JP2016168805A - Sheet dryer and inkjet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet dryer capable of performing dry processing by stably conveying a sheet and an inkjet printer.SOLUTION: A sheet dryer performs dry processing on a sheet P by blowing hot air from a nozzle 142 to the sheet P conveyed along a guide surface 122A with the tip being held. ON/OFF of the blowing of the hot air from the nozzle 142 is controlled in accordance with the position of the sheet P. When the position on the guide surface 122A to which the hot air from the nozzle 142 is blown is the blowing position, blowing of the hot air is turned into the ON state immediately before the tip of the sheet P reaches the blowing position, and the blowing of the hot air is turned into the OFF state immediately before the rear end of the sheet P reaches the blowing position. Consequently, the wind blown from the nozzle 142 can be prevented from entering below the sheet P and flipping of the sheet P can be prevented.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a paper drying apparatus and an ink jet printer for drying a sheet of paper.

  In an ink jet printer, there is a case where a paper is dried immediately after printing in order to promote drying of ink deposited on the paper.

  Patent Document 1 discloses a method of drying a sheet immediately after printing by transporting the sheet immediately after printing by chain delivery and blowing hot air on the surface of the sheet during the transport process. Proposed. Japanese Patent Application Laid-Open No. 2004-228561 proposes that when transporting paper by chain delivery, the paper is transported along the suction plate and transported while sucking the back surface of the paper with the suction plate.

Japanese Patent Application Laid-Open No. 2014-117846

  By the way, in the chain delivery, the paper is conveyed by holding only the leading edge of the paper. For this reason, there is a problem that when warm air is blown onto the paper conveyed by the chain delivery, the paper flutters under the influence of the wind.

  In Japanese Patent Laid-Open No. 2004-260688, since the rear surface of the paper is conveyed while being sucked, there is no problem of fluttering. However, when a double-sided printed paper is dried by the same method, the printed image is rubbed and scratched. is there.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a paper drying apparatus and an ink jet printer that can stably carry and dry paper.

  (1) In a sheet drying apparatus for drying a sheet of sheet, the sheet drying apparatus includes a guide unit having a guide surface for guiding sheet conveyance, and a plurality of grippers that travel at regular intervals along a predetermined traveling path. Conveying means that grips the leading edge of the paper and continuously conveys multiple papers along the guide surface, and a nozzle that blows the wind for drying. Conveys air by blowing air from the nozzle toward the guide surface. A blower that blows air on the paper conveyed by the means; a paper position detection means that detects the position of the paper conveyed by the conveyance means; and the drive of the blower according to the position of the paper conveyed by the conveyance means. And a blowing control means for controlling the blowing of the wind from the nozzle, and the position on the guide surface where the wind blown from the nozzle is blown is defined as the blowing position Balloon control means stops at least between the rear end blew against the position of the paper after passing through the until it reaches the blow against position the leading edge of the next sheet, the balloon from the nozzle of the wind, the paper drying apparatus.

  According to this aspect, the sheet is conveyed along the guide surface while the leading end is gripped by the gripper. And in the conveyance process, the wind for drying is sprayed from a nozzle and it dries. The blowout of the wind from the nozzle is controlled by the blowout control means. The blowing control means stops blowing the wind from the nozzle at least after the trailing edge of the sheet passes the blowing position until the leading edge of the next sheet reaches the blowing position. That is, the blowing of wind between the sheets is temporarily stopped. Paper fluttering occurs when wind enters between the paper and the guide surface. By stopping the blowing of wind from the nozzles once before the next paper reaches the blowing position, it is possible to prevent the wind from entering under the next paper and to effectively suppress the fluttering.

  (2) The sheet drying device according to (1), wherein the blowing control unit stops blowing the wind from the nozzle until immediately before the leading edge of the next sheet reaches the blowing position.

  According to this aspect, the blowing of the wind from the nozzle is stopped until just before the leading edge of the next sheet reaches the blowing position. The blowing of wind from the nozzle can also be started after the leading edge of the paper has passed the blowing position, but in that case, the drying efficiency decreases. On the other hand, if the blowing of wind starts a long time before the leading edge of the paper reaches the blowing position, the blown wind enters under the paper and induces flapping. Therefore, by starting the blowing of wind just before the leading edge of the sheet reaches the blowing position, the wind blows on the entire sheet while preventing flapping.

  Here, to what extent immediately before the blowing of the wind is stopped is determined in consideration of the flapping of the paper caused by starting the blowing of the wind. That is, the position where the wind blowing is started is determined so that the fluttering is within the allowable range.

  Note that the flapping of the paper varies depending on the paper size, the paper thickness, the speed at which the paper is conveyed, the amount of air blown from the nozzle, and the like. Therefore, the position where the balloon is started is determined in consideration of these.

  In addition, the allowable range of flapping is determined in consideration of paper contact and the like. That is, the sheet is set in a range where the surface of the sheet does not come into contact with other structures due to the sheet floating.

  (3) The paper drying device according to (1) or (2), wherein the blowout control unit stops the blowing of wind from the nozzle immediately before the trailing edge of the paper passes through the blowing position.

  According to this aspect, the blowing of wind from the nozzle is stopped immediately before the trailing edge of the sheet passes the blowing position. When the paper transported in front passes through the spray position, there is no force to press the paper from above. As a result, wind enters under the sheet from the rear end side of the sheet, and the previous sheet is lifted. By stopping the blowing of wind from the nozzle just before the trailing edge of the paper passes the blowing position, it is possible to prevent the wind from entering under the paper from the trailing edge of the paper, and the effect of flapping the paper Can be prevented.

  (4) Any one of the above (1) to (3), wherein a plurality of nozzles are arranged at regular intervals along the paper conveyance path, and the blowing control unit individually controls the blowing of wind from the nozzles. Paper drying equipment.

  According to this aspect, a plurality of nozzles are arranged at a specified interval along the paper conveyance path, and the blowing is controlled individually. When the nozzle installation interval is wide, the paper fluttering can be effectively prevented by controlling the blowing of the wind individually as described above.

  (5) A position in which a plurality of nozzles are arranged at regular intervals along the paper conveyance path, the nozzle located at the uppermost stream in the paper conveyance direction is the top nozzle, and the wind blown from the top nozzle is blown Is the leading blowing position, the blowing control means blows wind from the nozzle until at least the trailing edge of the paper passes the leading blowing position and the leading edge of the next sheet reaches the leading blowing position. The paper drying apparatus according to any one of (1) to (3), wherein the paper drying is stopped collectively.

  According to this aspect, a plurality of nozzles are arranged at regular intervals along the paper conveyance path, and the blowing of wind is controlled collectively. At this time, the blowing of wind is controlled based on the leading nozzle located at the uppermost stream. That is, the blowing of the wind is stopped at least after the trailing edge of the sheet passes the leading blowing position until the leading edge of the next sheet reaches the leading blowing position. When the interval between the nozzles is narrow, even if the blowing of the wind is controlled in this way, paper flapping can be effectively prevented.

  (6) If the nozzle located on the most downstream side with respect to the paper transport direction is the rearmost nozzle, and the position where the air blown from the rearmost nozzle is blown is the last blown position, the blowing control means includes at least the paper The paper of the above (5), in which the blowing of wind from the nozzles is stopped at a time from immediately before the rear end of the paper passes through the last blowing position until the rear edge of the paper has passed through the last blowing position. Drying equipment.

  According to this aspect, in the case where the blowout of wind is controlled collectively, the blowout of wind is further controlled on the downstream side. That is, at least from the time immediately before the trailing edge of the sheet passes the last blowing position until the trailing edge of the sheet has passed the last blowing position, the blowing of wind from the nozzles is stopped collectively. Thereby, it is possible to prevent the wind from entering under the sheet from the rear end side of the sheet, and to effectively prevent the sheet from flapping.

  (7) The blower unit includes an air source that supplies air to the nozzle and a valve that opens and closes a flow path of air sent from the air source to the nozzle, and controls the blowing of air from the nozzle by opening and closing the valve. The paper drying device according to any one of (1) to (6) above.

  According to this aspect, the blowing of wind from the nozzle is controlled by opening and closing the valve. Thereby, ON / OFF of the blowing of a wind can be switched easily.

  (8) The blowing unit includes a fan that blows air toward the nozzle and a shutter that opens and closes the nozzle, and controls the blowing of air from the nozzle by opening and closing the shutter. Any one paper drying device.

  According to this aspect, the blowing of wind from the nozzle is controlled by opening and closing the shutter. Thereby, ON / OFF of the blowing of a wind can be switched easily.

  (9) The paper drying apparatus according to any one of (1) to (8), wherein the nozzle blows air perpendicularly to the guide surface, and the spray position is set to a nozzle installation position.

  According to this aspect, the wind is blown out perpendicularly to the guide surface from the nozzle.

  (10) The paper drying apparatus according to any one of (1) to (9), wherein the transport unit is configured by chain delivery.

  According to this aspect, the conveying means is configured by chain delivery.

  (11) An ink jet comprising: a printing unit that prints on a sheet of paper by an inkjet method; and the paper drying device according to any one of (1) to (10) that performs a drying process on the paper printed by the printing unit. Printer.

  According to this aspect, the paper immediately after printing can be dried in the inkjet printer.

  According to the present invention, paper can be stably conveyed and dried.

Front view showing overall schematic configuration of inkjet printer 1 is a plan view of the ink jet printer shown in FIG. The perspective view which shows the structure of the principal part of an ink drying part. Front view showing schematic configuration of hot air blowing unit Sectional drawing which shows schematic structure of an air blower Block diagram showing schematic configuration of control system of inkjet printer Block diagram of a computer that functions as a balloon control unit Conceptual diagram of hot air blowing control State transition diagram when controlling the blowing of hot air from the nozzles individually State transition diagram when controlling the blowing of hot air from the nozzles individually ON / OFF timing chart of the blowout of each nozzle in the case of individually controlling the blowout of hot air from the nozzle Conceptual diagram for controlling the blowing of hot air from the nozzles collectively State transition diagram for controlling hot air blowing from the nozzles collectively State transition diagram for controlling hot air blowing from the nozzles collectively State transition diagram for controlling hot air blowing from the nozzles collectively ON / OFF timing chart of the blowout of each nozzle when controlling the blowout of hot air from the nozzles collectively The perspective view which shows the other form of a nozzle Sectional drawing which shows another example of a warm air ventilation unit Sectional drawing which shows another example of a warm air ventilation unit

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

<Inkjet printer>
FIG. 1 is a front view showing an overall schematic configuration of an inkjet printer to which the present invention is applied. FIG. 2 is a plan view of the ink jet printer shown in FIG.

  The ink jet printer 1 is a sheet-fed color ink jet printer that prints a color image on a sheet of paper P, and is particularly an aqueous ink jet printer that uses water-based ink to print on a general-purpose printing paper. Here, the general-purpose printing paper is not so-called ink jet dedicated paper but means paper mainly composed of cellulose such as coated paper used in offset printing or the like. Further, the water-based ink refers to an ink in which a coloring material such as a dye or a pigment is dissolved or dispersed in water and a water-soluble solvent.

  As shown in FIGS. 1 and 2, the inkjet printer 1 mainly includes a paper feeding unit 10 that feeds paper P and a processing liquid application that applies a pretreatment liquid to the paper P fed from the paper feeding unit 10. Unit 20, a processing liquid drying unit 30 for drying the paper P coated with the pretreatment liquid, a printing unit 40 for printing a color image on the dried paper P by an ink jet method, and the printed paper P An ink drying unit 100 that performs drying processing, a stacking unit 60 that stacks the dried paper P, and a maintenance unit 70 that performs maintenance of the inkjet head are configured.

<Paper Feeder>
The paper feeding unit 10 automatically feeds the paper P one by one. As shown in FIGS. 1 and 2, the paper feeding unit 10 mainly includes a paper feeding device 12, a feeder board 14, and a paper feeding drum 16.

  The sheet feeding device 12 takes out the sheets P set on the sheet feeding tray 12 </ b> A in a bundled state one by one from the top and feeds them to the feeder board 14.

  The feeder board 14 receives the paper P fed from the paper feeding device 12 and transfers the received paper P to the paper feeding drum 16.

  The paper supply drum 16 receives the paper P fed from the feeder board 14 and transfers the received paper P to the processing liquid application unit 20.

<Processing liquid application part>
The treatment liquid application unit 20 applies a pretreatment liquid to the paper P. This pretreatment liquid is a liquid having a function of aggregating, insolubilizing or thickening the color material component in the ink. By applying such a pretreatment liquid to the paper P, a high-quality image can be printed even when printing is performed on a general-purpose printing paper using water-based ink.

  As shown in FIGS. 1 and 2, the treatment liquid application unit 20 mainly applies a treatment liquid application drum 22 that conveys the paper P and a process that applies the pretreatment liquid to the paper P that is conveyed by the treatment liquid application drum 22. And a liquid application device 24.

  The processing liquid application drum 22 receives the paper P from the paper supply drum 16 of the paper supply unit 10 and transfers the received paper P to the processing liquid drying unit 30. The treatment liquid coating drum 22 includes a gripper 23 on the peripheral surface, and the gripper 23 grips and rotates the front end of the paper P, whereby the paper P is wound around the peripheral surface and conveyed. Note that the leading edge of the paper P refers to the front end of the paper P in the transport direction.

  The treatment liquid application device 24 applies the pretreatment liquid to the paper P conveyed by the treatment liquid application drum 22. The pretreatment liquid is applied with a roller.

  The treatment liquid application unit 20 is configured as described above. The pretreatment liquid is applied to the print surface of the paper P in the process of being conveyed by the treatment liquid application drum 22. The print surface is a surface on which an image is printed.

<Processing liquid drying section>
The treatment liquid drying unit 30 performs a drying process on the paper P coated with the pretreatment liquid. The treatment liquid drying unit 30 mainly includes a treatment liquid drying drum 32 that conveys the paper P, and a hot air blower 34 that blows warm air on the print surface of the paper P conveyed by the treatment liquid drying drum 32. Composed.

  The processing liquid drying drum 32 receives the paper P from the processing liquid coating drum 22 of the processing liquid coating unit 20 and transfers the received paper P to the printing unit 40. The treatment liquid drying drum 32 is constituted by a frame assembled in a cylindrical shape, and includes a gripper 33 on the peripheral surface. The treatment liquid drying drum 32 conveys the paper P by gripping and rotating the front end of the paper P with the gripper 33.

  The hot air blower 34 is installed inside the processing liquid drying drum 32. The hot air blower 34 blows hot air on the paper P conveyed by the treatment liquid drying drum 32 to dry the pretreatment liquid.

  The treatment liquid drying unit 30 is configured as described above. In the course of being conveyed by the treatment liquid drying drum 32, the paper P is dried by blowing warm air onto the print surface on which the pretreatment liquid has been applied.

<Print section>
The print unit 40 prints a color image on the paper P using four colors of ink of cyan (C), magenta (M), yellow (Y), and black (K). As shown in FIG. 1, the print unit 40 mainly includes a print drum 42 that conveys the paper P, a head unit 44, and a scanner 48 that reads an image printed on the paper P.

  The print drum 42 receives the paper P from the processing liquid drying drum 32 of the processing liquid drying unit 30 and transfers the received paper P to the ink drying unit 100. The print drum 42 is provided with a gripper 43 on its peripheral surface, and the gripper 43 grips and rotates the leading end of the paper P, so that the paper P is wound around the peripheral surface and conveyed. Further, the print drum 42 includes a suction mechanism (not shown), and transports the paper P wound around the circumferential surface while sucking the circumferential surface. A negative pressure is used for the adsorption. The print drum 42 has a large number of suction holes on the peripheral surface, and sucks the paper P onto the peripheral surface by suction from the inside through the suction holes.

  The head unit 44 includes an inkjet head 46C that ejects cyan ink droplets, an inkjet head 46M that ejects magenta ink droplets, an inkjet head 46Y that ejects yellow ink droplets, and an inkjet head that ejects black ink droplets. 46K. The inkjet heads 46C, 46M, 46Y, and 46K are arranged at regular intervals on the transport path of the paper P by the print drum 42. Each inkjet head 46C, 46M, 46Y, 46K is mounted on a carriage (not shown) to form one head unit 44. The carriage is movably provided between the printing unit 40 and the maintenance unit 70.

  Each of the inkjet heads 46C, 46M, 46Y, and 46K is a line head that can print a desired image on the paper P conveyed by the print drum 42 in a single pass. Each of the inkjet heads 46C, 46M, 46Y, and 46K has a nozzle surface at the tip, and ejects ink droplets from the nozzles provided on the nozzle surface toward the paper P conveyed by the print drum 42.

  The scanner 48 reads an image printed on the paper P by the ink jet heads 46C, 46M, 46Y, and 46K.

  The print unit 40 is configured as described above. In the process of being conveyed by the print drum 42, the paper P is ejected onto the print surface by ink droplets of cyan, magenta, yellow, and black from each of the inkjet heads 46C, 46M, 46Y, and 46K constituting the head unit 44. A color image is printed on the print surface. The image printed on the paper P is read by the scanner 48 as necessary.

<Ink drying section>
The ink drying unit 100 performs a drying process on the paper P printed by the printing unit 40. The ink drying unit 100 is an example of a paper drying device when incorporated in an inkjet printer.

  As shown in FIGS. 1 and 2, the ink drying unit 100 mainly applies a chain delivery 110 for conveying the paper P, a paper guide 120 for guiding the conveyance of the paper P, and the paper P conveyed by the chain delivery 110. A hot air blowing unit 130 that blows hot air and a paper detection sensor 150 that detects the paper P are configured.

[Chain Delivery]
The chain delivery 110 is an example of a transport unit. The chain delivery 110 receives the paper P from the print drum 42 of the printing unit 40 and transfers the received paper P to the stacking unit 60. The chain delivery 110 includes a pair of endless chains 112 that travel along a prescribed travel route, and grips the leading edge of the paper P with a gripper 114 provided on the pair of chains 112, thereby allowing the paper P to pass through a prescribed transport route. Convey along. A plurality of grippers 114 are provided in the chain 112 at regular intervals.

  FIG. 3 is a perspective view illustrating a configuration of a main part of the ink drying unit.

  As shown in FIG. 3, the gripper 114 is attached between a pair of chains 112. The gripper 114 includes a bar-shaped gripper main body 114A, and grips the leading edge of the paper P by a plurality of gripping claws 114B provided in the gripper main body 114A. The gripping claws 114B are opened and closed in conjunction with the receipt and delivery of the paper P.

  The chain delivery 110 includes a horizontal first transport section, an inclined upward second transport section, and a horizontal third transport section as transport sections of the paper P. The paper P delivered from the print drum 42 to the chain delivery 110 is first transported through the horizontal first transport section. Thereafter, the second transport section is transported upward, transported again through the third transport section in the horizontal direction, and delivered to the stacking unit 60.

[Paper Guide]
The paper guide 120 guides the conveyance of the paper P. The paper guide 120 is an example of a guide unit. As shown in FIG. 1, the sheet guide 120 includes a first sheet guide 122 and a second sheet guide 124.

  The first sheet guide 122 guides the conveyance of the sheet P conveyed in the first conveyance section. The first paper guide 122 includes a flat guide surface 122A. The guide surface 122A of the first paper guide 122 is provided in parallel with the chain 112 traveling in the first conveyance section. Accordingly, the guide surface 122A of the first paper guide 122 is provided horizontally. The paper P transported in the first transport section is transported along the guide surface 122A of the first paper guide 122, and is transported while sliding on the guide surface 122A of the first paper guide 122. That is, since the paper P is transported with only the leading edge held, the trailing edge hangs down by its own weight. The sheet P is conveyed while the hanging portion is supported by the guide surface 122A of the first sheet guide 122.

  The second sheet guide 124 guides the conveyance of the sheet P conveyed in the second conveyance section. The second paper guide 124 includes a flat guide surface 124A. A guide surface 124A of the second paper guide 124 is provided in parallel with the chain 112 traveling in the second transport section. Accordingly, the guide surface 124A of the second paper guide 124 is provided to be inclined. The paper P transported in the second transport section is transported along the guide surface 124A of the second paper guide 124, and is transported while sliding on the guide surface 124A of the second paper guide 124.

[Hot air blowing unit]
The warm air blowing unit 130 blows warm air on the print surface of the paper P conveyed in the first conveyance section, and dries the ink.

  FIG. 4 is a front view showing a schematic configuration of the hot air blowing unit.

  As shown in FIG. 4, the hot air blowing unit 130 includes a plurality of blowers 132 arranged at regular intervals along the conveyance path of the paper P, and a plurality of heaters 134 arranged between the blowers 132. It is prepared for.

(Blower)
FIG. 5 is a cross-sectional view illustrating a schematic configuration of the blower.

  As shown in FIG. 5, the blower 132 includes a horizontally long box-shaped housing 136, and includes a plurality of fans 138 inside the housing 136. The blower 132 is disposed such that the longitudinal direction of the housing 136 is orthogonal to the transport direction of the paper P and parallel to the guide surface 122A.

  The housing 136 includes an air inlet 140 at the ceiling and a nozzle 142 at the tip. As shown in FIG. 3, the nozzle 142 has a slit-shaped outlet 142A. The outlet 142A has a length at least equal to the width of the paper P. The blower 132 is disposed so that the air outlet 142A faces the guide surface 122A. Thus, when the blower 132 is driven, wind is blown out from the nozzle 142 toward the guide surface 122A.

  The fan 138 is an example of a blowing unit. A plurality of fans 138 are arranged at regular intervals along the longitudinal direction of the housing 136. The fan 138 is driven to rotate by a motor (not shown). An arrow FR shown in FIG. 5 is the rotation direction of the fan 138. As the fan 138 rotates, the air introduced from the air inlet 140 is blown toward the nozzle 142. Thereby, the wind blows out from the slit-like nozzle 142 in a curtain shape.

  A shutter 144 that opens and closes the nozzle 142 is provided inside the housing 136. The shutter 144 includes a rotating shaft 144A and a shutter blade 144B. The shutter blade 144B is integrally attached to the rotating shaft 144A. The rotating shaft 144A is driven to rotate by a motor (not shown). The arrow SR shown in FIG. 5 is the rotation direction of the rotating shaft 144A. By rotating the rotating shaft 144A, the shutter blade 144B rotates and opens and closes the flow path following the nozzle 142.

  In FIG. 5, the state of the shutter 144 indicated by a solid line is a “closed” state, and the state of the shutter 144 indicated by a broken line is an “open” state. The rotating shaft 144A rotates at 90 ° intervals. Each time the rotating shaft 144A rotates 90 °, the shutter 144 shifts from “open” to “closed” and from “closed” to “open”. By opening and closing the shutter 144, the blowing of wind from the nozzle 142 is turned ON / OFF.

  The blower 132 configured as described above is arranged so that the slit-like nozzle 142 is orthogonal to the transport direction Y of the paper P. Further, the nozzle 142 is disposed so as to be positioned at a specified height from the guide surface 122A of the first paper guide 122. Further, the hot air is arranged to be blown out perpendicularly from the nozzle 142 with respect to the guide surface 122A of the first paper guide 122. An arrow BD shown in FIG. 5 is a hot air blowing direction.

  Note that a point BP shown in FIG. 5 is a hot air blowing position on the guide surface 122A. That is, it is a position where hot air blown from the nozzle 142 is blown on the guide surface 122A. When hot air is blown perpendicularly from the nozzle 142 to the guide surface 122A of the first paper guide 122, the arrangement position of the nozzle 142 is set to the blowing position BP. More specifically, the center position of the nozzle 142 with respect to the transport direction is set to the blowing position BP.

(heater)
The heater 134 is arrange | positioned between each air blower 132, as shown in FIG. The heater 134 has a length that is at least equal to the width of the paper P. The heater 134 has a heating surface that dissipates heat, and the heating surface is positioned at a predetermined height from the guide surface 122A of the first paper guide 122 and is on the guide surface 122A of the first paper guide 122. It arrange | positions so that it may oppose. Such a heater 134 is constituted by, for example, an infrared heater.

  The hot air blowing unit 130 configured as described above drives the heater 134 and the fan 138 of the blower 132 to blow hot air from the nozzle 142 of each blower 132. Hot air is blown vertically from each nozzle 142 toward the guide surface 122A of the first paper guide 122. The blowing of hot air from each nozzle 142 is individually turned ON / OFF by individually controlling the shutter 144 provided in each blower 132.

(Paper detection sensor)
The sheet detection sensor 150 is installed at a specified origin position and detects the sheet P passing through the origin position.

  The origin position is set on the transport path of the paper P transported by the chain delivery 110 and is set upstream of the hot air blowing unit 130 with respect to the transport direction Y of the paper P.

  The paper detection sensor 150 detects the gripper 114 and detects that the leading edge of the paper P has reached the origin position. The sheet detection sensor 150 includes a light projecting unit 150A and a light receiving unit 150B. The light projecting unit 150 </ b> A and the light receiving unit 150 </ b> B are arranged above and below the conveyance path of the paper P. The light projecting unit 150A and the light receiving unit 150B receive the light emitted from the light projecting unit 150A by the light receiving unit 150B. When the gripper 114 and the paper P pass through the installation position of the paper detection sensor 150, the light emitted from the light projecting unit 150A is blocked by the gripper 114 and the paper P. Therefore, by detecting that the light is not detected by the light receiving unit 150B, it is possible to detect that the paper P has passed the origin position.

  The ink drying unit 100 is configured as described above. In the process of being conveyed by the chain delivery 110, the paper P is dried by blowing hot air, which is a drying air, onto the print surface.

  The warm air is blown against the paper P by the air blowing from the nozzle 142, and the air blowing from the nozzle 142 is controlled according to the position of the paper P. This will be described in detail later.

<Accumulation part>
The stacking unit 60 stacks the sequentially discharged sheets P at one place. As shown in FIGS. 1 and 2, the stacking unit 60 includes a stacking device 62 that receives and stacks the paper P conveyed from the ink drying unit 100 by the chain delivery 110.

  The chain delivery 110 releases the paper P at a predetermined stacking position. The stacking device 62 includes a stacking tray 62A, receives the paper P released from the chain delivery 110, and stacks the sheets P on the stacking tray 62A.

<Maintenance department>
The maintenance unit 70 performs maintenance of the inkjet heads 46C, 46M, 46Y, and 46K provided in the printing unit 40. As shown in FIG. 2, the maintenance unit 70 mainly wipes the nozzle surfaces of the inkjet heads 46C, 46M, 46Y, and 46K and the nozzle surfaces of the inkjet heads 46C, 46M, 46Y, and 46K. And a cleaning device 74 for cleaning.

  The cap device 72 includes caps 72C, 72M, 72Y, 72K for each of the inkjet heads 46C, 46M, 46Y, 46K. Each cap 72C, 72M, 72Y, 72K individually covers the nozzle surface of the corresponding inkjet head 46C, 46M, 46Y, 46K.

  Capping is performed by moving the inkjet heads 46C, 46M, 46Y, and 46K to predetermined cap positions. As described above, the inkjet heads 46C, 46M, 46Y, and 46K are mounted on the carriage and provided to be movable. The inkjet heads 46C, 46M, 46Y, and 46K move to the cap position by moving the carriage.

  The carriage is provided so as to be horizontally movable along the rotation axis of the print drum 42. The ink jet heads 46C, 46M, 46Y, and 46K are provided so as to be movable between the cap position and the print position by the movement of the carriage. The inkjet heads 46C, 46M, 46Y, and 46K are arranged on the transport path of the paper P by the print drum 42 by being positioned at the print position. Further, by being located at the cap position, it is arranged immediately above the caps 72C, 72M, 72Y, 72K.

  The carriage is provided with an elevating mechanism for elevating and lowering each inkjet head 46C, 46M, 46Y, 46K in a direction perpendicular to the nozzle surface. The inkjet heads 46C, 46M, 46Y, 46K positioned at the cap position are lowered by the lifting mechanism, so that the nozzle surfaces are covered with the caps 72C, 72M, 72Y, 72K.

  The cleaning device 74 includes cleaners 74C, 74M, 74Y, and 74K that individually clean the nozzle surfaces of the inkjet heads 46C, 46M, 46Y, and 46K. Each cleaner 74C, 74M, 74Y, 74K includes a wiping member that wipes the nozzle surface. The wiping member is composed of, for example, a blade or a web, and is provided so as to be able to advance and retreat with respect to the nozzle surface. The cleaning device 74 is disposed on the movement path of the inkjet heads 46C, 46M, 46Y, and 46K by the carriage. In each of the inkjet heads 46C, 46M, 46Y, and 46K, the wiping member is pressed against the nozzle surface in the process of moving from the cap position to the printing position by the carriage, and the nozzle surface is wiped off.

  The maintenance unit 70 is configured as described above. As described above, capping by the cap device 72 is performed by moving the inkjet heads 46C, 46M, 46Y, and 46K to the cap position. The inkjet heads 46C, 46M, 46Y, and 46K move to the cap position and then descend to a predetermined position, so that the nozzle surface is covered with the caps 72C, 72M, 72Y, and 72K. Capping is performed when the use of the inkjet heads 46C, 46M, 46Y, 46K is stopped for a certain period of time, such as when the power is turned off or during standby. Further, purging or preliminary discharge (also referred to as flushing), which is one of maintenance, is performed by the cap device 72.

  Cleaning of the nozzle surface by the cleaning device 74 is performed by moving the inkjet heads 46C, 46M, 46Y, 46K from the cap position to the print position. Each of the cleaners 74C, 74M, 74Y, and 74K provided in the cleaning device 74 presses and contacts the wiping member against the nozzle surfaces of the inkjet heads 46C, 46M, 46Y, and 46K that move from the cap position toward the print position. Wipe the nozzle surface with a wiping member.

  Maintenance is automatically performed at a preset timing. Moreover, it is enforced according to the instruction | indication from an operator. In the maintenance performed automatically, the execution timing is defined for each type of maintenance. The execution timing is defined by, for example, the elapsed time from the previous maintenance, the number of prints, and the like.

《Inkjet printer control system》
FIG. 6 is a block diagram showing a schematic configuration of a control system of the ink jet printer.

  As shown in the figure, the inkjet printer 1 includes a computer 200 as a control unit. All operations of the inkjet printer 1 are controlled by the computer 200. That is, paper feeding from the paper feeding unit 10, conveyance of the fed paper P, application of pretreatment liquid in the processing liquid coating unit 20, drying of the paper P in the processing liquid drying unit 30, and printing in the printing unit 40 Under the control of the computer 200, all processes such as image printing, reading of the printed image, drying of the paper P in the ink drying unit 100, discharge of the paper P, and stacking of the paper P in the stacking unit 60 are performed. To be implemented. Maintenance is also performed under the control of the computer 200.

  The computer 200 functions as a control unit that controls each unit of the inkjet printer 1 by executing a predetermined control program.

  The computer 200 includes a communication unit 202 for communicating with an external device, an operation unit 204 for operating the inkjet printer 1, a display unit 206 for displaying various information, a storage unit 208 for storing various data, and the like. Is connected.

  The operation unit 204 includes, for example, operation buttons, a keyboard, a mouse, a touch panel, and the like. The display unit 206 is configured by a display device such as a liquid crystal display, for example. The storage unit 208 is configured by a storage device such as a hard disk drive, for example. A control program executed by the computer 200 and various data necessary for control are stored in the storage unit 208. The image data to be printed is taken in from an external device such as a host computer via the communication unit 202.

  Further, the computer 200 functions as an image processing unit by executing a predetermined image processing program. The image processing unit performs processing for converting image data to be printed into a data format that can be handled by the inkjet printer 1. Specifically, for example, a process of converting image data expressed in RGB format into dot arrangement data of each color of cyan (C), magenta (M), yellow (Y), and black (K) is performed. The computer 200 drives the inkjet heads 46C, 46M, 46Y, and 46K based on the generated dot arrangement data, and prints an image on the paper P.

  Furthermore, the computer 200 functions as a blowing control unit 210 that controls the blowing of hot air from the hot air blowing unit 130 by executing a predetermined control program.

  FIG. 7 is a block diagram of a computer that functions as a balloon control unit.

  The balloon control unit 210 is an example of a balloon control unit. The blowing control unit 210 controls the driving of the hot air blowing unit 130 according to the position of the paper P conveyed in the first conveyance section, and individually controls the blowing of hot air from each nozzle 142. A specific control method will be described in detail later.

  Here, the position of the paper P is obtained based on the output from the paper detection sensor 150. The computer 200 functions as the paper position detection unit 212 by executing a predetermined position detection program.

  The paper position detection unit 212 is an example of a paper position detection unit, and detects the leading edge position and the trailing edge position of the paper P with reference to the origin position. Specifically, the leading edge position and the trailing edge position of the sheet P with respect to the origin position are detected based on the conveyance speed of the sheet P by the chain delivery 110, the output of the sheet detection sensor 150, and the length of the sheet P. To do. For example, if the transport speed of the paper P is V [mm / sec] and the length of the paper P is PL [mm], the position of the leading edge of the paper P after t seconds is V [mm]. Further, the position of the trailing edge of the paper P is (V-PL) [mm]. Therefore, if the leading edge of the paper P is detected by the paper detection sensor 150, the positions of the leading edge and the trailing edge of the paper P can be detected from the elapsed time.

<Print processing procedure>
Next, a print processing procedure by the ink jet printer 1 according to the present embodiment will be described.

  Printing includes (a) paper feeding, (b) application of pretreatment liquid, (c) drying of pretreatment liquid, (d) printing, (e) drying of ink, (f) paper discharge, (g) stacking, It is carried out in the flow.

  When printing is started, the sheets P are fed from the sheet feeding unit 10 one by one at regular intervals.

  The pretreatment liquid is first applied to the print surface of the paper P fed from the paper supply unit 10 by the treatment liquid application unit 20.

  Next, the paper P coated with the pretreatment liquid is dried by the treatment liquid drying unit 30. The treatment liquid drying unit 30 blows warm air on the print surface of the conveyed paper P to dry the paper P.

  The dried paper P is then subjected to print processing by the printing unit 40. The printing unit 40 prints a color image on the print surface by ejecting ink droplets from the inkjet heads 46C, 46M, 46Y, and 46K toward the paper P being conveyed.

  The paper P on which the image is printed is then dried by the ink drying unit 100. The ink drying unit 100 performs drying processing on the paper P by blowing warm air, which is a drying air, onto the print surface of the paper P being conveyed.

  The dried paper P is conveyed to the stacking unit 60, discharged from the stacking unit 60, and stacked in a bundle.

<Ink drying process>
<First Embodiment>
As described above, in the ink drying process that is performed after printing, the blowing of hot air from each nozzle 142 is individually controlled according to the position of the paper P that is transported through the first transport section. Specifically, control is performed so that hot air is blown out immediately before the leading edge of the paper P reaches the blowing position BP, and blowing of hot air stops immediately before the trailing edge of the paper P reaches the blowing position BP. Is done.

  FIG. 8 is a conceptual diagram of control of hot air blowing. FIG. 6A shows the timing for turning on hot air blowing, and FIG. 6B shows the timing for turning off hot air blowing.

[Timing to turn on hot air blowing]
As shown in FIG. 8A, when the gripper 114 is the leading end of the paper P, when the gripper 114 reaches a position SP1 on the transport path, hot air blowing from the nozzle 142 is turned on. This position SP1 is set immediately before the blowing position BP, and is set at a position separated from the blowing position BP by a distance D1. The distance D1 is determined in consideration of the flapping of the paper P caused by starting the blowing. That is, if the distance D1 is set too large, the blown wind enters under the paper P from the leading end side of the paper P, causing flapping. Therefore, the distance D1 is set in a range where the fluttering is within the allowable range. Note that the flapping of the paper varies depending on the paper size, the paper thickness, the speed at which the paper is conveyed, the amount of air blown from the nozzles, and the like.

[Timing to turn off hot air blowing]
As shown in FIG. 8B, when the trailing edge of the paper P reaches the position SP2 on the transport path, the blowing of hot air from the nozzle 142 is turned off. This position SP2 is set immediately before the blowing position BP, and is set at a position separated from the blowing position BP by a distance D2. The distance D2 is determined in consideration of the flapping of the paper P caused by starting the blowing. As in the case where the balloon is turned on, if the distance D2 is set too large, the blown wind enters under the sheet P from the rear end side of the sheet P and causes flapping. Therefore, the distance D2 is set in a range where the fluttering is within the allowable range.

  Note that the positions of the leading edge and the trailing edge of the sheet P to be conveyed can be obtained from the conveying speed of the sheet P and the length of the sheet P as described above.

[Individual control of hot air blowing]
As described above, the blowing of hot air from the nozzles 142 is individually controlled for each nozzle 142.

  FIGS. 9 and 10 are state transition diagrams in the case of individually controlling the blowing of hot air from the nozzles.

  9 and 10, N1, N2,..., N10 are assigned in order from the upstream side in the transport direction Y in order to distinguish the nozzles of each blower.

  In the following description, the nozzles N1 to N10 of each blower are distinguished as a first nozzle N1, a second nozzle N2,..., A tenth nozzle N10 in order from the upstream side. Further, the blowing positions of the nozzles N1, N2,..., N10 of each blower are distinguished as BP1, BP2,. Further, a plurality of continuously conveyed sheets are distinguished from the first side in order from the first side as the first sheet P1, the second sheet P2,.

  9 and 10, nozzles with wavy lines indicate nozzles in a state where hot air blowing is ON. In addition, nozzles without wavy lines indicate nozzles in a state where hot air blowing is off.

  As shown in FIG. 9A, until the leading edge of the leading sheet P1 reaches the position immediately before the blowing position BP1 of the first nozzle N1, all the hot air blown from each nozzle N1 to N10 It is turned off.

  As shown in FIG. 9B, when the center of the leading sheet P1 reaches the position immediately before the blowing position BP1 of the first nozzle N1, the blowing of hot air from the first nozzle N1 is turned on. Note that hot air blowing from the other nozzles N2 to N10 remains OFF.

  As shown in FIG. 9C, as the leading sheet P1 is transported to the downstream side, the blowing from the downstream nozzles is sequentially turned on.

  Then, as shown in FIG. 10A, when the rear end of the leading sheet P1 is conveyed to a position immediately before the blowing position BP1 of the first nozzle N1, hot air is blown from the first nozzle N1. It is turned off.

  Thereafter, as shown in FIG. 10B, the blowing is sequentially turned on at the downstream side of the sheet P1, while the blowing is sequentially turned off at the upstream side of the sheet P1.

  When the leading end of the second sheet P2, which is the next sheet, is transported to the position immediately before the spraying position, the nozzle whose balloon is turned off is turned on again. For example, as shown in FIG. 10 (C), the first nozzle N1 once turned off is transported to the position immediately before the blowing position BP1 by the leading edge of the second sheet P2, which is the next sheet. Then, the balloon is turned on again.

  FIG. 11 is an ON / OFF timing chart of the blowout of each nozzle when the hot air blowout from the nozzles is individually controlled. The horizontal axis indicates the elapsed time.

  In FIG. 11, point T1 indicates the timing at which the leading edge of the leading sheet P1 has reached the position immediately before the blowing position BP1 of the first nozzle N1. When the leading edge of the first sheet P1 reaches the position immediately before the blowing position BP1 of the first nozzle N1, the blowing of hot air from the first nozzle N1 is turned on.

  In FIG. 11, point T2 indicates the timing at which the leading edge of the leading sheet P1 has reached the position immediately before the blowing position BP2 of the second nozzle N2. When the leading end of the first sheet P1 reaches a position immediately before the blowing position BP2 of the second nozzle N2, the blowing of hot air from the second nozzle N2 is turned on. Thereafter, when the leading edge of the leading sheet P1 reaches the position immediately before the blowing position of each nozzle, the blowing of hot air is turned on one after another.

  In FIG. 11, a point T3 indicates the timing at which the rear end of the leading sheet P1 reaches the position immediately before the blowing position BP1 of the first nozzle N1. When the rear end of the first sheet P1 reaches the position immediately before the blowing position BP1 of the first nozzle N1, the blowing of hot air from the first nozzle N1 is turned off.

  In FIG. 11, point T4 indicates the timing at which the rear end of the leading sheet P1 has reached the position immediately before the blowing position BP2 of the second nozzle N2. When the rear end of the leading sheet P1 reaches a position immediately before the blowing position BP2 of the second nozzle N2, the blowing of hot air from the second nozzle N2 is turned off. Thereafter, when the rear end of the leading sheet P1 reaches a position immediately before the blowing position of each nozzle, the blowing of hot air is successively turned off.

  In FIG. 11, a point T5 indicates the timing at which the leading edge of the next sheet P2 reaches the position immediately before the blowing position BP1 of the first nozzle N1. When the leading edge of the next sheet P2 reaches the position immediately before the blowing position BP1 of the first nozzle N1, the blowing of hot air from the first nozzle N1 is turned on again.

  In FIG. 11, a point T6 indicates the timing at which the leading edge of the next sheet P2 reaches the position immediately before the blowing position BP2 of the second nozzle N2. When the leading edge of the next sheet P2 reaches the position immediately before the blowing position BP2 of the second nozzle N2, the blowing of hot air from the second nozzle N2 is turned on again. Thereafter, when the leading edge of the next sheet P2 reaches the position immediately before the blowing position of each nozzle, hot air blowing is resumed one after another.

  As described above, when the leading ends of the sheets of the individual nozzles N1 to N10 are conveyed to the position immediately before the blowing positions BP1 to BP10, the blowing of hot air is turned on. When the trailing edge of the sheet is conveyed to a position immediately before the blowing positions BP1 to BP10, the hot air blowing is turned off. Thereby, it is possible to effectively prevent the blown wind from entering under the paper and causing the paper to flutter.

[Modification]
In the above embodiment, the hot air is blown out immediately before the leading edge of the paper P reaches the blowing position BP, and the blowing of hot air stops immediately before the trailing edge of the paper P reaches the blowing position BP. Although the hot air blowing from the nozzle 142 is controlled, the hot air blowing may be turned on when the leading edge of the paper P reaches the blowing position BP. Alternatively, the hot air blowing may be turned on after the leading edge of the paper P reaches the blowing position BP. Further, after the rear end of the paper P has passed the blowing position BP, the blowing of hot air from the nozzle 142 may be turned off. That is, it is only necessary to stop the blowing of the wind from the nozzle 142 until at least the trailing edge of the paper P passes the blowing position BP and the leading edge of the next paper P reaches the blowing position BP. .

  Note that, as in the above embodiment, the hot air is blown on the entire sheet P passing through the blowing position BP by turning on the blowing of hot air immediately before the leading edge of the paper P reaches the blowing position BP. And the paper P can be efficiently dried.

  Also, by turning off the blowing of hot air immediately before the trailing edge of the paper P reaches the blowing position BP, the blown wind enters under the paper P from the trailing edge side of the paper P and flutters the paper P. It is possible to effectively prevent it from being lost.

<Second Embodiment>
In the first embodiment, the blowing of hot air from the nozzles is individually controlled to control the blowing of hot air onto the paper. In the present embodiment, hot air blowing from the nozzles is collectively controlled to control the blowing of hot air onto the paper.

  FIG. 12 is a conceptual diagram when controlling the blowing of hot air from the nozzles collectively.

  Of the plurality of nozzles arranged along the transport path of the paper P, the nozzle located at the uppermost stream in the transport direction Y of the paper P is referred to as the first nozzle Nf, and the nozzle located at the most downstream is referred to as the rearmost nozzle Ne. Further, the blowing position of the leading nozzle Nf is defined as the leading blowing position BPf, and the blowing position of the rearmost nozzle Ne is defined as the last trailing position BPe.

  In the present embodiment, hot air is blown from all the nozzles at the same time immediately before the leading edge of the paper P reaches the top blowing position BPf. When the trailing edge of the sheet P passes through the leading blowing position BPf, hot air blowing is stopped all at once. The stopped hot air blowing is resumed all at once just before the leading edge of the next sheet P reaches the leading blowing position BPf.

  Here, the timing for stopping the blowing of hot air is set in consideration of the flapping that occurs on the next sheet P to be conveyed and the drying efficiency. That is, if the stop period is too short, the wind enters under the next sheet P to be conveyed and causes the sheet P to be conveyed next to flutter. On the other hand, if the stop period is set too long, the hot air cannot be sufficiently applied to the paper P that has been transported first, and the drying efficiency decreases. Therefore, the timing for stopping the blowing of hot air is set in consideration of the flapping that occurs on the next sheet P to be conveyed and the drying efficiency. For example, when the interval between the front and rear sheets P is wide, the setting is made so that the hot air blowing stops after a lapse of a certain time after the trailing edge of the sheet P passes through the leading blowing position BPf. On the other hand, when the interval between the front and rear sheets P is narrow, the setting is made so that the blowing of hot air stops immediately after the trailing edge of the sheet P passes through the leading blowing position BPf.

  Further, in the present embodiment, the blowing of hot air from all the nozzles is stopped at the same time immediately before the rear end of the paper P reaches the last blowing position BPe. The stopped hot air blowing is resumed all at once when the trailing edge of the paper P passes through the last blowing position BPe.

  Here, the timing of restarting the hot air blowing is set in consideration of the flapping of the paper P caused by the restart of the hot air blowing. That is, when hot air blowing is resumed immediately after passing through the last tail blowing position BPe, the wind blown from the rear end side of the paper P that has passed through the last tail blowing position BPe into the lower side of the paper P enters. Since fluttering is induced, it is preferable to restart the blowing of hot air after the paper P is sufficiently separated.

  13 to 15 are state transition diagrams in the case where hot air blowing from the nozzles is controlled collectively.

  13 to 15, nozzles with wavy lines indicate nozzles in a state where hot air blowing is ON. In addition, nozzles without wavy lines indicate nozzles in a state where hot air blowing is off.

  As shown in FIG. 13A, the blowing of hot air from each nozzle is turned off until the leading edge of the leading sheet P1 reaches a position immediately before the leading blowing position BPf.

  As shown in FIG. 13B, when the leading edge of the leading sheet P1 reaches a position immediately before the leading blowing position BPf, hot air blowing from each nozzle is turned on all at once.

  Thereafter, as shown in FIG. 14A, when the trailing edge of the leading sheet P1 passes the leading blowing position BPf, the blowing of hot air from each nozzle is turned off all at once.

  As shown in FIG. 14B, the hot air blown off is turned on all at once when the leading edge of the second sheet P2, which is the next sheet, reaches the position immediately before the top blowing position BPf. Is done.

  As described above, when the trailing edge of the sheet transported in front passes through the leading blowing position BPf, the blowing of hot air from each nozzle is turned off all at once. The hot air blown off is turned on all at once when the leading edge of the paper conveyed behind reaches the position immediately before the top blowing position BPf.

  On the other hand, as shown in FIG. 15A, when the rear end of the leading sheet P1 reaches a position immediately before the last blowing position BPe, hot air blowing from each nozzle is turned off all at once.

  Then, as shown in FIG. 15B, when the rear end of the leading sheet P1 passes through the last blowing position BPe, the blowing is simultaneously turned on again.

  Thus, immediately before the trailing edge of the conveyed paper passes the blowing position BPe of the last nozzle Ne, the blowing of hot air from each nozzle is turned off all at once, and the blowing position BPe of the last nozzle Ne is set. When it has passed, the balloons are turned on all at once.

  FIG. 16 is a timing chart of ON / OFF of the blowout of each nozzle in the case where hot air blowout from the nozzles is controlled collectively. The horizontal axis indicates the elapsed time.

  In FIG. 16, a point t1 indicates the timing at which the leading edge of the leading sheet P1 reaches the position immediately before the leading blowing position BPf. When the leading edge of the leading sheet P1 reaches a position immediately before the leading blowing position BPf, hot air blowing from each nozzle is turned on all at once.

  In FIG. 16, a point t2 indicates the timing at which the trailing edge of the leading sheet P1 has passed the leading blowing position BPf. When the trailing edge of the leading sheet P1 passes the leading blowing position BPf, the blowing of hot air from each nozzle is turned off all at once.

  In FIG. 16, a point t3 indicates the timing at which the leading edge of the second sheet P2, which is the next sheet, has reached the position immediately before the top blowing position BPf. When the leading edge of the second sheet P2, which is the next sheet, reaches the position immediately before the top blowing position BPf, the blowing of hot air from all the nozzles is again turned on all at once.

  In this way, when the trailing edge of the paper transported in front passes through the leading blowing position BPf, the blowing of hot air from each nozzle is turned off all at once, and the leading edge of the paper transported next becomes the leading blowing. When the position immediately before the contact position BPf is reached, the hot air blowing from all the nozzles is turned on all at once.

  In FIG. 16, a point t4 indicates the timing at which the rear end of the leading sheet P1 has reached the position immediately before the last blowing position BPe. When the rear end of the first sheet P1 reaches a position immediately before the last blowing position BPe, hot air blowing from each nozzle is turned off all at once.

  In FIG. 16, a point t5 indicates the timing at which the rear end of the leading sheet P1 passes through the last blowing position BPe. When the rear end of the leading sheet P1 passes through the last blowing position BPe, the blowing of hot air from each nozzle is again turned on all at once.

  As described above, when the hot air blowing is controlled collectively, the blowing is controlled collectively based on the leading blowing position BPf and the trailing blowing position BPe. Thereby, it is possible to effectively prevent the blown wind from entering under the paper and causing the paper to flutter.

[Modification]
In the above embodiment, hot air blowing is turned on all at once immediately before the leading edge of the paper P reaches the top blowing position BPf, but the timing at which the leading edge of the paper P reaches the leading blowing position BPf. The hot air blowing may be turned on all at once. Alternatively, after the leading edge of the paper P reaches the front blowing position BPf, the hot air blowing may be turned on all at once.

  In the above embodiment, the rear end of the paper P passes through the front blowing position BPf, and then the hot air blowing is turned off all at once. However, the rear end of the paper P is at the front blowing position BPf. It is good also as a structure which turns off the blowing of a hot air all at once just before passing.

  In the above embodiment, the rear end of the paper P is configured to turn off the blowing of hot air immediately before passing the last tail blowing position BPe, but the rear end of the paper P is the last tail blowing. It is good also as a structure which turns off the blowing of a hot air simultaneously at the timing which passes position BPe. Alternatively, after the trailing edge of the paper P passes through the last tail blowing position BPe, the hot air blowing may be turned off all at once. In this case, for example, after turning OFF all at once, the signals are turned ON all at once after a predetermined time.

<Other embodiments>
[Nozzle variants]
In the said embodiment, although it is set as the structure which blows off the wind for drying from the nozzle which has a slit-shaped blower outlet, the form of a nozzle is not limited to this.

  FIG. 17 is a perspective view showing another form of the nozzle.

  The form shown in the figure is configured to blow drying air from a plurality of circular outlets 142A arranged at a constant pitch. The outlets 142A are arranged in a line at least as long as the width of the paper P. The blower 132 is disposed so that the air outlet 142A faces the guide surface 122A. Thus, when the blower 132 is driven, wind is blown out from the nozzle 142 toward the guide surface 122A.

  In addition, it can also be set as the structure provided with two or more slit-shaped outlets in one air blower. For example, two slit-shaped outlets can be provided in parallel. In this case, the blowing position is the blowing position of the blower, which is the blowing position of the wind blown from the blowout port located on the upstream side with respect to the sheet conveyance direction.

[Variation 1 of the hot air blowing unit]
FIG. 18 is a cross-sectional view showing another example of the hot air blowing unit.

  The hot air blowing unit 160 shown in the figure includes one blower 162 as an air source, and blows the wind sent from the one blower 162 onto the paper P.

  As shown in FIG. 18, the hot air blowing unit 160 includes a single box-shaped chamber 164. The chamber 164 includes a blowout surface 164A that blows out air at a lower portion, and an air inlet 164B at an upper portion.

  The blowing surface 164A of the chamber 164 is provided to face the guide surface 122A of the first paper guide 122 and to be parallel to the guide surface 122A of the first paper guide 122. The blowing surface 164A is provided with a plurality of nozzles 166 at regular intervals along the transport direction Y of the paper P. The nozzle 166 has a slit-shaped outlet 166A extending in a direction orthogonal to the transport direction Y of the paper P.

  A duct 168 is connected to the air inlet 164 </ b> B of the chamber 164. The duct 168 is connected to the blower 162. The duct 168 is provided with a damper 170 that adjusts the air volume from the blower 162 and functions as a valve.

  A heater 172 for heating the air in the chamber 164 is provided in the chamber 164. A plurality of heaters 172 are arranged at regular intervals along the transport direction Y of the paper P.

  When the blower 162 is driven, the hot air blowing unit 160 of the present embodiment configured as described above blows hot air from each nozzle 166. The hot air is blown out perpendicularly to the guide surface 122A of the first paper guide 122, and is blown against the print surface of the paper P conveyed in the first conveyance section.

  Further, the hot air blowing unit 160 stops the blowing by closing the damper 170 functioning as a valve, and the blowing from each nozzle 166 is turned off collectively. As described above, in the hot air blowing unit 160 of the present embodiment, the blowing of hot air from the nozzles 166 is turned ON / OFF at once, so that the blowing is controlled in a lump.

  A shutter mechanism can be provided for each nozzle 166. Thereby, it is possible to control the blowout in units of nozzles.

[Variation 2 of the hot air blowing unit]
FIG. 19 is a cross-sectional view showing another example of the hot air blowing unit.

  The hot air blowing unit 180 shown in the figure includes a compressed air source 182 and blows the compressed air supplied from the compressed air source 182 onto the paper P.

  As shown in FIG. 19, a plurality of nozzles 184 are arranged at regular intervals along the transport direction Y of the paper P. Each nozzle 184 includes a slit-shaped outlet, and blows out compressed air vertically toward the guide surface 122A of the first paper guide 122. A heater 186 is disposed between the nozzles 184.

  Each nozzle 184 is connected to the compressed air source 182 via a pipe 188. In each pipe 188 communicating with each nozzle 184, an electromagnetic valve 190 serving as a valve is individually arranged. The discharge of compressed air from each nozzle 184 is controlled by this electromagnetic valve 190.

  In the hot air blowing unit 180 of the present embodiment configured as described above, when the electromagnetic valve 190 is opened, compressed air is blown out from the nozzle 184 and blown against the print surface of the paper P being conveyed in the first conveying section. . Since the electromagnetic valve 190 is provided for each nozzle 184, the blowing can be individually controlled for each nozzle 184.

  In this example, a common compressed air source is used for each nozzle, but a compressed air source may be provided for each nozzle individually.

[Variation 3 of the hot air blowing unit]
In the above embodiment, the heaters 134 are arranged between the blowers 132, but the heaters may be arranged inside the blowers 132.

  Moreover, it is good also as a structure which arrange | positions the heater 134 between each air blower 132, and also arrange | positions a heater also inside each air blower 132. FIG.

[Other examples of transport means]
In the above embodiment, the chain delivery is adopted as the paper transporting means, but the transporting means is not limited to this. Any form that can grip the leading edge of the sheet and convey it along the guide surface is acceptable.

[ON / OFF of hot air blowing]
In the above embodiment, the opening / closing of the shutter 144 provided corresponding to each nozzle 142 is controlled to turn on / off the blowing of hot air from each nozzle 142, but the drive of the fan 138 is turned on / off. It is also possible to turn off and turn on / off hot air blowing from each nozzle 142.

(Paper position detection)
In the above embodiment, the leading edge of the paper passing through the origin position is detected, and the paper position is detected from the paper conveyance speed and the paper length, but the method of detecting the paper position is as follows: It is not limited to this. For example, a paper detection sensor may be provided for each nozzle to detect paper passing through a certain position.

[Application to other than inkjet printers]
In the above embodiment, the case where the present invention is applied to an inkjet printer has been described as an example. However, the application of the present invention is not limited to this. The paper drying device can be configured as a single unit.

  In the above embodiment, the case where the printed paper is dried is described as an example. However, the paper after the pretreatment liquid is applied can also be dried with the same configuration.

  Further, when the present invention is applied to an ink jet printer, only the paper printed on both sides may be dried by the method of the present invention. In this case, the paper printed only on one side is conveyed while adsorbing the paper on the guide surface. Therefore, in this case, the guide means is provided with a separate suction mechanism. This suction mechanism is operated only when the paper printed only on one side is dried. Further, when a paper printed on only one side is dried, the blowout control is not performed and the paper is always blown out. An operator inputs whether the paper is printed on both sides via the operation unit.

  DESCRIPTION OF SYMBOLS 1 ... Inkjet printer, 10 ... Paper feed part, 12 ... Paper feed apparatus, 12A ... Paper feed tray, 14 ... Feeder board, 16 ... Paper feed drum, 20 ... Treatment liquid application part, 22 ... Treatment liquid application drum, 23 ... Gripper, 24 ... processing liquid coating device, 30 ... processing liquid drying section, 32 ... processing liquid drying drum, 33 ... gripper, 34 ... warm air blower, 40 ... printing section, 42 ... printing drum, 43 ... gripper, 44 ... head Unit: 46C, 46M, 46Y, 46K ... inkjet head, 48 ... scanner, 60 ... stacking unit, 62 ... stacking device, 62A ... stacking tray, 70 ... maintenance unit, 72 ... cap device, 72C, 72M, 72Y, 72K ... Cap, 74 ... Cleaning device, 74C, 74M, 74Y, 74K ... Cleaner, 100 ... Ink drying section, 110 ... Chain detent Burr, 112 ... Chain, 114 ... Gripper, 114A ... Gripper body, 114B ... Grip claw, 120 ... Paper guide, 122 ... First paper guide, 122A ... Guide surface of first paper guide, 124 ... Second paper guide, 124A ... Guide surface of second paper guide, 130 ... warm air blow unit, 132 ... blower, 134 ... heater, 136 ... housing, 138 ... fan, 140 ... air inlet, 142 ... nozzle, 142A ... nozzle outlet, 144 ... Shutter, 144A ... Rotating shaft of shutter, 144B ... Shutter blade, 150 ... Paper detection sensor, 150A ... Light projecting part, 150B ... Light receiving part, 160 ... Hot air blowing unit, 162 ... Blower, 164 ... Chamber, 164A ... Chamber 164B ... Air inlet of the chamber, 166 ... Nozzle, 166A ... Slurry outlet, 168 ... duct, 170 ... damper, 172 ... heater, 180 ... hot air blowing unit, 182 ... compressed air source, 184 ... nozzle, 186 ... heater, 188 ... piping, 190 ... electromagnetic valve, 200 ... computer , 202, communication unit, 204, operation unit, 206, display unit, 208, storage unit, 210, blowing control unit, 212, paper position detection unit, BP, blowing position, BP 1 to BP 10, blowing position, BPf,. First blowing position, BPe ... last tail blowing position, N1 to N1 ... first nozzle to tenth nozzle, Nf ... first nozzle, Ne ... last nozzle, P ... paper, P1 ... paper on paper, P2 ... two sheets Eye paper, P3 ... 3rd paper

Claims (11)

In a paper drying device for drying sheets of paper,
A guide means having a guide surface for guiding the conveyance of the paper;
A plurality of grippers that travel at regular intervals along a predetermined travel route, gripping the leading edge of the paper with the grippers, and transporting the paper continuously along the guide surface;
A blower that blows the wind against the paper transported by the transport unit by blowing out the wind from the nozzle toward the guide surface;
Paper position detecting means for detecting the position of the paper conveyed by the conveying means;
Blowout control means for controlling the driving of the blower means in accordance with the position of the paper conveyed by the conveyance means, and for controlling the blowing of the wind from the nozzle;
With
When the position on the guide surface to which the wind blown from the nozzle is blown is a blowing position,
The blowing control unit stops blowing the wind from the nozzles at least after the trailing edge of the sheet passes through the blowing position until the leading edge of the next sheet reaches the blowing position. ,
Paper drying device. The blowing control means stops the blowing of the wind from the nozzle until just before the leading edge of the next sheet reaches the blowing position.
The paper drying apparatus according to claim 1. The blowing control means stops blowing the wind from the nozzle immediately before the trailing edge of the paper passes the blowing position.
The paper drying apparatus according to claim 1 or 2. A plurality of the nozzles are arranged at regular intervals along the conveyance path of the paper,
The blowing control unit individually controls the blowing of the wind from the nozzle.
The paper drying apparatus according to any one of claims 1 to 3. A plurality of the nozzles are arranged at regular intervals along the conveyance path of the paper,
When the nozzle located at the uppermost stream with respect to the transport direction of the paper is the leading nozzle, and the position where the wind blown from the leading nozzle is blown is the leading blowing position,
The blowing control means blows the wind from the nozzles at least after the trailing edge of the sheet passes through the leading blowing position until the leading edge of the next sheet reaches the leading blowing position. Stop all at once,
The paper drying apparatus according to any one of claims 1 to 3. When the nozzle located on the most downstream side with respect to the conveyance direction of the paper is the rearmost nozzle, and the position where the air blown from the rearmost nozzle is blown is the last blown position,
The blowing control means is configured so that the air flow from the nozzle is at least from immediately before the trailing edge of the sheet passes through the last blowing position until the trailing edge of the sheet finishes passing through the last blowing position. Stop all the balloons at once,
The paper drying apparatus according to claim 5. The blowing means is
An air source for supplying air to the nozzle;
A valve for opening and closing a flow path of air sent from the air source to the nozzle;
And opening and closing the valve to control the blowing of the wind from the nozzle,
The paper drying apparatus according to any one of claims 1 to 6. The blowing means is
A fan for blowing air toward the nozzle;
A shutter for opening and closing the nozzle;
And opening and closing the shutter to control the blowing of the wind from the nozzle,
The paper drying apparatus according to any one of claims 1 to 6. The nozzle blows out the wind perpendicular to the guide surface;
The spray position is set to the installation position of the nozzle.
The paper drying apparatus according to any one of claims 1 to 8. The transport means is configured by chain delivery.
The paper drying apparatus according to any one of claims 1 to 9. A print section that prints on a sheet of paper by an inkjet method;
The paper drying apparatus according to any one of claims 1 to 10, wherein the paper printed by the printing unit is dried.
Inkjet printer equipped with.

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