JP2012030451A - Inkjet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recorder which has a simple configuration, and enables a printing head to be cleaned at an appropriate timing for each type of a recording medium, thereby preventing clogging of a nozzle hole with powder of recording medium such as paper powder, and which also prevents ejection of useless ink in the cleaning.SOLUTION: The inkjet recorder includes: a storage means for storing a cleaning execution condition preset for each type of a recording medium; and a type acquiring means for acquiring the type of a recording medium to be subjected to printing by the printing head. When the cleaning execution condition corresponding to the type of the recording medium acquired by the type acquiring means, which is stored in the storage means, is established, the printing head is cleaned.

Description

  The present invention belongs to a technical field related to an ink jet recording apparatus including a print head that performs printing by ejecting ink onto a recording medium, and a cleaning unit that cleans the print head.

  In general, in an ink jet recording apparatus, an ink discharge surface, which is a surface where a nozzle hole of a print head opens, is automatically cleaned. As an example of this cleaning method, as shown in Patent Document 1, the print head is moved relative to the wiping member while the flexible wiping member is in contact with the ink ejection surface.

  In such cleaning, usually, the cumulative value of the printing time since the end of the previous cleaning or the cumulative value of the pause time in which the ink ejection surface of the print head is covered with the cap after the end of the previous cleaning is obtained. This is performed when a condition that a predetermined reference time is exceeded is established. Further, in Patent Document 1, cleaning is performed immediately after the apparatus is turned on or when the interrupted print job is started. By such cleaning, ink mist adhering to the ink discharge surface of the print head, drying of the ink discharge surface, and clogging of the nozzle holes due to ink thickening are prevented.

  In addition, for example, as shown in Patent Document 2, an ink ejection abnormality caused by paper dust adhering to the vicinity of a nozzle hole on the ink ejection surface of the print head is detected from the residual vibration pattern of the diaphragm, It is known that when a discharge abnormality is detected, a flushing process or a wiping process using a wiping member is performed. Japanese Patent Application Laid-Open No. H10-228561 discloses a conventional technique for detecting an ink ejection abnormality by detecting a wet state of an ink ejection surface of a print head using an optical sensor.

JP-A-2005-313540 JP 2004-276367 A

  By the way, depending on the type of recording medium on which printing is performed, a large amount of paper dust (recording medium powder) is generated from the recording medium while the recording medium is being transported, and the paper dust is generated on the nozzle holes on the ink ejection surface of the print head. It may adhere to its surroundings. In this case, if the cleaning is performed when a condition such as the cumulative value of the printing time after the end of the previous cleaning exceeds the reference time as in the conventional case, the cleaning is performed depending on the type of the recording medium. There is a possibility that the nozzle hole is clogged before. Therefore, if the reference time is shortened, cleaning is wastefully performed on a recording medium in which paper dust is hardly generated. Here, at the time of cleaning, not only the ink ejection surface of the print head is slid by the wiping member but also ink is forcibly ejected from the nozzle hole, and the paper dust entering the nozzle hole is discharged outside the nozzle hole. It is preferable to perform the recovery operation of clogged nozzle holes, but if the reference time is shortened as described above, useless ink will be ejected on a recording medium in which paper dust is unlikely to occur.

  On the other hand, the discharge abnormality detection method using an optical sensor described as the conventional method of Patent Document 2 has low detection accuracy, and it is particularly difficult to accurately detect adhesion of paper dust. Further, the method of detecting ejection abnormality from the residual vibration pattern of the diaphragm proposed in Patent Document 2 requires a circuit for residual vibration detection and processing for determination, and the circuit and control processing are complicated. .

  The present invention has been made in view of the above points, and an object of the present invention is to make it possible to clean the print head at an appropriate timing for each type of recording medium with a simple configuration, such as paper dust. It is intended to prevent wasteful ink from being ejected during cleaning while preventing nozzle holes from being clogged with recording medium powder.

  In order to achieve the above object, the present invention is directed to an inkjet recording apparatus including a print head that performs printing by discharging ink onto a recording medium, and a cleaning unit that cleans the print head. Storage means for storing cleaning execution conditions set in advance for each type of recording medium, and a type obtaining means for obtaining the type of recording medium printed by the print head, wherein the cleaning means includes: It is assumed that the print head is cleaned when a cleaning execution condition corresponding to the type of the recording medium obtained by the type obtaining means stored in the storage means is satisfied.

  Here, as an operation for cleaning the print head, an operation for sliding the ink discharge surface of the print head by the wiping member (an operation for cleaning the ink discharge surface), or a nozzle hole by forcibly discharging ink from the nozzle hole is performed. There is an operation to recover clogging.

  With the above configuration, the cleaning unit cleans the print head when the cleaning execution condition corresponding to the type of the recording medium obtained by the type obtaining unit stored in the storage unit is satisfied. Cleaning can be performed at an appropriate timing for each type. That is, for recording media that are likely to generate paper dust such as plain paper and postcards, the storage means stores a cleaning execution condition that shortens the cleaning interval, and paper dust such as coated paper. For recording media that are unlikely to occur, if the storage means stores a cleaning execution condition that makes the cleaning execution interval longer, cleaning can be performed at an appropriate timing for each type of recording medium to be printed. Accordingly, it is possible to prevent wasteful ink from being discharged during cleaning while preventing clogging of the nozzle holes due to recording medium powder such as paper powder. Also, storage means for storing the cleaning conditions for each type of recording medium and the type of recording medium to be printed are obtained (for example, obtained by an operator input or obtained by a sensor for determining the type of the recording medium). It is sufficient to simply provide a kind obtaining means.

  In the ink jet recording apparatus, the cleaning execution condition for each type of the recording medium is, for each type of the recording medium, the cumulative perimeter of the recording medium printed by the print head after the end of the previous cleaning. It is preferable that the value is preset with respect to at least one of the value and the cumulative value of the thickness of the recording medium.

  That is, since the recording medium powder is generated from the edge of the recording medium, the larger the accumulated value of the peripheral length of the recording medium printed by the print head or the accumulated value of the thickness of the recording medium after the previous cleaning is finished. There is a possibility that a large amount of recording medium powder is generated and the recording medium powder adheres to the ink discharge surface of the print head or enters the nozzle hole. If a cleaning execution condition is set in advance for the cumulative value for each type of recording medium, cleaning can be performed at a more appropriate timing for each type of recording medium.

  In the case of the cleaning execution condition as described above, the cleaning execution condition for each type of the recording medium is the cumulative value of the peripheral length of the recording medium printed by the print head since the end of the previous cleaning. A condition that a value obtained by multiplying a first coefficient set in advance for each medium type exceeds a first predetermined value, and a cumulative value of the thickness of the recording medium printed by the print head after the end of the previous cleaning. In addition, it is preferable that at least one of the conditions that a value obtained by multiplying a second coefficient set in advance for each type of the recording medium exceeds a second predetermined value.

  As a result, it is possible to easily determine whether or not the cleaning execution condition is satisfied, and the control process is simplified.

  In the ink jet recording apparatus, the cleaning execution condition for each type of the recording medium is a coefficient set in advance for each type of the recording medium in the accumulated value of the scanning time of the print head after the end of the previous cleaning. It may be a condition that the multiplied value exceeds a predetermined time.

  That is, as the cumulative value of the print head scanning time after the end of the previous cleaning is larger, a larger amount of recording medium powder may adhere to the ink ejection surface of the print head or enter the nozzle hole. is there. Then, by adjusting the cumulative value by a coefficient for each type of recording medium, cleaning can be performed at an appropriate timing for each type of recording medium.

  As described above, according to the ink jet recording apparatus of the present invention, the storage means for storing the cleaning execution conditions set in advance for each type of the recording medium and the type of the recording medium printed by the print head are obtained. A type obtaining means, and cleaning the print head when a cleaning execution condition corresponding to the type of the recording medium obtained by the type obtaining means stored in the storage means is established. With a simple configuration, the print head can be cleaned at an appropriate timing for each type of recording medium, and nozzle holes are not clogged with recording medium powder such as paper dust, and wasteful ink is not discharged during cleaning. Can be.

FIG. 2 is a perspective view showing an external appearance of a printer as an ink jet recording apparatus according to an embodiment of the present invention, viewed from an oblique right side on the front side of the printer. It is the schematic seen from the printer right side which shows the internal structure of a printer. FIG. 2 is a schematic diagram illustrating a configuration of a guide unit, in which (a) illustrates a state in which a central guide member is in a use position in order to convey a narrow-sized recording sheet, and (b) illustrates a wide-sized recording sheet. In order to convey, the center guide member is in a non-use position. It is sectional drawing which shows the structure of a recording paper holding part. It is a top view which shows the structure of the platen of a printing part. It is a schematic plan view showing the configuration of a compartment provided on the lower side of the platen, where (a) shows a state in which a narrow-size recording paper passes over the platen, and (b) shows a wide-size recording paper. The state where the recording paper is passing over the platen is shown. FIG. 3 is a schematic view of a main part viewed from the rear side of the printer, showing a positional relationship between a cap part and a print head. It is sectional drawing which shows the structure of a cap part. It is the figure seen from the upper side which cut and shows a cap part partially along a horizontal direction. FIG. 6 is a perspective view illustrating a positional relationship between a cap unit and a print head. It is sectional drawing which shows the principal part of a cap part and a print head, Comprising: (a) shows the state which set the cap member in the contact | adherence position, (b) shows the state which set the cap member in the storing position. FIG. 4 is a schematic view seen from the right side of the printer, showing a state in which the switchback roller pair of the switchback unit receives the recording sheet conveyed from the pair of conveying rollers after cutting and draws it to the rear side of the printer. FIG. 13 is a view corresponding to FIG. 12 showing a state in which the driven rollers of the switchback roller pair are switched to the second position. FIG. 2 is a block diagram illustrating a configuration of a printer control system. It is a flowchart which shows the capping control operation | movement by a capping control part. It is a flowchart which shows the cleaning control operation | movement by a cleaning control part. 4A and 4B are cross-sectional views showing a cap part and a main part of a print head, wherein FIG. 5A shows a state where a wiping member is set at a wiping position, and FIG. 5B shows a state where an ink discharge surface is being cleaned. FIG. 3 is a cross-sectional view of a main part of a cap unit and a print head, showing a state where a wiping member is separated from an ink discharge surface.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an appearance of a printer A as an ink jet recording apparatus according to an embodiment of the present invention. The printer A is used in a photo print system. For example, the printer A obtains image data and order information and performs necessary correction processing from a reception block 200 (see FIG. 14) via a communication cable. The image data transmitted in this manner is printed on the recording paper P (including both a roll-shaped recording paper P and a sheet-shaped recording paper P described later (see FIG. 2)) based on the order information. It is configured.

  In the following description, the side on which a manual feed unit 9 (manual feed tray 102) described later is provided is defined as the front side of the printer, and the opposite side is defined as the rear side of the printer. Further, the left side when viewed from the front side of the printer is defined as the left side of the printer, and the right side is defined as the right side of the printer. The direction perpendicular to the paper surface of FIG. 2 is the left-right direction of the printer, and coincides with the width direction of the recording paper P and a main scanning direction X described later. 2 is the front-rear direction of the printer and coincides with the sub-scanning direction Y described later.

  The printer A includes a housing 3, and inside the housing 3, as shown in FIG. 2, a roll-shaped long recording paper P (magazines M <b> 1 and M <b> 2 described later) provided at the lower portion of the printer A. And a printing unit 2 that prints image data on the recording paper P that is provided at the top of the printer A and is pulled out of the recording paper storage unit 1 and conveyed. It has been. The roll-shaped recording paper P is wound so that the printing surface is on the outside.

  A cutter unit 4 for cutting the printed recording paper P into a predetermined size at the upper part in the housing 3 and on the downstream side in the transport direction of the recording paper P with respect to the printing unit 2, and the cutter unit A switchback unit 5 for switching back the recording paper P after being cut by 4, a back surface printing unit 6 for printing a serial number or the like on the back surface (the surface opposite to the printing surface) of the recording paper P, and recording A drying unit 7 for drying the printing surface of the paper P, and a curl of the roll-shaped recording paper P (curling due to curling when rolled into a roll) is removed and discharged to the outside of the printer A. A decal unit 8 is provided.

  As shown in FIG. 1, on the upper surface of the casing 3 of the printer A, a conveyor device 150 for distributing the recording paper P discharged by the decurling unit 8 to the left or right side of the printer according to its size, and the printer A large-size tray 104 (see FIG. 1) for receiving the large-sized recording paper P distributed on the left side and a normal photo-sized recording paper P such as an L-size distributed on the right side of the printer are received and stacked for each order. And an accumulating device 210 for this purpose. A caster 3 a for moving the entire printer A is attached to the lower surface of the housing 3.

  The recording paper storage unit 1 is positioned almost directly below the printing unit 2 and can store two magazines M1 and M2 for storing the recording paper P. These magazines M1 and M2 are arranged side by side in the vertical direction. In the recording paper storage chambers S1 and S2 in each of the magazines M1 and M2, roll-shaped recording paper P is respectively wound by the winding core R. It is housed in a held state. In the present embodiment, the recording paper storage chamber S1 in the magazine M1 stores a roll-shaped recording paper P having a wide size (for example, a width exceeding 12 inches), and the recording paper storage chamber S2 in the magazine M2. , The roll-shaped recording paper P having a narrow size (for example, a width of 12 inches or less) is accommodated in two rows in the axial direction (the left-right direction of the printer).

  In this embodiment, the printer A includes a manual feed unit 9. The manual feed unit 9 has a manual feed tray 102 on which a sheet-like recording paper P of a predetermined size can be set, and the manual feed tray 102. It has a manual feed roller pair 27 that conveys the set sheet-like recording paper P to the printing unit 2. Thus, the printer A is configured to be able to print on the sheet-like recording paper P. The manual feed tray 102 is supported by the housing 3 so as to be rotatable at the base end portion, and is configured to be extensible and retractable at the distal end side, and is stored along the front side of the printer of the housing 3 with the distal end side shortened. (See FIG. 1) and a use state (see FIG. 2) that protrudes from the printer front side surface of the housing 3 to the printer front side while the front end side is extended. Thus, the storage state is set when the sheet-like recording paper P is not used, and the use state is set when the recording paper P is set for printing on the sheet-like recording paper P.

  The printing unit 2 includes a print head H that performs printing by ejecting ink onto the recording paper P, and a recording paper holding unit D that is provided below the print head H and holds the recording paper P at a printing position. It has.

The print head H is configured to be movable (scanned) along a guide rail (not shown) extending in the main scanning direction X. Specifically, as shown in FIG. 7, the print head H is attached and fixed to the drive belt 12 wound around two pulleys 46 (only one pulley 46 is shown in FIG. 7). One pulley 46 is rotationally driven by the drive motor 11, and the rotational force of the drive motor 11 is transmitted to the drive belt 12 via the pulley 46, whereby the print head H is The print head H has two head units 13 and 13 arranged in the sub-scanning direction Y perpendicular to the main scanning direction X. The head units 13 move in the main scanning direction X along the guide rail. , 13 by ejecting ink from nozzle holes (not shown) provided on the lower surface of the recording paper P, it is possible to print a predetermined image, characters, or the like on the recording paper P. Therefore, the lower surface of each head unit 13 becomes the ink ejection surface 13a.

  In the lower portions of the left and right sides of the housing 3, there are provided cartridge storage portions for detachably storing seven ink cartridges (not shown) in which inks having different hues are sealed. By attaching and detaching these ink cartridges to / from the cartridge housing portions, the used or used ones can be replaced with new ones. The ink cartridge contains yellow, magenta, cyan, black, red, violet, and clear (transparent) inks, respectively.

  In the upper part of the housing 3, there is provided a transport mechanism storage unit 20 that stores a recording paper transport mechanism for pulling out the recording paper P from the recording paper storage unit 1 and transporting it along a predetermined transport path. Yes. The printing unit 2, the cutter unit 4, the switchback unit 5, the back surface printing unit 6, the drying unit 7, and the decurling unit 8 are provided in the transport mechanism housing unit 20, and the recording paper P is placed on the predetermined transport path. Are arranged in this order toward the downstream side in the transport direction.

  Between the printing unit 2 and the recording paper storage unit 1 in the transport mechanism storage unit 20, a guide unit 23, a supply roller 24 and two pressure rollers 24 a and 24 b are part of the recording paper transport mechanism. Is provided. The upstream portion of the guide portion 23 branches into a branch portion 23a on the front side of the printer and a branch portion 23b on the rear side of the printer.

  Here, as described above, the two magazines M1 and M2 are accommodated in the recording paper accommodating portion 1, and when printing is performed on a wide roll-shaped recording paper P, the magazine is accommodated in the magazine M1. The recording sheet P is pulled out from the leading end thereof and is fed out of the magazine M 1 by the magazine roller pair 22 while being guided by the guide roller 21. The recording paper P sent out of the magazine M1 enters the guide portion 23 from the branch portion 23b on the rear side of the printer in the guide portion 23, and is conveyed to the supply roller 24 through the guide portion 23. The guide unit 23 guides the leading end portion of the recording paper P to the supply roller 24 so as not to deviate from the conveyance path, and positions the recording paper P in the width direction as will be described later.

  When printing on a narrow-sized roll-shaped recording sheet P, both or one of the two roll-shaped recording sheets P accommodated in the magazine M2 are pulled out from the leading end thereof, The drawn recording paper P is fed out of the magazine M 2 by the magazine roller pair 22 while being guided by the guide roller 21. The recording paper P fed out of the magazine M2 enters the guide portion 23 from the branch portion 23a on the front side of the printer in the guide portion 23, and is conveyed to the supply roller 24 through the guide portion 23.

  Further, when printing is performed on the sheet-like recording paper P set on the manual feed tray 102, the recording paper P is conveyed to the supply roller 24 by a manual roller pair 27 constituting the recording paper conveyance mechanism. The

  The two pressure rollers 24 a and 24 b are disposed to face each other so as to be pressure-bonded to the supply roller 24. The supply roller 24 is a driving roller, and the pressure rollers 24a and 24b are driven rollers. Then, the recording paper P (wide-sized or narrow-sized roll-shaped recording paper P or sheet-shaped recording paper P) conveyed to the supply roller 24 is between the supply roller 24 and the pressure rollers 24a and 24b. In this state, the paper is supplied to the printing unit 2 by the drive rotation of the supply roller 24. Only one of the two pressure rollers 24a and 24b may be provided.

  The recording paper P supplied to the printing unit 2 by the driving rotation of the supply roller 24 is supplied (conveyed) to the printing unit 2 located on the downstream side in the conveyance direction of the recording paper P with respect to the supply roller 24 for printing. Printing is performed on the recording paper P by the print head H in the section 2.

  The printed recording sheet P after printing is sent to the cutter unit 4 by the post-printing conveyance roller pair 25 and is cut into a predetermined size by the fixed blade 4a and the movable blade 4b of the cutter unit 4. The cut recording paper P is conveyed to the rear side of the printer by the three sets of post-cutting conveyance roller pairs 26 and then delivered to the switchback unit 5. Here, with respect to the sheet-like recording paper P, margins at the leading edge and the trailing edge of the recording paper P are cut by the cutter unit 4 when finishing the borderless printing. The three pairs of post-cut conveyance roller pairs 26 are configured to be switchable between a pressure-bonded state in which they are pressed against each other and a pressure-released state in which the pressure bonding is released, and the recording paper P is delivered to the switchback unit 5. After that, the pressure bonding is released to prepare for receiving the recording paper P to be conveyed next.

  In the switchback unit 5, after the cut recording paper P is received from the leading end side and pulled to the rear side of the printer by the switchback roller pair 173, this time, the trailing end of the recording paper P is set to the top and the transport direction is changed. The recording paper P is discharged from the horizontal direction to the vertical direction (from the left-right direction in FIG. 2 to the up-down direction).

  The recording paper P discharged from the switchback unit 5 is sent to the back surface printing unit 6 by the supply roller pair 175, and a serial number is printed on the back surface of the recording paper P (corresponding to the front surface of the recording paper P on the printer). Then, it is conveyed to the drying unit 7.

  In the drying unit 7, the printing surface (corresponding to the surface on the rear side of the printer of the recording paper P) is dried while the recording paper P is transported by the three pairs of transport rollers 28. The recording paper P that has been dried is sent to the decurling unit 8 by the conveying roller pair 29.

  In the decurling unit 8, in order to remove curling of the recording paper P wound in a roll shape (curling due to curl when rolled up in a roll shape), the recording paper P is driven by a driving conveyance roller 81 and a decurling roller 82. 2, the decurling roller 82 is moved in the clockwise direction in FIG. 2 along the outer peripheral surface of the driving conveyance roller 81 from a position directly above the driving conveyance roller 81. As a result, the recording paper P is decurled while being bent in a direction opposite to the curling direction, and is discharged from the discharge port 90 formed in the housing 3 onto the conveying belt 151 (see FIG. 1) of the conveyor device 150. Discharged. In the case of the sheet-like recording paper P, the decurling roller 82 is positioned immediately above the driving conveyance roller 81 (a conveyance position described later), and the decurling process is performed on the sheet-like recording paper P. It is not made.

  Hereinafter, each component of the printer A will be described in detail.

  The recording paper storage unit 1 is provided with a slide base 30 on which the magazines M1 and M2 are placed. The slide table 30 is configured to be slidable in the front-rear direction of the printer by linear guides (not shown) provided on both left and right sides and extending in the front-rear direction of the printer. Thus, the magazines M1 and M2 can be taken out from the case 3 or put into the case 30 by sliding the slide base 30 in the front-rear direction of the printer. The front surface of the slide table 30 is covered with a door member 31 that forms a part of the housing 3 and can be opened and closed. By opening the door member 31, the recording paper P can be replaced. It is like that.

  The magazines M1 and M2 are substantially hermetically sealed box-type containers configured to be portable. An opening for drawing out the recording paper P stored in the magazines M1 and M2 to the outside of the magazines M1 and M2 at the front end of the magazines M1 and M2 in the state of being set in the recording paper storage unit 1 111 is formed. The opening 111 has a substantially rectangular shape extending in the printer left-right direction (magazine length direction). The magazines M1 and M2 are provided with an opening / closing shutter mechanism (not shown) for opening and closing the opening 111. The opening / closing shutter mechanism is of a motor drive type, and opens the opening 111 when the magazines M1 and M2 are set in the recording paper storage unit 1 and opens the opening 111 when taking out from the recording paper storage unit 1. 111 is closed. Further, when the printer A is not operated for a long time, the air in the magazines M1 and M2 is prevented from drying by closing the opening 111, and the recording paper P in the magazines M1 and M2 is cracked. Make sure that does not occur.

  The magazine roller pair 22 provided in the recording paper storage chambers S1 and S2 in the magazines M1 and M2 is a pressure-bonding roller pair including a magazine driving roller 32 and a magazine driven roller 33.

  In the magazine M2 in which the narrow-sized recording paper P is accommodated, the magazine driven roller 33 is constituted by a single cylindrical roller, whereas the magazine driving roller 32 has a left divided roller and a right divided roller. Two cylindrical rollers are arranged in series (coaxially). The left and right divided rollers constituting the magazine drive roller 32 are connected to separate motors and can be driven independently. One of these two motors is also used as a drive source for the magazine drive roller 32 provided in the magazine M1.

  The left and right split rollers constituting the magazine drive roller 32 in the magazine M2 are set to a length corresponding to the width of each of the left and right recording sheets P accommodated in the magazine M2. When both the left and right rows of recording paper P stored in the magazine M2 are pulled out, both the left and right divided rollers are driven by the respective motors. Further, when only one of the two rows of recording paper P accommodated in the magazine M2 is pulled out, only the division roller corresponding to the one recording paper P is driven by the motor corresponding to the division roller. When pulling out the wide-sized recording paper P stored in the magazine M1, the magazine driving roller 32 disposed in the magazine M1 is driven by one motor. At this time, the connection between the one motor and the magazine driving roller 32 in the magazine M2 is disconnected.

  Thus, in this embodiment, the magazine drive roller 32 in the magazine M2 is comprised by two division | segmentation rollers, and each division | segmentation roller can be independently driven by a respectively different motor. Therefore, as described above, by controlling the driving of the left and right divided rollers constituting the magazine driving roller 32, only the necessary recording paper P among the recording papers P in the magazine M2 can be selectively pulled out. .

  The supply roller 24 is composed of a single cylindrical roller. In the present embodiment, the outer diameter of the supply roller 24 is equal to the outer diameter of each magazine drive roller 32. The supply roller 24 is driven by a motor (not shown) different from the motor that drives the magazine drive roller 32, and rotates in the forward direction to pull out the recording paper P from the recording paper storage unit 1 and convey it to the printing unit 2 side. The recording paper P is configured to be switchable to reverse rotation for returning the recording paper P into the recording paper storage unit 1. The same applies to the magazine drive roller 32 of the magazine roller pair 22. Thereby, for example, in the case where printing is performed by changing from the narrow size recording paper P to the wide size recording paper P, or in the case where printing is performed by changing from the roll-shaped recording paper P to the sheet-shaped recording paper P. Then, after the printed portion of the roll-shaped recording paper P (long recording paper P) is cut into a predetermined size by the cutter unit 4, the unprinted portion of the recording paper P is placed in the recording paper storage unit 1. Can be returned.

  As shown in FIG. 3, the guide unit 23 includes a pair of left and right guide members 41 and 42 arranged at a predetermined interval (interval corresponding to the width of the wide size recording paper P) in the left and right direction of the printer, and both guide members. And a central guide member 43 disposed between 41 and 42.

  The left and right guide members 41, 42 have a U-shaped cross section and are arranged so that the opening sides face each other. The left and right guide members 41 and 42 are disposed so as to be bilaterally symmetric with respect to the printer center surface 95 passing through the center of the platen 45 in the main scanning direction X. When printing on a wide-sized recording sheet P, the both ends in the width direction of the recording sheet P are conveyed while being inserted into the grooves 41a and 42a of the guide members 41 and 42, respectively. As a result, the position of the recording paper P in the width direction is restricted, and the recording paper P can be prevented from shifting in the width direction from a predetermined transport path.

  The central guide member 43 is supported by a feeding mechanism (not shown) (for example, a ball screw mechanism), and is used on the substantially same surface as the conveyance surface of the recording paper P (position shown in FIG. 3A). It is configured to be movable between a non-use position (position shown in FIG. 3B) that is located on the front side of the printer from the conveyance surface of the recording paper P.

  The central guide member 43 is formed of a substantially rectangular parallelepiped member, and a surface passing through the center in the width direction of the central guide member 43 coincides with the printer central surface 95. The central guide member 43 has a substantially H-shaped cross section perpendicular to the longitudinal direction thereof, and groove portions 43 a having a U-shaped cross section are formed on both left and right side surfaces of the central guide member 43.

  When printing on the narrow-sized recording paper P, the central guide member 43 is moved to the use position by the feeding mechanism. As a result, among the both ends in the width direction of the recording paper P, the end portion located on the printer central surface 95 side is conveyed while being inserted into the groove portion 43 a of the central guide member 43. During this conveyance, the end portion of the recording paper P located on the side opposite to the printer central surface 95 side is guided by the left and right guide members 41 and 42. As a result, the position in the width direction of the narrow size recording paper P can be regulated. On the other hand, when printing on a wide size recording paper P, the central guide member 43 is moved to the non-use position by the feeding mechanism, and the width direction position of the recording paper P is the left and right guide members 41 and 42. It will be regulated by.

  The printing unit 2 includes a print head driving mechanism including the guide rail, the driving motor 11, the driving belt 12, and the pulley 46, the recording paper holding unit D, and the recording paper P with respect to the recording paper holding unit D. A press-type post-printing conveyance roller pair 25 (see FIG. 2) is provided on the downstream side in the conveyance direction. Here, the main scanning direction X corresponds to the width direction (printer left-right direction) of the recording paper P, and the sub-scanning direction Y corresponds to the conveyance direction (printer front-back direction) of the recording paper P.

  Two head units 13 are provided on the bottom surface of the print head H (a surface facing a recording paper holding portion D described later) side by side in the sub-scanning direction Y. A plurality of nozzle holes (not shown) are formed in the lower surface of each head unit 13 so as to form a line in the sub-scanning direction Y.

  All the head units 13 have the same configuration, and each has a plurality of nozzle arrays disposed in the main scanning direction X for ejecting ink of each color. In each nozzle array, nozzle holes are arranged in a row in the sub-scanning direction Y. Accordingly, each head unit 13 is configured to be able to form a color image by itself.

  Here, the configuration of each head unit 13 is not particularly limited, but each head unit 13 in the present embodiment is a pressure chamber filled with ink (provided separately for each nozzle hole). A general piezo type that ejects ink from a nozzle hole communicating with a pressure chamber is adopted by changing the volume of the inside by a piezoelectric element (piezo element). The number of head units 13 is not necessarily two, and may be one or three or more.

  The recording paper P on the recording paper holder D is intermittently (stepped) at a constant unit conveyance amount by a supply roller 24 provided on the upstream side of the recording paper P in the conveyance direction of the recording paper P with respect to the recording paper holder D. ) When the recording paper P is conveyed in the sub-scanning direction Y, and the recording paper P is stopped during this intermittent conveyance, the print head H is scanned one time (one-way operation or one-time operation) in the main scanning direction. Ink is ejected from the nozzle holes of each head unit 13 at each position in the direction. That is, after one scan of the print head H, the recording paper P is transported by the unit transport amount, and then the print head H is scanned once again, and this operation is repeated to print a desired image on the recording paper P. Will be.

  As shown in FIGS. 4 and 5, the recording paper holding portion D has a plurality of suction holes 60 opened on the surface (upper surface) corresponding to the print area of the print head H, and corresponds to the flushing area. The platen 45 in which the flushing hole 61 is formed, the space 62 provided below the print area of the platen 45 by the print head H and communicating with the suction hole 60, and the suction hole 60 by sucking and exhausting air in the space 62. And a suction fan (not shown) that generates a negative pressure on the surface of the platen 45 and sucks and holds the recording paper P on the surface of the platen 45. Below the space 62, there is formed a device accommodating space 65 in which a suction fan and an opening / closing mechanism 64 described later are accommodated.

  The space 62 is partitioned into a plurality of (six in this embodiment) compartments 66 by partitions arranged in the main scanning direction X (see FIG. 6). A communication hole 67 that communicates with the device accommodating space 65 is formed on the lower surface of each compartment 66. Each communication hole 67 of each compartment 66 is provided with an open / close plate 67a. Each opening / closing plate 67a is configured to be able to open / close each communication hole 67 by rotating around a support shaft 68 extending in the main scanning direction X.

  Each open / close plate 67a is biased clockwise in FIG. 4 around the support shaft 68 by a biasing spring (not shown), and is opened and closed by an open / close mechanism 64 housed in the device housing space 65. The opening / closing mechanism 64 includes a cam shaft 69 extending in the main scanning direction X, six rotating plate cams 70 (only four of which are shown in FIG. 4) attached to the cam shaft 69, and a cam shaft. And a cam drive motor (not shown) for rotationally driving 69.

  The six rotary plate cams 70 are arranged at a predetermined interval in the main scanning direction X corresponding to the position of each opening / closing plate 67a. Each rotary plate cam 70 has an arcuate cam surface. The shape (cam profile) of the cam surface of each rotating plate cam 70 is set so as to realize a selective opening / closing operation of an opening / closing plate 67a described later.

  When the cam shaft 69 is rotationally driven by the cam drive motor, the cam surface of the predetermined rotating plate cam 70 comes into contact with the cam contact surface 67b of the opening / closing plate 67a according to the rotation angle of the cam shaft 69, The opening / closing plate 67a is pushed up. As a result, the open / close plate 67 a rotates upward (counterclockwise in FIG. 4) about the support shaft 68 and closely contacts the sealing material 71 provided along the peripheral edge of the communication hole 67. Thus, the communication hole 67 is closed by the opening / closing plate 67a. Since the suction force of the suction fan does not act on the compartment 66 in which the communication hole 67 is closed, the suction force of the suction fan acts on the compartments 66 other than the compartment 66 in a concentrated manner.

  In the present embodiment, paying attention to this, according to the width dimension of the recording paper P, the suction force is not applied to the unnecessary suction holes 60 (the suction holes 60 not covered by the recording paper P). By selectively closing the communication holes 67, the suction force of the suction fan is concentratedly applied to the necessary suction holes 60 (the suction holes 60 covered with the recording paper P), so that the recording paper The flatness of P is ensured.

  Specifically, as shown in FIG. 6, when printing is performed on the recording paper P on the left side of the printer among the two rows of recording paper P accommodated in the magazine M <b> 2, the right side of the printer among the six compartments 66 is used. In other words, the communication holes 67 of the three compartments 66 located on the side opposite to the side on which the recording paper P passes are closed by the opening / closing plate 67a. Similarly, when printing on the recording paper P on the right side of the printer, the communication holes 67 of the three compartments 66 located on the left side of the printer are closed by the opening / closing plate 67a (see FIG. 6A). Further, when printing on the wide size recording paper P accommodated in the magazine M1, the communication holes 67 of the compartments 66 located at both ends in the left-right direction of the printer among the six compartments 66 are formed by the opening / closing plates 67a. It closes (see FIG. 6B). On the other hand, when printing is simultaneously performed on two rows of recording paper P, all the opening / closing plates 67a are opened, and all the communication holes 67 of the six compartments 66 are opened.

  Such a selective opening / closing operation of the opening / closing plate 67a is realized by controlling the rotation phase of the cam drive motor by a conveyance control unit 202 described later. In this embodiment, the opening / closing plate 67a is rotated around the support shaft 68 so that the suction force of the suction fan does not act on the unnecessary suction holes 60. For example, the lower surface (back surface) of the platen 45 is used. Alternatively, a plurality of opening / closing plates 67a arranged in the main scanning direction X may be provided, and each opening / closing plate 67a may be slid in the sub-scanning direction Y.

  The flushing hole 61 is for receiving ink ejected from the nozzle hole of the print head H by a flushing process at the start of printing or the like in order to prevent the ink from thickening. An ink absorbing member (not shown) that absorbs the ejected ink is accommodated. The ink discharged to the flushing hole 61 is collected by the collection unit 358 (see FIG. 8) through the waste pipe. The flushing hole 61 is formed at the left end of the platen 45 (see FIG. 5). In FIG. 5, the upper side of the figure corresponds to the front side of the printer, the lower side of the figure corresponds to the rear side of the printer, the left side of the figure corresponds to the right side of the printer, and the right side of the figure corresponds to the left side of the printer.

  As shown in FIG. 5, a recess 45 c extending in the sub-scanning direction Y is formed on the support surface 45 a (upper surface) that supports the recording paper P of the platen 45. An ink absorbing member 72 is accommodated in the recess 45c. When the ink absorbing member 72 performs borderless printing for printing an image on the entire recording paper P, a part of the ink ejected from the print head H (head unit 13) is the width of the recording paper P on the support surface 45a. This is provided in order to prevent the support surface 45a of the platen 45 from being soiled by the ink that has come off from the outer edge of the direction. For this reason, the concave portion 45c extends along the edge at a position corresponding to the edge in the width direction of the recording paper P on the support surface 45a on the support surface 45a and a position corresponding to the print head H in the sub-scanning direction Y. (That is, extending in the sub-scanning direction Y).

  In the printing unit 2, the print head H waits at a position outside the print area of the print head H in the main scanning direction X (on the left side of the printer of the platen 45) when printing is not being performed. The cap portion 52 (see FIGS. 7 to 11) is provided below the print head H located at the standby position. In FIG. 7, the left side of the drawing corresponds to the right side of the printer, and the right side of the drawing corresponds to the left side of the printer.

  As shown in FIGS. 7 to 11, the cap portion 52 includes a main frame 331, a plate-like shift member 332 provided so as to be movable in the vertical direction with respect to the main frame 331, and the shift member 332. And a wiping mechanism W and a capping mechanism C supported on the upper surface side of the shift member 332. The entire periphery of the peripheral edge of the shift member 332 is bent downward along a frame-like side wall 333 attached to the main frame 331.

  The shift member drive mechanism V includes a stepping motor type shift motor 335 supported by the main frame 331, a wheel gear 336 supported on the side wall 333, a pinion gear 337 rotating integrally with the wheel gear 336, A rack gear 338 is attached to the shift member 332 in mesh with the pinion gear 337, and a worm gear 339 is rotated with driving force from the shift motor 335 in mesh with the wheel gear 336.

  The side wall 333 is provided with a photo-interrupt type upper position sensor 301 and a lower position sensor 302, which are composed of a light source and a light receiving element, so as to be positioned vertically. At the end of the shift member 332, when the shift member 332 moves upward, the light beam from the upper position sensor 301 is shielded before reaching the upper movement end, and when the shift member 332 moves downward, A light shielding piece 340 that shields the light beam of the lower position sensor 302 before reaching the moving end on the side is provided.

  From the structure of the shift member drive mechanism V and the structure of the upper position sensor 301 and the lower position sensor 302, the shift member 332 is moved upward by rotating the shift motor 335 in one direction (forward rotation). The shift member 332 can be moved downward by rotating the shift motor 335 in the other direction (reverse rotation). When the shift member 332 is moved upward, the upper position sensor 301 outputs a detection signal. By driving the shift motor 335 by an amount corresponding to a preset number of pulse signals on the basis of the output timing, an amount corresponding to the number of pulse signals is higher than the height position of the upper position sensor 301. In contrast, when the shift member 332 is moved downward, By driving the shift motor 335 by an amount corresponding to a preset number of pulse signals with reference to the timing at which the part position sensor 302 outputs the detection signal, the pulse signal is higher than the height position of the lower position sensor 302. The shift member 332 is positioned on the lower side by an amount corresponding to the number of.

  Two resin holders 345 are fixed on the upper surface of the shift member 332 so as to be aligned in the sub-scanning direction Y. In each holder 345, the 1st and 2nd accommodating parts 345a and 345b are provided. A wiping member 346 made of a flexible material such as soft resin or rubber is accommodated in the first accommodating portion 345a so as to be movable in the vertical direction. The wiping member 346 is urged upward by a compression coil spring 347 accommodated in the first accommodating portion 345a. Each wiping member 346 cleans the ink ejection surface 13a (the lower surface where the nozzle holes are opened) of each head unit 13 of the print head H. The length of each wiping member 346 in the sub-scanning direction Y is formed in a plate shape longer than the length of each head unit 13 of the print head H in the sub-scanning direction Y. Each wiping member 346 is integrally formed with a pressing portion abutting portion 346a with which a lower surface of a pressing portion 325 (described later) of the print head H abuts.

  A cap member 350 is accommodated in the second accommodating portion 345b of each holder 345 so as to be movable in the vertical direction. Similarly, the cap member 350 is urged to protrude upward by a compression coil spring 351 housed in the second housing portion 345b. The cap member 350 is formed with two concave portions 350a that open upward, and lips 350b made of a flexible material such as soft resin or rubber are formed around the openings of the two concave portions 350a. Absorbers 352 made of porous resin (sponge or the like) that absorbs ink are disposed in the recesses 350a. Each cap member 350 is in close contact with the ink ejection surface 13a of each head unit 13 when the print head H is not used. Each cap member 350 is supported by each holder 345 so that its posture can be changed. Even if the relative posture between the ink discharge surface 13a of each head unit 13 and each cap member 350 is changed slightly. Each cap member 350 (lip 350b) is configured to be in close contact with the ink ejection surface 13a of each head unit 13.

  Each cap member 350 is connected to a decompression tube 353 and an air supply tube 354 so as to communicate with the space in each recess 350a of the cap member 350 from the bottom surface side. The decompression tube 353 is connected to a suction pump 355 that discharges air and ink in each recess 350 a, and the suction pump 355 is driven by a pump motor 356. By the operation of the suction pump 355, the ink in each recess 350 a is collected by the collection unit 358 via the decompression tube 353. The air supply tube 354 is connected to an electromagnetic valve 357 that switches between supply and non-supply of air into each recess 350a.

  A pair of arms 361 are supported on the side walls 333 on both sides in the sub-scanning direction Y so as to be swingable (turnable) around the support shaft 360. Both ends of a blade 362 extending in the sub-scanning direction Y are connected to one end (upper end) of the pair of arms 361. A contact portion 361a is formed at the other end (lower end) of both arms 361, respectively. Both arms 361 are biased by one torsion coil spring 364 in the tilting direction (counterclockwise direction in FIG. 11A), and the contact portion 361a of both arms 361 is in the sub-scanning direction of the shift member 332. The abutting pins 363 provided on both sides of Y are in contact with each other so that they cannot swing any further. When the shift member 332 is moved downward, as shown in FIG. 11B, the contact pin 363 presses the contact portion 361a of the arm 361, and the biasing force of the torsion coil spring 364 is exerted. The arm 361 is counteracted and swung in the direction in which the arm 361 stands (clockwise in FIG. 11B). As a result, the blade 362 is brought into sliding contact with the distal end portion of the wiping member 346, and the adhered matter adhering to the distal end portion is removed. On the other hand, when the shift member 332 is moved upward, as shown in FIG. 11A, the biasing force of the torsion coil spring 364 causes the arm 361 to swing in the falling direction so as to follow the contact pin 363. Move. As a result, the blade 362 retracts from the tip of the wiping member 346 (also retracts from the tip of the pressing portion contact portion 346a).

  FIG. 11A shows a state in which each cap member 350 is set at a close position where it is in close contact with the ink discharge surface 13a of each head unit 13. Thus, in order to bring the cap members 350 into close contact with the ink ejection surfaces 13a of the head units 13, with the print head H set at the standby position, the shift motor 335 is rotated forward to move the shift member 332 upward. By moving, each cap member 350 is moved to the contact position. That is, from the timing at which the upper position sensor 301 outputs the detection signal, the shift motor 335 is driven by an amount corresponding to a preset number of pulse signals, and then stopped. When each cap member 350 is in close contact with the ink discharge surface 13a of each head unit 13, the lip 350b of each cap member 350 is elastically deformed, and the ink discharge surface 13a (nozzle hole) is sealed with the cap member 350. It becomes.

  In the state where each cap member 350 is in close contact with the ink ejection surface 13a of each head unit 13, the pressing portion 325 formed on the print head H presses the pressing portion abutting portion 346a of the wiping member 346. The protruding amount of the wiping member 346 is reduced so that the wiping member 346 does not come into contact with the print head H or a component provided on the print head H.

  FIG. 11B shows a state in which each cap member 350 is set at a storage position located below the contact position. In this state, the shift member 332 is closest to the main frame 331. In order to operate the shift member 332 to the retracted position, the shift motor 335 is reversely rotated to move the shift member 332 downward, and the number of pulse signals set in advance from the timing when the lower position sensor 302 outputs the detection signal. After the shift motor 335 is driven by an amount corresponding to, it stops.

  The cutter unit 4 is disposed on the lower side of the conveyance path of the recording paper P and the fixed blade 4a on the upper side of the conveyance path of the recording paper P, and is vertically moved with respect to the fixed blade 4a by a motor (not shown). The movable blade 4b moves to the lower side of the recording paper P, and the recording paper P is cut. Chips resulting from this cutting fall and are stored in a waste box (not shown) disposed in the lower part of the housing 3.

  The switchback unit 5 is provided so that the printing surface of the recording paper P faces upward when the recording paper P is discharged onto the conveying belt 151 of the conveyor device 150 by the decurling unit 8. Then, the recording paper P is switched back as described later.

  As shown in FIG. 2, FIG. 12 and FIG. 13, the switchback portion 5 includes a pressure-bonding type switchback roller pair 173 including a lower driving roller 173a and an upper driven roller 173b, and the switchback roller. A pair of first guide members 174 that are provided on the upstream side of the pair 173 so as to sandwich the transport path and guide the recording paper P transported from the transport roller pair 26 after cutting to the switchback roller pair 173, and the switched back recording A switch-backed recording paper P is provided so as to sandwich the conveyance path between the pressure-feed type supply roller pair 175 for supplying the paper P to the back surface printing unit 6, and the switchback roller pair 173 and the supply roller pair 175. A pair of second guide members 176 leading to the roller pair 175 is provided.

  The drive roller 173a of the switchback roller pair 173 is forwardly rotated by a motor (not shown) to sandwich the recording paper P and transport it to the front side of the printer, and reversely rotated to sandwich the recording paper P and transport it to the rear side of the printer. And is configured to be possible.

  The switchback roller pair 173 and the first guide member 174 can be integrally rotated around the rotation axis of the drive roller 173a of the switchback roller pair 173 by a motor (not shown). The relative position of the driven roller 173b with respect to the driving roller 173a of the back roller pair 173 is positioned almost directly above the driving roller 173a as shown in FIG. Position and a second position which is located on the rear side of the printer with respect to the driving roller 173a and supplies the switched back recording paper P from the rear end side to the back surface printing unit 6 (upward) as shown in FIG. And can be switched to.

  Here, a switchback operation for switching back the recording paper P conveyed from the conveyance roller pair 26 after cutting will be described. When the switchback roller pair 173 receives the recording paper P conveyed from the conveying roller pair 26 after cutting, the driving roller 173a is rotating forward and the driven roller 173b is in the first position. When the recording paper P is conveyed to the rear side of the printer by the switchback roller pair 173 by an amount such that the rear end of the recording paper P is positioned on the first guide member 174 (see FIG. 12), the drive roller 173a rotates forward. To stop.

  At this time, the leading end portion of the recording paper P is bent and bent downward due to the weight of the recording paper P. When the recording paper P is stiff and does not bend due to its own weight, the curved guide plate 177 provided on the downstream side in the conveyance direction of the recording paper P with respect to the switchback roller pair 173 (the rear side of the printer). When the tip end abuts, it is bent downward along the curved guide plate 177.

  Subsequently, the switchback roller pair 173 and the first guide member 174 are rotated in the clockwise direction in FIG. 12 around the rotation axis of the driving roller 173a to move the driven roller 173b from the first position to the second position. Switching (see FIG. 13). As a result, the rear end side (front side of the printer) of the recording paper P is lifted, and the front end side of the recording paper P is in a state where it hangs down due to its own weight. That is, the recording paper P is in a state extending in the vertical direction.

  Thereafter, the drive roller 173a is rotated in the reverse direction, and the recording paper P is conveyed from the rear end side toward the supply roller pair 175 side. The recording paper P to be switched back by the switchback roller pair 173 passes through the first guide member 174 and the second guide member 176 and reaches the supply roller pair 175.

  In this embodiment, the position of the switchback roller pair 173 is switched between the first position and the second position by rotating the driven roller 173b around the drive roller 173a of the switchback roller pair 173. However, the present invention is not limited to this configuration. For example, the drive roller 173a and the driven roller 173b are both movable, and the first position can be changed by changing the position of the entire switchback roller pair 173. The second position may be switched.

  In this embodiment, the switchback roller pair 173 includes the drive roller 173a that conveys the recording paper P and the driven roller 173b that rotates following the drive roller 173a. Both rollers may be configured as drive rollers.

  A recording paper collection box 83 that opens upward is provided below the switchback unit 5 (see FIG. 2). The recording paper collection box 83 is for collecting the recording paper P remaining in the conveyance path when an abnormality such as a paper jam occurs during the operation of the printer A. That is, when an abnormality occurs, the recording paper P remaining on the transport path is transported to the switchback unit 5 by the recording paper transport mechanism. The switchback unit 5 receives the recording paper P and discharges it to the collection box 83. Thus, when an abnormality occurs, it is not necessary to open various portions of the housing 3 in order to remove the recording paper P remaining in the conveyance path, and it is only necessary to open only a portion where the recording paper collection box 83 can be taken out.

  The back surface printing unit 6 is composed of a dot impact type thermal printer, and is disposed on the back surface side of the recording paper P (on the rear side of the printer with respect to the transport path). On the downstream side in the transport direction of the recording paper P with respect to the back surface printing unit 6, a transport roller pair 28 for feeding the recording paper P after back surface printing is disposed. Then, the recording paper P is conveyed to the drying unit 7 disposed on the downstream side in the conveyance direction of the recording paper P with respect to the conveyance roller pair 28 by the rotation of the conveyance roller pair 28.

  The drying unit 7 dries a plurality of suction fans 154 for taking air into the drying device 153, a plurality of heaters 155 for heating the air taken in by the suction fans 154, and the air heated by the heater 155. It has a plurality of exhaust nozzle parts 156 that blow on the printing surface of the recording paper P as wind. The drying air from the exhaust nozzle unit 156 is blown onto the printing surface of the recording paper P, so that the ink attached to the printing surface of the recording paper P is dried.

  The decurling unit 8 includes a driving conveyance roller 81 and a decurling roller 82 configured to be movable around the driving conveyance roller 81. The decurling unit 8 switches the position of the decurling roller 82 between the conveying position and the decurling position depending on whether the recording sheet P to be transported is a roll-shaped recording sheet P or a sheet-shaped recording sheet P. The conveying position is a position where the decurling roller 82 is positioned directly above the driving conveying roller 81. At this conveying position, the recording paper P is conveyed without being decurled by both the rollers 81 and 82. On the other hand, the decurling position is a position where the decurling roller 82 is rotated in the clockwise direction in FIG. 2 around the driving conveying roller 81 from the conveying position. At this decurling position, the recording paper P is conveyed while being decurled by both rollers 81 and 82.

  The decurling unit 8 controls the decurling roller 82 to the conveying position when the recording sheet P conveyed from the drying unit 7 is the sheet-shaped recording sheet P supplied from the manual feed tray 102. On the other hand, when the recording paper P is a roll-shaped recording paper P drawn from the magazines M1 and M2, the decurling roller 82 is controlled to the decurling position. Thus, the decurling process is not performed on the recording paper P supplied from the manual feed tray 102, and the decurling process is performed on the recording paper P drawn from the magazines M1 and M2, and is wound into a roll shape. Remove curl due to curl when moving.

  The accumulating device 210 is for accumulating the recording paper P conveyed from the conveyor device 150, and is disposed at the upper and lower ends of the accumulating main body 211, and a box-shaped accumulating main body 211 having an opening on the front side of the printer. An endless stacking belt 213 wound around a pair of rollers (not shown) with a predetermined tension, and a stacking plate 212 provided on the outer peripheral surface of the stacking belt 213 at substantially equal intervals. Yes. The roller pair is connected to a drive motor (not shown) for rotating the accumulation belt 213 to move the accumulation plate 212 in the transport direction.

  Of the plurality of stacking plates 212, the stacking plate 212 exposed to the outside of the stacking main body 211 moves downward along with the rotation of the stacking belt 213, and is accommodated in the stacking main body 211. The accumulation plate 212 is configured to move upward in accordance with the rotation operation of the accumulation belt 213. The stacking plate 212 waits so that the plate surface is horizontal and substantially flush with the belt surface of the transport belt 151 at the transfer position of the recording paper P positioned on the right side of the printer with respect to the transport belt 151. Then, the recording paper P conveyed to the right side of the printer by the conveying belt 151 is received from the conveying belt 151. After the number of sheets corresponding to a predetermined print order is accumulated on the accumulation plate 212, the accumulation plate 212 is conveyed downward by the accumulation belt 213 before the next order of recording paper P is conveyed.

  As shown in FIG. 14, the inkjet printer has a microprocessor 201 (hereinafter referred to as a CPU), a conveyance control unit 202 connected to the CPU 201 via a data bus, a head control unit 203, and print control. , A semiconductor memory 205 including a ROM and a RAM, a communication interface 206, a cutting control unit 207, a capping control unit 208, and a cleaning control unit 209. These are configured in the control unit. Further, input terminals of the control unit include the upper position sensor 301, the lower position sensor 302, a standby position detection sensor 303 (also described in FIG. 7) for detecting that the print head H has reached the standby position, and An operation unit 300 for the operator to input the type of the recording paper P is connected.

  The conveyance control unit 202 controls the operation of the recording paper conveyance mechanism. The head controller 203 drives the drive motor 11 for reciprocating the print head H in the main scanning direction, and controls ink ejection by supplying a voltage having a predetermined waveform to each piezoelectric element. The communication interface 206 is for transmitting and receiving information to and from the reception block 200. Each of the transport control unit 202 and the head control unit 203 receives a command from the print control unit 204 and outputs a necessary control signal. The print control unit 204 performs control for realizing printing of image data on the recording paper P based on the image data received from the reception block 200 via the communication interface 206. The cutting control unit 207 performs operation control of a motor that operates the movable blade 4 b of the cutter unit 4.

  The capping control unit 208 performs a capping control operation for bringing each cap member 350 into close contact with the ink ejection surface 13a of each head unit 13 of the print head H. This capping control operation will be described based on the flowchart of FIG.

  That is, in step S101, the drive motor 11 is driven to move the print head H. When the standby position detection sensor 303 detects that the print head H has reached the standby position, the drive motor 11 is stopped. The print head H is set at the standby position.

  In the next step S102, the cap member 350 is moved to the contact position. That is, the shift motor 335 is rotated forward to move the shift member 332 upward, and the shift motor 335 is driven by an amount corresponding to a preset number of pulse signals from the timing when the upper position sensor 301 outputs a detection signal. Stop after.

  The cleaning control unit 209 performs a cleaning control operation for cleaning each head unit 13 of the print head H when a cleaning execution condition described later is satisfied.

  The cleaning control operation by the cleaning control unit 209 will be described based on the flowchart of FIG. This cleaning control operation is performed after the cap member 350 is moved to the contact position by the capping controller 208 as described above.

  In the first step S201, with the electromagnetic valve 357 closed, the pump motor 356 is driven and the suction pump 355 depressurizes the inside of the recess 350a of the cap member 350. Ink is ejected from the ink. This operation is performed for a preset first set time. By this operation, ink whose viscosity is increasing in the nozzle hole is forcibly discharged, and paper dust entering the nozzle hole is discharged together with the ink to the outside of the nozzle hole. Thereby, the clogging of the nozzle hole is recovered. The ink discharged from the nozzle holes is sucked by the suction pump 355 via the decompression tube 353 and collected by the collecting unit 358.

  Subsequently, in step S202, the discharge of ink from the nozzle holes is stopped while the pressure reduction by the suction pump 355 is continued, and the cap valve 350 is opened via the air supply tube 354 by opening the electromagnetic valve 357. The air is supplied into the recess 350a. This operation is performed for a preset second set time. This operation promotes the discharge of ink in the recess 350a.

  Next, in step S203, while the pressure reduction by the suction pump 355 is continued, the shift motor 335 is reversely rotated to lower the shift member 332, whereby each cap member 350 is ejected from each head unit 13 of the print head H. In step S204, the cap member 350 is separated from the ink ejection surface 13a, and the decompression by the suction pump 355 is stopped.

  Next, in step S205, the wiping member 346 is set at the wiping position. As shown in FIG. 17A, the wiping position is a height position at which the tip of each wiping member 346 can abut against the ink ejection surface 13a of each head unit 13 of the print head H. The height position of the shift member 332 is below the height position of the shift member 332 when the cap member 350 is located at the close contact position. In order to set the wiping member 346 at the wiping position, the shift member 332 continues to descend from step S203, and the wiping member 346 is positioned below the wiping position (the upper position sensor 301 detects the light shielding piece 340). And move it so that it is located on the lower side. Thereafter, the shift motor 335 is rotated forward to raise the shift member 332. Then, from the timing when the upper position sensor 301 outputs the detection signal, the shift motor 335 corresponds to a preset number of pulse signals (less than the number of pulse signals when the cap member 350 is moved to the contact position). The wiping member 346 is set at the wiping position by stopping after driving.

  Next, in step S206, a cleaning operation of the ink discharge surface 13a of each head unit 13 is performed. That is, by driving the drive motor 11, the print head H is operated to the side away from the standby position in the main scanning direction X (the platen 45 side), and the tip of each wiping member 346 is moved to the head unit 13 of the print head H. Cleaning is performed in such a manner that the ink discharge surface 13a is brought into sliding contact with each other. In the cleaning operation of the ink discharge surface 13a, as shown in FIG. 17B, the print head H moves by a predetermined amount so that the tip of the wiping member 346 passes through the nozzle hole formation region F on the ink discharge surface 13a. At that time, the drive motor 11 is stopped, and then, as shown in FIG. 18, the shift motor 335 is rotated in the reverse direction to lower the shift member 332, thereby causing each wiping member 346 to eject ink from each head unit 13. Separated from the surface 13a. Thereafter, the print head H is moved to the standby position by driving the drive motor 11.

  In the next step S207, it is determined whether or not the cleaning operation of the ink discharge surface 13a has been performed a predetermined number of times. If the determination in step S207 is NO, the process returns to step S205, and the operations in steps S205 to S207 are repeated. On the other hand, if the determination in step S207 is YES, the process returns.

  As described above, the cleaning operation of the ink discharge surface 13a is performed for the set number of times, and the paper dust generated from the recording paper P and attached to the ink discharge surface 13a is surely removed.

  The semiconductor memory 205 (ROM) stores preset cleaning execution conditions for each type of recording medium (in this embodiment, recording paper P) used in the printer A. In the present embodiment, the semiconductor memory 205 is not only used for storing cleaning conditions but also used for other storage. However, a dedicated semiconductor memory may be provided for storing cleaning conditions. Further, not only the semiconductor memory 205 but also a cleaning execution condition may be stored in, for example, a hard disk device.

  In the present embodiment, the cleaning execution condition for each type of recording medium (recording paper P) is the print head from the end of the previous cleaning (after the end of the previous cleaning control operation) for each type of recording paper P. The accumulated value of the peripheral length of the recording paper P printed by H is preset.

  Specifically, the cleaning condition for each type of recording paper P is the cumulative value of the circumference of the recording paper P printed by the print head H after the end of the previous cleaning, for each type of recording paper P. Is a condition that a value obtained by multiplying a preset first coefficient exceeds a first predetermined value.

  In this embodiment, the types of recording paper P used in the printer A are coated paper (glossy photographic paper), non-coated paper (semi-glossy photographic paper), and plain paper, and each first coefficient is k1. , K2 and k3. Among these, plain paper is most likely to generate paper dust, and the paper dust is likely to adhere to the nozzle holes on the ink discharge surface 13a of each head unit 13 of the print head H and the periphery thereof. For this reason, the first coefficient k3 of plain paper is set to the largest value. Coated paper is the least likely to generate paper dust. For this reason, the first coefficient k1 of the coated paper is set to the smallest value. That is, the first coefficient has a relationship of k1 <k2 <k3. When the postcard is made usable, the first coefficient of the postcard becomes the largest.

  The operator operates the operation unit 300 to determine whether the recording paper P to be printed by the printer A is the roll-shaped recording paper P in the magazine M1 or the magazine M2, or is set on the manual feed tray 102. Whether the sheet P is a sheet-like recording paper P is selected and input, and the type of the selected recording paper P is selected and input.

  The selection input information of the recording paper P is sent to the printing control unit 204, and is also sent from the printing control unit 204 to the conveyance control unit 202 and the head control unit 203, and the selected recording paper P is sent to the printing unit 2. And is printed on the recording paper P by the print head H. Further, the selection input information of the type of the recording paper P is sent to the cleaning control unit 209.

  Then, the cleaning control unit 209 performs the cleaning control operation when the cleaning execution condition corresponding to the type of the input recording paper P stored in the semiconductor memory 205 is satisfied, A clogging recovery operation (forcibly discharging ink from the nozzle holes) is performed, and the ink ejection surface 13a is cleaned. In other words, the accumulated value of the circumference of the recording sheet P printed by the print head H after the end of the previous cleaning (after the end of the previous cleaning control operation) indicates the type of the input recording sheet P. When the value multiplied by the first coefficient exceeds the first predetermined value, the cleaning control operation is newly performed.

  Here, in the case of the sheet-like recording paper P, the cumulative value of the peripheral length of the recording paper P is added to the total length of the four sides of the recording paper P every time printing of the recording paper P is completed. It is the value. On the other hand, in the case of the roll-shaped recording paper P, since the cutting by the cutter unit 4 has not yet been performed at the time of printing, the accumulated value of the peripheral length of the recording paper P is 2 adjacent to each other in the roll-shaped recording paper P. It is a value obtained by adding the total length of two sides facing the width direction (main scanning direction X) of the recording paper P between the two scheduled cutting portions for each printing end between the two scheduled cutting portions.

  Since the paper dust is generated from the edge of the recording paper P, the increase in the cumulative value is considered to be that much paper dust is generated and attached to the ink ejection surface 13a or enters the nozzle hole. . The cleaning control operation needs to be performed when a large amount of paper dust that has an influence on ink ejection adheres to the ink ejection surface 13a or enters the nozzle hole. Here, in the case of plain paper, it is considered that more paper dust adheres to the ink ejection surface 13a or enters into the nozzle holes even if the cumulative value is the same as that of the coated paper. Therefore, a first coefficient that differs for each type of recording paper P is multiplied by the accumulated value, and the cleaning control operation is performed when the accumulated value becomes larger than a first predetermined value. By doing so, the cleaning interval is shortened when printing on plain paper that is likely to generate paper dust, and the cleaning interval is increased when printing on coated paper that is less likely to generate paper dust. . As a result, an appropriate cleaning condition can be set for each type of recording paper P to be printed, so that nozzle holes are not clogged with paper dust, and wasteful ink can be prevented from being discharged during cleaning.

  In this embodiment, the drive motor 11 (print head drive mechanism), the cleaning control unit 209, the shift motor 335 (shift member drive mechanism V), the wiping member 346, the suction pump 355 (including the pump motor 356), and each head The piezoelectric element of the unit 13 constitutes a cleaning means for cleaning the print head, and the semiconductor memory 205 (ROM) constitutes a storage means for storing a cleaning execution condition set in advance for each type of recording medium, The operation unit 300 constitutes a type obtaining unit that obtains the type of the recording medium printed by the print head H.

  The present invention is not limited to the above-described embodiment, and can be substituted without departing from the scope of the claims.

  For example, in the above-described embodiment, the cleaning execution condition for each type of recording paper P is set to the accumulated value of the peripheral length of the recording paper P printed by the print head H after the end of the previous cleaning. The condition that the value obtained by multiplying the first coefficient set in advance for each type exceeds the first predetermined value is the cumulative value of the thickness of the recording paper P printed by the print head H since the end of the previous cleaning. In addition, the value obtained by multiplying the second coefficient set in advance for each type of the recording paper P may exceed the second predetermined value, or both of these conditions may be used. The relationship of the magnitude of the second coefficient for each type of recording paper P is the same as that of the first coefficient, and increases in the order of coated paper, non-coated paper, and plain paper. In the case of a sheet-like recording paper P, the cumulative value of the thickness of the recording paper P is a value obtained by adding the thickness of the recording paper P every time printing of one recording paper P is completed. In the case of the paper P, it is a value obtained by adding the thicknesses of the recording paper P every time printing is completed between two adjacent scheduled cutting portions in the roll-shaped recording paper P.

  Alternatively, the cleaning condition for each type of recording paper P is obtained by multiplying the cumulative value of the scanning time of the print head H after the end of the previous cleaning by a third coefficient preset for each type of recording paper P. It is good also as conditions that a value exceeds predetermined time. The relationship of the magnitude of the third coefficient for each type of recording paper P is the same as the first coefficient and the second coefficient, and increases in the order of coated paper, non-coated paper, and plain paper. The accumulated value of the scanning time of the print head H is a value obtained by adding the time required for the scanning for each end of scanning of the print head H. As this cumulative value increases, a larger amount of paper dust may adhere to the ink ejection surface 13a. However, since the amount of paper dust varies depending on the type of recording paper P, the amount of paper dust varies depending on the type of recording paper P. By adjusting the cumulative value by the third coefficient, it becomes possible to perform the cleaning control operation at an appropriate timing for each type of the recording paper P.

  Further, the recording medium used in the printer A is not limited to the recording paper P, and may include a resin sheet, for example. When the printer A can use a resin sheet in addition to the recording paper P of the above-described embodiment, the cleaning execution condition for the resin sheet may be stored in the semiconductor memory 205. In the case of this resin sheet, resin powder is generated, and the values of the first coefficient, the second coefficient, and the third coefficient may be set according to the ease of generation of the resin powder.

  Furthermore, the cleaning execution condition may be any condition as long as the cleaning execution interval is appropriate according to the ease of generation of recording medium powder such as paper powder and resin powder.

  In the above-described embodiment, the cleaning is performed in such a manner that the wiping member 346 is slidably contacted with the ink discharge surface 13a. However, the cleaning is not limited thereto, and the cleaning may be performed, for example, by blowing air.

  Further, in the above-described embodiment, the type of the recording paper P printed by the print head H is obtained by the operation unit 300, but the present invention is not limited to this. For example, the magazines M1 and M2 are provided with an identification code portion for identifying the type information of the recording paper P stored therein, and the recording paper storage portion 1 is provided with a sensor for reading the information of the identification code portion. You may make it acquire the kind of recording paper P printed by the print head H with this sensor. Alternatively, the print head H or the like is provided with a sensor for projecting light onto the printing surface of the recording paper P and detecting the amount of reflected light of the light, and the recording paper P printed by the print head H by this sensor. You may make it acquire the kind of.

  Furthermore, the following items may be taken into consideration when setting the cleaning execution conditions. That is, when the usage ratio of a specific color ink (especially black) out of the seven colors of ink is higher than a predetermined value (may be determined from image data or may be determined from an actual ink ejection operation). In addition, since paper dust tends to accumulate in the nozzle holes that eject inks of colors other than the specific color ink, the cleaning interval is shortened, and when the use ratio of the specific color ink is below a predetermined value, Make the cleaning interval longer. In addition, the cleaning interval is shortened as the length of the recording sheet P conveyed by the conveyance roller pair 25 after printing increases. This is because the longer the recording paper P is, the longer the length of the recording paper P is when the recording paper P is rubbed against the platen 45 due to being rubbed against the left and right guide members 41, 42 of the guide portion 23. This is because no paper dust will be generated. Further, when the two head units 13 are configured to be movable in the main scanning direction X independently of each other and the cleaning control operation can be performed independently of each other, the two head units 13 are closer to the cutter unit 4. In the head unit 13 on the downstream side in the conveyance direction of the recording paper P, paper dust generated by cutting by the cutter unit 4 is likely to adhere, so that the cleaning interval is shorter than the head unit 13 on the far side of the cutter unit 4. Like that.

  The above-described embodiments are merely examples, and the scope of the present invention should not be construed in a limited manner. The scope of the present invention is defined by the scope of the claims, and all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  INDUSTRIAL APPLICABILITY The present invention is useful for an ink jet recording apparatus that includes a print head that performs printing by ejecting ink onto a recording medium and a cleaning unit that cleans the print head.

A Printer (inkjet recording device)
H Print head P Recording paper (recording medium)
11 Drive motor (cleaning means)
205 Semiconductor memory (storage means)
209 Cleaning control unit (cleaning means)
300 Operation unit (type acquisition means)
335 Shift motor (cleaning means)
346 Wiping member (cleaning means)
355 Suction pump (cleaning means)
356 Pump motor (cleaning means)

Claims (4)

An ink jet recording apparatus comprising: a print head that performs printing by discharging ink to a recording medium; and a cleaning unit that cleans the print head,
Storage means for storing cleaning execution conditions set in advance for each type of the recording medium;
A type obtaining means for obtaining a type of a recording medium printed by the print head;
The cleaning unit is configured to clean the print head when a cleaning execution condition corresponding to the type of the recording medium obtained by the type obtaining unit stored in the storage unit is satisfied. An ink jet recording apparatus. The inkjet recording apparatus according to claim 1, wherein
The cleaning execution condition for each type of the recording medium includes, for each type of the recording medium, the cumulative value of the peripheral length of the recording medium printed by the print head and the thickness of the recording medium after the end of the previous cleaning. An ink jet recording apparatus that is preset with respect to at least one of the cumulative values. The inkjet recording apparatus according to claim 2.
The cleaning execution condition for each type of the recording medium is set to a cumulative value of the peripheral length of the recording medium printed by the print head since the end of the previous cleaning. For each type of recording medium, the condition that the value multiplied by one coefficient exceeds the first predetermined value and the cumulative value of the thickness of the recording medium printed by the print head after the end of the previous cleaning are stored in advance. An ink jet recording apparatus characterized in that at least one of the conditions in which a value obtained by multiplying a set second coefficient exceeds a second predetermined value. The inkjet recording apparatus according to claim 1, wherein
The cleaning condition for each type of the recording medium is a predetermined time obtained by multiplying the cumulative value of the scanning time of the print head after the end of the previous cleaning by a coefficient set in advance for each type of the recording medium. An ink jet recording apparatus characterized in that the condition is exceeded.

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