JP2700580B2 - Ink jet recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus that forms an image by ejecting ink droplets from ejection openings of a recording head and attaching the ink droplets to a recording sheet. The present invention also relates to an ink jet recording apparatus provided with a recovery device for resolving an ink ejection failure of the recording apparatus.

[Conventional technology]

A recording device such as a printer, a copier, and a facsimile drives an energy generator of a recording head on the basis of transferred image information to form an image formed of a dot pattern on a recording sheet such as paper or a plastic thin plate. It is configured to record.

The recording apparatus can be classified into an ink jet type, a wire dot type, a thermal type, a laser beam type, and the like according to a recording method. Among them, the ink jet type (ink jet recording apparatus) discharges ink from a discharge port of a recording head. The recording is performed by attaching the recording sheet to a recording sheet.

2. Related Art In an ink jet recording apparatus, a recording liquid (ink) droplet is ejected and ejected from an ejection port of a recording head, and adheres to a recording medium such as a sheet to perform recording.

However, if the non-printing state continues, the ink in the ejection openings may be fixed, and even if a recording signal is generated, the ink may not be normally ejected from the ejection openings.

Therefore, a recovery device is used as a means for eliminating the sticking of the ink in the discharge port. There are two types of the recovery device, a pressurization type and a suction type.

The pressurizing type presses a part of the ink supply system of the recording head to forcibly push out the ink from the ejection port of the recording head, thereby eliminating clogging due to ink fixation.

On the other hand, in the suction type, the front surface (ejection surface) of the recording head where the ejection openings are formed is sealed with a cap, and the inside of the cap is sucked to suck out ink from the ejection openings. Pumps are used.

 The prior art will be described for this suction type.

This suction type recovery device is configured such that the discharge port surface of the recording head is sealed with a cap made of an elastic member such as rubber, and the inside of the cap and a suction pump are connected by a tube, and the suction pump is operated. Then, the ink is sucked out from the ejection port to thereby solve the ink ejection failure.

In this case, the recovery capacity of the recovery system is determined by the suction capacity of the pump, that is, how large a negative pressure is generated.

FIG. 9 is a longitudinal sectional view showing an example of the suction pump.

In FIG. 9, a pump 1 comprises a cylinder 2 and a piston 3
The O-ring 4 is attached to the piston drawing hole of the cylinder 2.

The illustrated cylinder 2 is configured by integrating a cylinder 2a and a lower cylinder 2b by welding or the like.

The cylinder 2 is fixed to a recovery base 7 with a screw 5 via a seal 6.

The piston 3 includes a central shaft portion and a piston portion on which a piston ring 8 is mounted. A parallel pin 9 is press-fitted into an upper portion of the shaft portion, while an O-ring 10 is fitted into a lower portion of the shaft portion. A groove is provided in which an O-ring 10 is mounted.

Spaces G and H defined by the piston portion are defined inside the cylinder 2.

The piston 3 is rotated by the rotation of the pump cam 11,
When the parallel pin 9 slides along the pump cam groove 11a, the parallel pin 9 reciprocates in the vertical direction (I direction).

Although the piston ring 8 and the cylinder 2 slide through silicon grease, ink is also attached to the wall surface of the cylinder 2. Therefore, when the ink is solidified after being left for a long time, the piston ring 8 is attached to the cylinder 2. There is a case where the piston 3 is fixed and cannot slide. This sticking force is 10kg
Therefore, in order to prevent the piston from sticking, it is necessary to use a positive cam that slides the piston 3 reliably.

When the suction pump 1 operates, the space G increases and the space H decreases when the piston 3 moves downward. At this time, since the pressure in the space G becomes lower than the atmospheric pressure and becomes a negative pressure, ink flows from the inlet 2c of the cylinder 2 and the space H
Is higher than the atmospheric pressure, the ink existing in the space H is discharged from the outlet 7a as waste ink.

At this time, a valve (not shown) provided on the piston 3 is in a closed state.

On the other hand, when the piston 3 moves upward, the inlet 2c
Is in a position immediately closed by the piston ring 8, the pressure in the space G increases.

On the other hand, the pressure in the space H is lower than that in the space G, but since the space H is open to the atmospheric pressure through the outlet 7a, the pressure in the space H is maintained at the atmospheric pressure.

Therefore, the valve that opens and closes the pores of the piston portion of the piston 3 is opened, and the ink flows from the space G to the space H.

The suction capacity of the suction pump 1 is determined by how to increase the negative pressure in the space G.

[Technical problem to be solved by the invention]

However, in the suction pump of the recovery device of the conventional ink jet recording apparatus, the piston 3 has the piston ring 8
By sliding the inner wall surface of the cylinder 2 through the nozzles, a negative pressure and a positive pressure are generated in the cylinder 2 so that the ink is sucked from the recording head and then discharged.

Here, it is necessary to make the cylinder 2 and the piston ring 8 adhere to each other so that the negative pressure and the positive pressure do not leak.

Therefore, the piston ring 8 is made of rubber (for example, NB
R), using the deformation to seal.

However, when the deformation is large and the sliding resistance is large, the torque loss is large. Therefore, vacuum grease is actually applied between the cylinder 2 and the piston ring 8. When the grease and the ink are mixed, the piston ring 8 adheres to the wall of the cylinder 2, and about 10 kg of force is required on the shaft of the piston 3 to release the adhesion.

Therefore, in the conventional ink jet recording apparatus, the gear reduction ratio is increased and the torque is set to a large value so that this degree of piston sticking can be released.

That is, the speed reduction ratio has been determined on the assumption of the worst case in which the frequency of the pump 1 sticking is low.

On the other hand, in the normal state where the pump does not stick, the piston 3
The pump works satisfactorily with about 3 kg of force on the shaft.

For this reason, in the suction pump of the conventional recovery device, the suction pump is driven with a torque approximately three times as much as a normally required torque.
The gear train and the like were configured.

Therefore, in the recovery device of the conventional ink jet printing apparatus, there is a waste of electric power consumed for driving the pump 1, and moreover, it takes much time to complete the recovery operation, and the printing speed is reduced. was there.

The present invention has been made in view of the above-mentioned conventional technical problems, and can reduce the power consumption required for driving the pump of the recovery device, shorten the recording recovery time, and improve the recording speed. An object of the present invention is to provide an ink jet recording apparatus capable of improving cost performance.

[Means for solving the problem]

The present invention relates to an ink jet recording apparatus having a recovery device, wherein a pump constituting the recovery device is fixed.
The configuration for performing the control to increase the torque of the driving means can reduce the power consumption required for driving the pump of the recovery device, shorten the recording recovery time, improve the recording speed, and improve the cost performance. An object of the present invention is to provide an ink jet recording apparatus.

In the above configuration, it is preferable to use a pulse motor as the driving unit and variably control the pulse rate of the pulse motor.In actual control, the pulse motor is initially driven at a high pulse rate. ,
When it is determined that the pump is stuck, it is preferable to reduce the pulse rate, and when it is determined that the pump is normal, it is preferable to drive at the original fast pulse rate.

Further, a similar effect can be obtained by a control mode in which the voltage of the driving means is increased when the pump is stuck.

〔Example〕

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a perspective view showing a recovery device of an ink jet recording apparatus according to the present invention. Reference numeral 12 denotes an ink jet recording head, for example, which uses thermal energy to eject and fly ink as small droplets and adheres them to a recording sheet to form an image.

Reference numeral 13 denotes a carriage to which the recording head 12 is fixed. The carriage 13 is mounted on the carriage shaft 14 while moving the carriage shaft 14 left and right by a timing belt integrated with the carriage motor and the carriage 13 (not shown). The recording head 15 is configured to scan the recording sheet 15 and perform recording.

Reference numeral 16 denotes a pinch roller stay that rotates around an axis (not shown) in accordance with the thickness of the recording sheet 15;
Part 13 slides on the pinch roller stay 16 under its own weight, thereby maintaining the gap between the surface of the recording sheet 15 and the recording head 12 constant regardless of the thickness of the recording sheet 15. Thus, the quality of the recorded image is maintained.

The recovery device is provided to discharge the ink droplets from the discharge ports of the recording head 12 in a stable and appropriate state.

When recording is not performed for a certain period of time, the recording head 12 seals the ejection port surface of the recording head 12 with a cap 17 in order to prevent non-ejection of ink due to sticking of ink in the ejection port.

FIG. 2 is an exploded perspective view of the cap 17, and the cap 17 is held by a cap holder 18 as shown in FIG.
The cap holder 18 is held by a holder 19.

A cap spring 20 for pressing the cap 17 against the recording head 12 with an appropriate force is provided between the cap holder 18 and the holder.
The claw portion 18a of the cap holder 18 is inserted into the hole portion 19a of the holder 19 and is patched.

The dowels 18b on both sides of the cap holder 18
The cap holder 18, which enters the groove 19b and is integrated with the cap 17, swings with the dowel 18b as a fulcrum according to the ejection opening surface of the recording head 12.

There are two dowels 19c above and below the holder 19.
By fitting 9c into the U groove 21a of the slider 21,
The cap unit is completed.

The cap holder 18 and the holder 19 are movable in the direction of arrow A, and the holder 19 and the slider 21 are movable in the direction of arrow B. Therefore, the cap 17, the cap holder 18, and the holder 19 are held by the slider 21, and the carriage 17
When the carriage 13 moves along the carriage shaft 14 from the recording unit toward the recovery device, the dowel 13a (first
(Fig.) Enters the hole 21b of the arm portion of the slider 21.

Therefore, the slider 21 moves along the slide shaft 22,
It moves to the left in FIG. 1 together with the carriage 13. At this time, the roller 23 inserted in the dowel portion 19c of the holder 19
While rolling around the slot 24a of the flat cam 24,
The holder 19 projects toward the recording head 12 and the slider
21 moves to the left.

As a result, the cap 17 is pressed against the ejection opening face of the recording head 12.

 The pressing force at this time is about 300 to 500 g.

FIG. 3 is a cross-sectional view of the air communication port of the cap 17, and FIG.
Is brought into contact with the stopper 25 with a pressing force of about 100 g by a mechanism described later.

This contact closes the atmosphere communication hole 17b, and at the same time, the large recovery cap tube 26 is closed by means described later, so that the large recovery hole 17c is also closed.

FIG. 4 is a perspective view of the recovery device when the flat cam unit is removed. In FIG. 4, the waste ink cap tube 27 is connected to a pump 28.
When the piston 29 moves in a predetermined direction, a negative pressure is generated inside, and the pressure inside the cap 17 pressed against the recording head 12 also becomes negative.

For this reason, ink is forcibly sucked from the ejection port of the recording head 12 and dust and a fixed ink layer in the ejection port are removed by the cap 17.
The ejection failure state of the recording head 12 is eliminated.

When the piston 29 that has reached the bottom dead center moves in the direction of the recording head due to a cam movement described later, the inside of the pump 28 is in a pressurized state, and the ink sucked from the cap 17 is discharged into the waste ink tube 30 (FIG. 1). ) Is discharged from the waste ink inlet 31a to the waste ink reservoir of the ink cartridge 31 (FIG. 1).

When the waste ink is discharged, there is no pressure change on the cap 17 due to the structure of the pump. In such a state, the ink sucked from the ejection port of the recording head 12 is still in the cap 17.
And remains in the waste ink cap tube 27. Therefore, ink adheres to the ejection port surface of the recording head 12, and
Due to the adhered ink, if the surface tension of the ink is greater than the ink ejection force, non-ejection of ink may occur, or the recording sheet 15 may be stained by scattering of ink at the time of contact of the blade 32, which will be described later. May be invited.

In order to solve such a problem, in the following sequence, in order to remove the ink in the cap 17 and the ink adhered to the ejection opening surface of the recording head 12, the cap 17 is pressed in a state where the cap 17 is in pressure contact with the recording head 12. Air valve
The carriage 13 is slightly moved to the right (2 mm in this embodiment) so as to release the contact of the stopper 17a with the stopper 25.

By operating the suction pump in this state, since the atmosphere communication hole 17b is formed above the cap 17 in an L shape as shown in FIG. 3, air is sucked into the cap 17 through the atmosphere communication hole 17b, Further, air flows from the upper side of the cap 17 to the lower side where the waste ink cap tube 27 is attached. Therefore, the ink in the cap 17 and the ink adhered to the ejection port surface of the recording head 12 are removed.

Thereafter, the discharge port surface of the recording head 12 is rubbed by the rubbing member 33 by moving the carriage 13 from left to right while the rubbing member 33 is projected by means to be described later. By removing ink and stains on the surface, the ejection stability of the recording head 12 is ensured.

FIG. 5 is an exploded perspective view of a rubbing mechanism including the rubbing member 33. In the same figure, the rubbing mechanism is such that a ring-shaped rubbing member 33 is fitted to an oval-shaped rubbing inserter 34, and a rubbing inserter 34 is provided. To the rubbing holder 35, and furthermore, rub the slider 35 with the rubbing holder 35 via the rubbing spring 36.
It is attached by mounting.

The rubbing inserter 34 is mounted on the rubbing holder 35 by patching the dowels 34a into the U-grooves 35a.

In addition, the rubbing holder 35 has a dowel claw 35b with a hole 37a.
Is mounted on the rubbing slider 37.

Thus, the rubbing member 33 is movably mounted in the direction D.

The protrusion of the rubbing slider 37 is performed by a cam described later, and the return to the original position is performed by a part 37b of the rubbing slider 37.
This is performed by using the restoring force due to the elastic deformation.

Here, when the cam comes into contact with the dowel portion 37c of the rubbing slider 37, the rubbing member 33 projects.

The rubbing member 33 is made of, for example, an ether-based polyurethane continuous pore body.

Further, a blade 32 is provided between the rubbing member 33 and the cap 17.
If paper dust or other dust adheres to the discharge port surface during recording, the paper 32 is wiped off with a blade 32 before being rubbed by the rubbing member 33, thereby stabilizing the discharge of the recording head 12. It is configured to ensure the performance.

The blade 32 uses a flexible silicon rubber having a wall pressure of about 0.3 to 0.5 mm.

The blade 32 is attached to a part of the base 40 of the recovery device by a blade retainer 39, and always protrudes.
A wiping by 32 is performed.

During recording, the slider 21 is returned to the right by the slide spring 41 as shown in FIG. 4, and the cap 17 is moved to a position determined when a part of the slider 21 abuts a part of the base 40 of the recovery device. Will be retained.

The blade 32 is held on the base 40 of the recovery device while being held down by the blade holder 39.

On the other hand, during printing, the recording head 12 returns to the position held by the cap 17 to prevent the ejection ports that are not used in the ejection ports of the recording head 12 from sticking, and determines that all the ejection ports are idle. It is configured to be performed every given time.

When the recording head 12 reciprocates at this time, wiping by the blade 32 is performed. Of course, when the recovery operation is performed, the wiping by the blade 32 is performed. Here, when the idle discharge is performed, the dowel 19c of the holder 19 is in the groove 24a of the flat cam 23.
, The cap 17 and the recording head 12 are separated from each other, and the ink that has been ejected idle is
It is absorbed and held by the polymer absorber inside, and is sucked toward the pump 28 when the pump 28 is operated later.

When the dowel portion 13a of the carriage 13 enters the hole 21b of the arm of the slider 21, the dowel 19c of the holder 19 is moved to the slot 24a of the flat cam 24 with the movement of the carriage 13 to the left.
The cap 17 is pressed against the recording head 12 by climbing the inclined surface of.

 Next, the cam operation will be described.

The sheet feed motor of the recording apparatus exhibits a sheet feed function during normal rotation.

On the other hand, at the time of reverse rotation, the sheet feed roller shaft 43 and the recovery device drive gear 44 rotate integrally in the direction of the arrow E by the clutch spring 45, and the cam gear 47 rotates via the idle gear 46, and the With the cam shaft 48, the rubbing cam 49,
The pump cams 50 and 51 and the home position cam 52 rotate.

The pump cams 50 and 51 are positive-acting cams. Grooves are formed on opposite surfaces of the pump cams 50 and 51 so that both ends of a parallel pin 53 integrally connected to the piston 29 of the pump 28 are slidably engaged. A parallel pin 53 is slid by the rotation of the pump cams 50 and 51 to operate the piston 29.

When the power is turned on, the recovery device drive gear 44 rotates, the home position cam 52 also rotates, and the home position switch 54 is turned on.
The signal turns ON, and the cam group is initialized.

The above-mentioned recovery operation is called a small recovery, and is performed when the non-ejection can be easily eliminated. However, when the non-ejection cannot be easily eliminated due to the fixation of the ejection port of the recording head 12, a recovery operation called a large recovery is performed. Done.

The position of the recording head 12 at the time of the large recovery is a position moved 2 mm to the left as compared with the time of the small recovery, and at this position, the air valve 17a of the cap 17 is maintained in a closed state.

FIG. 6 is an exploded perspective view of the flat cam unit.
Next, the configuration and operation of the large recovery mechanism will be described with reference to FIG.

In FIG. 6, the stopper 25 can be smoothly slid in the moving direction of the carriage 13 by a part 24b of the flat cam 24.
The protrusion 25a of the stopper 25 is fitted and mounted in the groove 55a.

The fulcrum 55b of the stopper lever 55 is fitted to the dowel 24c of the flat cam 24. Further, a large recovery valve 56 is attached to a part 24b of the flat cam 24, and the large recovery valve 56 is provided with a hole 56a and a thin hole 56b56c.
6b and 56c are in communication. The communicating holes 56b, 56c
Is opened and closed by a valve piston 57.

A large recovery spring 58 is mounted between the valve piston 57 and the hole 55c of the stopper lever 55, and the valve piston 57 enters the U groove 55d of the stopper lever 55.

A stopper spring 59 enters the fulcrum 55b of the stopper lever 55, one end 59a of the stopper spring 59 abuts on a hook portion (not shown) of the flat cam 24, and the other end 59b abuts a part 55e of the stopper lever 55. I have. Therefore, a restoring force when the stopper 25 moves to the left can be obtained.

With such a mechanism, the valve piston 57 and the inner wall of the hole 55c of the stopper lever 55 are not in contact with each other when the small recovery pump operates, and the valve piston 57 is pressed against the large recovery valve 56 by the large recovery spring 58. And the small holes 56b and 5 of the large recovery valve 56
6c is not communicating.

When the carriage 13 moves leftward by 2 mm for a large recovery operation from this state, the inner wall of the hole 55 of the stopper lever 55 comes into contact with the valve piston 57, and the valve piston 57 comes into contact with the large recovery valve 56.
The small holes 56b and 56c communicate with each other to move in the direction of coming out of the hole.

Therefore, ink can be supplied from the ink cartridge to above the cap 17 by a tube described later.

Here, the arrangement of the ink tubes will be described with reference to FIG.

An ink outlet 31b is provided at the upper part of the ink cartridge 31, and a three-way joint 60 is provided in the ink outlet 31b.
An ink supply tube 61 is connected between one of the ports and a sub-tank (not shown) on the carriage 13, and the sub-tank is connected to the recording head 12 by a tube (not shown).

A sub tank tube 62 from a part of the sub tank is connected to the ink suction port 28b of the pump 28.

As described above, the thin hole 56c of the large recovery valve 56 and the cap 17 are connected by the large recovery cap tube 36, and the thin hole 56b of the large recovery valve 56 and the three-way joint 60 are connected by the large recovery tube 63. The three-way joint 60 is connected to an ink outlet 31b of the ink cartridge 31.

The waste ink of the pump 28 is part 40 of the base 40 of the recovery device.
The ink cartridge 31 is collected by the ink cartridge 31 via the waste ink tube 30 connecting the ink cartridge 31 and the waste ink inlet 31a of the ink cartridge 31. The waste ink sucked from the lower side of the cap 17 by the pump 28 is supplied to the waste ink cap tube.
The ink is sucked into the ink suction port 28a of the pump 28 by the pump 27.

 The above is the description of each ink tube.

Therefore, at the time of large recovery, like at the time of small recovery,
Since the cap 17 is pressed against the ejection port surface of the recording head 12, the ink moves into the cap 17 from the large recovery hole 17c when the piston 29 of the pump 28 moves in a predetermined direction, and at the same time, the ejection of the recording head 12 starts. Ink from the outlet also flows into the cap 17, and these inks are discharged by the pump 28 toward the waste ink reservoir.

After the pump operation is performed four times to collect ink in the sealed space between the cap 17 and the ejection opening surface of the recording head 12, the recording head 12 is moved rightward by 2 mm.

This movement causes the stopper spring 59 of the stopper lever 55 to move.
By returning the valve piston 57 to its original position,
The flow path of the large recovery valve 56, that is, the small holes 56b and 5 of the large recovery valve 56
6c is closed.

In this state, the ink is held for about one minute to soften the ink by adding the ink to the fixed ink, and then the pump is operated to discharge the ink in the space between the cap 17 and the ejection opening surface of the recording head 12. At the same time, the ink is sucked and discharged from the ejection port of the recording head 12.

Next, by moving the recording head 12 further to the right by 2 mm, the air communication hole 17b of the air valve 17a of the cap 17 is opened, and the pump 28 is operated.
The ink between the ejection opening face 12 and the cap 17 is removed.

In this way, the air flows through the air communication hole 17b, and the air is introduced into the waste ink discharge port 17d of the cap 17.

 The above is the large recovery operation.

In addition, the above-mentioned recovery devices are dowels 40b and 4 of the base 40.
By patching 0c to the recording apparatus main body, it can be easily attached.

The flat cam 24 and the base 40 of the recovery device are patched by mutual claws.

FIG. 7 is a graph showing the characteristics of the pulse rate and the torque of the motor for driving the recovery device of the ink jet recording apparatus according to the present invention.

In FIG. 7, the characteristic curve of the pulse motor shows the characteristic as shown if the X axis is a pulse rate [PPS] and the Y axis is a torque [gcm].

In this graph, the required torque is To when the pump 28 is normal without sticking and the pulse rate at that time is No.
The torque required when the pump 28 is stuck is indicated by T ₁ , and the pulse rate at that time is indicated by N ₁ .

Therefore, in the inkjet recording apparatus of the present invention, the drive source (pulse motor) for the recovery device is a pump 28
Normal operation without sticking Normally pulse rate No
It is operated at [PPS], and when sticking occurs, it is operated at pulse rate N ₁ [PPS].

FIG. 8 is a flowchart of the motor control described with reference to FIG. 7 when the pump 28 is stuck and becomes abnormal.

In FIG. 8, when the pulse motor is started, first, in step S1, the motor is driven at the initial setting condition, that is, at the initial high pulse rate No.

This initial setting condition is home position cam (HP)
A pulse signal of more than one rotation of 52 is given.

In the next step S2, it is determined whether or not the home position switch 54 is on.

Be driven by this fast pulse rate N _0, if not the home position switch 54 is turned on, it is assumed that the pump 28 is stuck, the then proceeds to step S3,
Slow pulse rate of the pulse rate N ₁ home position cam 52 gives more pulse signals one rotation.

In step S4 the home position switch 54, it is determined whether or not turned on, it is determined if the above-described slow pulse rate N ₁ fixed time driving to the home position switch 54 also does not turn on, an error in step S5 alarm Display.

If the home position switch 54 is turned on in step S2 or step S4, the process proceeds to step S6, the return faster values N ₀ of the original pulse rate, to perform a sequence of recovery operation while driving the pump 28 at a faster rate.

As described above, when the pump 28 is stuck, once the speed of the pulse motor is reduced and the torque output is increased, the stuck of the pump 28 is eliminated (recovery) and the step-out of the motor is also eliminated. The rate rapidly changes to the original value N ₀
, And the recovery device operates normally.

That is, if the operation once depleted sliding resistance of the pump 28, the load on the axis of the piston 29 is about 3 kg, the current sequence after the end of the pump 28 at a faster rate of the original pulse rate N ₀ It drives and controls the recovery device.

Thus, the sequence of the recovery operation ends in step S7.

In the conventional ink jet recording apparatus, as described above, the reduction ratio is always increased in consideration of the load when the pump is fixed, the pulse rate of the pulse motor is reduced, the pump 28 is driven at a low speed, and the recovery device is operated. Therefore, even in a normal state in which the pump 28 is not fixed, a long time is required to complete the sequence of the recovery device, the actual recording speed is reduced, and the throughput is low.

On the other hand, according to the present invention, as in the above embodiment, if the pump 28 is stuck, the pulse motor loses synchronism. Therefore, the home position switch 54 detects the pump stuck, and the pulse motor When the pulse is turned on when the recovery operation is performed at a reduced rate and the operation returns to normal or returns to normal, the pulse rate is returned to the original fast value.
By returning to No, the recovery operation is performed with low torque operation, so that the power consumption required for driving the pump of the recovery device can be reduced, the recording recovery time can be shortened, the recording speed is improved, and the cost performance is improved. The resulting inkjet recording device was obtained.

As described in detail above, the motor is first driven by giving a fast pulse rate No.
Is turned on, the recovery sequence is continuously performed under the control of the pulse rate No.

On the other hand, if not the home position switch 54 is turned on, it is determined that the pump fixing, Yari lowering the pulse rate N _1, the pulse rate after the pump fixing is eliminated home position switch 54 is turned on The pump 28 is driven by returning to the fast value No.

In this way, always compared with the conventional recording apparatus running recovery sequence the pulse rate by assuming the worst itself as a slow value N _1, it is possible to recover the sequence early terminated, the recording speed By improving, an ink jet recording apparatus with high cost performance could be provided.

Note that the present invention is not limited to a pulse motor, and can be implemented in an ink jet recording apparatus using another motor such as a DC motor as a drive source of a recovery device. Is increased.

Even with such voltage control, the same effect as in the case of controlling the pulse rate as in the above-described embodiment could be achieved.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, in the ink jet recording apparatus having the recovery device, when the pump constituting the recovery device is stuck, control is performed to increase the torque of the driving means. The power consumption required to drive the recovery device pump can be reduced,
There is provided an ink jet recording apparatus capable of shortening a recording recovery time, improving a recording speed, and improving cost performance.

According to the second and third aspects of the present invention, in addition to the above configuration, a pulse motor is used as the driving means, and the pulse rate of the pulse motor is variably controlled. When the pump is determined to be stuck, the pulse rate is slowed down, and when the pump is determined to be normal, the pump is driven at the original fast pulse rate. Thus, an ink jet recording apparatus which can be executed quickly and accurately is obtained.

According to the fourth aspect of the present invention, in addition to the above configuration, when the pump is stuck, a control mode of increasing the voltage of the driving means is employed. Therefore, even in the ink jet recording apparatus using a motor other than the pulse motor, The recovery sequence can be easily and reliably executed by voltage control.

[Brief description of the drawings]

FIG. 1 is a perspective view of an essential part showing an embodiment of an ink jet recording apparatus according to the present invention, FIG. 2 is an exploded perspective view of a cap unit in FIG. 1, and FIG. 3 is a longitudinal section of the cap in FIG. FIG. 4 is a perspective view showing the recovery device in FIG. 1 with the flat cam unit removed, FIG. 5 is an exploded perspective view of the rubbing unit in FIG. 1, and FIG. 6 is a drawing in FIG. FIG. 7 is a graph showing the relationship between the pulse rate and the torque of the pulse motor, FIG. 8 is a flow chart at the time of controlling the pulse rate of the drive motor of the recovery device in FIG. 1, and FIG. FIG. 9 is a longitudinal sectional view of the pump in FIG. 12 Recording head, 15 Recording sheet, 17 Cap, 28 Pump, 29 Piston, 44 Recovery drive gear, 50, 51 Pump cam, 52 Home position cam, 54 ...... Home position switch.

Claims (4)

(57) [Claims] In an ink jet recording apparatus having a recovery device, when a pump constituting the recovery device is fixed,
An ink jet recording apparatus for performing control for increasing a torque of a driving unit. 2. The ink jet recording apparatus according to claim 1, wherein a pulse motor is used as the driving means, and a pulse rate of the pulse motor is variably controlled. 3. The pulse motor is initially driven at a high pulse rate, and if the pump is determined to be stuck, the pulse rate is reduced, and if the pump is determined to be normal, the pulse motor is driven at the original high pulse rate. The ink jet recording apparatus according to claim 2, wherein 4. The ink jet recording apparatus according to claim 1, wherein the voltage of the driving means is increased when the pump is stuck.