JP2007111932A - Liquid jetting apparatus and its maintenance method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jetting apparatus which can effectively suppress the generation of mist that becomes minute droplets to float when maintenance is carried out. <P>SOLUTION: The liquid jetting apparatus and its maintenance method are constituted by providing a platen 13 that supports paper P, a recording head 23 that jets ink from nozzles to the paper P, a carriage 20 that reciprocates the recording head 23 in the main scanning direction at a predetermined height position to the platen 13, a flushing control means 49 that recovers jetting characteristics of the recording head 23 by jetting the ink from the nozzles to a flushing box 15 provided in a flushing region outside a printing region where the paper P is supported by the platen 13, and a head position changing means 10 that changes a height position of the recording head 23 to the platen 13. In this case, the flushing control means 49 controls so that the height position of the recording head 23 becomes lower than the height position of the recording head 23 during the printing operation to the paper P when the flushing operation is carried out. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  According to the present invention, in a liquid ejecting apparatus used as an ink jet recording apparatus that forms dots on a recording medium by ejecting ink droplets from nozzles corresponding to printing data, droplets unrelated to printing or the like are ejected from the nozzles. The present invention relates to a liquid ejecting apparatus that recovers the droplet discharge capability of a nozzle and a maintenance method thereof.

  As liquid ejecting apparatuses that eject liquid as droplets from nozzles, those that target various liquids are known, and among them, an ink jet recording apparatus can be given as a typical example.

  Such a recording head generally includes a plurality of nozzles, a pressure chamber communicating with each nozzle, and a pressure generating element that generates pressure in the pressure chamber. The pressure generating element is driven in response to the print signal to vary the pressure in the pressure chamber, and the ink in the pressure chamber is ejected from the nozzles as ink droplets due to the pressure variation. In an apparatus that performs color printing, not only black but also various types of color ink such as yellow (yellow), magenta (red purple), and cyan (blue green) are used as the ink. Nozzles are determined for each color. Is provided.

  In the recording head as described above, nozzles that frequently eject ink droplets during printing operations are supplied with new ink one after another, so that clogging hardly occurs. In the case of nozzles that have very few opportunities to occur, ink near the nozzles dries and thickens during printing, which tends to cause clogging.

  In order to deal with such problems, the pressure generating element is driven independently of printing, and ink drops are forcibly ejected from each nozzle to eliminate nozzle clogging and restore the ink drop ejection capability. "Flushing operation" is executed. Such a flushing operation is performed at predetermined time intervals during the continuation of the printing operation, and the ejection capability of the nozzle in which the ejection capability of the ink droplet has decreased during the printing operation is recovered.

In the flushing operation, the recording head that reciprocates in the width direction of the recording paper is moved to the flushing area outside the printing area, and ink droplets that are not related to printing are directed toward the flushing box provided in the flushing area. Is ejected to discharge the thickened ink in the vicinity of the nozzle opening to restore the ejection capability of the nozzle.
JP 2000-153621

  In recent years, in order to enable printing on a recording medium that is thicker than plain paper, such as CD-R or thick paper, a recording apparatus that can change the height dimension of the recording head relative to the platen that supports the recording paper is available. Is provided. In such a recording apparatus, when printing on relatively thin recording paper such as plain paper, the height position of the recording head with respect to the platen is set low to eject ink droplets, and relatively thick such as thick paper. When printing on recording paper, by setting the height position of the recording head relative to the platen high and ejecting ink droplets, there is little change in the gap between the recording paper surface and the nozzle surface of the recording head during recording. To record.

  However, when the height position of the recording head with respect to the platen is increased in this way, the distance between the flushing box and the nozzle surface of the recording head is greatly increased during the flushing operation. When the distance from the nozzle surface to the landing surface during flushing is increased, the ink droplets ejected by the flushing operation float as mist due to air resistance before landing on the flushing box, causing contamination of the surroundings. To do.

  Also, the ink droplets ejected from the nozzle openings are charged a little, and are also affected by the static electricity generated by the drive unit in the recording device and the air flow by the exhaust fan arranged to suppress the temperature rise in the device. There is also a problem that it is accelerated and contaminates the surroundings (outside) where the recording apparatus is arranged. In particular, in recent printing apparatuses in which the amount of each ink droplet is controlled to be as small as possible in order to realize high image quality, such a problem appears more conspicuously.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a liquid ejecting apparatus and a maintenance method thereof that can effectively suppress the generation of mist that floats as fine droplets during a maintenance operation. .

  In order to achieve the above object, a liquid ejecting apparatus of the present invention includes a platen that supports an ejected object, an ejecting head that ejects liquid from a nozzle to the ejected object, and a predetermined height position relative to the platen. By ejecting liquid from a nozzle to a carriage that reciprocates the ejection head in the main scanning direction and a maintenance landing portion provided in a maintenance area outside the ejection area where an object to be ejected is supported by the platen, Maintenance control means for recovering the ejection characteristics, head position changing means for changing the height position of the ejection head with respect to the platen, and ejection from the height position of the ejection head during the ejection operation to the ejection object during the maintenance operation The gist of the invention is that it includes position control means for controlling the height position of the head to be lowered.

  In order to achieve the above object, a maintenance method for a liquid ejecting apparatus according to the present invention includes a platen that supports an ejected object, an ejecting head that ejects liquid from the nozzle to the ejected object, and a predetermined height with respect to the platen. By ejecting liquid from the nozzle to a carriage that reciprocates the ejection head in the main scanning direction at the vertical position and a maintenance landing portion provided in a maintenance area outside the ejection area where the ejection target is supported by the platen A maintenance method for a liquid ejecting apparatus comprising maintenance control means for recovering ejection characteristics of an ejection head and head position changing means for changing the height position of the ejection head with respect to the platen, wherein the ejection object is in a maintenance operation The height position of the ejection head is set to be lower than the height position of the ejection head during the ejection operation. And it is required to.

  Since the present invention controls the height position of the ejection head to be lower than the height position of the ejection head during the ejection operation to the ejection object during the maintenance operation, for example, the thickness of the ejection object changes. Even if the height position of the ejection head with respect to the platen is changed accordingly, the height position is lowered during maintenance and the ejection head is brought closer to the maintenance landing part to eject the liquid. Will surely land on the maintenance landing part, drastically reduce the droplets floating as mist and prevent the surrounding pollution. In particular, the influence of static electricity on the charged droplets and the influence of the air flow of the exhaust fan can be minimized, and mist can be effectively suppressed even in modern devices that control droplets to be small. It becomes. As described above, since maintenance that effectively suppresses mist becomes possible, it is possible to perform maintenance that reliably restores the ejection capacity by ejecting minute droplets compared to the conventional case, and saves liquid consumed for maintenance. In addition, the storage space for the liquid used for maintenance is small, which is advantageous for downsizing the device.

  In the present invention, when the position control means controls to lower the height position of the ejection head during the maintenance operation corresponding to the height position of the ejection head during the ejection operation to the ejection object. Since the maintenance operation can be performed by always setting the gap dimension between the ejection head and the maintenance landing part at the time of the maintenance operation to be optimal, the mist can always be effectively suppressed and the surrounding contamination can be prevented.

  In the present invention, the maintenance operation is executed at a predetermined time interval during the injection operation to the injection target, and the position control means controls to lower the height position of the injection head every time the maintenance operation is performed. Since the maintenance operation can be performed by always setting the gap dimension between the ejection head and the maintenance landing part at the time of the maintenance operation to be optimal, the mist can always be effectively suppressed and the surrounding contamination can be prevented.

  In the present invention, the maintenance landing portion is disposed at a position where the distance between the ejection head and the maintenance landing portion is the most suitable distance for maintenance in a state where the height position of the ejection head is set to the lowest position. If the jet head is jetted to a thin jet object or jetting with high quality such as jet resolution, jetting is performed with the jet head set at the lowest position. In this case, it is possible to perform the maintenance operation while maintaining the height position of the ejection head.

  In the present invention, when performing the ejection operation on the ejection object in a state where the height position of the ejection head is set to a position higher than the lowest position by the head position changing means, the position control means performs the ejection operation every time the maintenance operation is performed. When controlling the head to be lowered, the maintenance operation can be performed with the gap dimension between the ejection head and the maintenance landing part always optimized every time the maintenance operation is performed. It is possible to prevent the surrounding contamination by suppressing.

  In the present invention, the maintenance landing portion is provided on the home position side of the carriage movement range, and the position control means lowers the height position of the ejection head every time a maintenance operation is performed on the maintenance landing portion on the home position side. In the case of such control, it is possible to effectively suppress mist at the maintenance landing portion on the home position side and prevent surrounding contamination. In this case, by disposing the capping means having the waste liquid flow path and the maintenance landing portion on the same side, it becomes easy to dispose the waste liquid tank and route the waste liquid flow path, and the degree of freedom of design is increased.

  In the present invention, the maintenance landing part is provided at both ends of the carriage movement range, and the position control means controls to lower the height position of the ejection head at every maintenance operation at both maintenance landing parts. For example, in a large-sized ejection device that must reliably recover the droplet ejection capability for each scan of the carriage reciprocating movement, the mist floats at the maintenance landing portions provided on both sides of the carriage movement range. Since it can be prevented, the effect of suppressing surrounding contamination is remarkable and effective.

  In the present invention, when the maintenance landing part is provided separately from the capping unit of the ejection head, without considering the sealing characteristics of the nozzle surface or the deterioration characteristics of the cap like the capping unit, The height position of the maintenance landing part can be set so that the distance between the maintenance landing part and the ejection head can be optimized considering only the suppression of mist during maintenance. Can prevent contamination.

  In the following description, in the liquid droplet ejection direction, the surface far from the platen is referred to as the upper side and the side closer to the platen is described as the lower side with reference to the surface of the platen facing the recording head. Therefore, in the present invention, the height position is a height position based on the surface of the platen facing the recording head. However, this is not intended to limit the droplet ejection direction to the vertical direction, but also to include those in which the droplet ejection direction is oblique or lateral.

  Next, embodiments of the present invention will be described in detail.

(First embodiment)
1 to 7 show a first embodiment in which the present invention is applied to a printer which is an ink jet recording apparatus.

  FIG. 1 is a perspective view illustrating an example of a printer 11 as a liquid ejecting apparatus of the present invention, and FIG. 2 is a front view illustrating a main part of the printer 11.

  The printer 11 has a frame 12. A platen 13 extending in the X direction is installed on the frame 12. The platen 13 is a support base that supports the paper P as an injection target. Further, the printer 11 has a paper feed mechanism having a paper feed motor 14. The paper feed motor 14 drives a driving roller (not shown) to convey the paper P in the Y direction which is the sub-scanning direction (from the back side to the front side of the printer 11), and guides the paper onto the platen 13. Yes.

  A driving pulley 16 and a driven pulley 17 are fixed to the frame 12. The drive pulley 16 is connected to a carriage motor 18. A timing belt 19 is hung on the pair of pulleys 16 and 17, and a carriage 20 is fixed to the timing belt 19.

  The carriage 20 has two ink cartridges 21 and 22 detachably mounted thereon. The ink cartridge 21 contains black ink. The ink cartridge 22 stores magenta, cyan, and yellow inks (color inks) in three storage chambers. The carriage 20 has a recording head 23 as an ejection head on the lower surface, and the nozzle surface of the recording head 23 faces the platen 13. The recording head 23 includes a plurality of nozzles (not shown) opened on the lower surface. Each nozzle is provided with a corresponding piezoelectric element (not shown). When this piezoelectric element is driven, ink is supplied from the ink cartridges 21 and 22 to the recording head 23, and the nozzle discharges. Ink that is liquid is ejected from the outlet toward the paper P on the platen 13.

  On the other hand, the carriage 20 is formed with a support hole 20a penetrating in the X direction. A guide member 25 as a support shaft is inserted through the support hole 20a. Accordingly, the carriage 20 can be reciprocated in the X direction via the timing belt 19 by being driven by the carriage motor 18 while being guided by the guide member 25, and the recording head at a predetermined height position with respect to the platen 13. 23 is reciprocated in the X direction which is the main scanning direction.

  Next, the head position changing unit 10 that raises and lowers the carriage 20 to change the height position of the recording head 23 with respect to the platen 13 will be described.

  FIG. 3A shows a state where the carriage 20 is at the lowest position, and FIG. 3B shows a state where the carriage 20 is raised from the lowest position.

  The head position changing means 10 includes a middle shaft 26, an eccentric shaft 27, an operating lever 28, an operation member 29, and a lifting rod 54. The middle shaft 26 is a pivotable shaft built in the guide member 25 as shown in FIG. An eccentric shaft 27 eccentric to the center of the shaft is integrally fixed to both ends of the middle shaft 26. Each eccentric shaft 27 is rotatably supported by the frame 12. The right eccentric shaft 27 is fixed to an operating lever 28.

  An operating groove 28 a is formed in the operating lever 28. The operation member 29 is pivotally supported by the frame 12 so that the center portion 29c can rotate. A slider 29 a extending from the central portion 29 c of the operation member 29 toward the guide member 25 is slidably and rotatably connected to the operating groove 28 a of the operating lever 28. The operation portion extending forward from the central portion 29c is pivotally supported by a slider 29a provided in the vicinity of the upper end of the elevating rod 54 whose tip portion extends in the vertical direction. The elevating rod 54 can be moved up and down in the longitudinal direction by an elevating mechanism (not shown) (for example, rack-on-pinion) provided in the gear box 55 (see FIG. 1).

  Then, when the elevating rod 54 moves up and down in the r direction at a predetermined timing, the operation member 29 rotates and the operation lever 28 rotates. As a result, the eccentric shaft 27 rotates, and the middle shaft 26 fixed to the eccentric shaft 27 rotates and moves up and down. As a result, the carriage 20 moves up and down, and the gap between the platen 13 and the recording head 23 is changed. The height position of 23 is changed.

  As shown in FIG. 3A, when the carriage 20 is at the lowest position, the height position of the recording head 23 with respect to the platen 13 is the lowest, and the upper surface of the platen 13 and the nozzle surface of the recording head 23 at this time are the same. The distance PG1 is set to be the smallest. At this time, the height position of the central shaft 26, that is, the carriage 20 and the recording head 23, with respect to the upper surface of the platen 13, is H1.

  As shown in FIG. 3B, when the carriage 20 is raised from the lowest position, the height position of the recording head 23 with respect to the platen 13 is increased, and the upper surface of the platen 13 and the nozzle surface of the recording head 23 at this time The distance PG2 is set to be large. At this time, the height position of the center shaft 26, that is, the carriage 20 and the recording head 23, with respect to the upper surface of the platen 13, is H2.

  Thus, the height position of the recording head 23 changes from H1 to H2 by the operation of the head position changing means 10. The difference in height at that time is indicated by H in the figure.

  On the other hand, a cleaning device for protecting and cleaning the nozzles of the recording head 23 is located near the end of the moving range of the carriage 20, which is a non-printable area on one side of the frame 12, (home position; right side in the figure). 30 is provided.

  The cleaning device 30 accommodates a drive motor, a cylindrical cam, and a tube pump (not shown) in a rectangular parallelepiped box case 31, and a capping device 34 and a wiping device 35 are provided near the upper opening of the case 31. Yes. The upper part of the cylindrical cam, the tube pump, and the drive motor in the case 31 is closed by a lid and cannot be seen in the figure.

  The drive motor is a reversible motor, and generates a driving force by rotating in the forward and reverse directions and is transmitted to a cylindrical cam, a capping device 34, a wiping device 35, and a tube pump through a gear (not shown). Thereby, the cylindrical cam, the capping device 34, the wiping device 35, and the tube pump are driven.

  On the other hand, the capping device 34 provided on the upper portion of the case 31 includes a cap 56 and a cap support member that supports the cap 56. The cap 56 is a box having an upper opening, and the opening is sized to cover the nozzles of the recording head 23.

  A close contact portion made of an elastic material is provided at the periphery of the opening of the cap 56, and the cap 56 is airtight when the cap 56 covers the nozzles of the recording head 23. Further, a sheet-like absorber is provided on the inner bottom portion of the cap 56. When the cap covers the nozzle, ink is held in the absorber to keep the humidity in the cap 56 high, and the nozzle of the recording head 23 Prevents ink from drying inside. Further, an ink discharge port for discharging the ink in the cap is provided on the bottom surface of the cap 56, and when the tube pump is driven, the ink discharge port discharges high-viscosity ink, dust, bubbles, etc. from the nozzle of the recording head 23. Aspirate and discharge. Further, a waste liquid pipe 39 connected to the waste liquid tank 24 communicates with the ink discharge port, and the sucked ink is introduced into the waste liquid tank 24.

  On the other hand, the wiping device 35 includes a wiping member made of a substantially rectangular parallelepiped elastic material. The wiping member protrudes from the lower surface of the recording head 23. For this reason, when the recording head 23 crosses over the wiping device 35, the wiping member is pushed and bent by the recording head 23, slidably contacts the lower surface of the recording head 23, and wipes and cleans the nozzles of the recording head 23.

  In the printer 11, a flushing box 15 as a maintenance landing portion provided separately from the capping device 34 of the recording head 23 is provided in a maintenance area outside the ejection area where the paper P that is an ejection target is supported by the platen 13. Is provided. The flushing box 15 is provided at a position adjacent to the cleaning device 30, that is, on the capping means side (home position side) of the movement range of the carriage 20.

  The flushing operation as a maintenance operation restores the ejection characteristics of the nozzle by a flushing operation in which the piezoelectric element is driven and ejects ink from the nozzle at a predetermined time interval during printing, regardless of the print signal. The flushing box 15 receives ink ejected by the flushing operation, is formed in a square dish shape slightly larger than the nozzle surface of the recording head 23, and a sheet-like absorber that absorbs ink on the ink receiving surface. Is provided to reliably catch the ink droplets ejected by flushing and prevent rebound and re-scattering. Further, the flushing box 15 communicates with a waste liquid pipe 40 connected to the waste liquid tank 24 to introduce the sucked ink into the waste liquid tank 24.

  In the flushing box 15, the carriage 20 is moved in the X direction with the head position changing means 10 set to the position where the height of the recording head 23 is the lowest (that is, the nozzle surface is closest to the platen 13). When the recording head 23 and the flushing box 15 face each other, the nozzle surface of the recording head 23 and the flushing box 15 are arranged and fixed at a position that is the most suitable distance for flushing. The height position of the recording head 23 at this time is the optimum platen 13 and nozzle surface when assuming the thinnest paper P among the papers P targeted by the printer 11 or assuming the printing with the highest image quality. It corresponds to the distance.

  In this printer 11, when printing on thick paper P such as thick paper, the head position changing means 10 sets the height position of the recording head 23 to a position H2 higher than the lowest position H1 and prints. Is done. As described above, when printing is performed at the position H2 where the recording head 23 is higher than the lowest position H1, the carriage 20 moves in the X direction during the flushing operation performed at predetermined time intervals during the printing operation. When the recording head 23 and the flushing box 15 face each other, the head position changing unit 10 causes the recording head to be higher than the height position of the recording head 23 during the printing operation as the ejection operation on the paper P that is the ejection target. Control is performed so that the height position of 23 is lowered, and flushing discharge is performed in this state. The flushing operation is performed at a predetermined time interval during the printing operation on the paper P, and the flushing control means 49 as a position control means described later lowers the height position of the recording head 23 every time the flushing operation is performed. Control to do.

  FIG. 4 is a block diagram showing the system configuration of the printer.

  In the figure, a host computer 44 has a built-in printer driver 45. The size of the paper P, monochrome / color printing selection, and recording mode are input by an input device (not shown) on the utility of the printer driver 45. Selection, font data, and print commands can be input.

  In response to the input of the print command, the printer driver 45 sends print data that is liquid ejection data to the print control means 46. Further, the print control means 46 generates bitmap data based on the print data, generates a drive signal by the head drive means 48 and inputs it to the piezoelectric vibrator, and ejects ink droplets from the recording head 23. Yes.

  The head driving means 28 functions as a driving means, and receives a flushing command signal from a flushing control means 49 as a maintenance control means in addition to a drive signal based on print data, and records a driving signal for flushing. Output to the head 23. The flushing control means 49 executes a flushing operation and ejects ink unrelated to printing from the nozzles to the flushing box 15, thereby discharging the thickened ink near the nozzles and improving the ejection characteristics of the recording head 23. Recover.

  Here, the mechanism by which the discharge capacity of the nozzles is reduced during printing will be described. During the printing, the nozzle surface of the recording head 23 is released from the cap 56 and is moved back and forth by the carriage 20. If the ink is not ejected in such a state, the solvent evaporates from the ink present in the nozzle opening, the viscosity gradually increases, and the ejection capacity decreases. Further, nozzles that frequently eject ink droplets during printing are supplied with new ink one after another, and clogging does not occur so much, but nozzles that have few opportunities to eject ink droplets tend to clog. Therefore, as the nozzle discharge amount is small and the idle time is long, the thickening proceeds, and the degree thereof varies from nozzle to nozzle.

  In this example, the case has been described in which the liquid ejected by the ejection head is ink, and the ejection capability of the nozzle is reduced due to the increased viscosity of the ink. However, the mechanism by which the ejection characteristics are degraded varies depending on the type of liquid to be ejected. In some cases, the present invention is applicable not only to ink but also to an apparatus that ejects various liquids as long as the lowered nozzle ejection characteristics can be recovered by liquid ejection.

  The carriage control means 47 performs movement control for reciprocating the carriage 20 in the main scanning direction during the printing operation, and also moves the carriage to a flushing position other than the printing area at a predetermined flushing timing, thereby moving the recording head 23 to the flushing box 15. The movement control is performed so as to move to a position where the flushing operation is performed while facing each other. Further, the carriage control means 47 performs movement control for moving the recording head 23 to the position of the capping device 34 when the apparatus is powered off or when a cleaning operation is performed.

  In this recording apparatus, the flushing control means 49 also functions as the position control means of the present invention, and the position sensor 43 determines the height position of the recording head 23 during the printing operation on the paper P that is the ejection target. In response to the detected height position of the recording head 23, the lifting rod 54 in the head position changing means 10 is driven to control the height position of the recording head 23 to be lowered during the flushing operation.

  Further, the head position changing unit 10 allows the thickness of the paper P to be set to the initial setting value when the user inputs the setting of the thickness of the paper P in the printer driver 45 when printing on the relatively thick paper P. The height mechanism of the recording head 23 can be changed by operating the lifting mechanism by the increased amount.

  FIG. 5 is a flowchart showing the flushing operation.

  As shown in FIG. 6, first, when printing on a relatively thin paper P, the user inputs a setting of the thickness of the paper P in the printer driver 45, whereby the head position changing means 10 causes the platen 13 to be changed. The height of the recording head 23 is lowered (H1), the recording head 23 is at the lowest position, and the gap between the platen 13 and the recording head 23 is the smallest gap PG1. As described above, the height of the flushing box 15 is set in accordance with the position of the nozzle surface of the recording head 23 at the lowest position (H1). The distance L is set to an optimum interval for the flushing operation.

  In this state, the printer 11 drives the paper feed motor 14, and when the paper P is introduced between the platen 13 and the recording head 23, ink is ejected from the nozzles of the recording head 23 onto the paper P. And print. The flushing operation is executed at predetermined time intervals during the printing operation on the paper P. When the flushing operation starts, the flushing control means 49 moves the carriage 20 to the flushing position (S1).

  Next, the flushing control means 49 determines whether the height position of the recording head 23 during the printing operation is higher or lower than the lowest position, which is an initial setting value (S2). At this time, the height position of the recording head 23 during the printing operation can be detected by the position sensor 43, or the setting information in the printer driver 45 can be read and used.

  In this state, the recording head 23 is set to the lowest position (H1), and the distance L between the nozzle surface and the flushing box 15 is the optimum distance in the height position of the flushing box 15 (No in S2). ), Flushing discharge is executed in a state where the height position H1 of the recording head 23 is maintained (S3), the flushing operation is completed, the carriage 20 is returned to the printing area again, and the printing operation is resumed.

  At this time, since the distance between the recording head 23 and the flushing box 15 is the optimum distance L at the time of flushing, the ink droplets ejected by the flushing operation surely land on the flushing box 15 and float as mist. The ink droplets to be drastically reduced and surrounding contamination is prevented.

  As shown in FIG. 7, when printing is performed on a relatively thick paper P, for example, when the user inputs the setting of the thickness of the paper P in the printer driver 45, the thickness of the paper P is set to the initial setting value. The raising / lowering mechanism of the position switching means 10 is operated by the increased amount to change the position of the recording head 23 from the position shown in FIG. 3A to the position shown in FIG. At this time, the operating member 29 and the operating lever 28 are rotated, and the eccentric shaft 27 fixed to the frame 12 rotates clockwise in FIG. Then, since the middle shaft 26 fixed to the eccentric shaft 27 rotates and moves up and down as shown in FIG. 3B, the guide member 25 is moved up and down, and the recording head 23 of the carriage 20 is moved by the height H. As shown in FIG. 3, the gap between the platen 13 and the recording head 23 becomes a gap PG2 that is higher than the gap PG1 by the height H. At this time, since the rotating central shaft 26 is rotatable with respect to the guide member 25, the carriage 20 moves up without changing its posture.

  In this way, the height position of the recording head 23 with respect to the platen 13 is raised (H2), and the distance D between the nozzle surface of the recording head 23 and the surface of the paper P at the time of printing is set to be the same as that of the thin paper P. To be done. In this state, the printer 11 drives the paper feed motor 14, and when the paper P is introduced between the platen 13 and the recording head 23, ink is ejected from the nozzles of the recording head 23 onto the paper P. And print.

  When the flushing operation starts, the flushing control means 49 moves the carriage 20 to the flushing position (S1). Next, the flushing control means 49 determines whether the height position of the recording head 23 during the printing operation is higher or lower than the lowest position, which is an initial setting value (S2). At this time, since the height position of the recording head 23 during the printing operation is a position (H2) higher than the lowest position, which is an initial setting value (Yes in S2), the flushing control means 49 adjusts the head position accordingly. The position changing means 10 is operated to lower the position of the recording head 23 to the lowest position (H1) (S4), and flushing injection is performed (S5). At the time of this flushing, since the distance between the recording head 23 and the flushing box 15 is the optimum distance L, the ink droplets ejected by the flushing operation surely land on the flushing box 15 and float as mist. Drops are greatly reduced and ambient contamination is prevented.

  When the flushing injection is finished, the flushing control means 49 operates the head position changing means 10 to return the recording head 23 to the height position (H2) during printing (S6), the flushing operation is finished, and the carriage 20 is moved again. Return to the print area and resume printing. As described above, the flushing control means 49 is such that the gap dimension L between the recording head 23 and the flushing box 15 during the flushing operation is substantially independent of the height position of the recording head 23 during the printing operation on the paper P. Is set to be constant.

  The flushing operation is performed at a predetermined time interval during the printing operation on the paper P. At this time, the flushing control means 49 controls to execute the operation of lowering the height position of the recording head 23 (S4 to S6) every time the flushing operation is performed. Each time the flushing operation is performed, the distance L between the flushing box 15 and the nozzle surface becomes an optimum interval.

  After that, when printing a relatively thin paper P again, the user inputs the setting of the thickness of the paper P in the printer driver 45, and the height position of the recording head 23 is shown in FIG. From the position, the position is as shown in FIG. As a result, the guide member 25 is lowered, the carriage 20 is lowered, and the gap between the platen 13 and the recording head 23 is changed from the gap PG2 to the gap PG1.

  According to the printer 11 of the present embodiment, the following effects can be obtained.

  The printer 11 of the above embodiment controls the height position of the recording head 23 to be lower than the height position of the recording head 23 during the printing operation on the paper P during the flushing operation. Even if the height position of the recording head 23 relative to the platen 13 is changed accordingly, the height position of the flushing box 15 is changed corresponding to the height position, and the ink droplets ejected by the flushing operation are changed. Reliably land on the flushing box 15 and drastically reduce ink droplets floating as mist, thereby preventing contamination of the surroundings. In particular, the effect of static electricity on charged ink droplets and the influence of the air flow of the exhaust fan can be minimized, and mist can be effectively suppressed even in modern devices that control ink droplets to a small size. It becomes. As described above, since maintenance that effectively suppresses mist becomes possible, it is possible to perform maintenance that reliably restores the ejection capacity by ejecting minute droplets compared to the conventional case, and saves liquid consumed for maintenance. In addition, the storage space for the liquid used for maintenance is small, which is advantageous for downsizing the device.

  In the printer 11 of the above embodiment, the flushing control means 49 lowers the height position of the recording head 23 during the flushing operation corresponding to the height position of the recording head 23 during the printing operation on the paper P. Therefore, the flushing operation can be performed by always setting the gap dimension between the recording head 23 and the flushing box 15 at the time of the flushing operation to be optimal, so that the mist is always effectively suppressed and the surrounding contamination is prevented. Can be prevented.

  In the printer 11 of the above embodiment, the flushing operation is executed at predetermined time intervals during the printing operation on the paper P, and the flushing control means 49 lowers the height position of the recording head 23 every time the flushing operation is performed. Therefore, the flushing operation can be performed by always setting the gap dimension between the recording head 23 and the flushing box 15 at the time of the flushing operation to be optimal, so that the mist is always effectively suppressed and the surrounding contamination is prevented. Can be prevented.

  In the printer 11 of the above embodiment, the flushing box 15 is set at the position where the height of the recording head 23 is the lowest, and the distance between the recording head 23 and the flushing box 15 is the most suitable for flushing. The height of the recording head 23 is set to the lowest position, such as when jetting on thin paper or when jetting with high quality such as printing resolution. When jetting, the flushing operation can be performed in a state where the height position of the recording head 23 is maintained.

  When the printer 11 of the above embodiment performs a printing operation on the paper P in a state where the head position changing unit 10 sets the height position of the recording head 23 to a position higher than the lowest position, the flushing control unit 49 is Since the control is performed so that the height position of the recording head 23 is lowered every time the flushing operation is performed, the flushing operation can be performed by always optimizing the gap size between the recording head 23 and the flushing box 15 every time the flushing operation is performed. , Can always effectively suppress mist and prevent surrounding pollution.

  In the printer 11 of the above embodiment, the flushing box 15 is provided on the home position side of the moving range of the carriage 20, and the flushing control means 49 performs the recording head 23 every time the flushing operation is performed in the flushing box 15 on the home position side. Therefore, the mist is effectively suppressed in the flushing box 15 on the home position side, so that surrounding contamination can be prevented. In this case, by disposing the capping device 34 having the waste liquid flow path and the flushing box 15 on the same side, it is easy to dispose the waste liquid tank 24 and route the waste liquid pipes 39 and 40, and the degree of freedom of design is increased.

  In the printer 11 of the above embodiment, since the flushing box 15 is provided separately from the capping device 34 of the recording head 23, the sealing characteristics of the nozzle surface, the deterioration characteristics of the cap 56, etc., as in the capping device 34, are provided. Without considering it, it is possible to set the height position of the flushing box 15 so that the distance between the flushing box 15 and the recording head 23 is optimized considering only suppression of mist during flushing. Mist can be suppressed and surrounding pollution can be prevented.

(Second Embodiment)
FIG. 8 shows a second embodiment of the liquid ejecting apparatus to which the present invention is applied.

  In this embodiment, flushing boxes 15 as maintenance landing portions are provided at both ends of the movement range of the carriage 20. The flushing control means 49 controls to lower the height position of the recording head 23 every time the flushing operation is performed in the two flushing boxes 15. Other than that, it is the same as that of the said 1st Embodiment, the same code | symbol was attached | subjected to the same part, and the detailed description was abbreviate | omitted.

  According to this embodiment, for example, in a large-sized ejection device that must reliably recover the ink droplet ejection performance for each scan of the carriage 20 that reciprocates, flushing provided on both sides of the movement range of the carriage 20. Since the box 15 can prevent the mist from floating, the effect of suppressing the surrounding contamination is remarkable and effective. Other than that, there exists an effect similar to the said 1st Embodiment.

  In addition, this invention is not limited to said each embodiment, It is the meaning including the following modifications.

  The cap raising / lowering means for raising and lowering the cap 56 of the capping device 34 may be a mechanism that moves both in the vertical direction and in the horizontal direction, that is, a configuration that moves up and down obliquely as in the conventional art.

  The transmission means for transmitting the driving force of the head position changing means 10 to the cleaning device 30 may be a mechanism other than the attachment member shown in the above embodiments. For example, the cleaning device 30 may be moved up and down by using a link mechanism as the transmission means.

  The raising / lowering means for raising and lowering the guide member 25 may be a mechanism other than that shown in the above embodiment. For example, in the first and second embodiments, elevating means may be provided at both ends of the guide member 25, and the elevating means may be moved up and down by the elevating means.

  The head position changing means 10 may be configured such that the user can change the height position of the recording head 23 by manually operating the operation lever 28 according to the thickness of the paper P.

  In each of the above embodiments, the flushing injection is performed on the flushing box 15 provided separately from the capping device 34. However, the capping device 34 is also used as the flushing box 15 and the flushing jet is performed on the cap 56. You may do it.

  In each of the embodiments described above, the recording head 23 can be applied to a liquid ejecting apparatus that uses a piezoelectric vibrator as a pressure generating element that is a driving element that ejects liquid, or a liquid ejecting type that uses a heating element. It can also be applied to a device.

  In addition, a program for causing a computer device to execute the maintenance method of the present invention can be provided by being recorded on a recording medium or can be provided via a communication network.

  In addition, as a typical example of the liquid ejecting apparatus, there is an ink jet recording apparatus provided with the above-described ink jet recording head for image recording. However, the present invention is an example of another liquid ejecting apparatus such as a liquid crystal display. Device with color material ejection head used for color filter production, device with electrode material (conductive paste) ejection head used for electrode formation such as organic EL display, surface emitting display (FED), etc., used for biochip production The present invention can be applied to various liquid ejecting apparatuses such as an apparatus having a biological organic matter ejecting head and an apparatus having a sample ejecting head as a precision pipette.

1 is a perspective view illustrating an example of a printer according to an embodiment to which the present invention is applied. It is a front view which shows the principal part of the said printer. FIG. 3 is a conceptual side view showing a positional relationship between a head position changing unit and a recording head. FIG. 2 is a functional block diagram illustrating a system configuration of the printer. It is a flowchart which shows flushing operation | movement. It is a figure explaining the effect | action of the said printer. It is a figure explaining the effect | action of the said printer. It is a front view which shows the principal part of the printer in 2nd Embodiment.

Explanation of symbols

10 Head position changing means, 11 Printer, 12 Frame, 13 Platen, 14 Paper feed motor, 15 Flushing box, 16 Drive pulley, 17 Pulley, 18 Carriage motor, 19 Timing belt, 20 Carriage, 20a Support hole, 21 Ink cartridge, 22 Ink cartridge, 23 Recording head, 24 Waste liquid tank, 25 Guide member, 26 Center shaft, 27 Eccentric shaft, 28 Actuation lever, 28a Actuation groove, 29 Operation member, 29a Slider, 29c Central part, 30 Cleaning device, 31 Case , 32 Lifting member, 33 Cylindrical cam, 34 Capping device, 35 Wiping device, 36 Gear part, 37 Cam slit, 37a Upper horizontal part, 37b Lower horizontal part, 37c Inclined part, 38 Fitting projection, 39 Waste pipe, 40 Waste pipe, 41 Bracket, 42 Insertion hole, 43 Position sensor, 44 Host computer, 45 Printer driver, 46 Print control means, 47 Carriage control means, 48 Head drive means, 49 Flushing control means, 50 Mounting piece, 51 Vertical piece, 52 Guide piece, 53 Slit, 54 Lifting rod, 54a Slider, 55 Gear box, 56 Cap

Claims (8)

  A platen that supports the ejection target; an ejection head that ejects liquid to the ejection target from a nozzle; a carriage that reciprocates the ejection head in a main scanning direction at a predetermined height relative to the platen; and the platen Maintenance control means for recovering the ejection characteristics of the ejection head by ejecting liquid from the nozzle to a maintenance landing part provided in a maintenance area outside the ejection area where the ejection object is supported on the ejection head, and an ejection head for the platen A head position changing means for changing the height position of the jet head, and a position control means for controlling the height position of the jet head to be lower than the height position of the jet head during the jetting operation to the jetting object during the maintenance operation. A liquid ejecting apparatus comprising:   2. The liquid according to claim 1, wherein the position control means controls to lower a height position of the ejection head during the maintenance operation in correspondence with a height position of the ejection head during the ejection operation to the ejection target. Injection device.   3. The maintenance operation is performed at a predetermined time interval during an injection operation on an injection target, and the position control unit controls the height position of the injection head to be lowered every maintenance operation. The liquid ejecting apparatus described.   The maintenance landing portion is disposed at a position where the distance between the ejection head and the maintenance landing portion is the most suitable distance for maintenance in a state where the height position of the ejection head is set to the lowest position. The liquid ejecting apparatus according to any one of 1 to 3.   When performing the ejection operation on the ejection object in a state where the height position of the ejection head is set higher than the lowest position by the head position changing means, the position control means performs the height of the ejection head every time the maintenance operation is performed. The liquid ejecting apparatus according to claim 4, wherein the liquid ejecting apparatus is controlled to lower the position.   The maintenance landing portion is provided on the home position side of the carriage movement range, and the position control means controls to lower the height position of the ejection head every time a maintenance operation is performed on the maintenance landing portion on the home position side. Item 6. The liquid ejecting apparatus according to any one of Items 3 to 5.   6. The maintenance landing part is provided at both ends of a moving range of the carriage, and the position control means controls to lower the height position of the ejection head every time a maintenance operation is performed at both maintenance landing parts. The liquid ejecting apparatus according to any one of the above. A platen that supports the ejection target; an ejection head that ejects liquid to the ejection target from a nozzle; a carriage that reciprocates the ejection head in a main scanning direction at a predetermined height relative to the platen; and the platen Maintenance control means for recovering the ejection characteristics of the ejection head by ejecting liquid from the nozzle to a maintenance landing part provided in a maintenance area outside the ejection area where the ejection object is supported on the ejection head, and an ejection head for the platen A liquid ejecting apparatus maintenance method comprising: a head position changing means for changing a height position of the ejecting head, wherein the height of the ejecting head is higher than the height position of the ejecting head during the ejecting operation to the ejected object during the maintenance operation. A maintenance method for a liquid ejecting apparatus, wherein the position is controlled to be lowered.

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