collecting and storing the discharged ink. In the mechanism, while accommodating an ink recovery member, the volume of which is increased by recovering the discharged ink, in the storage member,
A detection unit that detects that the ink recovery member has increased to a predetermined volume; and a control unit that receives a detection signal from the detection unit and performs control to prohibit the ink discharge operation of the discharge unit. Recovery mechanism characterized by.