JP2020168753A - Printing device - Google Patents

Abstract

To provide a printing device that can capture a foreign matter.SOLUTION: A printing device 11 comprises a head 28 that performs printing on media 99, a holding part 31 that holds the head, an electrode 33, provided in the holding part, which captures a foreign matter, and a control part 35 that changes a polarity of the electrode between positive and negative. The control part, when the head is charged positively, sets an electric potential of the electrode whose polarity is positive to be larger than an electric potential of the head, and when the head is charged negatively, sets an electric potential of the electrode whose polarity is negative to be larger than the electric potential of the head.SELECTED DRAWING: Figure 1

Description

The present invention relates to a printing apparatus.

Patent Document 1 describes, as an example of a printing device, a fluid injection device including a head for injecting a fluid onto a medium and a foreign matter capturing unit for capturing foreign matter. The foreign matter capturing unit captures foreign matter in the device by being charged. When the foreign matter catching unit catches the foreign matter, the possibility that the foreign matter adheres to the head is suppressed.

Japanese Unexamined Patent Publication No. 2010-167631

In the fluid injection device described in Patent Document 1, it is predetermined whether the foreign matter trapping portion is charged positively or negatively. Therefore, when the foreign matter trapping portion is positively charged, the negatively charged foreign matter can be captured, but the positively charged foreign matter cannot be captured. When the foreign matter trapping portion is negatively charged, it can capture the positively charged foreign matter, but cannot capture the negatively charged foreign matter. As described above, in the fluid injection device described in Patent Document 1, it is difficult to sufficiently capture foreign substances.

A printing device that solves the above problems includes a head that prints on media, a holding portion that holds the head, an electrode that is provided in the holding portion and collects foreign matter, and the polarity of the electrode is positive or negative. The control unit includes a control unit for changing, and when the head is positively charged, the control unit increases the potential of the electrode when the polarity of the electrode is positive to be larger than the potential of the head, and the head When negatively charged, the potential of the electrode when the polarity of the electrode is negative is made larger than the potential of the head.

The side view which shows one Embodiment of a printing apparatus schematically. Sectional view of the printing apparatus. A block diagram of a control unit that functions as a machine learning unit.

Hereinafter, an embodiment of the printing apparatus will be described with reference to the drawings. The printing device is, for example, an inkjet printer that prints images such as characters and photographs by ejecting ink, which is an example of a liquid, onto a medium such as paper.

As shown in FIG. 1, the printing apparatus 11 includes a head 28 for printing on the media 99. The head 28 has one or more nozzles 29 that eject the liquid.
The printing device 11 of the present embodiment includes a housing 12. The housing 12 accommodates the head 28. The printing device 11 includes a base 13 that supports the housing 12. In the present embodiment, the housing 12 is located above the base 13.

The printing device 11 includes a transport unit 14 that transports the media 99. The transport unit 14 is provided, for example, in the housing 12. The transport unit 14 of the present embodiment transports the media 99 placed outside the housing 12 along the transport path 15. In the present embodiment, the direction in which the media 99 is transported by the transport unit 14 is defined as the transport direction D1.

The printing apparatus 11 may include a mounting portion 16 on which the roll body 100 on which the media 99 is wound can be mounted. The mounting portion 16 is attached to, for example, a base 13. The mounting portion 16 rotatably supports the roll body 100 on which the media 99 before the liquid is discharged is wound. When the transport unit 14 is driven, the media 99 is unwound from the roll body 100.

The printing device 11 may be configured to discharge the liquid to the media 99 unwound from the roll body 100 placed on the installation surface on which the printing device 11 is installed. The printing device 11 may have a configuration in which a liquid is discharged to a medium 99 delivered from a device different from the printing device 11. The printing device 11 is not limited to a configuration in which the liquid is discharged to the medium 99 fed from the roll body 100, and may be configured to discharge the liquid to a long medium 99 such as a fan hold paper.

The printing device 11 may include a winding unit 17 that winds up the printed media 99. The take-up portion 17 is attached to, for example, a base 13. The winding unit 17 winds the media 99 on which the liquid is discharged as the roll body 100. The printing device 11 may be configured to transport the medium 99 on which the liquid is discharged to a device different from the printing device 11. The printing device 11 may have a configuration in which the medium 99 on which the liquid is discharged is wound by a device different from the printing device 11.

The printing device 11 may include a tension applying member 18 that applies tension to the media 99. The tension applying member 18 applies tension to the media 99 by coming into contact with the media 99. By applying tension to the media 99 by the tension applying member 18, the liquid can be landed on the media 99 with high accuracy. The tension applying member 18 of the present embodiment comes into contact with a portion of the media 99 that has passed through the head 28.

The tension applying member 18 is attached to, for example, the base 13. The tension applying member 18 may be displaceably attached to the base 13. In this way, the magnitude of the tension applied to the media 99 can be adjusted by displacing the tension applying member 18.

The tension applying member 18 may be displaced so that the tension applied to the media 99 becomes constant. In this case, the tension applying member 18 is displaced according to, for example, the speed at which the winding portion 17 winds the media 99.

A device other than the printing device 11 may apply tension to the media 99. For example, a device other than the printing device 11 may include the tension applying member 18.
The printing apparatus 11 may include a first support portion 21, a second support portion 22, and a third support portion 23. The first support portion 21, the second support portion 22, and the third support portion 23 support the media 99 conveyed by the transfer unit 14. The first support portion 21, the second support portion 22, and the third support portion 23 are located in this order from the upstream to the downstream in the transport direction D1. The second support portion 22 of the present embodiment is located inside the housing 12.

The transport unit 14 of the present embodiment has a first roller 25 and a second roller 26. The first roller 25 and the second roller 26 convey the media 99 by rotating while sandwiching the media 99. The first roller 25 and the second roller 26 are positioned so as to sandwich the media 99 between the first support portion 21 and the second support portion 22 in the transport direction D1.

The printing device 11 includes a holding unit 31 that holds the head 28. The holding portion 31 is formed in a rectangular parallelepiped shape, for example. In the present embodiment, the head 28 is located on the bottom surface of the holding portion 31. The bottom surface of the holding portion 31 is a surface facing the second supporting portion 22. Therefore, the head 28 discharges the liquid to the portion of the media 99 supported by the second support portion 22.

The holding unit 31 of the present embodiment can scan the media 99. That is, the printing device 11 includes, for example, a guide shaft 32 that guides the holding portion 31. The holding portion 31 is movable along the guide shaft 32. The holding portion 31 scans against the media 99 by moving along the guide shaft 32. As described above, the printing device 11 of the present embodiment is a serial printer in which the head 28 scans the media 99. The printing device 11 may be a line printer in which the head 28 is provided in a long length. In this case, the printing device 11 does not have to include the guide shaft 32.

In the present specification, the scanning direction indicates a direction in which the holding portion 31 moves along the guide shaft 32. Therefore, the scanning direction indicates both directions extending parallel to the guide shaft 32.
The printing device 11 includes an electrode 33 that collects foreign matter. The electrode 33 is provided on the holding portion 31. When the electrode 33 is energized, the polarity of the electrode 33 is positive or negative. That is, the electrode 33 is positively or negatively charged when it is energized. The energized electrode 33 collects the foreign matter by attracting the charged foreign matter. For example, when the polarity of the electrode 33 is positive, a negatively charged foreign substance is attracted to the electrode 33. When the polarity of the electrode 33 is negative, a positively charged foreign substance is attracted to the electrode 33. In this way, the electrode 33 collects foreign matter in the housing 12.

The foreign matter is, for example, dust in the atmosphere, dust generated from the media 99, or the like. These foreign objects may be charged. When the foreign matter is charged, it easily adheres to other members. In the housing 12, foreign matter may adhere to the head 28.

The head 28 of this embodiment is grounded. Therefore, the potential of the head 28 is set to 0. When a charged foreign matter approaches the head 28, a charge having a polarity opposite to that of the foreign matter appears on the surface of the head 28. As a result, a Coulomb force is generated between the surface of the head 28 and the foreign matter. This makes it easier for foreign matter to adhere to the head 28.

If foreign matter adheres to the head 28, the liquid may not be discharged normally from the nozzle 29. The fact that the liquid is not normally discharged from the nozzle 29 is called nozzle omission. If the nozzle is missing, printing may not be performed normally. Therefore, the electrode 33 collects the foreign matter, thereby suppressing the foreign matter from adhering to the head 28.

The electrode 33 of the present embodiment is provided on the side surface 31A of the holding portion 31 in the scanning direction. In other words, the electrode 33 is provided on the side surface 31A, which is the side surface of the holding unit 31 facing any one of the scanning directions of the holding unit 31. If the electrode 33 is provided on the bottom surface of the holding portion 31, foreign matter collects between the second supporting portion 22 and the holding portion 31, so that there is a high possibility that the electrode 33 will adhere to the head 28. By providing the electrode 33 on the side surface 31A of the holding portion 31, foreign matter is collected at a position farther from the head 28 than when it is provided on the bottom surface. Therefore, the possibility that foreign matter adheres to the head 28 is reduced.

The electrode 33 of this embodiment is located upstream of the head 28 in the transport direction D1. In this case, the media 99 approaches the electrode 33 before the conveyed media 99 reaches a position facing the head 28. As a result, foreign matter adhering to the media 99, foreign matter generated from the media 99, and the like can be collected by the electrode 33 before the media 99 is printed.

The printing device 11 includes a control unit 35 that controls the polarity of the electrode 33. The control unit 35 changes the polarity of the electrode 33 between positive and negative. The control unit 35 changes the polarity of the electrode 33 through, for example, a booster circuit. By changing the polarity of the electrode 33, both positively charged foreign matter and negatively charged foreign matter can be collected by the electrode 33.

The head 28 does not have to be grounded. In this case, the head 28 may be charged. Therefore, the control unit 35 controls the polarity of the electrode 33 so that the electrode 33 has a potential larger than the potential of the head 28 in order to collect foreign matter. For example, when the head 28 is positively charged, the potential of the electrode 33 when the polarity is positive is made larger than that of the head 28. In this way, the force of the positively charged electrode 33 to attract the negatively charged foreign matter is greater than the force of the positively charged head 28 to attract the negatively charged foreign matter. As a result, the negatively charged foreign matter is attracted to the electrode 33.

When the head 28 is negatively charged, the potential of the electrode 33 when the polarity is negative is made larger than that of the head 28. In this way, the force of the negatively charged electrode 33 to attract the positively charged foreign matter is greater than the force of the negatively charged head 28 to attract the positively charged foreign matter. As a result, positively charged foreign matter is attracted to the electrode 33. When the head 28 is not grounded, the printing device 11 includes a detection unit that detects the potential of the head 28. The large potential means a large potential in absolute value.

As described above, the control unit 35 changes the polarity of the electrode 33 between positive and negative. When the head 28 is positively charged, the control unit 35 makes the potential of the electrode 33 when the polarity of the electrode 33 is positive larger than the potential of the head 28. When the head 28 is negatively charged, the control unit 35 makes the potential of the electrode 33 when the polarity of the electrode 33 is negative larger than the potential of the head 28. That is, when the polarity of the electrode 33 is positive, negatively charged foreign matter can be collected. When the polarity of the electrode 33 is negative, positively charged foreign matter can be collected. As a result, both negatively charged foreign matter and positively charged foreign matter can be collected.

The control unit 35 of the present embodiment comprehensively controls the printing apparatus 11. The control unit 35 is composed of, for example, a CPU, a memory, and the like. The control unit 35 controls the printing device 11 by executing a program stored in the memory by the CPU.

The control unit 35 may control the polarity of the electrode 33 based on the media type information indicating the information of the media 99. The media type information is stored in, for example, the control unit 35. The media type information includes information related to the charging sequence of the media 99. As a result, the control unit 35 can determine whether the media 99 to be used is likely to be charged, positive or negative, based on the media type information. The control unit 35 of the present embodiment stores media type information for each type of media 99 such as paper, cloth, and film.

In the present embodiment, the first support portion 21, the second support portion 22, and the third support portion 23 are made of an aluminum material or a SUS material. Therefore, from the type of the media 99 and the materials constituting the first support portion 21, the second support portion 22, and the third support portion 23, the first support portion 21, the second support portion 22, and the third support portion 23 are used. It is possible to predict whether the media 99 will be charged positively or negatively due to the friction of the media 99.

The control unit 35 may determine whether the media 99 is likely to be charged, positive or negative, based on the media type information. As a control of the polarity of the electrode 33, the control unit 35 may change the polarity of the electrode 33 to a negative value when it is determined that the media 99 is likely to be positively charged. As a control of the polarity of the electrode 33, the control unit 35 may change the polarity of the electrode 33 to positive when it is determined that the media 99 is likely to be negatively charged. The polarities of the foreign matter adhering to the media 99 and the foreign matter generated from the media 99 tend to be the same as the polarity of the media 99. Therefore, when the control unit 35 changes the polarity of the electrode 33 as described above, foreign matter adhering to the media 99 and foreign matter generated from the media 99 can be effectively collected.

The control unit 35 may acquire the media type information from the server. The server is a computer connected to the printing device 11 via a network. In the server, the media type information is updated as appropriate. Therefore, in this case, the polarity of the electrode 33 can be controlled based on the latest media type information.

The printing device 11 may include a blowing mechanism 37 that sends air from the outside of the housing 12 into the housing 12. The blower mechanism 37 has a flow path 38 that leads to the outside of the housing 12 and the inside of the housing 12. The blower mechanism 37 sends the atmosphere from the outside of the housing 12 into the housing 12 through the flow path 38.

The blower mechanism 37 has a fan 39. The fan 39 is located in the flow path 38. When the fan 39 is driven, the atmosphere is sent from the outside of the housing 12 into the housing 12 through the flow path 38. In this way, the ventilation mechanism 37 ventilates the inside of the housing 12. By ventilating, it is possible to prevent the inside of the housing 12 from becoming highly humid due to the liquid discharged from the head 28.

The control unit 35 may control the polarity of the electrode 33 based on the amount of air blown by the air blowing mechanism 37 and the media type information. When the blower mechanism 37 sends the atmosphere from the outside of the housing 12 into the housing 12, foreign substances in the atmosphere enter the housing 12 together with the atmosphere. Therefore, if the amount of air blown by the air blowing mechanism 37 is large, the amount of foreign matter entering the housing 12 increases. When the amount of air blown by the air blowing mechanism 37 is small, the amount of foreign matter entering the housing 12 is small. It is difficult to predict whether many foreign substances in the atmosphere are positively charged or negatively charged. Further, even if it can be foreseen, which of the positively charged foreign matter and the negatively charged foreign matter is more depends largely on the environment in which the printing apparatus 11 is installed. Therefore, when the amount of air blown by the blower mechanism 37 is large, the ratio of foreign matter generated from the media 99 to the foreign matter existing in the housing 12 is smaller than when the amount of air blown by the blower mechanism 37 is small. Therefore, the relationship between the polarity tendency of the foreign matter in the housing 12 and the media type information is relatively low. On the other hand, when the amount of air blown by the air blowing mechanism 37 is small, the relationship between the polarity tendency of the foreign matter in the housing 12 and the media type information is relatively high. Therefore, by controlling the polarity of the electrode 33 based on the amount of air blown by the air blowing mechanism 37 and the media type information, foreign matter in the housing 12 can be effectively collected. For example, the control unit 35 does not change the polarity of the electrode 33 based on the media type information when the amount of air blown by the blower mechanism 37 is higher than the predetermined threshold value, and when the amount of air blown by the blower mechanism 37 is lower than the predetermined threshold value, By changing the polarity of the electrode 33 based on the media type information, foreign matter can be collected more effectively.

The amount of air blown by the air blowing mechanism 37 is, for example, the number of revolutions per unit time of the fan 39. The control unit 35 grasps the amount of air blown based on, for example, the value of the current flowing through the motor that drives the fan 39.

The printing device 11 may include a measuring device 41 that measures the amount of foreign matter sent into the housing 12 by the blowing mechanism 37. The measuring instrument 41 is located, for example, in the flow path 38. The measuring instrument 41 irradiates light in the flow path 38, for example, and measures the amount of foreign matter as a measured value from the transmittance of the light. The measuring instrument 41 of the present embodiment is located downstream of the fan 39 in the direction in which the atmosphere flows through the flow path 38. By doing so, the amount of foreign matter entering the housing 12 can be appropriately measured by the blower mechanism 37.

The control unit 35 may control the polarity of the electrode 33 based on the amount of foreign matter measured by the measuring instrument 41 and the media type information. By controlling the polarity of the electrode 33 based on the amount of foreign matter entering the housing 12 and the media type information, the foreign matter in the housing 12 can be effectively collected. For example, the same control as the above-mentioned ventilation amount and media type information by the ventilation mechanism 37 is possible.

The printing device 11 may include a detector 42 that detects the humidity outside the housing 12. The detector 42 detects the humidity in the atmosphere in which the printing device 11 is installed, that is, the humidity in the atmosphere outside the housing 12. The detector 42 may detect the relative humidity of the atmosphere or may detect the absolute humidity of the atmosphere.

The detector 42 of this embodiment is located in the flow path 38. In this way, the humidity of the atmosphere sent by the fan 39 can be effectively detected. The detector 42 may be provided at a position where the humidity of the atmosphere can be detected, and may be attached to the base 13, for example.

When the humidity of the atmosphere is high, foreign substances in the atmosphere are less likely to float. Therefore, the amount of foreign matter entering the housing 12 is smaller when the atmospheric humidity is high than when the atmospheric humidity is low. On the other hand, when the humidity of the atmosphere is high, the amount of water contained in the roll body 100 increases. When the head 28 discharges the liquid to the media 99 having a large amount of water, the liquid may not be easily fixed to the media 99, or the liquid may bleed to the media 99. That is, the print quality may deteriorate.

The printing device 11 may include a preheater 43 that heats the media 99 before printing. When the preheater 43 heats the media 99, the media 99 before printing is dried. That is, even when the humidity of the atmosphere is high, the amount of water contained in the media 99 is reduced. As a result, printing can be performed properly even when the humidity of the atmosphere is high.

The control unit 35 may control the output of the preheater 43 based on the humidity detected by the detector 42. When the humidity of the atmosphere is high, the amount of water contained in the media 99 is large, and when the humidity of the atmosphere is low, the amount of water contained in the media 99 is small. Therefore, for example, the output of the preheater 43 may be increased when the humidity of the atmosphere is high, and the output of the preheater 43 may be decreased when the humidity of the atmosphere is low. In this way, the media 99 can be appropriately dried based on the amount of water contained in the media 99 before printing.

The preheater 43 of the present embodiment is located upstream of the position where the liquid is discharged by the head 28 in the transport direction D1. The preheater 43 heats the media 99 in the transport direction D1 upstream of the position where the liquid is discharged by the head 28. The preheater 43 is, for example, a sheet-shaped heater. The preheater 43 is attached to the first support portion 21. The preheater 43 is attached to the first support portion 21 on the back surface opposite to the front surface in contact with the media 99. The heat of the preheater 43 is transferred to the media 99 via the first support portion 21.

The control unit 35 controls the polarity of the electrode 33 based on the humidity detected by the detector 42 and the media type information in the printing device 11 including the preheater 43 whose output is controlled according to the humidity of the atmosphere. May be good. When the humidity of the atmosphere is high, it is difficult for foreign substances in the atmosphere to enter the housing 12 as compared with the case where the humidity of the atmosphere is low. On the other hand, since the media 99 is heated by the preheater 43 whose output is controlled according to the humidity of the atmosphere, the amount of foreign matter generated from the media 99 is not easily affected by the humidity of the atmosphere. Therefore, when the humidity of the atmosphere is high, the ratio of the foreign matter generated from the media 99 to the foreign matter existing in the housing 12 is larger than that when the humidity of the atmosphere is low. Therefore, for example, when the humidity is high, foreign matter in the housing 12 is effectively captured by controlling the electrode 33 so that the polarity is opposite to the polarity of the media 99 that is easily charged based on the media type information. Can be collected.

The printing device 11 may include an afterheater 44 that heats the media 99 after printing. The afterheater 44 is located downstream of the position where the liquid is discharged by the head 28 in the transport direction D1. The afterheater 44 heats the media 99 in the transport direction D1 downstream of the position where the liquid is discharged by the head 28. As a result, the media 99 to which the liquid is discharged by the head 28 can be dried.

The after heater 44 has, for example, a heater tube 45. The heater tube 45 extends over the width of the media 99. In this embodiment, two heater tubes 45 are provided. The heater tube 45 is located in the third support portion 23 so as to face the surface which is the surface in contact with the media 99.

The control unit 35 may control the output of the afterheater 44 based on the amount of liquid discharged by the head 28 to the media 99. When the amount of liquid discharged is large, the amount of water contained in the media 99 after printing increases. Therefore, for example, the output of the afterheater 44 may be increased when the liquid discharge amount is large, and the output of the afterheater 44 may be decreased when the liquid discharge amount is small. In this way, the printed media 99 can be appropriately dried.

Even if the polarity of the foreign matter generated from the media 99 is predicted based on the media type information, it is difficult to predict the polarity of the foreign matter existing in the atmosphere. Therefore, the control unit 35 changes the polarity of the electrode 33 at a predetermined timing. For example, when the holding unit 31 reciprocates with respect to the media 99, the control unit 35 controls so that the polarity of the electrode 33 becomes positive when moving on the outward path and the polarity of the electrode 33 becomes negative when moving on the return path. You may. In this way, both positively charged foreign matter and negatively charged foreign matter can be collected.

The control unit 35 of the present embodiment changes the polarity of the electrode 33 when the holding unit 31 is located at a position not facing the media 99. This is because if the polarity of the electrode 33 is changed at a position facing the media 99, foreign matter collected by the electrode 33 may fall onto the media 99. Therefore, for example, when the holding portion 31 is located at the end of the guide shaft 32, the polarity of the electrode 33 is changed. The polarity of the electrode 33 may be changed when the movement of the holding portion 31 is switched between the outward path and the return path.

Assuming that the holding portion 31 that reciprocates in the scanning direction moves one way in one pass, the polarity of the electrode 33 may be changed for each pass, or the polarity of the electrode 33 may be changed for every two passes. Good. Further, when the polarity of the electrode 33 becomes both positive and negative within a predetermined time, the time when the polarity of the electrode 33 is positive and the time when the polarity of the electrode 33 is negative may be different. .. That is, the ratio of the time when the polarity of the electrode 33 is positive and the ratio of the time when the polarity of the electrode 33 is negative may be different from the predetermined time. For example, out of the time for 3 passes, the time when the polarity of the electrode 33 is positive may be 1 pass, and the time when the polarity of the electrode 33 is negative may be 2 passes. The time when the polarity of the electrode 33 is positive may be longer than the time when the polarity of the electrode 33 is negative, and the time when the polarity of the electrode 33 is negative is the time when the polarity of the electrode 33 is positive. May be longer than.

In the present embodiment, the control unit 35 determines whether the media 99 is likely to be charged, positive or negative, and changes the polarity of the electrode 33 according to the determination, but the control unit 35 responds to the determination. The time when the polarity of the electrode 33 is positive and the time when the polarity of the electrode 33 is negative may be changed. For example, the control unit 35 may determine whether the media 99 is likely to be charged, positive or negative, based on the media type information. As a control of the polarity of the electrode 33, the control unit 35 tends to positively charge the media 99 for a period of time when the polarity of the electrode 33 is positive when it is determined that the media 99 is likely to be negatively charged within a predetermined time. It may be longer than the time when the polarity of the electrode 33 is positive when it is determined that.

When the media 99 is likely to be negatively charged, the foreign matter generated from the media 99 is likely to be negatively charged. Therefore, if the time during which the polarity of the electrode 33 is positive is lengthened, the foreign matter generated from the media 99 can be effectively collected. When the media 99 is likely to be positively charged, the foreign matter generated from the media 99 is likely to be positively charged, so that the time during which the polarity of the electrode 33 is positive may be shortened. Therefore, when the control unit 35 determines that the media 99 is likely to be negatively charged, the time during which the polarity of the electrode 33 is positive is determined by the control unit 35 when the media 99 is likely to be positively charged. By making the polarity of the electrode 33 longer than the time when the polarity is positive, foreign matter in the housing 12 can be effectively collected. The control unit 35 controls the media type information and the media 99 occupying the foreign matter existing in the housing 12 to change the time when the polarity of the electrode 33 is positive and the time when the polarity of the electrode 33 is negative. It may be performed based on a parameter relating to the proportion of foreign matter generated from, that is, the amount of blown air by the blowing mechanism 37, the amount of foreign matter measured by the measuring instrument 41, and at least one of the humidity of the atmosphere. In this case, when the parameter indicates that the ratio of the foreign matter generated from the media 99 to the foreign matter existing in the housing 12 is large, the control unit 35 tells the media 99 to the foreign matter existing in the housing 12. By lengthening the time during which the polarity of the electrode 33 corresponds to the media type information, the foreign matter in the housing 12 can be collected more effectively than in the case of indicating that the proportion of foreign matter generated from the medium is small. ..

As shown in FIG. 2, the printing apparatus 11 may include a collection unit 47 that collects foreign matter collected by the electrode 33. The recovery unit 47 is located, for example, at a position directly below the electrode 33 when the holding unit 31 is located at the home position. The home position is a position where the holding unit 31 stands by. When printing on the media 99 is started, the holding unit 31 moves from the home position.

When the collection unit 47 collects the foreign matter collected by the electrode 33, the control unit 35 may turn off the power of the electrode 33 or change the polarity of the electrode 33. When the power of the electrode 33 is turned off, the Coulomb force between the electrode 33 and the foreign matter disappears, so that the foreign matter is easily separated from the electrode 33. When the polarity of the electrode 33 is changed, the polarity is opposite to the polarity of the collected foreign matter, so that the foreign matter can be easily separated from the electrode 33. In the present embodiment, the foreign matter falls from the electrode 33 when it separates from the electrode 33. The collecting unit 47 collects the foreign matter by receiving the foreign matter falling from the electrode 33. The recovery unit 47 may recover the foreign matter by wiping the electrode 33, or may recover the foreign matter by blowing gas onto the electrode 33.

The polarity of the electrode 33 may be controlled by a machine learning unit that performs machine learning. In this case, the control unit 35 may function as a machine learning unit. For example, the control unit 35 observes a state variable including at least the media type information, acquires the nozzle dropout data related to the occurrence of nozzle dropout after the electrode 33 is controlled based on the media type information, and obtains the state. According to the training data set created based on the combination of variables, electrode control, and nozzle dropout data, the conditions associated with the occurrence of nozzle dropout after control of the electrode 33 is learned, and this The electrode 33 may be controlled based on the conditions. By doing so, the polarity of the electrode 33 can be controlled more appropriately, so that foreign matter can be effectively collected.

As shown in FIG. 3, the control unit 35 that functions as a machine learning unit includes a state observation unit 51, a nozzle omission data acquisition unit 52, and a learning unit 53. The state observation unit 51 observes a state variable including at least media type information. The state variable may include the measured value of the measuring device 41, the temperature outside the housing 12 detected by the detector 42, and the like. The state variables may also include the amount of liquid discharged by the head 28 to the media 99, the transport speed of the media 99 by the transport unit 14, and the like. The state observation unit 51 observes such a state variable.

The nozzle omission data acquisition unit 52 acquires the nozzle omission data related to the occurrence of the nozzle omission of the nozzle 29 that cannot normally discharge the liquid. The nozzle omission data is data obtained by, for example, performing a nozzle inspection.

The control unit 35 performs a nozzle inspection by detecting, for example, a vibration state in the liquid chamber communicating with the nozzle 29. The head 28 has an actuator that applies pressure to the liquid chamber. The liquid is discharged from the nozzle 29 by the actuator applying pressure to the liquid chamber. When the actuator applies pressure to the liquid chamber, the liquid chamber vibrates. When the liquid in the nozzle 29 is thickened, the period of vibration in the liquid chamber communicating with the nozzle 29 tends to be long. When air bubbles are mixed in the liquid chamber communicating with the nozzle 29, the period of vibration in the liquid chamber communicating with the nozzle 29 tends to be shortened. In this way, the nozzle omission of the nozzle 29 can be detected.

As a method of detecting nozzle omission, for example, the meniscus in the nozzle 29 is irradiated with light from a light emitting element, the reflected light is received by the light receiving element to detect the vibration state of the meniscus, and the nozzle is detected from the detected vibration state. There is a method of inspecting the discharge state of 29. There is a method of inspecting the discharge state of the nozzle 29 by using a general optical sensor that detects whether or not the liquid discharged from the nozzle 29 is within the detection range of the sensor. There is a method of inspecting the discharge state of the nozzle 29 by using a heat-sensitive sensor that detects a temperature change of a heat-sensing unit that receives the discharged liquid. There is a method of ejecting a charged liquid from a nozzle 29 and inspecting the ejection state of the nozzle 29 by using a sensor that detects a change in the amount of charge of a detection electrode on which the liquid has landed. There is a method of inspecting the discharge state of the nozzle 29 by using a capacitance type sensor that changes as the discharged liquid passes between the electrodes. There is a method of inspecting the ejection state of the nozzle 29 by detecting the inspection pattern formed by ejecting the liquid from the nozzle 29 onto the media 99 or the like as image information by a sensor such as a camera.

The learning unit 53 follows a training data set created based on the combination of the state variables observed by the state observation unit 51, the control of the electrodes 33, and the nozzle omission data acquired by the nozzle omission data acquisition unit 52. , Learn the conditions associated with the occurrence of nozzle omission after the control of the electrode 33 is performed. Any learning algorithm may be used as the learning algorithm used by the learning unit 53. Learning algorithms include, for example, supervised learning, unsupervised learning, and reinforcement learning. The control unit 35 controls the electrode 33 based on the learned conditions.

Next, the action and effect of the above embodiment will be described.
(1) The control unit 35 changes the polarity of the electrode 33 between positive and negative. When the head 28 is positively charged, the control unit 35 makes the potential of the electrode 33 when the polarity of the electrode 33 is positive larger than the potential of the head 28. When the head 28 is negatively charged, the control unit 35 makes the potential of the electrode 33 when the polarity of the electrode 33 is negative larger than the potential of the head 28. As a result, when the polarity of the electrode 33 is positive, negatively charged foreign matter can be collected. When the polarity of the electrode 33 is negative, positively charged foreign matter can be collected. That is, both negatively charged foreign matter and positively charged foreign matter can be collected.

(2) The electrode 33 is provided on the side surface 31A of the holding portion 31 in the scanning direction. In this way, for example, the electrode 33 is arranged at a position distant from the head 28 as compared with the case where the electrode 33 is provided on the bottom surface of the holding portion 31. Therefore, it is possible to reduce the possibility that foreign matter collected by the electrode 33 approaches the head 28. This makes it possible to reduce the possibility of foreign matter adhering to the head 28.

(3) When the collecting unit 47 collects the foreign matter collected by the electrode 33, the control unit 35 turns off the power of the electrode 33 or changes the polarity of the electrode 33. When the power of the electrode 33 is turned off, the Coulomb force between the electrode 33 and the foreign matter disappears, so that the foreign matter is easily separated from the electrode 33. When the polarity of the electrode 33 is changed, the polarity is opposite to the polarity of the collected foreign matter, so that the foreign matter can be easily separated from the electrode 33. That is, according to the above embodiment, the collecting unit 47 can easily collect the foreign matter collected by the electrode 33.

(4) The control unit 35 controls the polarity of the electrode 33 based on the media type information indicating the information of the media 99. Based on the media type information, it is possible to determine whether the media 99 is likely to be charged, positive or negative. Therefore, according to the above embodiment, foreign matter generated from the media 99 can be effectively collected.

(5) When the control unit 35 determines whether the media 99 is likely to be charged positively or negatively based on the media type information, and determines that the media 99 is likely to be positively charged as a control of the polarity of the electrode 33. , The polarity of the electrode 33 is changed to negative, and when it is determined that the media 99 is likely to be negatively charged, the polarity of the electrode 33 is changed to positive. According to the above embodiment, since the polarity of the electrode 33 is controlled so as to have the polarity opposite to the polarity of the charged media 99, foreign matter generated from the media 99 can be effectively collected.

(6) The control unit 35 determines that the polarity of the electrode 33 is positive when the media 99 is likely to be negatively charged, and the polarity of the electrode 33 when the media 99 is determined to be positively charged. Make it longer than the positive time. When it is determined that the media 99 is likely to be negatively charged, the foreign matter generated from the media 99 is likely to be negatively charged. Therefore, if the time during which the polarity of the electrode 33 is positive is lengthened, the foreign matter generated from the media 99 is effectively collected. it can. When it is determined that the media 99 is likely to be positively charged, the foreign matter generated from the media 99 is likely to be positively charged, so that the time during which the polarity of the electrode 33 is positive may be shortened. Therefore, the time when the polarity of the electrode 33 is positive when it is determined that the media 99 is likely to be negatively charged is larger than the time when the polarity of the electrode 33 is positive when it is determined that the media 99 is likely to be positively charged. By lengthening it, foreign matter can be effectively collected.

(7) The control unit 35 acquires the media type information from the server. In the server, the media type information is updated as appropriate. Therefore, according to the above embodiment, the media type information can be appropriately acquired. Thereby, the polarity of the electrode 33 can be controlled based on the latest media type information.

(8) The control unit 35 controls the polarity of the electrode 33 based on the amount of air blown by the air blowing mechanism 37 and the media type information. When the blowing mechanism 37 sends the atmosphere from the outside of the housing 12 into the housing 12, foreign substances in the atmosphere enter the housing 12 together with the atmosphere. Therefore, if the amount of air blown by the air blowing mechanism 37 is large, the amount of foreign matter entering the housing 12 increases. When the amount of air blown by the air blowing mechanism 37 is small, the amount of foreign matter sent into the housing 12 is small. Therefore, by controlling the polarity of the electrode 33 based on the amount of air blown by the air blowing mechanism 37 and the media type information, foreign matter in the housing 12 can be effectively collected.

(9) The control unit 35 controls the polarity of the electrode 33 based on the amount of foreign matter measured by the measuring instrument 41 and the media type information. By controlling the polarity of the electrode 33 based on the amount of foreign matter sent into the housing 12 and the media type information, the foreign matter in the housing 12 can be effectively collected.

(10) The control unit 35 controls the output of the preheater 43 based on the humidity detected by the detector 42, and controls the polarity of the electrode 33 based on the humidity detected by the detector 42 and the media type information. .. When the humidity of the atmosphere is high, it becomes difficult for foreign matter in the atmosphere to enter the housing 12, so that the proportion of foreign matter existing in the housing 12 due to the media 99 increases. Therefore, for example, when the humidity is high, foreign matter in the housing 12 is effectively captured by controlling the electrode 33 so that the polarity is opposite to the polarity of the media 99 that is easily charged based on the media type information. Can be collected.

(11) The control unit 35 observes a state variable including at least media type information, acquires nozzle omission data related to the occurrence of nozzle omission after the electrode 33 is controlled based on the media type information, and obtains nozzle omission data. According to the training data set created based on the combination of the state variable, the control of the electrode 33, and the nozzle dropout data, the conditions associated with the occurrence of nozzle dropout after the control of the electrode 33 is learned. The electrode 33 is controlled based on the conditions. According to this, the polarity of the electrode 33 can be appropriately controlled.

This embodiment can be modified and implemented as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
-Two or more electrodes 33 may be provided.

The electrode 33 may be provided on the side surface on the upstream side of the holding portion 31 in the transport direction D1, or may be provided on the side surface on the downstream side of the holding portion 31 in the transport direction D1. The electrode 33 may be provided on the side surface of the holding portion 31 opposite to the side surface 31A, or may be provided on the upper surface of the holding portion 31.

-The preheater 43 may be composed of a heater tube.
The after heater 44 may be composed of a sheet-shaped heater.
The media 99 is not limited to the long paper unwound from the roll body 100, and may be a single sheet of paper. The media 99 is not limited to paper, but may be cloth.

The liquid discharged by the head 28 is not limited to ink, and may be, for example, a liquid material in which particles of a functional material are dispersed or mixed in the liquid. For example, the head 28 may discharge a liquid material containing a material such as an electrode material or a pixel material used for manufacturing a liquid crystal display, an electroluminescence display, a surface emitting display, or the like in a dispersed or dissolved form.

The technical idea and its action and effect grasped from the above-described embodiment and modification are described below.
The printing device includes a head for printing on media, a holding portion for holding the head, an electrode provided on the holding portion for collecting foreign matter, and a control unit for changing the polarity of the electrode between positive and negative. When the head is positively charged, the control unit increases the potential of the electrode when the polarity of the electrode is positive to be larger than the potential of the head, and the head is negatively charged. , The potential of the electrode when the polarity of the electrode is negative is made larger than the potential of the head.

According to the above configuration, when the polarity of the electrode is positive, negatively charged foreign matter can be collected. When the polarity of the electrode is negative, positively charged foreign matter can be collected. That is, both negatively charged foreign matter and positively charged foreign matter can be collected.

In the printing apparatus, the head is located on the bottom surface of the holding portion, the holding portion can scan the media, and the electrodes may be provided on the side surface of the holding portion in the scanning direction. Good.

According to the above configuration, the electrodes are arranged at positions away from the head, as compared with the case where the electrodes are provided on the bottom surface of the holding portion, for example. Therefore, it is possible to reduce the possibility that foreign matter collected by the electrodes approaches the head. This makes it possible to reduce the risk of foreign matter adhering to the head.

The printing device includes a collection unit that collects foreign matter collected by the electrode, and the control unit turns off the power of the electrode when the collection unit collects the foreign matter collected by the electrode. , The polarity of the electrode may be changed.

When the electrode is de-energized, the Coulomb force between the electrode and the foreign matter disappears, so that the foreign matter easily separates from the electrode. When the polarity of the electrode is changed, the polarity is opposite to the polarity of the collected foreign matter, so that the foreign matter can be easily separated from the electrode. According to the above configuration, the collecting unit can easily collect the foreign matter collected by the electrodes.

In the printing apparatus, the control unit may control the polarity of the electrodes based on the media type information indicating the information of the media.
Based on the media type information, it is possible to determine whether the media is likely to be charged, positive or negative. Therefore, according to the above configuration, foreign matter generated from the media can be effectively collected.

In the printing apparatus, the control unit determines whether the media is likely to be charged positively or negatively based on the media type information, and the control unit positively controls the polarity of the electrodes. When it is determined that the media is easily charged, the polarity of the electrode may be changed to negative, and when it is determined that the media is likely to be negatively charged, the polarity of the electrode may be changed to positive.

According to the above configuration, since the polarity of the electrode is controlled so as to have the polarity opposite to the polarity of the charged medium, foreign matter generated from the medium can be effectively collected.
In the printing apparatus, the control unit determines whether the media is likely to be charged, positive or negative, based on the media type information, and the control unit controls the polarity of the electrode, and the control unit controls the polarity of the electrode. The time when the polarity of the electrode is positive when it is determined that the media is likely to be negatively charged is the time when the control unit determines that the media is likely to be positively charged, and the polarity of the electrode is positive. It may be longer than a certain time.

When it is determined that the media is likely to be negatively charged, the foreign matter generated from the media is likely to be negatively charged. Therefore, if the time during which the polarity of the electrode is positive is lengthened, the foreign matter generated from the media can be effectively collected. When it is determined that the media is likely to be positively charged, the foreign matter generated from the media is likely to be positively charged, so that the time during which the polarity of the electrode is positive may be shortened. Therefore, by making the time when the polarity of the electrode is positive when it is determined that the media is likely to be negatively charged longer than the time when the polarity of the electrode is positive when it is determined that the media is likely to be positively charged. , Foreign matter can be collected effectively.

In the printing device, the control unit may acquire the media type information from the server.
According to the above configuration, media type information can be appropriately acquired.

The printing device includes a housing for accommodating the head and a blowing mechanism for blowing air from outside the housing into the housing, and the control unit uses the blowing amount by the blowing mechanism and the media type information. Based on this, the polarity of the electrode may be controlled.

When the blower mechanism sends the atmosphere into the housing from the outside of the housing, foreign substances in the atmosphere enter the housing together with the atmosphere. Therefore, if the amount of air blown by the air blowing mechanism is large, the amount of foreign matter entering the housing increases. If the amount of air blown by the air blowing mechanism is small, the amount of foreign matter sent into the housing is small. Therefore, by controlling the polarity of the electrode based on the amount of air blown by the air blowing mechanism and the media type information, foreign matter in the housing can be effectively collected.

The printing device has a housing for accommodating the head, a flow path communicating with the outside of the housing and the inside of the housing, and a blowing mechanism for sending air from the outside of the housing to the inside of the housing through the flow path, and the above. A measuring instrument located in the flow path and measuring the amount of foreign matter sent into the housing by the blowing mechanism is provided, and the control unit uses the amount of foreign matter measured by the measuring instrument and the media type information. Based on this, the polarity of the electrode may be controlled.

According to the above configuration, by controlling the polarity of the electrode based on the amount of foreign matter sent into the housing and the media type information, the foreign matter in the housing can be effectively collected.
The printing device has a housing for accommodating the head, a flow path communicating with the outside of the housing and the inside of the housing, and a blowing mechanism for sending air from the outside of the housing to the inside of the housing through the flow path, and the above. A detector for detecting the humidity outside the housing and a preheater for heating the media before printing are provided, and the control unit controls the output of the preheater based on the humidity detected by the detector. The polarity of the electrode may be controlled based on the humidity detected by the detector and the media type information.

When the humidity of the atmosphere is high, it becomes difficult for foreign substances in the atmosphere to enter the housing, so that the proportion of foreign substances existing in the housing increases due to the media. Therefore, for example, when the humidity is high, foreign matter in the housing can be effectively collected by controlling the electrodes so that the polarity is opposite to the polarity in which the media is easily charged based on the media type information.

In the printing apparatus, the control unit observes a state variable including at least the media type information, and nozzle omission data related to the occurrence of nozzle omission after the electrodes are controlled based on the media type information. Is associated with the occurrence of nozzle dropout after control of the electrode according to a training data set created based on the combination of the state variable, control of the electrode, and nozzle dropout data. The electrode may be controlled based on the condition to be learned.

According to the above configuration, the polarity of the electrode can be appropriately controlled.

11 ... Printing device, 12 ... Housing, 13 ... Base, 14 ... Transport section, 15 ... Transport path, 16 ... Mounting section, 17 ... Winding section, 18 ... Tension applying member, 21 ... First support section, 22 ... 2nd support, 23 ... 3rd support, 25 ... 1st roller, 26 ... 2nd roller, 28 ... head, 29 ... nozzle, 31 ... holding part, 31A ... side surface, 32 ... guide shaft, 33 ... Electrodes, 35 ... Control unit, 37 ... Blower mechanism, 38 ... Flow path, 39 ... Fan, 41 ... Measuring instrument, 42 ... Detector, 43 ... Preheater, 44 ... After heater, 45 ... Heater tube, 47 ... Recovery unit , 51 ... State observation unit, 52 ... Nozzle missing data acquisition unit, 53 ... Learning unit, 99 ... Media, 100 ... Roll body, D1 ... Transport direction.

Claims (11)

The head that prints on the media and
A holding portion that holds the head and
An electrode provided on the holding portion for collecting foreign matter, and
A control unit that changes the polarity of the electrode between positive and negative is provided.
When the head is positively charged, the control unit increases the potential of the electrode when the polarity of the electrode is positive to be larger than the potential of the head.
A printing apparatus characterized in that when the head is negatively charged, the potential of the electrode when the polarity of the electrode is negative is made larger than the potential of the head. The head is located on the bottom surface of the holding portion.
The holding portion is scannable with respect to the media and
The printing apparatus according to claim 1, wherein the electrode is provided on a side surface of the holding portion in the scanning direction. A collection unit for collecting foreign matter collected by the electrode is provided.
The first or second aspect of the control unit is characterized in that, when the collection unit collects the foreign matter collected by the electrode, the electrode is turned off or the polarity of the electrode is changed. The printing apparatus described in. The printing apparatus according to any one of claims 1 to 3, wherein the control unit controls the polarity of the electrode based on the media type information indicating the information of the media. The control unit determines whether the media is likely to be charged, positive or negative, based on the media type information.
The control unit controls the polarity of the electrode.
When it is determined that the media is likely to be positively charged, the polarity of the electrode is changed to negative.
The printing apparatus according to claim 4, wherein the polarity of the electrode is changed to positive when it is determined that the medium is likely to be negatively charged. The control unit determines whether the media is likely to be charged, positive or negative, based on the media type information.
The control unit controls the polarity of the electrode, and the control unit determines that the media is likely to be negatively charged for a period of time during which the polarity of the electrode is positive. The printing apparatus according to claim 4, wherein the polarity of the electrode is longer than the time when it is determined that the electrode is positively charged. The printing apparatus according to any one of claims 4 to 6, wherein the control unit acquires the media type information from a server. A housing for accommodating the head and
A ventilation mechanism that sends air from outside the housing to the inside of the housing is provided.
The printing apparatus according to any one of claims 4 to 7, wherein the control unit controls the polarity of the electrode based on the amount of air blown by the blowing mechanism and the media type information. .. A housing for accommodating the head and
A blower mechanism having a flow path leading to the outside of the housing and the inside of the housing and sending air from the outside of the housing to the inside of the housing through the flow path.
A measuring instrument located in the flow path and measuring the amount of foreign matter sent into the housing by the ventilation mechanism is provided.
The control unit according to any one of claims 4 to 7, wherein the control unit controls the polarity of the electrode based on the amount of foreign matter measured by the measuring instrument and the media type information. Printing equipment. A housing for accommodating the head and
A blower mechanism having a flow path leading to the outside of the housing and the inside of the housing and sending air from the outside of the housing to the inside of the housing through the flow path.
A detector that detects the humidity outside the housing and
A preheater that heats the media before printing is provided.
The control unit controls the output of the preheater based on the humidity detected by the detector.
The printing apparatus according to any one of claims 4 to 7, wherein the polarity of the electrode is controlled based on the humidity detected by the detector and the media type information. The control unit
Observe at least the state variables containing the media type information and
After the electrode is controlled based on the media type information, the nozzle omission data related to the occurrence of nozzle omission is acquired.
According to the training data set created based on the combination of the state variable, the electrode control, and the nozzle dropout data, the conditions associated with the occurrence of nozzle dropout after the electrode control is performed are learned. And
The printing apparatus according to any one of claims 4 to 10, wherein the electrodes are controlled based on the conditions.