JP5621665B2 - Image forming apparatus and control program therefor - Google Patents

Description

  The present invention relates to an image forming apparatus having an interrupt function and a control program therefor.

  Some image forming apparatuses perform an interrupt process in which a print job being executed is interrupted and a print job instructed to be interrupted is executed first. When interrupt processing is performed, processing of the print job being executed (interrupted print job) is interrupted until processing of the interrupted print job is completed. Therefore, even when the remaining time until the completion of processing of the print job being executed is very short compared with the time required for processing of the interrupted print job, the processing of the print job being executed is interrupted. Therefore, the completion time of the print job being executed is delayed more than necessary, and the user waits for a long time. As a technique for solving this problem, for example, techniques described in Patent Documents 1 and 2 below are known.

  In the technique described in Patent Document 1, when the remaining data amount until the completion of processing of the print job being executed is larger than the total data amount of the print job instructed to interrupt, it is determined that interrupt processing is performed. If it is small, the user is prevented from waiting for a long time by determining that the interrupt processing is not performed.

  In the technique described in Patent Document 2, when the remaining time until completion of the print job being executed is shorter than the specified time, or when the remaining page number is shorter than the specified page number, the interrupt process By determining not to perform the operation, the user is prevented from waiting for a long time.

Japanese Patent Laid-Open No. 10-111770 JP 2003-122526 A

  However, the techniques described in Patent Documents 1 and 2 do not use the determination regarding the type of print mode in determining whether to perform interrupt processing. Therefore, when a print job interruption in a print mode different from the print mode of the print job being executed is instructed and the time required for changing the print mode is relatively long, the determination of whether or not to perform interruption processing is accurate. The user may have to wait for a long time, or the throughput for executing the entire print job may be reduced.

  Therefore, an object of the present invention is to reduce the possibility that the user will wait for a long time even when an interrupt of a print job of a print mode different from the print mode of the print job being executed is instructed, and Another object of the present invention is to provide an image forming apparatus capable of improving the throughput for executing the entire print job.

  In order to solve the above-described problems, an image forming apparatus according to the present invention is an image forming apparatus having a plurality of print modes, a job execution unit that executes a print job related to image formation on a recording medium, and the job execution With respect to the first print job being executed by the means, a remaining time calculating means for calculating a remaining time until the first print job is completed, a print mode of the first print job, and execution of the print job Transition from the first print job to the second print job, and from the second print job to the first print job, based on the print mode of the second print job for which an interrupt instruction has been issued Mode change time indexing means for determining the print mode change time associated with the transition to, and the remaining time calculated by the remaining time calculating means is at least the Interrupt determination for determining that interrupt processing for interrupting the first print job and executing the second print job is performed when the change time is longer than the change time calculated by the mode change time indexing means. And an interrupt control unit that controls the job execution unit so that the first print job is interrupted and the second print job is executed when the interrupt determination unit determines to perform the interrupt processing. And an insertion control means.

The control program of the image forming apparatus of the present invention, have a plurality print modes including a monochrome mode and color mode, discharge color discharge ports are formed for ejecting the recording liquid of the color on the recording medium A color discharge head having a surface, a black discharge surface having a black discharge surface in which a discharge port for discharging a black recording liquid is formed on a recording medium, and the color discharge surface of the color discharge head A cap for moving the color cap between a color capping position that surrounds the color ejection surface and a color uncapping position that exposes the color ejection surface and means, an image forming apparatus equipped with the color and for black ejection head, and to control said cap driving means, A job execution unit that executes a print job related to image formation on a recording medium, and a remaining time for calculating a remaining time until the first print job is completed with respect to the first print job executed by the job execution unit Based on the time calculation means, the print mode of the first print job, and the print mode of the second print job instructed to interrupt execution of the print job, the first print job to the second print job. A transition to a print job, a mode change time indexing means for determining a change time of a print mode associated with the transition from the second print job to the first print job, and the remaining time calculated by the remaining time calculation means The first print job is interrupted when the time is at least larger than the change time determined by the mode change time indexing means. Interrupt determining means for determining whether to perform interrupt processing for executing the second print job, and interrupting the first print job when the interrupt determining means determines to perform the interrupt processing. So that the color and black ejection heads and the cap driving means are controlled so that the second print job is executed , and the job execution means has the print mode in the monochrome mode. In the mode, the cap driving means is controlled so that the color cap is positioned at the color capping position, the black recording liquid is discharged from the black discharge surface, and the color discharge surface is discharged from the color discharge surface. The color and black discharge heads are controlled so that the discharge of the color recording liquid is prohibited, and the print mode is the color. In the color mode, the cap driving means is controlled so that the color cap is located at the color uncapping position, and the black recording liquid is transferred from the black discharge surface to the color discharge surface. The color and black discharge heads are controlled to discharge color recording liquids, respectively, and the mode change time indexing means includes a print mode for the first print job, a print mode for the second print job, However, when the monochrome mode and the color mode are different from each other, the time required to reciprocate the color cap between the color capping position and the color uncapping position is changed. It is included in time .

  According to the image forming apparatus and the control program for the image forming apparatus, the interrupt process is not performed when the remaining time of the first print job being executed is equal to or shorter than the print mode change time. Since the user of the print job can be prevented from waiting more than necessary, and the number of times of changing the print mode can be reduced, the throughput for executing the entire print job can be improved.

  In the image forming apparatus of the present invention, the interrupt determination unit performs the interrupt process only when the priority of the first print job and the priority of the second print job are the same. You may judge. According to the above configuration, a print job having a high priority can be executed with priority.

  The image forming apparatus according to the present invention further includes storage means for storing at least one of the interruption time of the first print job interrupted by the interrupt processing and the number of interruptions. The determination unit may determine to perform the interrupt processing when the interruption time of the first print job stored in the storage unit is less than a predetermined time or the number of interruptions is less than a predetermined number. . According to the above configuration, it is possible to prevent the user of the first print job from waiting for a long time.

  The image forming apparatus of the present invention further includes an interrupt job execution time calculation unit that calculates an execution time of the second print job, and the interrupt determination unit is calculated by the remaining time calculation unit. The calculated remaining time is greater than the sum of the change time calculated by the mode change time indexing unit and the execution time of the second print job calculated by the interrupt job execution time calculating unit. If it is larger, it may be determined to perform the interrupt processing. According to the above configuration, the interrupt process is not performed when the remaining time of the first print job being executed is equal to or less than the sum of the execution time of the second print job and the print mode change time. Therefore, it is possible to prevent the user of the first print job from waiting more than necessary, and to reduce the number of times the print mode is changed, thereby improving the throughput for executing the entire print job. it can.

  In the image forming apparatus according to the aspect of the invention, the interrupt determination unit may perform the interrupt when the execution time of the second print job calculated by the interrupt job execution time calculation unit is at least less than a predetermined time. You may judge performing a process. According to the above configuration, it is possible to prevent the user of the first print job from waiting for a long time.

In the image forming apparatus according to any one of the first to third aspects of the present invention, the job execution unit includes a color discharge surface on which a discharge port for discharging a color recording liquid is formed on a recording medium. A black discharge head having a black discharge surface in which a discharge port for discharging black recording liquid to a recording medium is formed, and the color discharge surface of the color discharge head can be surrounded A cap for color, and a cap driving means for moving the color cap between a color capping position that surrounds the color ejection surface and a color uncapping position that exposes the color ejection surface; Color and black discharge heads, and control means for controlling the cap driving means. When the print mode is the monochrome mode, the control means controls the cap driving means so that the color cap is positioned at the color capping position. And controlling the color and black discharge heads such that the black recording liquid is discharged from the black discharge surface, and discharge of the color recording liquid from the color discharge surface is prohibited, When the printing mode is the color mode, the control unit controls the cap driving unit so that the color cap is located at the color uncapping position, and the black recording is performed from the black discharge surface. The color recording liquid is discharged so that the color recording liquid is discharged from the color discharge surface. The black discharge head is controlled, and the mode change time indexing unit is configured such that the print mode of the first print job and the print mode of the second print job are different from each other in the monochrome mode and the color mode. in case you are, the time accompanying the color cap to reciprocate between the uncapped position for color and the color for the capping position, are included in the change time. According to the above configuration, in the monochrome mode, since the color ejection surface is surrounded by the color cap, it is possible to suppress drying of the recording liquid near the ejection port of the color ejection head. In addition, since the time required to move the color cap when changing the print mode between the monochrome mode and the color mode is included in the change time of the print mode, it is more accurate to determine whether to perform interrupt processing. As a result, the possibility that the user will wait for a long time can be reduced, and the throughput for executing the entire print job can be improved.

In the image forming apparatus according to the second aspect of the present invention, the image forming apparatus further includes an interrupt job execution time calculating unit that calculates an execution time of the second print job. When the print mode is the color mode and the print mode of the second print job is the monochrome mode, the execution time of the second print job calculated by the interrupt job execution time calculation unit When the color recording liquid needs to be forcibly ejected from the ejection port of the color ejection head and the non-ejection limit time is less than the time limit, the mode change time indexing means is configured to remove the color cap from the color cap. The time required to reciprocate between the position and the color uncapping position is not included in the change time, and the change time is Ri out, the job execution means is in when executing the second print job is also the color cap is controlled by said control means said cap driving means so as to be positioned in the uncapping position for the color. According to the above configuration, when the execution time of the second print job is equal to or shorter than the non-ejection limit time, the second print job can be executed without moving the color cap. The time required for the mode change can be reduced. As a result, the user can be prevented from waiting more than necessary, and the throughput for executing the entire print job can be improved.

The image forming apparatus according to a third aspect of the present invention further includes an interrupt job execution time calculating unit that calculates an execution time of the second print job, and the image forming apparatus includes: When the print mode is the color mode and the print mode of the second print job is the monochrome mode, the execution time of the second print job calculated by the interrupt job execution time calculation unit When the non-ejection limit time for which the color recording liquid needs to be forcibly ejected from the ejection port of the color ejection head and the interrupt determination means determines to perform the interrupt processing, the job The execution unit determines whether or not to position the color cap at the color uncapping position even when executing the second print job. And was determined by the choice of the user, controlled by said control means said cap driving means on the basis of this determination result. According to the above configuration, image formation is performed by a method in which the consumption amount of the recording liquid is increased but the waiting time of the user is shortened, or an image is formed by a method in which the consumption amount of the recording liquid is small but the waiting time of the user is increased. The user can select whether to perform the formation.

In the image forming apparatus according to the third aspect of the present invention, the job execution unit controls the cap driving unit with the control unit so that the color cap is located at the color uncapping position. When the second print job is being executed, the control unit of the job execution unit causes the color recording liquid to be forcibly discharged from the discharge port of the color discharge head. The head may be controlled. According to the above configuration, the recording liquid that has been thickened by drying near the discharge port of the color discharge head can be forcibly discharged during monochrome printing, so that the user has to wait more than necessary. Can be prevented, and the throughput of executing the entire print job can be improved.

In the image forming apparatus according to the fourth aspect of the present invention, the job execution unit includes a transport unit that transports the recording medium in the transport direction and an ejection port for ejecting the black recording liquid onto the recording medium. A black discharge head having a black discharge surface, and an upstream side of the black discharge head in the transport direction, and acts on the black recording liquid to aggregate the components in the black recording liquid Alternatively, a processing liquid discharge head having a processing liquid discharge surface in which a plurality of discharge ports for discharging a processing liquid to be deposited is formed, and a processing liquid discharge head capable of surrounding the processing liquid discharge surface of the processing liquid discharge head. A cap, a treatment liquid capping position that surrounds the treatment liquid ejection surface, and a treatment liquid uncapping position that exposes the treatment liquid ejection surface. And a control unit for controlling the cap driving means. The plurality of printing modes include a low quality mode and a high quality. And when the printing mode is the low quality mode, the control means controls the cap driving means so that the processing liquid cap is positioned at the processing liquid capping position; and The black recording liquid is ejected from the black ejection surface, and the black and processing liquid ejection heads are controlled so that ejection of the processing liquid from the processing liquid ejection surface is prohibited, and the printing is performed. When the mode is the high quality mode, the control means causes the cap so that the processing liquid cap is located at the processing liquid uncapping position. And controlling the black and processing liquid discharge heads such that the black recording liquid is discharged from the black discharge surface and the processing liquid is discharged from the processing liquid discharge surface. The mode change time indexing unit is configured such that when the print mode of the first print job and the print mode of the second print job are different from each other in the low quality mode and the high quality mode, the capping treatment liquid time associated to reciprocate between said processing liquid uncapping position and the capping position for the processing liquid, it is included in the change time. According to the above configuration, in the case of the low quality mode, the processing liquid discharge surface is surrounded by the processing liquid cap, so that drying of the processing liquid near the discharge port of the processing liquid discharge head is suppressed. Can do. In addition, since the time required for moving the processing liquid cap when changing the print mode between the low quality mode and the high quality mode is included in the print mode change time, it is determined whether or not to perform interrupt processing. As a result, the possibility that the user will wait for a long time can be reduced, and the throughput for executing the entire print job can be improved.

Further, in the image forming apparatus according to the fifth aspect of the present invention, the job execution unit supports the recording medium and an ejection head having an ejection surface in which an ejection port for ejecting the recording liquid to the recording medium is formed. A conveying means for conveying the recording medium so that the recording medium supported by the supporting surface passes through a position facing the ejection surface, the ejection head, the first position, and the support A distance adjusting means capable of adjusting a distance between the ejection surface of the ejection head and the support surface by moving between a second position having a distance to the surface larger than the first position. The plurality of print modes include a thin paper mode for forming an image on a first recording medium and a thick paper mode for forming an image on a second recording medium thicker than the first recording medium. And the interval adjusting means has the printing mode. When the thin paper mode is selected, the discharge head is positioned at the first position, and when the print mode is the thick paper mode, the discharge head is positioned at the second position. When the printing mode of the first print job and the printing mode of the second print job are different from each other in the thin paper mode and the thick paper mode, the ejecting unit moves the ejection head to the first print job. position and the time involved to reciprocate between the second position and is included in the change time. According to the above configuration, since the interval between the support surface and the ejection surface of the ejection head is changed according to the thickness of the recording medium, a high-quality image can be formed on the recording medium. In addition, since the time required for moving the processing liquid cap when changing the print mode between the thin paper mode and the thick paper mode is included in the change time of the print mode, it is further determined whether or not to perform interrupt processing. Since it can be performed accurately, the possibility that the user will wait for a long time can be reduced, and the throughput for executing the entire print job can be improved.

  Even when an instruction is issued to interrupt a print job in a print mode different from the print mode of the print job being executed, the possibility that the user will wait for a long time can be reduced, and the throughput for executing the entire print job Can be improved.

1 is a schematic side view showing an overall configuration of an inkjet printer according to an embodiment of the present invention. It is explanatory drawing explaining the space | interval of the discharge surface of an inkjet head and a precoat head, and the support surface of a conveyance belt. (A) It is a top view of a cap mechanism. (B) It is sectional drawing regarding the VB-VB line | wire shown to Fig.3 (a). It is a figure explaining capping of a cap mechanism. It is explanatory drawing explaining the capping operation | movement of a cap mechanism. It is a block diagram which shows schematic structure of the control part shown in FIG. It is a flowchart figure which shows the printing operation of the inkjet printer shown in FIG. FIG. 8 is a flowchart of the interrupt determination process shown in FIG. It is a flowchart figure of the mode change time index process shown in FIG. FIG. 8 is a flowchart of the interrupt job execution process shown in FIG.

  Hereinafter, as a preferred embodiment of the present invention, an image forming apparatus is applied to an ink jet printer and will be described with reference to the drawings.

  As shown in FIG. 1, the inkjet printer 101 according to the present embodiment includes a substantially rectangular parallelepiped casing 101 a. In the housing 101 a, a transport mechanism (transport means) 16 that transports the paper (recording medium) P in the transport direction (the direction from the left to the right in FIG. 1), and the paper P transported by the transport mechanism 16. In addition, four inkjet heads 1 (discharge heads) that discharge ink droplets of ink (recording liquid) and a precoat head 2 (process) that discharges droplets of a precoat liquid (processing liquid) that aggregates or deposits the pigment component of the ink. (Liquid discharge head), a head lifting mechanism (interval adjusting means) 33, a cap mechanism 34 (see FIG. 3), a controller 100 for controlling the entire inkjet printer 101, and a touch panel 90 (see FIG. 6) are provided. ing. The inkjet head 1 includes an inkjet 1A (black ejection head) that ejects ink droplets of black (K) ink, and ink droplets of cyan (C), magenta (M), and yellow (Y) color inks. There are three inkjet heads 1B (color ejection heads) that respectively eject the ink.

  In the present embodiment, the sub-scanning direction is a direction parallel to the transport direction when the paper P is transported by the transport mechanism 16, and the main scanning direction is a direction orthogonal to the sub-scanning direction and along the horizontal plane. Direction.

  In this embodiment, the inkjet printer 101 has a monochrome mode and a color mode related to printing, a low quality mode and a high quality mode related to quality, and a thin paper mode and a thick paper mode related to a recording medium as print modes. The monochrome mode is a print mode in which a monochrome image is formed on the paper P using only black ink, and the color mode is a color image on the paper P using black, cyan, magenta, and yellow ink. This is a printing mode to be formed. The low quality mode is a printing mode in which an image is formed on the paper P using only ink. The high quality mode is a high quality image in which a high quality image is formed on the paper P using a precoat liquid and ink. Print mode. The thin paper mode is a printing mode in which an image is formed on the plain paper P1 (first recording medium). The thick paper mode is a thick paper P2 (second paper) thicker than the plain paper P1 such as a postcard or an envelope. This is a printing mode for forming an image on a recording medium.

  A tank unit 101c is provided in the housing 101a. Inside the tank unit 101c, one ink tank 20a storing black ink, three ink tanks 20b storing magenta, cyan, and yellow inks respectively, and one precoat storing a precoat liquid are stored. A liquid tank 20c is stored. The ink tanks 20a and 20b and the precoat liquid tank 20c are detachably attached to the tank unit 101c.

  The ink stored in the ink tanks 20a and 20b is supplied to the corresponding inkjet heads 1A and 1B via ink tubes (not shown). Similarly, the precoat liquid stored in the precoat liquid tank 20c is supplied to the precoat head 2 via a precoat tube (not shown).

  As the precoat liquid, a precoat liquid for aggregating pigment pigments is generally used for pigment ink, and a precoat liquid for depositing dye pigments is used for dye ink. The material of the precoat liquid can be appropriately selected from a liquid containing a polyvalent metal salt such as a cationic polymer or a magnesium salt. When the ink lands on the region of the paper P to which such a precoat liquid has been applied in advance, the polyvalent metal salt or the like acts on the dye or pigment that is the colorant of the ink, and the insoluble or hardly soluble metal composite or the like aggregates. Formed by precipitation. Note that the precoat liquid may have a function of improving the color density of the ink.

  In addition, the inkjet printer 101 is provided with a paper feed unit 101b, a transport mechanism 16 disposed above the paper feed unit 101b, and a paper discharge unit 15 through which the paper P is discharged, along the paper P transport path. ing. Further, the inkjet printer 101 is provided with a manual feed tray 37 that protrudes leftward from the left side surface in FIG. 1 of the housing 101a and is slightly inclined upward. The manual feed tray 37 is detachably provided on the housing 101 a through the opening 102.

  The paper feed unit 101b is detachably arranged with respect to the housing 101a, and includes a paper feed tray 11 and a paper feed roller 12. The paper feed tray 11 has a box shape opened upward, and stores a plurality of paper sheets P in a stacked state. The paper feed roller 12 sends out the paper P located on the uppermost side of the paper feed tray 11 to the transport mechanism 16 under the control of the controller 100. The fed paper P is sent to the transport mechanism 16 by the feed roller pair 14 along the guides 13a and 13b. In the present embodiment, plain paper P1 is stored in the paper feed tray 11 as the paper P.

  Near the end of the manual feed tray 37 in the housing 101 a, a manual tray paper feed roller 36 that feeds the paper P held on the manual feed tray 37 to the transport mechanism 16 is disposed. The manual feed tray paper feed roller 36 sends out the paper P located on the uppermost side of the manual feed tray 37 to the transport mechanism 16 under the control of the controller 100. In the present embodiment, the manual feed tray 37 stores thick paper P2 as the paper P.

  The transport mechanism 16 includes two belt rollers 6 and 7, a transport belt 8, a tension roller 10, and a platen 18. The conveyor belt 8 is an endless belt wound between the belt rollers 6 and 7, and tension is applied by the tension roller 10. The belt roller 7 is a driving roller that is driven to rotate clockwise in FIG. 1 by a motor (not shown), and causes the conveyor belt 8 to travel. The belt roller 6 is a driven roller that rotates as the conveyor belt 8 travels. The outer peripheral surface of the conveyor belt 8 is a support surface 8a on which a weakly adhesive silicon layer is formed, and supports the paper P. The paper P placed on the support surface 8a of the transport belt 8 is transported to the right in FIG.

  The peeling plate 5 is disposed on the downstream side in the transport direction of the paper P in the transport mechanism 16. The sheet P transported in the transport direction by the transport mechanism 16 is sequentially peeled off from the support surface 8a of the transport belt 8 by the stripping plate 5 after sequentially passing below the precoat head 2 and the four inkjet heads 1A and 1B. The paper P peeled off by the peeling plate 5 is conveyed upward by the two pairs of feed rollers 28 along the guides 29a and 29b, and from the discharge port 22 formed in the upper part of the housing 101a to the paper discharge unit 15. Discharged. The platen 18 is disposed so as to face the four inkjet heads 1A and 1B and the precoat head 2, and supports the upper loop of the conveyor belt 8 from the inside.

  The four inkjet heads 1A and 1B and the precoat head 2 have the same structure, extend along the main scanning direction, and are arranged in parallel and at equal intervals in the sub-scanning direction. The lower surfaces of the inkjet heads 1A and 1B are ejection surfaces 1a and 1b on which a plurality of ejection ports arranged at intervals of 600 dpi are formed along the main scanning direction. That is, the ink jet printer 101 is a line type color ink jet printer in which a plurality of ejection openings for ejecting ink droplets are arranged in the main scanning direction. Similarly, the lower surface of the precoat head 2 is a discharge surface 2a on which a plurality of discharge ports arranged at intervals of 600 dpi along the main scanning direction are formed.

  Of the four inkjet heads 1A and 1B, black ink droplets are ejected from the inkjet head 1A disposed on the most upstream side in the transport direction. From the remaining three inkjet heads 1B, ink droplets of a color other than black (that is, magenta, cyan, yellow) are ejected. The precoat head 2 from which the precoat liquid is discharged is disposed on the upstream side in the transport direction of the four inkjet heads 1A and 1B.

  The support surface 8a of the upper loop of the conveyor belt 8 and the discharge surfaces 1a, 1b, 2a are parallel to each other while facing each other. When the paper P conveyed by the conveyance belt 8 passes just below the precoat head 2, the precoat liquid is applied from the precoat head 2 so that the precoat liquid is applied to the area where the image is formed on the upper surface of the paper P. A droplet is ejected. Thereafter, when the paper P passes immediately below the four inkjet heads 1A and 1B, ink droplets of the respective colors are sequentially applied from the inkjet heads 1A and 1B to the area where the precoat liquid is applied on the upper surface of the paper P. Discharged. As a result, a desired monochrome image or color image is formed on the paper P. At this time, when the ink droplets land on the precoat liquid applied on the paper P, the precoat liquid aggregates or precipitates the pigment component of the ink droplets, so that ink bleeding on the paper P is prevented and a high-quality image is formed. Will be formed.

  The head lifting mechanism 33 is a lifting device 83 (see FIG. 6) that can lift and lower the frames 35a, 35b, and 35c that support the inkjet heads 1A and 1B and the precoat head 2 and the frames 35a, 35b, and 35c, respectively. And have. As the lifting device 83, for example, a rack, a pinion, a solenoid, or the like can be used.

  As shown in FIG. 1, the precoat head 2 is fixed to a frame 35a. The black inkjet head 1A that discharges black ink droplets is fixed to a frame 35b. The three color inkjet heads 1B that eject ink droplets of yellow, cyan, and magenta are fixed to a frame 35c.

  The elevating device 83 can move the four inkjet heads 1 and the precoat head 2 up and down by moving the frames 35a, 35b, and 35c up and down. As a result, the intervals between the support surface 8a of the conveyor belt 8 and the ejection surfaces 1a, 1b, 2a of the four inkjet heads 1 and the precoat head 2 are adjusted and suitable for image formation according to the thickness of the paper P. A predetermined interval can be formed. Specifically, the lifting device 83 lifts and lowers the frames 35a, 35b, and 35c to move the four inkjet heads 1 and the precoat head 2 to the “first position” (see FIG. 2A). The “second position” (in FIG. 2), the distance between the support surface 8a of the conveyor belt 8 and the discharge surfaces 1a, 1b, 2a of the four inkjet heads 1 and the precoat head 2 is larger than the distance between the “first positions”. (See (b)). Here, the “first position” is a position set at an interval d1 suitable for image formation on the plain paper P1. The “second position” is a position set at an interval d2 suitable for image formation on the thick paper P2, and the interval d2 is set larger than the interval d1.

  As shown in FIG. 3, the cap mechanism 34 includes a treatment liquid cap 71, a black cap 72, three color caps 73, a tray 76 that supports the cap 71, and a tray that supports the cap 72. 77, a tray 78 for supporting the three caps 73, and a tray moving device 84 (see FIG. 6) capable of independently moving the three trays 76 to 78 in the main scanning direction and the vertical direction. The caps 71 to 73 are elastic members having a recess 74. The side wall of the recess 74 has a tapered surface that is inclined outward as the inner wall surface approaches the tip. The tray moving device 84 moves the trays 76 to 78 in the main scanning direction and the up and down direction, thereby enclosing the caps 71 to 73 around the ejection surfaces 1a, 1b, and 2a (see FIG. 5C). ) And an “uncapping position” (see FIG. 5A) that exposes the ejection surfaces 1a, 1b, and 2a.

  Specifically, the “capping position” is a position where the tips of the concave portions 74 of the caps 71 to 73 come into contact with the corresponding ejection surfaces 1a, 1b, 2a. The “uncapping position” is a position that is displaced in the main scanning direction with respect to the heads 1 and 2 and does not face the ejection surfaces 1a, 1b, and 2a.

  When the printing mode is the monochrome mode, as shown in FIG. 4A, the cap 73 is positioned at the “capping position”, and the ejection surface 1 b is surrounded by the cap 73. When the printing mode is the low quality mode, the cap 71 is positioned at the “capping position” as shown in FIG. 4B, and the ejection surface 2 a is surrounded by the cap 71. Further, when the ink jet printer 101 is in a standby state (when image formation is not being performed), as shown in FIG. 4C, the caps 71 to 73 are positioned at the “capping position” and all the ejection surfaces are located. 1a, 1b, 2a is surrounded by caps 71-73. Thus, by surrounding the ejection surfaces 1a, 1b, and 2a with the caps 71 to 73, it is possible to suppress drying of the ink liquid and the precoat liquid in the vicinity of the ejection ports of the heads 1 and 2.

  Next, the capping operation will be described with reference to FIG. In the following, for convenience of explanation, only the capping operation of the cap 73 will be described, but the capping operation of the cap 71 and the cap 72 is the same operation.

  As shown in FIG. 5A, when the printing mode is the color mode, the cap 73 is displaced in the main scanning direction with respect to the inkjet head 1B and is positioned at an “uncapping position” that does not face the ejection surface 1b. Has been. When the capping operation is started, the head 1B is moved upward, and the interval between the support surface 8a and the discharge surface 1b is widened. In this state, the tips of the recesses 74 of the caps 71 to 73 are below the discharge surface 2a. Next, as shown in FIG. 5B, the cap 73 is moved in the main scanning direction (rightward in FIG. 5) by the tray moving device 84, and the cap 73 is opposed to the corresponding ejection surface 1 b. Located in. Thereafter, as shown in FIG. 5C, when the cap 73 is moved upward by the tray moving device 84, the cap 73 is positioned at a “capping position” surrounding the ejection surface 1b. The uncapping operation is the reverse of the above-described operation procedure.

  Next, the controller 100 will be described with reference to FIG. The controller 100 includes a CPU (Central Processing Unit), a program executed by the CPU and a non-volatile memory that stores data used for these programs in a rewritable manner, and a RAM (Random Access) that temporarily stores data when the program is executed. Memory). Each functional unit constituting the controller 100 is constructed by cooperation of these hardware and software in the nonvolatile memory. As shown in FIG. 3, the controller 100 controls the entire inkjet printer 101, and includes an execution job storage unit 130, a job management unit 131, a flag storage unit 132, a remaining time calculation unit 133, and an interrupt job execution time calculation. Unit 134, mode change time index unit 135, interrupt determination unit 136, job control unit 137, interrupt control unit 138, and input / output control unit 139.

  The execution job storage unit 130 stores (registers) a print job to be executed by the job control unit 137. The print job includes image data of an image formed (printed) on the paper P, information on the priority, and information on the print mode. The image data includes black, cyan, and magenta for each of a plurality of pixels (unit areas) corresponding to the resolution of an image partitioned on the paper P along the transport direction and the main scanning direction (orthogonal direction orthogonal to the transport direction). , And a density value related to each yellow ink and precoat liquid. This density value is quantized into four values corresponding to no discharge, small droplet, medium droplet, and large droplet. The information regarding the priority indicates the priority order for executing the print job. The print job includes a print mode related to printing in either the color mode or the monochrome mode, a print mode related to the quality of either the low quality mode or the high quality mode, and either the thin paper mode or the thick paper mode. The information regarding the printing mode regarding the recording medium is included.

  The job management unit 131 generates a print job each time a print request is received from an external device, and registers the print job in a queue (queue) in the order of generation (the order in which the print is requested). However, the job management unit 131 sorts and registers print jobs with high priority so that they are arranged at the head of the queue rather than print jobs with low priority. When the print job being executed by the job control unit 137 is completed, the job management unit 131 registers the print job at the head of the queue in the execution job storage unit 130. Further, the job management unit 131 stores, for each standby job, the interruption time (hereinafter referred to as interruption interruption time) interrupted by interruption processing and the number of interruptions (hereinafter referred to as interruption interruption number). Note that the standby job refers to a print job that is registered in the queue of the job management unit 131 and is waiting for execution of its own job.

  In the following description, a print job (interrupt print job) for which an interrupt instruction relating to execution of a print job has been issued is print job B, and when this print job B is generated by the job management unit 131, the job control unit 137 The print job being executed is referred to as print job A.

  The flag storage unit 132 displays on the touch panel 90 an uncapping flag indicating whether or not to place the color cap 73 at the “uncapping position” and a selection screen regarding the arrangement of the color cap 73. The display flag to indicate is stored. The uncapping flag indicates that the color cap 73 is positioned at the “uncapping position” when in the on state, and is not positioned (positioned at the capping position) when in the off state. The display flag indicates that a selection screen related to the arrangement of the color cap 73 is displayed when the display flag is in the on state, and is not displayed when the display flag is in the off state.

  Further, the flag storage unit 132 stores the interrupt specified interrupt time, the interrupt specified interrupt count, and the interrupt job specified execution time. The interrupt prescribed interruption time defines the minimum interruption interruption time for prohibiting interruption processing for the print job A. The interrupt specified interrupt count specifies the minimum interrupt interrupt count for prohibiting interrupt processing for the print job A. The interrupt job specified execution time specifies the minimum execution time of print job B that prohibits interrupt processing for print job A. These interrupt specified interruption time, interrupt specified interrupt count, and interrupt job specified execution time may be set in advance in the inkjet printer 101, may be set by user input, or all print jobs. May be set uniformly, or may be set for each print job.

  The remaining time calculation unit 133 calculates the remaining time until the print job A is completed with respect to the print job A being executed by the job control unit 137. The interrupt job execution time calculation unit 134 calculates the execution time of the print job B.

  Based on the print mode of print job A executed by the job control unit 137 and the print mode of print job B, the mode change time indexing unit 135 changes the print job A to the print job B, and the print job. The print mode change time associated with the transition from B to print job B is determined. Specifically, when the print mode of the print job A and the print mode of the print job B are different between the monochrome mode and the color mode, the color cap 73 is set to “capping position” and “uncapping position”. The time required for the reciprocating movement (time required for the capping operation and the uncapping operation) is included in the print mode change time. Further, when the print mode of the print job A and the print mode of the print job B are different between the low quality mode and the high quality mode, the cap 71 for the processing liquid is set to the “capping position” and the “uncapping position”. ”Is included in the print mode change time. When the print mode of print job A and the print mode of print job B are different between the thin paper mode and the thick paper mode, the heads 1 and 2 are moved to the “first position” and the “second position”. The time required for reciprocating between the printing mode and the print mode is included in the printing mode change time.

  The interrupt determination unit 136 determines whether or not to perform an interrupt process for executing the print job B by interrupting the print job A currently being executed by the job control unit 137. Specifically, the remaining time until the completion of the print job A calculated by the remaining time calculating unit 133 is the print mode change time calculated by the mode change time indexing unit 135 and the interrupt job execution time calculating unit. If it is larger than the sum of the execution times of the print job B calculated in 134, it is determined that an interrupt process is to be performed.

  The job control unit 137 includes a conveyance control unit 151, a cap control unit 152, an interval adjustment unit 153, and a head control unit 154, and executes a print job related to image formation on the paper P. The conveyance control unit 151 controls the paper feed roller 12, each pair of feed rollers 14 and 28, the manual feed tray paper feed roller 36, and the conveyance belt 8. When the print mode of the print job stored in the execution job storage unit 130 is the thin paper mode, the conveyance control unit 151 sends the plain paper P1 that is at the top of the paper feed tray 11 to the conveyance mechanism 16. In this manner, the paper feed roller 12 is controlled. On the other hand, when the print mode of the print job stored in the execution job storage unit 130 is the thick paper mode, the thick paper P2 located on the uppermost side of the manual feed tray 37 is sent to the transport mechanism 16 so as to be sent to the manual feed tray. The paper feed roller 36 is controlled.

  The cap control unit 152 controls the tray moving device 84 based on the print mode of the print job stored in the execution job storage unit 130 and the uncapping flag stored in the flag storage unit 132. Specifically, when the print mode of the print job stored in the execution job storage unit 130 is the monochrome mode and the uncapping flag stored in the flag storage unit 132 is off, the color cap 73 is set. The tray moving device 84 is controlled so that is positioned at the “capping position”. In addition, when the print mode of the print job stored in the execution job storage unit 130 is the color mode or the uncapping flag stored in the flag storage unit 132 is in the on state, the color cap 73 is set to “Unclamp”. The tray moving device 84 is controlled to be positioned at the “capping position”. Further, when the print mode of the print job stored in the execution job storage unit 130 is in the low quality mode, the cap 71 for the processing liquid is in the “capping position”, and in the high quality mode, the cap 71 is in the “uncapping position”. The tray moving device 84 is controlled to be positioned.

  The interval adjustment unit 153 controls the lifting device 83 based on the print mode of the print job stored in the execution job storage unit 130. Specifically, when the print mode of the print job stored in the execution job storage unit 130 is the thin paper mode, the inkjet heads 1A and 1B and the precoat head 2 are positioned at the “first position”. The lifting device 83 is controlled (see FIG. 2A). When the print mode of the print job stored in the execution job storage unit 130 is the cardboard mode, the lifting / lowering device 83 is set so that the inkjet heads 1A and 1B and the precoat head 2 are positioned at the “second position”. Control (see FIG. 2B).

  The head control unit 154 controls the inkjet head 1 and the precoat head 2 based on the image data of the print job stored in the execution job storage unit 130 and the print mode. Specifically, when the print mode of the print job stored in the execution job storage unit 130 is the high quality mode, the head control unit 154 removes a precoat droplet having a predetermined volume based on the image data. The precoat head 2 is controlled so as to be ejected from the ejection port at a predetermined timing, and each inkjet head 1 is controlled so that an ink droplet having a predetermined volume is ejected from the ejection port at a predetermined timing. When the print mode of the print job stored in the execution job storage unit 130 is the low quality mode, the head control unit 154 controls the precoat head 2 so that the precoat liquid is not discharged and has a predetermined volume. Each inkjet head 1 is controlled so that the ink droplets are ejected from the ejection ports at a predetermined timing.

  When the print mode of the print job stored in the execution job storage unit 130 is the monochrome mode, the head control unit 154 controls the inkjet head 1 so that ink is ejected only from the inkjet head 1A. When the print mode is the color mode, the inkjet head 1 is controlled so that ink is ejected from all the inkjet heads 1A and 1B.

  The head control unit 154 also performs flushing (from a part or all of the ejection ports by driving the actuators of the heads 1 and 2 based on flushing data different from the image data) as a maintenance operation related to recovery / maintenance of ejection performance. The inkjet head 1 and the precoat head 2 are controlled so that the operation of forcibly discharging the ink or the precoat liquid (forced discharge) is performed. In addition, when the uncapping flag stored in the flag storage unit 132 is on, the head control unit 154 performs flushing every time the non-ejection limit time elapses during the time when ink is not ejected from the inkjet head 1B. The inkjet head 1B is controlled so as to be performed. Here, the non-ejection limit time is a minimum time during which the ink needs to be flushed from the ejection port of the inkjet head 1, and when the non-ejection limit time has elapsed, the ink that has been thickened by drying is removed. It is necessary to flush from the discharge port. In this embodiment, the non-ejection limit time is the minimum time that the ink needs to be flushed from the ejection port of the inkjet head 1, but the ink is purged from the ejection port of the inkjet head 1 (by using a pump or the like) 1 may be the minimum time required to apply pressure to the ink in 1 and force the ink to be ejected from all ejection ports.

  When the interrupt determination unit 136 determines that an interrupt process is to be performed, the interrupt control unit 138 interrupts the execution of the print job A and controls the job control unit 137 so that the print job B is executed. The input / output control unit 139 receives display control of the touch panel 90 and user input input via the touch panel 90.

  Next, the printing operation of the inkjet printer 101 will be described with reference to FIGS. As shown in FIG. 7, first, the job management unit 131 receives a print request from an external device such as a PC, and generates a print job (S1). Next, the job management unit 131 registers the generated print job in a queue (S2). Then, the job management unit 131 registers the print job at the head of the queue in the execution job storage unit 130 (S3).

  Next, the job control unit 137 starts executing the print job (print job A) registered in the execution job storage unit 130 (S4). Thereafter, the job management unit 131 determines whether or not the print job B instructed to interrupt the execution of the print job is generated (S5). If it is determined that the print job B has not been generated (S5: NO), the process proceeds to step S14.

  On the other hand, when it is determined that the print job B has been generated (S5: YES), the interrupt determination unit 136 performs an interrupt determination process described with reference to FIG. 8 (S6). In this interrupt determination process, it is determined whether to interrupt the execution of the print job A and execute the interrupt process for executing the print job B.

  In the process of step S6, if the interrupt determination unit 136 determines not to perform an interrupt process (S7: NO), the print job B is registered at the head of the queue of the job management unit 131 (S13). The process proceeds to step S14.

  In the process of step S14, the job control unit 137 continues the process of print job A, and proceeds to the process of step S15.

  On the other hand, if it is determined in step S6 that the interrupt determination unit 136 performs interrupt processing (S7: YES), the job control is performed so that the interrupt control unit 138 interrupts execution of the print job A. The unit 137 is controlled (S8). Next, the job management unit 131 adds 1 to the number of interruptions of the interrupt of the print job A, and starts measuring the interruption time of the print job A by the print job B (S9). In step S9, the job management unit 131 performs processing for registering print job A at the head of the queue.

  Next, the interrupt control unit 138 performs an interrupt job execution process described with reference to FIG. 10 (S10). In this interrupt execution process, the job control unit 137 executes the print job B. Thereafter, the job management unit 131 finishes counting the suspension time of the print job A by the print job B, and adds the measured suspension time to the interruption suspension time of the print job A (S11). Next, the job control unit 137 resumes execution of the print job A (S12), and the process proceeds to step S15.

  In the process of step S15, the job control unit 137 determines whether or not the execution of the print job A is completed. If it is determined that the execution of the print job A is not completed (S15: NO), the process returns to step S5. On the other hand, when it is determined that the execution of the print job A is completed (S15: YES), the job management unit 131 determines whether or not the print job B is registered in the queue (S16). If it is determined that the print job B is registered (S16: YES), the interrupt control unit 138 performs an interrupt job execution process described with reference to FIG. 10 (S17), and the process of step S16 is performed. Move.

  On the other hand, when the job management unit 131 determines that the print job B is not registered in the queue (S16: NO), the job management unit 131 has other standby jobs other than the print job B in the queue. It is determined whether or not there is (S18). If it is determined that there is a waiting job (S18: YES), the process returns to step S3. On the other hand, when it is determined that there is no standby job (S18: NO), the cap control unit 152 controls the tray moving device 84 so that the caps 71 to 73 are positioned at the “capping position” (S19). The printing operation is terminated.

  Next, the interrupt determination process shown in FIG. 7 will be described in detail with reference to FIG.

  First, the interrupt determination unit 136 determines whether the priority of the print job A stored in the execution job storage unit 130 is the same as the priority of the print job B that has been instructed to interrupt execution of the print job. It is determined whether or not (A1). When it is determined that the priorities are not the same (A1: NO), the interrupt determination unit 136 determines whether the priority of the print job B is higher than the priority of the print job A (A8). . If it is determined that the priority of the print job B is higher than the priority of the print job A (A8: YES), the process proceeds to step A11. On the other hand, if it is determined that the priority of the print job B is not higher than the priority of the print job A (A8: NO), the process proceeds to step A9.

  In the process of step A1, when the interrupt determination unit 136 determines that the priorities are the same (A1: YES), the interrupt determination unit 136 stores the print job A stored in the job management unit 131. It is determined whether or not the number of interruptions is less than the prescribed interruption number stored in the flag storage unit 132 and whether the interruption interruption time is less than the prescribed interruption time stored in the flag storage unit 132 ( A2). If it is determined that the number of interruptions of the print job A is not less than the prescribed interruption number, or the interruption time is not less than the prescribed interruption time (A2: NO), the process proceeds to step A9.

  On the other hand, when the interrupt determination unit 136 determines that the interrupt count of the print job A is less than the specified interrupt count and the interrupt interrupt time is less than the specified interrupt time (A2: YES), the interrupt is interrupted. The job execution time calculation unit 134 calculates the execution time of the print job B (A3). Next, whether or not the interrupt determination unit 136 is less than the specified interrupt job execution time stored in the flag storage unit 132 is the execution time of the print job B calculated by the interrupt job execution time calculation unit 134. Is determined (A4). If it is determined that the execution time of the print job B is not less than the prescribed interrupt job execution time (A4: NO), the process proceeds to step A9.

  On the other hand, when it is determined that the execution time of the print job B is less than the specified interrupt job execution time (A4: YES), the mode change time indexing unit 135 will be described with reference to FIG. Processing is performed (A5). In this mode change time indexing process, the print mode change time is determined based on the print mode of print job A and the print mode of print job B.

  Next, the remaining time calculation unit 133 calculates the remaining time until the print job A is completed for the print job A being executed by the job control unit 137 (A6). Then, the interrupt determination unit 136 calculates the remaining time calculated by the remaining time calculation unit 133 by the print mode change time calculated by the mode change time indexing unit 135 and the interrupt job execution time calculation unit 134. It is determined whether or not the sum of the execution times of the print job B is greater than the sum (A7). If it is determined that the remaining time is greater than the total value (A7: YES), the process proceeds to step A11. On the other hand, when it is determined that the remaining time is equal to or less than the total value (A7: YES), the process proceeds to step A9.

  In the process of step A9, it is determined that the interrupt determination unit 136 does not perform the interrupt process, the uncapping flag and the display flag stored in the flag storage unit 132 are initialized to the off state (A10), and the interrupt is performed. The determination process ends. In step A11, it is determined that the interrupt determination unit 136 performs an interrupt process, and the interrupt determination process ends.

  Next, the mode change time indexing process shown in FIG. 8 will be described in detail with reference to FIG.

  First, the mode change time index unit 135 determines whether or not the print modes related to the print modes of the print job A and the print job B are different between the color mode and the monochrome mode (B1). If it is determined that there is no difference between the color mode and the monochrome mode (B1: NO), the process proceeds to step B7.

  On the other hand, when it is determined that the color mode is different from the monochrome mode (B1: YES), the mode change time index unit 135 determines whether the print mode of the print job A is the color mode (B2). ). If it is determined that the print mode of the print job A is not the color mode (B2: NO), the process proceeds to step B6. On the other hand, when it is determined that the print mode of the print job A is the color mode (B2: YES), the mode change time index unit 135 executes the print job B calculated by the interrupt job execution time calculator 134. It is determined whether the time is less than the non-ejection limit time (B3). If it is determined that the execution time of the print job B is less than the non-ejection limit time (B3: YES), the uncapping flag stored in the flag storage unit 132 is turned on (B5), and the process of step B7 is performed. Move on to processing.

  On the other hand, when it is determined that the execution time of the print job B is not less than the non-ejection limit time (B3: NO), the display flag stored in the flag storage unit 132 is turned on (B4), and step B6 is performed. Move on to processing.

  In the process of step B6, the mode change time indexing unit 135 adds the time required to reciprocate the color cap 73 between the “capping position” and the “uncapping position” to the mode change time. When the process of step B6 is completed, the process proceeds to step B7.

  In the process of step B7, the mode change time indexing unit 135 determines whether the print modes related to the quality modes of the print job A and the print job B are different between the low quality mode and the high quality mode. If it is determined that there is no difference between the low quality mode and the high quality mode (B7: NO), the process proceeds to step B9. On the other hand, when it is determined that the low quality mode and the high quality mode are different (B7: YES), the mode change time indexing unit 135 moves the cap 71 for the processing liquid to the “capping position” and the “uncapping position”. ”Is added to the mode change time (B8), and the process proceeds to step B9.

  In the process of step B9, the mode change time indexing unit 135 determines whether the print modes related to the quality modes of the print job A and the print job B are different between the thin paper mode and the thick paper mode. If it is determined that there is no difference between the thin paper mode and the thick paper mode (B9: NO), the mode change time indexing process is terminated. On the other hand, when it is determined that the thin paper mode and the thick paper mode are different (B7: YES), the mode change time indexing unit 135 moves the heads 1 and 2 to the “first position” and the “second position”. Is added to the mode change time (B10), and the mode change time indexing process is terminated.

  Next, the interrupt job execution process shown in FIG. 7 will be described in detail with reference to FIG.

  First, the interrupt control unit 138 registers the print job B in the execution job storage unit 130 (C2). Next, the input / output control unit 139 determines whether or not the display flag stored in the flag storage unit 132 is on (C2). If it is determined that the display flag is not on (C2: NO), the process proceeds to step C6.

  On the other hand, if it is determined that the display flag is on (C2: YES), the input / output control unit 139 selects the user to select whether or not to move the color cap 73 to the “capping position”. A screen is displayed on the touch panel 90 (C3). Specifically, image formation is performed by a method that increases the consumption of color ink but shortens the waiting time of the user, or the image is processed by a method that increases the waiting time of the user while reducing the consumption of color ink. A selection screen for allowing the user to select whether to execute formation is displayed on touch panel 90.

  Next, the input / output control unit 139 determines whether or not the selection result received from the user is to move the color cap 73 to the “capping position” (C4). If the selection result is to move the color cap 73 to the “capping position” (C4; YES), the process proceeds to step C6. On the other hand, if the selection result does not move the color cap 73 to the “capping position” (C4: NO), the uncapping flag stored in the flag storage unit 132 is turned on (C5). The process proceeds to step C6.

  In the process of step C6, it is determined whether or not the uncapping flag stored in the flag storage unit 132 is on. If it is determined that the uncapping flag is not in the on state (C6: NO), the job control unit 137 determines the normal print mode based on the print mode of the print job B stored in the execution job storage unit 130. A change operation is performed (C7). Specifically, for example, when the print mode of the print job A and the print mode of the print job B are different between the monochrome mode and the color mode, the job control unit 137 sets the color cap 73 to “capping position”. To “uncapping position” or “uncapping position” to “capping position”. When the print mode of the print job A and the print mode of the print job B are different between the low quality mode and the high quality mode, the job control unit 137 moves the cap 71 for the processing liquid from the “capping position” to “ It is moved from “uncapping position” or “uncapping position” to “capping position”. When the print mode of the print job A and the print mode of the print job B are different between the thin paper mode and the thick paper mode, the job control unit 137 moves the heads 1 and 2 from the “first position” to the “second position”. Position ”or“ second position ”to“ first position ”. When the process of step C7 ends, the process proceeds to step C9.

  On the other hand, when it is determined that the uncapping flag is on (C6: NO), the job control unit 137 performs a specific print mode change operation (C8). Specifically, since the print job A is in the color mode and the print job B is in the monochrome mode, the print mode is different, but the job control unit 137 sets the color cap 73 to the “uncapping position”. The tray moving device 84 is controlled to stay. The case where the print mode of the print job A and the print mode of the print job B are different between the low quality mode and the high quality mode and the case where the print mode is different between the thin paper mode and the thick paper mode are the same as the processing of step C7. When the process of step C8 ends, the process proceeds to step C9.

  In step C9, the job control unit 137 starts execution of the print job B. Thereafter, the job control unit 137 determines whether or not the uncapping flag stored in the flag storage unit 132 is on (C10). If it is determined that the uncapping flag is not on (C10: NO), the process proceeds to step C12.

  On the other hand, when it is determined that the uncapping flag is in the on state (C10: YES), the job control unit 137 causes the time during which no ink is ejected from the inkjet head 1B to pass every non-ejection limit time. The inkjet head 1B is controlled (C11) so that flushing is performed, and the process proceeds to step C12.

  In step C12, the job control unit 137 determines whether or not the print job B is completed. If it is determined that the print job B has not been completed (C12: NO), the process returns to step C10. On the other hand, when it is determined that the print job B is completed (C12: YES), the interrupt control unit 138 determines whether the print job A is registered in the queue of the job management unit 131 (C13). ). If it is determined that the print job A is not registered (C13: NO), the process proceeds to step C16.

  On the other hand, when it is determined that the print job A is registered (C13: YES), the interrupt control unit 138 registers the print job A in the execution job storage unit 130 (C14), and prints the print job A. Based on the mode, the printing mode is changed (C15). Specifically, the job control unit 137 performs an operation opposite to the operation in step C7 or step C8. Thereafter, the uncapping flag and the display flag stored in the flag storage unit 132 are initialized to an off state (C16), and the interrupt job execution process is terminated.

  As described above, according to the present exemplary embodiment, when the remaining time of the print job A being executed by the job control unit 137 is equal to or shorter than the print mode change time, the interruption process is not performed, so that the user of the print job A is more than necessary. Can be prevented, and the number of times the print mode is changed can be reduced, so that the throughput for executing the entire print job can be improved.

  Further, according to the present embodiment, the interrupt determination unit 136 determines whether or not to perform an interrupt process so that the print job with a high priority is executed first, so the print job with a high priority is given priority. And can be executed.

  Further, according to the present embodiment liquid, the interrupt determination unit 136 determines that the interrupt suspension time of the print job A stored in the job management unit 131 is less than the interrupt specified interrupt time or the interrupt interrupt count is less than the interrupt specified interrupt count. Since no interrupt processing is performed, the user of the print job A can be prevented from waiting for a long time.

  Further, according to the present embodiment, when the remaining time of the print job A being executed by the job control unit 137 is equal to or less than the sum of the execution time of the print job B and the change time of the print mode, an interrupt process is performed. Therefore, the user of the print job A can be prevented from waiting more than necessary, and the number of times of changing the print mode can be reduced, so that the throughput for executing the entire print job is improved. be able to.

  Further, according to the present embodiment, the interrupt determination unit 136 does not perform interrupt processing when the execution time of the print job B is equal to or longer than the interrupt job execution specified time stored in the flag storage unit 132. Therefore, it is possible to prevent the user of the first print job from waiting more than necessary.

  Further, according to the present embodiment, when the print mode of the print job stored in the execution job storage unit 130 is the monochrome mode, the ejection surface 1b of the inkjet head 1B is surrounded by the color cap 73. It is possible to suppress drying of the ink in the vicinity of the ejection opening of the inkjet head 1B. In addition, since the time required to move the color cap 73 when changing the print mode between the monochrome mode and the color mode is included in the change time of the print mode, it is determined whether or not to perform an interrupt process. As a result, it is possible to reduce the possibility that the user will wait for a long time, and to improve the throughput for executing the entire print job.

  According to the present embodiment, when the print mode of the print job A is the color mode and the print mode of the print job B is the monochrome mode, the execution time of the print job B is less than the non-ejection limit time, If the interrupt determination unit 136 determines that an interrupt process is to be performed, the print job B can be executed without moving the color cap 73, thereby reducing the time required for changing the print mode. As a result, the user can be prevented from waiting more than necessary, and the throughput for executing the entire print job can be improved.

  Further, according to the present embodiment, when the print mode of the print job A is the color mode and the print mode of the print job B is the monochrome mode, the non-ejection limit time is exceeded and the interrupt determination unit 136 performs an interrupt process. If it is determined that the color cap 73 is to be positioned at the “uncapping position” even when the print job B is executed, it is determined by the user's selection. Therefore, the user determines whether to perform image formation by a method that increases the ink consumption but shortens the waiting time of the user, or to execute the image formation by a method that reduces the ink consumption but increases the waiting time of the user. Can be selected.

  Further, according to the present embodiment, when the color cap 73 is positioned at the “uncapping position” and the print job B whose print mode is the monochrome mode is being executed, the discharge port of the inkjet head 1B is used. Since ink is flushed, it is not necessary to perform flushing after the end of print job B. As a result, the user can be prevented from waiting more than necessary, and the throughput for executing the entire print job can be improved. be able to.

  Further, according to the present embodiment, when the print mode of the print job stored in the execution job storage unit 130 is the low quality mode, the ejection surface 2a of the precoat head 2 is surrounded by the processing liquid cap 71. Therefore, drying of the precoat liquid near the discharge port of the precoat head 2 can be suppressed. In addition, since the time required to move the processing liquid cap 71 when the print mode is changed between the low quality mode and the high quality mode is included in the print mode change time, whether or not to perform interrupt processing is determined. Thus, it is possible to reduce the possibility that the user will wait for a long time, and to improve the throughput for executing the entire print job.

  In addition, according to the present embodiment, the interval between the support surface 8a and the ejection surfaces 1a, 1b, and 2a of the heads 1 and 2 is changed according to the thickness of the paper P, so that a high-quality image is formed on the paper P. can do. In addition, since the time associated with the movement of the processing liquid cap 71 when the print mode is changed between the thin paper mode and the thick paper mode is included in the print mode change time, it is determined whether or not to perform interrupt processing. Therefore, the possibility that the user will wait for a long time can be reduced, and the throughput for executing the entire print job can be improved.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, in the above-described embodiment, the interrupt determination unit 136 determines that the remaining time of the print job A calculated by the remaining time calculation unit 133 is the execution time of the print job B calculated by the interrupt job execution time calculation unit 134. And the print mode change time calculated by the mode change time indexing unit 135 is larger than the sum of the values, the interrupt processing is determined to be performed. It may be determined that the interruption process is performed when the change time is longer than the change time. Further, regardless of the remaining time of the print job A, it may be determined that the interruption process is performed when the print mode change time is shorter than the predetermined time. The print job B execution time calculated by the interrupt job execution time calculation unit 134 and the print mode change time calculated by the mode change time indexing unit 135 are added together regardless of the remaining time of the print job A. It may be determined that the interrupt process is performed when the obtained value is smaller than the predetermined time.

  Further, in the above-described embodiment, the mode change time indexing unit 135 performs printing related to the time and quality associated with the reciprocating movement of the color cap 73 when the print job A and the print job B have different print modes. When the mode is different, the time required for the reciprocating movement of the processing liquid cap 71 and when the printing mode for the recording medium is different, the time required for the reciprocating movement of the heads 1 and 2 are added to the printing mode change time. However, when the printing mode is changed, the movement operation of the color cap 73, the movement operation of the processing liquid cap 71, and the movement operation of the heads 1 and 2 can be performed simultaneously in parallel. If this is the case, only the longest time among the time associated with these moving operations may be added to the print mode change time.

  In the above-described embodiment, the print job B is not interrupted for the print job B instructed to interrupt the execution of the print job. However, the print job B is also printed. Job interruption may be performed. In this case, an interrupt determination process is performed by the interrupt determination unit 136 between the print job B (hereinafter referred to as print job C) that interrupts the print job B and the print job B as described above. If the interrupt determination unit 136 determines that no interrupt processing is to be performed on the print job B, it determines whether to perform interrupt processing between the print job C and the print job A. If it is determined that no interrupt processing is performed for the print job A, the print job C is registered after the print job A in the queue of the job management unit 131. On the other hand, when it is determined that the interrupt processing is performed for the print job A, the print job C is registered before the print job A in the queue of the job management unit 131.

  In the above-described embodiment, when the interrupt determination unit 136 determines not to perform interrupt processing, the print job B is configured to be registered at the head of the queue of the job management unit 131. When a print job having a higher priority than the print job B is registered in the queue, the print job B is registered in the order immediately after the print job having a higher priority than the print job B. May be.

  In the above-described embodiment, the caps 71 to 73 are brought into contact with the ejection surfaces 1a, 1b, and 2a by moving the caps 71 to 73 upward in the capping operation. A configuration may be employed in which the caps 71 to 73 are brought into contact with the ejection surfaces 1a, 1b, and 2a by being moved downward.

  In the above-described embodiment, not only the black (K) inkjet head 1A but also the cyan (C), magenta (M), and yellow (Y) inkjet head 1B are used. The structure which does not do may be sufficient. The transport mechanism 16 includes two belt rollers 6 and 7, a transport belt 8, a tension roller 10, and a platen 18. However, the transport mechanism 16 does not have a transport belt and a plurality of spur rollers. The sheet P may be transported by a platen that supports the sheet P.

  Further, in the above-described embodiment, the inkjet printer 101 has a configuration having six printing modes, that is, a monochrome mode and a color mode for printing, a low quality mode and a high quality mode for quality, and a thin paper mode and a thick paper mode for a recording medium. However, the type of print mode is not limited to this, and it may have seven or more print modes, or may have only two print modes.

  The present invention is also applicable to an image forming apparatus that discharges liquid other than ink. Further, the present invention is not limited to a printer, and can be applied to a facsimile, a copier, and the like. In addition, the action of the precoat liquid on the ink includes agglomeration or precipitation of components (pigments and dyes) in the ink by a chemical reaction caused by mixing the ink and the precoat liquid. It also includes aggregating or precipitating components (pigments and dyes) in the ink without chemical reaction. In general, a precoat liquid for aggregating pigment pigment is used for pigment ink, and a precoat liquid for depositing dye pigment is used for dye ink as described above. It may have both effects of precipitation.

1 Inkjet head (ejection head)
2 Precoat head 1a, 1b, 2a Discharge surface 71-73 Cap 83 Lifting device 84 Tray moving device (cap driving means)
100 controller 101 inkjet printer (image forming apparatus)
131 Job management unit (storage means)
133 Remaining time calculation unit (remaining time calculation means)
134 Interrupt Job Execution Time Calculation Unit 135 Mode Change Time Index Unit (Mode Change Time Index Unit)
136 Interrupt judgment part (interrupt judgment means)
137 Job control unit 138 Interrupt control unit P1 Plain paper P2 Thick paper

Claims (11)

An image forming apparatus having a plurality of print modes,
Job execution means for executing a print job related to image formation on a recording medium;
Remaining time calculation means for calculating the remaining time until the first print job is completed with respect to the first print job being executed by the job execution means;
Transition from the first print job to the second print job based on the print mode of the first print job and the print mode of the second print job instructed to interrupt the execution of the print job And mode change time indexing means for determining a print mode change time associated with the transition from the second print job to the first print job;
When the remaining time calculated by the remaining time calculating unit is at least larger than the change time calculated by the mode change time calculating unit, the first print job is interrupted and the second printing is performed. Interrupt determination means for determining whether to perform interrupt processing for executing a job;
Interrupt control means for controlling the job execution means so that the first print job is interrupted and the second print job is executed when the interrupt determination means determines to perform the interrupt processing. It equipped with a door,
The job execution means includes:
A color discharge head having a color discharge surface in which discharge ports for discharging a color recording liquid on a recording medium are formed;
A black discharge head having a black discharge surface on which a discharge port for discharging a black recording liquid on a recording medium is formed;
A color cap capable of surrounding the color discharge surface of the color discharge head;
Cap driving means for moving the color cap between a color capping position that surrounds the color ejection surface and a color uncapping position that exposes the color ejection surface;
Control means for controlling the color and black ejection heads and the cap driving means;
With
The plurality of print modes include a monochrome mode and a color mode,
When the printing mode is the monochrome mode, the control unit controls the cap driving unit so that the color cap is positioned at the color capping position, and the black recording is performed from the black ejection surface. Controlling the color and black discharge heads so as to discharge the liquid and prohibit the discharge of the color recording liquid from the color discharge surface;
When the printing mode is the color mode, the control means controls the cap driving means so that the color cap is positioned at the color uncapping position, and the black discharge surface Controlling the color and black ejection heads so that the recording liquid is ejected from the color ejection surface, respectively.
The mode change time indexing unit is configured to detect the color cap when the print mode of the first print job and the print mode of the second print job are different between the monochrome mode and the color mode. An image forming apparatus characterized in that the change time includes a time required to reciprocate the color between the color capping position and the color uncapping position . An image forming apparatus having a plurality of print modes,
Job execution means for executing a print job related to image formation on a recording medium;
Remaining time calculation means for calculating the remaining time until the first print job is completed with respect to the first print job being executed by the job execution means;
Transition from the first print job to the second print job based on the print mode of the first print job and the print mode of the second print job instructed to interrupt the execution of the print job And mode change time indexing means for determining a print mode change time associated with the transition from the second print job to the first print job;
When the remaining time calculated by the remaining time calculating unit is at least larger than the change time calculated by the mode change time calculating unit, the first print job is interrupted and the second printing is performed. Interrupt determination means for determining whether to perform interrupt processing for executing a job;
Interrupt control means for controlling the job execution means so that the first print job is interrupted and the second print job is executed when the interrupt determination means determines to perform the interrupt processing. When
With
The job execution means includes:
Conveying means for conveying the recording medium in the conveying direction;
A black discharge head having a black discharge surface on which a discharge port for discharging a black recording liquid on a recording medium is formed;
A plurality of discharge ports are provided on the upstream side of the black discharge head with respect to the transport direction, and discharge a treatment liquid that acts on the black recording liquid to aggregate or deposit components in the black recording liquid. A treatment liquid ejection head having a treated liquid ejection surface;
A treatment liquid cap capable of surrounding the treatment liquid ejection surface of the treatment liquid ejection head;
Cap driving means for moving the processing liquid cap between a processing liquid capping position surrounding the processing liquid ejection surface and a processing liquid uncapping position exposing the processing liquid ejection surface;
And a control means for controlling the black and processing liquid discharge heads and the cap driving means,
The plurality of print modes include a low quality mode and a high quality mode,
When the printing mode is the low quality mode, the control unit controls the cap driving unit so that the processing liquid cap is positioned at the processing liquid capping position, and the control unit drives the black discharge surface from the black discharge surface. Controlling the black and processing liquid discharge heads so that the black recording liquid is discharged and discharging of the processing liquid from the processing liquid discharge surface is prohibited;
When the printing mode is the high quality mode, the control unit controls the cap driving unit so that the processing liquid cap is located at the processing liquid uncapping position, and from the black discharge surface. Controlling the black and processing liquid ejection heads so that the black recording liquid is ejected from the processing liquid ejection surface, respectively.
The mode change time indexing unit is configured to perform the processing when the print mode of the first print job and the print mode of the second print job are different from each other in the low quality mode and the high quality mode. images forming device you characterized in that the time with the liquid cap for reciprocating movement between an uncapped position for the processing liquid capping position for the treatment liquid, is included in the change time. An image forming apparatus having a plurality of print modes,
Job execution means for executing a print job related to image formation on a recording medium;
Remaining time calculation means for calculating the remaining time until the first print job is completed with respect to the first print job being executed by the job execution means;
Transition from the first print job to the second print job based on the print mode of the first print job and the print mode of the second print job instructed to interrupt the execution of the print job And mode change time indexing means for determining a print mode change time associated with the transition from the second print job to the first print job;
When the remaining time calculated by the remaining time calculating unit is at least larger than the change time calculated by the mode change time calculating unit, the first print job is interrupted and the second printing is performed. Interrupt determination means for determining whether to perform interrupt processing for executing a job;
Interrupt control means for controlling the job execution means so that the first print job is interrupted and the second print job is executed when the interrupt determination means determines to perform the interrupt processing. When
With
The job execution means includes:
An ejection head having an ejection surface on which ejection ports for ejecting a recording liquid onto a recording medium are formed;
A transport unit that has a support surface for supporting the recording medium, and transports the recording medium so that the recording medium supported by the support surface passes through a position facing the ejection surface;
By moving the discharge head between a first position and a second position where the distance between the support surface and the support surface is larger than the first position, the discharge surface of the discharge head and the support surface And an interval adjusting means capable of adjusting the interval of
The plurality of printing modes include a thin paper mode for forming an image on a first recording medium and a thick paper mode for forming an image on a second recording medium thicker than the first recording medium,
The interval adjusting means includes
When the printing mode is the thin paper mode, the ejection head is positioned at the first position, and when the printing mode is the thick paper mode, the ejection head is positioned at the second position.
The mode change time indexing unit controls the ejection head when the print mode of the first print job and the print mode of the second print job are different from each other in the thin paper mode and the thick paper mode. It said first position and the time involved to reciprocate between the second position, images forming device you said to be included in the change time. 4. The interrupt determination unit according to claim 1, wherein the interrupt determination unit determines to perform the interrupt processing only when the priority of the first print job and the priority of the second print job are the same . The image forming apparatus according to one item . Storage means for storing at least one of the interruption time of the first print job interrupted by the interruption processing and the number of interruptions;
The interrupt determination unit determines to perform the interrupt processing when the interruption time of the first print job stored in the storage unit is less than a prescribed time or when the interruption number is less than a prescribed number. The image forming apparatus according to claim 1 . An interrupt job execution time calculating means for calculating an execution time of the second print job;
The interrupt determination unit is configured to calculate the remaining time calculated by the remaining time calculating unit, the change time calculated by the mode change time indexing unit, and the interrupt job execution time calculating unit. The image forming apparatus according to claim 1 , wherein the interrupt processing is determined to be performed when the execution time of the second print job is greater than a sum of execution times. Said interrupt determining means, when the execution time of the second print job which is calculated by the interrupt job execution time calculation means is less than the least the specified time, claim 6 for determining to perform the interrupt processing The image forming apparatus described in 1. An image forming apparatus having a plurality of print modes,
Job execution means for executing a print job related to image formation on a recording medium;
Remaining time calculation means for calculating the remaining time until the first print job is completed with respect to the first print job being executed by the job execution means;
Transition from the first print job to the second print job based on the print mode of the first print job and the print mode of the second print job instructed to interrupt the execution of the print job And mode change time indexing means for determining a print mode change time associated with the transition from the second print job to the first print job;
When the remaining time calculated by the remaining time calculating unit is at least larger than the change time calculated by the mode change time calculating unit, the first print job is interrupted and the second printing is performed. Interrupt determination means for determining whether to perform interrupt processing for executing a job;
Interrupt control means for controlling the job execution means so that the first print job is interrupted and the second print job is executed when the interrupt determination means determines to perform the interrupt processing. When,
Interrupt job execution time calculating means for calculating the execution time of the second print job;
With
The job execution means includes:
A color discharge head having a color discharge surface in which discharge ports for discharging a color recording liquid on a recording medium are formed;
A black discharge head having a black discharge surface on which a discharge port for discharging a black recording liquid on a recording medium is formed;
A color cap capable of surrounding the color discharge surface of the color discharge head;
Cap driving means for moving the color cap between a color capping position that surrounds the color ejection surface and a color uncapping position that exposes the color ejection surface;
Control means for controlling the color and black ejection heads and the cap driving means;
With
The plurality of print modes include a monochrome mode and a color mode,
When the printing mode is the monochrome mode, the control unit controls the cap driving unit so that the color cap is positioned at the color capping position, and the black recording is performed from the black ejection surface. Controlling the color and black discharge heads so as to discharge the liquid and prohibit the discharge of the color recording liquid from the color discharge surface;
When the printing mode is the color mode, the control means controls the cap driving means so that the color cap is positioned at the color uncapping position, and the black discharge surface Controlling the color and black ejection heads so that the recording liquid is ejected from the color ejection surface, respectively.
The mode change time indexing unit is configured to detect the color cap when the print mode of the first print job and the print mode of the second print job are different between the monochrome mode and the color mode. The change time includes a time required to reciprocate the color between the color capping position and the color uncapping position.
When the print mode of the first print job is the color mode and the print mode of the second print job is the monochrome mode, the interrupt job execution time calculation unit calculates the first job. When the execution time of the print job of 2 is less than the non-ejection limit time during which the color recording liquid needs to be forcibly ejected from the ejection port of the color ejection head, the mode change time indexing means The time required for reciprocating the color cap between the color capping position and the color uncapping position is not included in the change time, and the change time is calculated.
When the interrupt determination unit determines that the interrupt processing is to be performed, the job execution unit is positioned at the color uncapping position even when executing the second print job. an image forming apparatus comprising said cap driving means to control by said control means so. An image forming apparatus having a plurality of print modes,
Job execution means for executing a print job related to image formation on a recording medium;
Remaining time calculation means for calculating the remaining time until the first print job is completed with respect to the first print job being executed by the job execution means;
Transition from the first print job to the second print job based on the print mode of the first print job and the print mode of the second print job instructed to interrupt the execution of the print job And mode change time indexing means for determining a print mode change time associated with the transition from the second print job to the first print job;
When the remaining time calculated by the remaining time calculating unit is at least larger than the change time calculated by the mode change time calculating unit, the first print job is interrupted and the second printing is performed. Interrupt determination means for determining whether to perform interrupt processing for executing a job;
Interrupt control means for controlling the job execution means so that the first print job is interrupted and the second print job is executed when the interrupt determination means determines to perform the interrupt processing. When,
Interrupt job execution time calculating means for calculating the execution time of the second print job;
With
The job execution means includes:
A color discharge head having a color discharge surface in which discharge ports for discharging a color recording liquid on a recording medium are formed;
A black discharge head having a black discharge surface on which a discharge port for discharging a black recording liquid on a recording medium is formed;
A color cap capable of surrounding the color discharge surface of the color discharge head;
Cap driving means for moving the color cap between a color capping position that surrounds the color ejection surface and a color uncapping position that exposes the color ejection surface;
Control means for controlling the color and black ejection heads and the cap driving means;
With
The plurality of print modes include a monochrome mode and a color mode,
When the printing mode is the monochrome mode, the control unit controls the cap driving unit so that the color cap is positioned at the color capping position, and the black recording is performed from the black ejection surface. Controlling the color and black discharge heads so as to discharge the liquid and prohibit the discharge of the color recording liquid from the color discharge surface;
When the printing mode is the color mode, the control means controls the cap driving means so that the color cap is positioned at the color uncapping position, and the black discharge surface Controlling the color and black ejection heads so that the recording liquid is ejected from the color ejection surface, respectively.
The mode change time indexing unit is configured to detect the color cap when the print mode of the first print job and the print mode of the second print job are different between the monochrome mode and the color mode. The change time includes a time required to reciprocate the color between the color capping position and the color uncapping position.
When the print mode of the first print job is the color mode and the print mode of the second print job is the monochrome mode, the interrupt job execution time calculation unit calculates the first job. The execution time of the second print job is equal to or longer than a non-ejection limit time required to forcibly eject the color recording liquid from the ejection port of the color ejection head, and the interrupt determination unit performs the interrupt processing. When you decide to do it,
The job execution means determines whether or not to place the color cap at the color uncapping position even when executing the second print job, based on the determination result. An image forming apparatus, wherein the cap driving unit is controlled by the control unit . When the job execution unit is executing the second print job in a state where the cap driving unit is controlled by the control unit so that the color cap is positioned at the color uncapping position.
10. The color ejection head according to claim 9 , wherein the control unit of the job execution unit controls the color ejection head so that the color recording liquid is forcibly ejected from the ejection port of the color ejection head. Image forming apparatus. Have a plurality print modes including a monochrome mode and color mode, and the color ejection head having a color ejection surface in which the discharge ports are formed for ejecting the recording liquid of the color on the recording medium, black recording medium A black discharge head having a black discharge surface in which discharge ports for discharging the recording liquid are formed, a color cap capable of surrounding the color discharge surface of the color discharge head, and the color cap An image forming apparatus comprising: a color capping position that surrounds the color discharge surface; and a cap driving unit that moves the color discharge position to expose the color discharge surface.
Job execution means for controlling the color and black ejection heads and the cap driving means to execute a print job relating to image formation on a recording medium;
Remaining time calculation means for calculating the remaining time until the first print job is completed with respect to the first print job being executed by the job execution means;
Transition from the first print job to the second print job based on the print mode of the first print job and the print mode of the second print job instructed to interrupt the execution of the print job And mode change time indexing means for determining a print mode change time associated with the transition from the second print job to the first print job;
When the remaining time calculated by the remaining time calculating unit is at least larger than the change time calculated by the mode change time calculating unit, the first print job is interrupted and the second printing is performed. Interrupt determination means for determining whether to perform interrupt processing for executing a job;
The color and black ejection heads, so that the first print job is interrupted and the second print job is executed when the interrupt determination unit determines to perform the interrupt process ; Function as interrupt control means for controlling the cap drive means ,
The job execution means includes:
When the printing mode is the monochrome mode, the cap driving unit is controlled so that the color cap is positioned at the color capping position, and the black recording liquid is discharged from the black discharge surface. Controlling the color and black ejection heads so that ejection of the color recording liquid from the color ejection surface is prohibited;
When the printing mode is the color mode, the cap driving unit is controlled so that the color cap is positioned at the color uncapping position, and the black recording liquid is discharged from the black discharge surface. Controlling the color and black discharge heads to discharge the color recording liquid from the color discharge surfaces,
The mode change time indexing unit is configured to detect the color cap when the print mode of the first print job and the print mode of the second print job are different between the monochrome mode and the color mode. A control program for an image forming apparatus , wherein the change time includes a time required to reciprocate the image between the color capping position and the color uncapping position .

Images