JP2009023175A - Recording device and liquid jet device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a recorded image from degrading in quality due to an air flow created by a suction platen. <P>SOLUTION: The recording device includes the suction platen 250 by which recording paper 150 conveyed from a conveying suction 210 is sucked in a position opposite a recording head 232. The recording device also includes a control suction 258. If the recording paper 150 on the face where the suction platen 250 supports the recording paper 150 is present in the upstream position opposite the upstream nozzles of a plurality of nozzles 234 in the direction of paper feed and also in the downstream position opposite the downstream nozzles of the nozzles 234 in the direction of paper feed, the control section 258 causes the suction platen 250 to suck the recording paper 150, thereby positioning the recording paper 150 relative to the recording head 232. If the recording paper 150 is not present in the upstream position or downstream position either, the control section 258 limits the suction of the recording paper 150 by the suction platen 250 and causes the suction platen 250 to come into contact with the recording paper 150, thereby positioning the recording paper 150. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a recording apparatus and a liquid ejecting apparatus. More specifically, the present invention relates to a recording apparatus and a liquid ejecting apparatus that include a platen that is positioned by sucking a recording medium.

  There is an ink jet recording apparatus in which a liquid such as ink is ejected from a recording head provided with fine nozzles to adhere to a recording medium. This type of apparatus includes a recording head that reciprocates in a predetermined main scanning direction, and a conveyance unit that moves a recording medium in a conveyance direction that intersects the main scanning direction. By combining main scanning and conveyance, An image is formed by adhering liquid to an arbitrary area on the recording medium.

  In the ink jet recording apparatus as described above, the reciprocating range in the main scanning direction is determined by the specifications of the apparatus, and there are some that can record a large image such as a poster having a main scanning width exceeding 1 m. On the other hand, the length of the recording medium is not limited in the transport direction. Therefore, there is a recording apparatus that loads a roll on which a long recording medium is wound to form a long image on a banner, a hanging curtain, or the like.

  On the other hand, in an ink jet recording apparatus, a platen gap that is a distance between a nozzle and a recording medium strongly affects the quality of a recorded image. Accordingly, a platen for positioning the recording medium by supporting the recording medium from the back surface at a position facing the recording head is provided in the ink jet recording apparatus.

  The flatness of the recording medium also changes the platen gap. Therefore, in a recording apparatus that uses roll paper as a recording medium, there are cases in which winding wrinkles may remain on the recording medium drawn from the roll, and as measures against the high bending rigidity of the recording medium itself, etc. In some cases, a suction platen is provided. Many suction platens have a plurality of suction holes communicating with the surface thereof, and suck the recording medium by making the suction holes communicate with some decompression source.

  Patent Document 1 below describes a plotter including a platen that sucks a worksheet as a recording medium with a suction fan. In this plotter, the number of rotations of the suction fan changes according to the width of the worksheet, and the worksheet is reliably sucked.

  Patent Document 2 below describes a paper guide mechanism including a highly airtight fan box that houses a fan, and a guide plate that has air intake holes arranged on one surface of the fan box. With such a structure, the drawing medium can be efficiently adsorbed using a small capacity fan.

  Furthermore, Patent Document 3 below describes a platen including a suction fan that can select an operation according to the physical properties of the drawing medium. Thereby, it can convey, without roughening surface properties, such as a back print film.

  Furthermore, Patent Document 4 below describes forming a recess on the surface of a platen having a suction fan. Thereby, wrinkles of the recording material are less likely to occur.

As described above, in the recording apparatus provided with the suction platen, the recording medium is reliably positioned and an appropriate platen gap is maintained. Even when a curl or the like is attached, the recording medium becomes flat on the suction platen, and a uniform platen gap is maintained. Therefore, the high recording quality of the ink jet recording apparatus can be effectively utilized.
Japanese Patent Laid-Open No. 06-015902 JP 2001-089979 A JP 2002-127515 A JP 2006-231705 A

  In an ink jet recording apparatus, ink ejected from a recording head flies between the recording head and a recording medium due to inertia of kinetic energy given when ejected. On the other hand, in a period in which the front end side of the recording medium starts to approach the suction platen in the transport direction and a period in which the rear end side of the recording medium comes out of the suction platen in the transport direction, a part of the suction holes of the suction platen The recording head is exposed to the recording medium without being blocked by the recording medium.

  If the suction platen performs a suction operation in this state, the flying ink may be sucked into the suction holes. The ink whose orbit has been changed due to the suction is attached to a region different from the originally intended region on the surface of the recording medium. For this reason, in a recording apparatus having a suction platen, the quality of the recorded image may deteriorate at the upper and lower ends of the recording medium.

  Therefore, with the aim of solving the above problems, as a first embodiment of the present invention, there is provided a feeding unit that feeds a recording medium in the feeding direction, and a plurality of nozzles arranged along the feeding direction. And a recording head that ejects ink from a plurality of nozzles toward the recording medium fed to the feeding unit, and a negative pressure is formed on the surface, and the recording head is fed from the feeding unit at a position facing the recording head. A suction platen for sucking the recording medium, and a surface on which the suction platen supports the recording medium, an upstream position facing an upstream nozzle located upstream in the feeding direction among the plurality of nozzles, and a plurality of When the recording medium exists in both of the nozzles in the downstream position facing the downstream nozzle located downstream in the feeding direction, the recording medium is sucked by the suction platen to suck the recording medium. Recording medium For positioning the recording medium relative to the recording head by restricting the suction by the suction platen and supporting the suction platen when the recording medium does not exist at either the upstream position or the downstream position. And a recording device. As a result, when a part of the suction hole of the suction platen is exposed to the recording head, the suction by the suction platen is restricted, and the trajectory of the ink ejected from the recording head and flying is generated by the suction. Is prevented from changing. Therefore, a high-quality image can be formed even at the end in the transport direction of the recording medium.

  Furthermore, the recording apparatus may further include a detection unit that individually detects the presence of the recording medium at each of the upstream position and the downstream position. As a result, the operation of the suction platen can be reliably and accurately controlled based on the actually measured position of the recording medium conveyed onto the suction platen.

  Furthermore, the recording apparatus includes a detection unit that detects the presence of the recording medium. The detection unit feeds the recording medium after the feeding unit starts feeding the recording medium. The presence of the recording medium at the upstream position and the downstream position may be detected based on the amount sent. Thereby, the position of the recording medium on the surface of the suction platen can be accurately grasped without using an additional device such as a sensor for detecting the position of the recording medium. Therefore, it is possible to reliably control whether or not suction by the suction platen is possible.

  Further, as a second embodiment of the present invention, the apparatus includes a feeding unit that feeds the ejection target medium in the feeding direction, and a plurality of nozzles arranged along the feeding direction, and is fed to the feeding unit. A liquid ejecting head that ejects liquid from a plurality of nozzles toward the ejected medium, and a negative pressure is formed on the surface, and the ejected medium sent from the feeding unit is sucked at a position facing the liquid ejecting head. In the surface where the suction part and the suction part support the ejection target medium, the upstream position facing the upstream nozzle located upstream in the feeding direction among the plurality of nozzles and the feeding direction among the plurality of nozzles When the ejected medium is present in both downstream positions facing the downstream nozzle located on the downstream side, the ejected medium is sucked by the suction unit to position the ejected medium with respect to the liquid ejecting head, Upstream position and A liquid ejecting unit that includes a control unit that positions the ejected medium with respect to the liquid ejecting head by restricting the suction by the suction unit when the ejected medium is not present at any of the flow side positions and supporting the sucked unit An apparatus is provided. Thereby, the above-described effect can be enjoyed also in the liquid ejecting apparatus.

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. Further, a sub-combination of these feature groups can be an invention.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 is a perspective view showing an appearance of an ink jet recording apparatus 100 according to one embodiment. The ink jet recording apparatus 100 can perform recording on large sheets such as JIS standard A0 size and JIS standard B0 size, and roll paper having the same paper width as the single sheet.

  As shown in the figure, the ink jet recording apparatus 100 includes a casing 110 including an upper casing 112 and a lower casing 114 that are stacked on each other, and a small casing 116 that is suspended below the lower casing 114. Furthermore, it has the leg part 120 which supports the housing | casing 110 from the downward direction. Thereby, a space for discharging the recording paper 150 can be formed below the housing 110.

  The upper housing 112 accommodates a recording head 232 and the like which will be described later. On the other hand, the lower housing 114 accommodates a suction platen 250, which will be described later. Further, the small casing 116 accommodates the waste liquid absorber 260. The waste liquid absorber 260 accumulates ink that has not been adhered to the recording paper 150 while being discharged from the recording head 232.

  The upper casing 112 is provided with an operation panel 130 that is used when the ink jet recording apparatus 100 is operated in a stand-alone manner. The operation panel 130 may be provided with a display panel, a lamp, and the like that indicate the operation state of the ink jet recording apparatus 100. On the other hand, the lower housing 114 is provided with a cartridge holder 140 into which an ink cartridge 240 containing ink to be supplied to the recording head 232 is loaded.

  In the ink jet recording apparatus 100 as described above, the recording sheet 150 on which an image is recorded is sent forward from between the upper casing 112 and the lower casing 114. The fed recording sheet 150 hangs downward due to its own weight. Therefore, a guide surface 252 that smoothly guides the recording paper 150 is formed at the front end of the suction platen 250 that can be seen in the gap between the upper housing 112 and the lower housing 114.

  FIG. 2 is a perspective view showing the ink jet recording apparatus 100 as seen from the back. As shown in the figure, on the rear surface of the ink jet recording apparatus 100, a spindle 160 that is horizontally stretched and a roll 152 that is horizontally supported by being inserted through the spindle 160 are disposed at the rear of the lower housing 114. Installed. The recording paper 150 shown in FIG. 1 is drawn from the roll 152, passed through the inside of the housing 110, and drawn to the front.

  FIG. 3 is a perspective view showing the internal mechanism 200 of the ink jet recording apparatus 100. The internal mechanism 200 appears when the casing 110 is removed from the ink jet recording apparatus 100.

  As shown in the figure, a guide rail 220 that extends in the horizontal direction and a carriage 230 that reciprocates horizontally along the guide rail 220 are disposed inside the upper housing 112. As will be described later, a recording head 232 that ejects ink is mounted on the carriage 230. Further, below the guide rail 220, a transport unit 210 that moves the recording paper 150 from the rear to the front is disposed.

  On the other hand, a suction platen 250 having a horizontal surface is disposed below the guide rail 220 inside the lower housing 114. The lower housing 114 also houses the ink cartridge 240. Furthermore, the waste liquid absorber 260 accommodated in the small casing 116 is exposed to the right side of the leg portion 120 in the drawing.

  FIG. 4 is an enlarged perspective view of a part of the internal mechanism 200 shown in FIG. As shown in the figure, a conveyance unit 210 including a conveyance driving roller 212 and a conveyance driven roller 214 is formed behind the suction platen 250.

  The transport driving roller 212 is rotationally driven by a transport motor (not shown). On the other hand, the transport driven roller 214 is urged downward through the roller holder 216 and is rotated in contact with the transport drive roller 212.

  When the recording paper 150 is sandwiched between the transport driving roller 212 and the transport driven roller 214 as described above, the recording paper 150 is pressed against the transport driving roller 212 by the transport driven roller 214 and sucked according to the rotation of the transport driving roller 212. It is sent out to the upper surface of the platen 250.

  FIG. 5 is a plan view schematically showing a state where the transport path 300 as described above is looked down from above. As shown in the figure, the recording paper 150 drawn from the roll 152 loaded behind the ink jet recording apparatus 100 is transported in the transport direction M by the transport unit 210 and sent onto the front suction platen 250. .

  The suction platen 250 has a number of suction holes 259 on its surface. As will be described later, since the suction hole 259 forms a negative pressure on the surface of the suction platen 250, the recording paper 150 is attracted to the suction platen 250. As a result, even when curl or the like is generated on the recording paper 150, the recording paper 150 is flattened by being attracted to the surface of the suction platen 250. Therefore, the interval with respect to the recording head 232 is accurately maintained, and the quality of the recorded image is also kept high.

  In this state, the carriage 230 reciprocates on the suction platen 250 along the guide rail 220. Therefore, by combining the driving of the conveyance of the recording paper 150 and the reciprocating movement of the recording head 232, ink can be ejected and adhered to an arbitrary area of the recording paper 150.

  The recording head 232 mounted on the carriage 230 has a large number of nozzles 234. As a result, a large number of pixels can be formed by one pass of the carriage 230, so that the recording speed can be improved.

  In addition to the recording head 232, sensors 236 and 238 for detecting whether or not the recording paper 150 exists below are mounted on the carriage 230. The sensors 236 and 238 are arranged in the conveyance direction M of the recording paper 150, and the operation thereof will be described later.

  FIG. 6 is a cross-sectional view schematically showing the structure and function of the suction platen 250. As shown in the figure, the suction platen 250 has a number of suction holes 259 on its upper surface. The lower ends of the suction holes 259 communicate with the decompression chambers 253 formed inside the suction platen main body 251, respectively.

  The decompression chamber 253 is coupled to the suction fan 254 via the duct 255. The suction fan 254 is coupled to the power supply 256 via the switch 257 and stops or operates by opening and closing the switch 257. Therefore, a suction force can be generated in the suction platen 250 by the electrical control via the switch 257, and it can be stopped.

  The switch 257 is controlled to be opened and closed by the control unit 258. The control unit 258 opens and closes the switch 257 based on inputs from the sensors 236 and 238 mounted on the carriage 230 together with the recording head 232.

  Here, one of the sensors 236 is the recording paper on the surface of the suction platen 250 at the position of the nozzle 234 located on the most upstream side in the conveyance direction M of the recording paper 150 among the many nozzles 234 formed in the recording head 232. Whether or not 150 exists is detected and notified to the control unit 258. On the other hand, the other sensor 238 is the position of the nozzle 234 located on the most downstream side with respect to the conveyance direction M of the recording paper 150 among the many nozzles 234 formed in the recording head 232, and the recording paper 150 on the surface of the suction platen 250. Is detected and notified to the control unit 258.

  The control unit 258 notified of the presence or absence of the recording paper 150 from the sensors 236 and 238 controls the opening and closing of the switch 257 as will be described later with reference to FIGS. The sensors 236 and 238 as described above can be formed by an optical sensor that detects a change in reflectance on the surface of the suction platen 250, for example.

  FIG. 7 is a cross-sectional view schematically showing the state of the suction platen 250 at the beginning of the recording operation on the recording paper 150. In the state shown in this figure, the leading edge of the recording paper 150 sent out in the transport direction M from the transport unit 210 has advanced to the middle of the suction platen 250.

  At this time, of the sensors 236 and 238 mounted on the carriage 230, the upstream sensor 236 in the transport direction M detects the presence of the recording paper 150. However, the downstream sensor 238 where the leading edge of the recording paper 150 has not reached does not detect the presence of the recording paper.

  In the state as described above, the control unit 258 keeps the switch 257 open and does not operate the suction fan 254, so that suction force is not generated in the suction platen 250. However, as shown in the figure, the conveyance unit 210 is disposed so that the conveyance driven roller 214 is displaced downstream with respect to the vertical line passing through the central axis of the conveyance driving roller 212, so that the recording paper 150 is directed slightly downward. Send out while energizing. Accordingly, the leading edge of the recording paper 150 advances along the upper surface of the suction platen 250 due to the elasticity or rigidity of the recording paper 150 itself. Thereby, on the suction platen 250, the platen gap which is the distance between the recording head 232 and the recording paper 150 is accurately maintained.

  Further, since the suction fan 254 is not activated, the airflow sucked into the suction hole 259 is not generated. Therefore, the ink droplets ejected from the recording head 232 near the front end of the recording paper 150 are not guided by the air current and do not change the landing position. Thereby, while maintaining an accurate platen gap, ink droplets can be ejected with proper activation, so that the quality of the recorded image is maintained high.

  FIG. 8 is a cross-sectional view schematically showing the state of the suction platen 250 in the next stage. In the state shown in this figure, the leading edge of the recording paper 150 sent out in the transport direction M from the transport unit 210 has advanced to the vicinity of the end of the suction platen 250.

  At this time, the sensors 236 and 238 mounted on the carriage 230 both detect the presence of the recording paper 150. Therefore, the control unit 258 closes the switch 257 and operates the suction fan 254. As a result, the suction platen 250 exerts a suction force to suck the recording paper 150.

  Therefore, even when curl or the like occurs in the recording paper 150, the upper surface of the suction platen 250 becomes flat, and an appropriate platen gap is maintained. In the above state, since the recording paper 150 exists below the recording head 232, the airflow flowing into the suction hole 259 does not disturb the trajectory of the ink droplets ejected from the recording head 232.

  In the above embodiment, the suction fan 254 is operated or stopped for the purpose of simplifying the description. However, the suction platen 250 may be used as long as it does not disturb the trajectory of the ink droplets ejected from the recording head 232. Can be working. Therefore, when either of the sensors 236 and 238 does not detect the recording sheet 150, the rotation speed of the suction fan 254 can be reduced. As a result, the suction fan 254 can continue to maintain a weak suction force, and the activation time when the recording paper 150 is sucked again can be shortened.

  Further, in the above embodiment, the sensors 236 and 238 are disposed immediately above the nozzle 234. However, in the ink jet recording apparatus 100, the conveyance amount of the recording paper 150 by the conveyance unit 210 is precisely controlled. Therefore, once the control unit 258 detects, for example, the leading end position of the conveyed recording paper 150, the control unit 258 can know the leading end position of the recording paper 150 from the transport amount by the transport unit 210 thereafter. Accordingly, the number and arrangement of the sensors 236 and 238 to be mounted can be selected in a wide range.

  FIG. 9 is a perspective view showing an appearance of an ink jet recording apparatus 400 according to another embodiment. As shown in the drawing, an ink jet recording apparatus 400 includes a recording unit casing 414, a rear casing 412 protruding rearward thereof, and a paper cartridge 416 mounted on the recording unit casing 414 from the entire surface. 410.

  The rear casing 412 can be loaded with roll paper (not shown). The roll paper drawn from the loaded roll paper passes through the inside of the recording unit housing 414 and is discharged to a discharge tray 470 formed on the upper surface of the paper cartridge 416. The ink jet recording apparatus 400 can also record an image on a single sheet of recording paper 154 loaded in the paper cartridge 416. Also in this case, the recording sheet 154 on which the image is recorded is folded back in the recording unit housing 414 and discharged to the discharge tray 470.

  FIG. 10 is a perspective view showing the internal mechanism 500 of the ink jet recording apparatus 400. As shown in the figure, inside the recording unit casing 414, a conveying unit 510, a suction platen 550, and a discharge driven roller 574 that are parallel to each other are sequentially arranged. The suction platen 550 disposed in front of the transport unit 510 has a horizontal surface having a number of suction holes 559.

  The conveyance unit 510 includes a conveyance driving roller 512 and a conveyance driven roller 514, as in the case of the ink jet recording apparatus 100. The transport driving roller 512 is rotationally driven by a transport motor (not shown). On the other hand, the transport driven roller 514 is urged downward through a roller holder 516 that rolls about the shaft 517, and is rotated in contact with the transport drive roller 512. Therefore, when the recording paper 150 is sandwiched between the transport driving roller 512 and the transport driven roller 514, the recording paper 150 is pressed against the transport driving roller 512 by the transport driven roller 514, and the suction platen 550 is rotated according to the rotation of the transport driving roller 512. It is sent out to the top surface.

  Further, the ink jet recording apparatus 400 includes a discharge driven roller 574. The reason is that, when an image is recorded on a single sheet of recording paper 154, if the trailing edge of the recording paper 154 passes through the transport unit 510, it cannot be transported further. However, since the discharge driven roller 574 contacts the recording sheet 154 having the recorded image, a gear-shaped or spur-shaped roller is used for the purpose of reducing the contact area.

  FIG. 11 is a diagram showing a conveyance path 600 of the recording paper 154 in the ink jet recording apparatus 400, and shows a state where the conveyance path 600 is looked down from above. In addition, a roll 552 inserted through a spindle 560 is loaded behind the ink jet recording apparatus 400. In this embodiment, a conveyance path 600 for a single sheet of recording paper 154 fed from the paper cartridge 416 is shown. .

  As shown in the figure, the conveyance path 600 is formed around the suction platen 550. Above the suction platen 550, a guide rail 520 extending in the longitudinal direction and a carriage 530 that reciprocates along the guide rail 520 are disposed. As will be described later, a recording head 532 that ejects ink is mounted on the carriage 530.

  On the other hand, the suction platen 550 has a number of suction holes 559 on its surface. As will be described later, since the suction hole 559 forms a negative pressure on the surface of the suction platen 550, the recording paper 154 is adsorbed by the suction platen 550. Thereby, even when the recording paper 154 is curled or the like, it becomes flat by being adsorbed on the surface of the suction platen 550. Therefore, the interval with respect to the recording head 532 is accurately maintained, and the quality of the recorded image is also kept high. The structure of the suction platen 550 itself is substantially the same as the suction platen 250 shown in FIG.

  In this state, the carriage 530 reciprocates on the suction platen 550 along the guide rail 520. Accordingly, by combining the driving of the conveyance of the recording paper 154 and the reciprocating movement of the recording head 532, ink can be ejected and adhered to an arbitrary region of the recording paper 154.

  Note that the recording head 532 mounted on the carriage 530 has a large number of nozzles 534. Thereby, a large number of pixels can be formed by one pass of the carriage 530, and the recording speed can be improved.

  In addition to the recording head 532, sensors 536 and 538 for detecting whether or not the recording paper 154 exists below are mounted on the carriage 530. The sensors 536 and 538 are arranged in the conveyance direction M of the recording paper 150, and the operation thereof will be described later.

  FIG. 12 is a cross-sectional view schematically showing a state in which a recording operation on the recording paper 154 is being performed on the suction platen 550. In the state shown in this figure, the leading end of the recording paper 154 sent upstream in the transport direction M by the transport unit 210 reaches the discharge driven roller 574.

  Although hidden in FIGS. 10 and 11, a discharge driving roller 572 that is rotationally driven is provided below the discharge driven roller 574. Thereby, the recording paper 154 can be carried out to the outside on the discharge side alone.

  In the state shown in FIG. 12, the sensors 236 and 238 mounted on the carriage 230 both detect that the recording paper 154 exists immediately below. In this case, the control unit 258 keeps the switch 257 closed and keeps the suction fan 254 operating. As a result, the suction platen 250 exerts a suction force to suck the recording paper 150.

  Accordingly, the recording paper 154 having curl and the like is also flattened on the suction platen 250, and an appropriate platen gap is maintained. Further, since the recording paper 150 exists below the recording head 232, the airflow flowing into the suction hole 259 does not disturb the trajectory of the ink droplets ejected from the recording head 232.

  FIG. 13 shows a state in which the rear end of the recording paper 154 has passed over the conveyance unit 510 and has reached the top of the suction platen 550. As shown in the figure, the rear end of the recording paper 154 is located below the recording head 532. In this case, the recording paper 154 does not exist below the upstream carriage sensor 536 in the transport direction M among the sensors 536 and 538. For this reason, the control unit 258 opens the switch 257 to stop the suction fan 254.

  Thereby, the trajectory of the ink droplets ejected from the recording head 532 is not disturbed. Further, since the length of the recording paper 154 extending behind the discharge driven roller 574 is short, the recording paper 154 is supported in contact with the surface of the suction platen 550 by its own rigidity. Therefore, the platen gap does not change due to the suction of the suction platen 550 being stopped.

  For the purpose of simplifying the description, the sensors 536 and 538 are arranged directly above the nozzle 534 in the above embodiment. However, in the ink jet recording apparatus 400, the conveyance amount is precisely controlled by the conveyance unit 510 of the recording paper 154. The dimensions of the recording paper 154 in the transport direction are known in advance. Therefore, once the control unit 258 detects, for example, the leading end position of the transported recording paper 154, the control unit 258 can know the leading end position of the recording paper 154 from the transport amount by the transport unit 510 thereafter.

  Further, the rear end position of the recording paper 154 can be known from the discharge amount by the discharge driving roller 572 and the discharge driven roller 574. Therefore, the number and arrangement of the sensors 536 and 538 to be mounted can be selected in a wide range.

  FIG. 14 is a cross-sectional view schematically showing the structure and function of another suction platen 350 that can be used in place of the suction platen 250 shown in FIG. As shown in the figure, the suction platen 350 has a number of suction holes 259 on its upper surface. The lower ends of the suction holes 259 communicate with the decompression chambers 353 formed inside the suction platen main body 351, respectively.

  The decompression chamber 353 is coupled to the suction fan 254 via the duct 355. Further, the suction fan 254 communicates with the outside of the platen main body 351 through ducts 357 and 359. However, a flap 352 that is opened and closed by an actuator 354 is provided between the ducts 357 and 359. The suction fan 254 is connected to the power source 256 and continuously operated.

  The suction platen having the above structure can generate or stop the suction force by opening and closing the flap 352. That is, when the flap 352 closes between the duct 357 and the duct 359 as shown in the figure, the suction force generated by the suction fan 254 is reflected in the suction hole 259 via the decompression chamber 353. On the other hand, when the flap 352 communicates between the duct 357 and the duct 359, the suction force generated by the suction fan 254 is offset by the air flowing in from the duct 357 and the duct 359. Can not do it. Accordingly, no negative pressure is generated in the suction hole 259.

  The structures of the sensors 236 and 238 mounted on the carriage 230 together with the recording head 232 and the control unit 258 notified of the presence or absence of the recording paper 150 from the sensors 236 and 238 are the same as those of the suction platen 250. However, the control unit 258 controls the operation of the actuator 354 instead of the switch 257.

  By adopting such a structure, the start and stop of suction in the suction platen 350 can be speeded up. Therefore, suction can be started or stopped immediately in response to the arrival or withdrawal of the recording paper 150, 154. In addition, the suction fan 254 can continue to operate in a steady state, and wear and tear are reduced because it is avoided to repeatedly start and stop exhausted. Furthermore, since the suction fan 254 is operated steadily, the noise generated by the suction fan 254 is also reduced psychologically.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. Furthermore, it is apparent from the description of the scope of claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

1 is a perspective view illustrating an appearance of an ink jet recording apparatus 100 as viewed from the front. 1 is a perspective view illustrating an appearance of an inkjet recording apparatus 100 as viewed from the back. 2 is a perspective view showing an internal mechanism 200 of the ink jet recording apparatus 100. FIG. FIG. 4 is an enlarged view showing a part of a conveyance path 300 formed in an internal mechanism 200. 3 is a diagram illustrating a planar layout of a conveyance path 300 for a recording sheet 150. FIG. It is a figure which shows typically the structure and function of the suction platen 250. It is a figure which shows typically the state of the suction platen 250 in one operation | movement stage. It is a figure which shows typically the state of the suction platen 250 in another operation | movement stage. It is a perspective view which shows the external appearance of the inkjet recording device 400 which concerns on other embodiment. 2 is a perspective view showing an internal mechanism 500 of the ink jet recording apparatus 400. FIG. 6 is a diagram illustrating a conveyance path 600 of a recording sheet 154 in the internal mechanism 500. FIG. It is a figure which shows typically the state of the suction platen 250 in one operation | movement stage. It is a figure which shows typically the state of the suction platen 250 in another operation | movement stage. It is a figure which shows typically the structure and function of the suction platen 350 which concern on another form.

Explanation of symbols

100, 400 Inkjet recording device, 110, 410 housing, 112 upper housing, 114 lower housing, 116 small housing, 120 legs, 130, 430 operation panel, 140 cartridge holder, 150, 154 recording paper, 152 , 552 roll, 160, 560 spindle, 200, 500 internal mechanism, 210, 510 transport unit, 212, 512 transport drive roller, 214, 514 transport driven roller, 216, 516 roller holder, 517 shaft, 220, 520 guide rail, 230, 530 Carriage, 232, 532 Recording head, 234, 534 Nozzle, 236, 238, 536, 538 Sensor, 240 Ink cartridge, 250, 350, 550 Suction platen, 251, 351, 551 Platen body, 252 Guide surface, 253, 353, 553 Pressure reducing chamber, 254 Suction fan, 255, 355, 357, 359, 555 Duct, 256 Power supply, 257 Switch, 258 Control unit, 259, 559 Suction hole, 300, 600 Conveyance path, 352 Flap 354 Actuator, 412 Rear housing, 414 Recording unit housing, 416 Paper cartridge, 470 Ejection tray, 572 Ejection drive roller, 574 Ejection driven roller

Claims (4)

A feeding unit that feeds the recording medium in the feeding direction;
A plurality of nozzles arranged along the feeding direction, and a recording head that ejects ink from the plurality of nozzles toward the recording medium fed to the feeding unit;
A suction platen that forms a negative pressure on the surface and sucks the recording medium fed from the feeding unit at a position facing the recording head, and a surface on which the suction platen supports the recording medium, Among the plurality of nozzles, an upstream position facing an upstream nozzle located upstream in the feeding direction, and a downstream facing a downstream nozzle located downstream in the feeding direction among the plurality of nozzles When the recording medium exists at both of the side positions, the recording medium is positioned with respect to the recording head by causing the suction platen to suck the recording medium, and the upstream position and the downstream side When the recording medium is not present at any of the positions, the suction platen restricts the suction by the suction platen and supports it by the front. And a controller that positions the recording medium with respect to the recording head.   The recording apparatus according to claim 1, further comprising a detection unit that individually detects the presence of the recording medium at each of the upstream position and the downstream position.   A detection unit configured to detect the presence of the recording medium, the detection unit feeding the recording medium after the feeding unit started feeding the recording medium; The recording apparatus according to claim 1, wherein presence of the recording medium at the upstream position and the downstream position is detected based on a quantity. A feeding unit that feeds the ejected medium in the feeding direction;
A liquid ejecting head having a plurality of nozzles arranged along the feeding direction, and ejecting liquid from the plurality of nozzles toward the ejected medium fed to the feeding unit;
On the surface that forms a negative pressure on the surface and sucks the ejected medium sent from the feeding unit at a position facing the liquid ejecting head, and the surface on which the sucking unit supports the ejected medium, Among the plurality of nozzles, an upstream position facing an upstream nozzle located upstream in the feeding direction, and a downstream nozzle located downstream in the feeding direction among the plurality of nozzles. When the medium to be ejected exists at both downstream positions, the medium to be ejected is positioned with respect to the liquid ejecting head by causing the suction unit to suck the medium to be ejected, and the upstream position and the When the ejected medium is not present at any of the downstream positions, the suction by the suction unit is limited and supported by the suction unit, so that the liquid jet head is not supported. And a control unit that positions the medium to be ejected.

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