JP2016221942A - Printer and platen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer capable of reliably performing a margin-less print while suppressing flotation, deflection or the like of a sheet, and realizing both reliable waste ink recovery and sheet suction without enlarging the printer.SOLUTION: The printer includes a suction part for applying a negative pressure to a sheet to bring the sheet into contact with a support part 14 by suction, and ink receiving parts 31A and 31B for receiving ink discharged in the outside of the sheet. The waste ink discharged to the ink receiving parts is introduced to a waste ink discharge port 30 formed in an outer peripheral wall 20 of a platen via waste ink channels 31f1, 31f2 and 31f3. In the suction part, a sheet suction mechanism for applying the negative pressure is adjacently arranged, and a discharge mechanism for forcibly discharging the waste ink in the outside of the platen is connected to the waste ink discharge port.SELECTED DRAWING: Figure 8

Description

  The present invention relates to an inkjet printing apparatus including a platen that supports a sheet.

  The ink jet printing apparatus disclosed in Patent Document 1 uses a suction platen that adsorbs a sheet with a negative pressure. Further, a duct and a waste ink tank are disposed under the platen in order to collect ink (waste ink) that has been discarded by the borderless printing.

JP 2006-187903 A

  In Patent Document 1, the guide channel from the platen to the waste ink tank is arranged on the side of the duct, that is, on the same plane as the duct. For this reason, the volume of the duct must be reduced, and the negative pressure control by the negative pressure generating fan tends to become unstable. Further, the arrangement of the waste ink tank is also limited. Therefore, in order to achieve both the waste ink collection and the sheet suction, it is inevitable that the entire apparatus is enlarged.

  The present invention can surely perform borderless printing while suppressing sheet floating and bending by suction of the sheet, and realizes both reliable waste ink recovery and sheet suction without increasing the size of the apparatus. It is an object of the present invention to provide a printing apparatus and a platen that can be used.

  An embodiment of the present invention that solves the above-described problem is a printing apparatus that includes a print head that ejects ink and a platen that supports the sheet so as to face the print head, and the platen supports the sheet. A support portion, an ink receiving portion for receiving ink discharged by the print head on the outside of the sheet supported by the support portion, and waste ink discharged to the ink receiving portion are formed on the outer peripheral wall of the platen. A waste ink flow path leading to the discharge port, and a discharge mechanism for discharging the waste ink is connected to the discharge port.

  According to the present invention, it is possible to reliably perform borderless printing while suppressing sheet floating and bending by suction of the sheet, and to achieve both reliable waste ink recovery and sheet suction without increasing the size of the apparatus. Realize.

1 is a perspective view illustrating an overall configuration of a printing apparatus main body. It is a vertical side view of a printing apparatus. It is a perspective view which shows a platen and its peripheral structure. It is a perspective view showing the whole platen composition. It is an enlarged view which shows a part of platen. It is a vertical side view which shows a part of platen. It is a perspective view which shows the state which has arrange | positioned the ink absorber to the ink discard groove | channel. It is a vertical side view of a platen. It is a vertical front view of a platen. It is a vertical side view which shows a sheet | seat adsorption | suction mechanism. It is a perspective view which shows the suction pump of a waste ink discharge mechanism. It is a top view which shows the waste ink collection | recovery path | route of a waste ink discharge mechanism. FIG. 2 is a block diagram illustrating a control system configuration of a printing apparatus. It is a vertical side view which shows printing operation. It is a vertical side view which shows printing operation. It is an enlarged view which shows a part of platen. It is a vertical side view which shows a part of platen. It is an enlarged view which shows a part of platen. It is a vertical side view which shows a part of platen. It is a flowchart which shows a tube pump drive sequence.

  An embodiment of a printing apparatus according to the present invention will be described. Hereinafter, an example of a serial type inkjet printing apparatus that performs printing by reciprocating a print head capable of ejecting ink in a direction intersecting the sheet conveyance direction with respect to a sheet intermittently conveyed in a certain direction will be described. To do. The present invention is not limited to a serial type printing apparatus, but can be applied to a line printing apparatus that performs continuous printing using a long print head. The printing apparatus is not limited to a single-function printing apparatus, but can be applied to a multifunction printer having both a copy function and a facsimile function.

1. Outline of Apparatus The configuration of the printing apparatus 1 in the present embodiment will be described. FIG. 1 is a perspective view showing an overall configuration of a printing apparatus 1 in which an exterior portion is removed from the printing apparatus 1, and FIG. 2 is a longitudinal side view of the printing apparatus 1 shown in FIG.

  1 and 2, a feeding device 40 is provided on the back side of the printing apparatus 1. The feeding device 40 separates the sheets one by one from the bundle of cut sheets (hereinafter simply referred to as “sheets”) stacked on the feeding tray 40 a by the rotation of the feeding roller 6, and transport means such as the transport roller 7. To feed. The printing apparatus 1 is provided with a carriage 4 on which a print head 3 that can eject ink is mounted. The carriage 4 is supported so as to be capable of reciprocating along a carriage guide shaft 41 and a carriage rail 42 provided along a direction (X direction) intersecting (orthogonal in the embodiment) with respect to the sheet conveyance direction (Y direction). Has been. The movement of the carriage 4 and the print head 3 along the X direction is also referred to as scanning in the following description. The X direction is the carriage movement direction and also the sheet width direction of the conveyed sheet. The Y direction is the sheet conveying direction.

  One sheet separated and fed by the feeding device 40 from a bundle of sheets stacked on the feeding tray 40a is printed by a first conveying roller pair (conveying means) composed of a conveying roller 7 and a pinch roller 8 by a print head. 3 is conveyed onto a platen 9 that supports a sheet at a position opposite to the platen 9. Here, the carriage 4 on which the print head 3 is mounted moves in the X direction, and ink is ejected from the print head 3 toward the sheet. A sheet detection sensor for detecting the end of the sheet is provided on one side surface of the carriage 4. Based on the detection output from the sheet detection sensor, the relative position between the sheet and the print head and the start of printing on the sheet are provided. Timing is determined.

  When printing for one scanning is performed on the sheet, the sheet is conveyed by a predetermined amount in the Y direction by the first conveying roller pair. By repeating the scanning of the print head 3 and the conveyance of the sheet as described above, printing on the sheet is performed in a serial manner.

  The printed sheet 2 is discharged onto the discharge tray 12 by a second conveyance roller pair (conveying means) including a discharge roller 10 and a spur 11 disposed downstream of the platen 9 in the sheet conveyance direction (Y direction). Is done. The feeding device 40, the carriage guide shaft 41, the carriage rail 42, and the platen 9 are fixedly supported by the chassis 28 that forms the skeleton of the printing apparatus 1.

2. Next, the structure of the platen 9 used in the printing apparatus will be described. FIG. 3 is a perspective view showing the platen 9 and its peripheral structure. As shown in FIG. 3, the platen 9 is disposed between a first transport roller pair including a transport roller 7 and a pinch roller, and a second transport roller pair including a discharge roller 10 and a spur 11. The platen 9 supports a sheet conveyed by the first and second conveying roller pairs on a surface (back surface) opposite to the print surface.

2.1 Sheet Support Section FIG. 4 is a perspective view showing the overall configuration of the platen 9. The platen 9 is formed with a sheet support portion (support portion) 14 capable of supporting the back surface of the sheet while suppressing the floating and bending of the sheet in order to keep an appropriate distance between the discharge port surface of the print head 3 and the sheet. Yes. A plurality of sheet support portions 14 are formed along the longitudinal direction (X direction) of the platen 9.

  FIG. 5 is an enlarged view showing a part of the platen 9 shown in FIG. The sheet support portion 14 is formed in a rectangular frame shape by a convex portion. The sheet support surface 13 of the support portion 14 has a width of about several millimeters. An adsorption recess 17 is formed on the upper portion of the sheet support portion 14 to form a recess that is one step lower than the sheet support surface 13. A suction hole (suction part) 18 penetrating the platen 9 is formed on the bottom surface of the suction recess 17. The suction hole 18 communicates with a negative pressure generating means 19 described later. The negative pressure generated by the negative pressure generating means 19 is applied to the suction recess 17 through the suction hole 18. The sheet passing through the sheet support surface 13 is sucked by the negative pressure applied to the suction recess 17 and is sucked by the sheet support surface 13. As a result, the sheet is conveyed while being kept in a flat state without being bent or floated, and the distance between the discharge port surface 3a of the print head 3 and the sheet 2 (the inter-sheet distance) is set to an appropriate preset distance. Kept.

  Further, in order to correspond to a plurality of types of sheets having different sheet widths (sheet sizes in the X direction), five types of sheet support portions 14 (first to sixth sheet support portions (14A to 14F) having different sizes are provided. (Refer to FIG. 4 and FIG. 7) Among them, the first sheet support portion 14A to the fifth sheet support portion 14E are formed with a suction recess 17 having a relatively large area. Is formed with a suction hole 18. However, since the smallest fifth sheet support portion 14F has a small area of the suction recess 17, the suction hole 18 is omitted. The sheet support portion 14F corresponds to the sheet and the half-cut width size sheet, and suction holes are omitted in the suction recesses 17 of the sheet support portions 14F.

  Further, the first, second, and third sheet support portions 14A, 14B, and 14C having a relatively large frame shape have the same height as the sheet support surface 13 in order to prevent the sheet from falling into the suction concave portion 17. The intermediate rib 14r having the shape is formed in a direction (Y direction) orthogonal to the X direction. Here, three intermediate ribs 14r are formed on the first sheet support portion 14A, and two 14r are formed on the second sheet support portion 14B and the third sheet support portion 14C, respectively. Is a support surface that is continuous with the sheet support surface 13 having a frame shape. However, the intermediate rib 14r is not formed on the fifth and sixth sheet support portions 14E and 14F. Note that the number of suction holes 18, the diameter of the suction holes, the number of intermediate ribs, and the like are preferably set as appropriate according to the size of the sheet support portion 14 and the suction recess portion determined by the corresponding sheet size and the like.

  An upstream side sheet support portion 32 that supports the sheet conveyed from the conveyance roller 7 from the back surface is formed further upstream than a later-described rear end ink discarding groove 31 </ b> B formed in the platen 9. Further, a downstream side sheet support portion 33 that supports the sheet conveyed by the discharge roller 10 from the back side is formed further downstream than a later-described leading edge ink discarding groove 31 </ b> A formed in the platen 9. Each of the upstream sheet support portion 32 and the downstream sheet support portion 33 is formed by a rib-like convex portion extending along the sheet conveying direction (Y direction), as shown in FIG. , A plurality of them are arranged in the X direction at regular intervals.

  Further, the upstream sheet support part 32 and the downstream sheet support part 33 are formed so that the positions of the tops thereof are the same height as the sheet support surface (contact part) 13 of the sheet support part 14 described above. The upstream sheet support portion 32 and the downstream sheet support portion 33 prevent the sheet 2 from dropping or getting caught when the leading end or the trailing end of the sheet 2 passes through the sheet supporting portion 14 or each roller. Fulfills the function.

2.2 Ink discarding section In order to reliably perform so-called borderless printing in which no margin is provided at the periphery of the sheet and recording is performed on the entire sheet, it is necessary to eject ink beyond the edge of the sheet. Necessary. In addition, in the ink jet printing apparatus, so-called preliminary ejection, in which ink is ejected to the outside of the sheet immediately before the printing operation, is performed to stabilize the ink ejection performance of the print head 3. The ink ejected to the outside of such a sheet is received by an ink receiving portion formed on the platen 9. In this example, as an ink receiving portion, a front end ink discarding groove (first ink receiving portion) 31A for receiving ink discharged outside the front end of the sheet, and a rear end for receiving ink discharged outside the rear end of the sheet And an ink discarding groove (second ink receiving portion) 31B. Furthermore, in this example, left and right end ink discarding grooves 34 (third ink receiving portions) that receive ink ejected outside the left and right ends (sheet side ends) of the sheet in the sheet width direction are provided as the ink receiving portions. It has been.

  FIG. 6 is a longitudinal side view showing a part of the platen 9, and shows a cross section of the leading-end ink discarding groove 31 </ b> A and the trailing-end ink discarding groove 31 </ b> B of the platen 9. As shown in FIG. 6, the front end ink discarding groove 31 </ b> A is elongated in the X direction adjacent to the downstream side of the sheet support portion 14, and the rear end ink discard groove 31 </ b> B is formed on the sheet support portion 14. It is elongated in the X direction adjacent to the upstream side. The leading-edge ink discarding groove 31 </ b> A is formed by a bottom surface 31 a lower than the sheet support surface 13, a downstream side wall surface 31 d of the sheet support portion 14, and a side wall surface 31 e of the downstream sheet support portion 33. The rear end ink discarding groove 31 </ b> B is formed by a bottom surface 31 a lower than the sheet support surface 13, an upstream side wall surface 31 c of the sheet support portion 14, and a side wall surface 31 b of the upstream side sheet support portion 32. The leading-end ink discarding groove 31A and the trailing-end ink discarding groove 31B are formed in such a volume that the ink does not overflow when the ink ejected from the print head 3 is received.

  On the other hand, in order to reliably perform borderless printing on the left and right edges (sheet side edges) of the sheet, when the print head 3 ejects ink while scanning in the X direction, the ink is extended to the outside of the left and right edges of the sheet. Need to be discharged. In addition, even when the sheet width of the sheet to be used is changed, the left and right edge ink strikes that match the width of each sheet are received on the platen so that the ink ejected outside the edge of the sheet can be received. A discard groove 34 is provided (see FIGS. 4 and 5).

  As the size of the sheet for borderless printing, a standard size sheet such as L size, 2L size, postcard, A4, letter, A3, legal, A2 is mainly used. Therefore, in accordance with these sheet sizes, a plurality of ink discard grooves 34 are arranged at the left and right sheet edge positions of each sheet. As described above, the front-side ink discarding groove 31A, the rear-end ink discarding groove 31B, and the right-and-left end ink-discarding grooves 34 are arranged on the surface side of the platen 9 in a lattice shape. Is formed.

  The arrangement of the sheet support portion 14 in the sheet width direction (X direction) is determined according to the reference of the print position. In the present embodiment, a so-called center reference sheet supply in which the reference of the print position is set at the center of the width of the print sheet is employed. With the center reference, the sheet is conveyed so that the center of the sheet width (print width) and the center of the platen 9 in the width direction coincide with each other in various sheet widths. Accordingly, the sheet supporting portions 14 are arranged symmetrically so that the left and right end ink discarding grooves 34 are formed at positions that are symmetric with respect to the center position of the width of the platen 9 in the X direction. When performing borderless printing, the ink discard groove 34 for the left and right edges is positioned on the inside by about 2 mm from the left and right edges of the sheet, and the other side is on the outside by about 5 mm from the left and right edges of the sheet. It is generally preferred that Accordingly, the width of the ink discard groove for the left and right ends and the position of the sheet support portion are set so as to satisfy the positional relationship as described above for various types of standard sheets. However, the positional relationship between the left and right sides of the ink discard groove for the left and right edges and the left and right edges of the sheet is not limited to the above dimensions (2 mm, 5 mm), and other dimensions may be selected as necessary. Good. Note that instead of the center reference, sheets having various sheet widths may be used as a one-side reference that aligns the left and right reference positions.

  Assuming that borderless printing is performed on the four sides of the cut sheet in this way, the sheet support portion 14 of the platen 9 has the leading and trailing edge ink discarding grooves 31A and 31B, and the left and right edge ink discarding grooves of the sheet. 34, and is in an isolated form. In addition, in each of the ink discarding grooves 31A, 31B, and 34, an ink absorber as shown in FIGS. 6 and 7 is used in order to suppress the occurrence of mist due to the rebound at the time of landing of the ink and the leakage of the discarded ink. 35 is arranged. The ink absorber 35 is preferably composed of a single sponge-like sheet such as urethane foam. Further, the upper surface of the ink absorber 35 is locked by locking claws 38 (see FIG. 7) as a plurality of locking members, and is prevented from falling off the platen 9.

  Here, as shown in FIGS. 16 and 17, the ink absorber 35, the platen 9, and the locking claw 38 are close to each other. For this reason, the ink discarded on the surface of the ink absorber 35 may leak to the outside of the platen 9 through the gap 44 between the platen 9 and the locking claw 38 due to a capillary phenomenon. In order to prevent this, it is desirable to fill the gap 44 between the platen 9 and the locking claw 38 with a sealing material or to apply a water repellent such as water repellent grease.

  Further, as shown in FIGS. 18 and 19, portions of the side wall surfaces 31 b and 31 e of the platen 9 that are close to the locking claws 38 are formed as concave portions 31 h that are separated from the ink absorber 35. By forming the recess-shaped portion 31h in this way, the ink discarded on the surface of the ink absorber 35 does not reach the gap 44 between the platen 9 and the locking claw 38, so that the platen 9 is exposed to the outside due to capillary action. Ink leakage can be prevented. Further, by separating the portion of the locking claw other than the portion that locks the ink absorber upward from the ink absorber and the platen, a capillary phenomenon does not occur between the locking claw and the platen. A gap may be formed. However, the locking claw needs to have a height and shape that do not hinder the conveyance of the sheet.

  Further, as shown in FIG. 8, a downstream side waste ink flow path 31f1 for flowing waste ink that has passed through the ink absorber 35 is provided on the bottom surface 31a of the tip ink discarding groove 31A. Similarly, an upstream side waste ink flow path 31f2 for flowing waste ink that has passed through the ink absorber 35 is provided on the bottom surface 31a of the rear end ink discarding groove 31B. As shown in FIG. 9, the bottom surface 31f1a of the downstream side waste ink flow path 31f1 is a slope inclined downward from both ends in the X direction toward the center. Although not particularly illustrated, the bottom surface of the upstream side waste ink flow path 31f2 is also a slope inclined downward from both ends in the X direction toward the center. Further, the downstream waste ink accumulation portion 31g1 is provided at the lowest portion of the bottom surface of the downstream waste ink flow passage 31f1, and the upstream waste ink accumulation portion 31g2 is provided at the lowest portion of the bottom surface of the upstream waste ink flow passage 31f2. (See FIG. 8). Here, the downstream side waste ink accumulation portion 31g1 is formed at a position lower than the upstream side waste ink accumulation portion 31g2.

  An intermediate waste ink flow path 31f3 is formed between the two sheet support portions 14A and 14B located at the center in the longitudinal direction (X direction) of the platen 9. The intermediate waste ink flow path 31f3 connects the above-described two waste ink accumulation portions 31g1 and 31g2, and from the connection position with the upstream waste ink accumulation portion 31g2 toward the downstream waste ink accumulation portion 31g1. It has a bottom surface that is inclined downward.

  Since it is configured as described above, the ink discarded on the ink absorber is finally collected in the downstream side waste ink accumulation unit 31g1. For example, the waste ink discarded in the rear end ink discard groove 31B is temporarily received by the ink absorber 35 and falls from the ink absorber 35 to the upstream side waste ink flow path 31f2. Then, it is collected in a central waste ink collecting portion 31d2. The waste ink collected in the waste ink accumulation part 31d2 flows through the inclined bottom surface of the intermediate waste ink flow path 31f3 as shown by a broken line arrow C in FIG. 8, and finally reaches the downstream side waste ink accumulation part 31d1. Reach. Further, the waste ink discarded in the leading edge ink discarding groove 31A and the left and right end ink discarding grooves 34 is once received by the ink absorber 35 and falls downward from the ink absorber 35. And it collects in the downstream waste ink accumulation | storage part 31d1.

  The bottom surface 31a, which is the slope of each of the waste ink flow paths 31f1, 31f2, 31f3, is provided with a fine concavo-convex portion that is elongated along the slope. The capillary force generated in the uneven portion promotes the flow of waste ink to the waste ink accumulation portions 31d1 and 31d2.

  The platen 9 is provided with a sheet support portion 14 including the suction holes 18 and an outer peripheral wall 20 surrounding the ink discarding groove 31, and a casing (platen casing) is formed by the outer peripheral wall 20. Further, a waste ink discharge port 30 communicating with the downstream waste ink accumulation portion 31g1 is provided on a side portion of the outer peripheral wall 20, and the waste ink collected in the waste ink accumulation portion 31g1 is disposed in the waste ink discharge port 30. To the outside of the platen 9.

3. Sheet Adsorption Mechanism FIG. 10 is a vertical side view showing the sheet adsorption mechanism provided in the printing apparatus. The sheet suction mechanism includes a platen 9, a duct 27 that communicates with a suction hole 18 formed in the platen 9, and a negative pressure generating unit that communicates with the duct 27.

  Immediately below the platen housing formed by the outer peripheral wall 20 of the platen 9, a cover member 23 having a first opening 23a on the upper surface and a base member 24 having a second opening 24a on the lower surface are configured. A duct 27 having a hollow inside is provided. The upper part of the cover member 23 is engaged with the bottom side of the outer peripheral wall 20 of the platen 9 so that the first opening 23a is included. The second opening 24a provided on the lower surface of the base member 24 is engaged with the suction port 19a of the suction fan 19 which is a negative pressure generating means. As a result, an intake flow path 36 extending from the suction hole 18 of the platen 9 to the suction fan 19 is formed.

  The intake flow path 36 is formed in a duct 27 composed of a first negative pressure chamber 22 corresponding to a space in the platen casing formed by the outer peripheral wall 20 of the platen 9, and the base member 24 and the cover member 23. The second negative pressure chamber 25 is configured. The base member 24 forming the duct 27 is fixed to the chassis 28.

  The first negative pressure chamber 22 corresponds to each of the plurality of sheet support portions 14 and is an independent small space partitioned into a plurality in the sheet width direction. FIG. 10 illustrates one small space. The first negative pressure chamber 22 and the second negative pressure chamber 25 are partitioned by a cover member 23, and the common second negative pressure chamber 25 is divided into a plurality of first negative pressure chambers 22. It communicates through the small space opening 23a.

  Here, the downstream side waste ink flow path 31f1 and the upstream side waste ink flow path 31f2 are provided adjacent to the downstream and upstream of the second negative pressure chamber 22, respectively. For this reason, a platen that is compact and highly integrated with no waste in spatial arrangement is realized.

  Air leaks to the engaging portion between the upper surface of the cover member 23 and the bottom of the outer peripheral wall 20 of the platen 9, and the engaging portion between the second opening 24a of the base member 24 and the suction port 19a of the suction fan 19, respectively. A seal member 26 for preventing the above is disposed. The seal member 26 is preferably made of foamed rubber or the like made of EPDM that is soft and has high sealing properties so that the platen 9 and the cover member 23 are not deformed by the repulsive force when compressed. By interposing the seal member 26 between the members, it is possible to suppress the drive vibration of the suction fan 19 from being transmitted to the platen 9 while maintaining the sealing property between the members, and to the printing operation. The influence of can be suppressed.

  Further, the waste ink discharge port 30 of the platen 9 is provided on the outer peripheral wall 20 of the platen 9 so as to discharge toward the side. For this reason, the duct 27 arranged immediately below the platen 9 can occupy the space directly below the platen 9 without being obstructed by the arrangement of the waste ink discharge port 30. In the second negative pressure chamber 25 of the duct 27, it is possible to secure a sufficient size to stabilize the negative pressure generated by the rotation of the suction fan 19, and the degree of freedom in design is greatly improved.

  The suction fan 19 as the negative pressure generating means is preferably a sirocco fan having a high suction efficiency. The suction fan 19 can adjust the suction air volume by PWM control. By making the air volume variable depending on the type of sheet, the state of the sheet, and the use atmosphere environment, the adsorptivity of the sheet can be adjusted.

  In the above configuration, by rotating the suction fan 19 and discharging the air in the duct 27, the entire intake passage 36 is in a negative pressure state, and air can be sucked from the suction hole 18 communicating with the duct 27. it can.

  The platen 9 is manufactured as one part by a resin mold. The plurality of sheet support parts 14, the upstream sheet support part 32, the downstream sheet support part 33, the first negative pressure chamber 22, the ink receiving part, and the waste ink flow path are all in one resin mold part constituting the platen 9. It is formed by aggregation. This simplifies the manufacturing of the printing apparatus and improves the relative positional accuracy of the functional units.

4). Waste Ink Discharge Mechanism FIG. 11 is a perspective view of a tube pump provided in the waste ink discharge mechanism, and FIG. 12 is a plan view showing a waste ink collection path.
The waste ink discharge mechanism includes a tube 16 connected to the waste ink discharge port 30, a waste ink tank 43 connected to the tube 16, and a waste ink pump 15 provided in the middle of the tube 16.

  The tube pump 15 sucks waste ink by pressing the tube 16 against the inner diameter surface of the pump case 21 with a roller 29. The roller 29 is rotatably attached to a rotating roller holder 49. The roller holder 49 is connected to a pump drive motor 107 that is a drive source via a gear train (not shown), and rotates in conjunction with the rotation of the pump drive motor 107.

  Further, the suction port 16 a which is one end of the tube 16 is connected to a waste ink discharge port 30 (see FIG. 8) provided in the outer peripheral wall 20 of the platen 9. The discharge port 16b which is the other end of the tube 16 is connected to a waste ink tank 43 (waste ink storage unit) for finally storing the waste ink.

  When the tube pump 15 is driven in conjunction with the drive of the pump drive motor 107 (see FIG. 13), the waste ink accumulated in the downstream waste ink accumulation portion 31g1 of the platen 9 is discharged to the waste ink discharge port 30 and the tube 16. Then, the ink is discharged to the waste ink tank 43.

  The timing of discharging the waste ink accumulated in the waste ink accumulation portion 31g1 of the platen 9 is when the printing apparatus 1 is powered off or when the amount of ink ejected to the ink absorber 35 exceeds a predetermined threshold. It is desirable to do.

  In addition, as an ink accumulation preventing operation for preventing the printing ink component from accumulating on the surface of the ink absorber 35, a specific ink that easily dissolves the deposit is discharged to the ink absorber 35 after the printing is completed. (See FIG. 20). Depending on the use environment of the printing apparatus 1, a relatively large amount of ink is ejected to the ink absorber 35 to dissolve the deposit (S201). Therefore, immediately after ink ejection, ink is collected on the surface of the ink absorber 35, and the accumulated ink is likely to leak to the outside of the platen 9 through the gap between the platen 9 and the locking claw 38 due to capillary action. Therefore, the tube pump 15 is driven in S202 during the ink accumulation preventing operation, that is, during the ink discharge for dissolving the deposit. Thereby, it is possible to attract the ink discharged to the surface of the ink absorber 35 to the inside of the ink absorber 35 each time, and it is possible to prevent ink from being collected on the surface of the ink absorber 35. After completion of the ink ejection operation for dissolving the deposit (S203), the tube pump 15 is continuously driven (S202 to S204) for a predetermined time (for example, 10 seconds), so that ink is accumulated on the surface of the ink absorber 35. The effect of preventing this is enhanced. Further, the state where ink is accumulated on the surface of the ink absorber 35 occurs after the ink has spread over the entire ink absorber 35. For this reason, the drive control of the tube pump 15 during ink ejection for deposit dissolution may be started after a predetermined period has elapsed since the printing apparatus 1 was started to be used. In addition, the drive control of the above tube pump 15 is performed by CPU101 (refer FIG. 13) in the below-mentioned control system.

  Thus, it is possible to prevent the waste ink from overflowing from the waste ink accumulation portion 31g1 of the platen 9 to the outside of the platen 9, or the waste ink from being dried and fixed in the waste ink flow path 31c or the waste ink accumulation portion 31d. it can.

  Further, as shown in FIG. 12, the waste ink tank 43 is disposed at a position that does not overlap the platen 9 when the apparatus is viewed from above. That is, in the present embodiment, unlike Japanese Patent Application Laid-Open No. 2004-260, a configuration is not adopted in which the waste ink discarded on the platen is discharged directly under the platen using gravity. The waste ink discharge port formed on the side of the peripheral wall 20 of the platen 9 is forced to discharge the waste ink to the waste ink tank 43 located outside the platen 9 by using the tube 16 and the tube pump 15. It is composed. For this reason, the freedom degree of arrangement | positioning of the waste ink tank 43 increases, and it becomes possible to avoid the enlargement of an apparatus by arrange | positioning the waste ink tank 43 in the empty space in the printing apparatus 1. FIG.

  In addition, since the space directly under the platen 9 can be occupied by the duct 27, a sufficient volume can be secured in the duct 27 to stabilize the negative pressure generated by the rotation of the suction fan 19. Further, by providing the duct 27 directly below the platen, the intake passage 36 extending from the suction hole to the suction fan can be simplified and shortened, so that the passage resistance can be reduced and the power consumption of the suction fan 19 can be reduced. It becomes possible to do.

5. Control Circuit FIG. 13 is a block diagram showing a control system configuration of the printing apparatus.
The CPU 101 is connected to a head drive circuit 102 that controls ink ejection of the print head 3. Further, the CPU 101 is connected to a motor drive circuit 103 for controlling motors (carriage motor 104, transport roller motor 105, feed roller motor 106, pump drive motor 107, suction fan 19, etc.) that operate each mechanism. .

  The suction fan 19 is PWM-controlled by the motor drive circuit 103, and can adjust the suction amount of the sheet suction portion by adjusting the air volume. Changing the air volume according to the type of sheet, the state of the sheet, the conditions of the atmospheric environment, etc. is an effective means for adjusting the sheet transportability. It is also possible to change the air volume depending on the position of the carriage 4 and the condition of the sheet conveyance position.

6). Next, a printing operation by the printing apparatus will be described. When a print command transmitted from a host computer (not shown) or the like is transmitted to the printing apparatus 1, the CPU 101 executes the following operation. First, the suction fan 19 is driven to prepare for sucking and supporting the sheet 2 conveyed on the platen 9. Next, the feeding device 40 is driven, and the sheet is fed to the first conveying roller pair including the conveying roller 7 and the pinch roller 8. The first conveying roller pair conveys the sheet fed by the feeding device 40 to a position covering the sheet support surface 13 as shown in FIG. By this conveying operation, the front end 2a of the sheet 2 passes between the sheet support surface 13 and the print head 3, and then is on the front end ink discarding groove 31A and from the most downstream discharge port 3d of the ink discharge nozzle row 3b. Also reaches a position upstream in the Y direction.

  Next, movement of the carriage 4 in the X direction is started, and ink is ejected from the print head 3 to print on the sheet 2. When the printing performed at this time is a so-called borderless print in which no margin is formed at the edge of the sheet 2 and an image is formed on the entire sheet 2, ink is ejected to an area extending from the outside to the inside of the sheet 2. . Here, even if ink is ejected from all of the ejection ports of the ejection port array 3b, the most downstream ejection port 3d is located upstream from the leading-edge ink discarding groove 31A, and hence is ejected to the outside (downstream side) of the sheet 2. All ink is received by the ink absorber 35. Further, since the left and right side edges of the sheet are also positioned on the left and right end ink discarding grooves 34 disposed between the sheet support portions 14, all of the ink ejected to the outside of the sheet 2 absorbs ink. It is received by the body 35. Therefore, the ink support surface 13 of the platen 9 is not soiled with ink.

  At this time, the suction fan 19 is rotated to form the sheet support portion 14 through the second negative pressure chamber 25 of the duct 27, the first negative pressure chamber 22 of the platen 9, and the suction hole 18 of the platen 9. The air in the suction recess 17 is discharged. For this reason, a negative pressure is generated in the space from the suction fan 19 to the back surface of the seat 2. Due to this negative pressure, the sheet 2 is adsorbed to the sheet support surface 13, and floating and bending from the sheet support surface 13 are suppressed. Thereby, the distance between the discharge port forming surface 3a of the print head 3 and the sheet 2 is kept constant. In this state, printing on the sheet 2 proceeds by repeating the ejection of ink by the print head 3 and the intermittent conveyance operation of the sheet 2.

  Thereafter, the rear end 2b of the sheet 2 passes through the first conveying roller pair, and as shown in FIG. 15, the front end 2a of the sheet 2 is on the front end side ink discarding groove 31 and more than the most upstream discharge port 3c. The final printing operation is performed in a state where the position has reached the downstream position in the Y direction. At this time, even if all the ejection ports of the ejection port array 3b are used, all of the ink ejected to the outside (upstream side) of the sheet 2 is received by the ink absorber 35, and the rear end side of the sheet 2 Borderless printing to the print is completed properly. Thereafter, the sheet 2 is discharged onto the discharge tray 12 by the rotation of the discharge roller 10. When the discharge of the sheet 2 is completed, the driving of the suction fan 19 is stopped by the motor driving circuit 103.

  On the other hand, even in a so-called bordered print that forms a margin along the edge of the sheet 2, the sheet 2 always covers the sheet support surface 13 during printing. For this reason, the sheet 2 is attracted to the sheet support surface 13 by the negative pressure generated in the suction recess 17 formed in the sheet support portion 14, and the floating and bending of the sheet 2 from the sheet support surface 13 are suppressed. Accordingly, even in the case of bordered printing, it is possible to appropriately perform the printing operation while keeping the distance between the discharge port forming surface 3a of the print head 3 and the sheet 2 constant.

  According to the embodiment that has been described above, it is possible to perform printing without a four-sided border on a cut sheet. Then, it is possible to perform proper printing while applying a stable negative pressure to the sheet by the sheet adsorbing mechanism, and it is possible to collect the waste ink ejected on the platen without increasing the size of the apparatus. . That is, it is possible to achieve both reliable waste ink collection and sheet suction with a compact apparatus configuration.

2 Sheet 3 Print head 9 Platen 14 Sheet support part (support part)
15 Tube pump 16 Tube 17 Adsorption recess (recess)
18 Suction hole (suction part)
19 Suction fan 20 Platen outer peripheral wall 27 Duct 30 Waste ink discharge port 31A End ink discarding groove (first ink receiving portion)
31B Rear end ink discard groove (second ink receiving portion)
34 Left and right end ink discard groove (third ink receiving portion)
31f1 1st waste ink flow path 31f2 2nd waste ink flow path 31f3 3rd waste ink flow path 31h Concave shaped part 34 of platen Left and right end ink discarding grooves (third ink receiving part)
35 Ink absorber 43 Waste ink tank 44 Gap between the platen and the locking claw

Claims (18)

A printing apparatus comprising: a print head that ejects ink; and a platen that supports a sheet facing the print head,
The platen is
A support for supporting the sheet;
An ink receiver that receives ink ejected by the print head on the outside of the sheet supported by the support;
A waste ink channel that guides waste ink discharged to the ink receiving portion to a discharge port formed in an outer peripheral wall of the platen;
A printing apparatus, wherein a discharge mechanism for discharging waste ink is connected to the discharge port.   The discharge mechanism includes a waste ink tank that stores waste ink, and a tube that connects the discharge port and the tank, and the waste ink guided to the discharge port is disposed through the tube. The printing apparatus according to claim 1, wherein the printing apparatus is discharged into an ink tank.   The discharge mechanism further includes a pump provided in the middle of the tube, and forcibly discharges the waste ink guided to the discharge port to the waste ink tank through the tube by driving the pump. The printing apparatus according to claim 2, wherein: The ink receiving portion is adjacent to the downstream side of the support portion and receives the ink ejected to the outside of the front end of the sheet; the ink receiving portion is adjacent to the upstream side of the support portion and outside the rear end of the sheet A second ink receiving part for receiving the ink discharged to
2. The waste ink flow path includes a first flow path below the first ink receiving part and a second flow path below the second ink receiving part. 4. The printing apparatus according to any one of items 3 to 3. A plurality of the support portions are arranged side by side along the sheet width direction,
A third ink receiving portion that receives ink ejected from the print head is provided between the adjacent support portions among the plurality of support portions, and is provided below at least one third ink receiving portion. The printing apparatus according to claim 4, wherein a third flow path that connects the first flow path and the second flow path is formed.   The printing apparatus according to claim 5, wherein the first flow path, the second flow path, and the third flow path are inclined so as to collect waste ink toward the discharge port. .   The first ink receiving portion, the second ink receiving portion, and the third ink receiving portion include an ink absorber having an ink receiving surface at a position lower than a position where the support portion supports the sheet. The printing apparatus according to claim 5, wherein the printing apparatus is disposed and the first flow path, the second flow path, and the third flow path are formed under the ink absorber.   The at least one bottom surface of the first groove, the second groove, and the third groove is formed with an uneven portion extending along an inclination of the bottom surface. Item 7. The printing apparatus according to Item 6. Under the support part, a negative pressure chamber for applying a negative pressure to the suction hole provided in the support part is provided,
The printing apparatus according to claim 4, wherein the first flow path and the second flow path are provided adjacent to the negative pressure chamber.   The said support part, the said ink receiving part, and the said waste ink flow path are collectively formed in one resin mold component which comprises the said platen, The any one of Claim 1 thru | or 9 characterized by the above-mentioned. The printing apparatus according to item.   The platen is provided with a plurality of locking members for locking the ink absorber to the first ink receiving portion, the second ink receiving portion, and the third ink receiving portion. The printing apparatus according to claim 7, wherein the printing apparatus is a printer.   The printing apparatus according to claim 11, wherein a sealing material or a water repellent is applied between the platen and the locking member.   In order to prevent ink components from accumulating on the ink absorber, an ink accumulation preventing operation for discharging specific ink from the print head to the ink absorber is performed after completion of printing. The printing apparatus according to claim 1.   The printing apparatus according to claim 3, wherein the ink discharged onto the ink absorber is attracted to the inside of the ink absorber by driving the pump.   The printing apparatus according to claim 3, wherein the pump is driven during the ink accumulation preventing operation.   The printing apparatus according to claim 3, wherein the pump is operated during the ink accumulation preventing operation and until a predetermined time after the operation is completed.   Of the first ink receiving portion and the second ink receiving portion of the platen, a part of the wall surface close to the locking member has a concave shape separated from the ink absorber. The printing apparatus according to claim 1, 7 or 11. A platen disposed opposite to a print head that ejects ink,
A support portion capable of supporting a sheet conveyed from the upstream side to the downstream side of the print head;
A suction unit that applies a negative pressure to the sheet to adsorb the sheet to the support unit;
An ink receiving portion that is provided adjacent to the support portion and receives ink ejected from the print head on the outside of the sheet supported by the support portion;
A platen comprising: a waste ink flow path for guiding ink discharged to the ink receiving portion to a waste ink discharge port formed on an outer peripheral wall of the platen.