JP2020163823A - Ink jet printer and computer program for cleaning - Google Patents

Abstract

To provide an ink jet printer in which ink in a cap does not easily enter nozzles of an ink head and ink in the cap does not easily spatter.SOLUTION: A printer 100 includes an ink head 41 including a nozzle surface 45 including nozzles 51 and 52, a cap 111 including an end part 118 contactable with the nozzle surface 45, a suction device 131, a memory device 150, and a control device 160. The memory device 150 stores a suction position P51, a free suction position P52, and a minute open position P53 located between the suction position P51 and the free suction position 52. The control device 160 is configured to perform suction processing in which the cap 111 is located at the suction position P51 and ink is sucked from the nozzles 51 and 52, and minute open position processing in which the cap 111 is moved toward the minute open position P53 and movement of the cap 111 is stopped while the cap 111 is located at the minute open position P53, after the suction processing.SELECTED DRAWING: Figure 15

Description

The present invention relates to an inkjet printer and a computer program for cleaning.

For example, Patent Document 1 discloses an inkjet printer including an ink head having a nozzle for ejecting ink. In the above-mentioned inkjet printer, a cap unit is provided in order to maintain the ejection performance of the nozzle. The cap unit includes a cap mounted on the nozzle surface on which the nozzle of the ink head is formed during standby for printing, and a suction pump connected to the cap.

By attaching the cap to the nozzle surface, a closed space is formed between the nozzle surface and the cap. By driving the suction pump in the state where this closed space is formed, the ink remaining in the ink head can be discharged to the cap. The suction process for ejecting the ink in the ink head in this way is called a suction process.

Further, after the suction treatment, in order to discharge the ink remaining in the cap, the nozzle surface and the cap are separated from each other, and the suction pump is driven again with the closed space open to atmospheric pressure. There is. As a result, the ink in the cap can be discharged without applying an excessive negative pressure to the ink head. The suction process for ejecting the ink in the cap is called an air suction process.

Japanese Unexamined Patent Publication No. 2016-87858

By the way, in the above-mentioned inkjet printer, a negative pressure adjustment process may be performed after the suction process. The negative pressure adjustment process is a process of stopping the suction pump for a predetermined time with the cap attached to the nozzle surface. The ink in the cap may contain dust and the like adhering to the nozzle surface. Therefore, the longer the negative pressure adjustment process is performed, the more the ink in the cap, which is a mixture of dust and the like, may flow back into the nozzle. Further, before executing the air suction process, the cap is removed from the nozzle surface so that the nozzle surface and the cap are separated from each other. When the cap is removed in this way, a pressure difference is generated between the inside of the cap and the outside of the cap, so that the ink in the cap may scatter.

The present invention has been made in view of this point, and an object of the present invention is to provide an inkjet printer and a computer program for cleaning in which the ink in the cap does not easily enter the nozzle of the ink head and the ink in the cap does not easily scatter. Is to provide.

The inkjet printer according to the present invention includes an ink head, a cap unit, a storage device, and a control device. The ink head has a nozzle surface provided with a nozzle for ejecting ink. The cap unit has a cap, a suction device, and a capping mechanism. The cap can be attached to the nozzle surface so as to cover the nozzle surface, and has an end portion that can come into contact with the nozzle surface when attached to the nozzle surface. The suction device is connected to the cap. The capping mechanism attaches or separates the cap from the nozzle surface. The storage device stores the suction position, the empty suction position, and the minute open position in advance. The suction position is the position of the cap when the end portion of the cap is in contact with the nozzle surface and the ink in the nozzle is sucked by the suction device. The air suction position is the position of the cap when the end portion of the cap is separated from the nozzle surface and the ink in the nozzle is not sucked by the suction device. The micro open position is located between the suction position and the empty suction position. The control device is configured to perform suction processing, movement processing, and minute open position processing. In the suction process, ink is sucked from the nozzle with the cap arranged at the suction position. In the movement process, after the suction process, the cap is moved toward the minute open position. In the micro open position process, after the move process, the movement of the cap is stopped with the cap placed at the micro open position.

Another inkjet printer according to the present invention includes an ink head, a cap unit, a storage device, and a control device. The ink head has a nozzle surface provided with a nozzle for ejecting ink. The cap unit has a cap, a suction device, and a capping mechanism. The cap can be attached to the nozzle surface so as to cover the nozzle surface, and has an end portion that can come into contact with the nozzle surface when attached to the nozzle surface. The suction device is connected to the cap. The capping mechanism attaches or separates the cap from the nozzle surface. The storage device stores the suction position, the empty suction position, and the minute open position in advance. The suction position is the position of the cap when the end portion of the cap is in contact with the nozzle surface and the ink in the nozzle is sucked by the suction device. The air suction position is the position of the cap when the end portion of the cap is separated from the nozzle surface and the ink in the nozzle is not sucked by the suction device. The micro open position is located between the suction position and the empty suction position. The control device is configured to perform suction processing, movement processing, and minute open position processing. In the suction process, ink is sucked from the nozzle with the cap arranged at the suction position. In the movement process, after the suction process, the cap is moved toward the minute open position. In the micro open position processing, after the movement process, the movement of the cap is stopped and the suction device is stopped in a state where the cap is arranged at the micro open position.

According to each of the above-mentioned inkjet printers, after the suction process, the negative pressure adjustment process as described above is not executed, and the minute open position process is executed. When the suction device is driven during the suction process, the inside of the cap becomes negative pressure. With the inside of the cap under negative pressure, the cap moves to the minute open position by the movement process, and the minute open position process is executed. Immediately after the micro open position processing is executed, the ink inside the cap is sucked because the pressure inside the cap is negative. As described above, in each of the above-mentioned inkjet printers, the minute open position process in which the ink in the cap is sucked is executed without executing the negative pressure adjustment process. Therefore, since the time required for the negative pressure adjustment process can be shortened, the time at which the ink in the cap may enter the nozzle can be shortened. Therefore, it is possible to prevent the ink in the cap from entering the nozzle. Further, according to each of the above-mentioned inkjet printers, the micro open position, which is the position of the cap during the micro open position processing, is a position where the end of the cap is closer to the nozzle surface than the air suction position. .. Therefore, since the gap between the nozzle surface and the cap can be made relatively small, it is possible to prevent the ink in the cap from scattering to the outside.

According to the present invention, it is possible to provide an inkjet printer and a computer program for cleaning in which the ink in the cap is hard to enter into the nozzle of the ink head and the ink in the cap is hard to scatter.

It is a front view of the inkjet printer which concerns on embodiment. It is a figure which shows typically the structure of the lower surface of a carriage. It is a conceptual diagram which shows the relationship between an ink head and an ink supply system. It is a schematic diagram which shows the structure of two ink supply systems which concern on 1st ink head. It is a top view of the damper, and is the figure which shows the state which the pressure of a storage chamber is equal to or less than a predetermined determination pressure. It is a plan sectional view of a damper, and is the figure which shows the state which the pressure of a storage chamber is larger than a predetermined determination pressure. It is a front view of the ink head and a cap unit. It is a front view of the ink head and a cap unit. It is a front view which shows the positional relationship between a cap and a nozzle surface, and is the figure which shows the air suction position. It is a front view which shows the positional relationship between a cap and a nozzle surface, and is the figure which shows the minute opening position. It is a front view which shows the positional relationship between a cap and a nozzle surface, and is the figure which shows the suction position. It is a front view of an ink head and a wiper unit. It is a block diagram of an inkjet printer. It is a flowchart which showed the procedure of determining an air suction position. It is a flowchart which showed the procedure of determining an air suction position. It is a flowchart which showed the cleaning procedure. The position of the cap in each cleaning process, the contact between the end of the cap and the absorber and the nozzle surface, the pressure in the cap, the drive of the suction pump, and the amount of movement of the cap per unit time in the first and second movement processes. It is a figure which showed about. It is a front view which shows the cap which concerns on other embodiment, and is the figure corresponding to FIG.

Hereinafter, embodiments of the inkjet printer according to the present invention will be described with reference to the drawings. It should be noted that the embodiments described here are, of course, not intended to particularly limit the present invention. In addition, members and parts that perform the same action are designated by the same reference numerals, and duplicate explanations are omitted or simplified as appropriate.

FIG. 1 is a front view of an inkjet printer (hereinafter referred to as a printer) 100 according to the present embodiment. In the following description, the reference numerals F, Rr, L, R, U, and D in the drawings mean front, rear, left, right, top, and bottom when the printer 100 is viewed from the front. Reference numeral Y in the drawings indicates the main scanning direction. In the present embodiment, the main scanning direction Y is the left-right direction. The main scanning direction Y is the moving direction of the ink heads 41 to 44, which will be described later. Reference numeral X in the drawing indicates a sub-scanning direction. In the present embodiment, the sub-scanning direction X is the front-back direction, which is orthogonal to the main scanning direction Y in a plan view. The sub-scanning direction X is the transport direction of the medium 5, which will be described later. However, the above direction is merely a direction determined for convenience of explanation, and does not limit the installation mode of the printer 100 at all, nor does it limit the present invention at all.

The printer 100 is an inkjet printer. The printer 100 prints on the medium 5. The medium 5 is, for example, a roll-shaped recording paper. However, the medium 5 is not limited to the roll-shaped recording paper, and may be a sheet-shaped recording paper, such as a resin sheet or film such as polyvinyl chloride or polyester, a plate material, a woven fabric, or a non-woven fabric. It may be a cloth or other medium.

As shown in FIG. 1, the printer 100 includes a printer main body 11, a platen 13, a transport mechanism 20, a guide rail 15, a carriage 17, a head moving mechanism 30, and ink heads 41 to 44 (see FIG. 2). The ink supply system 61 to 68 (see FIG. 3), the cleaning system 90 (see FIG. 7), the storage device 150, and the control device 160 are provided.

The printer main body 11 has a casing extending in the main scanning direction Y. The platen 13 supports the medium 5. The medium 5 is placed on the platen 13. Printing is performed on the platen 13. The platen 13 extends in the main scanning direction Y.

The medium 5 supported by the platen 13 is conveyed in the sub-scanning direction X by the conveying mechanism 20. The configuration of the transport mechanism 20 is not particularly limited. In the present embodiment, the transport mechanism 20 includes a pinch roller 21, a grit roller 22, and a feed motor 23. The pinch roller 21 is provided above the platen 13 and behind the carriage 17, and presses the medium 5 from above. The grit roller 22 is a cylindrical member provided on the platen 13. Here, the grit roller 22 is embedded in the platen 13 with its upper surface exposed. The grit roller 22 faces the pinch roller 21. Here, the feed motor 23 is connected to the grit roller 22. When the feed motor 23 is driven with the medium 5 sandwiched between the pinch roller 21 and the grit roller 22, the grit roller 22 rotates. As a result, the medium 5 is conveyed in the sub-scanning direction X.

The guide rail 15 is arranged above the platen 13. The guide rail 15 is arranged parallel to the platen 13 and extends in the main scanning direction Y. A carriage 17 is engaged with the guide rail 15. The carriage 17 is slidably provided on the guide rail 15.

The head moving mechanism 30 is a mechanism for moving the carriage 17 and the ink heads 41 to 44 (see FIG. 2) in the main scanning direction Y. The configuration of the head moving mechanism 30 is not particularly limited. In the present embodiment, the head moving mechanism 30 includes left and right pulleys 31a and 31b, a belt 32, and a carriage motor 33. The left pulley 31a is provided at the left end of the guide rail 15. The right pulley 31b is provided at the right end of the guide rail 15. The belt 32 is an endless belt and is wound around the left and right pulleys 31a and 31b. A carriage 17 is attached to the belt 32. Here, the carriage motor 33 is connected to the right pulley 31b. By driving the carriage motor 33, the right pulley 31b rotates and the belt 32 travels. As a result, the carriage 17 and the ink heads 41 to 44 move along the guide rail 15 in the main scanning direction Y.

FIG. 2 is a diagram schematically showing the configuration of the lower surface of the carriage 17. As shown in FIG. 2, the ink heads 41 to 44 are provided on the carriage 17. The ink heads 41 to 44 are held by the carriage 17 so as to expose the lower surface thereof. In the following description, the ink heads 41 to 44 may be appropriately referred to as the first to fourth ink heads 41 to 44, respectively. The ink heads 41 to 44 eject ink. The ink heads 41 to 44 are arranged side by side in the main scanning direction Y. In the present embodiment, for example, the first ink head 41 is an example of the ink head of the present invention.

The ink heads 41 to 44 each have a nozzle surface 45. The nozzle surface 45 is formed on the lower surface of the ink heads 41 to 44, respectively. On the nozzle surface 45 of the first ink head 41, a plurality of nozzles 51 are formed side by side in the sub-scanning direction X, and a plurality of nozzles 52 are formed side by side in the sub-scanning direction X. Similarly, on the nozzle surface 45 of the second ink head 42, a plurality of nozzles 53 are formed side by side in the sub-scanning direction X, and a plurality of nozzles 54 are formed side by side in the sub-scanning direction X. On the nozzle surface 45 of the third ink head 43, a plurality of nozzles 55 are formed side by side in the sub-scanning direction X, and a plurality of nozzles 56 are formed side by side in the sub-scanning direction X. Further, on the nozzle surface 45 of the fourth ink head 44, a plurality of nozzles 57 are formed side by side in the sub-scanning direction X, and a plurality of nozzles 58 are formed side by side in the sub-scanning direction X. Here, the plurality of rows of nozzles 51 to 58 are referred to as nozzle rows 51a to 58a, respectively. The ink heads 41 to 44 each have two nozzle rows. In the present embodiment, for example, the nozzle 51 corresponds to the nozzle of the present invention, and the nozzle 52 corresponds to the other nozzle of the present invention.

FIG. 3 is a conceptual diagram showing the relationship between the ink heads 41 to 44 and the ink supply systems 61 to 68. As shown in FIG. 3, the ink supply systems 61 to 68 are systems that supply ink to the ink heads 41 to 44. The ink supply systems 61 to 68 are provided for each nozzle row 51a to 58a. In this embodiment, since the number of nozzle rows is "8", the number of ink supply systems is also "8". Ink supply systems 61 to 68 are connected to the nozzles 51 to 58 constituting the nozzle rows 51a to 58a, respectively. Here, the ink supply systems 61 to 68 all have the same configuration. Therefore, in the following, the ink supply systems 61 and 62 related to the first ink head 41 will be described, and the description of the other ink supply systems 63 to 68 will be omitted or simplified. However, in the ink supply systems 61 to 68, the configuration of some ink supply systems 61 to 68 may be different from the configurations of other ink supply systems 61 to 68.

FIG. 4 is a schematic view showing the configurations of the ink supply systems 61 and 62 related to the first ink head 41. As shown in FIG. 4, the ink supply system 61 includes a first ink tank 71a, a first ink supply path 72a, a first liquid feed pump 73a, and a first damper 74a. The ink supply system 62 includes a second ink tank 71b, a second ink supply path 72b, a second liquid feed pump 73b, and a second damper 74b.

The first ink tank 71a is a container in which ink is stored. In the first ink tank 71a, for example, one of process color ink and special color ink (for example, white ink, clear ink, etc.) is stored. However, the color of the ink stored in the first ink tank 71a is not particularly limited. Further, the ink material is not limited in any way, and various materials conventionally used as ink materials for inkjet printers can be used. The ink may be, for example, a solvent-based (solvent-based) pigment ink or a water-based pigment ink. Alternatively, the ink may be a water-based dye ink, an ultraviolet curable pigment ink that is cured by receiving ultraviolet rays, or the like.

The first ink supply path 72a is a flow path connecting the first ink tank 71a and the first ink head 41. One end of the first ink supply path 72a is connected to the first ink head 41 via the first damper 74a. Specifically, one end of the first ink supply path 72a is connected to the nozzles 51 constituting the nozzle row 51a and communicates with the nozzles 51. The other end of the first ink supply path 72a is connected to the first ink tank 71a. The ink stored in the first ink tank 71a is ejected from the plurality of nozzles 51 constituting the first nozzle row 51a. The material of the first ink supply path 72a is not particularly limited. The first ink supply path 72a is composed of, for example, a flexible tube.

The first liquid feeding pump 73a is provided in the first ink supply path 72a. The first liquid feed pump 73a is a pump for supplying the ink stored in the first ink tank 71a to the nozzle 51 of the nozzle row 51a and adjusting the pressure to be suitable for ejecting the ink from the first ink head 41. Is. When the first liquid feeding pump 73a is driven, the first liquid feeding pump 73a feeds ink from the first ink tank 71a toward the nozzle 51 of the nozzle row 51a. The type of the first liquid feed pump 73a is not particularly limited, and examples thereof include a diaphragm pump and a tube pump.

The first damper 74a relaxes the pressure fluctuation of the ink and stabilizes the ink ejection operation of the first ink head 41. The first damper 74a detects the flow rate of the ink flowing into the first damper 74a (in other words, the pressure in the first damper 74a). Then, the first liquid feeding pump 73a is controlled based on the detection result of the ink flow rate. As shown in FIG. 4, the first damper 74a is connected to the first ink head 41. Here, the first damper 74a is provided above the first ink head 41. The configuration of the first damper 74a is not particularly limited.

FIG. 5 is a plan view of the dampers 74a and 74b, showing a state in which the pressure of the storage chamber 82 is equal to or lower than a predetermined determination pressure. FIG. 6 is a plan sectional view of the dampers 74a and 74b, showing a state in which the pressure of the storage chamber 82 is larger than the predetermined determination pressure. In the present embodiment, as shown in FIG. 5, the first damper 74a includes a damper main body 81, a storage chamber 82, a damper film 83, and a detection mechanism 84.

The damper body 81 is hollow. The storage chamber 82 is formed in the damper main body 81, and has an opening formed in a part thereof. Ink is temporarily stored in the storage chamber 82. The storage chamber 82 communicates with the first ink supply path 72a (see FIG. 4) and the first ink head 41 (see FIG. 4). In the present embodiment, an inflow port 85a to which the first ink supply path 72a is connected is formed in the upper part of the damper main body 81, and an outflow port 85b connected to the first ink head 41 is formed in the lower part of the damper main body 81. (See FIG. 4) is formed. However, the formation positions of the inflow port 85a and the outflow port 85b are not particularly limited. In the present embodiment, the first damper 74a is configured so that the ink flowing into the storage chamber 82 from the inflow port 85a at the time of printing flows to the first ink head 41 through the outflow port 85b.

As shown in FIG. 5, the damper film 83 is provided on the damper main body 81 so as to cover the opening portion of the storage chamber 82. Here, the space surrounded by the damper film 83 and the damper main body 81 is the storage chamber 82. The damper film 83 is made of, for example, a flexible resin film. As shown in FIGS. 5 and 6, the damper film 83 can be deformed to the inside and outside of the storage chamber 82 based on the amount of ink stored in the storage chamber 82 and the pressure in the storage chamber 82. The damper film 83 is attached to the damper main body 81 with a tension sufficient to bend the inside and outside of the storage chamber 82, respectively.

In the present embodiment, as shown in FIG. 5, the storage chamber 82 is provided with a spring 85. The spring 85 is arranged in the storage chamber 82 in a compressed state, and applies an elastic force toward the damper film 83. Here, the spring 85 is connected to the surface of the damper membrane 83 on the storage chamber 82 side. The type of the spring 85 is not particularly limited, and for example, the spring 85 is a coil spring.

The detection mechanism 84 is a mechanism for detecting the pressure in the storage chamber 82. Here, the detection mechanism 84 indirectly detects the pressure in the first ink supply path 72a (see FIG. 4) by detecting the pressure in the storage chamber 82. The configuration of the detection mechanism 84 is not particularly limited. In the present embodiment, the detection mechanism 84 includes a pressing body 86, a filler 87, and a filler sensor 88. The pressing body 86 is provided on the damper film 83. In the present embodiment, the pressing body 86 is provided on the surface of the damper film 83 on the storage chamber 82 side. The pressing body 86 is supported by the spring 85 and can move inside and outside the storage chamber 82 together with the bending of the damper film 83.

The filler 87 is provided on the damper body 81 so as to be in contact with the damper film 83 or the pressing body 86. In the present embodiment, the damper main body 81 is provided with the support spring 89, and the filler 87 is supported by the support spring 89. The shape of the filler 87 is not particularly limited. Here, the filler 87 is formed in a substantially U shape. Specifically, the filler 87 is provided on the right side of the pressing body 86 with a contact portion 87a extending in the front-rear direction, a support portion 87b extending from the rear portion of the contact portion 87a to the left, and a front portion to the left of the contact portion 87a. It has a detected portion 87c extending to. The contact portion 87a comes into contact with the damper film 83 or the pressing body 86. The support portion 87b is supported by the support spring 89. The detected portion 87c is a portion detected by the filler sensor 88.

The filler sensor 88 detects the pressure in the storage chamber 82 by detecting the position of the filler 87. The filler sensor 88 indirectly detects the pressure in the first ink supply path 72a by detecting the pressure in the storage chamber 82. Here, the filler sensor 88 of the first damper 74a is an example of the pressure detection mechanism of the present invention. In the present embodiment, the filler sensor 88 is a non-contact type sensor, but may be a contact type sensor. In this embodiment, the filler sensor 88 has a pair of detection units 88a. As shown in FIG. 5, when the detected portion 87c of the filler 87 is located between the pair of detection portions 88a, the filler sensor 88 indicates that the pressure in the storage chamber 82 is equal to or lower than a predetermined determination pressure. To detect.

As shown in FIG. 6, as the pressure in the storage chamber 82 increases, the damper film 83 bends to the outside of the storage chamber 82. At this time, the filler 87 is pushed to the outside of the storage chamber 82 by the pressing body 86, so that the filler 87 rotates about the shaft 87d located between the contact portion 87a and the support portion 87b. Then, when the pressure in the storage chamber 82 becomes higher than the predetermined determination pressure, the detected portion 87c of the filler 87 moves to a position out of the pair of the detection portions 88a of the filler sensor 88. The filler sensor 88 detects that the pressure in the storage chamber 82 is larger than a predetermined determination pressure when the detected portion 87c of the filler 87 is not located between the pair of detection portions 88a. In the present embodiment, the range between the pair of detection units 88a in the first damper 74a corresponds to the predetermined range of the present invention.

In the present embodiment, as shown in FIG. 5, when the detected portion 87c of the filler 87 is located between the pair of detection portions 88a of the filler sensor 88, that is, the pressure of the storage chamber 82 is determined to be predetermined. When the pressure is below the pressure, it is said that "filler 87 is hit". On the other hand, as shown in FIG. 6, when the detected portion 87c of the filler 87 is not located between the pair of detection portions 88a of the filler sensor 88, that is, the pressure of the storage chamber 82 is higher than the predetermined determination pressure. When it is large, it is said that "filler 87 is unhit".

As shown in FIG. 4, the ink supply system 62 has the same configuration as the ink supply system 61. In the ink supply system 62, the second ink tank 71b, the second ink supply path 72b, the second liquid feed pump 73b, and the second damper 74b are the first ink tank 71a and the first ink supply system 61, respectively. It has the same configuration as the 1 ink supply path 72a, the 1st liquid feed pump 73a, and the 1st damper 74a.

Here, the second ink tank 71b stores ink different from the ink stored in the first ink tank 71a. Here, "different ink" means that the components of the ink are different. For example, "different ink" means that the color of the ink is different. However, if the ink components are different even if the colors are the same, the inks are "different inks". In the present embodiment, different inks are ejected from the nozzle 51 and the nozzle 52. However, the same ink may be ejected from the nozzle 51 and the nozzle 52. The ink stored in the second ink tank 71b is an example of another ink of the present invention.

Although detailed description is omitted, as shown in FIG. 3, two ink supply systems 63 and 64 related to the second ink head 42, two ink supply systems 65 and 66 related to the third ink head 43, and a fourth ink The two ink supply systems 67 and 68 related to the head 44 also have the same configuration as the ink supply system 61. The inks supplied by these ink supply systems 61 to 68 may be all different inks, or some of them may be the same ink.

7 and 8 are front views of the ink heads 41 to 44 and the cap unit 110, respectively. FIG. 7 is a diagram when the ink heads 41 to 44 are located at the second position P2. FIG. 8 is a diagram when the ink heads 41 to 44 are located at the first position P1. 9, 10, and 11 are front views showing the positional relationship between the caps 111 to 114 and the nozzle surface 45. FIG. 12 is a front view of the ink heads 41 to 44 and the wiper unit 140.

Next, the cleaning system 90 will be described. The cleaning system 90 is a system for cleaning the ink heads 41 to 44, as shown in FIGS. 7 and 12. The cleaning system 90 includes a cap unit 110 and a wiper unit 140.

As shown in FIG. 7, the cap unit 110 includes first to fourth caps 111 to 114, a base 115, a spring 116 (see FIG. 9), a capping mechanism 120, and first to fourth suction pumps 131 to 11. It has 134 and. As shown in FIG. 8, the caps 111 to 114 are configured to be mounted on the nozzle surfaces 45 of the ink heads 41 to 44, respectively. Here, "mounting" means a state in which the nozzles 51 to 58 are surrounded by caps 111 to 114 in a bottom view, in other words, the end portions 118 (see FIG. 9) described later of the caps 111 to 114 are annularly formed on the nozzle surface. It refers to the state of being in contact with 45. “Mounting” means that the entire upper end of the end 118 of the caps 111 to 114 is in contact with the nozzle surface 45, and no gap is formed between the end 118 of the caps 111 to 114 and the nozzle surface 45. It refers to the state. The caps 111 to 114 cover the nozzles 51 to 58 (see FIG. 2), respectively. For example, the first cap 111 covers a plurality of nozzles 51 and a plurality of nozzles 52 formed on the nozzle surface 45 of the first ink head 41.

In this embodiment, the caps 111 to 114 have the same configuration. Therefore, the configuration of the cap 111 will be described here, and the description of the configuration of the caps 112 to 114 will be omitted. As shown in FIG. 9, the cap 111 is a hollow member. The cap 111 has an opening 117 formed at the top and an end 118 surrounding the opening 117. The end 118 constitutes the upper part of the cap 111. As shown in FIG. 11, when the cap 111 is attached to the nozzle surface 45, the end portion 118 comes into contact with the nozzle surface 45. The type of material forming the cap 111 is not particularly limited. At least a portion of the cap 111 in contact with the nozzle surface 45 (here, the end portion 118) is formed of, for example, rubber.

In this embodiment, the cap unit 110 has an absorber 119. The absorber 119 is arranged in caps 111-114. Here, the absorber 119 is placed on the bottom surface of the caps 111 to 114. The absorber 119 absorbs the ink in the caps 111 to 114. In the present embodiment, the absorber 119 is housed in caps 111-114, and the upper end of the absorber 119 is located below the upper end of the end 118. Therefore, when the caps 111 to 114 are attached to the nozzle surface 45, the absorber 119 does not come into contact with the nozzle surface 45. The specific type of the absorber 119 is not particularly limited. The absorber 119 is, for example, a sponge. Note that in FIGS. 7 and 8, the absorber 119 is not shown.

As shown in FIG. 8, a first position P1 which is a position where the ink heads 41 to 44 stand by during printing standby is set at the right end portion of the guide rail 15. The first position P1 is a so-called home position. When the ink heads 41 to 44 are located at the first position P1, caps 111 to 114 are attached to the nozzle surfaces 45 of the ink heads 41 to 44, respectively.

As shown in FIG. 7, the caps 111 to 114 are supported by the base 115. The base 115 is located below the caps 111-114. The shape of the base 115 is not particularly limited, but here it is a plate-shaped member. In this embodiment, as shown in FIG. 9, a spring 116 is provided between the cap 111 and the base 115. Although not shown, springs 116 are also provided between the caps 112 to 114 and the base 115, respectively. The number of springs 116 is not particularly limited, but in the present embodiment, the number of springs 116 is two per caps 111 to 114. The spring 116 is omitted in FIGS. 7 and 8. The spring 116 is provided so as to urge an elastic force from the base 115 toward the cap 111.

In the present embodiment, as shown in FIG. 9, when the cap 111 is not attached to the nozzle surface 45, that is, when the cap 111 is separated from the nozzle surface 45, the cap 111 is oblique to the nozzle surface 45. It is arranged at an angle. In other words, when the cap 111 is separated from the nozzle surface 45, the upper end surface of the end portion 118 of the cap 111 is inclined. Here, as shown in FIG. 10, the cap 111 is arranged at an angle with respect to the nozzle surface 45 even when a part of the end portion 118 is in contact with the nozzle surface 45. Here, the “separation” means a state in which the end portions 118 of the caps 111 to 114 are not completely in contact with the nozzle surface 45. The “separation” refers to a state in which a gap is formed over the entire surface between the end portions 118 of the caps 111 to 114 and the nozzle surface 45.

In the following description, the uppermost end 118 of the end 118 of the cap 111 is referred to as the uppermost end 118a (see FIG. 10). In the present embodiment, when the cap 111 comes into contact with the nozzle surface 45, it comes into contact with the uppermost end 118a of the end portion 118 as shown in FIG. Then, when the cap 111 is further raised, the uppermost end 118a is pressed against the nozzle surface 45, so that the spring 116 on the right side contracts and the cap 111 is tilted so as to be arranged in the horizontal direction. Then, as shown in FIG. 11, when the cap 111 is mounted on the nozzle surface 45, the cap 111 is arranged substantially horizontally. Such a configuration is the same for the caps 112 to 114.

As shown in FIGS. 7 and 8, the capping mechanism 120 attaches or separates the caps 111 to 114 from the nozzle surfaces 45 of the ink heads 41 to 44, respectively. Here, the capping mechanism 120 is a mechanism for raising and lowering the caps 111 to 114. As shown in FIGS. 9 and 10, the capping mechanism 120 is configured to tilt and move the caps 111 to 114 with respect to the nozzle surface 45. In the present embodiment, the capping mechanism 120 is configured to move the caps 111 to 114 in the main scanning direction Y and in the vertical direction in conjunction with the movement of the ink heads 41 to 44 in the main scanning direction Y. However, the capping mechanism 120 may be configured to move the caps 111 to 114 in the vertical direction while the positions of the ink heads 41 to 44 are fixed.

As shown in FIG. 7, the second position P2 is set at the right end portion of the guide rail 15 and at a position to the left of the first position P1. The second position P2 is not located directly above the platen 13 (see FIG. 1). While the ink heads 41 to 44 are moving from the second position P2 to the first position P1, the capping mechanism 120 moves the caps 111 to 114 from the second position P2 to the first position P1 while the ink heads 41 to 41. It is configured to move toward the nozzle surface 45 of 44. On the other hand, while the ink heads 41 to 44 are moving from the first position P1 to the second position P2, the capping mechanism 120 moves the caps 111 to 114 from the first position P1 to the second position P2 while moving the ink heads. It is configured to be separated from the nozzle surface 45 of 41 to 44. In the present embodiment, "controlling the capping mechanism 120" means that the caps 111 to 114 are nozzleed in conjunction with controlling the head moving mechanism 30 to move the ink heads 41 to 44 in the main scanning direction Y. It means that it is attached to or separated from the surface 45.

The specific configuration of the capping mechanism 120 is not particularly limited. In the present embodiment, the capping mechanism 120 engages with the guide member 123 in which the guide hole 122 extending diagonally upward from the second position P2 to the first position P1 is formed, and the guide hole 122, and engages with the base 115. It is provided with a support shaft 124 provided. For example, the carriage 17 is provided with a contact portion (not shown) that contacts the base 115 between the second position P2 and the first position P1.

While the ink heads 41 to 44 are moving from the second position P2 to the first position P1, the contact portion of the carriage 17 pushes the base 115 toward the first position P1. At this time, the base 115 and the caps 111 to 114 move toward the nozzle surface 45 and move from the second position P2 toward the first position P1 while being guided by the guide holes 122. At this time, the positions of the nozzle surfaces 45 of the ink heads 41 to 44 and the caps 111 to 114 change in the order of FIGS. 9, 10, and 11. Then, as shown in FIG. 8, when the ink heads 41 to 44 reach the first position P1, the caps 111 to 114 are attached to the nozzle surfaces 45 of the ink heads 41 to 44 (see FIG. 11). .. On the other hand, while the carriage 17 and the ink heads 41 to 44 are moving from the first position P1 to the second position P2, the contact portion of the carriage 17 also moves from the first position P1 to the second position P2. At this time, the base 115 and the caps 111 to 114 move apart from the nozzle surface 45 while being guided by the guide hole 122, and the base 115 comes into contact with the contact portion of the carriage 17 from the first position P1. It moves toward the second position P2. At this time, the positions of the nozzle surfaces 45 of the ink heads 41 to 44 and the caps 111 to 114 change in the order of FIGS. 11, 10, and 9. As shown in FIG. 7, the caps 111 to 114 are configured to stand by at the second position P2 when they reach the second position P2.

As shown in FIG. 7, suction pumps 131 to 134 are connected to caps 111 to 114, respectively. The suction pumps 131 to 134 are members that suck ink, air, and the like in the caps 111 to 114, respectively. In the present embodiment, for example, the suction pump 131 is an example of the suction device of the present invention. The suction pumps 131 to 134 are, for example, vacuum pumps. The suction pumps 131 to 134 are connected to the bottom surfaces of the caps 111 to 114 via tubes or the like, respectively. The suction pumps 131 to 134 are configured to form a negative pressure lower than the negative pressure in the ink supply path connected to the corresponding ink heads 41 to 44 when driven. For example, when the suction pumps 131 to 134 are driven with the caps 111 to 114 attached to the ink heads 41 to 44, ink and the like are sucked out from the nozzles 51 to 58 of the ink heads 41 to 44. The ink or the like sucked by the suction pumps 131 to 134 is discarded in a waste liquid tank (not shown) via a tube or the like (not shown).

As shown in FIG. 12, the wiper unit 140 wipes the nozzle surface 45 of the ink heads 41 to 44. The wiper unit 140 includes a wiper 141 and a wiping mechanism 145. The wiper 141 and the wiping mechanism 145 are provided between the ink heads 41 to 44 when arranged at the second position P2 (see FIG. 7) in the main scanning direction Y and the platen 13 (see FIG. 1). .. The wiper 141 and the wiping mechanism 145 are mechanisms for wiping (in other words, wiping) the nozzle surfaces 45 of the ink heads 41 to 44. The wiper 141 is a member that wipes the nozzle surfaces 45 of the ink heads 41 to 44. The wiper 141 is a flat plate-shaped member extending in the front-rear direction and the up-down direction. The length of the wiper 141 in the front-rear direction is longer than the length of the ink heads 41 to 44 in the front-rear direction. The wiper 141 is made of rubber, for example.

The wiping mechanism 145 supports the wiper 141 and brings the wiper 141 into contact with the nozzle surface 45 of the ink heads 41 to 44 and separates the wiper 141 from the nozzle surface 45 of the ink heads 41 to 44. The wiping mechanism 145 includes a rotary shaft 146, a cleaning liquid tank 147, and a rotary motor 148. The rotating shaft 146 supports one end of the wiper 141 and is connected to one end of the wiper 141. The wiper 141 can rotate about the rotation shaft 146. The rotation shaft 146 extends in the front-rear direction. When the wiper 141 is arranged in a rotational position such that the end farther from the rotation shaft 146 is facing up, the end is located slightly higher than the nozzle surface 45 of the ink heads 41-44. .. Therefore, when the carriage 17 is driven while the wiper 141 is arranged at such a rotation position, the wiper 141 can wipe the nozzle surface 45 of the ink heads 41 to 44. On the other hand, when the wiper 141 is arranged at a rotation position such that the end farther from the rotation shaft 146 is facing down, the wiper 141 is immersed in the cleaning liquid in the cleaning liquid tank 147 installed below the rotation shaft 146. The wiper 141 is rotated by a rotary motor 148.

In the present embodiment, the head moving mechanism 30 moves the ink heads 41 to 44 in the main scanning direction Y, so that the ink heads 41 to 44 are relatively moved in the main scanning direction Y with respect to the wiper 141. There is.

Next, the storage device 150 (see FIG. 1) and the control device 160 (see FIG. 1) will be described. The storage device 150 is a device that stores various parameters and the like. The control device 160 is a device that controls printing and cleaning of ink heads 41 to 44. The configuration of the storage device 150 and the control device 160 is not particularly limited. In this embodiment, the storage device 150 and the control device 160 are configured by, for example, a microcomputer. The hardware configuration of the microcomputer is not particularly limited, but for example, an interface (I / F) for receiving print data or the like from an external device such as a host computer, and a central processing unit (CPU: central) for executing control program instructions. A processing unit), a ROM (read only memory) that stores programs executed by the CPU, a RAM (random access memory) that is used as a working area for deploying programs, and a memory that stores the above programs and various data. It has. The storage device 150 and the control device 160 do not necessarily have to be provided inside the printer 100. For example, a computer installed outside the printer 100 and connected to the printer 100 by wire or wirelessly. And so on. In the present embodiment, the storage device 150 and the control device 160 are integrally configured, and are connected to each other so as to be able to communicate with each other.

FIG. 13 is a block diagram of the printer 100 according to the present embodiment. As shown in FIG. 13, the control device 160 includes a feed motor 23 of the transport mechanism 20, a carriage motor 33 of the head moving mechanism 30, ink heads 41 to 44, liquid feed pumps 73a and 73b, and dampers 74a and 74b. The filler sensor 88, the suction pumps 131 to 134, and the rotary motor 148 of the wiper unit 140 are communicably connected to each other, and are configured to be controllable.

In the present embodiment, the control device 160 includes a suction control unit 162, a first movement control unit 163, a minute open position control unit 164, a second movement control unit 165, an air suction control unit 166, and a wiping control unit. It is equipped with 167. Each part of the control device 160 described above may be composed of software or hardware. For example, each of the above-mentioned parts may be performed by a processor or may be incorporated in a circuit. The specific control of each of the above parts of the control device 160 will be described later.

The configuration of the printer 100 according to this embodiment has been described above. By the way, when cleaning the ink heads 41 to 44, an air suction process is performed. Here, the air suction processing for each of the ink heads 41 to 44 is the same processing. Therefore, in the following, the air suction treatment for the ink heads 41 will be described, and the description of the air suction treatment for the ink heads 42 to 44 will be omitted as appropriate.

In the air suction process, for example, the suction pump 131 is driven with the cap 111 separated from the nozzle surface 45 of the ink head 41 to suck the ink in the cap 111 and the nozzles 51 and 52 of the ink head 41. This is a process that does not discharge the ink inside to the cap 111. When performing the air suction process, the cap 111 may be fully filled with ink. Therefore, if the air suction process is executed with the nozzle surface 45 of the ink head 41 and the cap 111 being too far apart from each other, the ink in the cap 111 may leak to the outside. Further, when the cap 111 is removed from the nozzle surface 45 on which the cap 111 is mounted, the ink in the cap 111 may be scattered to the outside.

In the following description, the distance between the nozzle surface 45 and the cap 111 refers to the distance between the nozzle surface 45 and the portion of the end 118 of the cap 111 that is farthest from the nozzle surface 45. In the present embodiment, the cap 111 contains a mixture of ink ejected from the nozzle 51 and ink ejected from the nozzle 52. Further, the ink in the cap 111 may contain dust and the like adhering to the nozzle surface 45. During the air suction process, the negative pressure state is maintained in the nozzles 51 and 52 of the ink head 41. Therefore, if the distance between the nozzle surface 45 of the ink head 41 and the cap 111 is too large, a part of the ink in the cap 111 may adhere to the nozzle surface 45 at the timing when the cap 111 and the nozzle surface 45 are separated from each other. possible. The ink adhering to the nozzle surface 45 is a mixed ink in which colors are mixed, and is a mixed ink in which dust is mixed. At this time, since the inside of the ink head 41 has a negative pressure, the mixed ink adhering to the nozzle surface 45 may be sucked into the nozzles 51 and 52.

Although it is not directly related to the air suction process, the distance between the nozzle surface 45 of the ink head 41 and the cap 111 is zero or too narrow (here, the cap 111 is completely attached to the nozzle surface 45). Even in this case, the mixed ink in the cap 111 may be sucked into the nozzles 51 and 52. Here, the "state in which the cap 111 is completely attached to the nozzle surface 45" is a state in which there is no gap between the nozzle surface 45 and the end portion 118 of the cap 111, and the state shown in FIG. Is.

From the above, if the air suction process is executed, it is preferable that the ink in the cap 111 is hard to scatter to the outside and the mixed ink adhering to the nozzle surface 45 is hard to be sucked into the nozzles 51 and 52. .. Therefore, in the present embodiment, it is decided to perform the minute open position processing before the air suction processing. This minute open position processing will be described later.

In the present embodiment, the storage device 150 stores the suction position P51 (see FIG. 11), the empty suction position P52 (see FIG. 9), and the minute open position P53 (see FIG. 10) in advance. As shown in FIG. 11, the suction position P51 is the position of the cap 111 with respect to the nozzle surface 45 of the ink head 41 when the suction process is executed (specifically, the position of the cap 111 in the vertical direction). Here, the "suction process" refers to a process of sucking the ink in the nozzles 51 and 52 of the ink head 41 and sucking the ink in the cap 111. The suction position P51 is the position of the cap 111 such that the cap 111 is attached to the nozzle surface 45 of the ink head 41 and the entire end portion 118 of the cap 111 is in contact with the nozzle surface 45 (specifically, the upper and lower cap 111 Directional position). The suction position P51 is the position of the cap 111 when the ink in the nozzles 51 and 52 is sucked by the suction pump 131. At the suction position P51, the upper portion of the end portion 118 of the cap 111 is in a state of being crushed by the nozzle surface 45.

The air suction position P52 shown in FIG. 9 is the position of the cap 111 with respect to the nozzle surface 45 when the air suction process is executed. The air suction position P52 is a position of the cap 111 such that the end 118 of the cap 111 is separated from the nozzle surface 45 and the entire end 118 of the cap 111 is not in contact with the nozzle surface 45. At the air suction position P52, the cap 111 is arranged below the nozzle surface 45. The empty suction position P52 is the position of the cap 111 when the ink in the nozzles 51 and 52 is not sucked by the suction pump 131 and the ink in the cap 111 is sucked. In other words, the air suction position P52 is the position of the cap 111 so that ink is not sucked from the nozzles 51 and 52 when the suction pump 131 is driven.

The micro open position P53 shown in FIG. 10 is the position of the cap 111 with respect to the nozzle surface 45 when the micro open position process is being executed. Here, the minute open position processing is a process of not sucking ink from the nozzles 51 and 52 of the ink head 41 and sucking at least a part of the ink adhering to the nozzle surface 45. Here, the minute open position P53 is located between the suction position P51 and the air suction position P52. In other words, the micro open position P53 is located below the suction position P51 and above the air suction position P52. At the minute opening position P53, the distance between the nozzle surface 45 of the ink head 41 and the cap 111 is such that the ink does not leak from the inside of the cap 111 to the outside and the ink in the cap 111 is not sucked into the nozzles 51 and 52. It is a minute distance of. This minute distance is a very small distance that cannot be visually recognized. By setting the distance between the nozzle surface 45 and the cap 111 to the minute distance in this way, when the suction pump 131 is driven, the ink in the nozzles 51 and 52 is difficult to be sucked.

In the present embodiment, the micro open position P53 is in contact with the nozzle surface 45 and a part of the end portion 118 of the cap 111 (here, the uppermost end 118a), and the other part of the end portion 118 (here, the uppermost end 118a). This is the position of the cap 111 when the end portion 118 other than the above is separated. Here, "a part of the end portion 118 is in contact" means that the nozzle surface 45 and the cap 111 are in contact with each other, in addition to the case where a part of the end portion 118 of the cap 111 is in direct contact with the nozzle surface 45. A state in which a part of the end portion 118 is in contact with the ink (for example, a liquid column of ink) is also included. At the minute opening position P53, the uppermost end 118a of the cap 111 is in contact with the nozzle surface 45, but the uppermost end 118a is not crushed by the nozzle surface 45. However, the uppermost end 118a may be in a state of being crushed by the nozzle surface 45. When the uppermost end 118a is crushed by the nozzle surface 45, it is preferable that another gap is formed between the end 118 of the cap 111 and the nozzle surface 45. Further, the minute open position P53 is such that at least a gap is formed between the nozzle surface 45 of the ink head 41 and the end 118 of the cap 111, the ink in the cap 111 is sucked, and the ink is sucked from the nozzles 51 and 52. The position is adjusted so that at least a part of the ink adhering to the nozzle surface 45 of the ink head 41 can be removed. Here, "the ink is not sucked from the nozzles 51 and 52" includes not only the case where the ink is not sucked from the nozzles 51 and 52 at all but also the case where a small amount of ink is sucked from the nozzles 51 and 52. To do.

In the present embodiment, the minute open position P53 is the position of the cap 111 when the ink cannot be sucked from the nozzles 51 and 52 of the ink head 41 when sucking the ink in the cap 111. Is the position of the cap 111 when is closest to the nozzle surface 45. In other words, the minute open position P53 is the position of the cap 111 with respect to the nozzle surface 45 of the ink head 41 when the cap 111 is arranged at the uppermost position when the ink of the nozzles 51 and 52 cannot be sucked. The position. If the cap 111 is moved upward as much as possible from the state where the cap 111 is arranged at the empty suction position, the ink of the nozzles 51 and 52 can be sucked.

In the present embodiment, as shown in FIGS. 9 and 10, the distance from the nozzle surface 45 to the minute open position P53 (here, the distance in the vertical direction) is 1 / of the distance from the nozzle surface 45 to the air suction position P52. It is 10 or less. As shown in FIG. 9, the distance between the uppermost end 118a of the cap 111 and the nozzle surface 45 at the air suction position P52 is the first distance D1. As shown in FIG. 10, the distance between the uppermost end 118a of the cap 111 and the nozzle surface 45 at the minute open position P53 is the second distance D2. Here, 0 is included in the second distance D2. The second distance D2 is shorter than the first distance D1. Here, the second distance D2 is, for example, 1/10 or less of the first distance D1. However, the second distance D2 may be 1/8 or less of the first distance D1, 1/5 or less of the first distance D1, or 1/2 or less of the first distance D1. There may be.

In the present embodiment, the determination of the minute open position P53 is performed by the control device 160. As shown in FIG. 13, in order to execute the process of determining the minute open position P53, the control device 160 further separates the preprocessing execution unit 180, the approach movement control unit 181 and the approach pressure determination unit 182. It includes a movement control unit 183, a separation pressure determination unit 184, and a position storage unit 185. The above-mentioned parts of the control device 160 for determining the minute open position P53 may be configured by software or hardware. For example, each of the above-mentioned parts may be performed by a processor or may be incorporated in a circuit. The specific control of each part of the control device 160 for determining the minute open position P53 will be described later.

In the present embodiment, the processing performed by the pretreatment execution unit 180, the approach movement control unit 181, the approach pressure determination unit 182, the separation movement control unit 183, the separation pressure determination unit 184, and the position storage unit 185 is "micro open position determination processing". ". Here, the minute open position determination process is a process for determining the minute open position P53. The micro open position determination process is, for example, a process executed before the printer 100 is shipped or before the user first uses the printer 100.

Next, the procedure of the minute open position determination process will be described with reference to the flowcharts of FIGS. 14A and 14B. In the present embodiment, the process of determining each minute open position P53 of the caps 111 to 114 is the same, and therefore, the process of determining the minute open position P53 of the cap 111 will be described below.

First, in step S101 of FIG. 14A, preprocessing is executed. In this embodiment, the pre-processing execution unit 180 is programmed to execute the pre-processing. Here, the pretreatment is a process performed before the minute open position determination process. The pretreatment is a process of making the pressure in the first ink supply path 72a (see FIG. 4) and the pressure in the second ink supply path 72a (see FIG. 4) larger than a predetermined determination pressure. is there. The pretreatment execution unit 180 controls the drive of the liquid feed pumps 73a and 73b (see FIG. 4) in order to execute the pretreatment. Here, the pressure is larger than the predetermined determination pressure, as shown in FIG. 6, that the fillers 87 of the dampers 74a and 74b are both unhit, that is, between the pair of detection units 88a of the filler sensor 88 It is synonymous with the fact that the filler 87 is not located.

As the pretreatment, specifically, the pretreatment execution unit 180 determines whether or not the liquid feed pumps 73a and 73b are driven (step S1010), and when the liquid feed pumps 73a and 73b are not driven, The liquid feed pumps 73a and 73b are driven (step S1011). In the following description, "controlling the drive of the liquid feed pump" means that when the filler 87 hits, it is automatically controlled to drive (in other words, rotate) the liquid feed pump, and in other cases. Means that the liquid feed pump is automatically controlled to the standby state (for example, the stopped state). Here, the state of "controlling the drive of the liquid feed pump" is the automatic control state. Next, the pretreatment execution unit 180 determines whether or not the filler 87 has been unhit (step S1012). Here, as the ink is supplied to the ink head 41 by the liquid feed pumps 73a and 73b, the amount of ink in the storage chambers 82 of the dampers 74a and 74b gradually increases as shown in FIG. The film 83 bends outward. As a result, the filler 87 is in an unhit state. That is, the pressure in the first ink supply path 72a and the pressure in the second ink supply path 72b become larger than the predetermined determination pressure.

Here, if the determination in step S1012 is No, the preprocessing execution unit 180 waits for a predetermined waiting time (for example, 1 second) (step S1013), and determines in step S1012 again. When it is determined in step S1012 that the filler 87 is unhit, the pretreatment execution unit 180 stops driving the liquid feed pumps 73a and 73b and closes the liquid feed pumps 73a and 73b (step S1014). ). Here, the ink supply paths 72a and 72b are closed by closing the liquid feed pumps 73a and 73b. As a result, when the ink is sucked by the suction pump 131 in step S1020 described later, the ink is supplied from the ink tanks 71a and 71b to the ink supply paths 72a and 72b, and the ink is supplied to the ink supply paths 72a and 72b. It is possible to prevent the pressure drop from being hindered. The method of closing the ink supply paths 72a and 72b is not limited to closing the liquid feed pumps 73a and 73b. For example, the valves (not shown) provided in the ink supply paths 72a and 72b are closed. You may. After that, the pretreatment execution unit 180 moves the ink head 41 and the cap 111 to predetermined positions (step S1015). Here, the predetermined position is a flushing position. The flushing position is a position where flushing for ejecting ink from the ink head 41 toward the cap 111 is performed. For example, the first position P1 (see FIG. 8) and the second position P2 (see FIG. 7). It is set between.

As described above, after the pretreatment in step S101 is completed, the minute open position determination process is performed. Here, the minute open position determination process includes an approach process (step S102) and a separation process (step S103). First, in step S102, the approach process is executed. In the present embodiment, the approach processing includes an approach movement process and an approach pressure determination process. In the approach movement process, when the cap 111 is not mounted on the nozzle surface 45 (here, the ink head 41 is located at the flushing position), the cap 111 is mounted in the direction in which the cap 111 is mounted on the nozzle surface 45. Is the process of moving.

The approach pressure determination process detects the first approach detection pressure, which is the pressure in the first ink supply path 72a (see FIG. 4), while the approach movement process is being executed, and the second ink supply path 72b (FIG. 4). 4) The second approach detection pressure, which is the pressure inside, is detected, and whether or not at least one of the first approach detection pressure and the second approach detection pressure is equal to or lower than the determination pressure, that is, the dampers 74a and 74b, respectively. It is determined whether or not at least one of the fillers 87 of the above is hit. The time when at least one of the first approach detection pressure and the second approach detection pressure becomes equal to or lower than a predetermined determination pressure is when the ink in the ink head 41 is sucked by the suction pump 131. When the ink in the ink head 41 is sucked by the suction pump 131, at least one of the damper films 83 of the dampers 74a and 74b bends inward, and the ink in the storage chamber 82 decreases. Here, the approach movement control unit 181 is programmed to execute the approach movement process. The approach pressure determination unit 182 is programmed to execute the approach pressure determination process.

In the present embodiment, the approach processing of step S102 is performed according to steps S1020 to S1022. Specifically, first, the approach pressure determination unit 182 drives the first suction pump 131 for a predetermined time (for example, 10 seconds) (step S1020). Next, the approach pressure determination unit 182 determines whether or not at least one of the dampers 74a and 74b of the filler 87 has hit (step S1021). In step S1021, when at least one of the dampers 74a and 74b is hit by the filler 87, it is determined that at least one of the first approach detection pressure and the second approach detection pressure is equal to or lower than a predetermined determination pressure. .. When No is determined in step S1021, the approach movement control unit 181 heads the ink head 41 so as to move toward the first position P1 (see FIG. 8) by a predetermined distance (for example, 0.1 mm). The moving mechanism 30 is controlled (step S1022). At this time, the nozzle surface 45 of the ink head 41 and the cap 111 are brought close to each other by the capping mechanism 120 linked with the head moving mechanism 30. After that, the control of step S1020 is performed again.

On the other hand, if it is determined in step S1021 that at least one of the dampers 74a and 74b of the filler 87 has hit, the process proceeds to Yes, and the approach process of step S102 ends. As described above, at least one of the fillers 87 of the dampers 74a and 74b was hit because the ink was sucked from at least one of the nozzles 51 and 52 and the pressure of at least one of the pressures of the ink supply paths 72a and 72b was hit. Is due to the change. The state in which the ink in the ink head 41 is sucked is also referred to as a state in which the cap 111 is attached to the nozzle surface 45 of the ink head 41.

Next, in step S103 of FIG. 14B, the separation process is executed. The separation process includes a separation movement process, a separation pressure determination process, and a position memory process. In the separation movement process, the cap 111 is attached to the nozzle surface 45 when it is first determined in the approach pressure determination process that at least one of the first approach detection pressure and the second approach detection pressure is equal to or lower than the determination pressure. In this state, the cap 111 is moved in the direction in which the cap 111 is separated from the nozzle surface 45.

The separation pressure determination process detects the first separation detection pressure, which is the pressure in the first ink supply path 72a (see FIG. 4), while the separation movement processing is being executed, and determines that the first separation detection pressure is a predetermined pressure. Determine if it is greater than the pressure. Here, the separation pressure determination process detects the first separation detection pressure while the separation movement processing is being executed, and also detects the second separation, which is the pressure in the second ink supply path 72b (see FIG. 4). The pressure is detected, and it is determined whether or not both the first separation detection pressure and the second separation detection pressure are larger than the determination pressure, that is, whether or not the fillers 87 of the dampers 74a and 74b both hit. The time when both the first separation detection pressure and the second separation detection pressure become larger than the predetermined determination pressure is when the ink in the ink head 41 is released from the state of being sucked by the suction pump 131. When the ink in the ink head 41 is no longer sucked by the suction pump 131, the damper films 83 of the dampers 74a and 74b are maintained in a bent outward state as shown in FIG.

The position storage process is a process of storing the position of the cap 111 with respect to the nozzle surface 45 in the storage device 150 as a minute open position P53 when the first separation detection pressure is first determined to be larger than the determination pressure in the separation pressure determination process. Is. Here, in the position memory processing, the position of the cap 111 with respect to the nozzle surface 45 is slightly opened when it is first determined in the separation pressure determination processing that both the first separation detection pressure and the second separation detection pressure are larger than the determination pressure. It is stored in the storage device 150 as the position P53. In the present embodiment, the separation movement control unit 183 is programmed to execute the separation movement processing. The separation pressure determination unit 184 is programmed to execute the separation pressure determination process. The position stored unit 185 is programmed to execute the position storage process.

In the present embodiment, the separation process of step S103 is performed according to steps S103 to S1036. Specifically, first, the separation pressure determination unit 184 drives the liquid feed pumps 73a and 73b (step S1030) and waits for a predetermined time (for example, 3 seconds) (step S1031). After that, the separation pressure determination unit 184 stops driving the liquid feed pumps 73a and 73b, and closes the liquid feed pumps 73a and 73b (step S1032). By performing these steps, the filler 87 of the dampers 74a and 74b can be unhit.

Next, the separation pressure determination unit 184 drives the suction pump 131 for a predetermined time (for example, 10 seconds) (step S1033). After that, the separation pressure determination unit 184 determines whether or not the fillers 87 of the dampers 74a and 74b are hit, that is, whether or not the filler 87 has changed from the unhit state (step S1034). Here, when the fillers 87 of the dampers 74a and 74b are unhit, it is determined that the first separation detection pressure and the second separation detection pressure are larger than the predetermined determination pressures. If it is determined to be Yes in step S1034, the ink in the ink head 41 is sucked by the suction pump 131, and the ink in the storage chamber 82 is reduced. In this case, the separation movement control unit 183 controls the head movement mechanism 30 so that the ink head 41 moves toward the second position P2 (see FIG. 7) by a predetermined distance (for example, 0.1 mm) (step). S1035). At this time, the capping mechanism 120 linked to the head moving mechanism 30 moves the ink head 41 in a direction away from the nozzle surface 45 and the cap 111. After that, the separation pressure determination unit 184 controls step S1030 again.

On the other hand, when it is determined in step S1034 that the fillers 87 of the dampers 74a and 74b are unhit, the ink in the ink head 41 is not sucked by the suction pump 131, and the amount of ink in the storage chamber 82 changes. It is not in the state. In this case, the process proceeds to No. Then, in step S1036, the position storage unit 185 stores the position of the cap 111 with respect to the nozzle surface 45 of the ink head 41 in the storage device 150. At this time, the position stored unit 185 may store the position of the ink head 41 in the main scanning direction Y in the storage device 150. The position of the cap 111 at this time is a position where the ink in the nozzles 51 and 52 is no longer sucked by the cap 111. The position of the cap 111 at this time is the minute open position P53.

In the present embodiment, the "drive" of the suction pump includes not only a state in which the suction pump is always driven, but also a state in which the suction pump is temporarily not driven, that is, stopped. You may be. To "drive" the suction pump, for example, while the caps 111 to 114 are moving away from the nozzle surface 45, the suction pump is stopped for at least a part of the time, or the suction force of the suction pump is appropriately changed. The state of making it is included. In the present embodiment, the suction pumps 131 to 134 are always driven while the caps 111 to 114 are moving in the direction away from the nozzle surface 45. At this time, the suction pumps 131 to 134 are driven so that the maximum suction force is maintained. While the suction pumps 131 to 134 are being driven, the suction force of the suction pumps 131 to 134 may change.

The micro open position determination process has been described above. FIG. 15 is a flowchart showing a cleaning procedure for the ink heads 41 to 44. Next, the cleaning procedure for the ink heads 41 to 44 will be described with reference to the flowchart shown in FIG. In the present embodiment, the cleaning procedure for each of the ink heads 41 to 44 is the same. Therefore, here, the cleaning procedure for the ink head 41 will be described, and the description for the cleaning procedure for the other ink heads 42 to 44 will be omitted as appropriate.

In the present embodiment, as shown in FIG. 15, as cleaning for the ink heads 41 to 44, a suction process (step S201), a minute open position process (step S203), an air suction process (step S205), and a wiping process (step S205) are performed. Step S206) is executed in order. Each of the above processes is executed by the control device 160. In FIG. 15, in the processes of steps S201 to S205, the processes are simultaneously performed on the four ink heads 41 to 44. The processing of step S206 is processing for the ink heads 41 to 44 in order. Before the suction process of step S201 is executed, as shown in FIG. 13, the storage device 150 stores in advance the minute open position P53 determined according to the flowcharts of FIGS. 14A and 14B described above. ing. Further, the suction position P51 and the empty suction position P52 are stored in advance in the storage device 150.

First, in step S201 of FIG. 15, the suction process is performed. In this embodiment, the suction control unit 162 of FIG. 13 is programmed to execute the suction process. The suction process is a process performed with the cap 111 arranged at the suction position P51 (see FIG. 11). The suction process is a process in which the cap 111 is attached to the nozzle surface 45 of the ink head 41 and ink is sucked from the nozzles 51 and 52 of the ink head 41 as described above. In other words, in the suction process, the ink in the nozzles 51 and 52 of the ink head 41 is discharged to the cap 111. Here, the suction control unit 162 indirectly controls the capping mechanism 120 by first controlling the head moving mechanism 30 so that the cap 111 is arranged at the suction position P51. Specifically, the suction control unit 162 controls the head moving mechanism 30 so as to move the ink head 41 to the first position P1 as shown in FIG. At this time, the cap 111 gradually moves toward the nozzle surface 45 of the ink head 41 by the capping mechanism 120 linked with the control of the head moving mechanism 30, and at the first position P1, as shown in FIG. 11, the ink head A cap 111 is attached to the nozzle surface 45 of 41, and the cap 111 is arranged at the suction position P51.

FIG. 16 shows the position of the cap 111 in each process, the contact between the end 118 of the cap 111 and the absorber 119 and the nozzle surface 45, the pressure in the cap 111, the drive of the suction pump 131, and the first and second movement processes. It is a figure which showed the movement amount per unit time of the cap 111 at the time of. As shown in FIG. 16, at the suction position P51 of the suction process, the nozzle surface 45 and the entire end 118 of the cap 111 are in complete contact with each other, and the nozzle surface 45 and the cap 111 are in complete contact with each other. , A closed space is formed. At the suction position P51, the absorber 119 is not in contact with the nozzle surface 45.

In this way, with the cap 111 arranged at the suction position P51, the suction control unit 162 drives the suction pump 131 to create a negative pressure inside the cap 111. The specific value of the pressure in the cap 111 at this time is not particularly limited, but is, for example, −5 kPa or less. In the present embodiment, the inside of the cap 111 becomes negative pressure by the control by the suction control unit 162, and the ink in the nozzles 51 and 52 of the ink head 41 is discharged to the cap 111. The ink discharged into the cap 111 is a mixed ink in which the ink in the nozzle 51 and the ink in the nozzle 52 are mixed.

In the present embodiment, after the suction process, the so-called negative pressure adjustment process is not executed, and the processes after step S202 are executed. Here, the negative pressure adjusting process is a process of stopping the suction pump 131 for a predetermined time while the cap 111 is attached to the nozzle surface 45 of the ink head 41.

After the suction process is executed, the first movement process is performed in step S202 of FIG. The first moving process is an example of the moving process of the present invention. In the present embodiment, the first movement control unit 163 is programmed to execute the first movement processing. The first movement process is a process of moving the cap 111 toward the minute open position P53. In the suction process of step S201, since the cap 111 is arranged at the suction position P51, in the first movement process, the cap 111 is moved from the suction position P51 to the minute open position P53. The first movement control unit 163 controls the head movement mechanism 30 so that the cap 111 is arranged at the minute opening position P53 stored in the storage device 150.

As shown in FIG. 16, when the cap 111 is moved toward the minute opening position P53 by the first movement process, the end portion 118 of the cap 111 is in contact with the nozzle surface 45, and the cap 111 is in contact with the nozzle surface 45. Is placed at the micro open position P53, a part of the end 118 of the cap 111 (here, the uppermost 118a) is in contact with the nozzle surface 45, and the other part of the end 118 is separated from the nozzle surface 45. It becomes a state. Further, the absorber 119 is not in contact with the nozzle surface 45 while the cap 111 is moved to the minute opening position P53 by the first movement process.

In the present embodiment, the first movement control unit 163 stops the suction pump 131 while the first movement processing is being executed. That is, the ink in the cap 111 is not sucked by the suction pump 131 while the first movement process is being executed. However, since the inside of the cap 111 has a negative pressure in step S201, the negative pressure state is maintained inside the cap 111 in the first movement process of step S202. However, in the first movement process, the pressure inside the cap 111 is negative, but the value is equal to or less than the pressure at the time of the suction process (for example, −5 kPa).

Further, when the first movement control unit 163 moves the cap 111 toward the minute opening position P53 while the first movement processing is being executed, the movement amount of the cap 111 per unit time is the first movement amount. It is M1. In other words, the first movement control unit 163 moves the cap 111 at the first speed. Here, the movement amount of the cap 111 means the movement amount of the portion of the end portion 118 of the cap 111 that is first separated from the nozzle surface 45. However, the portion that serves as a reference for the movement amount of the cap 111 is not particularly limited. For example, the movement amount of the cap 111 may be the movement amount of the center of the cap 111 or the movement amount of the lowermost end of the cap 111.

After executing the first movement process, in step S203 of FIG. 15, the minute open position process is executed. In this embodiment, the micro open position control unit 164 is programmed to execute the micro open position process. The micro open position process is a process performed in a state where the cap 111 is arranged at the micro open position P53 (see FIG. 10). As shown in FIG. 10, the micro open position P53 is when the nozzle surface 45 and a part of the end 118 of the cap 111 (here, the uppermost end 118a) are in contact with each other and the other part of the end 118 is separated. This is the position of the cap 111 of the above, which is the position determined according to the flowcharts of FIGS. 14A and 14B as described above. At the micro open position P53, the absorber 119 is not in contact with the nozzle surface 45. For example, the mixed ink in the cap 111 may adhere to the nozzle surface 45 of the ink head 41. However, the mixed ink adhering to the nozzle surface 45 is in a state of being connected to the mixed ink in the cap 111 when the cap 111 is arranged at the minute opening position P53.

As a specific process of the minute open position process, the minute open position control unit 164 drives the suction pump 131 as shown in FIG. 16 in a state where the cap 111 is arranged at the minute open position P53. Further, the micro open position control unit 164 is configured to keep the cap 111 at the micro open position P53 for a predetermined time. Therefore, in the micro open position processing, the suction pump 131 continues to be driven for a predetermined time. Here, the predetermined time is stored in the storage device 150 in advance. The predetermined time is appropriately set according to the amount of ink to be sucked from the ink in the cap 111 by the minute open position processing. In the present embodiment, a minute gap is formed between the end portion 118 of the cap 111 and the nozzle surface 45 at the minute opening position P53. Therefore, the outside air is sucked through the gap. In the micro open position processing, the inside of the cap 111 has a negative pressure, but the value is, for example, −5 kPa or less.

In the micro open position processing, the ink in the cap 111 is sucked. Further, in the present embodiment, when the mixed ink adheres to the nozzle surface 45, the mixed ink adhering to the nozzle surface 45 is connected to the ink in the cap 111 as described above, so that the mixed ink is in the cap 111. Together with the ink, it is sucked by the suction pump 131. Therefore, the mixed ink is unlikely to remain on the nozzle surface 45.

After the minute open position processing, the second movement processing is executed in step S204 of FIG. The second moving process is an example of another moving process of the present invention. In the present embodiment, the second movement control unit 165 is programmed to execute the second movement processing. The second movement process is a process of moving the cap 111 toward the air suction position P52 (see FIG. 9). In the micro-opening position processing in step S203, the cap 111 is arranged at the micro-opening position P53. Therefore, in the second movement processing, the cap 111 is moved from the micro-opening position P53 to the air suction position P52. The second movement control unit 165 controls the head movement mechanism 30 so that the cap 111 is arranged at the air suction position P52 stored in the storage device 150. In the second movement process, the cap 111 may be configured to move in a tilted state, or may be configured to move without being tilted.

When the cap 111 is moving toward the minute opening position P53 by the second movement process, the entire end portion 118 of the cap 111 is not in contact with the nozzle surface 45, and the absorber 119 is also on the nozzle surface. Not in contact with 45. In the present embodiment, the second movement control unit 165 stops the suction pump 131 while the second movement process is being executed. That is, the ink in the cap 111 is not sucked by the suction pump 131 while the second movement process is being executed. Therefore, the inside of the cap 111 becomes atmospheric pressure.

Further, when the second movement control unit 165 moves the cap 111 toward the air suction position P52 while the second movement processing is being executed, the movement amount of the cap 111 per unit time is the second movement amount M2. (See FIG. 16). In other words, the second movement control unit 165 moves the cap 111 at the second speed. Here, the second movement amount M2 is larger than the first movement amount M1 which is the movement amount of the cap 111 in the first movement process in step S202. In other words, the second speed is faster than the first speed, which is the moving speed of the cap 111 in the first moving process. That is, in the second movement process, the cap 111 is moved faster than in the first movement process.

After the second movement process, in step S205 of FIG. 15, the air suction process is executed. In this embodiment, the air suction control unit 166 is programmed to perform the air suction process. The air suction process is a process performed with the cap 111 arranged at the air suction position P52 (see FIG. 9). At the air suction position P52, the entire end 118 of the cap 111 is not in contact with the nozzle surface 45, and the absorber 119 is also not in contact with the nozzle surface 45.

In the air suction process, the air suction control unit 166 drives the suction pump 131 as shown in FIG. 16 with the cap 111 arranged at the air suction position P52. In the present embodiment, the cap 111 is separated from the nozzle surface 45 at the air suction position P52. Therefore, the outside air is sucked from between the cap 111 and the nozzle surface 45. In the air suction process, the inside of the cap 111 has a negative pressure, but the value is, for example, −5 kPa or less. In the air suction process, the ink in the cap 111 is sucked, but the ink adhering to the nozzle surface 45 and the ink in the nozzles 51 and 52 are not sucked.

After the air suction process, the wiping process is performed in step S206 of FIG. In this embodiment, the wiping control unit 167 is programmed to execute the wiping process. The wiping process is a process of wiping the nozzle surface 45 with the wiper 141 after the minute open position process and the air suction process. Here, the wiping control unit 167 controls the head moving mechanism 30 so that the ink head 41 moves above the wiping mechanism 145 (see FIG. 12). Then, when the ink head 41 passes above the wiping mechanism 145, the wiping control unit 167 rotates the wiper 141, and the wiper 141 wipes the nozzle surface 45 of the ink head 41. Here, the ink heads 41, 42, 43, and 44 are not wiped at the same time, but the ink heads 41, 42, 43, and 44 are wiped in this order. By executing the above steps, cleaning of the ink heads 41 to 44 is completed.

As described above, in the present embodiment, as shown in FIG. 13, the storage device 150 stores the suction position P51, the empty suction position P52, and the minute open position P53. As shown in FIG. 11, the suction position P51 is the cap 111 when the end 118 of the cap 111 is in contact with the nozzle surface 45 and the ink in the nozzles 51 and 52 is sucked by the suction pump 131. The position. As shown in FIG. 9, the air suction position P52 is the cap 111 when the end 118 of the cap 111 is separated from the nozzle surface 45 and the ink in the nozzles 51 and 52 is not sucked by the suction pump 131. The position. The micro open position P53 shown in FIG. 10 is located between the suction position P51 and the air suction position P52. The control device 160 sucks ink from the nozzles 51 and 52 with the cap 111 arranged at the suction position P51 (step S201 in FIG. 15), and after the suction process, moves the cap 111 to the minute open position P53. After the first movement process (step S202 in FIG. 15) and the first movement process, the movement of the cap 111 is stopped in the state where the cap 111 is arranged at the minute opening position P53 (FIG. 15). It is configured to execute step S203) of 15.

In the present embodiment, after the suction process (step S201 in FIG. 15), the so-called negative pressure adjustment process is not executed, but the minute open position process (step S203 in FIG. 15) is executed. When the suction pump 131 is driven during the suction process, the inside of the cap 111 becomes negative pressure. With the inside of the cap 111 having a negative pressure, the cap 111 is moved to the minute open position P53 by the first movement process (step S202 in FIG. 15), and the minute open position process is executed. Immediately after the minute open position processing is executed, the ink in the cap 111 is sucked because the pressure inside the cap 111 is negative. As described above, in the printer 100 according to the present embodiment, the so-called negative pressure adjustment process is not executed, but the minute open position process in which the ink in the cap 111 is sucked is executed. Therefore, since the time required for the negative pressure adjustment process can be shortened, the time at which the ink in the cap 111 may enter the nozzles 51 and 52 can be shortened. Therefore, it is possible to make it difficult for the ink in the cap 111 to enter the nozzles 51 and 52.

Further, in the present embodiment, the end portion 118 of the cap 111 is closer to the nozzle surface 45 in the micro open position P53, which is the position of the cap 111 in the micro open position processing, as compared with the air suction position P52. The position. Therefore, since the gap between the nozzle surface 45 and the cap 111 can be made relatively small, it is possible to prevent the ink in the cap 111 from scattering.

In the present embodiment, as shown in FIGS. 9 and 10, the distance between the uppermost end 118a of the cap 111 and the nozzle surface 45 at the air suction position P52 is the first distance D1. The distance between the uppermost end 118a of the cap 111 and the nozzle surface 45 at the minute open position P53 is the second distance D2 which is 1/10 or less of the first distance D1. As a result, at the minute open position P53, the end 118 of the cap 111 is closer to the nozzle surface 45 than at the air suction position P52. Therefore, at the minute open position P53, the gap between the nozzle surface 45 and the end portion 118 of the cap 111 can be made smaller. Therefore, it is possible to make it more difficult for the ink in the cap 111 to enter the nozzles 51 and 52 when the minute open position processing is being executed.

In the present embodiment, the control device 160 stops the suction pump 131 as shown in FIG. 16 when executing the first movement process of moving the cap 111 from the suction position P51 to the minute open position P53. It is configured. For example, in the suction process and the minute open position process, the dampers 74a and 74b (see FIG. 4) perform a process of detecting the amount of ink in the ink supply paths 72a and 72b (see FIG. 4). Here, if the suction pump 131 is driven while the first movement process is being executed, there is a variation between the amount of ink detected in the suction process and the amount of ink detected in the minute open position process. It can occur. However, in the present embodiment, since the suction pump 131 is stopped when the first movement process is being executed, the occurrence of the above-mentioned variation can be suppressed.

In the present embodiment, as shown in FIG. 10, in the micro open position P53, a part of the end portion 118 (here, the uppermost end 118a) of the cap 111 is in contact with the nozzle surface 45, and the other end portion 118 is other. This is the position of the cap 111 when a part (here, the upper end other than the uppermost end 118a) is separated from the nozzle surface 45. As a result, when the cap 111 arranged at the suction position P51 (see FIG. 11) moves toward the minute open position P53, as shown in FIG. 10, all the upper ends of the end 118s of the cap 111 are nozzles at the same time. Without leaving the surface 45, the end 118 in turn separates from the nozzle surface 45. In one example of FIG. 10, the nozzle surface 45 is gradually separated from the left side portion of the end portion 118. Therefore, when the cap 111 attached to the nozzle surface 45 is separated from the nozzle surface 45, the ink adhering to the end portion 118 of the cap 111 is unlikely to scatter.

Further, in the present embodiment, the capping mechanism 120 (see FIG. 7) of the cap unit 110 (see FIG. 7) is configured to tilt and move the cap 111 with respect to the nozzle surface 45 as shown in FIG. ing. As a result, the upper end surface of the cap 111 can be tilted by a simple method of tilting the cap 111 itself.

In the present embodiment, the control device 160 is configured to drive the suction pump 131 as shown in FIG. 16 when the minute open position process is being executed. As a result, the ink in the cap 111 can be positively sucked by the suction pump 131 in the micro open position processing.

In the present embodiment, the control device 160 is configured to keep the cap 111 at the micro open position P53 for a predetermined time while executing the micro open position process. At the minute opening position P53, a minute gap is formed between the cap 111 and the nozzle surface 45, and the atmosphere is taken into the cap 111 through the gap. Therefore, by maintaining the state in which the cap 111 is arranged at the minute open position P53 for a predetermined time, it is easy to shift to the direction in which the negative pressure in the cap 111 is released.

In the present embodiment, the control device 160 has a second movement process (step S204 in FIG. 15) for moving the cap 111 toward the air suction position P52 after the minute open position process, and a cap after the second move process. The air suction process for driving the suction pump 131 is executed with the 111 placed at the air suction position P52. As shown in FIG. 16, the movement amount of the cap 111 per unit time in the first movement process (step S202 of FIG. 15) is the first movement amount M1. The movement amount of the cap 111 per unit time in the second movement processing is the second movement amount M2, which is larger than the first movement amount M1. As a result, the moving speed of the cap 111 in the first moving process is slower than the moving speed of the cap 111 in the second moving process. Therefore, in the first movement process, the ink in the cap 111 can be prevented from leaking from the upper part.

In the present embodiment, the absorber 119 is arranged away from the nozzle surface 45 at the minute open position P53. If the absorber 119 is in contact with the nozzle surface 45, the nozzle surface 45 may be damaged by the absorber 119, and as a result, ejection defects of the nozzles 51 and 52 may occur. However, in the present embodiment, since the absorber 119 is not in contact with the nozzle surface 45, it is possible to prevent the nozzle surface 45 from being damaged by the absorber 119.

In the present embodiment, in the nozzles 51 and 52 formed on the nozzle surface 45 of the ink head 41, the ink ejected from the nozzle 51 is different from the ink ejected from the nozzle 52. The control device 160 performs a wiping process in which the cap 111 is separated from the nozzle surface 45 and the nozzle surface 45 is wiped by the wiper 141 after at least the minute open position process. In the present embodiment, during the suction process, mixed ink in which two different types of ink sucked from the nozzles 51 and 52 are mixed is stored in the cap 111. In the micro open position processing, the mixed ink in the cap 111 is sucked while the cap 111 is moved to the micro open position P53. In the micro open position processing, for example, even when the mixed ink adheres to the nozzle surface 45, the mixed ink adhering to the nozzle surface 45 is easily sucked together with the mixed ink in the cap 111. Therefore, in the wiping process, when wiping the nozzle surface 45, it is difficult for mixed ink to enter the nozzles 51 and 52 of the ink head 41.

In the present embodiment, the control device 160 is configured to execute the minute open position determination process for determining the minute open position P53. The minute open position determination process includes a separation movement process, a separation pressure determination process, and a position memory process. For example, by driving the suction pump 131 while the cap 111 is mounted on the nozzle surface 45 of the ink head 41, the ink in the ink head 41 is sucked and discharged into the cap 111. At this time, the pressure in the ink supply paths 72a and 72b related to the ink head 41 drops because the ink is discharged, and becomes equal to or lower than the predetermined detection pressure. On the other hand, when the pressure in the ink supply paths 72a and 72b is larger than the predetermined detection pressure, the ink in the ink head 41 is not sucked. In this way, the position of the cap 111 with respect to the nozzle surface 45 when switching from the case where the ink in the ink head 41 is discharged by the suction pump 131 to the case where the ink is not discharged sucks the ink in the cap 111 and This is a position in the nozzles 51 and 52 where the ink is not sucked, and the cap 111 is closest to the nozzle surface 45. In the present embodiment, by detecting the pressure in the ink supply paths 72a and 72b, it is possible to suck the ink in the cap 111 and not to suck the ink in the nozzles 51 and 52, and the nozzle surface. The position where the cap 111 is closest to the 45 can be set. By setting such a position as the minute opening position P53 and performing the minute opening position processing at the minute opening position P53, it is possible to suppress the mixed ink from entering the ink head 41. Further, since the cap 111 is relatively close to the nozzle surface 45, it is possible to prevent the ink in the cap 111 from leaking to the outside. Therefore, the minute open position processing can be appropriately performed.

In the present embodiment, before the separation process (step S103 in FIG. 14B) including the separation movement process and the separation pressure determination process is performed, the approach process including the approach movement process and the approach pressure determination process (step S102 in FIG. 14A) is performed. ) Is being performed. Here, in the approach process, the timing of switching from the case where the ink in the ink head 41 is not sucked by the suction pump 131 to the case where the ink is sucked is determined. On the other hand, in the separation process, the timing of switching from the case where the ink in the ink head 41 is sucked by the suction pump 131 to the case where the ink is not sucked is determined. The ink sucked by the suction pump 131 is discarded and becomes useless ink. Therefore, the longer the processing time of the separation process, the more ink is discarded, and the ink is wasted. However, in the present embodiment, by performing the approaching process before the separating process, it is possible to specify the approximate position where the ink in the ink head 41 is not sucked by the suction pump 131. Therefore, by performing the separation process after the approach process, the processing time of the separation process can be relatively shortened, and the amount of ink sucked by the suction pump 131 can be reduced. Therefore, the amount of ink discarded can be reduced by performing control for determining the minute open position P53.

The dampers 74a and 74b shown in FIG. 5 are used to control the timing of ink supply during printing. In the present embodiment, the filler sensor 88 of the dampers 74a and 74b is used to detect the pressure of the ink supply paths 72a and 72b to determine the minute open position P53. Therefore, since it is not necessary to provide a dedicated pressure sensor for determining the minute open position P53 in the ink supply paths 72a and 72b, the number of parts can be reduced and the manufacturing cost can be suppressed.

In this embodiment, the suction process, the first movement process, the minute open position process, the second movement process, the air suction process, and the wiping process executed by the control device 160 are for cleaning to be realized by the computer. Includes computer programs. Further, in the present embodiment, a computer performs a minute open position determination process (specifically, approach movement process, approach pressure determination process, separation movement process, separation pressure determination process, and position storage process) executed by the control device 160. Includes a computer program for micro-open position determination to achieve this.

The inkjet printer 100 according to this embodiment has been described above. In the above embodiment, the suction pumps 131 to 134 are stopped in the first movement process in step S202 and the second movement process in step S204. However, in the first movement process, the first movement control unit 163 may be controlled to drive the suction pumps 131 to 134. In the second movement process, the second movement control unit 165 may be controlled to drive the suction pumps 131 to 134.

In the above embodiment, the suction pumps 131 to 134 were driven in the micro open position processing in step S203. However, the suction pumps 131 to 134 may be stopped in the micro open position processing. Even in this case, the negative pressure state in the cap 111 in the suction process and the first movement process is maintained even in the minute open position process, so that the ink in the cap 111 is sucked. Therefore, since the so-called negative pressure adjustment process can be omitted, the time during which the ink in the cap 111 may enter the nozzle can be shortened. Therefore, it is possible to make it difficult for the ink in the cap 111 to enter the nozzles 51 and 52. In addition, in order to stop the suction pumps 131 to 134 in the minute open position processing, when the negative pressure in the cap 111 is high (for example, the pressure at the time of the normal suction processing, for example, about -50 kPa or less), or It is preferable that the air suction process of step S205 is executed without being omitted.

In the above embodiment, the suction pumps 131 to 134 were driven in the air suction process in step S205. However, when most of the ink in the cap 111 (for example, 90% or more of the ink in the cap 111) is sucked in the minute open position processing in step S203, the air suction control unit 166 uses the suction pumps 131 to 131. It may be controlled to stop 134. When most of the ink in the cap 111 is sucked in the micro open position processing in step S203, the second movement processing in step S204 and the air suction processing in step S205 may be omitted. In this case, the micro open position process includes an air suction process.

In the above embodiment, the cap 111 is tilted between the suction position P51 and the micro open position P53 and between the micro open position P53 and the sky in a state where the end 118 of the cap 111 is tilted by tilting the cap 111 itself. It is moving between the suction position P52. However, as in other embodiments of FIG. 17, the cap 111 may be configured to be movable without being tilted. In this case, the upper end surface of the end portion 118 of the cap 111 may be inclined. When the upper end surface of the end portion 118 is inclined, it means that the upper end surface of the end portion 118 is inclined with respect to the bottom surface of the cap 111. As a result, the upper end surface of the end portion 118 can be tilted with respect to the nozzle surface 45 without tilting the cap 111 itself.

In the above embodiment, at the micro open position P53, a part of the end portion 118 of the cap 111 (here, the uppermost end 118a) is in contact with the nozzle surface 45, and the other part of the end portion 118 is separated from the nozzle surface 45. Was. However, at the minute open position P53, the uppermost end 118a of the end portion 118 of the cap 111 does not contact the nozzle surface 45, and a slight gap is formed between the uppermost end 118a and the nozzle surface 45. May be good.

In the above embodiment, different types of ink are ejected from one ink head. Two ink supply systems were connected to one ink head. However, the same ink may be ejected from one ink head. One ink supply system may be connected to one ink head.

In the above embodiment, the capping mechanism 120 raises and lowers the caps 111 to 114 in conjunction with the head moving mechanism 30. However, the capping mechanism according to the present invention includes a drive motor, and the caps 111 to 114 may be raised and lowered by driving the drive motor. Further, the capping mechanism according to the present invention may be configured to raise and lower the caps 111 to 114 at the first position P1 after the ink heads 41 to 44 reach the first position P1.

In the above embodiment, the approach process (step S102 in FIG. 14A) is followed by the separation process (step S103 in FIG. 14B). However, this approach process can be omitted. In this case, the separation process may be started from a position (for example, the first position P1) in which the caps 111 to 114 are attached to the nozzle surface 45.

In the above embodiment, in the approach pressure determination process (here, control of the approach pressure determination unit 182), it is determined whether or not at least one of the first approach detection pressure and the second approach detection pressure is equal to or less than the determination pressure. Was there. Then, in the separation movement processing (here, control of the separation movement control unit 183), when at least one of the first approach detection pressure and the second approach detection pressure is equal to or lower than the determination pressure, the cap 111 with respect to the nozzle surface 45 The caps 111 to 114 were moved in the direction in which ~ 114 were separated from each other. However, the approach pressure determination unit 182 may determine whether or not both the first approach detection pressure and the second approach detection pressure are equal to or less than the determination pressure. In this case, in the separation movement control unit 183, the caps 111 to 114 are separated from the nozzle surface 45 by the approach pressure determination unit 182 when both the first approach detection pressure and the second approach detection pressure are equal to or lower than the determination pressure. The caps 111 to 114 are moved in the direction.

In the above embodiment, the first pressure detection mechanism and the second pressure detection mechanism of the present invention are the filler sensors 88 of the dampers 74a and 74b. However, the first pressure detection mechanism and the second pressure detection mechanism may be so-called pressure sensors provided in the ink supply paths 72a and 72b.

41 Ink head 45 Nozzle surface 51 Nozzles 52 Nozzles (other nozzles)
100 printer (invertical printer)
110 Cap unit 111-114 Cap 120 Capping mechanism 131-134 Suction pump (suction device)
141 Wiping 145 Wiping mechanism 150 Storage device 160 Control device 162 Suction control unit 163 1st movement control unit 164 Micro open position control unit 165 2nd movement control unit 166 Air suction control unit 167 Wiping control unit

Claims (17)

An ink head having a nozzle surface with a nozzle for ejecting ink,
A cap that can be mounted on the nozzle surface so as to cover the nozzle and has an end that can come into contact with the nozzle surface when mounted on the nozzle surface, a suction device connected to the cap, and the above. A cap unit having a capping mechanism for attaching or separating the cap from the nozzle surface,
The suction position, which is the position of the cap when the end of the cap is in contact with the nozzle surface and the ink in the nozzle is sucked by the suction device, and the end of the cap are said. It is located away from the nozzle surface and at the air suction position, which is the position of the cap when the ink in the nozzle is not sucked by the suction device, and between the suction position and the air suction position. A storage device that stores the minute open position in advance,
Control device and
With
The control device
With the cap placed at the suction position, a suction process that sucks ink from the nozzle and
After the suction process, a moving process of moving the cap toward the minute open position and a moving process.
After the movement process, the micro open position process for stopping the movement of the cap with the cap placed at the micro open position,
An inkjet printer configured to run. When the uppermost end of the cap is the uppermost end,
The distance between the uppermost end of the cap and the nozzle surface at the air suction position is the first distance.
The inkjet printer according to claim 1, wherein the distance between the uppermost end of the cap and the nozzle surface at the minute open position is a second distance of 1/10 or less of the first distance. The inkjet printer according to claim 1 or 2, wherein the control device is configured to stop the suction device when the movement process is being executed. The micro open position is the position of the cap when a part of the end portion of the cap is in contact with the nozzle surface and the other part of the end portion is away from the nozzle surface. The inkjet printer according to any one of claims 1 to 3. The inkjet printer according to claim 4, wherein the capping mechanism of the cap unit is configured to tilt and move the cap with respect to the nozzle surface. The inkjet printer according to any one of claims 1 to 5, wherein the control device is configured to drive the suction device when the micro open position process is being executed. The control device is configured to keep the cap in the micro-open position for a predetermined time when the micro-open position process is being executed, according to any one of claims 1 to 6. Described inkjet printer. The control device
After the micro open position process, another movement process of moving the cap toward the air suction position, and
After the other movement process, the air suction process for driving the suction device with the cap placed at the air suction position,
Is configured to run
The movement amount of the cap per unit time in the movement processing is the first movement amount.
The inkjet printer according to any one of claims 1 to 7, wherein the movement amount of the cap per unit time in the other movement processing is a second movement amount larger than the first movement amount. The cap unit has an absorber disposed within the cap.
The inkjet printer according to any one of claims 1 to 8, wherein the absorber is arranged away from the nozzle surface at the minute open position. With the wiper
A wiping mechanism that supports the wiper and brings the wiper into contact with the nozzle surface or separates it from the nozzle surface.
With
The inkjet according to any one of claims 1 to 9, wherein the control device is configured to perform a wiping process of wiping the nozzle surface by the wiper after at least the micro open position process. Printer. The nozzle surface of the ink head includes another nozzle that ejects another ink different from the ink.
The inkjet printer according to any one of claims 1 to 10, wherein the cap can be attached to the nozzle surface so as to cover the nozzle and the other nozzle. Ink tank where ink is stored and
An ink supply path that connects the ink tank and the nozzle,
A pressure detection mechanism that detects the pressure in the ink supply path, and
With
The control device is configured to execute the minute open position determination process for determining the minute open position.
For the minute open position determination process,
In a state where the cap is attached to the nozzle surface, a separation movement process of moving the cap in a direction in which the cap is separated from the nozzle surface, and a separation movement process.
While the separation movement process is being executed, the separation detection pressure, which is the pressure in the ink supply path, is detected, and the separation pressure determination process for determining whether or not the separation detection pressure is larger than a predetermined determination pressure,
A position storage process for storing the position of the cap with respect to the nozzle surface in the storage device as the minute open position when the separation detection pressure is first determined to be larger than the determination pressure in the separation pressure determination process.
The inkjet printer according to any one of claims 1 to 11. For the minute open position determination process,
In the state where the cap is not attached to the nozzle surface, the approaching movement process of moving the cap in the direction in which the cap is attached to the nozzle surface, and
While the approach movement process is being executed, the approach pressure determination process that detects the approach detection pressure, which is the pressure in the ink supply path, and determines whether or not the approach detection pressure is equal to or less than the determination pressure,
Is included,
In the separation movement process, when the approach detection pressure is first determined to be equal to or lower than the determination pressure in the approach pressure determination process, the cap is moved in a direction in which the cap is separated from the nozzle surface. The inkjet printer according to claim 12. With a damper arranged in the ink supply path,
The damper is
A storage chamber having an opening partially formed and communicating with the ink supply path,
A damper membrane covering the opening of the storage chamber and
With
The inkjet printer according to claim 12 or 13, wherein the pressure detecting mechanism detects the pressure in the storage chamber. The damper is
The pressing body provided on the damper film and
A filler provided on the side opposite to the storage chamber with respect to the damper membrane and whose position is changed as the pressing body moves.
Have,
The pressure detection mechanism detects whether or not the filler has moved within a predetermined range, and when the filler is not located within the predetermined range, the pressure in the storage chamber is larger than the determination pressure. It is a filler sensor configured to detect that
In the separation pressure determination process, the filler sensor determines whether or not the filler is located within the predetermined range.
In the position storage process, the position of the cap with respect to the nozzle surface when it is first determined in the separation pressure determination process that the filler is not located within the predetermined range is stored as the minute open position. The inkjet printer according to claim 14, which is stored in an apparatus. An ink head having a nozzle surface with a nozzle for ejecting ink,
A cap that can be mounted on the nozzle surface so as to cover the nozzle and has an end that can come into contact with the nozzle surface when mounted on the nozzle surface, a suction device connected to the cap, and the above. A cap unit having a capping mechanism for attaching or separating the cap from the nozzle surface,
The suction position, which is the position of the cap when the end of the cap is in contact with the nozzle surface and the ink in the nozzle is sucked by the suction device, and the end of the cap are said. It is located away from the nozzle surface and at the air suction position, which is the position of the cap when the ink in the nozzle is not sucked by the suction device, and between the suction position and the air suction position. A storage device that stores the minute open position in advance,
Control device and
With
The control device
With the cap placed at the suction position, a suction process that sucks ink from the nozzle and
After the suction process, a moving process of moving the cap toward the minute open position and a moving process.
After the movement processing, the movement of the cap is stopped and the suction device is stopped in a state where the cap is arranged at the minute opening position.
An inkjet printer configured to run. A computer program for cleaning in the inkjet printer according to any one of claims 1 to 16, for at least a computer to realize the suction process, the move process, and the minute open position process.

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