Cleaning device and cleaning method for liquid spray heads

Abstract

This technology provides a way to remove foreign matter from a nozzle plate. [Solution] In a cleaning device for a liquid spray head, the liquid spray head has a nozzle plate on which a plurality of nozzles for spraying liquid are formed, a pressure chamber communicating with the nozzles, a diaphragm defining a part of the pressure chamber, and a piezoelectric element laminated on the diaphragm. The cleaning device includes an ultrasonic device having an ultrasonic element that transmits ultrasonic waves toward the nozzle plate, a wiper that wipes the spray surface of the nozzle plate, and a detection unit that detects nozzles to which foreign matter is attached. The ultrasonic device drives the ultrasonic element so that ultrasonic waves are transmitted to a target region which is the area including the nozzle opening of the target nozzle to which foreign matter is attached as detected by the detection unit, and the wiper wipes over the nozzle opening of the target nozzle after the ultrasonic waves are transmitted.

Description

Technical Field

[0001] The present disclosure relates to the technology of a liquid ejecting head cleaning apparatus and a cleaning method.

Background Art

[0002] Conventionally, a technique for removing residual substances remaining in an inkjet head having nozzles is known (Patent Document 1). In this technique, cavitation is generated by ultrasonically vibrating the cleaning liquid while the inkjet head is immersed in the cleaning liquid, and bubbles generated by cavitation are collided with the residual substances to peel the residual substances from the inner wall of the nozzle of the inkjet head. Thereafter, a wiper is moved while being in contact with the ejection surface of the inkjet head on which nozzle openings are formed, and the residual substances are wiped off from the ejection surface, thereby removing the residual substances remaining in the inkjet head.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] In the conventional technique, ultrasonic waves are uniformly transmitted toward the entire ejection surface without detecting which nozzle of a liquid ejecting head such as an inkjet head foreign matters such as residual substances adhere to, so bubbles generated by cavitation are dispersed throughout the cleaning liquid. Therefore, the bubbles generated by cavitation do not collide with the nozzle to which the foreign matters adhere, and thus the foreign matters may not be sufficiently peeled off or lifted from the ejection surface or the inner wall of the nozzle in some cases.

Means for Solving the Problem

[0005] (1) According to one embodiment of the present disclosure, a cleaning device for a liquid spray head is provided. In the cleaning device for a liquid spray head, the liquid spray head has a nozzle plate on which a plurality of nozzles for spraying liquid are formed, a pressure chamber communicating with the nozzles, a diaphragm defining a part of the pressure chamber, and a piezoelectric element laminated on the diaphragm, the cleaning device comprises an ultrasonic device having an ultrasonic element that transmits ultrasonic waves toward the nozzle plate, a wiper that wipes the spray surface of the nozzle plate, and a detection unit that detects the nozzles to which foreign matter is attached, the ultrasonic device drives the ultrasonic element so that ultrasonic waves are transmitted to a target region which is a region including the nozzle opening of the target nozzle that is the nozzle to which the foreign matter detected by the detection unit is attached, and the wiper wipes over the nozzle opening of the target nozzle after the transmission of the ultrasonic waves. (2) Another embodiment of the present disclosure provides a method for cleaning a liquid spray head. The method for cleaning a liquid spray head having a nozzle plate on which a plurality of nozzles for spraying liquid are formed comprises: a detection step of detecting a nozzle to which foreign matter is attached; a first cleaning step of driving an ultrasonic element to transmit ultrasonic waves to a target region which is a region including the nozzle opening of the target nozzle to which the foreign matter detected in the detection step is attached; and a second cleaning step of driving a wiper after the transmission of ultrasonic waves to wipe the nozzle opening of the target nozzle with the wiper. [Brief explanation of the drawing]

[0006] [Figure 1] A diagram showing the configuration of a liquid injection system. [Figure 2] Figure 1 illustrates the cleaning method in the first embodiment. [Figure 3] Figure 2 illustrates the cleaning method in the first embodiment. [Figure 4] Figure 3 illustrates the cleaning method in the first embodiment. [Figure 5] A flowchart illustrating the cleaning method in the first embodiment. [Figure 6]A diagram illustrating the cleaning method in the second embodiment. [Figure 7] A diagram illustrating an example of a cleaning method in the third embodiment. [Figure 8] A diagram illustrating another example of the cleaning method in the third embodiment. [Figure 9] A diagram illustrating yet another example of the cleaning method in the third embodiment. [Figure 10] A diagram illustrating yet another example of the cleaning method in the third embodiment. [Figure 11] A diagram illustrating the cleaning method in the fourth embodiment. [Modes for carrying out the invention]

[0007] A. First Embodiment: Figure 1 shows the configuration of the liquid injection system 1. Figure 1 depicts three mutually orthogonal spatial axes, the X, Y, and Z axes. The arrows on the X, Y, and Z axes point in the positive directions along the X, Y, and Z axes, respectively. These positive directions along the X, Y, and Z axes are designated as the +X, +Y, and +Z directions, respectively. The directions opposite to those pointed to by the X, Y, and Z axes represent the negative directions along the X, Y, and Z axes, respectively. These negative directions along the X, Y, and Z axes are designated as the -X, -Y, and -Z directions, respectively. The directions along the X, Y, and Z axes, regardless of whether they are positive or negative, are designated as the X, Y, and Z directions, respectively.

[0008] In this embodiment, when the liquid injection system 1 is in use, the X and Y axes are axes aligned with the horizontal plane, and the Z axis is an axis aligned with the direction of gravity. Hereafter, the direction of gravity will be referred to as the -Z direction, and the direction of anti-gravity will be referred to as the +Z direction. The direction from the rear side to the front side of the liquid injection system 1 will be referred to as the -X direction, and the direction from the front side to the rear side will be referred to as the +X direction. Also, when the liquid injection system 1 is viewed from the front side, the direction from right to left will be referred to as the -Y direction, and the direction from left to right will be referred to as the +Y direction. Note that "liquid injection system 1 in use" refers to the state in which the liquid injection system 1 is installed on a horizontal surface. The same applies to the figures and descriptions shown hereafter.

[0009] The liquid injection system 1 comprises a liquid injection device 10 and a cleaning device 50.

[0010] In this embodiment, the liquid ejection device 10 is an inkjet printer that ejects ink as a liquid from a liquid ejection head 14. The liquid ejection device 10 comprises a cartridge mounting section 11, a liquid flow pipe 12, a carriage 13, a liquid ejection head 14, a control device 15, a drive mechanism 16, and a transport mechanism 17.

[0011] One or more cartridges 20 are detachably mounted in the cartridge mounting section 11. In this embodiment, four types of cartridges 20 are mounted in the cartridge mounting section 11, corresponding to four ink colors: yellow (Y), magenta (M), cyan (C), and black (K). However, the types and number of cartridges 20 mounted in the cartridge mounting section 11 are not limited to these. A liquid flow pipe 12 for circulating ink is connected to the cartridge mounting section 11.

[0012] A liquid spray head 14 is provided on the carriage 13. The carriage 13 moves the liquid spray head 14 relative to the object TG to be sprayed, such as printing paper.

[0013] A liquid flow pipe 12 is connected to the liquid ejecting head 14. Ink is supplied to the liquid ejecting head 14 from a cartridge 20 mounted in a cartridge mounting portion 11 via the liquid flow pipe 12. The liquid ejecting head 14 is provided with a plurality of nozzles 141 for ejecting ink as liquid for each type of ink. The liquid ejecting head 14 ejects ink from the nozzles 141 toward an ejection target TG such as printing paper. Thereby, the liquid ejecting head 14 prints data such as characters and images. In the present embodiment, the liquid ejecting apparatus 10 is a so-called "off-carriage type" printer in which the cartridge mounting portion 11 is not interlocked with the movement of the carriage 13. In contrast, the technology of the present disclosure can also be applied to a so-called "on-carriage type" printer in which the cartridge mounting portion 11 is provided on the carriage 13 and the cartridge mounting portion 11 moves together with the carriage 13.

[0014] The control device 15 controls each part of the liquid ejecting system 1. In the present embodiment, the control device 15 functions as an ejection control unit 151 and a cleaning control unit 155. The ejection control unit 151 controls each part of the liquid ejecting apparatus 10 and transmits and receives signals to and from the cartridge 20. The cleaning control unit 155 controls driving of an ultrasonic device 53 and a wiper 54, which will be described later, of the cleaning device 50.

[0015] The drive mechanism 16 reciprocates the carriage 13 based on a control signal received from the ejection control unit 151. The drive mechanism 16 includes a timing belt 161 and a drive motor 162. The drive mechanism 16 transmits the power of the drive motor 162 to the carriage 13 via the timing belt 161, thereby reciprocating the carriage 13 in the main scanning direction. In the present embodiment, the main scanning direction is a direction along the Y direction. The conveyance mechanism 17 moves the ejection target TG in a sub-scanning direction intersecting the main scanning direction based on a control signal received from the ejection control unit 151. In the present embodiment, the sub-scanning direction is a direction along the X direction.

[0016] FIG. 2 is a first diagram for explaining the cleaning method of the liquid ejecting head 14 according to the first embodiment. FIG. 3 is a second diagram for explaining the cleaning method of the liquid ejecting head 14 according to the first embodiment. FIG. 4 is a third diagram for explaining the cleaning method of the liquid ejecting head 14 according to the first embodiment.

[0017] As shown in FIGS. 2 and 3, the liquid ejecting head 14 includes a nozzle plate 142 having a plurality of nozzles 141 formed therein, pressure chambers 143 communicating with the respective nozzles 141, a vibration plate 144 that defines a part of the pressure chambers 143, and piezoelectric elements 145 stacked on the vibration plate 144. Furthermore, the liquid ejecting head 14 is connected to the liquid flow pipe 12, and includes a common liquid chamber (not shown) provided commonly for the plurality of nozzles 141, and individual flow paths 146 connecting the common liquid chamber and the pressure chambers 143. The ink IN supplied to the liquid ejecting head 14 via the liquid flow pipe 12 is temporarily stored in the common liquid chamber, and then supplied to the pressure chambers 143 via the individual flow paths 146. When the piezoelectric elements 145 vibrate based on a control signal received from the ejection control unit 151, the vibration is transmitted to the vibration plate 144, the pressure in the pressure chambers 143 fluctuates, and the volume of the pressure chambers 143 changes. Thereby, the ink IN contained in the pressure chambers 143 is ejected from the nozzles 141.

[0018] The cleaning device 50 cleans the periphery of the nozzles 141 and removes foreign matters FO from the liquid ejecting head 14. The "foreign matter FO" mentioned herein refers to an object adhering to the ejection surface 142a of the nozzle plate 142 or the inner wall 141b of the nozzle shown in FIG. 2, for example, solidified ink IN or a fibrous object other than ink IN. The "ejection surface 142a of the nozzle plate 142" refers to the surface of the nozzle plate 142 on which the nozzle openings 141a are formed. The "nozzle opening 141a" refers to a portion of the nozzle 141 that opens toward the outside. The cleaning device 50 includes a detection unit 51, a cap 52, an ultrasonic device 53, and a wiper 54.

[0019] The detection unit 51 detects nozzles 141 to which foreign matter FO is attached. The detection unit 51 detects nozzles 141 to which foreign matter FO is attached by, for example, using residual vibration when the piezoelectric element 145 is vibrated to determine whether or not foreign matter FO is attached to each nozzle 141. The detection unit 51 may also detect nozzles 141 to which foreign matter FO is attached by recognizing the pattern formed on the target object TG when ink IN is ejected from all nozzles 141 and determining whether or not foreign matter FO is attached to each nozzle 141. In other words, the detection unit 51 may print a nozzle check pattern and detect nozzles 141 to which foreign matter FO is attached by determining whether or not foreign matter FO is attached to each nozzle 141 according to the dot defects in the printed nozzle check pattern. Alternatively, the detection unit 51 may detect nozzles 141 to which foreign matter FO is attached by analyzing an image of the ejection surface 142a of the nozzle plate 142 and determining whether or not foreign matter FO is attached to each nozzle 141.

[0020] The cap 52 is capable of containing liquid LQ. Here, "liquid LQ" may be the liquid sprayed from the liquid spray head 14, i.e., ink IN, or it may be another liquid other than the liquid sprayed from the liquid spray head 14, such as a cleaning agent. The cap 52 is positioned opposite the spray surface 142a of the nozzle plate 142 when cleaning the liquid spray head 14, and is capable of covering the spray surface 142a of the nozzle plate 142. In this embodiment, the cap 52 is provided at the home position HP. Here, "home position HP" is located in the area of ​​the liquid spray device 10 where no spray target object TG is placed, i.e., the non-printing area, as shown in Figure 1. Furthermore, in this embodiment, in order to prevent color mixing during cleaning and to selectively clean the nozzles 141 that do not require cleaning without cleaning the nozzles 141 that do not require cleaning, the cap 52 is provided for each nozzle row NR, as shown in Figure 3. Here, "nozzle row NR" refers to a row formed by arranging multiple nozzles 141 that spray ink IN of the same color in a row on the nozzle plate 142. In this embodiment, the direction in which the nozzle row NR is formed is along the Y direction. In the following, when it is necessary to distinguish between multiple nozzles 141 within the nozzle row NR, each nozzle 141 is distinguished using the "nozzle number N" which is sequentially assigned to each nozzle 141 from one end of the nozzle row NR to the other. Note that caps 52 may be provided for each ink color.

[0021] As shown in Figure 2, the ultrasonic device 53 uses ultrasonic vibrations to detach or lift foreign matter FO from the nozzle inner wall 141b or the spray surface 142a of the nozzle plate 142. The ultrasonic device 53 has one or more ultrasonic elements 530 that transmit ultrasonic waves US toward the nozzle plate 142. The ultrasonic device 53 drives the ultrasonic elements 530 so that ultrasonic waves US are transmitted to the target region AR, which is the region including the nozzle opening 141a of the target nozzle 141t detected by the detection unit 51 as a nozzle 141 to which foreign matter FO is attached. In this embodiment, as shown in Figure 3, the ultrasonic device 53 having one ultrasonic element 530 is fixed to the cap 52 so as to be movable along the nozzle row NR. As shown in Figure 2, the ultrasonic device 53 transmits ultrasonic waves US to the liquid LQ contained in the cap 52 while the spray surface 142a of the nozzle plate 142 is covered by the cap 52, causing the liquid LQ in the cap 52 to vibrate. This allows the ultrasonic device 53 to transmit ultrasonic waves US toward the nozzle plate 142. Based on the control signal received from the cleaning control unit 155, the ultrasonic device 53 moves in the direction DM along the nozzle row NR inside the cap 52, and drives the ultrasonic element 530 when it reaches a position where it can transmit ultrasonic waves US to the target area AR. As a result, the ultrasonic device 53 transmits ultrasonic waves US to the target area AR.

[0022] After the transmission of ultrasonic waves, the wiper 54 wipes the nozzle opening 141a of the target nozzle 141t, thereby wiping away foreign matter FO from the spray surface 142a of the nozzle plate 142. Here, "wiping" refers to the operation of moving the wiper 54 while keeping it in contact with the spray surface 142a of the nozzle plate 142. In this embodiment, as shown in Figure 3, one wiper 54 is fixed to the cap 52 so as to be movable along the nozzle row NR, and moves in accordance with the ultrasonic device 53. As a result, as shown in Figure 2, after the transmission of ultrasonic waves, the wiper 54 wipes the nozzle opening 141a of the target nozzle 141t.

[0023] Figure 5 is a flowchart showing the cleaning method for the liquid spray head 14 in the first embodiment. The flow shown in Figure 5 is performed for each nozzle row NR.

[0024] If step S101 is "No", that is, if the nozzle row NR to be detected does not require cleaning, this flow ends. "Cleaning is required" here means, for example, when the detection unit 51 detects a predetermined number or more target nozzles 141t from the nozzle row NR to be detected. "Cleaning is required" may also mean that a predetermined amount of time has elapsed since the previous cleaning operation, or a cleaning operation request has been received from the user. If step S101 is "Yes", that is, if the nozzle row NR to be detected requires cleaning, step S102 is executed.

[0025] In step S102, as shown in Figure 3, the liquid spray head 14 moves onto the cap 52 located at the home position HP. Then, the nozzle opening 141a of the nozzle row NR to be cleaned is capped. Here, "capping" refers to the action of covering at least a portion of the spray surface 142a of the nozzle plate 142 with the cap 52, thereby forming a closed space capable of containing the liquid LQ.

[0026] As shown in Figure 5, step S103 is performed after step S102. In step S103, ink IN as liquid LQ is filled into the cap 52, and the inside of the cap 52 is filled with ink IN. The filling of ink IN may be performed by sucking ink IN with a pump (not shown) connected to the cap 52, or by spraying ink IN from the nozzle 141. As a result, as shown in the left diagram of Figure 2, the spray surface 142a of the nozzle plate 142 comes into contact with ink IN.

[0027] As shown in Figure 5, after step S103, each step from step S104 onwards is executed. Each step from step S104 onwards is executed sequentially from one end of the nozzle row NR to the other. In other words, each step from step S104 onwards is executed repeatedly, starting from the first nozzle 141, whose nozzle number N is "1" as shown in Figure 3, until the nozzle with the highest nozzle number, 141, whose nozzle number N is "L".

[0028] As shown in Figure 5, if step S104 is "Yes", that is, if foreign matter FO is attached to the Mth nozzle 141 (where M is an integer between 1 and L), then step S105 is executed. In other words, if the Mth nozzle 141 is the target nozzle 141t detected by the detection unit 51, then step S105 is executed. In step S105, the cleaning control unit 155 moves the ultrasonic device 53 in a predetermined direction DM. Then, when the ultrasonic device 53 reaches a position where it can transmit ultrasonic waves US to the target region AR including the nozzle opening 141a of the Mth nozzle 141, the cleaning control unit 155 drives the ultrasonic element 530. As a result, as shown in the center diagram of Figure 2, the ultrasonic device 53 transmits ultrasonic waves US to the target region AR including the nozzle opening 141a of the Mth nozzle 141. As shown in Figure 5, if step S104 is "No", that is, if foreign matter FO is not attached to the Mth nozzle 141, then step S105 is not executed and step S108 is executed. In other words, if the M-th nozzle 141 is not the target nozzle 141t detected by the detection unit 51, the ultrasonic device 53 does not transmit ultrasonic waves US to the target region AR including the nozzle opening 141a of the M-th nozzle 141, and the process proceeds to step S108.

[0029] If step S106 is "No", that is, if the nozzle number N of the Mth nozzle 141 is not "1", then step S107 is executed. In step S107, the cleaning control unit 155 moves the wiper 54 in a predetermined direction DM. As a result, the wiper 54 wipes over the nozzle opening 141a of the M-1th nozzle 141, as shown in the right diagram of Figure 2. In other words, as shown in Figure 4, after ultrasonic waves US are transmitted to the target area AR and foreign matter FO is detached or lifted from the nozzle inner wall 141b or the spray surface 142a of the nozzle plate 142, the wiper 54 wipes over the nozzle opening 141a of the target nozzle 141t. If step S106 is "Yes", that is, if the nozzle number N of the Mth nozzle 141 is "1", then the M-1th nozzle 141 is not present on the nozzle plate 142, so step S107 is not executed and the process proceeds to step S108.

[0030] If step S108 is "No", that is, if the nozzle number N of the M-th nozzle 141 is not "L", which is the maximum nozzle number, then each step from step S104 onwards is executed for the next M+1-th nozzle 141 adjacent to the M-th nozzle 141. If step S108 is "Yes", that is, if the nozzle number N of the M-th nozzle 141 is "L", which is the maximum nozzle number, then this flow terminates.

[0031] The configuration of the ultrasonic device 53 and the wiper 54 is not limited to the above. The ultrasonic device 53 and the wiper 54 may be configured to move along the X direction perpendicular to the direction in which the nozzle row NR is formed, for example.

[0032] According to the first embodiment described above, the cleaning device 50 transmits ultrasonic waves US towards the nozzle plate 142, thereby detaching or lifting foreign matter FO from the nozzle plate 142 by cavitation-induced destruction or by the added mass force due to sound pressure. At this time, the cleaning device 50 can detect which nozzle 141 has foreign matter FO attached to it and transmit ultrasonic waves US to the target region AR including the nozzle opening 141a of the target nozzle 141t that has foreign matter FO attached. In other words, the cleaning device 50 can transmit ultrasonic waves US locally towards the target region AR without uniformly transmitting ultrasonic waves US to the entire spray surface 142a of the nozzle plate 142. With this configuration, bubbles due to cavitation can be concentrated and generated in the target region AR. Therefore, the possibility of bubbles generated by cavitation colliding with foreign matter FO can be increased. Thus, foreign matter FO can be sufficiently detached or lifted from the spray surface 142a and the inner wall 141b of the nozzle plate 142.

[0033] Furthermore, according to the first embodiment described above, the cleaning device 50 can transmit ultrasonic waves (US) locally toward the target area AR. In this configuration, since ultrasonic waves (US) are transmitted only to the target area AR, energy efficiency can be improved.

[0034] Furthermore, according to the first embodiment described above, the cleaning device 50 can locally transmit ultrasonic waves (US) toward the target area AR. In this configuration, ultrasonic waves (US) are not transmitted toward the nozzle plate 142 more than necessary, thus reducing the possibility of damage to the nozzle plate 142.

[0035] Furthermore, according to the first embodiment described above, the cleaning device 50 can wipe the nozzle opening 141a of the target nozzle 141t after transmitting ultrasonic waves US towards the nozzle plate 142. In other words, according to the first embodiment described above, the liquid spray head 14 can be cleaned by performing a detection step, a first cleaning step, and a second cleaning step. The "detection step" here is a step of detecting a nozzle 141 to which foreign matter FO is attached, and corresponds to, for example, steps S101 and S104 shown in Figure 5. The "first cleaning step" is a step of driving the ultrasonic element 530 to transmit ultrasonic waves US to a target area AR including the nozzle opening 141a of the target nozzle 141t to which the foreign matter FO detected in the detection step is attached, and corresponds to, for example, step S105 shown in Figure 5. The "second cleaning step" is a step of driving the wiper 54 after transmitting ultrasonic waves US to wipe the nozzle opening 141a of the target nozzle 141t with the wiper 54, and corresponds to, for example, step S107 shown in Figure 5. In this configuration, the spray surface 142a of the nozzle plate 142 can be wiped off after the foreign matter FO has been sufficiently detached or lifted from the nozzle plate 142. This allows for more reliable removal of foreign matter FO from the nozzle plate 142.

[0036] Furthermore, according to the first embodiment described above, the ultrasonic device 53 is positioned opposite the spray surface 142a of the nozzle plate 142 when cleaning the liquid spray head 14, and is fixed to a cap 52 capable of covering the spray surface 142a of the nozzle plate 142. Therefore, with the spray surface 142a of the nozzle plate 142 covered by the cap 52, ultrasonic waves US can be transmitted to the ink IN contained within the cap 52, causing the ink IN inside the cap 52 to vibrate, thereby transmitting ultrasonic waves US towards the nozzle plate 142. At this time, the cleaning device 50 moves the ultrasonic device 53 in the direction DM along the nozzle row NR, and when it reaches a position where ultrasonic waves US can be transmitted to the target area AR, it drives the ultrasonic element 530 to transmit ultrasonic waves US to the target area AR. Since the wiper 54 is fixed to the cap 52 so as to move in accordance with the ultrasonic device 53, it can wipe over the nozzle opening 141a of the target nozzle 141t after the transmission of ultrasonic waves US.

[0037] Furthermore, according to the first embodiment described above, the wiper 54 is fixed to the cap 52, and the spray surface 142a of the nozzle plate 142 can be wiped in the liquid LQ inside the cap 52. In this configuration, after wiping with the wiper 54, the liquid LQ inside the cap 52 can be discharged outside the cap 52 by sucking it out with a pump (not shown), thereby easily discharging any foreign matter FO removed from the nozzle plate 142 to the liquid spray system 1.

[0038] Furthermore, according to the first embodiment described above, the liquid injection device 10 includes a control device 15 that functions as an injection control unit 151 that controls each part of the liquid injection device 10 and a cleaning control unit 155 that controls each part of the cleaning device 50. With this configuration, the driving of each device of the liquid injection system 1, such as the liquid injection device 10 and the cleaning device 50, can be integrated and managed.

[0039] Furthermore, at least some of the functions of the control device 15 may be implemented as a function of the cleaning device 50. Also, at least some of the functions of the control device 15 may be implemented as a function of any device outside the liquid injection system 1, for example, as a function of a server installed in a business premises that uses the liquid injection system 1.

[0040] B. Second Embodiment: Figure 6 is a diagram illustrating a cleaning method for the liquid spray head 14 in a second embodiment. In this embodiment, the cleaning device 50a comprises a detection unit 51, a cap 52, an ultrasonic device 53a, a wiper 54a, and a cleaning control unit 155a. The ultrasonic device 53a has at least one channel 535 in which a plurality of ultrasonic elements 530, each corresponding to a plurality of nozzles 141, are arranged in a row. Without moving inside the cap 52, the ultrasonic device 53a sequentially drives the ultrasonic elements 530 corresponding to the target nozzles 141t based on control signals received from the cleaning control unit 155a. As a result, the ultrasonic device 53a transmits ultrasonic waves US to the target area AR. The wiper 54 moves along the channel 535 based on control signals received from the cleaning control unit 155a. The cleaning control unit 155a generates control signals to sequentially drive the ultrasonic elements 530 corresponding to the target nozzles 141t and transmits them to the ultrasonic device 53a. The cleaning control unit 155a then generates a control signal to drive the wiper 54 and transmits it to the wiper 54a after transmitting ultrasonic waves toward the nozzle plate 142. The other configurations are the same as in the first embodiment unless otherwise specified. Components identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.

[0041] According to the second embodiment described above, the cleaning device 50a includes a cleaning control unit 155a within the cleaning device 50a, which acts as a control unit for controlling the driving of the ultrasonic device 53a and the wiper 54a. In this configuration, various processes for cleaning the liquid spray head 14 can be completed within the cleaning device 50a.

[0042] Furthermore, according to the second embodiment described above, the ultrasonic device 53a has at least one channel 535 in which a plurality of ultrasonic elements 530 corresponding to a plurality of nozzles 141 are arranged in a row. As a result, the cleaning device 50a can transmit ultrasonic waves US to the target area AR by sequentially driving the ultrasonic elements 530 corresponding to the target nozzles 141t without moving the ultrasonic device 53a inside the cap 52. In addition, the cleaning device 50a can wipe the nozzle opening 141a of the target nozzles 141t after transmitting ultrasonic waves US by driving the wiper 54a according to the driving timing of each ultrasonic element 530.

[0043] C. Third Embodiment: Figure 7 is a diagram illustrating an example of a cleaning method for the liquid spray head 14 in the third embodiment. Figure 8 is a diagram illustrating another example of a cleaning method for the liquid spray head 14 in the third embodiment. Figure 9 is a diagram illustrating yet another example of a cleaning method for the liquid spray head 14 in the third embodiment. Figure 10 is a diagram illustrating yet another example of a cleaning method for the liquid spray head 14 in the third embodiment. In this embodiment, the cleaning devices 50b-50e include a detection unit 51, a cap 52, an ultrasonic device 53b-53e, a wiper 54a, and a cleaning control unit 155b-155e. Note that the detection unit 51, cap 52, and wiper 54a are not shown in Figures 7 to 10. The cleaning control unit 155b-155e may be implemented as a function of the cleaning devices 50b-50e, or as a function of another device other than the cleaning devices 50b-50e.

[0044] In this embodiment, the ultrasonic devices 53b-53e have a plurality of ultrasonic elements 530. The ultrasonic devices 53b-53e are driven as follows based on control signals received from the cleaning control units 155b-155e. The ultrasonic devices 53b-53e drive each of the plurality of ultrasonic elements 530 so that the composite wave CW of ultrasonic US transmitted from each of the plurality of ultrasonic elements 530 is focused on the target area AR. As a result, the ultrasonic devices 53b-53e transmit ultrasonic US more intensively to the target area AR. The cleaning control units 155b-155e generate control signals to drive each of the plurality of ultrasonic elements 530 so that the composite wave CW of ultrasonic US transmitted from each of the plurality of ultrasonic elements 530 is focused on the target area AR, and transmit these signals to the ultrasonic devices 53b-53e. The other configurations are the same as in the first embodiment unless otherwise specified. Components identical to those in the above embodiments are denoted by the same reference numerals and their descriptions are omitted.

[0045] Figure 7 illustrates a method for focusing ultrasonic waves (US) onto a target area (AR) by electrically controlling the driving timing of multiple ultrasonic elements (530). In the example shown in Figure 7, the multiple ultrasonic elements (530) are arranged in a single line along the nozzle row NR so as to face the nozzle row NR when the nozzle row NR to be cleaned is capped. The cleaning control unit (155b) generates a control signal that causes ultrasonic elements (530) that are farther from the target area (AR) to transmit ultrasonic waves (US) earlier, and ultrasonic elements (530) that are closer to the target area (AR) to transmit ultrasonic waves (US) later, and transmits this signal to the ultrasonic device (53b). By creating a time difference in the transmission timing of the ultrasonic waves (US) transmitted from each of the multiple ultrasonic elements (530) in this way, the ultrasonic waves (US) can be focused onto the target area (AR), and the composite wave (CW) can be focused onto the target area (AR). In particular, in the example shown in Figure 7, the multiple ultrasonic elements (530) are arranged in a single line along the nozzle row NR so as to face the nozzle row NR. Therefore, by controlling the driving timing of the multiple ultrasonic elements (530) according to the distance to the target area (AR), the direction of convergence of ultrasonic waves (US) can be changed for each target area (AR) within the nozzle row NR. This makes it possible to focus ultrasonic waves US sequentially from one end to the other on a target region AR within the nozzle row NR, for example, without moving the ultrasonic element 530 along the nozzle row NR.

[0046] Figure 8 illustrates an example of a method for focusing ultrasonic waves (US) onto a target area (AR) using a lens. In the example shown in Figure 8, the multiple ultrasonic elements 530 are arranged in a single row along the nozzle row NR, facing the nozzle row NR when the nozzle row NR to be cleaned is capped. A cylindrical lens CL is positioned adjacent to the multiple ultrasonic elements 530. This cylindrical lens CL can focus ultrasonic waves (US) in a one-dimensional direction along the formation direction of the nozzle row NR. The cylindrical lens CL has a curved surface CLa that protrudes toward the nozzle plate 142 when the nozzle row NR to be cleaned is capped, and a flat surface CLb connected to the curved surface CLa. The cleaning control unit 155c generates a control signal to simultaneously drive the multiple ultrasonic elements 530 and transmits it to the ultrasonic device 53c. As a result, the ultrasonic waves (US) transmitted simultaneously from the multiple ultrasonic elements 530 are incident on the flat surface CLb of the cylindrical lens CL, refracted at the curved surface CLa of the cylindrical lens CL, and emitted. In this way, by physically refracting the ultrasonic waves US transmitted from each of the multiple ultrasonic elements 530 in a one-dimensional direction, the ultrasonic waves US can be focused onto the target region AR, and the composite wave CW can be focused onto the target region AR.

[0047] Figure 9 illustrates another example of a method for focusing ultrasonic waves (US) using a lens. In the example shown in Figure 9, multiple ultrasonic elements 530 are arranged to face the nozzle row NR when the nozzle row NR to be cleaned is capped. A spherical lens SL is then arranged adjacent to the multiple ultrasonic elements 530. This spherical lens SL can focus ultrasonic waves (US) in a two-dimensional direction along the direction in which the nozzle row NR is formed, and an orthogonal direction perpendicular to the direction in which the nozzle row NR is formed, and perpendicular to the direction in which the ultrasonic device 53d and the nozzle plate 142 face each other. The spherical lens SL has a curved surface SLa that protrudes toward the nozzle plate 142 when the nozzle row NR to be cleaned is capped, and a flat surface SLb connected to the curved surface SLa. The cleaning control unit 155d generates a control signal to simultaneously drive the multiple ultrasonic elements 530 and transmits it to the ultrasonic device 53d. As a result, ultrasonic waves US transmitted simultaneously from multiple ultrasonic elements 530 enter the flat surface SLb of the spherical lens SL, are refracted on the curved surface SLa of the spherical lens SL, and exit. In this way, by physically refracting the ultrasonic waves US transmitted from each of the multiple ultrasonic elements 530 in a two-dimensional direction, the ultrasonic waves US can be focused onto the target region AR, and the composite wave CW can be focused onto the target region AR.

[0048] Figure 10 illustrates a method for focusing ultrasonic waves (US) onto the target area (AR) by utilizing the arrangement of multiple ultrasonic elements 530. In the example shown in Figure 10, the multiple ultrasonic elements 530 are arranged along the nozzle row NR so as to face the nozzle row NR when the nozzle row NR to be cleaned is capped. Of the multiple ultrasonic elements 530, the ultrasonic elements 530 located closer to the center are at a greater distance from the target area (AR), while the ultrasonic elements 530 located at both ends are at a smaller distance from the target area (AR). The cleaning control unit 155e generates a control signal to simultaneously drive the multiple ultrasonic elements 530 and transmits it to the ultrasonic device 53e. This creates a difference in the time it takes for the ultrasonic waves (US) transmitted from each of the multiple ultrasonic elements 530 to reach the target area (AR). By creating this difference in the time required for the ultrasonic waves (US) transmitted from each of the multiple ultrasonic elements 530 to reach the target area (AR), the ultrasonic waves (US) can be focused onto the target area (AR), and the composite wave (CW) can be focused onto the target area (AR).

[0049] According to the third embodiment described above, the cleaning devices 50b-50e can drive each of the multiple ultrasonic elements 530 so that the combined wave CW of ultrasonic waves US transmitted from each of the multiple ultrasonic elements 530 is focused on the target area AR. In this configuration, ultrasonic waves US can be transmitted more intensively to the target area AR. This makes it possible to more reliably detach or lift foreign matter FO from the spray surface 142a of the nozzle plate 142 and the inner wall 141b of the nozzle. Therefore, foreign matter FO can be removed from the nozzle plate 142 more reliably.

[0050] Furthermore, according to the third embodiment described above, the cleaning devices 50b-50e can focus the composite wave CW onto the target area AR by electrical control and arrangement of the multiple ultrasonic elements 530, or by refraction of the ultrasonic waves US by a lens. The cleaning devices 50b-50e may also focus the composite wave CW onto the target area AR by methods other than those described above.

[0051] D. Fourth Embodiment: Figure 11 is a diagram illustrating a method for cleaning the liquid spray head 14 in a fourth embodiment. In this embodiment, the cleaning device 50f includes a detection unit 51, a support member 59, an ultrasonic device 53f, and a wiper 54f. The cleaning control unit 155f may be implemented as a function of the cleaning device 50f, or as a function of another device other than the cleaning device 50f.

[0052] The wiper 54f is fixed to a support member 59 so as to be movable along the nozzle row NR. The support member 59 may be a cap 52 or something other than a cap 52. The ultrasonic device 53f is fixed to the wiper 54f. As a result, the ultrasonic device 53f and the wiper 54f move together while vibrating along the nozzle row NR. The ultrasonic device 53f vibrates the wiper 54f by transmitting ultrasonic waves US to the wiper 54f when the wiper 54f is in contact with the nozzle plate 142. As a result, the ultrasonic device 53f can transmit ultrasonic waves US toward the nozzle plate 142. Based on the control signal received from the cleaning control unit 155f, the ultrasonic device 53f drives the ultrasonic element 530 at least before the wiper 54f reaches the nozzle opening 141a of the target nozzle 141t. As a result, the ultrasonic device 53f transmits ultrasonic waves US to the target area AR before the wiper 54f wipes over the nozzle opening 141a of the target nozzle 141t. In this manner, after the ultrasonic US is transmitted, the wiper 54f wipes over the nozzle opening 141a of the target nozzle 141t.

[0053] According to the fourth embodiment described above, the ultrasonic device 53f is fixed to the wiper 54f. This allows ultrasonic waves US to be transmitted from the ultrasonic device 53f to the wiper 54f while the wiper 54f is in contact with the nozzle plate 142, causing the wiper 54f to vibrate and thereby transmitting ultrasonic waves US towards the nozzle plate 142. In this configuration, the nozzle plate 142 can be directly vibrated, so ultrasonic waves US can be transmitted to the nozzle plate 142 without the need for liquid LQ. This allows the liquid spray head 14 to be cleaned without containing liquid LQ in the cap 52. Therefore, the time and cost required for cleaning the liquid spray head 14 can be reduced.

[0054] In addition, in the fourth embodiment described above, as in the embodiments from the first to the third embodiment, ultrasonic waves (US) may be transmitted to the nozzle plate 142 via a liquid (LQ) such as ink (IN).

[0055] E. Other embodiments: E-1. Other Embodiments 1: In each of the above embodiments, when the diameter of the nozzle 141 is D [μm], the frequency of the ultrasonic wave US transmitted by the ultrasonic device 53 may be 6 / D [MHz] or higher. For example, when the diameter of the nozzle 141 is 20 [μm], the frequency of the ultrasonic wave US transmitted by the ultrasonic device 53 may be 0.3 [MHz] or higher. With such a configuration, the nozzle plate 142 can be ultrasonically cleaned more effectively. This allows for more reliable removal or lifting of foreign matter FO from the spray surface 142a and the inner wall 141b of the nozzle plate 142. Therefore, foreign matter FO can be removed from the nozzle plate 142 more reliably. Note that setting the ultrasonic wave frequency to 6 / D [MHz] is particularly effective when focusing the composite wave CW onto the target area AR.

[0056] E-2. Other Embodiments 2: The liquid ejection device 10 may be something other than an inkjet printer. If the liquid ejection device 10 is something other than an inkjet printer, the term "ink" in this disclosure may be replaced with "liquid" as appropriate.

[0057] E-3. Other Embodiments 3: In each of the above embodiments, at least a portion of the configuration implemented by hardware may be implemented by software, and conversely, at least a portion of the configuration implemented by software may be implemented by hardware.

[0058] F. Other forms: This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features of the embodiments corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate.

[0059] (1) According to one embodiment of the present disclosure, a cleaning device for a liquid spray head is provided. In the cleaning device for a liquid spray head, the liquid spray head has a nozzle plate on which a plurality of nozzles for spraying liquid are formed, a pressure chamber communicating with the nozzles, a diaphragm defining a part of the pressure chamber, and a piezoelectric element laminated on the diaphragm, the cleaning device comprises an ultrasonic device having an ultrasonic element that transmits ultrasonic waves toward the nozzle plate, a wiper that wipes the spray surface of the nozzle plate, and a detection unit that detects the nozzles to which foreign matter is attached, the ultrasonic device drives the ultrasonic element so that ultrasonic waves are transmitted to a target region which is the region including the nozzle opening of the target nozzle that is the nozzle to which the foreign matter is attached as detected by the detection unit, and the wiper wipes over the nozzle opening of the target nozzle after the transmission of the ultrasonic waves. According to this embodiment, ultrasonic waves can be transmitted locally toward a target region including the nozzle opening of the target nozzle that is to which foreign matter is attached, without uniformly transmitting ultrasonic waves toward the spray surface of the nozzle plate. In this configuration, bubbles generated by cavitation can be concentrated in the target area. Therefore, the likelihood of these bubbles colliding with foreign matter can be increased. As a result, foreign matter can be sufficiently detached or lifted from the nozzle plate's spray surface and the nozzle's inner wall. Furthermore, with this configuration, after transmitting ultrasonic waves towards the nozzle plate, the nozzle opening of the target nozzle can be wiped with a wiper. In this configuration, after the foreign matter has been sufficiently detached or lifted from the nozzle plate, the spray surface of the nozzle plate can be wiped clean. As a result, foreign matter can be removed from the nozzle plate more reliably.

[0060] (2) In the above embodiment, the ultrasonic device is fixed to the wiper, and the ultrasonic device can transmit the ultrasonic waves toward the nozzle plate by transmitting ultrasonic waves to the wiper while the wiper is in contact with the nozzle plate, causing the wiper to vibrate, and the ultrasonic device may drive the ultrasonic element at least before the wiper reaches the nozzle opening of the target nozzle. In this embodiment, the ultrasonic device is fixed to the wiper. This allows ultrasonic waves to be transmitted toward the nozzle plate by transmitting ultrasonic waves from the ultrasonic device to the wiper while the wiper is in contact with the nozzle plate, causing the wiper to vibrate. With this embodiment, the nozzle plate can be directly vibrated, so ultrasonic waves can be transmitted to the nozzle plate without the need for liquid. This allows the liquid spray head to be cleaned without the need to contain liquid in the cap. Therefore, the time and cost required for cleaning the liquid spray head can be reduced.

[0061] (3) In the above embodiment, the device may further include a control unit that controls the driving of the ultrasonic device and the wiper. In this embodiment, various processes for cleaning the liquid spray head can be completed within the cleaning device.

[0062] (4) In the above embodiment, the ultrasonic device is further provided with a cap positioned opposite the spray surface and capable of covering the spray surface, the ultrasonic device is fixed to the cap, and the ultrasonic device can transmit the ultrasonic waves toward the nozzle plate by transmitting the ultrasonic waves to the liquid contained in the cap while the spray surface is covered by the cap, thereby vibrating the liquid in the cap, the ultrasonic device has at least one channel in which a plurality of ultrasonic elements corresponding to the plurality of nozzles are arranged in a row, the wiper moves along the channel, and the control unit may transmit the ultrasonic waves to the target area by sequentially driving the ultrasonic elements corresponding to the target nozzle. In this embodiment, the ultrasonic device has at least one channel in which a plurality of ultrasonic elements corresponding to the plurality of nozzles are arranged in a row. As a result, ultrasonic waves can be transmitted to the target area by sequentially driving the ultrasonic elements corresponding to the target nozzle. In addition, by driving the wiper according to the driving timing of each ultrasonic element, the nozzle opening of the target nozzle can be wiped after the ultrasonic waves have been transmitted.

[0063] (5) In the above embodiment, the device further includes a cap positioned opposite the spray surface and capable of covering the spray surface, the ultrasonic device is fixed to the cap, and the ultrasonic device can transmit ultrasonic waves toward the nozzle plate by transmitting ultrasonic waves to the liquid contained in the cap while the spray surface is covered by the cap, thereby vibrating the liquid in the cap, the ultrasonic device has a plurality of ultrasonic elements, and the control unit may transmit ultrasonic waves toward the target area by driving each of the plurality of ultrasonic elements so that the composite wave of ultrasonic waves transmitted from each of the plurality of ultrasonic elements is focused on the target area. In this embodiment, each of the plurality of ultrasonic elements can be driven so that the composite wave of ultrasonic waves transmitted from each of the plurality of ultrasonic elements is focused on the target area. With this embodiment, ultrasonic waves can be transmitted more concentratedly to the target area. This makes it possible to more reliably detach or lift foreign matter from the spray surface of the nozzle plate or the inner wall of the nozzle. Therefore, foreign matter can be removed from the nozzle plate more reliably.

[0064] (6) In the above embodiment, when the diameter of the nozzle is D [μm], the frequency of the ultrasonic wave may be 6 / D [MHz] or higher. This embodiment allows for more suitable ultrasonic cleaning of the nozzle plate. This makes it possible to more reliably detach or lift foreign matter from the spray surface of the nozzle plate and the inner wall of the nozzle. Therefore, foreign matter can be removed from the nozzle plate more reliably.

[0065] (7) Another embodiment of the present disclosure provides a method for cleaning a liquid spray head. The method for cleaning a liquid spray head having a nozzle plate on which a plurality of nozzles for spraying liquid are formed comprises: a detection step of detecting a nozzle to which foreign matter is attached; a first cleaning step of driving an ultrasonic element to transmit ultrasonic waves to a target area which is the area including the nozzle opening of the target nozzle to which the foreign matter detected in the detection step is attached; and a second cleaning step of driving a wiper after transmitting the ultrasonic waves to wipe the nozzle opening of the target nozzle with the wiper. In this embodiment, the liquid spray head can be cleaned by performing the detection step, the first cleaning step and the second cleaning step. In this case, in the first cleaning step, ultrasonic waves can be transmitted locally to the target area which is the area including the nozzle opening of the target nozzle to which foreign matter is attached, rather than uniformly transmitting ultrasonic waves toward the spray surface of the nozzle plate. In this embodiment, bubbles due to cavitation can be concentrated and generated in the target area. Therefore, the possibility of bubbles generated by cavitation colliding with foreign matter can be increased. Therefore, foreign matter can be sufficiently detached or lifted from the spray surface of the nozzle plate and the inner wall of the nozzle. Furthermore, in the second cleaning step, after transmitting ultrasonic waves towards the nozzle plate, the nozzle opening of the target nozzle can be wiped with a wiper. With this configuration, after the foreign matter has been sufficiently detached or lifted from the nozzle plate, the spray surface of the nozzle plate can be wiped clean. Therefore, foreign matter can be removed from the nozzle plate more reliably.

[0066] Not all of the components of each form of the present disclosure described above are essential, and it is possible to modify, delete, replace with other new components, or delete some of the limitations of some of the components as appropriate in order to solve some or all of the problems described above or to achieve some or all of the effects described herein. Furthermore, it is also possible to combine some or all of the technical features included in one form of the present disclosure described above with some or all of the technical features included in another form of the present disclosure described above to form an independent form of the present disclosure in order to solve some or all of the problems described above or to achieve some or all of the effects described herein.

[0067] This disclosure can also be implemented in various forms other than a cleaning device and cleaning method for a liquid spray head. For example, it can be implemented in the form of a liquid spray system comprising a liquid spray head and a cleaning device, a method for manufacturing the cleaning device and the liquid spray system, a method for controlling the cleaning device and the liquid spray system, a computer program for implementing the control method, and a non-temporary recording medium on which the computer program is stored. [Explanation of symbols]

[0068] 1...Liquid injection system, 10...Liquid injection device, 11...Cartridge mounting section, 12...Liquid flow pipe, 13...Carriage, 14...Liquid injection head, 15...Control device, 16...Drive mechanism, 17...Transport mechanism, 20...Cartridge, 50, 50a-50f...Cleaning device, 51...Detection section, 52...Cap, 53, 53a-53f...Ultrasonic device, 54, 54a, 54f...Wiper, 59...Support member, 141...Nozzle, 141a...Nozzle opening, 141b...Nozzle inner wall, 141t...Target nozzle, 142...Nozzle plate, 142a...Injection surface, 143...Pressure chamber, 144...Vibrating plate, 145...Piezoelectric element, 146...Individual flow path, 15 1…Ink spray control unit, 155, 155a-155f…Cleaning control unit, 161…Timing belt, 162…Drive motor, 530…Ultrasonic element, 535…Channel, AR…Target area, C…Cyan, CL…Cylindrical lens, CLa…Curved surface of cylindrical lens, CLb…Flat surface of cylindrical lens, CW…Composite wave, DM…Direction of movement, FO…Foreign matter, HP…Home position, IN…Ink, K…Black, LQ…Liquid, M…Magenta, N…Nozzle number, NR…Nozzle row, SL…Spherical lens, SLa…Curved surface of spherical lens, SLb…Flat surface of spherical lens, TG…Object to be sprayed, US…Ultrasonic, Y…Yellow

Claims

1. A cleaning device for liquid spray heads, The aforementioned liquid spray head is A nozzle plate having multiple nozzles formed for spraying liquid, A pressure chamber communicating with the nozzle, A diaphragm that defines a part of the pressure chamber, The diaphragm has a piezoelectric element laminated on it, The cleaning device is An ultrasonic device having an ultrasonic element that transmits ultrasonic waves toward the nozzle plate, A wiper for wiping the spray surface of the nozzle plate, The system includes a detection unit for detecting the nozzle to which foreign matter has adhered, The ultrasonic device drives the ultrasonic element so that the ultrasonic waves are transmitted to the target region, which is the region including the nozzle opening of the target nozzle, to which the foreign matter detected by the detection unit is attached. The wiper is a cleaning device that wipes the nozzle opening of the target nozzle after the transmission of the ultrasonic waves.

2. A cleaning apparatus according to claim 1, The ultrasonic device is fixed to the wiper, The ultrasonic device can transmit ultrasonic waves toward the nozzle plate by transmitting ultrasonic waves to the wiper while the wiper is in contact with the nozzle plate, thereby causing the wiper to vibrate. The ultrasonic device is a cleaning device that drives the ultrasonic element at least before the wiper reaches the nozzle opening of the target nozzle.

3. A cleaning apparatus according to claim 1, further, A cleaning device comprising the ultrasonic device and a control unit that controls the driving of the wiper.

4. The cleaning apparatus according to claim 3, further, It comprises a cap positioned opposite the spray surface and capable of covering the spray surface, The ultrasonic device is fixed to the cap, The ultrasonic device, with the spray surface covered by the cap, can transmit ultrasonic waves to the liquid contained within the cap, causing the liquid inside the cap to vibrate, thereby transmitting ultrasonic waves toward the nozzle plate. The ultrasonic device has at least one channel in which a plurality of ultrasonic elements, each corresponding to one of the plurality of nozzles, are arranged in a row. The wiper moves along the channel, The control unit sequentially drives the ultrasonic element corresponding to the target nozzle to transmit the ultrasonic waves to the target area, thereby providing a cleaning device.

5. The cleaning apparatus according to claim 3, further, It comprises a cap positioned opposite the spray surface and capable of covering the spray surface, The ultrasonic device is fixed to the cap, The ultrasonic device, with the spray surface covered by the cap, can transmit ultrasonic waves to the liquid contained within the cap, causing the liquid inside the cap to vibrate, thereby transmitting ultrasonic waves toward the nozzle plate. The ultrasonic device has a plurality of ultrasonic elements, The control unit drives each of the plurality of ultrasonic elements so that the combined ultrasonic wave transmitted from each of the plurality of ultrasonic elements is focused on the target area, thereby transmitting the ultrasonic waves to the target area.

6. A cleaning device according to any one of claims 1 to 5, A cleaning device in which, when the diameter of the nozzle is D [μm], the frequency of the ultrasonic waves is 6 / D [MHz] or higher.

7. A method for cleaning a liquid spray head having a nozzle plate formed with multiple nozzles for spraying liquid, A detection step for detecting the nozzle to which foreign matter is attached, A first cleaning step involves driving an ultrasonic element to transmit ultrasonic waves to a target region, which is the area including the nozzle opening of the target nozzle to which the foreign matter detected in the detection step is attached; A cleaning method comprising: a second cleaning step of driving a wiper after transmitting the ultrasonic waves to wipe the nozzle opening of the target nozzle with the wiper.

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