JP2013095004A - Printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress decrease of productivity in a printing device.SOLUTION: A control unit 11 executes change processing of a printing conveying speed when the setting printing conveying speed of a subsequent sheet is different with respect to the printing conveying speed set in a printing unit 3, and compares predicted required printing times including the time required for change processing of the printing conveying speed in the case when skipping and in the case when executing the change processing of the printing conveying speed in accordance with already obtained printing data when the subsequent sheet can be printed with the printing conveying speed being set even when the set printing conveying speed of the subsequent sheet is different with respect to the printing conveying speed set in the printing unit 3, and skips the change processing of the printing conveying speed when the predicted required printing time is smaller in the case when the change processing of the printing conveying speed is skipped than the case when executed.

Description

  The present invention relates to a printing apparatus that performs printing on paper or the like.

  2. Description of the Related Art Conventionally, printing apparatuses that perform printing on a sheet while conveying the sheet are known. In such a printing apparatus, it may be necessary to change various settings for printing according to the type of paper.

  Patent Document 1 discloses a technique for adjusting a head gap based on the thickness of a medium in a printing apparatus that performs printing by ejecting ink from an inkjet head onto a medium being conveyed. In the technique of Patent Document 1, even when the thickness of the medium changes depending on the type of medium to be transported and the current head gap can be transported, the head gap adjustment operation is omitted. Thereby, the printing apparatus of Patent Document 1 shortens the time from the start of printing to the end of printing.

Japanese Patent No. 4590316

  In a printing apparatus that performs printing while transporting paper as described above, the transport speed during printing (print transport speed) may be changed. For example, in a printing apparatus that performs printing by ejecting ink from a inkjet head onto a sheet being conveyed, the printing conveyance speed is slower when the printing resolution is high than when the printing resolution is low. When changing the print transport speed, the print transport speed is changed after the paper being transported is discharged. For this reason, when changing the printing conveyance speed, the processing time for it is consumed.

  In the technique of Patent Document 1, the time required for adjusting the head gap can be omitted, but the above-described processing time is consumed each time the conveyance speed needs to be changed. For this reason, in the printing apparatus of patent document 1, productivity may fall.

  The present invention has been made in view of the above, and an object thereof is to provide a printing apparatus capable of suppressing a decrease in productivity.

  In order to achieve the above object, a first feature of a printing apparatus according to the present invention is a recording unit that feeds a printing medium, and records the printing medium fed from the feeding unit on the printing medium. For each print section that prints with printing material, and for each print medium, set a print transport speed that is set according to the settings related to the recording material application operation in the print section, and print while transporting the print medium at the set print transport speed. A control unit that controls the printing unit to perform printing, and the control unit prints the print conveyance speed when the set print conveyance speed of the next print medium is different from the print conveyance speed set in the printing unit. Even if the set print transport speed of the next print medium is different from the set print transport speed, the next print medium can be printed at the set print transport speed. Acquired print, if any According to the data, the print transport speed changing process is compared with the estimated required printing time including the time required for the print transport speed changing process when the print transport speed changing process is omitted and executed. When the estimated required printing time is shorter than when the process is omitted, the process of changing the print conveyance speed is omitted.

  A second feature of the printing apparatus according to the present invention is that the control unit sets a common set print conveyance speed for each print medium of a print medium group including a plurality of print media including different types of print media. It is possible.

  According to the first feature of the printing apparatus of the present invention, the control unit performs the next operation at the applied print conveyance speed even when the set print conveyance speed of the next print medium is different from the applied print conveyance speed. If the print medium can be printed, the estimated required print time when the print transport speed changing process is omitted and executed according to the acquired print data is compared. The control unit omits the printing conveyance speed changing process when the estimated required printing time is shorter than when the printing conveyance speed changing process is omitted. Thereby, the printing apparatus can shorten the time from the start to the end of printing in a series of printing operations, and can suppress a decrease in productivity.

  According to the second feature of the printing apparatus according to the present invention, by setting a common set print conveyance speed for each print medium in the print medium group, the process of changing the print conveyance speed in the print medium group is omitted. It is possible to suppress the decrease in productivity.

1 is a schematic configuration diagram of a printing apparatus according to a first embodiment. FIG. 2 is a block diagram illustrating a configuration of a control system of the printing apparatus illustrated in FIG. 1. It is a figure which shows an example of the maximum drop number table. It is a figure which shows an example of a printing conveyance speed table. 6 is a flowchart of a process for adjusting the printing conveyance speed of the printing apparatus according to the first embodiment. 10 is a flowchart of processing for adjusting the printing conveyance speed of the printing apparatus according to the second embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Throughout the drawings, the same or equivalent parts and components are denoted by the same or equivalent reference numerals. However, it should be noted that the drawings are schematic and different from the actual ones. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  Further, the embodiment described below exemplifies an apparatus or the like for embodying the technical idea of the present invention, and the technical idea of the present invention is to arrange the components and the like as follows. It is not something specific. The technical idea of the present invention can be variously modified within the scope of the claims.

(First embodiment)
FIG. 1 is a schematic configuration diagram of a printing apparatus according to a first embodiment of the present invention, and FIG. 2 is a block diagram showing a configuration of a control system of the printing apparatus shown in FIG.

  As shown in FIGS. 1 and 2, the printing apparatus 1 according to the first embodiment includes a paper feeding unit 2, a printing unit 3, a communication unit 4, an upper surface transport unit 5, and a paper discharge unit 6. A reversing unit 7, an image reading unit 8, a communication unit 9, an operation panel unit 10, a control unit 11, and a housing 12 that houses or holds each unit.

  In addition, the path | route shown with a thick line in FIG. 1 is a conveyance path | route in which a printing medium is conveyed. Of the transport paths in the printing apparatus 1, the path indicated by the solid line is the normal path RC, the path indicated by the alternate long and short dash line is the reverse path RR, the path indicated by the long dashed line is the discharge path RD, the path indicated by the short dashed line is the communication path RJ, A path indicated by a dotted line is a paper feed path RS. In the following description, upstream and downstream mean upstream and downstream in the transport path. Moreover, the vertical direction and the horizontal direction in the following description shall indicate the vertical direction and the horizontal direction shown in FIG.

  The paper feeding unit 2 feeds paper to the printing unit 3. The paper feed unit 2 is arranged on the most upstream side of the transport path. The paper feed unit 2 includes an external paper feed base 21, an external paper feed roller 22, a plurality of internal paper feed stands 23, a plurality of internal paper feed rollers 24, a plurality of pairs of vertical transport rollers 25, and a registration roller 26. With.

  The external paper feed tray 21 is partly exposed to the outside of the housing 12 and is loaded with paper P that is a print medium.

  The external paper feed roller 22 takes out the paper P one by one from the external paper feed tray 21 and conveys it toward the registration roller 26 along the paper feed path RS. The external paper feed roller 22 is disposed on the upper side of the external paper feed table 21.

  The internal paper feed tray 23 is provided inside the housing 12 and is for loading paper P.

  The internal paper feed roller 24 takes out the paper P one by one from the internal paper feed tray 23 and sends it out to the paper feed path RS. The internal paper feed roller 24 is provided on the upper side of the internal paper feed table 23.

  The vertical conveyance roller 25 is arranged along the paper feed path RS and conveys the paper P taken out from the internal paper feed table 23 toward the registration roller 26.

  The registration roller 26 temporarily stops the paper P conveyed from the external paper feed table 21, the internal paper feed table 23, and the reversing unit 7, and then sends the paper P to the printing unit 3. The registration roller 26 is disposed on the normal route RC in the vicinity of the junction point between the sheet feeding route RS and the reverse route RR.

  The paper feeding unit 2 includes a motor that rotationally drives the external paper feeding roller 22 and the most downstream vertical conveying roller 25, a motor that rotationally drives the internal paper feeding roller 24 and the other vertical conveying roller 25, and a registration roller. And a motor (both not shown) for driving the rotation of the motor 26.

  The printing unit 3 performs printing by ejecting (applying) ink (recording material) to the paper P while transporting the paper P. The printing unit 3 is disposed on the downstream side of the paper feeding unit 2. The printing unit 3 includes a belt conveyance unit 31 and an inkjet head unit 32.

  The belt conveyance unit 31 holds and conveys the paper P conveyed from the registration rollers 26. The belt conveyance unit 31 is disposed on the downstream side of the registration roller 26 and below the inkjet head unit 32. The belt conveyance unit 31 includes a conveyance belt 33, a belt driving roller 34, driven rollers 35 to 37, and a belt motor 38.

  The conveying belt 33 is an annular belt that is stretched around the belt driving roller 34 and the driven rollers 35 to 37. A number of belt holes for attracting and holding the paper P are formed in the transport belt 33. The conveyance belt 33 sucks and holds the paper P by the suction force generated in the belt hole by driving a fan (not shown). The conveyor belt 33 rotates in the clockwise direction in FIG. 1 by driving the belt driving roller 34 to convey the sheet P sucked and held on the conveyance surface (upper surface) in the right direction.

  The belt driving roller 34 and the driven rollers 35 to 37 are for the conveyance belt 33 to be stretched over. The belt driving roller 34 rotates the conveyance belt 33. The driven rollers 35 to 37 are driven by the belt driving roller 34 via the conveying belt 33.

  The belt motor 38 drives the belt driving roller 34 to rotate.

  The inkjet head unit 32 includes a plurality of line-type inkjet heads arranged above the belt conveyance unit 31 and having a plurality of nozzles arranged in a direction orthogonal to the conveyance direction of the paper P. Each inkjet head ejects ink of different colors. The ink jet head unit 32 prints an image by ejecting ink from the ink jet head onto the paper P transported by the belt transport unit 31.

  The communication unit 4 sends the printed paper P to the post-processing device 70. Here, the post-processing device 70 is a device that performs post-processing on the paper P printed by the printing apparatus 1. Post processing includes processing such as offset paper discharge, stapling, and booklet creation. The post-processing device 70 is connected to the downstream side (right side) of the printing apparatus 1. The post-processing device 70 has an introduction roller 71 disposed along the introduction path RF. The introduction roller 71 introduces the paper P from the printing apparatus 1 into the post-processing apparatus 70.

  The communication unit 4 includes a switching unit 41, a communication roller 42, a solenoid (not shown) that drives the switching unit 41, and a motor (not shown) that drives the communication roller 42 to rotate.

  The switching unit 41 switches the transport route of the paper P between the normal route RC and the communication route RJ. The switching unit 41 is disposed at a branch point between the normal route RC and the connection route RJ. The communication path RJ is a path extending rightward from the boundary between the printing unit 3 and the upper surface transport unit 5 toward the post-processing device 70. The downstream end of the communication path RJ is connected to the upstream end of the introduction path RF of the post-processing device 70.

  The contact roller 42 transports the paper P transported from the belt transport unit 31 and sends it to the post-processing device 70. The contact roller 42 is disposed on the downstream side of the switching unit 41 along the contact route RJ.

  The upper surface transport unit 5 transports the paper P transported by the belt transport unit 31 in a U-turn from the right direction to the left direction. The upper surface conveyance unit 5 includes a plurality of pairs of upper surface conveyance rollers 45 and a plurality of motors (not shown) that rotationally drive the plurality of pairs of upper surface conveyance rollers 45.

  The upper surface conveyance roller 45 nips and conveys the paper P. The plurality of pairs of upper surface transport rollers 45 are arranged along a normal path RC between the printing unit 3 and the paper discharge unit 6. The pair of upper surface transport rollers 45 are disposed upstream of the reversing path RR.

  The paper discharge unit 6 discharges and stacks the printed paper P. The paper discharge unit 6 includes a switching unit 51, a paper discharge roller 52, a paper discharge table 53, a solenoid (not shown) that drives the switching unit 51, and a motor (not shown) that rotates the paper discharge roller 52. ).

  The switching unit 51 is disposed at a branch point between the paper discharge path RD and the reversal path RR, and switches the transport path of the paper P between the paper discharge path RD and the reversal path RR.

  The paper discharge roller 52 is disposed between the switching unit 51 and the paper discharge table 53, conveys the paper P conveyed by the upper surface conveyance unit 5 along the paper discharge path RD, and discharges it to the paper discharge table 53. To do.

  The paper discharge tray 53 stacks the paper P conveyed by the paper discharge roller 52.

  The reversing unit 7 reverses the single-side printed paper P and conveys it to the registration roller 26 in order to refeed the single-side printed paper P to the printing unit 3 during double-sided printing. The reversing unit 7 rotates the reversing roller 55, the switchback unit 56, the refeed roller 57, the switching gate 58, a motor (not shown) that rotates the reversing roller 55, and the refeed roller 57. A motor to be driven (not shown).

  The reverse roller 55 temporarily transports the paper P transported by the upper surface transport unit 5 to the switchback unit 56 and then transports it to the refeed roller 57. The reverse roller 55 is disposed on the reverse path RR between the uppermost transport roller 45 on the most downstream side and the carry-in port of the switchback unit 56.

  The switchback portion 56 is a space for the reversing roller 55 to temporarily carry the paper P, and is formed below the paper discharge table 53. The switchback portion 56 is opened in the vicinity of the reversing roller 55 for carrying in the paper P.

  The refeed roller 57 conveys the paper P conveyed by the reversing roller 55 to the registration roller 26. The refeed roller 57 is disposed on the reverse path RR between the reverse roller 55 and the registration roller 26.

  The switching gate 58 guides the paper P conveyed by the upper surface conveyance roller 45 to the reverse roller 55. Further, the switching gate 58 guides the paper P carried out of the switchback unit 56 by the reverse roller 55 to the refeed roller 57. The switching gate 58 is disposed in the vicinity of the center of gravity at the three positions of the uppermost transport roller 45, the reverse roller 55, and the refeed roller 57 on the most downstream side.

  The image reading unit 8 optically reads an image of a document and generates image data. The image reading unit 8 includes a charge coupled device (CCD), a light source, a document table, a document table cover, and a drive motor (none of which is shown) that scans the CCD. The image reading unit 8 generates image data of a document by irradiating a document placed on a document table with light from a light source and reading reflected light from the document with a CCD (Charge Coupled Device).

  The communication unit 9 performs communication processing with an external device such as a PC (personal computer). The communication unit 9 receives print data from an external device.

  The operation panel unit 10 displays various input screens and receives input operations for various settings by the user. The operation panel unit 10 includes operation buttons and a touch panel for a user to perform various input operations such as a liquid crystal display panel that displays various input screens.

  The control unit 11 controls the operation of the entire printing apparatus 1. The control unit 11 includes a storage device such as a CPU, RAM, ROM, and hard disk.

  The control unit 11 stores in advance a maximum drop number table 61 shown in FIG. 3 and a print conveyance speed table 62 shown in FIG.

  The maximum drop number table 61 is a table showing the relationship between the paper type (plain paper, matte paper, etc.) and the maximum drop number. The maximum number of drops is the maximum number of drops of ink that each inkjet head of the inkjet head unit 32 ejects to one pixel. The maximum number of drops is set larger for paper types that are difficult for ink to pass through.

  The print transport speed table 62 is a table showing the relationship among the maximum number of drops, the print resolution, and the print transport speed. The printing conveyance speed is a conveyance speed of the paper P by the belt conveyance unit 31 at the time of printing. The print conveyance speed is set to a speed at which printing can be performed with good image quality according to the maximum number of drops and the print resolution, which are settings related to the ink ejection operation (recording material application operation) in the printing unit 3. The print conveyance speed is set to be slower as the maximum drop number is larger if the print resolution is the same. That is, in FIG. 4, v5 <v3 <v1, v6 <v4 <v2. Further, the print conveyance speed is set to be slower as the print resolution is larger if the maximum number of drops is the same. That is, v2 <v1, v4 <v3, v6 <v5.

  The control unit 11 generates drop data that is data in a format corresponding to printing by the inkjet head unit 32 from the print data. The drop data is data indicating the number of ink drops ejected for each pixel by each inkjet head of the inkjet head unit 32. The control unit 11 refers to the maximum drop number table 61 and generates drop data with the maximum number of drops corresponding to the paper type. Further, the control unit 11 refers to the print conveyance speed table 62 and sets the print conveyance speed according to the maximum number of drops and the print resolution. The print conveyance speed is set for each sheet to be printed.

  The control unit 11 sets the print conveyance speed (setting) for the paper P to be printed next with respect to the print conveyance speed currently set (currently applied) to the belt conveyance unit 31 of the printing unit 3. If the print transport speed is different and the print transport speed needs to be changed, the print transport speed changing process is executed. In the process of changing the printing conveyance speed, the paper P to be printed next is postponed to discharge all the paper P in the printing apparatus 1 to the outside of the apparatus, and the conveyance by the conveyance belt 33 is controlled by the belt motor 38. This process changes the speed. However, even when the printing transport speed needs to be changed, the control unit 11 performs printing transport according to the designated change omission conditions when the next printed paper P can be printed at the currently applied printing transport speed. The speed changing process can be omitted. The change omitting condition is used to determine whether or not the printing conveyance speed changing process can be omitted, and is specified in advance by a user operation, for example.

  Next, the operation of the printing apparatus 1 will be described.

  When the print data to be printed is acquired via the communication unit 9, the control unit 11 generates drop data based on the print data. At this time, the control unit 11 refers to the maximum drop number table 61 based on the paper type information included in the print data and generates drop data with the maximum number of drops corresponding to the paper type. Further, the control unit 11 generates drop data with a resolution corresponding to the information of the print resolution included in the print data. Then, the control unit 11 refers to the print transport speed table 62 and sets the print transport speed corresponding to the maximum number of drops and the print resolution for each sheet to be printed.

  On the other hand, when image data as print data is acquired from the image reading unit 8, the control unit 11 generates drop data from the image data. At this time, the control unit 11 refers to the maximum drop number table 61 based on the sheet type set by the user operation on the operation panel unit 10, and generates drop data with the maximum number of drops corresponding to the sheet type. The image data generated by the image reading unit 8 is data of the print resolution set by the user operation on the operation panel unit 10, and the control unit 11 generates drop data at this resolution. Then, the control unit 11 refers to the print transport speed table 62 and sets the print transport speed corresponding to the maximum number of drops and the print resolution for each sheet to be printed.

  When the print data is acquired and the drop data is generated, the control unit 11 takes out the paper P of the paper type used for printing from either the external paper feed tray 21 or the plurality of internal paper feed trays 23, and directs it toward the registration roller 26. The sheet feeding unit 2 is controlled so as to be conveyed. Further, the control unit 11 drives the belt driving roller 34 of the belt conveying unit 31 to rotate by the belt motor 38.

  When the sheet P hits the registration roller 26, the control unit 11 starts driving the registration roller 26 at a predetermined timing. As a result, the registration roller 26 sends the paper P to the belt conveyance unit 31. The belt conveyance unit 31 holds the paper P sent from the registration rollers 26 on the conveyance belt 33 and conveys it at a set print conveyance speed. The control unit 11 causes the ink jet head unit 32 to eject ink onto the paper P transported by the transport belt 33 to print an image.

  In the case of single-sided printing, the paper P printed by the printing unit 3 is guided to the upper surface conveyance unit 5 by the switching unit 41 of the communication unit 4 and conveyed by the upper surface conveyance unit 5 while being conveyed by the belt conveyance unit 31. . Then, the paper P is guided to the paper discharge roller 52 by the switching unit 51 of the paper discharge unit 6 and discharged to the paper discharge stand 53.

  On the other hand, when the post-processing device 70 is used for single-sided printing, the printed paper P is guided to the communication route RJ by the switching unit 41 of the communication unit 4 while being conveyed by the belt conveyance unit 31. It is sent out to the post-processing device 70 by the roller 42.

  In the case of duplex printing, the paper P on which one side is printed by the printing unit 3 is guided to the upper surface transport unit 5 by the switching unit 41 of the communication unit 4. The sheet P is transported to the switching unit 51 of the paper discharge unit 6 by the upper surface transport unit 5 and is guided to the reversing unit 7 by the switching unit 51. In the reversing unit 7, the paper P is guided to the reversing roller 55 by the switching gate 58, and is carried into the switchback unit 56 by the reversing roller 55. Thereafter, the paper P is unloaded from the switchback unit 56 by the reversing roller 55, guided to the refeed roller 57 by the switching gate 58, and conveyed to the registration roller 26 by the refeed roller 57. The paper P is sent out to the printing unit 3 by the registration roller 26. Here, since the paper P is reversed by the reversing unit 7, the unprinted surface (the other surface) is directed upward, and is printed on the other surface by the inkjet head unit 32. Then, the double-side printed paper P is transported to the paper discharge unit 6 by the upper surface transport unit 5 and discharged to the paper discharge tray 53.

  On the other hand, when the post-processing device 70 is used for double-sided printing, the double-side printed paper P is guided to the communication path RJ by the switching unit 41 of the communication unit 4 while being conveyed by the belt conveyance unit 31. Then, the sheet P is sent out to the post-processing device 70 by the communication roller 42.

  When printing a plurality of sheets, the control unit 11 feeds the paper P continuously from the paper feeding unit 2 at a predetermined interval, and causes the printing unit 3 to perform printing sequentially. During the printing operation, the control unit 11 performs a process of adjusting the print conveyance speed in the belt conveyance unit 31 according to the maximum number of drops for each sheet and the print resolution.

  A process for adjusting the printing conveyance speed will be described. FIG. 5 is a flowchart of a process for adjusting the printing conveyance speed of the printing apparatus 1.

  First, in step S10, the control unit 11 generates drop data from print data to be printed and sets a print conveyance speed.

  Next, in step S20, the control unit 11 determines whether or not printing is currently being performed. Specifically, the control unit 11 determines that printing is being performed when the belt conveyance unit 31 is being driven. Here, when a plurality of sheets are continuously fed to the printing unit 3 at a predetermined interval for printing, the control unit 11 causes the trailing edge of the last sheet of the plurality of sheets to exit the belt conveyance unit 31. The belt conveyance unit 31 continues to be driven.

  When it is determined that printing is not currently being performed (step S20: NO), in step S30, the control unit 11 causes the belt motor 38 to start driving the conveyance belt 33 at the printing conveyance speed set in step S10. Then, the control unit 11 causes the paper feeding unit 2 to feed the paper P. The fed paper P is printed while being conveyed by the printing unit 3.

  When it is determined that printing is currently being performed (step S20: YES), in step S40, the control unit 11 determines whether or not the print conveyance speed set in step S10 is the same as the currently applied print conveyance speed. Judging.

  When it is determined that the print conveyance speed set in step S10 is the same as the currently applied print conveyance speed (step S40: YES), the control unit 11 supplies the paper P by the paper supply unit 2 in step S50. Make paper. The fed paper P is printed while being conveyed by the printing unit 3.

  When it is determined that the print conveyance speed set in step S10 is different from the currently applied print conveyance speed (step S40: NO), in step S60, the control unit 11 determines that the next paper P to be fed (printed) Then, it is determined whether printing is possible without changing the currently applied printing conveyance speed. The paper P to be fed next is printed at the printing conveyance speed set in step S10 by the drop data generated in step S10.

  Here, the print transport speed set for the paper P to be fed next is different from the currently applied print transport speed, but printing is possible without changing the currently applied print transport speed. Is a case where the currently applied print conveyance speed is slower than the print conveyance speed set for the next paper P to be fed. As described above, the printing conveyance speed is set to be slower as the maximum number of drops is larger if the printing resolution is the same, and is set to be slower as the printing resolution is larger if the maximum number of drops is the same. That is, as the number of ink drops ejected in a narrow range is increased, it is necessary to lower the printing conveyance speed. When the printing conveyance speed is increased, it is difficult to accurately eject many ink drops in a narrow range. Therefore, it is difficult to print with good image quality at a printing conveyance speed faster than the set printing conveyance speed. On the other hand, if the printing conveyance speed is slower than the set printing conveyance speed, it is possible to print with good image quality by appropriately controlling the ejection timing. Therefore, when the currently applied print conveyance speed is slower than the print conveyance speed set for the next paper P to be fed, the control unit 11 does not change the currently applied print conveyance speed. Then, it is determined that the paper P to be fed next can be printed.

  If it is determined that the next paper P to be fed cannot be printed without changing the currently applied print conveyance speed (step S60: NO), in step S70, the control unit 11 changes the print conveyance speed. Execute. Specifically, the control unit 11 postpones feeding of the paper P to be printed next, and discharges all the paper P in the printing apparatus 1 to the outside of the apparatus. Then, the control unit 11 controls the belt motor 38 so that the print conveyance speed by the conveyance belt 33 is changed from the currently applied print conveyance speed to the print conveyance speed set for the next paper P to be fed. And change it.

  When the change of the printing conveyance speed is completed, the control unit 11 feeds the next sheet P by the sheet feeding unit 2 in step S50. The fed paper P is printed while being conveyed by the printing unit 3.

  On the other hand, when it is determined in step S60 that the next paper P to be fed can be printed without changing the currently applied printing conveyance speed (step S60: YES), in step S80, the control unit 11 Next, it is determined whether or not the paper P to be fed is for printing print data set for printing in a predetermined printing function. The predetermined printing function is, for example, a booklet printing function corresponding to the booklet creating function by the post-processing device 70. Information indicating such a print function is included in, for example, print data.

  The booklet is bound at the center of the sheet with the cover sheet folded in half and the body sheet folded in half. When the booklet creation function of the post-processing apparatus 70 is used, the printing apparatus 1 performs double-sided printing on one cover sheet, then double-sided printing on one or more body sheets, and sequentially post-processes these. Booklet printing to be sent to the apparatus 70 is performed. In the post-processing device 70, a text sheet is stacked on a cover sheet. The post-processing device 70 creates a booklet by folding the printed material stacked in this way toward the paper for text.

  Generally, a paper type that is thicker than the text sheet and has a larger maximum number of drops is used as the cover sheet of the booklet. For this reason, in the printing apparatus 1, the printing conveyance speed for the cover sheet is set slower than the printing conveyance speed for the body sheet. That is, when the first sheet of text is fed as the next sheet P after the cover sheet is fed, “YES” is determined in step S60.

  After the cover sheet is fed, if the change process to the print conveyance speed corresponding to the body paper is omitted, the body paper is printed with the slow print conveyance speed corresponding to the cover sheet. For this reason, the time required for printing the body paper is longer than that when the printing conveyance speed changing process is performed. On the other hand, when the process of changing the printing conveyance speed is performed, the feeding timing of the first sheet of text is delayed. However, in the booklet, the number of sheets for the text is relatively small. Therefore, even if the printing conveyance speed changing process is omitted, the time required from the start to the end of printing for booklet creation is shorter than when the printing conveyance speed changing process is performed.

  Therefore, when the control unit 11 determines that the paper P to be fed next is to print the print data set for printing in a predetermined printing function such as a booklet printing function (step S80: YES). ) The printing conveyance speed changing process is omitted, and the next paper P is fed by the paper feed unit 2 in step S50. The fed paper P is printed while being conveyed by the printing unit 3. The booklet printing function described above is an example, and other functions may be used.

  The process of the flowchart of FIG. 5 described above is performed for each sheet to be fed and printed. The control unit 11 can acquire print data at any time and accumulate print data for a plurality of sheets.

  As described above, in the first embodiment, even when the print conveyance speed needs to be changed from the currently applied print conveyance speed, the next printed paper P can be printed at the currently applied print conveyance speed. In this case, it is possible to omit the printing conveyance speed changing process according to the designated change omitting condition. As a result, it is possible to reduce the time required to change the printing conveyance speed and reduce the time from the start to the end of printing, and it is possible to suppress a decrease in productivity.

  Specifically, the control unit 11 determines whether or not to omit the print conveyance speed changing process by using information related to the print function based on the print data corresponding to the paper P to be printed next. For example, when the sheet P to be printed next prints print data set for printing in a predetermined printing function such as a booklet printing function, the control unit 11 omits the process of changing the print conveyance speed. . As a result, the printing conveyance speed changing process can be omitted only in a necessary situation, and it can be avoided that the printing is continued at the slow printing conveyance speed due to the omission of the printing conveyance speed changing process and the productivity is lowered.

  Note that change omissible setting information by user setting may be used as the change omission condition. In this case, instead of the processing content of step S80 in FIG. 5 described above, the control unit 11 determines whether or not the change omissible setting is valid. If it is determined that the change omissible setting is valid, the control unit 11 omits the change processing of the print conveyance speed and causes the paper supply unit 2 to feed the next paper P (step S50). If it is determined that the change omissible setting is not valid, the control unit 11 executes a process for changing the printing conveyance speed (step S70), and then feeds the next sheet P by the sheet feeding unit 2 (step S50). .

  Even if it is necessary to change the print transport speed from the currently applied print transport speed, the change omissible setting is that if the next printed paper P can be printed at the currently applied print transport speed, the print transport speed This is a setting for omitting the change process. The change omissible setting can be set in advance, for example, by the user operating the operation panel unit 10.

  For example, when the printing apparatus 1 is placed in a usage situation where a large number of copies are printed on a small number of pages, printing is continued for a long period of time at a slower printing conveyance speed by omitting the printing conveyance speed changing process. This is unlikely to cause a situation where productivity falls. For this reason, omitting the process of changing the printing conveyance speed is effective for shortening the time from the start to the end of printing. In such a case, a decrease in productivity can be suppressed by enabling the change omissible setting in the printing apparatus 1.

  As described above, by using the print function information based on the print data or the change omissible setting information set by the user setting as the change omission condition, it is determined whether to omit the print conveyance speed change process, It is possible to avoid the situation in which the omission of the process for changing the printing conveyance speed causes a decrease in productivity, and to reliably suppress the decrease in productivity. Note that other setting information or the like may be used as the change omission condition.

  Note that the control unit 11 may be able to set a common set print conveyance speed for each sheet of a sheet group including a plurality of sheets that are continuously printed, including different types of sheets. In this case, specifically, the control unit 11 sets the set print transport speed corresponding to the paper type that is the slowest set print transport speed in the paper group to the set print transport speed common to each paper in the paper group. To do. The paper group is composed of a plurality of sheets corresponding to printing units in a predetermined printing function. Examples of the predetermined printing function include a sealed letter preparation printing function performed by the printing apparatus 1 when the post-processing device 70 is a sealed sealing apparatus for preparing a sealed letter. In sealed letter production printing, one envelope sheet corresponding to one sealed letter and one or more content sheets form a sheet group. The envelope is produced by folding a printed content sheet, enclosing the content sheet while being wrapped in a printed envelope sheet, and sealing the envelope sheet.

  Generally, a paper type that is thicker than the content paper and has a large maximum number of drops is used as the envelope paper of the sealed letter. For this reason, the printing conveyance speed for the envelope paper is slower than the printing conveyance speed for the content paper. That is, when the processing of the flowchart of FIG. 5 described above is applied to each sheet of paper to be printed, when the envelope sheet is fed as the next sheet P after the content sheet is fed, in step S60, “ It is determined as “NO”, and the process of changing the printing conveyance speed cannot be omitted. Further, the content paper may be mixed with high-quality paper used for an invitation ticket that is thicker than the envelope paper and has a large maximum number of drops. In this case, when feeding the content sheet during printing, “NO” is determined in step S60, and the process of changing the print conveyance speed cannot be omitted.

  Therefore, in this case, in step S10 of FIG. 5, the control unit 11 determines whether or not it is sealed letter preparation printing when setting the printing conveyance speed. Information indicating sealed letter printing is included in, for example, print data. In the case of sealed letter preparation printing, the control unit 11 sets the set print transport speed corresponding to the paper type that is the slowest set print transport speed in the paper group as the set print transport speed common to each paper in the paper group. . Note that the control unit 11 determines a common set print conveyance speed in the paper group before feeding the first sheet in the paper group for sealed letter printing, and in step S10 for the second and subsequent sheets. A common set print conveyance speed determined before feeding the first sheet is adopted.

  Here, in order to set a print conveyance speed common to each sheet in the sheet group, the control unit 11 spools all print data corresponding to each sheet, and is the slowest among the print conveyance speeds corresponding to each sheet. Printing is performed after the printing conveyance speed is determined. For this reason, the time required for printing the paper group is further increased by the print data spool time. However, in sealed letter preparation printing, the number of content sheets is relatively small. In addition, print data spool time tends to be shortened due to remarkable improvement in network communication speed and electronic device operation speed. Therefore, even if the spool time of the print data is required, the time required from the start to the end of the sealed letter preparation printing is shorter than that when the process for changing the printing conveyance speed is performed.

  As described above, by setting a common set print conveyance speed for each sheet in the sheet group, the process of changing the print conveyance speed in the sheet group can be omitted, and a decrease in productivity can be suppressed.

  The above-described sealed letter preparation printing function is an example, and the present invention is not limited to this. Further, the paper group described above may be set for each print job or for each range designated by the user, instead of one printing unit in the sealed letter preparation printing function or the like.

(Second Embodiment)
Since the printing apparatus according to the second embodiment has the same configuration as that of the printing apparatus 1 according to the first embodiment shown in FIGS. 1 and 2, the printing apparatus according to the second embodiment is also illustrated in FIGS. 2 is used.

  FIG. 6 is a flowchart of a process for adjusting the printing conveyance speed of the printing apparatus 1 according to the second embodiment. In FIG. 6, steps similar to those in the flowchart of FIG. 5 described in the first embodiment are denoted by the same step numbers as in FIG. 5, and description thereof is omitted or simplified.

  As illustrated in FIG. 6, the control unit 11 performs the processes of steps S <b> 10 to S <b> 60 described in the first embodiment.

  If it is determined in step S60 that the next paper P to be fed can be printed without changing the currently applied printing conveyance speed (step S60: YES), in step S110, the control unit 11 performs the first operation. And 2nd prediction time T1, T2 is calculated.

  Specifically, the control unit 11 obtains a print conveyance speed corresponding to each sheet from the acquired print data, and continues printing after the next sheet P to be fed, and the same printing as the next sheet P to be fed. A continuation sheet number that is the number of sheets P for which the conveyance speed is set is obtained.

  Next, the control unit 11 calculates the time required for printing the continuous number of sheets at the currently applied printing conveyance speed as the first predicted time T1. In addition, the control unit 11 calculates, as the second predicted time T2, a time obtained by adding the time required for the process of changing the print transport speed to the time required for printing the continuous number of sheets at the print transport speed for the paper P to be fed next. To do. The first and second predicted times T1 and T2 are calculated using the print conveyance speed, the paper size, and the like.

  Next, in step S120, the control unit 11 determines whether or not the first predicted time T1 is smaller than the second predicted time T2.

  When it is determined that the first predicted time T1 is smaller than the second predicted time T2 (step S120: YES), the control unit 11 omits the printing conveyance speed changing process, and in step S50, the sheet feeding unit 2 The next paper P is fed.

  When it is determined that the first predicted time T1 is equal to or longer than the second predicted time T2 (step S120: NO), the control unit 11 executes a process for changing the printing transport speed in step S70, and then, step S50. Then, the next paper P is fed by the paper feed unit 2.

  As described above, in the second embodiment, the control unit 11 sets the estimated required printing time when the printing conveyance speed changing process corresponding to the acquired print data is omitted and executed as the change omitting condition. The comparison results of the first and second prediction times T1 and T2 are used. When the print conveyance speed change process is executed, the estimated required print time includes the time required for the print conveyance speed change process. Then, the control unit 11 omits the print conveyance speed change process when the estimated required printing time is shorter than when the print conveyance speed change process is omitted (T1 <T2). Thereby, the printing apparatus 1 can reliably shorten the time from the start to the end of printing in a series of printing operations, and can suppress a decrease in productivity.

  In the second embodiment, a common set print conveyance speed may be set for each sheet of the sheet group as in the first embodiment.

(Other embodiments)
As described above, the present invention has been described according to the first and second embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In each of the above-described embodiments, the ink jet printing apparatus has been described. However, the present invention can be applied to other printing apparatuses that perform printing while transporting a print medium.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1 Printing apparatus 2 Paper feed part 3 Printing part 4 Contact part 5 Upper surface conveyance part 6 Paper discharge part 7 Inversion part 8 Image reading part 9 Communication part 10 Operation panel part 11 Control part 31 Belt conveyance part 32 Inkjet head part 38 Belt motor 61 Maximum drop number table 62 Print transport speed table

Claims (2)

A paper feeder for feeding print media;
A printing unit that performs printing by applying a recording material to the printing medium while conveying the printing medium fed from the paper feeding unit;
A control unit configured to set a set print conveyance speed corresponding to the setting relating to the recording material applying operation in the printing unit for each print medium, and to control the printing unit to perform printing while conveying the print medium at the set print conveyance speed; With
The controller is
When the set print transport speed of the next print medium is different from the print transport speed set in the printing unit, the print transport speed changing process is executed,
Even if the set print transport speed of the next print medium is different from the set print transport speed, if the next print medium can be printed at the set print transport speed, the acquired A process for changing the print transport speed by comparing predicted print times including a time required for the print transport speed change process when the print transport speed change process is omitted and executed according to print data. When the estimated required printing time is shorter than when the process is omitted, the printing transport speed changing process is omitted.   2. The control unit can set a common set print conveyance speed for each print medium of a print medium group including a plurality of print media including different types of print media. Printing device.