JP2023059344A - Cleaning device and printer - Google Patents

Abstract

To provide a cleaning device capable of being miniaturized.SOLUTION: A cleaning device 3 comprises a sheet-like web 32 for wiping an ink jet head, and a spray head 50 for spraying a cleaning liquid on the web 32 by turning it into a mist state by high-frequency oscillations.SELECTED DRAWING: Figure 5

Description

The present disclosure relates to cleaning devices and printing devices.

Conventionally, as disclosed in Japanese Unexamined Patent Application Publication No. 2004-167488 (Patent Document 1) and Japanese Unexamined Patent Application Publication No. 2012-176545 (Patent Document 2), an inkjet head of an inkjet printing apparatus (recording apparatus) is cleaned. A cleaning device (wiping unit) is disclosed. In such a cleaning device, while the web is moving, high-pressure air (or gas) is used to spray the cleaning liquid onto the web from the cleaning liquid spray head. The web sprayed with the cleaning liquid wipes the ink ejection surface of the inkjet head.

Japanese Patent Application Laid-Open No. 6-7720 (Patent Document 3) discloses an ultrasonic atomization device that drives a composite body composed of a piezoelectric vibrator and a vibrator that contacts a liquid retaining agent. In this ultrasonic atomizer, the liquid in the liquid retaining agent is atomized through holes provided in the vibrator when the composite is driven.

JP-A-2004-167488 JP 2012-176545 A JP-A-6-7720

When the cleaning liquid is sprayed onto the web from the spray head using high-pressure air (or gas) as in Patent Documents 1 and 2, it is difficult to miniaturize the cleaning device.

An object of the present disclosure is to provide a cleaning device that can be downsized, and a printing apparatus that includes the cleaning device.

According to one aspect of the present disclosure, the cleaning device includes a sheet-like web for wiping the inkjet head, and a spray head for spraying a mist of cleaning liquid onto the web by high-frequency vibration.

Preferably, the spray head is formed with a plurality of through-holes for misting the cleaning liquid.

Preferably, the area of the opening of each through-hole is 1 μm ² or more and 10000 μm ² or less.

Preferably, each opening is circular. The diameter of each opening is 1 μm or more and 100 μm or less.

Preferably, the spray head is formed with 10 or more and 10000 through-holes per 1 cm ² .

Preferably, the spray head sprays the cleaning liquid downward from the horizontal through the plurality of through holes. The spray head is installed near the position where the inkjet head is wiped.

Preferably, the spray head includes a vibrator having a plurality of through holes.
Preferably, the vibrator has a diaphragm with a plurality of through holes and a piezoelectric element that vibrates the diaphragm. The spray head further includes a porous body in contact with the diaphragm and impregnated with the cleaning liquid. The cleaning device further includes a drive circuit that drives the piezoelectric element at high frequencies.

Preferably, the piezoelectric element has a hollow cylindrical shape and has a first end face of the hollow circle and a second end face opposite to the first end face. The second end face is closer to the porous body than the first end face. The diaphragm has a circular outer shape and is arranged to cover at least a portion of the second end surface of the piezoelectric element.

Preferably, the central portion of the diaphragm is convex toward the inner peripheral surface of the piezoelectric element. At least some of the plurality of through holes are formed in the central portion.

Preferably, the spray head has multiple transducers. A drive circuit individually controls the drive of the piezoelectric element of each vibrator.

Preferably, the cleaning device is built in a printing device, and in the printing device, a plurality of inkjet heads are arranged in a transport direction of paper for printing. Each vibrator is arranged side by side in the transport direction.

Preferably, the porous body has a first portion and a second portion having a smaller thickness in the through-hole direction than the first portion. The second portion is in contact with the diaphragm.

Preferably, the apparatus further includes a tank for storing the cleaning liquid and for supplying the cleaning liquid to the spray head. The level of the cleaning liquid in the tank is lower than the positions of the plurality of through holes.

Preferably, the drive circuit drives the piezoelectric element by any one of voltage control, frequency control and pulse width modulation control.

Preferably, the cleaning device further comprises an electrode pair that contacts the web impregnated with the cleaning liquid. The cleaning device detects the amount of cleaning liquid impregnated on the web based on the current flowing between the electrode pair. The drive circuit drives the piezoelectric element based on the detection result so that the amount of cleaning liquid impregnating the web approaches a predetermined amount.

Preferably, the spray head atomizes the cleaning liquid into a mist and sprays it onto the unused portion of the web. The cleaning device moves the unused portion sprayed with the cleaning liquid to a position for wiping the inkjet head.

According to another aspect of the present disclosure, a printing device includes an inkjet head and a cleaning device that cleans the inkjet head. The cleaning device includes a sheet-like web for wiping the inkjet head, and a spray head for spraying the web with a mist of cleaning liquid by high-frequency vibration.

According to the present disclosure, it is possible to reduce the size of the cleaning device.

1 is a diagram for explaining the overall configuration of a printing device; FIG. 2 is a side view showing the printing apparatus of FIG. 1 from the direction of arrow II; FIG. FIG. 2 is a top view showing the printing apparatus of FIG. 1 from the direction of arrow III; 3 is a block diagram for explaining the hardware configuration of the cleaning device; FIG. 3 is a schematic diagram for explaining the hardware configuration of the cleaning device; FIG. It is a perspective view of a cleaning liquid supply device. 4 is a perspective view of a spray head of the cleaning liquid supply device; FIG. FIG. 7 is a bottom view showing the cleaning liquid supply device of FIG. 6 from the direction of arrow VIII; FIG. 8 is a plan view of the vibrator of FIG. 7 viewed from the direction of arrow IX; FIG. 10 is a cross-sectional view taken along line XX of FIG. 9; FIG. 2 is an enlarged view of a main portion of a diaphragm; FIG. 12 is a cross-sectional view taken along the line XII-XII of FIG. 11; 4 is a circuit diagram of a head drive circuit of the cleaning device; FIG. 4 is a schematic diagram schematically showing the operation of the head driving circuit; FIG. It is a schematic diagram for explaining the hardware configuration of a modification of the cleaning device. It is a figure for demonstrating a platen. FIG. 10 is a diagram for explaining a head driving circuit of another cleaning device; FIG. 4 is a diagram showing the relationship between setting switches and the output of a vibrator; 4 is a flow chart for explaining the control structure of the cleaning device; FIG.

A printing apparatus according to an embodiment will be described below with reference to the drawings. In the embodiments described below, the same reference numerals are given to the same parts and equivalent parts, and redundant description may not be repeated.

<A. Overall Configuration of Printing Apparatus>
The printing apparatus according to the present embodiment is an inkjet printing apparatus (recording apparatus). Typically, the printing apparatus is a production printing machine used in fields such as commercial printing and in-house printing.

FIG. 1 is a diagram for explaining the overall configuration of a printing apparatus according to this embodiment. FIG. 2 is a side view showing the printing apparatus of FIG. 1 from the direction of arrow II. FIG. 3 is a top view showing the printing apparatus of FIG. 1 from the direction of arrow III.

As shown in FIG. 1 , the printing apparatus 1 includes a paper conveying device 2 , a cleaning device 3 , a head standby section 4 , a controller 9 , an inkjet head station 10 , and a head moving device 11 . The printing apparatus 1 has a plurality of head stations 10, details of which will be described later.

The cleaning device 3 has a backup roller 31 . The head standby section 4 has a cap 41 and a waste liquid tank 42 . The head standby section 4 has a plurality of caps 41 , details of which will be described later.

The paper conveying device 2 has a conveying belt 20, a driving roller 21, and a driven roller 22 (FIG. 2). The paper 900 is transported by the transport belt 20 .

A head station 10 is fixed to a head moving device 11 . The head station 10 can move in the directions of arrows 990 (positive and negative directions of the X-axis) and in the directions of arrows 991 (positive and negative directions of the Z-axis) by moving the head moving device 11 .

A sheet conveying device 2 is arranged below the head station 10 . When the head station 10 moves in the direction of the arrow 990 , the cleaning device 3 and head standby section 4 are positioned below the head station 10 .

As shown in FIG. 2, when the head moving device 11 is directly above the sheet conveying device 2, the conveying belt 20 is rotated by the rotation of the driving roller 21 and the driven roller 22 in the arrow 992 direction. As a result, the paper 900 in close contact with the surface of the transport belt 20 is transported in the direction of arrow 993 . When the paper 900 passes through the head station 10 , ink is ejected from the head station 10 to form an image on the paper 900 .

Head station 10 is positioned on transport belt 20 for the duration of a series of print jobs. When the print job is finished, the head station 10 moves to a position where the cleaning device 3 waits and further a position where the cap 41 waits according to a command from the controller 9 (FIG. 1).

As shown in FIG. 3, the printing apparatus 1 has multiple head stations 10 . Specifically, the head moving device 11 has a plurality of head stations 10 for each ink type or color. Each head station 10 is arranged in a row in the Y-axis direction.

Each head station 10 has a plurality of inkjet heads 101 . Specifically, in this example, in each head station 10, the inkjet heads 101 are arranged in two rows so as to be able to print on the width of the paper.

A nozzle plate (not shown) is provided on the bottom surface of the inkjet head 101 . The nozzle plate is formed with a large number of nozzles through which a plurality of rows of ink are ejected. The inkjet head 101 is provided with piping (not shown) for ink supply and recovery.

The inkjet head 101 can supply and circulate ink through the pipe. Furthermore, the inkjet head 101 is provided with a device (not shown) for controlling the pressure applied to the ink. With this device, the inkjet head 101 forms an ink meniscus at the nozzle exit. During the purge process, ink is discharged from the nozzles by controlling the pressure.

A cleaning device 3 and a cap 41 are installed at corresponding positions (positions in the X-axis direction) of each head station 10 . In this manner, the printing apparatus 1 has as many cleaning devices 3 and caps 41 as the number of head stations 10 . In the printing apparatus 1 , maintenance of each head station 10 is performed by the cleaning device 3 and the cap 41 corresponding to the head station 10 .

Referring to FIG. 1 again, after the head station 10 executes a series of print jobs, the head moving device 11 moves the head station 10 directly above the cleaning device 3 . After that, the head moving device 11 moves downward (in the negative direction of the Z-axis). As a result, a cleaning member called a web (member to be brought into contact with and wiped) in the cleaning device 3 contacts a nozzle plate (not shown) on the surface of the inkjet head 101 .

Specifically, relative movement between the web and the head station 10 is caused by at least one of movement of the head moving device 11 in the X-axis direction (in this example, the positive direction of the X-axis) and movement of the web by the cleaning device 3. occur. This causes the nozzle plate to rub against the web. As a result, dirt such as ink adhering to the surface of the nozzle plate is removed.

When the head station 10 waits without executing a job, the head moving device 11 moves the head station 10 to a position facing the cap 41 . The cap 41 has a shape (container shape) that covers the head station 10 . A cap 41 seals the nozzle plate. The reason for the sealed state is to prevent bending (warping) and damage in the vicinity of the nozzles due to drying of the ink in the vicinity of the nozzles.

There is a space between the nozzle plate covered with the cap 41 and the bottom of the cap. This space is filled with a storage liquid or the like so as to keep it moist. The storage liquid may have any composition as long as it prevents the solvent of the ink from evaporating. Further, a waste liquid tank 42 is installed under the cap 41 so that a purge (ink ejection) process can be performed while the nozzle plate is covered with the cap 41 . A pipe (not shown) is provided on the bottom surface of the cap 41 . The printing apparatus 1 also has a mechanism for discharging the purged ink to the waste liquid tank 42 .

Note that the head moving device 11 can be moved to the cleaning device 3 after the purging process is completed, and the nozzle plate stained with the purged ink can be cleaned.

<B. Cleaning device>
(b1. Overall configuration)
FIG. 4 is a block diagram for explaining the hardware configuration of the cleaning device 3. As shown in FIG.

As shown in FIG. 4, the cleaning device 3 includes a web conveying device 30, a cleaning liquid supply device 5, and a head driving circuit 7. As shown in FIG.

The web transport device 30 includes a backup roller 31 , a drive roller 33 , transport rollers 34 a and 34 b , a web supply roller 35 , a web take-up roller 36 and a roller drive device 37 . The roller drive device 37 has a motor 38a, a motor drive circuit 39a that drives the motor 38a, a motor 38b, and a motor drive circuit 39b that drives the motor 38b.

The cleaning liquid supply device 5 includes a spray head 50 and a tank 54 . The spray head 50 includes multiple vibrators 51 . This example illustrates a case where the spray head 50 includes three vibrators 51 .

The head drive circuit 7 and the motor drive circuits 39 a and 39 b operate based on commands from the controller 9 . The operation of each hardware block of the cleaning device 3 will be described later.

FIG. 5 is a schematic diagram for explaining the hardware configuration of the cleaning device 3. As shown in FIG.
As shown in FIG. 5, the cleaning device 3 includes a web conveying device 30 and a spray head 50. As shown in FIG. The web 32 has a sheet shape. The web 32 is placed in the cleaning device 3 in a roll shape at the start of use.

Web 32 is fed from web feed roller 35 . The web 32 passes through the transport roller 34b, the backup roller 31, the transport roller 34a, and the driving roller 33 in this order, and is wound up by the web winding roller 36. As shown in FIG.

Movement (conveyance) of the web 32 is performed by the drive roller 33 . Drive roller 33 is a roller pair. A motor 38a (FIG. 4) is connected to one side of the drive roller 33 .

The web supply roller 35 rotates as the web 32 is pulled by the driving roller 33 . Thereby, the web 32 is supplied to the wiping position P. As shown in FIG. A torque limiter (not shown) is connected to the rotating shaft of the web supply roller 35 . In the cleaning device 3, the tension of the web 32 is stabilized by generating a constant dynamic friction force with a torque limiter. A torque limiter also prevents the web 32 from continuing to rotate due to inertia when stopped.

A motor 38 b ( FIG. 4 ) is connected to the rotation shaft of the web winding roller 36 . Furthermore, a torque limiter (not shown) is provided between the motor 38b and the rotating shaft of the web take-up roller 36. As shown in FIG.

A motor that drives the web wind-up roller 36 so that the surface speed of the web 32 wound up by the web wind-up roller 36 is faster than the actual transport speed of the web 32 (the transport speed of the web 32 by the transport rollers 34a and 34b). Set the rotation speed of 38b. By making such settings, regardless of the amount (thickness) of the web 32 wound up by the web winding roller 36, the transport speed of the web 32 and the surface speed of the web wound up by the web winding roller 36 are It becomes constant due to the action of the torque limiter.

The drive source for the driving roller 33 (motor 38a in this example) and the drive source for the winding roller (motor 38b in this example) may be the same motor.

The web 32 may be a woven fabric such as cotton or synthetic fiber, or a knitted fabric. Alternatively, the web 32 may be a non-woven fabric. When wiping the nozzle plate of the inkjet head 101 with the web 32, if the web 32 is moistened in advance with an appropriate liquid, the ink absorption performance (initial absorption speed) increases. Therefore, in order to wipe away unnecessary ink on the nozzle plate, it is preferable to moisten it beforehand. Also, even if the ink adhered to the nozzle plate dries and adheres, it can be easily wiped off if the web 32 is damp. For this reason, the cleaning device 3 sprays the cleaning liquid onto the conveyed web 32 as described above.

The cleaning liquid supply device 5 is installed upstream of the backup roller 31 with respect to the transport path of the web 32 . Since the inkjet head 101 ( FIG. 3 ) contacts the backup roller 31 , the cleaning liquid supply device 5 (especially the spray head 50 ) is installed near the backup roller 31 without interfering with the inkjet head 101 . .

The cleaning liquid supply device 5 sprays the cleaning liquid onto the web 32 . Specifically, the cleaning liquid supply device 5 sprays the cleaning liquid onto the unused portion of the web 32 .

More specifically, the cleaning liquid supply device 5 has the spray head 50 as described above. The spray head 50 is filled with a sheet-like (sheet-like with steps) porous body 52 impregnated with cleaning liquid. Although the details will be described later, the spray head 50 is formed with a plurality of through holes 550 (FIG. 11) for turning the cleaning liquid into mist.

The spray head 50 turns the cleaning liquid impregnated into the porous body 52 into mist by high-frequency vibration, and sprays it onto the unused portion of the web 32 . In this example, the spray head 50 sprays the cleaning liquid onto the area (portion) of the web 32 between the transport roller 34b and the backup roller 31 . The spray head 50 sprays the cleaning liquid to the upstream side of the backup roller 31 in the transport path of the web 32 . The spray head 50 sprays the cleaning liquid toward the surface of the web 32 on the upstream side of the wiping position P.

Specifically, the spray head 50 sprays the cleaning liquid downward from the horizontal. The spray head 50 is driven (operated) by the head drive circuit 7 . By this driving, the spray head 50 sprays the cleaning liquid. The unused portion of the web 32 sprayed with the cleaning liquid is driven by the driving roller 33 to move to the wiping position P where the inkjet head 101 is wiped.

By the way, if the supply (spraying) of the cleaning liquid to the web 32 is stopped at the same time as the wiping operation is stopped, the cleaning liquid between the spray head 50 and the backup roller 31 evaporates by the next operation. Therefore, the amount of cleaning liquid impregnated in the web 32 during this period is reduced. On the other hand, if the supply of the cleaning liquid to the web 32 is stopped before the wiping operation is stopped, there will be a region between the spray head 50 and the backup roller 31 that is not impregnated with the cleaning liquid. Therefore, this area becomes unusable for cleaning.

In this regard, since the spray head 50 uses the sheet-like porous body 52 as described above, the housing itself is thin. Therefore, it is possible to bring the spray head 50 close to the backup roller 31 . Therefore, after wiping the inkjet head 101 once with the web 32 and stopping the operation, when the next wiping operation is started, the web 32 from the spray head 50 to the wiping position P of the backup roller 31 is wasted and the cleaning liquid is used. Waste can be reduced.

The above advantages of the cleaning device 3 will be explained with reference to a comparative example. For example, in another configuration in which the cleaning liquid is dripped from a nozzle (hereinafter also referred to as a "first comparative example"), there is no choice but to wait for the cleaning liquid to spread on the web, which takes a very long time. Therefore, in such a configuration, it is necessary to secure a distance from the cleaning liquid supply position to the backup roller.

Further, in the case of still another configuration (hereinafter also referred to as "second comparative example") in which the cleaning liquid is sprayed from the spray nozzle using high-pressure air (or gas), the distance from the nozzle to the web is set. I have to. Furthermore, since the cleaning liquid spreads less, it is necessary to attach a large number of nozzles.

Therefore, in the configurations of these comparative examples, it is difficult to install the nozzle of the cleaning liquid supply device in the vicinity of the backup roller. On the other hand, in the cleaning device 3 of the present embodiment, the spray head 50 can be installed near the backup roller 31 as described above. Therefore, the cleaning device 3 can reduce the waste described above.

(b2. Configuration example of cleaning liquid supply device)
Next, a specific configuration of the cleaning liquid supply device 5 will be described. FIG. 6 is a perspective view of the cleaning liquid supply device 5. FIG. FIG. 7 is a perspective view of the spray head 50 of the cleaning liquid supply device 5. FIG. FIG. 8 is a bottom view showing the cleaning liquid supply device 5 of FIG. 6 from the direction of arrow VIII.

As shown in FIG. 6 , the cleaning liquid supply device 5 includes a spray head 50 and a tank 54 . The spray head 50 has three vibrators 51 (vibrators 51a, 51b, 51c) and a porous body 52, as described above. Each vibrator 51 is arranged side by side in the transport direction of the paper 900 (Y-axis positive direction). Although details will be described later, each vibrator 51 vibrates at a high frequency.

The tank 54 has a connecting portion 541 , a cleaning liquid supply port 542 and a porous body 55 . The porous body 55 is filled in the tank 54 . The tank 54 stores cleaning liquid and supplies the cleaning liquid to the spray head 50 . The porous body 55 of the tank 54 is impregnated with the cleaning liquid supplied from the cleaning liquid supply port 542 . The porous body 52 of the spray head 50 is also impregnated with the cleaning liquid supplied from the tank 54 .

The spray head 50 and the tank 54 are connected by piercing the connection portion 541 of the tank 54 with the spray head 50 . The spray head 50 is therefore rotatable relative to the tank 54 about the axis 58 .

The XYZ coordinate system in the drawing is a coordinate system based on the printing device 1 and the cleaning device 3 . The xyz coordinate system is a coordinate system (local coordinate system) based on the spray head 50 . Axis Y and axis y are parallel. The XZ plane and the xz plane are parallel. The xy plane is parallel to the bottom surface 57 of the spray head 50 .

As shown in FIG. 7, spray head 50 further includes porous body 53 that supplies cleaning liquid from tank 54 to porous body 52 . The porous body 53 is connected to the porous body 52 . The porous body 53 and the porous body 52 may be integrally formed.

The sheet-like porous body 52 of the spray head 50 has a first portion 521 and a second portion 522 thinner than the first portion 521 . The second portion 522 is in contact with each vibrator 51 .

Thus, by making the second part 522 on the back side of each vibrator 51 into a thin sheet, the thickness of the tip of the spray head 50 is reduced. On the other hand, in the first portion 521 away from the vibrator 51, the porous body 52 is thickened to increase the amount of cleaning liquid to be retained. As a result, during continuous operation, the first portion 521 functions as a buffer, and the cleaning liquid is sufficiently supplied to each vibrator 51 .

As shown in FIG. 8, the porous body 53 is also connected to the porous body 55 of the tank 54 . Thereby, the cleaning liquid in the tank 54 is supplied to the porous body 52 through the porous body 53 . As a result, the cleaning liquid in the tank 54 is supplied to each vibrator 51 .

The liquid level of the cleaning liquid in the tank 54 is set at a position lower than the vibrator 51 (more specifically, a plurality of through holes to be described later). The reason for this is to prevent the cleaning liquid from leaking out when each vibrator 51 is not in operation.

Two wires 59 are connected to each vibrator 51 . Although the details will be described later, each vibrator 51 vibrates by applying electricity to the wiring 59 .

FIG. 9 is a plan view of the vibrator 51 of FIG. 7 viewed in the direction of arrow IX. 10 is a cross-sectional view taken along line XX of FIG. 9. FIG.

As shown in FIGS. 9 and 10, vibrator 51 includes piezoelectric element 511 and diaphragm 512 . Diaphragm 512 includes a central portion 5122 and a peripheral portion 5121 surrounding central portion 5122 .

The piezoelectric element 511 has a hollow cylindrical shape. The piezoelectric element 511 has a hollow circular end face 511a and an end face 511b (FIG. 10) opposite to the end face 511a. The end face 511b is closer to the porous body 52 than the end face 511a.

Diaphragm 512 is a thin disk made of metal. That is, the outer shape of diaphragm 512 is circular. The vibration plate 512 is arranged to cover at least a portion of the end surface 511b of the piezoelectric element 511 . In this example, the diaphragm 512 covers the entire end surface 511b. Specifically, the vibration plate 512 is adhered to the piezoelectric element 511 .

The diaphragm 512 has a first surface 512a and a second surface 512b opposite to the first surface 512a. The first surface 512 a is adhered to the end surface 511 b of the piezoelectric element 511 . The second surface 512b is in contact with the porous body 52 containing the cleaning liquid. Specifically, the second surface 512 b is in contact with the second portion 522 of the porous body 52 .

Specifically, the central portion 5122 of the diaphragm 512 is convex in the positive z-axis direction with respect to the peripheral portion 5121 . A central portion 5122 of the diaphragm 512 is convex. Specifically, the central portion 5122 of the diaphragm 512 is convex in the direction of the inner peripheral surface 511 c of the piezoelectric element 511 .

The material of diaphragm 512 is typically nickel alloy, iron alloy, or aluminum alloy. The thickness of diaphragm 512 is 50 μm or more and 500 μm or less. The outer diameter of the diaphragm 512 is approximately the same as the outer diameter of the piezoelectric element 511 .

Specifically, the piezoelectric element 511 has electrodes (not shown) on each of its top surface and bottom surface. In this example, the end face 511a and the end face 511b are electrode portions. Wiring 59 (see FIG. 8) is connected to these electrodes. By applying a high-frequency voltage between the two electrodes, the piezoelectric element 511 generates vibration that expands and contracts in the z-axis direction (positive and negative directions of the z-axis) and vibration that expands and contracts in the radial direction of the hollow circle.

The piezoelectric element 511 is typically made of ceramic except for the electrodes. The piezoelectric element 511 typically has a thickness (in the z-axis direction) of 1-5 mm and an outer diameter of 10-30 mm. The natural frequency of the piezoelectric element 511 may be 30 kHz to 500 kHz with the diaphragm 512 provided.

FIG. 11 is an enlarged view of a main portion of the diaphragm 512, which is mainly an enlarged main portion. 12 is a cross-sectional view taken along line XII-XII of FIG. 11. FIG.

As shown in FIG. 11, at least the central portion 5122 is formed with a plurality of through holes 550 . The through hole 550 may be formed over the entire central portion 5122, or may be formed only in a portion of the central portion 5122 (typically, in a region near the center of the central portion). good. Also, the through hole 550 may be formed in a part of the peripheral portion 5121 as well.

As shown in FIG. 12, each through-hole 550 has an opening 560 . Specifically, each through hole 550 has an opening 561 and an opening 562 . The opening 561 is an opening on the web 32 side. The opening 562 is an opening on the porous body 52 side.

The through holes 550 are fine holes. The area of openings 561 and 562 of through hole 550 is preferably 1 μm ² or more and 10000 μm ² or less. The diameters of the openings 561 and 562 are preferably 1 μm or more and 100 μm or less. Mist is generated if the diameter of the openings 561 and 562 is 0.1 μm to 100 μm.

Diaphragm 512 is formed with 10,000 through-holes 550 of 10 or more per 1 cm ² . The density of through-holes 550 is preferably 500/cm ² or more and 5000/cm ² or less.

By vibrating the piezoelectric element 511 at a high frequency, the central portion 5122 of the diaphragm 512 vibrates in the positive and negative directions of the z-axis. In this example, the natural frequency of the vibrator 51 is approximately 100 kHz. When the vibrating plate 512 vibrates, the cleaning liquid on the back surface of the vibrating plate 512 (cleaning liquid for the porous body 52) passes through the through-holes 550 and becomes atomized particles (mist) and is dispersed in the air.

Specifically, since the central portion 5122 of the diaphragm 512 is convex, vibration of the diaphragm 512 in the vertical direction (positive and negative directions of the z-axis) is stabilized. This makes it possible to generate a uniform mist. In addition, when the central portion has a planar shape, a distribution of strength of vibration appears, and a portion of strong vibration and a portion of weak vibration appear, so uniform mist is not generated.

(b3. Control of Impregnated Amount of Cleaning Liquid)
If the web 32 is impregnated with too little cleaning liquid, it will be difficult to remove the ink adhered to the nozzle plate of the inkjet head 101 (FIG. 3). Therefore, a certain amount of impregnation is required. Further, since the web 32 has a high ink absorption capacity, if the web 32 impregnates too little cleaning liquid, the web 32 tends to suck ink from the nozzles of the nozzle plate. On the other hand, if the amount of impregnation of the cleaning liquid is too large, the web 32 becomes difficult to absorb the ink adhering to the nozzle plate after purging. Furthermore, if the amount of impregnation is too large, there is a risk that the cleaning liquid will remain on the surface of the nozzle plate.

Regarding this point, the cleaning liquid supply device 5 can freely adjust the impregnation amount of the cleaning liquid based on the type of the web 32 and the state of the nozzle plate of the inkjet head 101 . In other words, the cleaning liquid supply device 5 makes it very easy to adjust the impregnated amount of the cleaning liquid in the web 32 . The reason is explained below.

For example, in another configuration in which the cleaning liquid is dropped from the nozzle described as the first comparative example, the impregnation amount is adjusted by the number of drops per unit time. However, if the impregnation amount is low, intermittent dripping occurs. For this reason, the impregnation amount lacks uniformity. Further, in the configuration in which high-pressure air (or gas) is used to spray the cleaning liquid from the spray nozzle, as described in the second comparative example, if the air (or gas) pressure is set so as to obtain a preferable spray amount, The cleaning liquid does not become a mist. Also, spray nozzles have a slow response to start and stop spraying. Thus, in the second comparative example, it is also difficult to adjust the supply amount of the cleaning liquid.

In response to these, the cleaning liquid supply device 5 according to the present embodiment sprays an atomized cleaning liquid (mist) from a planar vibrator 51 . Therefore, the distance between the oscillator 51 and the web 32 can be shortened. In addition, the responsiveness of mist injection and stopping is higher than that of the configuration of the comparative example described above. Therefore, the cleaning liquid supply device 5 makes it very easy to adjust the spray amount (atomization amount).

Next, a method for adjusting the spray amount of the cleaning liquid will be described. The spray head 50 is driven by the head drive circuit 7 (FIG. 4) as described above. Therefore, the configuration and operation of the head driving circuit 7 will be described.

A vibration plate 512 having a plurality of through holes 550 that are fine holes is vibrated by the piezoelectric element 511 as described above. The vibrator 51 composed of the piezoelectric element 511 and the diaphragm 512 has a natural frequency. When vibration of the same frequency as the natural frequency is applied to the vibrator 51, the vibrator 51 resonates. Energy efficiency is high when the vibrator 51 is vibrated at a frequency (resonance frequency) at which such resonance occurs. Therefore, in the present embodiment, the oscillator 51 is made to resonate.

FIG. 13 is a circuit diagram of the head driving circuit 7 of the cleaning device 3. As shown in FIG. 13 shows a body portion 5111, which is a ceramic portion of the piezoelectric element 511, and electrodes 5112, 5112 of the piezoelectric element 511 for each of the vibrators 51a, 51b, and 51c. not shown.

As shown in FIG. 13, the head driving circuit 7 includes a step-up transformer 71, a switching element 72, a CR circuit 73, a logic element 74, and an oscillation circuit 75. Switching element 72 includes a gate 72g. CR circuit 73 includes a resistance element 73a and a capacitor 73b.

The oscillator circuit 75 is a circuit that outputs a rectangular wave having the same frequency as the natural frequency of the vibrator 51 . The CR circuit 73 cuts the high frequency of the rectangular wave oscillated from the oscillation circuit 75 . The rectangular wave from which the high frequency has been cut is input to the gate 72g of the switching element 72 . The square wave causes the switching element 72 to be repeatedly turned on and off.

The switching element 72 drives the primary side of the step-up transformer 71 . Specifically, when the gate 72g is turned on, a direct current flows from the power supply DC to the coil on the primary side. When the gate 72g is turned off, no DC current flows through the primary coil. By such current control of the primary side coil, the secondary side coil to which the vibrator 51 (51a, 51b, 51c) is connected is supplied with a high-voltage pseudo-sine wave current having the same frequency as the natural frequency. flows. The current flows between the electrodes 5112 and 5112 of the vibrator 51 . As a result, the cleaning liquid is sprayed from the vibrator 51 in an atomized state (mist state).

Specifically, in the head drive circuit 7 , the output from the oscillator circuit 75 is controlled (on/off controlled) using the logic element 74 . In this example, an AND circuit is used as the logic element 74 . A rectangular wave from the oscillation circuit 75 and a control signal from the controller 9 are input to the logic element 74 . The output side of the logic element 74 is connected to the resistance element 73 a of the CR circuit 73 .

The responsiveness of atomization by the vibrator 51 is high. Control using the control signal from the controller 9 and the logic element 74 enables fine control of the spray amount (atomization amount).

14A and 14B are schematic diagrams schematically showing the operation of the head driving circuit 7. FIG.
As shown in FIG. 14, waveform (A) is the output of oscillator circuit 75 . Waveform (B) is the signal input to logic element 74 . Waveform (C) is the output signal output from logic element 74 .

The switching element 72 drives the vibrator 51 with the waveform (C) of the output signal of the logic element 74 . As a result, the atomization is performed only during the time (time t1 to t2 and time t3 to t4) during which the signal of waveform (B) is High. Therefore, the spray amount (atomization amount) can be adjusted by the ratio (duty ratio) between High and Low of the signal of waveform (B).

In this manner, the head driving circuit 7 controls the output of the vibrator 51 with the pulse width. That is, the head drive circuit 7 performs pulse width modulation (PWM) control. The frequency of the signal of waveform (B) is preferably between 0.2 Hz and ten and several Hz.

The driving method described above is merely an example, and in adjusting the spray amount (atomization amount) of the cleaning liquid, the voltage applied to the vibrator 51 may be changed, or the frequency may be adjusted. good.

The head drive circuit 7 may individually control the drive of the piezoelectric element 511 of each vibrator 51 . For example, the oscillation circuit 75 may output a frequency signal individually set for each piezoelectric element 511 . Further, the controller 9 adjusts the High time for each piezoelectric element 511 by sending a control signal (waveform (B) signal) individually set for each logic element 74 to the logic element 74 . good too.

<C. Summary of Cleaning Device>
(1) As shown in FIG. 5, the cleaning device 3 includes a sheet-like web 32 for wiping the inkjet head 101, and a spray head 50 for spraying the web 32 with a mist of cleaning liquid by high-frequency vibration.

Such a configuration eliminates the need for a cleaning liquid pipe and an air pipe (both tubes of 10 Mpa level) for spraying the cleaning liquid using high-pressure air (or gas). Also, a large pump for conveying the cleaning liquid at high pressure is not required. Furthermore, the distance between the spray head 50 and the web 32 can be shorter than in configurations that use high pressure air (or gas) to spray the cleaning liquid. Therefore, the cleaning device 3 can be made smaller than a configuration that sprays the cleaning liquid using high-pressure air (or gas).

(2) As shown in FIG. 11, the spray head 50 is formed with a plurality of through holes 550 for making the cleaning liquid mist. According to such a configuration, the cleaning liquid can be misted by the spray head 50 .

(3) The area of the opening 560 (FIG. 12) of each through-hole 550 is preferably 1 μm ² or more and 10000 μm ² or less. According to such a configuration, the cleaning liquid turns into a mist when passing through each through-hole 550 .

(4) Each opening 560 is preferably circular. The diameter of each opening 560 is preferably 1 μm or more and 100 μm or less. Such a configuration facilitates formation of the through hole 550 .

(5) The spray head 50 preferably has 10 or more and 10,000 through-holes 550 per 1 cm ² . According to such a configuration, a sufficient amount of mist can be sprayed.

(6) As shown in FIG. 5, the spray head 50 sprays the cleaning liquid downward from the horizontal through a plurality of through holes 550 . The spray head 50 is installed near the position where the inkjet head 101 is wiped. With such a configuration, the cleaning device 3 can be miniaturized. Also, the web 32 can be used efficiently.

(7) The spray head 50 includes a vibrator 51 in which a plurality of through holes 550 are formed. With such a configuration, the vibration of the vibrator 51 can spray the cleaning liquid in the form of mist from the through holes 550 .

(8) The vibrator 51 has a vibrating plate 512 in which a plurality of through holes 550 are formed, and a piezoelectric element 511 that vibrates the vibrating plate 512 . The spray head 50 further includes a porous body 52 in contact with the vibration plate 512 and impregnated with the cleaning liquid, as shown in FIGS. As shown in FIGS. 4 and 13, the cleaning device 3 further includes a head drive circuit 7 that drives the piezoelectric element 511 at high frequencies. According to such a configuration, the cleaning liquid contained in the porous body 52 can be sprayed by driving the piezoelectric element 511 .

(9) The piezoelectric element 511 has a hollow cylindrical shape. As shown in FIG. 10, the piezoelectric element 511 has a hollow circular end face 511a and an end face 511b opposite to the end face 511a. The end face 511b is closer to the porous body 52 than the end face 511a. Diaphragm 512 has a circular outer shape. The vibration plate 512 is arranged to cover at least a portion of the end surface 511b of the piezoelectric element 511 . With such a configuration, the driving force of the piezoelectric element 511 can be efficiently transmitted to the diaphragm 512 .

(10) As shown in FIG. 10, the central portion 5122 of the diaphragm 512 is convex toward the inner peripheral surface of the piezoelectric element 511 . As shown in FIG. 11 , at least some of the plurality of through holes 550 are formed in the central portion 5122 . With such a configuration, the vibration of diaphragm 512 is stabilized. This makes it possible to generate a uniform mist.

(11) As shown in FIGS. 4, 6 to 8, and 13, the spray head 50 has a plurality of vibrators 51 (51a, 51b, 51c). As shown in FIG. 13, the head driving circuit 7 individually controls driving of the piezoelectric elements 511 of the vibrators 51 . According to such a configuration, it becomes possible to perform spray control with higher accuracy.

(12) As shown in FIG. 3, the cleaning device 3 is built in the printing device 1 . In the printing apparatus 1, a plurality of inkjet heads 101 (FIG. 3) are arranged in the conveying direction (arrow 993 direction in FIG. 2) of the printing paper 900 (FIG. 2). Each transducer 51 is arranged side by side in the transport direction. According to such a configuration, mist of the cleaning liquid can be individually sprayed onto each area of the web 32 for wiping each inkjet head 101 .

(13) As shown in FIG. 7, the porous body 52 has a first portion 521 and a second portion 522 which is thinner than the first portion 521 in the penetration direction of the through hole 550 (see FIG. 12). . As shown in FIGS. 7 and 10, the second portion 522 contacts the diaphragm 512 . With such a configuration, the cleaning liquid can be stored in the first portion 521 . That is, the first portion 521 can function as a buffer portion for the second portion 522 . Also, since the second portion 522 is thinner than the first portion 521, the tip portion of the spray head 50 can be made thinner.

(14) As shown in FIGS. 6 and 8, the cleaning device 3 further includes a tank 54 that stores cleaning liquid and supplies the cleaning liquid to the spray head 50 . The level of the cleaning liquid in the tank 54 is lower than the positions of the plurality of through holes 550 . Such a configuration can prevent the cleaning liquid from leaking from the plurality of through holes 550 .

(15) The head drive circuit 7 drives the piezoelectric element 511 by any of voltage control, frequency control, and pulse width modulation control. With such a configuration, the spray amount of the cleaning liquid can be adjusted.

(16) The spray head 50 mists the cleaning liquid and sprays it onto the unused portion of the web 32 . The cleaning device 3 moves the unused portion sprayed with the cleaning liquid to the wiping position P (FIG. 5) where the inkjet head 101 is wiped.

(17) According to the cleaning device 3, it is possible to spread the cleaning liquid evenly over the web 32. FIG. In particular, the cleaning device 3 can spread the cleaning liquid across the width of the web 32 to the ends. According to the cleaning device 3, the degree of freedom of selection of the web 32 is increased.

<D. Variation>
A configuration for controlling the impregnated amount of the cleaning liquid in the web 32 to a specified (set) impregnated amount will be described.

FIG. 15 is a schematic diagram for explaining the hardware configuration of a modification of the cleaning device 3. As shown in FIG.

As shown in FIG. 15, the cleaning device 3A differs from the cleaning device 3 in that it has a platen 6 that functions as a sensor. The platen 6 is installed upstream of the backup roller 31 and downstream of the spray head 50 .

FIG. 16 is a diagram for explaining the platen 6. FIG. As shown in FIG. 16, the platen 6 has three electrode pairs 61 . Each electrode pair 61 has an electrode 61a and an electrode 61b spaced from electrode 61a by a predetermined distance.

Three electrode pairs 61 are arranged to contact the surface of web 32 . Each electrode pair 61 is arranged at a position corresponding to each different vibrator 51 .

Since the web 32 is under constant tension, the web 32 is pressed against the platen 6 with constant pressure. By applying a voltage to the three electrode pairs 61 , a current corresponding to the impregnated amount of the cleaning liquid in the web 32 flows through each electrode pair 61 . The cleaning device 3A controls the output of each vibrator 51 by detecting the current. Thereby, the amount of the cleaning liquid impregnated into the web 32 can be arbitrarily adjusted.

FIG. 17 is a diagram for explaining the head driving circuit of the cleaning device 3A.
As shown in FIG. 17, the head drive circuit 7A includes a step-up transformer 71, a switching element 72, a CR circuit 73, a logic element 74, a peripheral controller 76, an operational amplifier 77, a detection resistor 78, and an analog switch 79. and The peripheral controller 76 has two setting switches 761 and 762 . Note that the head drive circuit 7A does not include the oscillation circuit 75. FIG.

The peripheral controller 76 itself generates signals for driving the three vibrators 51 by executing a software program. Specifically, the peripheral controller 76 outputs the same signal as the waveform (C) shown in FIG. Generate. At that time, the peripheral controller 76 determines the on/off ratio (duty ratio) that determines the spray amount (atomization amount) based on the current flowing through the electrode pair 61 of the platen 6 .

Next, current detection will be described below. The analog switch 79 is turned on and off according to commands from the peripheral controller 76 . By turning on the analog switch 79, a voltage is applied between the electrodes 61a and 61b.

If a voltage is constantly applied between the electrodes 61a and 61b, the current flowing through the cleaning liquid will change (decrease). Therefore, highly accurate detection cannot be performed. By using the analog switch 79 as described above, it is possible to apply voltage only when necessary. Therefore, the configuration provided with the analog switch 79 enables more accurate detection than the configuration in which the voltage is constantly applied between the electrodes 61a and 61b.

Specifically, when a voltage is applied between the electrodes 61a and 61b, a current corresponding to the amount of cleaning liquid in the web 32 flows between the electrodes 61a and 61b. The peripheral controller 76 detects the amount of cleaning liquid with which the web 32 is impregnated based on the current flowing between the electrodes 61a and 61b. Specifically, the current flowing between the electrodes 61a and 61b is detected as a voltage signal by a detection resistor 78 and an operational amplifier 77 with a high input resistance. The detected voltage signal is input from the operational amplifier 77 to the peripheral controller 76 .

The peripheral controller 76 determines the on/off ratio of the vibrator 51 based on the detected impregnation amount of the cleaning liquid (more specifically, the detected voltage signal). The determination processing of the ratio is performed using software (program) in the peripheral controller 76 .

A more detailed description is as follows. The peripheral controller 76 has two setting switches 761 and 762 as described above. Setting switches 761 and 762 are for setting the spray amount of each of the three vibrators 51 .

FIG. 18 is a diagram showing the relationship between the setting switches 761 and 762 and the output of the vibrator 51. As shown in FIG.

As shown in FIG. 18, two setting switches 761 and 762 can set four output patterns with a 2-bit signal. When both of the setting switches 761 and 762 are on, pattern #0 is obtained and the outputs of the three vibrators 51 are low. As a result, the spray amount of the three vibrators 51 is reduced. When the setting switch 761 is on and the setting switch 762 is off, pattern #1 is obtained, and the outputs of the three vibrators 51 are high. As a result, the spray amount of the three vibrators 51 increases.

When the setting switch 761 is off and the setting switch 762 is on, pattern #2 is obtained, and only the output of the vibrator 51c becomes high. The outputs of the remaining two transducers 51a and 51b go low. When both of the setting switches 761 and 762 are on, pattern #3 results, and only the output of the vibrator 51a becomes high. The outputs of the remaining two transducers 51b and 51c go low. In patterns #2 and #3, the amount of mist sprayed from the vibrator 51 at the end of the three vibrators is large.

When the output of the vibrator 51 is low, the spray amount is 2g/m ² to 3g/m ² . In this case, the web 32 is still in a state of being able to absorb ink sufficiently. When the output of the vibrator 51 is high, the spray amount is 8g/m ² to 9g/m ² . In this case, the web 32 is sufficiently impregnated with the cleaning liquid.

The setting switches 761 and 762 can be directly operated by the user. The setting switches 761 and 762 are also operated by a signal from an unillustrated host sequencer that controls the printing apparatus 1 . The setting switches 761 and 762 can be arbitrarily switched by the controller 9 including the upper sequencer after purging and after finishing the print job.

An operation start signal from the controller 9 is also input to the peripheral controller 76 . That is, a series of wiping operations are started by a command from the controller 9 .

FIG. 19 is a flowchart for explaining the control structure of the cleaning device 3A. Note that the sequence shown in FIG. 19 is executed for each transducer 51 .

As shown in FIG. 19, in step S1, the peripheral controller 76 receives an input of an operation start signal from the higher controller 9. As shown in FIG. In step S2, the peripheral controller 76 confirms the ON/OFF states of the setting switches 761 and 762. FIG.

In step S3, the peripheral controller 76 drives the vibrator 51 with default settings. In step S<b>4 , the roller drive device 37 ( FIG. 4 ) drives the drive roller 33 . In step S5, the peripheral controller 76 checks the voltage between the electrodes 61a and 61b.

In step S6, the peripheral controller 76 controls driving of the vibrator 51 based on the voltage between the electrodes 61a and 61b. In step S7, the peripheral controller 76 determines whether or not the web 32 has been conveyed by the roller driving device 37 by a predetermined length.

If it is determined that the web 32 has been conveyed by the predetermined length (YES in step S7), the peripheral controller 76 stops driving the oscillator 51 in step S8. If it is determined that the web 32 has not been conveyed by the predetermined length (NO in step S7), the peripheral controller 76 returns the process to step S5. After step S8, the roller driving device 37 stops driving the driving roller 33 in step S9.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

REFERENCE SIGNS LIST 1 printing device 2 paper conveying device 3, 3A cleaning device 4 head standby unit 5 cleaning liquid supply device 6 platen 7, 7A head driving circuit 9 controller 10 head station 11 head moving device 20 transport belt, 21, 33 drive roller, 22 driven roller, 30 web transport device, 31 backup roller, 32 web, 34a, 34b transport roller, 35 web supply roller, 36 web winding roller, 37 roller drive device, 38a, 38b motor, 39a, 39b motor drive circuit, 41 cap, 42 waste liquid tank, 50 spray head, 51, 51a, 51b, 51c vibrator, 52, 53, 55 porous body, 54 tank, 57 bottom surface, 58, Y, y axes, 59 wiring, 61 electrode pair, 61a, 61b, 5112 electrode, 71 step-up transformer, 72 switching element, 72g gate, 73 circuit, 73a resistance element, 73b capacitor, 74 logic element, 75 oscillation circuit, 76 peripheral controller, 77 operational amplifier, 78 detection resistor 79 analog switch 101 inkjet head 560,561,562 opening 550 through hole 511 piezoelectric element 511a, 511b end surface 511c inner peripheral surface 512 vibration plate 512a first surface 512b second second surface Surface 521 first portion 522 second portion 541 connection portion 542 cleaning liquid supply port 761, 762 setting switch 900 paper 5111 main body portion 5121 peripheral portion 5122 central portion P wiping position.

Claims (18)

a sheet-like web for wiping the inkjet head;
A cleaning device, comprising: a spray head for spraying a mist of cleaning liquid onto the web by high-frequency vibration. 2. The cleaning device according to claim 1, wherein said spray head is formed with a plurality of through-holes for forming a mist of said cleaning liquid. 3. The cleaning device according to claim 2, wherein the opening of each through-hole has an area of 1 μm ² or more and 10000 μm ² or less. each said opening is circular;
4. The cleaning device of claim 3, wherein the diameter of each said opening is greater than or equal to 1 [mu]m and less than or equal to 100 [mu]m. The cleaning device according to any one of claims ² to 4, wherein the spray head has 10 or more and 10,000 through-holes per 1 cm2. The spray head is
spraying the cleaning liquid downward from the horizontal through the plurality of through-holes;
The cleaning device according to any one of claims 2 to 5, which is installed near a position for wiping the inkjet head. 7. The cleaning device according to any one of claims 2 to 6, wherein said spray head includes a vibrator in which said plurality of through holes are formed. The vibrator has a diaphragm in which the plurality of through holes are formed, and a piezoelectric element that vibrates the diaphragm,
the spray head further includes a porous body in contact with the diaphragm and impregnated with the cleaning liquid;
8. The cleaning device according to claim 7, further comprising a drive circuit for driving said piezoelectric element at high frequencies. The piezoelectric element has a hollow columnar shape and has a first end face of the hollow circle and a second end face opposite to the first end face,
the second end face is closer to the porous body than the first end face,
9. The cleaning device according to claim 8, wherein said vibration plate has a circular outer shape and is arranged to cover at least a portion of said second end face of said piezoelectric element. the central portion of the diaphragm is convex in the direction of the inner peripheral surface of the piezoelectric element;
10. The cleaning device according to claim 9, wherein at least some of said plurality of through holes are formed in said central portion. The spray head has a plurality of vibrators,
11. The cleaning device according to any one of claims 8 to 10, wherein said drive circuit individually controls driving of said piezoelectric elements of said vibrators. The cleaning device is incorporated in a printing device, and in the printing device, a plurality of the inkjet heads are arranged in a conveying direction of printing paper,
12. The cleaning device according to claim 11, wherein said vibrators are arranged side by side in said transport direction. The porous body has a first portion and a second portion in which the thickness of the through-hole in the through-hole direction is thinner than that of the first portion,
13. The cleaning device according to any one of claims 8 to 12, wherein said second portion is in contact with said diaphragm. further comprising a tank that stores the cleaning liquid and supplies the cleaning liquid to the spray head;
14. The cleaning device according to claim 13, wherein the level of the cleaning liquid in the tank is lower than the positions of the plurality of through holes. 15. The cleaning device according to any one of claims 8 to 14, wherein said drive circuit drives said piezoelectric element by any one of voltage control, frequency control, and pulse width modulation control. The cleaning device
further comprising an electrode pair that contacts the web impregnated with the cleaning liquid;
detecting the amount of the cleaning liquid impregnated in the web based on the current flowing between the electrode pair;
16. The cleaning device according to claim 15, wherein said drive circuit drives said piezoelectric element based on the result of said detection so that the amount of said cleaning liquid impregnating said web approaches a predetermined amount. The spray head sprays the cleaning liquid in the form of a mist onto an unused portion of the web,
17. The cleaning device according to any one of claims 1 to 16, wherein the cleaning device moves the unused portion sprayed with the cleaning liquid to a position for wiping the inkjet head. inkjet head,
and a cleaning device for cleaning the inkjet head,
The cleaning device
a sheet-like web for wiping the inkjet head;
and a spray head for spraying a cleaning liquid in the form of mist onto the web by high-frequency vibration.

Images