JP2012020517A - Printing device, and method of controlling preparation operation in the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing dvice, along with a method of controlling preparation operation, which can suppress deterioration of print throughput by securing printing capability performed during printing, or efficiently performing preparation operation for inspection.SOLUTION: A carriage 32, which stops at a finish position PTn at a full side after finishing this (N-time) pass, operates a paper feed waiting expected time Tw until moving of the next (N+1 time) pass starts. It is determined whether the paper feed waiting expected time Tw exceeds flashing requirement condition time Tfc being waiting time required for flashing. When Tw>Tfc is satisfied, the carriage 32 is immediately caused to start moving to a flashing position FP without waiting for the time Tfc. Meanwhile, when Tw>Tfc is not satisfied, the carriage is not caused to move to the flashing position FP before the time Tfc has passed. Further, the next (N+1 time) pass starts from the flashing position FP after the flashing has finished.

Description

  The present invention relates to a printing apparatus that performs a preparation operation for ensuring or inspecting the printing capability of a printing unit, and a preparation operation control method in the printing apparatus.

  For example, in Patent Document 1, a control unit that controls a printer (printing apparatus) moves a recording head (printing unit) to a position away from a recording medium and discharges ink from the recording head every predetermined time. A configuration for execution is disclosed. When the recording medium is discharged, the flushing operation is executed before the start of the discharging operation only when the predetermined time (flushing time) elapses during the discharging operation of discharging the recording medium by the operation of the conveyance motor. When the flushing time is not exceeded during the operation, only the discharge operation is performed.

  In this way, not only during the discharging operation, if a waiting time occurs until the carriage (printing means) having the print head for some reason during printing before starting the movement (scanning) with the next printing, the carriage The flashing is performed by moving to the flushing position. For example, when the paper feed amount is large and the standby time until the next movement starts exceeds a certain time, the carriage moves from the standby position to the flushing position and performs the flushing operation.

  Further, in Patent Document 2, when the printer recognizes that a certain time or more has elapsed since the specific event, the printer sends the print head (that is, the carriage having the print head) from the print area to the adjustment area. A configuration is disclosed in which the print head performs an ink droplet ejection test (dot missing test) using laser light in the adjustment region, and performs flushing at the flushing position on the return path to the print region. Thus, during printing, for the purpose of ensuring or inspecting the printing capability of the print head, preparatory operations such as a flushing operation to ensure printing capability (ink ejection capability) and a nozzle inspection to inspect for the presence of printing capability are performed. Is called.

  As described above, in the conventional printer, when a waiting time exceeding a predetermined time from a predetermined timing during printing on the carriage occurs due to a large paper feed amount of the printing medium, the carriage moves to the flushing position and the flushing is performed. I was supposed to do it. Since this predetermined timing is a timing at which time measurement is started, it is hereinafter referred to as a time measurement timing, and since the predetermined time is a time condition necessary for performing flushing, it is hereinafter referred to as a flushing necessary condition time.

Japanese Patent Laying-Open No. 2008-229856 (for example, paragraph [0029] of the specification, etc.) JP 2001-277543 A (for example, paragraph [0059] of the specification, etc.)

  By the way, as shown in FIG. 12, the carriage CR having the print head H is located on the side opposite to the home side in the main scanning direction X and the home side HP where the home position HP, which is a standby position during non-printing, is located. Printing is performed for each pass by repeating a plurality of scans (passes) in the main scanning direction X with the full side. As shown in FIG. 12, the carriage CR that has stopped after the current (Nth) printing (n) is on standby while the current (Nth) paper feeding operation is being performed, and the next (N + 1) th time. When it is time to start the next path, the movement of the next path is started. At this time, as shown in FIG. 12, when the paper feed length from the current printing (n) position to the next printing (n + 1) position is relatively long, the actual waiting time T of the carriage CR (elapsed time from the start of waiting). When the time (time) exceeds the flushing requirement time Tfc (T> Tfc), the carriage CR moves to the home-side flushing position FP (for example, the home position HP) and flushes the receptacle such as the cap.

  For example, as shown in FIG. 12, when the carriage CR is waiting on the full side, if the waiting time T exceeds the flushing requirement time Tfc (T> Tfc), the carriage CR moves to the home flushing position FP. To flush. When the flushing is finished, the carriage CR returns to the original full side again, starts moving from the start position of the next printing (n + 1) on the full side, and performs the next printing (n + 1).

  At this time, the carriage CR that has stopped on the full side after completing the Nth pass moves to the home side, performs flushing, and then returns to the original position again. The total required time Ttf from the timing is In time it looks like this: That is, the total required time Ttf includes the flushing necessary condition time Tfc, the carriage movement time Tfh required to move the carriage CR from the full standby position to the flushing position FP, the flushing operation time Tf required for the flushing operation, and the flushing position. This is expressed as the sum of the carriage movement time Thf required until the carriage CR returns from the FP to the original position on the full side (next printing (n + 1) start position) (Ttf = Tfc + Tfh + Tf + Thf). When the total required time Tt f exceeds the required paper feed time Tpf required for the current paper feed, the carriage CR has not returned to the original position on the full side even though the paper feed operation has been completed. The next print start time is delayed. This delay in the next printing start time has a problem of causing a reduction in printing throughput. In this way, when the waiting time exceeds the necessary flushing condition time Tfc (preparation operation necessary condition time), the carriage CR starts moving and performs flushing (preparation operation). Nevertheless, the carriage CR has not returned to the next print start position, which has caused a problem that the print throughput is reduced.

  The present invention has been made in view of the above problems, and the object thereof is to efficiently perform a preparatory operation for ensuring printing capability or performing inspection during printing, thereby suppressing a decrease in printing throughput. It is an object to provide a printing apparatus and a preparation operation control method in the printing apparatus.

  In order to achieve the above object, the present invention ensures an acquisition unit that acquires print data, a printing unit that performs printing based on print data with relative movement with respect to a print medium, and a printing capability of the printing unit. Alternatively, the preparation means used for the preparation operation for inspection and the waiting time until the printing means starts the next printing are predicted, and it is determined whether or not the waiting time is longer than the first set time. When the determination means determines that the standby time is longer than the first set time, it is set as a waiting time until the relative movement without printing to the preparation operation position where the preparation operation should be performed is started. Before the second set time elapses, the printing unit starts relative movement to the preparation operation position, and the preparation operation is performed after the relative movement, while the waiting time is And a control unit that does not start relative movement of the printing unit to the preparation operation position at least before the second set time elapses when it is determined that it is not longer than the set time of 1. Is the gist. Note that the relative movement direction accompanying printing of the printing unit and the relative movement direction for the preparation operation of the printing unit are not necessarily the same. For example, in the case of a serial printing apparatus in which printing is realized by movement of printing means, the directions are often the same. On the other hand, in the case of a line-type and page-type printing apparatus adopting a configuration in which the relative movement during printing is realized by transporting the print medium and the relative movement during preparation operation is realized by moving the printing unit, A configuration in which each direction is different may be employed. Of course, these configurations are merely examples, and the present invention is not limited thereto.

  According to this invention, when it is determined that the standby time (predicted standby time) until the next printing of the printing unit is started is longer than the first set time, the relative movement of the printing unit to the preparation operation position is started. The relative movement of the printing unit to the preparatory operation position is started before the second set time set as the waiting time until the time elapses. If it is determined that the standby time is not longer than the first set time, the relative movement of the printing unit to the preparation operation position is not started at least before the second set time has elapsed. Therefore, the preparatory operation during printing can be performed appropriately while minimizing the delay in printing.

  In the printing apparatus of the present invention, the control unit adjusts the start timing of the preparation operation to be performed after the relative movement of the printing unit to the preparation operation position in accordance with the start timing of the next printing.

  According to the present invention, since the start timing of the preparation operation performed after the relative movement of the printing unit to the preparation operation position is adjusted in accordance with the start timing of the next printing, even when the standby time is relatively long, The preparation operation is performed at a time relatively close to the start time of the next printing, and the next printing can be performed with a higher printing capability.

  In the printing apparatus according to the aspect of the invention, the control unit measures an actual standby time of the printing unit, and when the determination unit determines that the predicted standby time is not longer than the first set time. When the actual standby time exceeds the second set time, the relative movement of the printing unit to the preparation operation position is started.

  According to the present invention, even if the relative movement to the preparatory operation position of the printing unit is not started as a result of determining (predicting) that the standby time is not longer than the first set time, contrary to the prediction, When the waiting time exceeds the first set time, the preparatory operation can be performed.

  In the printing apparatus of the present invention, the first set time is substantially equal to the second set time. According to the present invention, when it is determined that the predicted standby time is longer than the second set time (= first set time) set as the waiting time until the relative movement to the preparation operation position starts, Before the second set time elapses, the relative movement of the printing means to the preparation operation position is started. If it is determined that the predicted standby time is not longer than the second set time (= first set time), at least before the second set time has elapsed, the relative movement of the printing unit to the preparation operation position is performed. Does not start. Therefore, the preparatory operation during printing can be performed appropriately while minimizing the delay in printing.

  In the printing apparatus according to the aspect of the invention, the waiting time predicted by the determination unit is the next time when the preparation unit performs the preparation operation by moving relative to the preparation operation position before the printing unit starts the next printing. This is a waiting time until printing is started, and the first set time is the maximum allowable waiting time during which the predicted waiting time can start the next printing without a delay in the start time of the next printing. It is.

  According to the present invention, the determination unit predicts a waiting time until the next printing is started when the printing unit performs a preparatory operation before starting the next printing. When it is determined that the predicted standby time (hereinafter referred to as “predicted standby time”) is longer than the maximum allowable standby time (first set time) that can be started without delay of the next printing start time. The relative movement of the printing unit to the preparation operation position is started before the second set time set as the waiting time until the relative movement of the printing unit to the preparation operation position starts. When it is determined that the predicted standby time is not longer than the first set time, the relative movement of the printing unit to the preparation operation position is not started at least before the second set time has elapsed. Therefore, it is possible to appropriately perform the preparatory operation during printing while minimizing the delay in printing.

  A plurality of types of the preparatory operations are prepared in accordance with the difference in the printing capability recovery capability or the inspection capability of the printing unit, and the control unit is responsive to the waiting time or the remaining printing amount of the plurality of types of the preparatory operations. One is selected, and the printing unit is caused to perform the selected one preparation operation.

  According to the present invention, the control unit selects one preparation operation corresponding to the standby time or the remaining printing amount, and causes the printing unit to perform the selected preparation operation. Accordingly, it is possible to appropriately perform the remaining printing by performing an appropriate preparation operation according to the standby time or the remaining printing amount.

  In the printing apparatus according to the aspect of the invention, the printing unit performs printing by performing a reciprocating motion relative to the printing medium, and the preparatory operation position is the first of both sides of the path on which the printing unit performs the reciprocating motion. And when the relative movement to the preparatory operation position is performed from the second side opposite to the first side in the path from the second side toward the first side. Further includes changing means for changing the print data so that the printing means can start the next printing from the first side after performing the preparation operation at the preparation operation position.

  According to the present invention, when the printing unit performs the relative movement for the preparatory operation from the second side to the first side in the path of the relative movement, the printing unit is moved to the first side by the changing unit. The print data is changed so that printing can be started from the first side after the preparation operation is performed. Therefore, even if the printing unit moves to the first side which is the opposite side of the path for the preparation operation, the printing unit starts relative movement with the next printing from the first side without returning to the second side. be able to. As a result, printing throughput can be improved.

  The present invention includes a printing unit that performs printing based on print data with a relative movement with respect to a print medium, and a printing unit that includes a preparation unit that is used for a preparation operation for securing or inspecting the printing capability of the printing unit. A preparatory operation control method in the apparatus for predicting a standby time until the next relative movement accompanied by printing by a printing unit is started, and determining whether the predicted standby time is longer than a first set time. And determining that the waiting time is longer than the first set time, a second set time set as a waiting time until the relative movement for the preparation operation starts is passed. Before, when the printing means starts relative movement for the preparatory operation, while it is determined that the standby time is not longer than the first set time, at least the second setting Before elapse between shall be summarized in that and a control procedure that does not initiate the relative movement for the preparation operation to the printing unit. According to this invention, it is possible to obtain the same effect as that of the invention relating to the printing apparatus.

(A) (b) The schematic perspective view of the printing apparatus in 1st Embodiment. FIG. 3 is a schematic plan view illustrating an ink ejecting unit. FIG. 3 is a schematic side view illustrating an ink ejecting unit and a transport device. FIG. 3 is a block diagram illustrating a main part of an electrical configuration of the printing apparatus. The block diagram which shows the principal part of the function structure of a computer. FIG. 6 is a schematic diagram for explaining a carriage operation during flushing. 6 is a timing chart showing a printing operation and a paper feeding operation. The graph explaining the pass operation at the time of bidirectional | two-way printing, and the change process at the time of flushing. 6 is a flowchart illustrating a printing process with flushing. 10 is a flowchart illustrating a printing process with flushing according to the second embodiment. The schematic diagram explaining the carriage operation | movement at the time of the flushing in a modification. The schematic diagram explaining the carriage operation | movement at the time of the flushing in a prior art.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
FIG. 1A is a perspective view showing an example of the configuration of the printing apparatus of the present embodiment, and FIG. 1B is a perspective view showing an example of the internal configuration of the main part of the printing apparatus. As shown in FIGS. 1A and 1B, a printing apparatus 11 is a serial type ink jet type that performs printing processing on roll-shaped printing paper (hereinafter also referred to as “roll paper P”) as an example of a printing medium. It is a printer. Such a printing apparatus 11 includes a printing apparatus main body 12 that performs a printing process on the roll paper P, and support legs 13 that support the printing apparatus main body 12 from below in the direction of gravity.

  Further, on the left side when viewed from the front side of the printing apparatus main body 12, there are a holder portion 15 that accommodates a plurality (six in this embodiment) of ink cartridges 14 and an openable / closable holder that covers the holder portion 15 from the front side. A cover 16 is provided. Each ink cartridge 14 stores inks (printing materials) of different types (for example, colors). An operation panel 17 that is operated by a user is provided on the upper right side when viewed from the front side of the printing apparatus main body 12, and the operation panel 17 includes a liquid crystal screen and various buttons.

  On the upper side of the printing apparatus main body 12, a medium accommodating portion 18 in which the roll paper P is accommodated is provided. The roll paper P accommodated in the medium accommodating portion 18 is wound around a shaft member 19 extending along the main scanning direction X. A shaft support portion 20 that supports the shaft member 19 in a rotatable state is provided on both sides of the medium accommodating portion 18 in the main scanning direction X, respectively. Then, when the shaft member 19 rotates in a predetermined rotation direction (direction indicated by an arrow in FIG. 3), the roll paper P is fed into the printing apparatus main body 12 as a long sheet. A removable cover 21 for covering the roll paper P stored in the medium storage unit 18 is provided on the front side of the medium storage unit 18.

  In the printing apparatus main body 12, an ink ejecting section 22 that ejects ink to a portion of the roll paper P that is transported into the printing apparatus main body 12, and a transport that transports the roll paper P toward the ink ejecting section 22. A conveying device 23 (see FIG. 3) is provided as an example of the means. Further, the printing apparatus main body 12 is provided with a paper discharge unit 24 that discharges a portion of the roll paper P to which ink has been attached by the ink ejecting unit 22, that is, a portion where printing has been completed. The printing apparatus main body 12 has an openable / closable main body cover 25 for covering the inside of the printing apparatus main body 12.

Next, the ink ejecting unit 22 will be described.
As shown in FIGS. 2 and 3, the ink ejecting section 22 includes a support member 30 that extends in the main scanning direction X (the left-right direction in FIG. 2). The support member 30 is positioned on the upstream side (medium storage unit 18 side) above the downstream side (paper discharge unit 24 side) in the sub-scanning direction (conveying direction) Y substantially orthogonal to the main scanning direction X. Is arranged. That is, the support member 30 has a support surface 30a that is inclined with respect to a horizontal plane. The support surface 30 a of the support member 30 supports a portion of the roll paper P that is conveyed into the printing apparatus main body 12.

  Further, the ink ejecting section 22 includes a guide shaft 31 extending in the main scanning direction X, and the guide shaft 31 is disposed to face the support surface 30 a of the support member 30. The guide shaft 31 supports the carriage 32 in a state in which the carriage 32 can reciprocate along the main scanning direction X.

  The ink ejection unit 22 includes a carriage motor (hereinafter also referred to as “CR motor”) 33 that can rotate in both forward and reverse directions, and a carriage drive unit that transmits a driving force output from the CR motor 33 to the carriage 32. 34. The carriage drive unit 34 includes a pair of pulleys 35 and 36 that are rotatably supported at both ends in the main scanning direction X on the rear surface of the printing apparatus main body 12. An output shaft (not shown) of the CR motor 33 is connected to the pulley 35 in a state where power can be transmitted. Further, between the pair of pulleys 35 and 36, an endless timing belt 37, a part of which is connected to the carriage 32, is hung. The carriage 32 moves while being guided by the guide shaft 31 along the main scanning direction X when the driving force from the CR motor 33 is transmitted via the carriage driving unit 34.

  Further, on the rear surface side of the carriage 32, a linear encoder 38 shown in FIG. 4 for detecting the position, the moving speed and the moving direction of the carriage 32 in the main scanning direction X is provided. As shown in FIG. 4, the linear encoder 38 includes a detection tape 39 extending in the main scanning direction X and a detection unit 40 supported by the carriage 32. The tape 39 to be detected is supported by the printing apparatus main body 12 in a non-movable state, and has a large number of slits 39a formed at equal intervals along the main scanning direction X. The detection unit 40 includes a plurality of (for example, two) sensors (not shown) arranged at different positions in the main scanning direction X. From each sensor of the detection unit 40, a pulse-like detection signal having a pulse number proportional to the moving distance of the carriage 32 and a pulse cycle inversely proportional to the moving speed of the carriage 32 is supplied to the control circuit 60 (see FIG. 4). Are output respectively.

  On the carriage 32, a plurality of (six in this embodiment) sub tanks (not shown) for temporarily storing various inks supplied from the respective ink cartridges 14 are provided. Each of these sub tanks is supplied with ink from an individually corresponding ink cartridge 14 by driving an ink supply device 41 (see FIG. 4).

  As shown in FIG. 2, a print head 42 is provided on the side of the carriage 32 that faces the support member 30. The print head 42 includes a plurality of nozzles 43 (only six are shown in FIG. 2) to which ink is supplied from a sub tank, and a plurality of drive elements (not shown) corresponding to the nozzles 43 (for example, piezoelectric elements). Is provided. Each nozzle 43 opens in a nozzle forming surface 44 that faces the support member 30 in the print head 42. Then, the ink supplied from the sub tank is ejected (supplied) from the nozzle 43 toward the support member 30 by driving of the drive element. Therefore, in this embodiment, the print head 42 and the carriage 32 constitute a printing unit that causes ink to adhere to the portion of the roll paper P that has been transported to the ink ejection unit 22.

  On one side (right side in FIG. 2) of the carriage 32 in the main scanning direction X, a home position HP that is a standby position of the carriage 32 during non-printing is set. In the present embodiment, of both sides of the path (main scanning path) where the carriage 32 is scanned, the home position HP side is the home side (one side), and the opposite side is the full side (the other side). Respectively. At the time of printing, the carriage 32 performs printing on the roll paper P by alternately performing the forward movement from the home side to the full side and the backward movement from the full side to the home side. As a printing method, a bidirectional printing method in which printing is performed in both directions of the forward and backward movements of the carriage 32, and printing is performed when only one direction of the carriage 32 is moved, and printing is not performed when the carriage 32 is moved in the other direction. A unidirectional printing method that runs idly (empty scanning) is employed. For example, the bidirectional printing mode is set in the draft printing mode in which the printing speed is given priority over the printing quality, and the unidirectional printing is set in the high-definition printing mode in which the printing quality is given priority over the printing speed.

  As shown in FIG. 2, a maintenance device 45 for performing various maintenance of the print head 42 is disposed immediately below the carriage 32 when it is at the home position HP. The maintenance device 45 is movable in a direction (vertical direction in FIG. 2) in which the nozzle 43 of the print head 42 located at the home position HP contacts and separates from a nozzle forming surface 44 (lower surface in FIG. 2). A bottomed substantially cylindrical cap 46 and an elevating mechanism 47 for moving the cap 46 up and down are provided. The cap 46 is capable of receiving ink ejected or sucked and discharged from each nozzle 43 of the print head 42 located at the home position HP (also referred to as “waste ink”).

  When the carriage 32 reciprocates in the main scanning direction X and ink droplets are ejected onto the roll paper P to perform printing of an image or the like during printing, when the flushing execution condition is satisfied, the carriage 32 moves to the home position HP and caps. Flushing is performed in which ink droplets that are not related to printing are ejected into 46 (that is, idle ejection).

  During printing in which the print head 42 is not capped, the ink in the nozzle 43 gradually increases in viscosity, and the nozzle 43 is clogged. In order to prevent this kind of nozzle clogging, in this embodiment, when the flushing execution condition is satisfied during printing, the carriage 32 is moved to the home position HP to perform flushing. There are two types of flushing execution conditions. One is when the time measured from the timing when the previous flushing is completed when the carriage 32 stops after one pass is over a certain time (flushing interval time Tfi). The second is a standby time (hereinafter referred to as “paper feed standby”) in which the roll paper P is expected to wait until the next pass starts from the timing when the carriage 32 stops after completing one pass. The predicted time Tw ”) is predicted to exceed the flushing requirement time Tfc (first set time). When one of these conditions is satisfied, the carriage 32 is moved to the home position HP to perform flushing. In this example, which is the serial type printing apparatus 11, the start of the next pass of the carriage 32 corresponds to the start of the next printing of the printing means.

  In the present embodiment, this flushing corresponds to a preparatory operation for ensuring the capability of the print head 42. The maintenance device 45 (particularly the cap 46 among them) used for this preparation operation corresponds to the preparation means. Further, in the present embodiment, the flushing necessary condition time Tfc is an example in which both the first set time and the second set time are used. However, even if the first set time and the second set time are made different. I do not care. In this example in which the carriage 32 performs flushing at the home position HP, the home position HP may be referred to as a flushing position FP.

  Further, the maintenance device 45 includes a nozzle inspection unit 48 shown in FIG. 2 that inspects the presence or absence of defective nozzles such as clogging among all the nozzles of the print head 42. In the present embodiment, the nozzle inspection is performed for a predetermined number of times (a value within a range of 1 to 10 times) with an ink droplet charged from the inspection target nozzle of the print head 42 (hereinafter also referred to as “charged ink droplet”) toward the cap 46. ) It is done by jetting. The nozzle inspection unit 48 detects the potential change on the cap 46 side in the process until the charged ink droplet ejected from the inspection target nozzle lands on the cap 46, and inspects whether there is a defective nozzle based on the detection result. Adopt the method. In this inspection method, if a potential change on the cap 46 side is detected, the inspection target nozzle is determined as a normal nozzle capable of ejecting ink droplets. On the other hand, if a potential change on the cap 46 side is not detected, the inspection target nozzle is It is determined that a defective nozzle cannot eject ink droplets.

  In the present embodiment, this nozzle inspection is performed only at the start of printing because the required time is relatively longer than the required time for flushing. However, it may be performed during printing as in the case of flushing. In this case, this nozzle inspection corresponds to a preparatory operation for inspecting the printing capability of the print head 42. And the nozzle test | inspection part 48 provided for this preparation operation | movement corresponds to a preparation means. Further, the first set time may be the same as the flushing necessary condition time Tfc at the time of flushing, and flushing and nozzle inspection may be performed together by one carriage movement as in Patent Document 2. Of course, the necessary condition time Tnc for nozzle inspection may be set individually.

  The maintenance device 45 includes a suction pump 49 (shown in FIG. 4) for cleaning. By driving the suction pump 49 in a state where the cap 46 is in contact with the nozzle forming surface 44 of the print head 42, the space surrounded by the cap 46 and the nozzle forming surface 44 is made negative pressure, and the negative pressure causes the nozzle 43. The nozzle 43 is cleaned by forcibly discharging the ink from the nozzle. For example, when a defective nozzle is detected by nozzle inspection, cleaning is performed. As described above, the maintenance device 45 is used for capping, flushing, nozzle inspection, cleaning, and the like.

  Next, the transport device 23 will be described. As shown in FIG. 3, the transport device 23 is a device that transports the roll paper P along the sub-scanning direction Y. Such a transport device 23 includes a pair of paper feed rollers 50 disposed on the upstream side of the support member 30 in the sub-scanning direction Y (in the upper right direction in FIG. 3 and on the medium accommodating unit 18 side), and in the sub-scanning direction Y. A discharge roller pair 51 is provided on the downstream side of the support member 30 (in FIG. 3, diagonally to the left and on the discharge unit 24 side). The pair of paper feed rollers 50 and the pair of paper discharge rollers 51 are driven rollers 50a and 51a that are rotated by a driving force transmitted from a paper feed motor (hereinafter referred to as “PF motor 52”), and rotations of the drive rollers 50a and 51a. And driven rollers 50b and 51b that are driven to rotate. Then, when the driving rollers 50a and 51a are rotated in the arrow direction shown in FIG. 3 by the driving force transmitted from the PF motor 52, the roll paper P sandwiched between the roller pairs 50 and 51 is sub-scanning direction Y. The paper is fed (conveyed) to the paper discharge unit 24 side. In addition, the roll paper P is sent out when the shaft member 19 rotates in a predetermined direction (the direction indicated by the arrow in FIG. 3) in the medium accommodating portion 18.

  Next, the electrical configuration of the printing apparatus 11 will be described with reference to FIG. As shown in FIG. 4, the control circuit 60 (controller) of the printing apparatus 11 is connected to the host apparatus HC via an interface 61 in a state where various information such as print job data D1 can be transmitted and received. In addition, operation information regarding the operation result of the operation panel 17 by the user is input to the interface 61 of the control circuit 60.

  The host device HC is provided with the printer driver PD shown in FIG. 4 for generating the print job data D1. The printer driver PD is constructed by a CPU (not shown) of the host device HC and a program. The print job data D1 includes a command and image data relating to an image to be printed on the roll paper P. The printer driver PD converts the resolution of the image data to the printing resolution of the printing apparatus 11, and performs color conversion processing on the converted image data. Subsequently, the printer driver PD performs halftone processing (gradation number conversion processing) on the image data that has been subjected to color conversion processing.

  Then, the printer driver PD outputs (transfers) print job data D1 including the image data subjected to the above-described various processes and a print control command to the printing apparatus 11 side. At this time, the print job data D1 is transferred for each scanning of the carriage 32 (for one pass). The print job data D1 for one pass is also referred to as a command for each main scan (one pass) and sub-scan (paper feed), and image data for one main scan (hereinafter also referred to as “divided image data D2”). ).

  Next, the control circuit 60 of the printing apparatus 11 will be described. The control circuit 60 includes a computer 62 (microcomputer) (a portion surrounded by a one-dot chain line in FIG. 4). The computer 62 includes a CPU 63, an ASIC 64 ((Application Specific IC)), a ROM 65, a non-volatile memory 66, and a RAM 67, which are connected to each other via a bus 68. The computer 62 is electrically connected to the drivers 69, 70, 71 and 72. The computer 62 controls the PF motor 52 via the PF driver 69 and also controls the CR motor 33 via the CR driver 70. The computer 62 controls the print head 42 (specifically, each drive element in the print head 42) via the head driver 71 and the ink supply device 41 via the ink supply driver 72. To control.

  Further, the computer 62 includes a conductor (for example, a metal mesh) (not shown) that conducts to an ink droplet receiving portion in the cap 46 that constitutes the nozzle inspection portion 48 via the nozzle inspection voltage application circuit 73, and the print head 42. It is electrically connected to a nozzle forming surface 44 (particularly a metal nozzle plate). At least during nozzle inspection, the computer 62 applies, for example, a positive potential to the conductor of the cap 46 via the nozzle inspection voltage application circuit 73 and also applies, for example, a negative potential to the nozzle forming surface 44. A detection signal indicating a potential change of the cap 46 when a negatively charged ink droplet is ejected from the inspection target nozzle of the print head 42 is input to the computer 62 via the detection circuit 74. Specifically, the detection circuit 74 includes an integration circuit that integrates the detection signal input from the conductor of the cap 46, an inverting amplification circuit that inverts and amplifies the signal output from the integration circuit, and the inverting amplification circuit. An A / D conversion circuit for converting the output analog signal into a digital signal is provided.

  The ROM 65 stores various control programs and various data. The nonvolatile memory 66 stores various programs including a firmware program and various data necessary for print processing. Specifically, the non-volatile memory 66 is used as a criterion for determining whether or not to perform flushing when a relatively long waiting time occurs until scanning of the next pass starts at the end of one pass of the carriage 32. A flushing time information storage unit 66a for storing the above-described flushing necessary condition time Tfc and the like.

  The RAM 67 temporarily stores program data executed by the CPU 63, various types of data that are calculation results and processing results by the CPU 63, various types of data processed by the ASIC 64, and the like. The RAM 67 includes a reception buffer 67a, an intermediate buffer 67b, and an output buffer 67c.

  Next, the computer 62 of this embodiment will be described. FIG. 5 is a block diagram showing a functional configuration of the computer 62. FIG. 5 mainly illustrates functional portions related to flushing control performed during printing on the roll paper P, and other functional portions such as nozzle inspection are not shown.

  As shown in FIG. 5, the computer 62 includes a print control unit 75, a flushing control unit 76, a job control unit 77, an image processing unit 78, and a transfer unit 79 as functional parts realized by at least one of hardware and software. And a sequence control unit 80. The print control unit 75 mainly controls print control, and includes a main control unit 81, a command analysis unit 82, a data analysis unit 83, a calculation unit 84, and a paper feed length acquisition unit 85. The flushing control unit 76 mainly controls flushing control, and includes a calculation unit 86, a first determination unit 87, a second determination unit 88, a third determination unit 89, and a timer 90 therein. The print control unit 75 and the flushing control unit 76 output various instructions of the carriage system, the paper feed system, and the print head system to the job control unit 77 corresponding to each lower layer for control.

  The job control unit 77 has a function of adjusting instructions from the control units 75 and 76, which are upper layers, and includes a request unit 91 therein. The request unit 91 controls various requests (carriage activation request, paper feed start request, ink ejection start request, flushing request, etc.) according to the instruction received from the upper layer by the job control unit 77 according to the priority order. The data is output to the sequence control unit 80 corresponding to the lower layer.

  The sequence control unit 80 performs sequence control for performing operations according to the received request in an appropriate order and timing, and includes a PF control unit 92, a CR control unit 93, and a head control unit 94 therein. The PF control unit 92 performs sequence control of the PF motor 52 via the PF driver 69 according to the requested content, and performs a feeding operation, a paper feeding operation, a paper discharging operation, and the like. The CR control unit 93 performs sequence control of the CR motor 33 via the CR driver 70 according to the requested content, and performs a carriage operation during a printing operation or a flushing operation. Further, the head controller 94 controls the drive element for each nozzle 43 of the print head 42 via the head driver 71 according to the requested content, and from the nozzle 43 for the requested printing operation or flushing operation. Ink droplets are ejected.

  Reception data such as print job data D1 received from the host device HC is stored in the reception buffer 67a. The print job data D1 includes one divided image data D2 obtained by dividing image data for one page by one pass, and a command for instructing printing and paper feeding for one pass. Further, the print job data D1 that the printing apparatus 11 first receives in one job includes print condition information (print mode, paper type, paper size, etc.) input and set by the user to the host device HC. The print control unit 75 analyzes the printing method (band printing, microweave printing, etc.) from the printing mode, and determines the nozzle assignment method according to the printing method of each dot (print pixel) of the divided image data D2. The print control unit 75 analyzes the command in the print job data D1 read from the reception buffer 67a, outputs an instruction based on the analysis result to the job control unit 77, and stores the divided image data D2 in the intermediate buffer 67b. .

  The image processing unit 78 develops the divided image data D2 stored in the intermediate buffer 67b. At this time, the image processing unit 78 assigns dot data to the nozzles in accordance with the printing method, and arranges the assigned dot data in the order corresponding to the ejection order corresponding to the carriage movement direction, for head control. Print data D3 (head control data) is generated. The print data D3 is stored in the output buffer 67c. Thus, the image processing unit 78 constructs print data D3 in which dot data is arranged in the order of the ink ejection order corresponding to the carriage movement direction.

  The transfer unit 79 transfers the print data D3 stored in the output buffer 67c to the head control unit 94 for each pass. The head controller 94 drives and controls the drive elements for each nozzle via the head driver 71 based on the print data D3, and forms a print image on the roll paper P by ejecting ink droplets from the nozzles 43. Since the print data D3 is constructed by arranging dots in the order corresponding to the moving direction (scanning direction) of the carriage 32, the movement of the carriage 32 does not depend on the forward or backward movement, but by the print head 42 for each pass. Images are printed correctly.

  Here, the flushing control performed by the flushing control unit 76 by controlling the carriage 32 will be described with reference to FIG. FIG. 6 is a schematic diagram for explaining the operation of the carriage 32 during flushing. In FIG. 6, the paper feed of the roll paper P in the sub-scanning direction Y is indicated by the relative movement of the carriage 32 in the anti-Y direction. Conventionally (FIG. 12), the carriage is started after waiting for the flushing necessary condition time Tfc to elapse. In this embodiment, the estimated waiting time until the next pass is calculated as the estimated paper feed standby time. Calculate as Tw. Then, when the predicted paper feed standby time Tw exceeds the necessary flushing condition time Tfc (first set time), the flushing control unit 76 does not wait for the flushing necessary condition time Tfc (second set time) to pass and immediately The carriage 32 is activated toward a flushing position FP (in this example, a home position HP) that is an example of a preparation operation position.

  In the printing apparatus 11 that is a serial printer, a print image for one page is printed on the roll paper P by the carriage 32 performing printing in a plurality of passes. For example, the carriage 32 that has moved in the forward direction and finished printing (n) of the Nth pass stops at the full-side stop position PTn (print (n) end position) as shown in FIG. In this example, the Nth paper feed (n) is started prior to this stop. By this paper feed (n), the roll paper P is conveyed by the paper feed length Lpf in the sub-scanning direction Y from the Nth print (n) position to the print (n + 1) position scheduled to be printed in the N + 1th pass. . At this time, the carriage 32 waits at the full stop position PTn until the roll paper P is conveyed to a position where the next pass can be started.

  In FIG. 6, the total time required for the carriage 32 that has started moving from the full standby position PTn to finish flushing at the flushing position FP (hereinafter also referred to as “flushing total required time Ttf”) is the carriage movement. It is indicated by the sum of the time Tth, the flushing standby time Tfw, and the flushing operation time Tf (Ttf = Tth + Tfw + Tf). Here, the carriage movement time Tth indicates the time required for the carriage 32 to reach the flushing position FP from the standby position PTn. The flushing standby time Tfw is set so that the start time of the flushing operation is just the timing at which the N + 1th pass can be started immediately after the end of the flushing operation. That is, the waiting time for time adjustment so that the flushing operation ends immediately before the carriage 32 starts moving the next pass is the flushing waiting time Tfw. For this reason, the flushing waiting time Tfw may not be set (that is, Tfw = 0). In the present embodiment, the flushing necessary condition time Tfc is set to a predetermined value within a range of 500 to 3000 milliseconds, for example.

  Further, in the bidirectional printing mode, the print data D3 that has already been constructed on the premise of the full-side → home-side carriage movement direction (return direction) so that the next pass can be started from the home position HP after flushing. (Head control data) is reconstructed so that printing (ink droplet ejection) is possible in a path in the carriage movement direction (return path direction) from the home side to the full side. As shown in FIG. 5, the image processing unit 78 includes a data reconstruction unit 95 as an example of a changing unit. When the carriage 32 is moved from the full side to the home side during flushing, the flushing control unit 76 outputs a data reconstruction request to the print control unit 75. The print control unit 75 that has received this request outputs a reconstruction command to the image processing unit 78. In the image processing unit 78 that has received this reconstruction command, the data reconstruction unit 95 has already been constructed for the next (N + 1) th pass that has been constructed in the dot arrangement order that matches the carriage movement direction from the full side to the home side. The print data D3 is reconstructed in a dot arrangement order that matches the carriage movement direction (forward direction) from the home side to the full side. As shown in FIG. 6, this data reconstruction is completed until the carriage 32 starts moving from the standby position PTn and ends the flushing operation. In other words, the reconstruction of the print data D3 ends after the time (Tfh + Tfw + Tf) elapses after the carriage 32 starts moving from the standby position PTn. For this reason, the data reconstruction required time Tdr is not included in the total flushing required time Ttf.

  Next, control contents and processing contents performed by the print control unit 75 will be described. The main control unit 81 controls the entire print control performed by the print control unit 75 and controls the units 82 to 85. The command analysis unit 82 divides the print job data D1 read from the reception buffer 67a into commands and divided image data D2. Then, the command is analyzed (interpreted), and a request corresponding to the analysis result is output to the job control unit 77. As a result, the print control unit 75 gives various instructions including a feeding instruction, a printing instruction, a paper feeding instruction, and a paper discharging instruction to the job control unit 77 according to the analysis result of the command analysis unit 82.

  The data analysis unit 83 analyzes the divided image data D2, and the ink ejection start position (also referred to as the first dot position Fn) when the carriage 32 moves in the main scanning direction and the print head 42 performs printing for one pass. The ink ejection end position (also referred to as the last dot position Ln) is acquired. Here, the subscript “n” between the first dot position Fn and the last dot position Ln indicates the Nth pass. Further, the data analysis unit 83 acquires the start position PSn and the stop position PTn of the carriage 32 when the carriage 32 moves for one pass in the main scanning direction X.

  FIG. 7 is a timing chart showing the relationship between the printing operation and the paper feeding operation. 7 is a graph showing the speed profile of the carriage 32. In this graph, the horizontal axis represents the carriage position x and the vertical axis represents the carriage speed V. 7 is a graph showing the speed profile of the paper feeding operation. In this graph, the horizontal axis represents the transport position of the roll paper P, and the vertical axis represents the transport speed of the roll paper P. FIG. 7 also shows the time required for carriage movement or paper feed in the section in the horizontal axis direction.

  As shown in the upper graph of FIG. 7, the speed profile during the one-pass operation (for example, the N-th pass operation) of the carriage 32 includes the acceleration region from the start position PSn of the carriage 32 to the constant speed region, and the carriage 32. Includes a constant speed area in which the carriage 32 moves at a constant speed and a deceleration area in which the carriage 32 decelerates from the constant speed and stops at the stop position PTn. In the example of FIG. 7, printing (ink droplet ejection) is performed in an ink ejection area that is hatched in a constant speed area.

  The calculation unit 84 calculates the starting position PSn by adding the acceleration distance Da (running distance) to the first dot position Fn acquired by the data analysis unit 83 on the side opposite to the carriage movement direction, and the data analysis unit 83 acquires The stop position PTn is calculated by adding the deceleration distance Db (braking distance) to the last dot position Ln on the carriage movement direction side (see FIG. 7). Note that acceleration / deceleration printing control in which ink ejection is started in the middle of the acceleration region of the carriage 32 and ink ejection is terminated in the middle of the deceleration region may be employed.

  The paper feed length acquisition unit 85 acquires the paper feed length Lpf (conveyance length) set in the paper feed command. The main control unit 81 selects a PF speed table (not shown) of the conveyance speed corresponding to the paper feed length Lpf, and outputs a paper feed command to the job control unit 77 together with the paper feed information. These pieces of paper feed information are also sent to the flushing control unit 76 for use in calculating the paper feed standby waiting time Tw.

  Further, in the present embodiment, as shown in FIG. 7, PF / CR superposition control in which the printing operation and the paper feeding operation are partially overlapped in timing is adopted. That is, as shown in FIG. 7, the print control unit 75 starts the paper feeding operation at the time when the ejection of ink droplets is completed (the last dot formation time), and the carriage 32 activated for the next pass forms the first dot. The carriage 32 is started earlier by the time ΔT than the end of the paper feeding operation so that the timing when the roll paper P stops when reaching the position.

  The calculation unit 84 calculates a CR movement required time ΔT (acceleration required time in this example) from the carriage activation position PSn + 1 of the next pass to the first dot position Fn + 1. Further, the calculation unit 84 calculates a conveyance amount ΔS (conveyance distance) corresponding to the CR movement required time ΔT in the direction opposite to the paper conveyance direction from the current paper conveyance end position PEn (stop position), and the paper conveyance end position PEn. Then, a position just before the transport amount ΔS is calculated as a CR activation request position. The carry amount ΔS is notified to the job control unit 77. The job control unit 77 grasps the remaining transport amount ΔSr up to the paper transport end position PEn from the count value of the PF counter (not shown) during the Nth paper transport operation, and the remaining transport amount ΔSr reaches the transport amount ΔS. At the time (that is, when the carriage 32 reaches the CR activation request position), a carriage activation request is output to the CR control unit 93 (see FIG. 7). The PF control unit 92 sets the paper feed length Lpf to the PF counter (not shown) at the start of paper feeding, and sequentially subtracts the number of encoder pulses input from the rotary encoder for conveyance (not shown) from this count value. Thus, the remaining transport amount ΔSr is managed based on the count value of the PF counter. The job control unit 77 monitors the remaining transport amount ΔSr managed by the PF control unit 92 and outputs a carriage activation request to the CR control unit 93 when the remaining transport amount ΔSr reaches the transport amount ΔS.

  The CR controller 93 counts the position of the carriage 32 in the main scanning direction X (hereinafter referred to as “carriage position”) based on the encoder pulse signal from the linear encoder 38. The CR control unit 93 determines the level (Hi or Low) of the other pulse when detecting one rising edge of the two-phase encoder pulse signals input from the linear encoder 38 when the carriage is driven, and according to the determination result. To grasp the carriage movement direction. The CR control unit 93 increments the count value of the CR counter (not shown) reset when the carriage 32 is placed at the home position in the forward movement process of the carriage 32 (when moving from the home to the full direction), and moves backward. By decrementing in the process (when moving from full to home), the carriage position with the home position HP as the origin is managed. The CR control unit 93 monitors the carriage position x from the starting position PSn of the carriage 32 and refers to the CR speed table (CR speed profile data) to set a command value corresponding to the target speed corresponding to each carriage position x. Output to the driver 70.

  The job control unit 77 monitors the carriage position (that is, the position of the print head 42) from the count value of the CR counter during the printing operation for one pass, and the timing at which the print head 42 reaches the first dot position Fn. Then, an ink ejection start request is output to the head controller 94. The head controller 94 that has received this request outputs a start signal to the head driver 71 to start ink droplet ejection when the print head 42 reaches the first dot position Fn. When the print head 42 reaches the last dot position Ln, the head control unit 94 responds to the job control unit 77 that the printing operation is completed. Upon receiving this response, the job control unit 77 outputs a paper feed request to the PF control unit 92. The PF control unit 92 that has received this request starts the paper feeding operation by driving the PF motor 52 via the PF driver 69. Thus, when the ink droplet ejection is completed in the Nth pass, the Nth paper feed is started, and the N + 1th pass of the carriage 32 is performed by the time ΔT before the time when the roll paper P stops at the stop position PEn. It is activated.

  In the present embodiment, a carriage control method called superlogical seek is adopted during printing operation (moving) of the carriage 32. In this carriage control method, the current stop position PTn determined from the current last dot position Ln is compared with the next start position PSn + 1 determined from the next first dot position Fn + 1, and PTn and PSn + 1 are compared. The next stop position (N + 1) is determined as the current stop position while the next acceleration distance Da (running distance) is secured.

  FIG. 8 is a graph for explaining this carriage control method. A carriage control method by super logical seek performed by the print control unit 75 will be described using a graph showing the Nth printing operation in the upper stage in FIG. 8 and a graph showing the N + 1th printing operation in the middle stage.

  The computing unit 84 adds the acceleration distance Da to the N + 1th (next) first dot position Fn + 1 on the Nth carriage movement direction side while the carriage 32 performs the Nth (current) main scan. Then, the N + 1th carriage activation position PSn + 1 is calculated. Then, the main control unit 81 compares the current carriage stop position PTn with the next carriage start position PSn + 1, and determines one position farther in the current carriage movement direction as the current stop position PTn. To do. As in the example of FIG. 8, if the N + 1th carriage activation position PSn + 1 is further than the Nth carriage movement position ahead of the Nth carriage stop position PTn, the Nth stop position PTn (FIG. (N + 1) carriage start position PSn + 1 is changed to the Nth (current) new stop position PTn (solid arrow end point in the upper graph of FIG. 8) Set.

  Thus, the stop position PTn at the end of one pass of the carriage 32 changes for each pass. Accordingly, the carriage movement time Tfh required for the carriage 32 to move from the full stop position PTn (standby position) to the flushing position FP changes according to the standby position at that time.

  Further, as shown in the lower graph in FIG. 8, the CR movement required for the carriage 32 started from the flushing position FP (that is, the home position HP) to reach the next (N + 1) first dot position Fn + 1 is required. The time ΔT (corresponding to ΔT in FIG. 7) changes according to the distance from the flushing position FP to the next (N + 1) first dot position Fn + 1. For this reason, the remaining transport amount ΔSr (see FIG. 7) corresponding to the CR movement required time ΔT also changes, and the carriage activation timing during the paper feeding operation changes according to the next first dot position Fn + 1. Become.

  Next, details of the control and processing of the flushing control unit 76 will be described. The flushing control unit 76 controls flushing to be performed when a predetermined condition is satisfied during printing. As described above, the flushing control unit 76 includes the calculation unit 86, the first determination unit 87, the second determination unit 88, the third determination unit 89, and the timer 90 illustrated in FIG.

  The computing unit 86 computes the estimated paper feed standby time Tw. Specifically, when the carriage 32 stops at the full side or the home side according to the movement direction of the current (Nth) pass, the calculation unit 86 receives the current (Nth) paper currently being executed from the print control unit 75. The paper feed length Lpf in the feed and the PF speed table in use for the current (Nth) paper feed are acquired. Then, the calculation unit 86 calculates a predicted paper feed standby time Tw that is a predicted value of the standby time until the carriage 32 is activated in the next (N + 1) th pass for the paper feed operation of the paper feed length Lpf. As shown in FIG. 7, when the carriage 32 stops at the current (Nth) pass, a required time ΔTd from the last dot position Ln to the stop at the stop position PTn has elapsed. Based on the paper feed length Lpf and the PF speed table (PF speed profile data), the calculation unit 84 first calculates a paper feed required time Tpf (see FIG. 7) that is a time required for the paper feed operation. Then, the calculation unit 84 subtracts the required times ΔTd and ΔT from the required paper feed time Tpf to calculate the predicted paper feed standby time Tw using the equation Tw = Tpf−ΔT−ΔTd (see FIG. 7).

  The first determination unit 87 determines whether or not the estimated paper feed standby time Tw exceeds the flushing necessary condition time Tfc (Tw> Tfc is satisfied). When the condition Tw> Tfc is satisfied, the flushing control unit 76 instructs the job control unit 77 to perform flushing and requests the print control unit 75 to generate dot data for flushing. When receiving the flushing instruction, the job control unit 77 controls the CR motor 33 so that the CR control unit 93 moves the carriage 32 to the flushing position FP. In addition, the print control unit 75 reads the flushing dot data from a predetermined storage area of the nonvolatile memory 66 and stores it in the intermediate buffer 67b. Then, the image processing unit 78 generates flushing ejection data based on the flushing dot data and stores it in the output buffer 67c. In the present embodiment, the calculation unit 86 and the first determination unit 87 constitute a determination unit.

  The second determination unit 88 determines whether or not the moving direction of the carriage 32 to the flushing position FP is a direction from the full side toward the home side. For example, the second determination unit 88 stores the carriage position before the start of movement (that is, waiting), and determines that the moving direction is the direction from the full side toward the home side if it is the full side. On the other hand, if the carriage position before the start of movement is the home side, it is determined that the moving direction is not the direction from the full side toward the home side. In this way, the second determination unit 88 determines whether or not the carriage 32 has moved from the full side (second side) to the home side (first side) of both sides of the movement path during flushing.

  In the present embodiment, the timer 90 starts counting every time the carriage 32 stops after completing one pass, and measures the elapsed time T during stoppage (standby). That is, the timer 90 measures the elapsed time T (that is, the actual waiting time T) from when the carriage 32 that has completed the current (Nth) pass stops at the stop position PTn until it starts for the next pass. To do. The third determination unit 89 determines whether or not the actual standby time T of the carriage 32 has exceeded the flushing necessary condition time Tfc.

Next, a print processing routine executed by the computer 62 of this embodiment will be described based on the flowchart shown in FIG.
In the printing apparatus 11, a print processing routine is executed at the timing when reception of the print job data D1 from the host apparatus HC is started. Then, first, the computer 62 performs a print start process. Specifically, the computer 62 controls the PF motor 52 so that the leading edge of the roll paper P enters the ink ejection unit 22. The computer 62 (command analysis unit 82) analyzes header information included in the print job data D1 temporarily stored in the reception buffer 67a. Here, the command analysis unit 82 determines the print mode (high-definition mode / draft mode) and the printing method (bidirectional printing / unidirectional printing) from the header information in the print job data D1 transmitted from the host device HC at the beginning of the job. ), Print color information such as print color (color / gray scale) and paper size. Thereafter, the computer 62 executes a printing process according to the flowchart of FIG. In the following flowchart, an example of the bidirectional printing mode will be described.

  First, in step S10, print data is generated. That is, the command analysis unit 82 analyzes the command in the print job data D1 to acquire the paper feed length Lpf and the like, and the data analysis unit 83 performs data analysis of the divided image data D2 to acquire the dot positions Fn and Ln. To do. Further, the image processing unit 78 performs predetermined processing such as development processing and nozzle allocation processing on the divided image data D2 to generate print data D3. Note that the print operation is started in a state where the print data D3 for a plurality of passes can be stored in the output buffer 67c. In S10 at the N-th print, the pass (for example, the N + 1th pass) is more than one pass. Print data D3 is generated. This is to avoid a situation in which the next start-up timing of the carriage 32 is delayed because the print data D3 cannot be generated.

  In step S20, a printing process is performed. Specifically, the CR motor 33 is driven to cause the carriage 32 to perform one scan (one-pass operation), and the drive element for each nozzle is driven via the head driver 71 based on the Nth print data D3. Printing for one pass is performed by ejecting ink droplets from the nozzles 43 during one scan.

  In step S30, a paper feed process is performed. The job control unit 77 outputs a paper feed request to the PF control unit 92 at the timing when the Nth ink ejection is completed. Upon receipt of this paper feed request, the PF control unit 92 starts driving the PF motor 52 and controls the speed of the PF motor 52 with reference to the designated PF speed table, whereby the roll paper P is fed by the paper feed length Lpf. Start the paper feeding operation. At this time, as shown in FIG. 7, the paper feed request is output immediately after reaching the current (Nth) last dot position Ln, and the paper feed operation is started immediately after the last dot formation during the printing operation. -CR overlay control is performed. Thereafter, the carriage 32 stops at the current stop position PTn with a delay of time ΔTd from the paper feed start time.

  In step S40, a predicted paper feed standby time Tw is calculated between the start of paper feed and the stop of the carriage 32. However, this calculation may be performed before the paper feeding operation is started, or may be performed immediately after the carriage 32 is stopped if the calculation required time is short enough to be ignored. This calculation is performed as follows. First, the computing unit 86 calculates the paper feed required time Tpf shown in FIG. 7 with reference to the paper feed length Lpf and the PF speed table (PF speed profile data). Next, a CR movement required time ΔTd from the paper feed start time (in this example, the last dot Ln formation end time) until the carriage 32 stops at the current (Nth) stop position PTn is calculated, and the next (N + 1) th time is calculated. ) CR movement required time ΔT, which is the time required for the carriage 32 to move from the pass starting position PSn + 1 to the first dot position Fn + 1, is calculated. Then, the estimated paper feed standby time Tw is calculated by the equation Tw = Tpf−ΔTd−ΔT.

  In step S50, it is determined whether or not the estimated paper feed standby time Tw exceeds the flushing necessary condition time Tfc. Specifically, this determination is performed by the first determination unit 87. When Tw> Tfc is established, the process proceeds to step S60, and when Tw> Tfc is not established, the process proceeds to step S120.

  In step S60, the carriage 32 is moved to the home side flushing position. In this case, if the carriage 32 is stopped (standby) at the full stop position PTn in the current pass, as shown in FIG. 6, the carriage 32 is at the full stop position PTn (print (n) end position). To the home side flushing position FP. When the carriage 32 is stopped at the home-side stop position PTn in the current pass, the carriage 32 moves from the home-side standby position to the same home-side flushing position. In this case, the carriage 32 only needs to move slightly in the backward movement direction.

  In step S70, (1) a flushing method corresponding to the estimated paper feed standby time Tw and the printing ink amount Vi is determined, and (2) a flushing start timing Tst at which flushing can be completed immediately before starting the next pass printing is calculated. .

  In the flushing method, the stronger the flushing waiting time Tw, the stronger the flushing is performed. The intensity of the flushing is adjusted by the number of times of flushing and the ink ejection amount (ink ejection amount / time) per flushing. In other words, the longer the paper feed standby time Tw is, the more the ink viscosity increases. Therefore, the longer the paper feed standby time Tw is, the higher the flushing strength is. Further, the printing ink amount Vi used for printing the remaining printing area in the same page after the paper feed is completed is obtained, and the flushing intensity is adjusted according to the printing ink amount Vi. As the printing ink amount Vi increases and the remaining printing amount increases, the flushing strength is increased. This is because the higher the flushing strength, the lower the dot drop occurrence probability, and the higher the remaining printing amount, the higher the number of dot drop occurrences under the same dot drop occurrence probability. In order to suppress the number of missing dots to “0” as much as possible, the stronger the flushing is performed as the remaining printing amount (that is, the printing ink amount Vi) increases.

  Specifically, in this example, a flushing intensity determination table that associates the number of times flushing and the amount / time of ink ejection for each combination of values of the estimated paper feed standby time Tw and the printing ink amount Vi is a non-volatile memory. 66. Then, the flushing control unit 76 refers to the flushing strength determination table based on the calculated estimated paper feed standby time Tw and the printing ink amount Vi, and performs an appropriate flushing strength (flushing number, flushing) according to these values Tw and Vi. Ink ejection amount / time) is determined.

  The flushing start time Tst is calculated as follows. The timer 90 measures the elapsed time T after the carriage 32 stops at the current (Nth) stop position PTn, and this elapsed time T exceeds the estimated paper feed standby time Tw (T> Tw). Is the carriage activation timing of the next (N + 1) th pass. The flushing start timing Tst is earlier than the carriage activation timing of the next pass by the flushing operation time Tf. Therefore, the calculation unit 86 calculates the flushing start time (time) Tst by the formula Tst = Tw−Tf. The time when the elapsed time T reaches the flushing start time Tst is the flushing start time at which the flushing operation should be started.

  In the next step S80, it is determined whether or not the carriage movement to the flushing position is a movement from the full direction to the home direction. This determination is performed by the second determination unit 88. The flushing control unit 76, for example, stores standby position information (for example, a flag) indicating whether the standby position before starting the movement to the flushing position is the home side or the full side, at a predetermined value in the RAM 67 for each pass. Store in the storage area. The second determination unit 88 determines whether or not the movement is in the full → home direction based on the standby position information. For example, if the standby position information is a value “1” indicating the full side, it is determined that the movement is in the full → home direction, and if the standby position information is “0” indicating the home side, the full → home direction is determined. It is determined not to move. If the determination is affirmative (flag “1”), the second determination unit 88 proceeds to step S90. If the determination is negative (flag “0”), the processing proceeds to step S100.

  In step S90, the print data is reconstructed from home to full. That is, the print data D3 constructed in the dot formation order in the full → home direction in accordance with the carriage movement direction of the next pass is reconstructed so that the dot formation order in the home → full direction is obtained. As a result of the reconstruction of the data, the carriage 32 is activated from the flushing position FP, and the next printing can be started from the home side.

  In step S100, it is determined whether or not the flushing start time Tst has been reached. That is, the flushing control unit 76 determines whether or not the elapsed time T has reached the flushing start time Tst. If T ≧ Tst is not established, the process waits until it is established, while if T ≧ Tst is established, the process proceeds to step S110.

  Here, when the carriage 32 has reached the flushing position FP before reaching the flushing start time Tst, as shown in FIG. 6, a flushing waiting time Tfw occurs until the flushing start time Tst is reached. On the other hand, if the carriage 32 reaches the flushing position FP after reaching the flushing start time Tst, the flushing operation is started immediately after reaching the flushing position FP. The carriage movement time Tfh in the full-to-home direction shown in FIG. 7 differs depending on the standby position PTn determined for each pass. When Tst> Tfh, the flushing standby time Tfw occurs, but when Tst ≦ Tfh, the flushing time Tfh is generated. The waiting time Tfw does not occur, and the flushing operation starts immediately after reaching the flushing position FP. A configuration may be adopted in which the calculation unit 86 calculates the flushing standby time Tfw and starts flushing when the elapsed time after the carriage 32 reaches the flushing position reaches the flushing standby time Tfw. The flushing waiting time Tfw is calculated by, for example, the equation Tfw = Tst−Tfh. If Tfw> 0, the value is adopted as the flushing waiting time, and if Tfw ≦ 0, Tfw = 0.

  In step S110, flushing is executed by the determined method. However, if the carriage 32 has not yet reached the flushing position FP when T ≧ Tst is established, the flushing is executed immediately after the arrival. In the process of S110, the flushing is executed by the flushing method determined in step S70. As a result, the flushing with higher flushing strength (flushing frequency, ink ejection amount / time) is performed as the estimated paper transport standby time Tw is longer and the printing ink amount Vi is larger. For this reason, the number of missing dots can be suppressed to “0” as much as possible in the remaining printing in the same page performed after the flushing.

  In step S140, it is determined whether printing is finished. If all passes have not been completed and printing has not ended, the process returns to step S10, and the same processing is repeated for each pass until all passes have been completed.

  In step S20 in the (n + 1) th time, the next (N + 1th) pass printing process is performed. Since the printing process of the (N + 1) th pass is performed based on the reconstructed print data D3, the image can be correctly printed even when the carriage 32 is activated from the flushing position (home side).

  On the other hand, if Tw> Tfc is not established in step S50, in step S120, an elapsed time T (actual waiting time T) from when the timer 90 stops after finishing the Nth pass of the carriage 32 is measured. To do. In step S130, the third determination unit 89 determines whether or not the elapsed time T has exceeded the necessary flushing condition time Tfc. When T> Tfc is satisfied, the carriage 32 is moved to the flushing position (S60), and after performing the processes of S70 to S90, the flushing is executed when the flushing start time Tst is reached (S100, S110).

  For example, if the user accidentally opens the main body cover 25 during printing, the operation of the printing apparatus 11 may be stopped for safety. When the actual waiting time T exceeds the necessary flushing time Tfc contrary to prediction for some reason such as the stop of the printing apparatus 11, flushing is performed. For this reason, contrary to the prediction of the standby time, when the actual standby time T exceeds the flushing requirement time Tfc (T> Tfc), flushing is performed as in the conventional case. Even when the actual waiting time T exceeds the flushing necessary condition time Tfc and flushing is performed as described above, the print data D3 is reconstructed (S90), and when the flushing operation is finished, the flushing position FP is changed to N + 1. Start the second pass.

  If the actual waiting time (elapsed time T) does not exceed the flushing necessary condition time Tfc as expected, the carriage 32 starts the next (N + 1) th pass before T> Tfc is satisfied. Flushing (preparation operation) is not performed.

As described in detail above, according to the first embodiment, the following effects can be obtained.
(1) It is determined whether or not the estimated paper feed standby time Tw until the carriage 32 stopped after the Nth printing starts the N + 1th printing exceeds the flushing necessary condition time Tfc (first set time). Predict. As a result of the prediction, when Tw> Tfc is established, the flushing necessary condition time Tfc (second set time (= first set time) set as a waiting time until the movement for the flushing (preparation operation) is started. The movement of the carriage 32 to the flushing position is started immediately without waiting for the time)) to elapse. As a result, since the movement of the carriage 32 can be started earlier by the flushing required time Tfc as compared with the conventional technique (FIG. 12), the delay of the (N + 1) th printing start time performed after the flushing can be reduced as much as possible, and the printing throughput can be improved.

  (2) Preparatory operation when the paper feed standby waiting time Tw exceeds the flushing requirement time Tfc (second set time) set as a waiting time required until the carriage 32 starts to move for the preparatory operation. Is adopted as a first set time set as a criterion for starting the process. Therefore, when it is predicted that the preparation operation is to be performed from the estimated paper feed standby time Tw, the movement of the carriage 32 is always started immediately, so that the total required time Ttf can be shortened in almost all the flushing operations. Throughput can be improved.

  (4) Since the calculation unit 86 calculates the flushing start time (time) Tst at which flushing can be finished immediately before starting the next pass, the first ink droplet ejection is performed in the next pass after the flushing is finished. Can be made as short as possible. Accordingly, since ink droplets can be ejected by the nozzle 43 that has just been flushed, printing from the next pass can be performed relatively well.

  (5) Switch between at least one of the number of times and the strength of flushing according to the length of the estimated paper feed standby time Tw and the remaining print amount to be printed after paper feed. Therefore, printing after flushing can be performed satisfactorily. For example, when there is a possibility that the ink in the nozzle dries due to a long paper feeding time, the number of times of prior flushing is performed frequently or flushing is performed with a strong jet force. Further, as the remaining print image data amount increases, the number of times of prior flushing is increased, or flushing is performed with a strong jet force.

  (6) When the carriage 32 moves from the full side to the home side for performing flushing, the print data D3 is reconstructed in the dot order that allows the next pass to be started from the flushing position on the home side. Therefore, when the carriage 32 is moved from the full side to the home side for flushing, the movement of the next path can be started from the destination home side without returning to the original full position after the flushing. As a result, there is no need to return the carriage 32 from the flushing position FP to the original full stop position PTn after the flushing. This can further reduce the frequency at which the next pass cannot be started. Further, since the reconstruction of the print data D3 is completed by the end of the flushing operation of the print head 42, the delay in the start time of the next pass of the carriage 32 can be avoided due to the delay in the reconstruction of the print data D3. . Therefore, the printing throughput can be improved.

  (7) Even if it is determined that the estimated paper transport standby time Tw does not exceed the necessary flushing condition time Tfc (Tw> Tfc is not established), the actual elapsed time (waiting time) T is thereafter the flushing necessary condition time. When Tfc is exceeded, the carriage 32 is moved to the home side flushing position FP to perform flushing. As a result, if the actual standby time T exceeds the flushing requirement time Tfc contrary to prediction due to some reason, for example, the user opens the main body cover 25 for a moment and the paper feeding operation is temporarily interrupted, Flushing can be performed.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. In the second embodiment, the carriage control method at the time of flushing is different from that of the first embodiment. In the following, a description will be given centering on particularly different parts according to the flowchart of FIG. In the second embodiment, the carriage 32 starts to move to the flushing position after waiting for the flushing necessary condition time Tfc to elapse, as in the prior art (FIG. 12). However, if it is predicted that a delay will occur at the start time of the next path movement after waiting for the flushing necessary condition time Tfc to elapse, the carriage immediately does not wait for the flushing necessary condition time Tfc to elapse. The movement to the flushing position FP of 32 is started.

  In FIG. 10, each process of S210-S230, S250 is the same as each process of S10-S40 in FIG. Further, each process of S270 to S350 is the same as each process of S60 to S140 in FIG.

  In step S240, it is determined whether or not the stop position PTn of the carriage 32 that will stop or stop after the Nth pass is the full side (second side) position. That is, it is determined whether or not the standby position of the carriage 32 is the full side opposite to the home side (first side) where the flushing position FP is located in the path in the main scanning direction X. If it is determined that the standby position of the carriage 32 is the full side, the process proceeds to step S250, and if it is determined that the carriage 32 is not the full side, the process proceeds to step S330.

  In step S250, the estimated paper feed standby time Tw is calculated. In the next step S260, it is determined whether or not the estimated paper feed standby time Tw is shorter than the total flushing required time Ttf and longer than the necessary flushing condition time Tfc. That is, it is determined whether or not Ttf> Tw> Tfc is satisfied. This determination is performed by the first determination unit 87. Here, in this example, the total flushing required time Ttf corresponds to the waiting time until the next pass is started when the waiting carriage 32 moves to the flushing position FP and performs flushing. Further, the estimated paper feed standby time Tw corresponds to the maximum allowable standby time (first set time) at which the next pass can be started without a delay in the start time of the next pass. As described above, the present embodiment is an example in which both the standby time for prediction (total flushing required time Ttf) and the first set time (predicted paper feed standby time Tw) are variable.

  As shown in FIG. 12, the total flushing required time Ttf is the sum of the required flushing time Tfc, the carriage moving time Tfh from the full standby position PTn to the flushing position FP, and the flushing operation time Tf (Ttf = Tfc + Tfh + Tf). ). In the present embodiment, since the carriage movement time Tfh is a value that changes in accordance with the standby position PTn of the carriage 32, the calculation unit 86 determines the distance between the standby position PTn and the flushing position FP, the CR speed table (CR speed). The carriage movement time Tfh corresponding to the standby position PTn is calculated based on the profile data. Then, the calculation unit 86 adds the flushing necessary condition time Tfc and the flushing operation time Tf to the carriage movement time Tfh, and calculates the total flushing required time Ttf (= Tfc + Tfh + Tf). Then, the first determination unit 87 determines whether or not Ttf> Tw> Tfc is satisfied by using the total flushing required time Ttf calculated by the calculation unit 86 and the estimated paper feed standby time Tw. In other words, in this embodiment, by determining whether or not Ttf> Tw> Tfc is satisfied, it is possible to predict that the predicted paper feed standby time Tw exceeds the required flushing condition time Tfc, and wait for the required flushing condition time Tfc. When the movement of the carriage 32 to the flushing position FP is started after that, it is determined whether or not a delay occurs at the start time of the next pass. In the present embodiment, the calculation unit 86 and the first determination unit 87 constitute a determination unit.

When Ttf>Tw> Tfc is established, the process proceeds to step S270, and each process of S270 to S320 is performed. On the other hand, if Ttf>Tw> Tfc is not established, the process proceeds to step S330.
In step S270, the carriage 32 starts moving from the standby position toward the flushing position FP. Here, the reason why Ttf>Tw> Tfc is satisfied is that Tw> Tfc is satisfied because the paper feed standby predicted time Tw is relatively long, and the paper transport standby predicted time Tw is not as long as the total flushing required time Ttf. Therefore, Ttf> Tw is satisfied. The establishment of Ttf> Tw means that when the carriage 32 starts moving to the flushing position FP after waiting for the flushing requirement time Tfc to elapse, a delay occurs in the next (N + 1) th path start time. To do. When the carriage 32 starts to move after waiting for the flushing requirement time Tfc to elapse in this way, if it is predicted that a delay will occur at the start time of the next (N + 1) th pass, the carriage 32 is set to the flushing requirement time. The movement is immediately started toward the flushing position FP without waiting for the passage of Tfc.

  Then, the flushing method is determined and the flushing start timing Tst is calculated (S280). If the movement direction of the carriage 32 during flushing is the movement from the full direction to the home direction (positive determination in S290), the print data D3 is obtained. The dot is rearranged in the home-to-full direction (S300). When the flushing start time Tst is reached (Yes in S310), the flushing is executed by the previously determined method (S320).

  On the other hand, when the standby position of the carriage 32 is on the home side (No determination in S240) and when the determination condition (Ttf> Tw> Tfc) is not satisfied, the carriage 32 finishes the Nth pass and stops in S330. Elapsed time T (actual standby time) is measured.

  In the next step S340, the third determination unit 89 determines whether or not T> Tfc is satisfied. Here, if it is determined that Ttf> Tw> Tfc is not satisfied in S260, if Tw ≦ Tfc, T> Tfc is satisfied except for some exceptions as in the determination process of S130 of the first embodiment. Without doing so, the N-th process is completed. Thus, if the elapsed time T does not exceed the flushing requirement time Tfc, the next pass is started from the stop position PTn. On the other hand, if Tw ≧ Ttf, that is, if a delay does not occur at the start time of the next pass even if the movement of the carriage 32 to the flushing position FP is started after waiting for the flushing requirement time Tfc to elapse, When the time T (actual standby time) exceeds the flushing requirement time Tfc, the process proceeds to step S270. That is, when the elapsed time T (actual standby time) exceeds the necessary flushing condition time Tfc (Yes in S340), the carriage 32 is moved from the standby position PTn to the flushing position FP to perform flushing (S270 to S320). .

As described above in detail, according to the second embodiment, the effects (4) to (7) in the first embodiment can be obtained similarly, and the following effects can be obtained.
(8) Flushing necessary time Tfc (second set time) when the total flushing required time Ttf (= Tfc + Tfh + Tf) (predicted standby time) exceeds the paper feed standby predicted time Tw (first set time) Without waiting for the elapse of time, the carriage 32 immediately started to move to the flushing position FP. That is, when the movement of the carriage 32 to the flushing position FP is started after the flushing necessary condition time Tfc has elapsed, if a delay occurs at the start time of the next pass, the carriage 32 moves to the flushing position FP. Start immediately. As a result, the frequency with which the start timing of the carriage 32 for the next pass is delayed can be reduced.

The present invention is not limited to the embodiments described above, and can be implemented in the following manner.
・ The timing can be changed as appropriate. For example, the timing at which the previous flushing is completed may be set as the timing timing. In this case, the sum of the predicted paper feed standby time Tw and the time from the timing to the time when the carriage 32 stops at the current (Nth) stop position PTn is the required flushing time Tfc (in this case, Tfc = flushing). It may be determined whether or not the interval time Tfi) is exceeded.

  -Regarding the time, the start timing and end timing that are actually measured can be set as other timings. And if the threshold value according to which timing is adopted is set, it can be made to operate | move on the same conditions after all.

-The structure which does not employ | adopt PF * CR superposition control may be sufficient. In this case, the estimated paper feed standby time Tw may be calculated by Tw = Tpf.
A configuration may be adopted in which the data reconstruction unit 95, which is an example of a changing unit, is abolished and data reconstruction processing is not performed. For example, as shown in FIG. 11, after the flushing, the carriage 32 is returned to the original standby position PTn on the full side, and this position is set as the next activation position PSn + 1 to start the next time from the full side. Even with this configuration, it is possible to reduce the frequency at which the next pass cannot be started even though the paper feed has progressed to the timing at which the next pass can be started.

  The preparatory operation for ensuring the printing capability of the printing means is not limited to the flushing operation. For example, cleaning may be employed as a preparatory operation when the printing quality is not significantly affected even if it is performed during printing and only a relatively short time is required. In short, it may be a preparatory operation for ensuring the printing capability of the printing means when a waiting time until the start of the next printing occurs during printing. Further, the preparatory operation for inspecting the printing capability is not limited to the nozzle inspection by the nozzle inspection unit 48. For example, it may be a size inspection in which the size of an ink drop or dot is measured to inspect whether or not it is an appropriate size.

  Although the flushing standby time Tfw is provided so as to finish the flushing immediately before starting the next pass, the flushing standby time Tfw may be abolished. In this case, flushing is performed immediately after the carriage 32 arrives at the flushing position FP. Also, two types of flushing may be performed: immediately after arrival of the flushing position FP and immediately before the next pass is started.

The switching of the flushing method may be abolished, and the flushing may always be performed under a certain condition (for example, one flushing with one strength).
A configuration in which the flushing box is provided on the full side and the flushing positions are two locations corresponding to the home side cap and the full side flushing box may be employed. The carriage 32 waiting for the start of the next pass on the full side immediately moves to the full flushing position before the flushing necessary condition time Tfc elapses when the condition of predicted paper feed standby time Tw> flushing necessary condition time Tfc is satisfied. Move and flush into the flushing box at the flushing position. Further, the flushing is always performed on the flushing box. When the condition Tw> Tfc is satisfied when the carriage 32 is on the home side, the carriage 32 is moved to the full flushing position without waiting for the passage of Tfc. A configuration can also be adopted.

-You may arrange | position a flushing receiving part and a nozzle test | inspection part on the opposite side respectively in both sides of a path | route.
Even if the determination condition Tw> Tfc is satisfied, if the elapsed time from the previous flushing execution time is within the flushing interval time Tfi, a configuration in which flushing is not performed can be employed.

  The determination condition for performing flushing is not limited to Tw> Tfc in which the flushing necessary condition time Tfc is the first set time. For example, even if the carriage 32 is immediately moved to the flushing position after the carriage 32 is stopped and the flushing is performed, it is predicted that the next pass cannot be started when the estimated paper feed standby time Tw has elapsed, and the start time of the next pass is delayed. In this case, it is possible to adopt a determination condition in which flushing is not performed. In this case, the determination condition is, for example, Tw> Tfh + Tf. Also, Tw> Tfc + Tfh + Tf may be used. Further, Tw> Tfc + Tfh + Tf + Tp may be satisfied. Here, Tp is the movement time from the flushing position of the carriage 32 to the first dot position of the next pass. As described above, when the first set time is set to “Tfh + Tf”, “Tfc + Tfh + Tf”, “Tfc + Tfh + Tf + Tp”, the flushing (preparation operation) is still finished even though the paper feed is advanced to the timing at which the next pass can be started. It is possible to avoid a situation in which the start time of the next path is delayed due to the fact that it is not.

  In each of the above embodiments, the actual standby time (elapsed time T) exceeds the first set time even when the predicted standby time does not exceed the first set time (flashing necessary condition time Tfc). In this case, the configuration is such that the preparatory operation is performed, but it is also possible to adopt a configuration in which only the predicted standby time is used for determination, and whether or not the actual standby time has exceeded the first set time is determined.

  Instead of moving the carriage 32 immediately (actual waiting time is substantially zero), the movement may be started after waiting for a predetermined time shorter than the flushing requirement time Tfc. Of course, the shorter the actual waiting time is, the better, but it is possible to start the movement to the flushing position after waiting for the time required for the flushing necessary condition time Tfc to e.g. 1/3, 1/2, 2/3. Good. In short, if the waiting time T for determining the start timing of the movement to the flushing position is shorter than the flushing requirement time Tfc, an effect corresponding to the short time can be obtained.

  The relative movement between the printing unit and the printing medium may be a configuration in which the printing medium moves in the main scanning direction with respect to the printing unit, or both the printing unit and the printing medium move, for example, in opposite directions to each other in the main scanning direction. The structure to do may be sufficient. As a means for moving the print medium, a movable table can be cited. This table is configured to reciprocate in the main scanning direction with the print medium adsorbed.

  -It is not limited to serial printers, but may be applied to line printers and page printers. In an example of a line printer and a page printer, a printing unit (for example, a print head) ejects ink droplets while being fixed at a printing position during printing, and ejects ink for relatively long conveyance of the printing medium. In the case where the standby time without waiting exceeds the first set time, a configuration in which the robot moves relative to the print medium for the preparation operation can be cited. In this case, the standby position is not the both sides of the path along which the printing unit such as a serial printer moves, but the printing position where printing is performed. In line printers and page printers, the relative movement of the printing unit with respect to the printing medium corresponds to the relative movement of the printing unit with, for example, conveyance in the conveyance direction of the printing medium. In this case, the relative movement direction at the time of printing and the relative movement direction at the time of the preparation operation may be different directions, for example, orthogonal to each other.

-The print medium is not limited to roll paper. A cut sheet may be used. The print medium is not limited to paper, and may be a film, metal, cloth, or the like.
The preparation means (nozzle inspection means) is not limited to the nozzle inspection section 48 that uses the electric charge charged in the ink droplets, and a nozzle inspection apparatus that uses laser light as in Patent Document 2 can also be employed. That is, for example, when laser light is irradiated so as to cross the ink droplet flight path of the inspection target nozzle and the injection operation of the inspection target nozzle is performed, it is determined as a normal nozzle if it is detected that the laser light is blocked, On the other hand, if it is not detected that the laser beam is blocked, it is determined that the nozzle is defective.

-You may implement each embodiment and a modification in combination with each other.
In each of the above embodiments, the ink jet printing apparatus 11 is employed, but a fluid ejecting apparatus that ejects or discharges a liquid (liquid material) other than ink may be employed as the printing apparatus. Good. The term “printing” as used herein is not limited to printing of images, documents, and the like in which a liquid such as ink is ejected to form a printing pixel, but widely “the liquid is ejected and the ejected liquid adheres to the medium. Is generally defined as “printing”. In this sense, the printing apparatus widely includes various liquid ejecting apparatuses including a liquid ejecting head that ejects a minute amount of liquid droplets. In this case, the droplet means a state of the liquid ejected from the liquid ejecting apparatus, and includes a liquid that is tailed in a granular shape, a tear shape, or a thread shape. The liquid here may be any material that can be ejected by the liquid ejecting apparatus. For example, it may be in a state in which the substance is in a liquid phase, such as a liquid with high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts ) And liquids as one state of the substance, as well as those obtained by dissolving, dispersing or mixing particles of a functional material made of solid materials such as pigments and metal particles in a solvent. Typical examples of the liquid include ink and liquid crystal. Here, the ink includes general water-based inks and oil-based inks, and various liquid compositions such as gel inks and hot-melt inks. As a specific example of the liquid ejecting apparatus, for example, a liquid containing a material such as an electrode material or a coloring material used for manufacturing a liquid crystal display, an EL (electroluminescence) display, a surface emitting display, a color filter, or the like in a dispersed or dissolved state. A liquid ejecting apparatus for ejecting may be used. Further, it may be a liquid ejecting apparatus that ejects a bio-organic matter used for biochip manufacture, a liquid ejecting apparatus that ejects a liquid as a sample that is used as a precision pipette, a printing apparatus, a microdispenser, or the like. Furthermore, in order to etch a liquid ejecting apparatus that ejects a transparent resin liquid such as an ultraviolet curable resin onto a substrate to form a micro hemispherical lens (optical lens) used for an optical communication element or the like, a substrate (printing medium), etc. Alternatively, a liquid ejecting apparatus that ejects an etching solution such as acid or alkali may be employed. The present invention can be applied to any one of these liquid ejecting apparatuses.

  DESCRIPTION OF SYMBOLS 11 ... Printing apparatus (liquid ejecting apparatus), 22 ... Ink jet part, 23 ... Conveying apparatus which is an example of a conveying means, 24 ... Paper discharge part, 25 ... Main body cover, 31 ... Guide shaft, 32 ... Carriage, 33 ... CR Motor 34, carriage drive unit 38, linear encoder 42, print head 43, nozzles 45, maintenance device 46, an example of a preparation unit used for preparatory operation for ensuring the printing capability of the printing unit Cap, 48... Nozzle inspection unit which is an example of preparation means used for preparation operation for inspecting printing capability of printing means, 52... PF motor constituting transport means, 60... Control circuit, 61. 62 ... Computer, 63 ... CPU, 64 ... ASIC, 65 ... ROM, 66 ... Non-volatile memory, 66a ... Flash Time information storage unit, 67 ... RAM, 67a ... receiving buffer constituting acquisition means, 69 ... PF driver, 70 ... CR driver, 71 ... head driver, 73 ... nozzle inspection voltage application circuit, 74 ... detection Circuit, 75... Print control section constituting control means, 76... Flushing control section constituting control means, 77... Job control section, 78... Image processing section, 80. Command analysis unit 83 ... Data analysis unit 84 ... Calculation unit 85 ... Paper feed length acquisition unit 86 ... Calculation unit as one example of determination unit, 87 ... First determination unit as one example of determination unit , 88... Second determination unit, 89... Third determination unit, 90... Timer, 91 .. request unit, 92 .. PF control unit, 93 ... CR control unit, 94. A data construction unit that is an example of a stage, P: roll paper that is an example of a print medium, PF: a flushing position as an example of a preparation operation position, HP: a home position, D1: print job data that constitutes print data, D2,. The divided image data constituting the print data, D3... Print data (head control data) constituting the print data, Tw... Is an example of the standby time in the first embodiment and the first set time (maximum in the second embodiment) Paper feed standby prediction time, which is an example of allowable standby time), Tfc ... flushing necessary condition time, Tfh ... carriage movement time, Tfw ... flushing standby time, Tf ... flushing operation time, Tst ... flushing start time (flushing start time), T: elapsed time (actual standby time), Vi: printing ink amount, Lpf: paper feed length (conveyance length), Tpf: paper Duration, Ttf ... which is an example flushing total duration of waiting time prediction in the second embodiment, Thf ... carriage moving time Ri.

Claims (8)

Acquisition means for acquiring print data;
Printing means for performing printing based on print data with relative movement to the print medium;
Preparation means used for a preparation operation for securing or inspecting the printing capability of the printing means;
A determination unit that predicts a standby time until the printing unit starts the next printing, and determines whether the standby time is longer than a first set time;
If it is determined that the waiting time is longer than the first set time, a second waiting time until the relative movement without printing to the preparation operation position where the preparation operation should be performed is set. Before the set time elapses, the printing unit starts relative movement to the preparatory operation position, and the preparatory operation is performed after the relative movement. On the other hand, the standby time is greater than the first set time. If it is determined that the length does not become longer, at least before the second set time elapses, control means for not starting relative movement of the printing means to the preparation operation position;
A printing apparatus comprising:   2. The control unit according to claim 1, wherein the control unit adjusts the start timing of the preparation operation to be performed after the relative movement of the printing unit to the preparation operation position in accordance with the start timing of the next printing. Printing device.   The control unit measures the actual standby time of the printing unit, and when the determination unit determines that the predicted standby time is not longer than the first set time, the actual standby time is 3. The printing apparatus according to claim 1, wherein when the second set time is exceeded, a relative movement of the printing unit to the preparation operation position is started.   The printing apparatus according to claim 1, wherein the first set time is substantially equal to the second set time. The standby time predicted by the determination unit is a standby time until the next printing is started when the printing unit performs the preparation operation before starting the next printing,
The first set time is a maximum allowable waiting time during which the predicted waiting time can start the next printing without a delay in the start time of the next printing. The printing apparatus according to claim 1. The preparatory operation is prepared in a plurality of types according to the difference in printing ability recovery ability or inspection ability of the printing means,
The control unit selects one of the plurality of types of the prepared operations corresponding to the waiting time or the remaining printing amount, and causes the printing unit to perform the selected one of the prepared operations. The printing apparatus according to any one of claims 1 to 5. The printing means performs printing by performing a reciprocal movement relative to the print medium;
The preparation operation position is set on a first side of both sides of a path in which the printing unit performs the reciprocating motion,
When the relative movement of the printing means to the preparatory operation position is performed from the second side opposite to the first side in the path toward the first side, the preparatory operation position 7. The apparatus according to claim 1, further comprising changing means for changing print data so that the printing means can start the next printing from the first side after performing the preparatory operation. The printing apparatus according to one item. Preparatory operation in a printing apparatus comprising: a printing unit that performs printing based on print data with relative movement with respect to a print medium; and a preparatory unit that is used for a preparatory operation for securing or inspecting the printing capability of the printing unit. A control method,
A determination procedure for predicting a standby time until the next printing of the printing unit is started, and determining whether or not the predicted standby time is longer than a first set time;
When it is determined that the waiting time is longer than the first set time, a second set time set as a waiting time until the relative movement to the preparation operation position where the preparation operation should be performed starts. Before, the relative movement to the preparatory operation position of the printing unit is started and the preparatory operation is performed after the relative movement, while the standby time is determined not to be longer than the first set time. In this case, at least before the second set time elapses, a control procedure for not starting relative movement of the printing unit to the preparation operation position;
A preparatory operation control method in a printing apparatus, comprising:

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