JP2016069163A - Liquid discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the completion time while keeping the height of the curl generated in a recording medium equal to or less than the allowable height of the curl.SOLUTION: A printer comprises a holding mechanism which holds one or a plurality of sheets while keeping the height of the curl generated in the one or the plurality of sheets equal to or less than the allowable height of the curl, and a control part. The control part executes determination processing for determining one or more separating positions for separating the plurality of sheets related to a recording job into a plurality of sheet groups and the stand-by time at each separating position on the basis of the liquid amount discharged to each of the plurality of sheets, conveyance processing for conveying the plurality of sheets to the holding mechanism for each sheet group, and movement processing for moving the plurality of sheets to a reception tray after standing by for the stand-by time in the holding mechanism for each sheet group. The determination processing sets the separating selection range constituted by a plurality of temporary separating positions with respect to each separating position, and determines the temporary separating position at which the completion time required from the recording start of a plurality of recording media related to the recording job to the finish of movement of the plurality of recording media to the reception tray becomes the minimum among the plurality of temporary separating positions as the separating position.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a liquid ejecting apparatus that records an image by ejecting liquid onto a recording medium.

  Patent Document 1 discloses a sheet stacking apparatus including a stacking tray on which sheets (recording media) are stacked, and a pair of sheet support units that are disposed above the stacking tray and temporarily hold sheets discharged by discharge rollers. Is described. The pair of sheet support means of the sheet stacking device has a U-shape including a lower guide surface, a side guide, and an upper guide surface, and is provided to face both ends in the sheet width direction. The pair of sheet support means is configured to be movable between a first position where the sheet can be held and a second position where the sheet lower surface is not supported, and the sheet is discharged from the discharge roller at the first position. After holding the sheet, it moves to the second position and drops the sheet onto the stacking tray.

JP 2003-246525 A

  In the sheet stacking apparatus described in Patent Document 1, for example, when a sheet on which liquid is discharged is held by a pair of sheet support means, the sheet is supported by the discharged liquid while the sheet support means holds the sheet. Even if the curl is generated, the curl is suppressed to be less than the allowable height of the curl by the lower guide surface and the upper guide surface of the sheet supporting means. On the other hand, since the stacking tray does not have a member for suppressing the curl to be below the allowable curl height, the sheet curl cannot be suppressed after the sheets are stacked on the stacking tray. For this reason, in order to suppress the progress of curling on the stacking tray, it is important how long the sheet support means waits.

  Patent Document 1 describes that a plurality of sheets are held together by a pair of sheet support means and then dropped onto a stacking tray. However, for example, when the number of sheets is larger than the number of sheets that can be held by the pair of sheet support means, the curl generated on the sheets is kept below the allowable curl height until the movement of the plurality of sheets to the stacking tray is completed. In order to shorten the completion time required for the above, there is no specific description of how to divide and convey the plurality of sheets and how long the plurality of sheets are held by the sheet support means.

  Accordingly, an object of the present invention is to provide a liquid ejecting apparatus capable of shortening the completion time while keeping the curl generated in the recording medium to be equal to or less than the allowable curl height.

  The liquid discharge apparatus of the present invention can store a liquid discharge head for discharging a liquid, a transport mechanism for transporting a recording medium on which an image is recorded by the liquid discharge head, and a recording medium having a predetermined number or less. And a first surface and a second surface disposed at a predetermined distance that is a distance equal to or less than an allowable height of curl in the vertical direction from the first surface, and is transported by the transport mechanism A holding mechanism for holding a plurality of recording media between the first surface and the second surface, a support position at which the first surface supports the plurality of recording media, and the first surface Is arranged below the holding mechanism and a moving mechanism that moves at least the first surface so as to take a non-supporting position that does not support the plurality of recording media, and the plurality of recording media are stacked vertically. A receiving tray for receiving the plurality of It said receiving tray and the liquid discharge head having a support surface for supporting the lower surface of the recording medium most underlying of the medium, the transport mechanism, and, and a control means for controlling the moving mechanism. The control means includes one or more delimiters that divide a plurality of recording media related to a recording job, which is a series of processes corresponding to a recording command, into a plurality of groups each composed of a predetermined number of recording media or less. A determination process for determining a position and a waiting time at each separation position based on at least the amount of liquid ejected to each of the plurality of recording media, and the first surface takes the support position, A transport process for transporting the plurality of recording media between the first surface and the second surface for each group by separating the plurality of recording media at one or more separation positions determined in the determination process; One or more recording media belonging to the group located between the first surface and the second surface are waited for the waiting time, and then the first surface is moved from the support position to the non-support position. Move process and And in the determination process, a delimiter selection range configured by a plurality of temporary delimiter positions for setting the number of recording media belonging to each group to be equal to or less than the predetermined number of sheets is set for each delimiter position, Among the plurality of temporary separation positions in the separation selection range, the completion time required from the start of recording of the plurality of recording media related to the recording job to the end of moving the plurality of recording media to the receiving tray is minimized. Is determined as the delimiter position.

  According to this, even if the plurality of recording media related to the recording job is larger than the predetermined number of sheets stored in the holding mechanism, the plurality of recording media are divided into a plurality of groups equal to or less than the number of sheets stored and conveyed to the holding mechanism for each group. Is possible. Then, when one or more recording media belonging to each group are placed on standby between the first surface and the second surface, even if curling occurs in the recording medium, the curling is restricted to an allowable height or less. Is possible. The provisional separation position that minimizes the completion time required to move the plurality of recording media to the receiving tray from the start of recording of the plurality of recording media related to the recording job is determined as the separation position. For this reason, it is possible to shorten the completion time while keeping the curl generated in the recording medium below the allowable curl height.

  In the present invention, the control means, in the determination process, on the condition that the number of the separation position is a specific number that is not less than a minimum number and not less than a predetermined number that is not less than the minimum number, and the separation position and the separation position It is preferable to determine the waiting time. This makes it possible to easily determine the break position and the standby time.

  Also, in the present invention, the control means, in the determination process, sets the temporary positions within the delimiter selection range on the condition that the number of delimiter positions is a specific number that is greater than or equal to the minimum number and less than or equal to the predetermined number. Among the separation positions, it is preferable that the provisional separation position at which the amount of liquid ejected to the uppermost recording medium when received by the receiving tray is minimized is determined as the separation position. This makes it possible to easily determine the break position.

  In the present invention, it is preferable that the specific number is the minimum number. This makes it possible to more easily determine the break position.

  In the present invention, the control means may determine the waiting time based on the amount of the liquid ejected to the uppermost recording medium when received in the receiving tray in the determining process. preferable. Thereby, the waiting time in the holding mechanism can be effectively reduced.

  In the present invention, it is preferable that the standby time increases as the amount of the liquid ejected onto the recording medium increases. Thereby, the standby time can be determined with high accuracy.

  Further, in the present invention, the control means, in the determination process, on the condition that the number of the separation positions is a specific number that is not less than the minimum number and not less than a predetermined number that is not less than the minimum number. For each of the plurality of temporary delimiter positions, the amount of liquid ejected in each region in one or a plurality of regions defined in each recording medium, and the plurality of recording media in any of the holding mechanism and the receiving tray Two or more recordings including the uppermost recording medium among the plurality of recording media conveyed between the first surface and the second surface based on the relative position of the recording medium An individual standby time for each area of the medium is calculated, a maximum individual standby time that is a maximum value of a plurality of the individual standby times is extracted for each group, and a total standby of these maximum individual standby times Calculated between, it is preferable to determine the provisional delimiting position of the minimum value of the plurality of the total wait times are calculated for the plurality of temporary separated position to the break position. This makes it possible to easily determine the break position.

  Further, in the present invention, the control means, in the determination process, each of the maximum individual waiting time for each of the groups related to the minimum value among the plurality of total waiting times calculated for the plurality of temporary delimiter positions. Is preferably determined as the waiting time. Thereby, each individual standby time is calculated based on the amount of liquid ejected for each region and the relative position of the recording medium among the plurality of recording media in any of the holding mechanism and the receiving tray. Considering that the individual standby time at this time is calculated based on the relative position of the recording medium, the curling of the recording medium is suppressed by the weight of the recording medium above the recording medium, The individual standby time can be effectively shortened. The maximum individual standby time among the plurality of individual standby times is extracted for each group, and the total standby time of these maximum individual standby times is calculated. Then, each of the maximum individual standby times for each group related to the minimum value among the plurality of total standby times calculated for the plurality of temporary delimiter positions is determined as the standby time. For this reason, the standby time can be effectively reduced.

  In the present invention, in the determination process, the control unit multiplies a predetermined basic standby time, a coefficient related to the amount of liquid ejected for each area, and a coefficient related to the relative position of the recording medium. It is preferable to calculate the waiting time. Thereby, the individual standby time can be easily calculated.

  In the present invention, it is preferable that the coefficient related to the amount of liquid ejected for each region increases as the amount of liquid ejected for each region increases. Thereby, the individual standby time can be calculated with high accuracy.

  In the present invention, it is preferable that the coefficient related to the relative position of the recording medium is larger as the relative position of the recording medium is higher. Thereby, the individual standby time can be calculated with high accuracy.

  Further, in the present invention, the control means calculates the individual waiting time for each area by further multiplying a coefficient relating to the ease of curling for each area that occurs when the liquid is discharged in the determination process. It is preferable to do. Thereby, the individual standby time can be calculated with high accuracy.

  In the present invention, it is preferable that a plurality of the regions are defined from the center to the periphery of the recording medium, and the coefficient relating to the ease of curling for each region is larger as the region approaches the periphery of the recording medium. Thereby, the individual standby time can be calculated with higher accuracy.

  According to the liquid ejection apparatus of the present invention, even if the plurality of recording media related to the recording job is larger than the predetermined accommodation number of the holding mechanism, the plurality of recording media are divided into a plurality of groups equal to or less than the accommodation number, and the group is held in the holding mechanism. It becomes possible to convey every time. Then, when one or more recording media belonging to each group are placed on standby between the first surface and the second surface, even if curling occurs in the recording medium, the curling is restricted to an allowable height or less. Is possible. The provisional separation position that minimizes the completion time required to move the plurality of recording media to the receiving tray from the start of recording of the plurality of recording media related to the recording job is determined as the separation position. For this reason, it is possible to shorten the completion time while keeping the curl generated in the recording medium below the allowable curl height.

1 is a schematic side view showing the inside of an ink jet printer according to a first embodiment of the present invention. It is a fragmentary sectional view of the head contained in the printer shown in FIG. FIGS. 2A and 2B illustrate the receiving tray and the holding mechanism illustrated in FIG. 1, in which FIG. 1A is a situation diagram when the lower regulating member is in a support position, and FIG. It is. FIG. 2 is a block diagram illustrating an electrical configuration of the printer illustrated in FIG. 1. It is a flowchart which shows the control content which the control part of the printer shown in FIG. 1 performs. It is a flowchart which shows S2 shown in FIG. It is explanatory drawing for demonstrating the several area | region defined on a paper. (A) is a figure which shows an example of the individual waiting time for every sheet | seat in a 1st temporary separation position, (b) is the waiting time for every paper group in each temporary separation position, and the total waiting time in each temporary separation position. It is a figure which shows an example. It is a flowchart which shows the control content of the determination process which the control part of the printer which concerns on 2nd Embodiment of this invention performs. FIG. 10 is an explanatory diagram illustrating a situation in which provisional separation positions can be arranged on a plurality of sheets P. It is a flowchart which shows the control content of the determination process which the control part of the printer which concerns on 3rd Embodiment of this invention performs.

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

  First, with reference to FIG. 1 etc., the whole structure of the inkjet printer 1 which concerns on 1st Embodiment of this invention is demonstrated.

  As shown in FIG. 1, the printer 1 includes a housing 1a, an ink discharge head 2, a platen 5, a transport unit 20, a storage tray 3, a receiving tray 4, a holding mechanism 30, a moving mechanism 40 (see FIG. 3), two Paper sensors 6 and 7 and a control unit 100 are included. The ink discharge head 2 (hereinafter referred to as the head 2), the platen 5, the transport unit 20, the storage tray 3, the two paper sensors 6, 7, and the control unit 100 are disposed in the housing 1a. The receiving tray 4 is provided on the top plate of the housing 1a. Further, the holding mechanism 30 is disposed outside the housing 1 a and above the receiving tray 4. In other words, the receiving tray 4 is disposed below the holding mechanism 30.

  The head 2 is a line head having a substantially rectangular parallelepiped shape elongated in the main scanning direction. As shown in FIG. 2, the head 2 includes a flow path unit 12 and an actuator unit 17. The main scanning direction is parallel to the horizontal plane. The sub-scanning direction is a direction parallel to the horizontal plane and orthogonal to the main scanning direction. The vertical direction is a direction orthogonal to the sub-scanning direction and the main scanning direction. Further, in the transport direction of the paper P by the transport unit 20, the transport direction of the paper P under the head 2 is parallel to the sub-scanning direction and is a direction from left to right in FIG.

  The flow path unit 12 is a laminated body in which four plates 12a, 12b, 12c, and 12d are stacked. A flow path is formed inside, and a plurality of discharge ports 14a are opened on the lower surface. Black ink is ejected from the ejection port 14a of the head 2. The flow path formed inside the flow path unit 12 includes one manifold flow path 13 and a plurality of individual flow paths 14. The individual flow path 14 is provided for each discharge port 14 a and extends from the outlet of the manifold flow path 13 to the discharge port 14 a via the pressure chamber 16. The manifold channel 13 communicates with a tank (not shown) that stores ink. The ink supplied from the tank to the manifold channel 13 passes through the individual channel 14 and is ejected from the ejection port 14a.

  The actuator unit 17 is a laminated body in which a diaphragm 17a, a piezoelectric layer 17b, and a plurality of individual electrodes 17c are laminated. The diaphragm 17 a is fixed to the upper surface of the flow path unit 12 and closes the plurality of pressure chambers 16. The piezoelectric layer 17 b is fixed to the upper surface of the vibration plate 17 a and faces the plurality of pressure chambers 16. The plurality of individual electrodes 17 c are fixed to the upper surface of the piezoelectric layer 17 b and face each of the plurality of pressure chambers 16. The portion sandwiched between each individual electrode 17c and each pressure chamber 16 in the actuator unit 17 functions as an individual unimorph type actuator for each pressure chamber 16, and is independent according to the application of voltage to each individual electrode 17c. And can be deformed. By deforming the actuator so as to be convex toward the pressure chamber 16, the volume of the pressure chamber 16 is reduced, pressure is applied to the ink in the pressure chamber 16, and ink is ejected from the ejection port 14a. Thus, by selectively applying a voltage to the plurality of individual electrodes 17c, the head 2 can selectively eject ink from the plurality of ejection ports 14a.

  The platen 5 is disposed below the head 2 as shown in FIG. A predetermined gap suitable for recording is formed between the upper surface of the platen 5 and the ejection surface 2a which is the lower surface of the corresponding head 2.

  The transport unit (transport mechanism) 20 is configured to transport the paper P from the storage tray 3 to the holding mechanism 30 via the head 2 and the platen 5, and includes a paper feed roller 21 and a transport roller pair 22. -26 and guides 29a-29d.

  The paper feed roller 21 is disposed at a position in contact with the uppermost paper P in the storage tray 3. The paper feed roller 21 is rotated by driving a paper feed motor 21M (see FIG. 4) under the control of the control unit 100. As a result, the uppermost sheet P in the storage tray 3 is sent out from the storage tray 3. That is, the paper feed roller 21 is configured to transport the paper P stored in the storage tray 3 toward the transport roller pair 22.

  Each of the conveyance roller pairs 22 to 26 includes two rollers that are in contact with each other, and is configured to convey the paper P while being sandwiched between the two rollers. One of the two rollers constituting each of the conveyance roller pairs 22 to 26 is a drive roller, and rotates when the conveyance motor 20M (see FIG. 4) is driven under the control of the control unit 100. The other of the two rollers constituting each of the conveying roller pairs 22 to 26 is a driven roller that rotates in a direction opposite to the driving roller while contacting the driving roller as the driving roller rotates. Due to the rotation of the transport roller pairs 22 to 26, the paper P sent out from the storage tray 3 by the paper feed roller 21 is discharged from the outlet 1 b of the housing 1 a via the lower part of the head 2 and transported to the holding mechanism 30. .

  Each of the guides 29a to 29d is configured to demarcate the conveyance path of the paper P, and includes a pair of plates that are spaced apart from each other with a gap.

  The storage tray 3 is a box that opens upward, and can store a plurality of sheets P. In this embodiment, for example, A4 size plain paper is used. However, paper sizes other than A4 size may be used, and paper that causes curl when ejected ink permeates (coated paper or the like). Any paper may be used. The storage tray 3 can be attached to and detached from the housing 1a in the sub-scanning direction.

  The receiving tray 4 is configured to receive a plurality of sheets P that have been moved from the holding mechanism 30. As shown in FIG. 3, the receiving tray 4 is defined by a support surface 4a, a pair of side walls 4b, and one side wall 4c. The support surface 4a supports the lower surface of the paper P (the recording surface of the paper P on which an image is recorded by the head 2). The pair of side walls 4b are erected upward from both ends along the sub-scanning direction of the support surface 4a. The side wall 4c is erected upward from one end side along the main scanning direction of the support surface 4a (the end side on the upstream side in the transport direction of the paper P transported from the outlet 1b). An outlet 1b is formed above the side wall 4c. Thus, the receiving tray 4 is not defined by the side wall in the predetermined transport direction of the paper P transported from the outlet 1b, and the received paper P can be easily taken out by the user.

  The holding mechanism 30 and the moving mechanism 40 will be described below with reference to FIGS. 1 and 3. As shown in FIG. 1, the holding mechanism 30 is disposed at a position facing the outlet 1 b of the housing 1 a along the sub-scanning direction, and can accommodate the number of sheets P that can be received by the receiving tray 4. It is configured. In the present embodiment, the maximum accommodation number of sheets P of the holding mechanism 30 is, for example, 20 sheets. The holding mechanism 30 has a pair of regulating members 35. As shown in FIG. 3, the pair of regulating members 35 are arranged symmetrically with respect to a center line L extending in the vertical direction passing through the center of the support surface 4a in the main scanning direction.

  Each regulating member 35 includes an upper regulating member 31 and a lower regulating member 32. As shown in FIG. 3, the upper restricting member 31 has a flat plate-like horizontal portion 31a and a vertical portion 31b erected downward from the outer end portion in the main scanning direction of the horizontal portion 31a. It is formed into a shape. The lower surface 31a1 (second surface) of the horizontal portion 31a is formed longer than the sheet P along the sub-scanning direction, and the entire end portion along the sub-scanning direction of the sheet P conveyed to the holding mechanism 30. It is configured to be able to face each other. The vertical portion 31 b of the upper regulating member 31 is fixed to the side wall 4 b by a fixing portion 33. The lower regulating member 32 is composed of a flat plate similar to the horizontal portion 31a, and is disposed between the horizontal portion 31a and the support surface 4a in the vertical direction. Further, the lower regulating member 32 is rotatably supported at its outer end in the main scanning direction at the lower end of the vertical portion 31b, and is supported at the support position shown in FIG. 3A and the non-support shown in FIG. 3B. It is configured to be rotatable between positions.

  The support position is a position where the lower regulating member 32 is horizontally disposed, and the upper surface 32a (first surface) of the lower regulating member 32 and the lower surface 31a1 of the horizontal portion 31a face each other in the vertical direction. When the upper surface 32a of the lower regulating member 32 is at the support position, the paper P conveyed from the outlet 1b can be supported by the upper surface 32a. At this time, the upper surface 32a supports the lower surface of the paper P conveyed from the outlet 1b. When a plurality of sheets P are conveyed to the holding mechanism 30, the lower surface of the sheet P positioned at the lowest position among the plurality of sheets P is supported. On the other hand, the upper surface 31a1 of the horizontal portion 31a faces the upper surface of the uppermost sheet P among the plurality of sheets P.

  The lower surface 31a1 of the horizontal portion 31a and the upper surface 32a of the lower restricting member 32 can restrict curl generated in one or a plurality of sheets P conveyed to the holding mechanism 30 to a curl allowable height or less at the support position. In this way, they are spaced apart in the vertical direction. That is, the vertical separation distance between the lower surface 31a1 of the horizontal portion 31a and the upper surface 32a of the lower regulating member 32 is equal to or less than the allowable height of the curl. The allowable curl height is a predetermined height and is a curl height that does not hinder the discharge of the next paper P even if the paper P is curled. The curl height is a distance from the lowest point of the paper P to the highest point. When the paper P on which the ink is ejected and the image is recorded is conveyed to the holding mechanism 30, the printing surface extends while the ink ejected onto the paper P penetrates the paper P, so that the peripheral edge of the paper P is formed. Curling occurs to lift upwards. A two-dot chain line in FIG. 3A indicates a case where curling occurs on a plurality of sheets P. At this time, even if the paper P is to be curled largely, the lower surface 31a1 of the horizontal portion 31a exists there (the lower surface 31a1 and the upper surface 32a are spaced apart so that the curl is less than the allowable height. Therefore, the curl of the paper P is restricted to an allowable height or less.

  The non-supporting position is a position where the lower regulating member 32 is arranged vertically and the upper surface 32a of the lower regulating member 32 and the lower surface 31a1 of the horizontal portion 31a are not opposed in the vertical direction. When the upper surface 32a of the lower regulating member 32 is in the non-supporting position, the upper surface 32a cannot support the lower surface of the paper P. That is, the lower regulating member 32 is arranged at the non-supporting position by the moving mechanism 40, so that the paper P supported by the holding mechanism 30 can be moved to the receiving tray 4. Further, the curling restriction on the paper P is released by disposing the lower restricting member 32 at the non-supporting position.

  The moving mechanism 40 has a pair of solenoids 41. The solenoid 41 is fixed to the side wall 4b so that the movable iron core 41a can enter and exit from the side wall 4b along the main scanning direction. Further, the solenoid 41 is arranged in the vicinity of the lower end of the vertical portion 31b with the movable iron core 41a below the upper restricting member 31 in the vertical direction. That is, the solenoid 41 is disposed at a position where the movable iron core 41a faces the lower regulating member 32 in the non-supporting position. In this configuration, when the pair of solenoids 41 are driven by the control of the control unit 100 and the movable iron core 41a is arranged at the protruding position (position shown in FIG. 3A) protruding from the side wall 4b, the movable iron core 41a The lower restricting member 32 is engaged, and the lower restricting member 32 is positioned at the support position. On the other hand, when the pair of solenoids 41 are driven by the control of the control unit 100 and the movable iron core 41a is disposed at the retreat position (position shown in FIG. 3B) where the movable iron core 41a retreats from the protruding position into the side wall 4b. The engagement between 41a and the lower restricting member 32 is released, and the lower restricting member 32 is positioned at the non-supporting position. Thus, the moving mechanism 40 can move the paper P from the holding mechanism 30 to the receiving tray 4 by moving the lower regulating member 32 from the support position to the non-support position. Further, the moving mechanism 40 can support the paper P by the holding mechanism 30 by positioning the lower regulating member 32 at the support position.

  The control unit 100 includes a CPU (Central Processing Unit) 100a, a ROM (Read Only Memory) 100b, a RAM (Random Access Memory: including a nonvolatile RAM) 100c, an ASIC (Application Specific Integrated Circuit), an I / O. F (Interface), I / O (Input / Output Port), etc. are included. The ROM 100b stores a program executed by the CPU 100a, various fixed data including data on coefficients Ca, Cb, and Cc described later. The RAM 100c temporarily stores data necessary for program execution. The ASIC performs rewriting and rearrangement of image data (for example, signal processing and image processing). The I / F performs data transmission / reception with an external device (for example, a PC connected to the printer 1). I / O inputs / outputs detection signals of various sensors.

  Then, the control content which the control part 100 performs is demonstrated with reference to FIGS. The control unit 100 repeatedly executes the routine shown in FIG. 5 while the printer 1 is powered on. In the present embodiment, a case will be described in which there are a plurality of recording sheets for recording an image on the paper P based on a recording job (data indicating a series of processes corresponding to a recording command for recording an image on the paper P).

  First, the control unit 100 determines whether or not a recording job including image data transmitted from an external device has been received (S1). When the recording job has not been received (S1: NO), the control unit 100 repeats the process of S1. When the recording job is received (S1: YES), the control unit 100 executes a determination process (S2). In the present embodiment, a case where a recording job is received when the number of recording sheets is 30 (that is, larger than the maximum accommodation number in the holding mechanism 30) will be described below.

  For S2, as shown in FIG. 6, the control unit 100 first derives and sets a delimiter selection range for the number of recording sheets P based on the current recording job (SF1). In SF1, the separation selection range is set under the condition that the number of recorded sheets is divided by the minimum number of divisions. The minimum number of separations here is determined by the maximum number of sheets stored in the holding mechanism 30 and the number of recording sheets P based on the recording job, and is the minimum number (specific number) of separation positions. In this case, since the number of sheets to be recorded is 30 and the maximum number of sheets that can be stored in the holding mechanism 30 is 20, the number of separation positions is one, and the interval between the 10th to 21st sheets of paper P to be recorded. Are set to the temporary delimiter positions. Each of the sheet groups configured by the temporary separation positions is equal to or less than the maximum accommodation number. In this way, the control unit 100 selects the separation that is in the range of the tenth to twentieth sheets of the paper P, and includes a plurality of temporary separation positions in which the number of sheets P belonging to the sheet group is less than or equal to the maximum accommodation number. Set the range for the break position.

  After SF1, the control unit 100 sets a temporary delimiter position in the delimiter selection range set in SF1 (SF2). That is, the temporary separation position is set in order of the first temporary separation position for the tenth sheet, the second temporary separation position for the eleventh sheet, and the eleventh temporary separation position for the twentyth sheet.

  After SF2, the control unit 100 sets the number of paper groups and the paper P belonging to the paper group according to each temporary separation position (SF3). In this embodiment, since the number of recordings is 30, the number of paper groups is 2 at any temporary separation position, and the first half paper group divided at the temporary separation position is the first paper group, and the latter half The sheet group becomes the second sheet group. That is, in the case of the first temporary separation position, the first sheet group is composed of the first to tenth sheets P, and the second sheet group is composed of the eleventh to thirty sheets P. In the case of the second temporary separation position, the first sheet group is composed of the first to eleventh sheets P, and the second sheet group is composed of the twelfth to thirty sheets P. Thus, the paper P belonging to the paper group is set at each temporary separation position. After SF3, the control unit 100 sets n = 1 (SF4). Here, n indicates the order of the paper group.

  After SF4, the control unit 100 calculates the individual standby time for each of the areas A1 to F5 for each paper P belonging to the nth paper group at each temporary separation position (SF5). That is, in SF5, the control unit 100 calculates the individual standby time by multiplying the basic standby time and the three coefficients Ca, Cb, and Cc for each of the plurality of areas A1 to F5 defined for each paper P. . Note that the basic standby time in this embodiment is set to 10 seconds. Further, the calculated individual standby time is a standby time necessary for suppressing curling in each of the areas A1 to F5.

  As shown in FIG. 7, the plurality of regions A1 to F5 are regions arranged along the main scanning direction (the width direction of the paper P) and the sub-scanning direction (the conveyance direction of the paper P). More specifically, in the plurality of regions A1 to F5, the width from one end to the other end of the paper P in the main scanning direction is equally divided into five, and the width from one end to the other end of the paper P in the sub scanning direction is six. This is an area obtained by equally dividing. And in order to specify each area | region A1-F5, the row symbol of A-F and the column number of 1-5 are provided. The plurality of regions A1 to F5 can be divided into three regions: an outer region R1, an inner region R2, and an intermediate region R3. The outer area R1 is composed of areas A1, A2, A3, A4, A5, B1, B5, C1, C5, D1, D5, E1, E5, F1, F2, F3, F4, and F5. An annular region. The inner area R2 includes areas C3 and D3, and is located on the innermost side (center) of the paper P. The intermediate region R3 includes regions B2, B3, B4, C2, C4, D2, D4, E2, E3, and E4, and is an annular region between the outer region R1 and the inner region R2.

  The coefficient Ca is a coefficient related to the relative position in the vertical direction of the sheet P in the sheet group when the plurality of sheets P belonging to the sheet group are moved to the receiving tray 4 after waiting by the holding mechanism 30. Table 1 shows. As shown in Table 1, the coefficient Ca is larger as the sheet position on the receiving tray 4 is higher. In the holding mechanism 30, the conveyed paper P is arranged in an overlapping manner from the bottom to the top. The plurality of sheets P stacked by the holding mechanism 30 are moved to the receiving tray 4 in this overlapping state. For this reason, in this embodiment, the positional relationship in the holding mechanism 30 for the paper P and the positional relationship in the receiving tray 4 are the same. Accordingly, the coefficient Ca related to the vertical relative position of the paper P in the paper group may be a coefficient related to the relative position of the paper P in the paper group in either the holding mechanism 30 or the receiving tray 4.

  In the present embodiment, the coefficient Ca relating to the paper P disposed at the uppermost position in the receiving tray 4 is set to 1, and the coefficient Ca relating to the paper P existing below the paper P is farther from the uppermost paper P. It is set to be smaller. The paper P is not arranged on the paper P arranged at the uppermost position in the receiving tray 4. That is, the uppermost sheet P needs to be held by the holding mechanism 30 so that the curl due to the ejected ink does not progress beyond the allowable curl height.

  On the other hand, there is one or more sheets P on the sheet P below the uppermost sheet P. For this reason, even if the curling is going to proceed when the underlying paper P is on the receiving tray 4, the curling of the curling itself is suppressed by its own weight. More specifically, in the case of the paper P in which the amount of ink to be ejected and the ejected area are the same, the lower paper P is more than the upper paper P due to the weight effect of the upper paper P due to its own weight. Even curl does not progress. That is, the curl height is reduced. For this reason, the time for the lower paper P to recover to the state before curling is shorter than that of the upper paper P. In other words, the time from the start of the curl to the time when the curl does not advance beyond the allowable curl height is shorter for the lower paper P than for the upper paper P. Such curling progress, that is, a reduction in the recovery time, occurs in both the holding mechanism 30 and the receiving tray 4, and considering these, the sheet P below the uppermost sheet P is considered. The coefficient Ca concerning is set. That is, in the holding mechanism 30, the time for the lower paper P to recover to the state before curling is shorter than that of the upper paper P due to the weight effect caused by the weight of the upper paper P. That is, the lower sheet P requires less waiting time than the upper sheet P. As a result, by taking into account the relative positions of the plurality of sheets P in the holding mechanism 30, the standby time of the plurality of sheets P can be effectively shortened. Further, in the receiving tray 4, even if the lower paper P is about to curl, the curling is suppressed by the weight effect caused by the weight of the upper paper P. That is, the lower sheet P requires less waiting time than the upper sheet P. As a result, by taking into account the relative positions of the plurality of sheets P in the receiving tray 4, the waiting time for the plurality of sheets P can be further effectively shortened. The curling progress is suppressed as the number of sheets P increases, and when the curling progress exceeds a certain number (five sheets in the present embodiment), the curling proceeds exceeding the allowable curling height in the receiving tray 4. Can be surely prevented. Therefore, the coefficient Ca is “0” for the paper P whose fifth position from the top in the receiving tray 4 is.

  The coefficient Ca of the present embodiment is set so that even if curl occurs on each sheet P moved from the holding mechanism 30 to the receiving tray 4, the curl does not advance beyond the allowable curl height. ing.

  The coefficient Cb is a coefficient related to the amount of ink ejected for each of the areas A1 to F5 defined on each sheet P, and is shown in Table 2 below. As shown in Table 2, the coefficient Cb increases as the amount of ink ejected for each of the regions A1 to F5 increases. This is because, in each of the areas A1 to F5, when the amount of ejected ink increases, the time for penetrating the paper P becomes longer, and the curling time becomes longer. In other words, in each of the areas A1 to F5, when the amount of ejected ink decreases, the time for penetrating the paper P is shortened, and the curling time is shortened. In the present embodiment, in each of the areas A1 to F5, the maximum ink amount that can be ejected is 100% (a state in which solid printing is performed in the area), and the coefficient Cb at this time is 1. The coefficient Cb is set to be smaller as the ink amount to be ejected decreases in order of 80%, 60%, 40%, 20%, and 0%. When the ink amount is 0%, curling does not occur in that region, so the coefficient Cb is also 0.

  The coefficient Cc is a coefficient related to the ease of curling for each of the areas A1 to F5 defined for each sheet P. In the present embodiment, the region belonging to the outer region R1 is set to 1, the region belonging to the inner region R2 is set to 0.2, and the region belonging to the intermediate region R3 is set to 0.5. The coefficient Cc increases as the distance from the center (inside) to the periphery (outside) of the paper P increases. This is because the degree of curling of the paper P becomes larger when the same amount of ink is ejected outside than inside. If the amount of ink ejected is the same, the curling time by the ink is the same, but the degree of curl increases as the ink ejection area approaches the periphery of the paper P. As described above, the outer region R1 of the paper P having a large influence on the curl degree is set to a larger value.

  In SF5, first, the control unit 100 calculates the individual standby time for each of the areas A1 to F5 for the paper P arranged at the uppermost position in the receiving tray 4 at each temporary separation position. For example, when the ink amount in the area A1 related to the first temporary separation position is 40%, (10 seconds as the basic standby time) × (1 as the coefficient Ca) × (0.4 as the coefficient Cb) × (coefficient From 1) as Cc, 4 seconds, which is the individual standby time in the area A1, is calculated. Note that the amount of ink ejected in each of the areas A1 to F5 is derived by the control unit 100 referring to the image data of the recording job. The calculation is performed in the other regions A2 to F5 other than the region A1 similarly to the region A1. An example of the individual standby time (seconds) calculated in this way is shown in parentheses in each of the areas A1 to F5 in FIG. After calculating the individual standby times in all the areas A1 to F5 of the uppermost sheet P, the other sheets P belonging to the nth sheet group at the first temporary separation position are similarly described. The individual standby time for each of the areas A1 to F5 is calculated. At this time, the individual standby time for each of the areas A1 to F5 is calculated for all the sheets P belonging to the nth sheet group at the temporary separation position other than the first temporary separation position. All the individual standby times at the calculated temporary delimiter positions are stored in the RAM 100c. The calculation of the individual standby time in all the areas A1 to F5 of each sheet P belonging to the nth sheet group may be performed from any sheet P and any area A1 to F5.

  Next, the control unit 100 extracts the waiting time of the nth sheet group at each temporary separation position (SF6). Specifically, the control unit 100 first extracts the individual standby time for each sheet P belonging to the nth sheet group at each temporary separation position. That is, the maximum value among the individual standby times for the areas A1 to F5 of each paper P is extracted, and this is set as the individual standby time for each paper P at each temporary separation position. For example, as shown in FIG. 7, for the paper P arranged at the uppermost position in the receiving tray 4 at the first temporary separation position, 8 seconds is the maximum value, and this is the individual standby time of the paper P. Similarly, the individual standby time is extracted for the other sheets P. FIG. 8A shows an example of the individual standby time for each paper P belonging to the first paper group at the first temporary separation position at this time. It should be noted that since the coefficient Ca is 0 after the fifth sheet from the top of the sheet P, all the individual standby times are 0 seconds. Thereafter, the control unit 100 extracts the maximum individual standby time that is the maximum value of the individual standby time for each sheet P, and sets this as the standby time of the nth sheet group at the first temporary separation position. That is, the maximum individual standby time (for example, 8 seconds) among the individual standby times in FIG. 8A is the standby time of the nth sheet group (first sheet group) at the first temporary separation position. The standby time of the nth sheet group at other temporary separation positions other than the first temporary separation position is similarly extracted. Thus, since the standby time of the nth paper group is set to the maximum individual standby time among the individual standby times for each paper P, curling of the paper P constituting the nth paper group can be reliably suppressed. . As a modified example, the control unit 100 extracts the maximum individual standby time among the individual standby times for the areas A1 to F5 of all the sheets P belonging to the nth sheet group at each temporary separation position, and this is extracted as each temporary separation. The waiting time of the nth sheet group at the position may be used. By doing so, it is possible to save the trouble of extracting the individual standby time for each sheet P of the nth sheet group at each temporary separation position.

  Next, the control unit 100 links the standby time of the nth sheet group at each temporary separation position extracted in SF6 and the final page number of the nth sheet group and stores them in the RAM 100c (SF7). Thus, the standby time of the nth sheet group at each temporary separation position is set. FIG. 8B shows an example of the waiting time of the sheet group (here, the first sheet group) at each temporary separation position at this time.

  After SF7, the control unit 100 determines whether n in the nth sheet group at each temporary separation position is N (SF8). When N, which is the number of sheet groups set in SF3, is different from n of the nth sheet group (SF8: NO), the setting of the standby time of all the sheet groups at each temporary separation position is not completed. Therefore, the control unit 100 proceeds to SF9, adds 1 to n, and returns to SF5. In this way, the above-described processes SF5 to SF7 are repeated by the number of sheets. FIG. 8B also shows an example of the waiting time of the sheet group (here, the second sheet group) at each temporary separation position at this time. On the other hand, when n = N (SF8: YES), the setting of the standby time for each paper group at each temporary separation position is completed, and the process proceeds to SF10.

  In SF10, the control unit 100 calculates the total waiting time of the waiting time (maximum individual waiting time) of the first sheet group and the waiting time (maximum individual waiting time) of the second sheet group at each temporary separation position. That is, as shown in FIG. 8B, for example, the total standby time according to the first temporary separation position is 13 seconds, and the total standby time according to the second temporary separation position is 9 seconds. The total waiting time for the position is 13 seconds. In addition, it abbreviate | omits about the total waiting time concerning a 3rd temporary delimitation position-a 10th temporary delimitation position.

  After SF10, the control unit 100 extracts the minimum total standby time from all the total standby times calculated in SF10, and sets the temporary separation position related to the total standby time as the separation position (SF11). ). That is, for the current recording job, the second temporary separation position where the total waiting time is the minimum value is set as the separation position.

  Next, in accordance with the setting of the separation position of SF11, the control unit 100 uses the standby time of each paper group at the second temporary separation position stored in SF7 as the standby time of each paper group in the current recording job. Set (SF12). Based on the recording job, the completion time required from when the first sheet P on which an image is to be recorded is transported from the storage tray 3 until the last sheet P is moved to the receiving tray 4 is the number of separation positions (number of separation times). ) Is minimum, the smaller the total waiting time of the two sheet groups related to the separation position is, the smaller it is. For this reason, the completion time is reduced by setting the second temporary delimiter position related to the minimum total waiting time as the delimiter position. Thus, the determination process ends, and the process proceeds to S3.

  In S3, the control unit 100 controls each unit so as to execute a recording operation on one sheet P based on a recording job. That is, the control unit 100 controls the paper feed motor 21M and the transport motor 20M to transport the uppermost paper P in the storage tray 3, and further, based on the signal and image data from the paper sensor 6. The head 2 is controlled so that a predetermined amount of ink is ejected to the areas A1 to F5 of the paper P. Thereby, an image is recorded on the paper P. Thereafter, the control unit 100 controls the transport motor 20M to hold the paper P on which the image is recorded, the holding mechanism 30 (that is, the upper surface 32a of the lower restriction member 32 and the lower surface 31a1 of the horizontal part 31a of the upper restriction member 31). (S4).

  Next, the control unit 100 determines whether or not the paper P on which an image is recorded has been conveyed to the holding mechanism 30 based on the signal from the paper sensor 7 (S5). When the paper P is not conveyed to the holding mechanism 30 (NO), the process returns to S4, and when the paper P is conveyed to the holding mechanism 30, the process proceeds to S6.

  In S6, the control unit 100 determines whether or not the recording operation for all sheets P based on the recording job has been completed. If the recording operation has not been completed (NO), the process proceeds to S7. If the recording operation has been completed (YES), the process proceeds to S8. In S7, the control unit 100 determines whether or not it is the last page of the sheet group. If it is not the last page, the process returns to S3. If it is the last page, the process proceeds to S8. By returning to S3 and repeatedly executing the processes from S3 to S7, a plurality of sheets P are conveyed to the holding mechanism 30 for each group of sheets based on the separation position set in SF11 (conveying process). ).

  In S8, the control unit 100 refers to the standby time of the last page number corresponding to the paper P recorded immediately before as the current standby time from the standby time set in SF12. After S8, the control unit 100 determines whether or not the current standby time has elapsed since the last page of the sheet group was conveyed to the holding mechanism 30 (S9). If the current standby time has not elapsed (NO), the control unit 100 repeats the process of S9. When the current standby time has elapsed (YES), the control unit 100 moves the plurality of sheets P waiting on the holding mechanism 30 to the receiving tray 4 (movement process: S10). In S10, the control unit 100 controls the solenoid 41 to move the lower regulating member 32 from the support position to the non-support position. Thus, the plurality of sheets P waiting on the holding mechanism 30 are moved to the receiving tray 4. At this time, as indicated by a two-dot chain line in FIG. 3B, even when the plurality of sheets P are curled, the plurality of sheets P are separated from the lower surface 31 a 1 of the horizontal portion 31 a and the upper surface 32 a of the lower regulating member 32. The curl is regulated below the allowable height of the curl due to being supported in between. Furthermore, the curl does not advance beyond the allowable height of the curl. Then, as shown by the solid line in FIG. 3B, the plurality of sheets P are reduced in curl degree as time passes, and are restored to a state before the curl is generated.

  After S10, the control unit 100 determines whether or not the recording operation for all the sheets P based on the recording job has been completed, as in S6. When the recording operation is not completed (NO), the process proceeds to S3, and the recording operation is started in order for the paper P belonging to the next paper group. When the recording operation is finished (YES), a series of control flow is finished.

  As described above, according to the printer 1 according to the present embodiment, even if the number of recording sheets related to the recording job is larger than the maximum accommodation number of the holding mechanism 30, the plurality of sheets P are divided into a plurality of sheet groups equal to or less than the accommodation number. Thus, the sheet can be conveyed to the holding mechanism 30 for each sheet group. When the holding mechanism 30 waits for a plurality of sheets P belonging to the sheet group, even when the sheet P curls, the curl can be regulated to an allowable height or less. In the present embodiment, the separation positions of the plurality of sheets P are positions that can be separated by the minimum number of separation times, and the temporary separation positions at which the total waiting time of each sheet group at each temporary separation position is minimized. Is set. Of the completion time related to the recording job, a time other than the standby time for waiting each sheet group by the holding mechanism 30 (all the paper P related to the recording job is conveyed from the storage tray 3 to form an image on the paper P) The time for transporting the paper P to the holding mechanism 30 and the time for moving the paper P from the holding mechanism 30 to the receiving tray 4 for each paper group are the same at any separation position. For this reason, when the total waiting time of each sheet group is minimized, the completion time related to the recording job is minimized. For this reason, it is possible to shorten the completion time while keeping the curl generated in the paper P to be equal to or less than the allowable curl height.

  Also, by SF5 to SF11, the temporary delimiter position related to the minimum total wait time among all the total wait times is set as the delimiter position. This makes it possible to easily determine the break position.

  In SF12, the standby time of each paper group at the temporary separation position set as the separation position is set as the standby time of each paper group in the current recording job. Thereby, each individual standby time is calculated based on the amount of ink ejected for each of the areas A1 to F5, the relative position of the paper P in the receiving tray 4, and the like. By calculating the individual standby time at this time based on the relative position of the paper P, the curling is prevented from being suppressed by the weight of the upper paper P in both the holding mechanism 30 and the receiving tray 4. Be considered. In other words, the sheet group can be moved from the holding mechanism 30 to the receiving tray 4 when the curl does not advance beyond the allowable height. Since the curling recovery time can be shortened in the holding mechanism 30, the timing for moving the sheet group to the receiving tray 4 can be advanced. For this reason, the said individual waiting time can be shortened effectively. The maximum individual standby time among the plurality of individual standby times is extracted for each group, and the total standby time of these maximum individual standby times is calculated. Then, each of the maximum individual standby times for each group related to the minimum value among the plurality of total standby times calculated for the plurality of temporary delimiter positions is determined as the standby time. For this reason, the waiting time in the holding mechanism 30 can be effectively reduced.

  In SF5, the control unit 100 calculates the individual standby time by multiplying the basic standby time and the three coefficients Ca, Cb, and Cc for each of the plurality of areas A1 to F5 defined for each paper P. . Thus, the individual standby time can be easily calculated by multiplying the predetermined basic standby time by the coefficients Ca, Cb, and Cc. Since the individual standby time is calculated by multiplying the coefficient Cc in this way, the individual standby time can be calculated with high accuracy. The coefficient Cb increases as the amount of ink ejected for each of the regions A1 to F5 increases. The coefficient Ca increases as the relative position of the paper P increases. The coefficient Cc increases as the paper P approaches the periphery. . For this reason, the individual standby time can be calculated with high accuracy.

  As a modification, the individual standby time of each of the plurality of areas A1 to F5 defined for each sheet P may be calculated by multiplying the basic standby time and the two coefficients Ca and Cb. The plurality of individual standby times calculated in this way are extracted as the standby time through the processing of SF6. In this way, a temporary break position corresponding to the individual standby time extracted as the wait time is set as the break position. In these cases, the same effect as described above can be obtained. As another modification, a plurality of areas may not be defined for each sheet P, and only one area may be defined. In this case, one surface of the paper P becomes the one region, and the individual standby time of each paper P may be calculated by multiplying the basic standby time and the two coefficients Ca and Cb. The coefficient Cb at this time is a coefficient related to the amount of ink ejected to the entire sheet P, that is, the one region.

  Next, a printer according to a second embodiment of the present invention will be described below with reference to FIG. In the printer 1 according to the first embodiment described above, in the determination process, the number of recorded sheets is divided so that the number of separation positions is the minimum number. However, in the printer according to the present embodiment, the number of separation positions is the minimum number (specified The first completion time when the number of recorded sheets is divided to be equal to (number), and the second completion when the number of recorded sheets is divided so that the number of separation positions is a minimum number plus one (specific number). Compare with the time and adopt and set the break position with the smaller completion time. At this time, the waiting time of the sheet group corresponding to the separation position is also set. Note that the specific number may be not less than the minimum number of separation positions and not more than a predetermined number that is not less than the minimum number. The predetermined number here is preferably set to such an extent that there are not too many patterns of delimiter positions when calculating the second completion time. In the present embodiment, the predetermined number is 2, but it may be 5 or less. Since the processing other than the determination processing is the same as that of the first embodiment, the determination processing will be mainly described below. In the present embodiment, a case where a recording job when the number of recording sheets is 40 is received will be described below.

  In the determination process, the control unit 100 first calculates the first completion time on the condition that the number of recorded sheets is divided so that the number of separation positions is the minimum number (SG1). In SG1, processing substantially similar to SF1 to SF10 of the first embodiment is executed. In the present embodiment, since the number of recorded sheets is 40, the separation selection range is only the 20th sheet of paper P to be recorded. That is, the number of break positions is 1. For this reason, the position is set as a temporary separation position, and the first sheet group (first sheet to twentieth sheet P) and the second sheet group (21st sheet to 40th sheet P) are set. The Then, the standby time of each paper group is extracted in the same manner as in the first embodiment, and stored in association with the final number of pages of the corresponding paper group. Thereafter, the control unit 100 calculates a first total standby time. In the present embodiment, for example, the standby time of the first paper group is 8 seconds, the standby time of the second paper group is 6 seconds, and the first total standby time is 14 seconds. If the number of recorded sheets is not the same as an integer multiple of the maximum number of sheets stored in the holding mechanism 30, for example, 30 sheets, the same processing as SF1 to SF10 of the first embodiment is executed, and the first total standby is performed. Time is calculated.

  After the processing of SF1 to SF10 similar to that in the first embodiment is performed in this way, in SG1, the control unit 100 adds the transport time, the first total standby time that is the minimum value, and the movement time. Thus, the first completion time is calculated. The conveyance time is a time for conveying all the sheets P related to the recording job from the storage tray 3 to form an image on the sheet P and conveying the sheet P to the holding mechanism 30. The movement time is calculated by multiplying the operation time for operating the movement mechanism 40 to move one paper group from the holding mechanism 30 to the receiving tray 4 and the number of movements (number of paper groups).

  Next, the control unit 100 calculates the second completion time on the condition that the number of recorded sheets is divided so that the number of separation positions becomes a specific number (SG2). In SG2, first, a delimiter selection range is set. In the present embodiment, since the number of delimiter positions is 2, as shown in FIG. 10, there are a total of 209 delimiter position patterns. In FIG. 10, the first provisional separation position is “tentative 1”, the second provisional separation position is “temporary 2”, and the provisional separation positions of the first sheet P to the 39th sheet P are shown. The possible arrangement status of is shown. As shown in FIG. 10, when the first temporary separation position is arranged in order from the first sheet P to the 19th sheet P, the second temporary separation position is the 20th sheet P-39. In the first paper P, the pattern increases by one as the first temporary separation position approaches the 19th paper P. That is, when the first temporary delimiter position is on the first sheet P, the second temporary delimiter position can be arranged on either the 20th sheet or the 21st sheet P, and there are two patterns. It becomes. Then, as the first provisional separation position approaches the 19th sheet P one by one, the pattern of the second provisional separation position increases by one, and the first provisional separation position becomes the 19th sheet. When it is in P, the second temporary separation position can be arranged on any of the 20th to 39th sheets of paper P, and there are 20 patterns. As a result, there are 209 patterns for all the first and second temporary delimiter positions.

  In all these 209 patterns, the standby time for each sheet group in each pattern is calculated, and the second total standby time for each pattern is calculated. These second total standby times are also calculated by the same processing as the processing from SF5 to SF10 of the first embodiment. Thereafter, similarly to SG1, the control unit 100 calculates the second completion time by adding the transport time, the minimum second total waiting time, and the movement time. In the calculation of the second completion time, the time when the condition is different from that of SG1 is the second total waiting time and the movement time. The movement time increases as the number of movements increases by one.

  Thus, in SG3, the smaller completion time is extracted from the first completion time calculated in SG1 and the second completion time calculated in SG2. Then, the temporary delimiter position corresponding to the total waiting time adopted for the calculation of the extracted completion time is set as the delimiter position. The standby time of each paper group at the temporary separation position at this time is set as the standby time of each paper group in the current recording job.

  By setting the separation position and the waiting time in the determination process in this way, when the processes of S3 to S11 similar to those in the first embodiment described above are performed, the holding mechanism 30 sets them for each sheet group. The waiting time is waited and moved to the receiving tray 4. Thus, a series of control flows is completed.

  According to the printer according to the second embodiment, the first completion time is compared with the second completion time, and the separation position and the waiting time for each paper group are set so that the smaller completion time is adopted. Is set. For this reason, the completion time related to the recording job is minimized, and the completion time can be shortened while the degree of curling occurring on the paper P is set to a predetermined amount or less. Note that the same effect can be obtained with the same configuration as in the first embodiment.

  In the first and second embodiments described above, the paper P belonging to the paper group moved from the holding mechanism 30 to the receiving tray 4 may be curled below the allowable curl height. The sheet group may be moved from the holding mechanism 30 to the receiving tray 4 after being restored to the state before the occurrence. In this case, this can be realized by changing the coefficient Ca relating to the relative position of the paper P in the paper group. The individual standby time in this modified example is calculated by the same method as in the above embodiment except that the coefficient Ca1 is different from that in the above embodiment. The coefficient Ca1 in this modification is a coefficient related to the relative position in the vertical direction of the paper P in the paper group in the holding mechanism 30, and is shown in Table 3 below. Also in this modification, as shown in Table 3, the coefficient Ca1 is larger as the sheet position is higher.

  In this modification, the coefficient Ca1 is set considering that the curl has been restored when the holding mechanism 30 is moved to the receiving tray 4. Accordingly, the value of the coefficient Ca1 at each paper position is larger than in the above-described embodiment. The individual standby time is increased by this increase, and the standby time in the holding mechanism 30 is also increased. Also in this modified example, when the individual standby time is calculated based on the relative position of the paper P, it is considered that the holding mechanism 30 suppresses the curl progression due to the weight of the paper P above. . For this reason, it is considered that the curling recovery time in the holding mechanism 30 is shortened, and the timing for moving the sheet group to the receiving tray 4 can be advanced. Therefore, the individual standby time can be effectively shortened. In the present modification, it is not considered that the curling progress is suppressed by the weight of the upper sheet P in the receiving tray 4. Therefore, the holding mechanism 30 needs to wait for the paper P until the curl is recovered. Thereby, similarly to the above-mentioned embodiment, the waiting time in the holding mechanism 30 can be effectively reduced. As a result, it is possible to shorten the completion time while keeping the curl generated on the paper P to be equal to or less than the allowable curl height. In addition, since the paper P moved to the receiving tray 4 is not curled, it is possible to provide the user with the paper P with no curling.

  Next, a printer according to a third embodiment of the invention will be described below with reference to FIG. The printer according to the present embodiment is a condition in which the number of separation positions is the minimum number (specific number) as in the first embodiment in the determination process. When the printer is moved from the holding mechanism 30 to the receiving tray 4, the receiving tray 4, the temporary separation position at which the amount of ink ejected onto the paper P arranged at the uppermost position is the smallest is determined as the separation position. At this time, the waiting time of the sheet group corresponding to the separation position is also set. In the present embodiment, since the process other than the determination process is the same as that of the first embodiment, the determination process will be mainly described below. In the present embodiment, a case where a recording job when the number of recording sheets is 30 will be described below.

  In the determination process, the control unit 100 first sets a delimiter selection range on the condition that the number of recorded sheets is delimited so that the number of delimiter positions is the minimum number (SH1). Also in the present embodiment, as in the first embodiment, the number of recording sheets is 30, and the maximum number of sheets that can be stored in the holding mechanism 30 is 20. Therefore, the 10th to 21st sheets of paper P to be recorded Temporary break positions are set between P. Each of the sheet groups configured by the temporary separation positions is equal to or less than the maximum accommodation number. In this way, the control unit 100 selects the separation that is in the range of the tenth to twentieth sheets of the paper P, and includes a plurality of temporary separation positions in which the number of sheets P belonging to the sheet group is less than or equal to the maximum accommodation number. Set the range for the break position.

  After SH1, the control unit 100 derives the amount of ink ejected on the entire sheet P for each sheet P in the separation selection range (SH2). Here, each sheet P in the separation selection range corresponds to the last page of the first half sheet group separated at each temporary separation position, and is the most in the holding mechanism 30 and the receiving tray 4 among the sheets P belonging to the sheet group. This is a sheet P disposed above. The amount of ink ejected on the entire paper P is derived by the control unit 100 referring to the image data of the recording job. More specifically, the ink amount for each region A1 to F5 of the paper P is derived from the image data recorded on each paper P, and the ink amount for each paper P is derived by adding these ink amounts.

  After SH2, the control unit 100 determines the provisional separation position corresponding to the paper P corresponding to the smallest ink amount from among the ink amounts derived in SH2, as the separation position, and sets the paper group corresponding to the separation position. A number is set (SH3). That is, among the plurality of temporary separation positions within the separation selection range, the temporary separation position where the amount of ink ejected onto the uppermost sheet P in the holding mechanism 30 and the receiving tray 4 is the smallest is determined as the separation position. Is done. In this embodiment, since the number of recordings is 30, the number of paper groups is 2, the first half paper group separated at the separation position is the first paper group, and the second half paper group is the second paper group. Become. In the present embodiment, the last page in each paper group is arranged at the uppermost position when each paper group moves from the holding mechanism 30 to the receiving tray 4.

  After SH3, the control unit 100 multiplies the basic standby time and the coefficient Cb1 related to the last page of each paper group to calculate the standby time for each paper group (SH4). Note that the basic standby time in the present embodiment is set to 10 seconds as in the first embodiment.

  The coefficient Cb1 is a coefficient related to the amount of ink ejected on the paper P and is shown in Table 4 below. As shown in Table 4, the coefficient Cb1 increases as the amount of ejected ink increases. This is because when the amount of ink ejected on the paper P increases, the time for the ink to permeate the paper P becomes longer and the curling time becomes longer. In other words, when the amount of ink ejected on the paper P is reduced, the time for penetrating the paper P is shortened and the curling time is shortened. The amount of ink increases as the area where ink is ejected onto the paper P increases, and decreases as the area decreases. In the present embodiment, the maximum amount of ink that can be discharged onto the paper P is 100% (a state where solid printing is performed on the entire paper P), and the coefficient Cb1 at this time is 1. The coefficient Cb1 is set to be smaller as the amount of ink to be ejected (that is, the region where ink is ejected) decreases in order of 80%, 60%, 40%, 20%, and 0%. . When the ink amount is 0%, curling does not occur on the paper P, and the coefficient Cb1 is also 0.

  After SH4, the control unit 100 links the standby time of each sheet group at the separation position calculated in SH4 and the final page number of each sheet group and stores them in the RAM 100c (SH5). Thus, the waiting time for each sheet group is set.

  By setting the separation position and the standby time in the determination process in this way, each of the sheet groups is set for each sheet group when the processes of S3 to S11 similar to those in the first embodiment are performed. The holding mechanism 30 waits for the waiting time and moves to the receiving tray 4. Thus, a series of control flows is completed.

  According to the printer according to the third embodiment, when the sheet P with the smallest amount of ink ejected within the separation selection range becomes the separation position and the sheet group to which the sheet P belongs is moved to the receiving tray 4, The paper P related to the separation position is arranged at the uppermost position. The paper P is not arranged on the paper P arranged at the uppermost position in the receiving tray 4. That is, the uppermost sheet P needs to be held by the holding mechanism 30 so that the curl due to the ejected ink does not progress beyond the allowable curl height.

  In the present embodiment, the standby time calculated based on the amount of ink ejected onto the paper P at the separation position is the standby time of the paper group to which the paper P belongs. For this reason, in the holding mechanism 30, curling of the paper P related to the separation position can be suppressed to an allowable height or less. In the receiving tray 4, one or more sheets P exist on the sheet P that is lower than the sheet P that is the uppermost of the group of sheets. For this reason, even if the curling is going to proceed when the underlying paper P is on the receiving tray 4, the curling is suppressed by the weight of the paper P existing above. Thereby, it is possible to suppress curling of the entire sheet group in the receiving tray 4 as well. Further, the temporary separation position corresponding to the paper P with a small amount of ejected ink becomes the separation position, and the standby time of the paper group is calculated based on the ink amount, so the standby time is also reduced. Also in the present embodiment, as in the first embodiment, out of the completion time related to the recording job, the time other than the standby time for waiting each sheet group by the holding mechanism 30 (all the sheets P related to the recording job are The time for forming an image on the paper P by transporting from the storage tray 3 and transporting the paper P to the holding mechanism 30 and the time for moving the paper P from the holding mechanism 30 to the receiving tray 4 for each paper group) The same conditions apply at the break position. For this reason, when the waiting time of the sheet group is reduced, the completion time related to the recording job is minimized. For this reason, it is possible to shorten the completion time while keeping the curl generated in the paper P to be equal to or less than the allowable curl height.

  In SH1, since the number of break positions is a specific number, the process of deriving the break position and the standby time is simplified, and the break position and the standby time can be easily determined.

  In SH <b> 1 to SH <b> 3, the number of separation positions is the minimum number (specific number), and among the plurality of temporary separation positions in the separation selection range, the uppermost sheet P among the plurality of sheets P in the receiving tray 4. The temporary separation position at which the amount of ink ejected at the minimum is determined as the separation position. Thereby, a delimiter position can be determined easily. Further, since the specific number is the minimum number, the process of deriving the break position is simplified, and the break position can be easily determined.

  In SH4, the standby time in each paper group is calculated by multiplying the basic standby time by the coefficient Cb1 relating to the last page of each paper group. The last page in each paper group is arranged at the uppermost position when each paper group moves to the receiving tray 4. As a result, the standby time is determined based on the amount of ink ejected to the uppermost sheet P among the plurality of sheets P in the receiving tray 4. For this reason, the waiting time in the holding mechanism 30 can be effectively reduced. Further, the coefficient Cb1 increases as the amount of ejected ink increases. For this reason, the standby time can be calculated with high accuracy.

  As a modification, for each paper P in the separation selection range, the ink amount for each of the regions A1 to F5 is calculated by multiplying the ink amount for each of the regions A1 to F5 in the first embodiment by the coefficient Cc related to the region A1 to F5. The maximum value of these ink amounts may be used as the ink amount for the paper P. In this case, the paper P corresponding to the smallest ink amount among the ink amounts of each paper P in the calculated separation selection range is determined as the separation position. Then, when calculating the standby time, the control unit 100 may calculate the standby time in each paper group by multiplying the basic standby time and the coefficients Cb and Cc related to the last page of each paper group. Also in such a modification, the same effect as the above-described third embodiment can be obtained. In addition, since the standby time is calculated by further multiplying the coefficient Cc for each of the areas A1 to F5, the standby time can be calculated with high accuracy.

  As a modification in each of the above-described embodiments, the moving mechanism may move the pair of regulating members 35 that hold a plurality of sheets to the outside in the main scanning direction, or the pair of regulating members 35 that hold a plurality of sheets. You may rotate so that the inner side edge part regarding a main scanning direction may be arrange | positioned below an outer side edge part. In these cases as well, a plurality of sheets P can be moved from the holding mechanism 30 to the receiving tray 4.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, in the first and second embodiments described above and the modifications thereof, the individual standby time is calculated for all the sheets P belonging to the nth sheet group in SF5. The individual standby time for each region may be calculated for two or more sheets P including the sheet P arranged at the uppermost position in 30. In addition, in the region where the coefficients Ca and Cb are multiplied by 0, it is not particularly necessary to calculate the individual standby time.

  Further, the holding mechanism may have only one of the pair of regulating members 35. In this case, the restricting member preferably has a horizontal portion 31 a and a lower restricting member 32 that are longer than the width of the paper P in the main scanning direction. In addition, the holding mechanism may be configured by a member corresponding to the horizontal portion 31 a and two flat plates corresponding to the lower restriction member 32. In short, the holding mechanism faces the first surface facing the thickness direction of the paper P and can support the paper P, and faces the second surface opposite to the first surface of the paper P. What is necessary is just to have the 1st surface and the 2nd surface arrange | positioned at a predetermined distance. In this case, the moving mechanism only needs to be able to move at least the first surface so that the first surface takes a support position where the paper P is supported and a non-support position where the paper P is not supported.

  In addition, the present invention can be applied to both a line type and a serial type, and is not limited to a printer, and can be applied to a facsimile, a copier, and the like. Furthermore, the present invention can be applied to a liquid ejecting apparatus other than a printer that ejects liquid other than ink from nozzles.

2 Ink ejection head (liquid ejection head)
4 Receiving tray 4a Support surface 20 Transport unit (transport mechanism)
30 Holding mechanism 31a Horizontal portion (second member)
32 Lower regulating member (first member)
40 moving mechanism 100 control unit (control means)

Claims (13)

A liquid discharge head for discharging liquid;
A transport mechanism for transporting a recording medium on which an image is recorded by the liquid discharge head;
A second surface that can store a predetermined number or less of recording media and that is spaced apart from the first surface by a predetermined distance that is a distance equal to or less than an allowable height of curl in the vertical direction from the first surface. A holding mechanism for holding a plurality of recording media conveyed by the conveyance mechanism between the first surface and the second surface;
At least the first surface is moved so that the first surface takes a supporting position for supporting the plurality of recording media and a non-supporting position for the first surface not supporting the plurality of recording media. A moving mechanism;
The receiving tray is disposed below the holding mechanism and receives a plurality of recording media stacked in a vertical direction, and has a support surface that supports a lower surface of the lowest recording medium among the plurality of recording media. A receiving tray,
A control means for controlling the liquid ejection head, the transport mechanism, and the moving mechanism;
The control means includes
One or more separation positions where a plurality of recording media related to a recording job, which is a series of processes corresponding to a recording command, are divided into a plurality of groups each composed of a predetermined number of recording media or less, and standby at each separation position A determination process for determining time based on at least the amount of liquid ejected to each of the plurality of recording media;
In a state where the first surface takes the support position, the plurality of recording media are divided at one or more separation positions determined by the determination process, and the first surface and the second surface are group-by-group. A transport process for transporting between
After waiting one or more recording media belonging to the group located between the first surface and the second surface for the waiting time, the first surface is moved from the support position to the non-support position. And move process to move to
In the determination process, a delimiter selection range composed of a plurality of temporary delimitation positions for setting the number of recording media belonging to each group to be equal to or less than the predetermined accommodation number is set for each delimitation position, and the delimitation selection range Among the plurality of temporary delimiter positions, the temporary delimiter in which the completion time required from the start of recording of the plurality of recording media related to the recording job to the end of moving the plurality of recording media to the receiving tray is minimized. A liquid ejection apparatus, wherein a position is determined as the separation position.   In the determination process, the control means determines the separation position and the waiting time at each separation position under a condition that the number of the separation positions is a specific number that is greater than or equal to a minimum number and less than or equal to the predetermined number. The liquid ejection device according to claim 1, wherein the liquid ejection device is determined.   The control means, in the determination process, on the condition that the number of the break position is a specific number that is greater than or equal to the minimum number and less than or equal to the predetermined number, among the plurality of temporary break positions within the break selection range, 2. The liquid ejection according to claim 1, wherein a temporary separation position at which the amount of liquid ejected onto the uppermost recording medium when received by the receiving tray is minimized is determined as the separation position. apparatus.   The liquid ejecting apparatus according to claim 2, wherein the specific number is the minimum number.   4. The control unit according to claim 3, wherein, in the determination process, the waiting time is determined based on the amount of the liquid ejected to the uppermost recording medium when received by the receiving tray. Or the liquid discharge apparatus of 4.   The liquid ejection apparatus according to claim 5, wherein the standby time increases as the amount of the liquid ejected onto the recording medium increases.   The control means, in the determination process, the plurality of temporary delimiter positions in the delimiter selection range under a condition that the number of the delimiter positions is a specific number that is greater than or equal to the minimum number and less than or equal to the predetermined number. For each of the above, the amount of liquid ejected for each area in one or a plurality of areas defined for each recording medium, and the recording medium in the plurality of recording media in any of the holding mechanism and the receiving tray For each of the areas of two or more recording media including the uppermost recording medium of the plurality of recording media conveyed between the first surface and the second surface based on the relative position Calculating an individual standby time, extracting a maximum individual standby time which is a maximum value of the plurality of individual standby times for each group, calculating a total standby time of the maximum individual standby times, and Liquid ejecting apparatus according to the provisional delimiting position of the minimum value of the plurality of the total wait times are calculated for the temporary break position to claim 1, characterized in that determining the break position.   The control means determines, in the determination process, each of the maximum individual standby times for each of the groups related to the minimum value among the plurality of total standby times calculated for the plurality of temporary delimiter positions as the standby time. The liquid ejection device according to claim 7, wherein the liquid ejection device is a liquid ejection device.   In the determination process, the control means calculates the individual standby time by multiplying a predetermined basic standby time, a coefficient related to the amount of liquid ejected for each region, and a coefficient related to the relative position of the recording medium. The liquid ejection apparatus according to claim 7 or 8, wherein   The liquid ejection apparatus according to claim 9, wherein a coefficient relating to the amount of liquid ejected for each region increases as the amount of liquid ejected for each region increases.   11. The liquid ejection apparatus according to claim 9, wherein a coefficient related to the relative position of the recording medium is larger as the relative position of the recording medium is higher.   The control means calculates the individual standby time for each region by further multiplying a coefficient relating to the ease of curling for each region caused by the ejection of liquid in the determination process. The liquid ejection apparatus according to claim 9. A plurality of the regions are defined from the center to the periphery of the recording medium,
The liquid ejecting apparatus according to claim 12, wherein a coefficient relating to the ease of curling for each region increases as the area approaches the periphery of the recording medium.