Printing device, control method thereof, and program

Abstract

To provide a printing device, a control method thereof, and a program that allow downtime to be reduced while restricting an ink consumption due to periodic cleaning.SOLUTION: A printing device executes periodic cleaning when an accumulated printing time obtained by accumulating printing time from a previous cleaning attains a first threshold, in a constitution of cleaning a print head provided with a nozzle for discharging ink. The printing device comprises: a counting part for calculating an accumulated printing time that is an accumulation of printing time (S306 and the like); and a control part for executing cleaning ahead of schedule at a job delimiting position, if a job delimiting position accompanied by printing stop exists, when a plurality of continuous printing jobs exists in an accumulated printing time width in which an accumulated printing time counted by the counting part is less than the first threshold but equal to or more than a second threshold being smaller than the first threshold (204, S302, S304, S307, S309 and the like).SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a printing device that cleans a print head provided with nozzles for ejecting ink, a control method thereof, and a program that periodically performs cleaning when the cumulative printing time reaches a predetermined threshold value in a configuration where the cumulative printing time reaches a predetermined threshold value.

Background Art

[0002] Conventionally, in an image forming apparatus that ejects ink to form an image, in order to maintain good print quality, a method of performing periodic cleaning when the cumulative printing time from the previous cleaning execution satisfies a predetermined condition has been adopted. For example, Patent Document 1 discloses a method of performing cleaning when the cumulative printing time becomes a predetermined time or more before printing starts or after printing ends. Further, Patent Document 2 discloses a method of once stopping printing and performing cleaning when the cumulative printing time becomes a predetermined time or more during printing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the method disclosed in Patent Document 1, since the timing of regular cleaning is limited to before the start of printing and after the end of printing, when the printing time is long, there is a problem that it is difficult to execute regular cleaning at a suitable timing. That is, when performing regular cleaning before the start of printing, there is a concern that the execution of cleaning is too early (in other words, the execution interval is too short), and the ink consumption due to cleaning increases. On the other hand, when performing regular cleaning after the end of printing, there is a concern that the execution of regular cleaning is too late (in other words, the execution interval is too long), and good print quality cannot be maintained.

[0005] Also, in the method disclosed in Patent Document 2, since printing is temporarily stopped to execute cleaning, there is a problem that downtime occurs every time regular cleaning is executed.

[0006] An object of the present invention is to provide a printing device, a control method thereof, and a program that can suppress ink consumption due to cleaning and reduce downtime.

Means for Solving the Problems

[0007] In order to achieve the above object, the present invention is configured to clean a print head provided with nozzles for discharging ink, and in a printing device that executes regular cleaning when the cumulative printing time obtained by accumulating the printing time since the previous cleaning reaches a first threshold value, a counting unit that counts the cumulative printing time obtained by accumulating the printing time, and when there are a plurality of consecutive print jobs in a cumulative printing time range where the cumulative printing time counted by the counting unit is less than the first threshold value and is equal to or greater than a second threshold value smaller than the first threshold value, and there is a job separation position involving printing stop, a control unit that executes cleaning in advance at the job separation position.

Effects of the Invention

[0008] According to the present invention, an effect of being able to reduce downtime while suppressing ink consumption by cleaning can be obtained.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

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Figure 14

Modes for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the configurations described in the following embodiments are merely examples, and the scope of the present invention is not limited by the configurations described in the embodiments. First, a first embodiment of the present invention will be described. The same reference numerals will be used for the same configurations and processes for description. In this embodiment, an image forming system 200 will be described as an example of a printing device.

[0011] <<First Embodiment>> In the first embodiment, a mode of performing cleaning in advance at the stop timing between print jobs will be described with reference to the drawings.

[0012] (FIG. 1: Configuration diagram of image forming system 200) FIG. 1 is a configuration diagram of an image forming system 200 according to the first embodiment. The image forming system 200 includes a paper feeding device 103, an image forming device 100, a paper discharging device 104, a UI operation panel 101, and a control PC 113. The image forming system 200 forms an image on a continuous paper (hereinafter also referred to as "roll paper") 110, which is a roll-shaped recording medium capable of continuous image formation used in this embodiment.

[0013] (Paper feeding device 103) The paper feeding device 103 supplies the roll paper 110 to the image forming device 100. The paper feeding device 103 rotates the paper tube of the roll paper 110 around the rotation axis 111, and conveys the roll paper 110 wound around the paper tube to the image forming device 100 at a constant speed via a plurality of rollers (conveying rollers, paper feeding rollers, etc.). Note that an oblique correction device 109 for appropriately changing the paper passing direction of the roll paper 110 is provided above the paper feeding device 103.

[0014] (Paper discharging device 104) The paper discharging device 104 discharges the roll paper 110 from the image forming system 200. The paper discharging device 104 rotates the rotating shaft 112 at a constant speed via a plurality of rollers (such as a conveying roller and a paper discharging roller) for the roll paper 110 conveyed from the image forming device 100, and winds it up in a roll shape as the product of the roll paper 110. In the paper discharging device 104, the roll paper 110 is wound around the paper tube of the rotating shaft 112 and held in a roll shape. Before the start of printing, the roll paper 110 is passed from the paper feeding device 103 through a predetermined position in the image forming device 100 to the paper discharging device 104. Specifically, the roll paper 110 is mounted on the paper feeding device 103, and the roll paper 110 mounted on the paper feeding device 103 is sequentially passed under the printing device 102 provided in the image forming device 100 via the skew correction device 109.

[0015] (Image forming device 100) The image forming device 100 has print heads 114 to 118 corresponding to each of a plurality of printing primary colors (CMYK), and prints each printing primary color (CMYK). 114 to 118 are print heads for primer liquid, black, cyan, magenta, and yellow respectively. The print heads 114 to 118 for each printing primary color print characters, images, etc. on the roll paper 110. A large number of nozzles are provided in the print head, and an image is printed by discharging ink from the nozzles onto the roll paper 110. The roll paper 110 is further passed under the drying device 105 and above the cooling devices 107 and 108, and sequentially passed under the connection scanner device 106. Then, the roll paper 110 is wound around the rotating shaft 112 of the paper discharging device 104. The print head performs periodic cleaning when the cumulative printing time obtained by accumulating the printing time since the previous cleaning reaches a predetermined threshold value (the first threshold value).

[0016] (UI operation panel 101: Control PC 113) When printing, after passing the roll paper 110 into the image forming system 200, it is input as an image forming job (hereinafter simply referred to as "print job" or "job") to the control PC 113 of the image forming system 200. After the print job is input, printing is started by pressing the print start button on the UI operation panel 101.

[0017] <Figure 2: Functional configuration diagram of the image forming system 200> Figure 2 is a functional configuration diagram of the image forming system 200. The image forming system 200 includes a paper conveyance unit 201, an image forming unit 202, a communication unit 203, a control unit 204, a storage unit 205, an operation display unit 206, an inspection unit 207, a paper feed control unit 208, a winding control unit 209, and a fixing unit 210.

[0018] (Control unit 204) The control unit 204 controls each unit connected to itself. The control unit 204 is composed of, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM, etc. The CPU of the control unit 204 reads out various programs such as system programs and processing programs stored in the storage unit 205 and expands them in the RAM, and executes various processes according to the expanded programs. Thereby, desired control and processing are realized. For example, the control unit 204 can perform an image forming process for executing a print job according to a user's instruction.

[0019] (Communication unit 203) The communication unit 203 is composed of a communication control card such as a LAN (Local Area Network) card, and performs transmission and reception of various data with external devices connected to communication networks such as LAN and WAN (Wide Area Network). The external devices with which the communication unit 203 communicates are, for example, the control PC 113, etc.

[0020] (Storage unit 205) The storage unit 205 is composed of, for example, a non-volatile semiconductor memory (such as a flash memory), an HDD (Hard Disk Drive), or the like. The storage unit 205 non-volatily stores various programs including system programs and processing programs executed by the control unit 204, and various data necessary for the execution of these programs.

[0021] (Operation display unit 206: Display unit 206a: Operation unit 206b) The operation display unit 206 is composed of, for example, a touch panel type liquid crystal display (LCD: Liquid Crystal Display), and includes a display unit 206a and an operation unit 206b. The display unit 206a displays various information on the display screen of the UI operation panel 101 according to the display control signal from the control unit 204. The operation unit 206b is provided with various operation keys such as numeric keys and start keys, accepts various input operations performed by the user, and outputs an operation signal to the control unit 204. The operation display unit 206 is used, for example, when executing a print job or setting job information. The user can arbitrarily set required conditions such as the paper to be used, print speed information, number of printed sheets, number of print copies, print length, print weight, print diameter, etc. by operating the operation display unit 206.

[0022] (Inspection unit 207) The inspection unit 207 performs confirmation control of the printing state of the printing device. The inspection unit 207 causes the image forming apparatus 100 to print a pattern for ejection defect inspection, reads the printing result with the connection scanner device 106, and checks whether there is any ejection defect in the image forming apparatus 100. When the inspection unit 207 confirms an ejection defect, it sends information indicating the ejection defect to the control unit 204. Inspection methods for ejection defects and the like include, in addition to the method of printing an inspection pattern and reading it with a scanner, methods of directly reading a printed image with a camera or scanner for inspection, methods of monitoring the ejection status from nozzles, and various other methods. In the present embodiment, an inspection pattern is printed, and the printed inspection pattern is read with a scanner to check whether there is any ejection defect.

[0023] (Paper feeding control unit 208: Rewinding control unit 209: Fixing unit 210) The paper feeding control unit 208 controls the paper feeding of the roll paper 110 by the paper feeding device 103. The rewinding control unit 209 controls the paper discharging of the roll paper 110 by the paper discharging device 104. The fixing unit 210 controls the drying device 105 and the cooling devices 107 and 108, and fixes the ink by drying and cooling the roll paper 110 after passing through the image forming apparatus 100.

[0024] (Paper conveyance unit 201: Image forming unit 202) The paper conveyance unit 201 has a function of conveying the roll paper 110, and the image forming unit 202 actually performs a printing operation. Here, in the image forming system 200, the operation when performing an image forming process on the roll paper 110 will be described. First, the user creates print job data in an external device, performs print settings, delivery roll number settings, etc. of the print job, and transmits them to the image forming system 200 via a communication network. The control unit 204 receives the "print job data" transmitted from the external device via the communication unit 203 and the "job ticket" including print setting information, delivery roll number information, etc. of the print job. The control unit 204 starts a printing operation based on the received information. The control unit 204 drives the paper conveyance unit 201, the paper feeding control unit 208, and the rewinding control unit 209 to convey the roll paper 110 in the image forming system 200 and cause the image forming unit 202 to perform a printing operation based on the print data.

[0025] <Fig. 3: Flowchart showing the flow of the pre-execution process of the periodic cleaning> Fig. 3 is a flowchart showing the flow of the pre-execution position determination process of the periodic cleaning of the present embodiment. This flowchart is executed when the user selects a job to be printed on the UI operation panel 101 and presses the print start button. The series of processes shown in Fig. 3 are realized by the CPU of the control unit 204 of the image forming apparatus 100 reading the program stored in the storage unit 205 and expanding it into the RAM for execution. Alternatively, some or all of the functions of the steps in Fig. 3 may be realized by hardware such as an ASIC or an electronic circuit.

[0026] First, in S300, the control unit 204 reads the "accumulated printing time" at the current time from the storage unit 205 onto the RAM of the control unit 204. Further, the control unit 204 reads the "first threshold value" and the "second threshold value" used for cleaning execution determination from the storage unit 205 onto the RAM of the control unit 204. The "accumulated printing time" read onto the RAM is a temporary value used for pre-emptive execution determination of regular cleaning.

[0027] The "accumulated printing time" represents the total time (accumulated time) of the printing time since the previous cleaning. The "printing time" refers to the time required for the printing process performed based on the printing content instructed by the user. The accumulated printing time can be obtained by counting (measuring) the time required for the printing process. Specifically, the count starts when the head cap attached for ink drying prevention is separated from the print head, and the count stops when it is attached to the print head at the end of printing. Therefore, the regular time during printing and the preparation time from when printing is instructed until printing starts are not included in the accumulated printing time. Also, the time when the head cap is separated from the print head during cleaning processing etc. is not included in the accumulated printing time. The accumulated printing time is reset every time the cleaning process is executed. Also, the "first threshold value" represents the value of the accumulated printing time for performing regular cleaning. When the control unit 204 detects that the accumulated printing time has reached the first threshold value, it instructs the cleaning of the printing apparatus 102 to the image forming unit 202. For example, if it is a device that performs regular cleaning every 3 hours, the first threshold value is set to "3 hours".

[0028] The "second threshold value" is a value smaller than the first threshold value, and represents the start time of the advanced execution period that enables the advanced execution of regular cleaning. For example, when the advanced execution of regular cleaning is enabled after the cumulative printing time of "2 hours and 30 minutes", the second threshold value is "2 hours and 30 minutes". If the interval between the first threshold value and the second threshold value is shortened, the possibility of the advanced execution of regular cleaning is reduced, but since cleaning is always performed at an interval close to the "first threshold value", the ink consumption is suppressed. On the other hand, if the interval between the first threshold value and the second threshold value is lengthened, the possibility of the advanced execution of regular cleaning is increased, but there is a risk that the ink consumption will increase because cleaning may be performed considerably before the cumulative printing time reaches the first threshold value. Therefore, it is preferable to appropriately set the interval between the two threshold values according to the model and the like.

[0029] S301 and S311 in FIG. 3 indicate that the processing therebetween loops by the number of print jobs instructed by the user. In this loop, the advanced execution of regular cleaning is scheduled. In S302, the control unit 204 determines whether the cumulative printing time on the RAM is equal to or greater than the "second threshold value". If the control unit 204 determines that the cumulative printing time is equal to or greater than the "second threshold value" (Yes), it proceeds to S303, while if it determines that it is less than the second threshold value (No), it proceeds to S306. Next, in S303, the control unit 204 determines whether the previous job (hereinafter referred to as the "previous job") and the currently focused job (hereinafter referred to as the "current job") can be continuously printed. If the control unit 204 determines that continuous printing is possible (Yes), it proceeds to S306. On the other hand, if the control unit 204 determines that continuous printing is impossible and temporarily stops printing between jobs (No), it proceeds to S304. Also, when the current job is the first job, it also proceeds to S304. Here, the process of determining whether continuous printing is possible will be described with reference to FIG. 4.

[0030] <FIG. 4: A flowchart showing the flow of the process for determining whether continuous printing of jobs is possible or not> FIG. 4 is a flowchart showing the flow of a determination process for whether continuous printing of jobs is possible in the present embodiment. This flowchart is executed when determining whether the previous job and the current job can be continuously printed in S303 of FIG. 3. In S400, the control unit 204 determines whether a previous job exists, that is, whether the current job is the first job. When the control unit 204 determines that a previous job exists (Yes), it proceeds to S401, while when it determines that no previous job exists (No), it proceeds to S405. Next, in S401, the control unit 204 determines whether the paper settings of the previous job and the current job are the same. When the control unit 204 determines that the paper settings are the same (Yes), it proceeds to S402, while when it determines that the paper settings are different (No), it proceeds to S405.

[0031] Next, in S402, the control unit 204 determines whether the conveyance speed settings of the previous job and the current job are the same. When the control unit 204 determines that the conveyance speeds are the same (Yes), it proceeds to S403, while when it determines that the conveyance speeds are different (No), it proceeds to S405. Next, in S403, the control unit 204 determines whether the drying temperature settings of the previous job and the current job are the same. When the control unit 204 determines that the observed temperatures are the same (Yes), it proceeds to S404, while when it determines that the drying temperatures are different (No), it proceeds to S405.

[0032] Then, in S404, the control unit 204 determines that the previous job and the current job can be continuously printed and ends this flowchart. Also, in S405, the control unit 204 determines that the previous job and the current job cannot be continuously printed and ends this flowchart.

[0033] Returning to FIG. 3, in S304, the control unit 204 calculates the "inter-job stop time" between the current job and the previous job and executes the following determination. That is, it determines whether it is equal to or greater than the inter-job stop time of the "candidate for the execution position of the advanced periodic cleaning" (hereinafter referred to as the "current candidate"), which is a candidate for the execution position of the advanced periodic cleaning at the current time. When the control unit 204 determines that it is equal to or greater than the "inter-job stop time" of the "current candidate" (Yes), it proceeds to S305. Also, when the "current candidate" does not exist, it also proceeds to S305. On the other hand, when the control unit 204 determines that it is less than the "inter-job stop time" of the "current candidate" (No), it proceeds to S306. Note that the "inter-job stop time" is the required time when printing is stopped between jobs (between the previous job and the current job) and necessary processing is performed. The control unit 204 calculates the "inter-job stop time" by checking the device state and comparing the print settings of the two jobs.

[0034] <FIG. 5: Flowchart showing the calculation process of the inter-job stop time: FIG. 6: Table (table) associating the inter-job stop factors, necessary processing, and required time> FIG. 5 is a flowchart showing the flow of the calculation process of the inter-job stop time in the present embodiment. In this flowchart, it is executed when calculating the inter-job stop time between the previous job and the current job in S304. Also, FIG. 6 is a table showing the association between the stop factors (inter-job stop factors) of the inter-job printing stop, the necessary processing, and the required time in the present embodiment. In the present embodiment, this table is stored in the storage unit 205 in a table format and is used for calculating the inter-job stop time.

[0035] First, in S500, the control unit 204 initializes (clears) the inter-job stop time to "0". Next, in S400, the control unit 204 determines whether there is a previous job, that is, whether the current job is the first job. If the control unit 204 determines that there is a previous job (Yes), it proceeds to S401, while if it determines that there is no previous job (No), it proceeds to S501. Next, in S501, the control unit 204 adds the printing preparation time of the entire apparatus (600 in FIG. 6) to the "inter-job stop time". In the example of FIG. 6, since the inter-job stop factor is "no previous job", "2 minutes" is added to the inter-job stop time (600).

[0036] Next, in S502, the control unit 204 determines whether the roll paper 110 is set in the paper feeding device 103. If the control unit 204 determines that the roll paper 110 is set in the paper feeding device 103 (Yes), it proceeds to S504, while if it determines that the roll paper 110 is not set in the paper feeding device 103 (No), it proceeds to S503. Then, in S503, the control unit 204 adds the minimum required time (601) required for the user to set the roll paper 110 in the paper feeding device 103 to the inter-job stop time, and ends this flowchart. In the example of FIG. 6, "3 minutes", which is the required time for "paper setting", is added to the inter-job stop time.

[0037] Also, in S504, the control unit 204 determines whether the roll paper 110 that matches the paper setting of the current job is set in the paper feeding device 103. If the control unit 204 determines that the roll paper 110 that matches the paper setting of the current job is set (Yes), it ends this flowchart. On the other hand, if it determines that the roll paper 110 that matches the paper setting of the current job is not set in the paper feeding device 103 (No), it proceeds to S505. Then, in S505, the control unit 204 adds the minimum required time (602) required for the user to replace the roll paper 110 set in the paper feeding device 103 to the inter-job stop time, and ends this flowchart. In the example of FIG. 6, "6 minutes", which is the required time for "paper replacement", is added to the inter-job stop time.

[0038] On the other hand, in S401, the control unit 204 determines whether the paper settings of the previous job and the current job are the same. If the control unit 204 determines that the paper settings of the previous job and the current job are the same (Yes), it proceeds to S402. On the other hand, if it determines that the paper settings of the previous job and the current job are different (No), it proceeds to S505. Next, in S402, the control unit 204 determines whether the conveyance speed settings of the previous job and the current job are the same. If the control unit 204 determines that the conveyance speeds of the previous job and the current job are the same (Yes), it proceeds to S403. On the other hand, if it determines that the conveyance speeds of the previous job and the current job are different (No), it proceeds to S506. Then, in S506, the control unit 204 adds the conveyance speed switching time (603) required for the paper conveyance unit 201 to switch the conveyance speed to the inter-job stop time, and ends this flowchart. In the example of FIG. 6, "1 minute", which is the required time for "conveyance speed switching", is added to the inter-job stop time.

[0039] Also, in S403, the control unit 204 determines whether the drying temperature settings of the previous job and the current job are the same. If the control unit 204 determines that the drying temperature settings of the previous job and the current job are the same (Yes), it ends this flowchart. On the other hand, if it determines that the drying temperatures of the previous job and the current job are different (No), it proceeds to S507. Then, in S507, the control unit 204 adds the drying temperature switching time (604) required for the fixing unit 210 to switch the drying temperature to the inter-job stop time, and ends this flowchart. In the example of FIG. 6, "1 minute", which is the required time for "drying temperature switching", is added to the inter-job stop time.

[0040] Returning to FIG. 3, in S305, the control unit 204 executes an update process for the cleaning position candidate. That is, the control unit 204 sets the position between the current job and the previous job as the "current candidate". At this time, if the current candidate already exists, the control unit 204 sets it by overwriting. Next, in S306, the control unit 204 calculates the printing time of the current job and adds it to the cumulative printing time stored in the RAM. The printing time of the printing job can be obtained by the following formula (1) according to the job settings. For example, if the printing length of the job is "500 (m)" and the printing speed of the job is "20 (m) per minute", the printing time of the job is "25 (minutes)". "Printing time of job = (Printing length of job / Printing speed of job)" (Formula 1)

[0041] Next, in S307, the control unit 204 determines whether the cumulative printing time stored in the RAM exceeds the first threshold value. If the control unit 204 determines that the cumulative printing time exceeds the first threshold value (Yes), it proceeds to S308. On the other hand, if it determines that the cumulative printing time does not exceed the first threshold value (No), it proceeds to S311.

[0042] In S308, the control unit 204 determines whether the current candidate set in S305 exists. If the control unit 204 determines that the current candidate exists (Yes), it proceeds to S309. On the other hand, if it determines that the current candidate does not exist (No), it proceeds to S312. Next, in S309, the control unit 204 determines the current candidate as the "cleaning position candidate" at the current time and clears the current candidate. Note that when the "cleaning position candidate" is determined, the execution order and execution time information of the cleaning are determined.

[0043] Next, in S310, the control unit 204 clears the cumulative printing time on the RAM to "0". Then, in S312, the control unit 204 sends a display control signal for notifying the user of the start of printing to the display unit 206a. The display unit 206a performs display processing based on the received display control signal. At this time, the control unit 204 sends the print job and the execution order and execution time information of the cleaning determined in S309 to the display unit 206a. In response, the display unit 206a displays the print job, the execution order of the cleaning, and the execution time information. In this embodiment, the notification is made by display notification.

[0044] <Figure 7: Explanatory diagram of the print start confirmation screen displayed on the UI operation panel 101> Figure 7 is an explanatory diagram of the display screen when notifying the user of the start of printing in S312. In Figure 7, the description is made assuming a pop-up screen, but the display mode is not necessarily limited to the pop-up screen.

[0045] When notifying the user of the start of printing in S312, the UI operation panel 101 displays a print start confirmation screen 700. On the print start confirmation screen 700, the print job and the execution order and required time (701) of the cleaning determined in S309 are displayed. Also, at the bottom of the print start confirmation screen 700, an OK button 702 and a cancel button 703 are displayed, and these buttons can be pressed (touched) at all times.

[0046] In 701 of Figure 7, the print jobs and the periodic cleaning are scheduled in the order of "Print Job 0001, Print Job 0002, Periodic Cleaning, Print Job 0003, Print Job 0004", and the time required for each is displayed in association.

[0047] Returning to FIG. 3, at S313, the control unit 204 determines whether printing has started (print start OK). Specifically, the control unit 204 determines whether it has detected a pressing operation of the OK button 702 or a pressing operation of the cancel button 703. When the control unit 204 detects a pressing operation of the OK button 702 (Yes), it proceeds to S314. On the other hand, when it detects a pressing operation of the cancel button 703 (No), the process ends. That is, when the control unit 204 detects a pressing operation of the OK button 702, the control unit 204 gives a display control instruction to the display unit 206a to close the print start confirmation screen 700 and proceeds to S314. On the other hand, when the control unit 204 detects a pressing operation of the cancel button 703, the control unit 204 gives a display control instruction to the display unit 206a to close the print start confirmation screen 700 and ends this flowchart.

[0048] On the other hand, at S314, the control unit 204 gives a print instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 to execute a print sequence. In the print sequence, the print job input by the user, the cleaning execution order determined at S309, and the cleaning with the execution time information are executed.

[0049] <FIG. 8: Flowchart showing the flow of the print sequence> FIG. 8 is a flowchart showing the flow of the print sequence in the present embodiment. The processing of this flowchart is executed in the print sequence at S314 in FIG. 3. The series of processes shown in FIG. 8 is realized by the CPU of the control unit 204 of the image forming apparatus 100 reading out the program stored in the storage unit 205 and expanding and executing it in the RAM. Alternatively, some or all of the functions of the steps in FIG. 8 may be realized by hardware such as an ASIC or an electronic circuit.

[0050] S800 and S817 in FIG. 8 indicate that the process therebetween loops by the number of print jobs instructed by the user. First, in S801, the control unit 204 determines whether the current job is the first job of the printing instructed by the user. If the control unit 204 determines that the current job is the first job (Yes), it proceeds to S804. On the other hand, if it determines that the current job is the second job or later (No), it proceeds to S802. Next, in S802, the control unit 204 determines whether the previous job and the current job can be continuously printed. If the control unit 204 determines that the previous job and the current job can be continuously printed (Yes), it proceeds to S809. On the other hand, if it determines that the previous job and the current job cannot be continuously printed (No), it proceeds to S803. Note that the method for determining the possibility or impossibility of continuous printing is the same as that in S303.

[0051] Next, in S803, the control unit 204 gives a print stop instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 to stop the printing process. Next, in S804, the control unit 204 determines whether pre-execution of periodic cleaning is scheduled at a position before the current job. If the control unit 204 determines that pre-execution of periodic cleaning is scheduled (Yes), it proceeds to S805. On the other hand, if it determines that pre-execution of periodic cleaning is not scheduled (No), it proceeds to S807. Then, in S805, the control unit 204 executes cleaning of the printing apparatus 102 by instructing the image forming unit 202 to execute a cleaning process. Specifically, such cleaning is to clean a print head provided with nozzles for discharging ink (the same applies hereinafter).

[0052] Next, in S806, the control unit 204 clears the cumulative printing time stored in the storage unit 205. Next, in S807, the control unit 204 determines whether printing preparation is completed. If printing preparation is detected (Yes), the process proceeds to S808. Otherwise (No), it waits in S807. That is, when the control unit 204 detects that printing preparation is completed, the process proceeds to S808. For example, if it is the timing when the user replaces the paper, it detects that printing preparation is completed by detecting that the paper replacement is completed. Next, in S808, the control unit 204 gives a printing start instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210. Next, in S809, the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 execute the printing process. In the printing process, the paper conveyance unit 201 conveys the roll paper 110, and the image forming unit 202 controls the printing device 102 to form an image on the roll paper 110. Also, the fixing unit 210 controls the drying device 105, the cooling devices 107 and 108 to dry and cool the roll paper 110 to fix the image formation.

[0053] Next, in S810, the control unit 204 adds the printing time required for printing to the cumulative printing time stored in the storage unit 205. Next, in S811, the control unit 204 determines whether the cumulative printing time stored in the storage unit 205 is equal to or greater than the first threshold value. If the control unit 204 determines that the cumulative printing time is equal to or greater than the first threshold value (Yes), the process proceeds to S812. Otherwise, if it determines that the cumulative printing time is less than the first threshold value (No), the process proceeds to S816. In S812, the control unit 204 gives a printing stop instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 to stop the printing process.

[0054] Next, in S813, the control unit 204 instructs the image forming unit 202 to execute the cleaning process and executes the cleaning of the printing device 102. Next, in S814, the control unit 204 clears the cumulative printing time stored in the storage unit 205. Next, in S815, the control unit 204 gives a printing start instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 (printing start).

[0055] Next, in S816, the control unit 204 determines whether all the print data of the current job has been printed. If the control unit 204 determines that all the printing of the current job has been completed (Yes), the process proceeds to S817 and S818. On the other hand, if it is determined that all the printing of the current job has not been completed (No), the process proceeds to S809. Then, in S818, the control unit 204 gives a print stop instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 to stop the printing process.

[0056] <Figure 9(a): Explanatory diagram of a scheduling example of preponing regular cleaning> Figure 9(a) is a schematic explanatory diagram of a scheduling example of preponing the execution of regular cleaning in the present embodiment. The horizontally long rectangle in the drawing represents the print job instructed by the user. Also, it shows that the cumulative print time increases as it goes to the right side of the drawing, and the second threshold value and the larger first threshold value are also described. "900" indicates the position where the cumulative print time reaches the first threshold value, that is, the scheduled position for executing regular cleaning.

[0057] By the processing of the flowchart in FIG. 3, the determination is made about the job separation positions from "901" to "904". First, since the cumulative print time at the print start position 901 is less than the second threshold value, it does not become a "candidate position for preponing the execution of regular cleaning" (refer to "No" in S302). Note that it takes a print preparation time of "2 (minutes)" immediately after the start of the print start position 901 (refer to 600 in FIG. 6).

[0058] Next, between Job 1 and Job 2 at 902, although the cumulative printing time is less than the first threshold and greater than or equal to the second threshold, since continuous printing is possible and no inter-job stop occurs, it does not become a "candidate position for advancing the regular cleaning" (refer to "Yes" in S303). Next, between Job 2 and Job 3 at 903, the cumulative printing time is less than the first threshold and greater than or equal to the second threshold, and furthermore, an inter-job stop occurs, so it becomes a candidate for the position where the regular cleaning is advanced (refer to S304 and S305). Note that the inter-job stop occurs due to paper replacement, for example, a job stop of "6 (minutes)" occurs (refer to "602" in Fig. 6).

[0059] Next, between Job 3 and Job 4 at 904, the cumulative printing time is less than the first threshold and greater than or equal to the second threshold, and furthermore, an inter-job stop occurs. However, since the inter-job stop time is shorter than that of the current candidate 903, it does not become a candidate for the position where the regular cleaning is advanced (refer to "No" in S304). In this example, the inter-job stop occurs due to a drying temperature switch, and the time required for the drying temperature switch is "1 (minute)" (refer to 604 in Fig. 6), which is shorter than the "6 (minutes)" required for paper replacement. Then, during the printing of Job 4, the cumulative printing time becomes greater than or equal to the first threshold, so at this point, the candidate between Job 2 and Job 3 at 903 is determined as the position where the regular cleaning is advanced.

[0060] <Fig. 9(b): Explanation diagram of the time schedule when the scheduled printing process is executed> Fig. 9(b) is a schematic explanatory diagram of the time schedule when the printing process scheduled in Fig. 9(a) is executed. The four horizontal rectangles without patterns represent the printing jobs (Job 1 to Job 4) instructed by the user. The horizontally long rectangle with a hatched pattern represents the process where the inter-job stop position is executed. The horizontally long rectangle with a horizontal striped pattern represents the execution of cleaning.

[0061] First, after performing the printing preparation operation, Jobs 1 and 2 are printed continuously, and the printing is temporarily stopped at position 903 after Job 2 ends. Here, in parallel with the user's paper replacement operation, the pre-execution of the regular cleaning is performed (905), and the cumulative printing time is cleared. Then, Job 3 is printed and temporarily stopped to switch the drying temperature. Finally, Job 4 is printed to complete the printing process of all jobs.

[0062] As described above, in this embodiment, in a printing device that cleans a print head provided with nozzles for discharging ink and executes regular cleaning when the cumulative printing time, which is the cumulative printing time since the previous cleaning, reaches a first threshold value, the following processing is executed. That is, the control unit 204 counts the cumulative printing time obtained by accumulating the printing time (counting unit). And when there are a plurality of printable print jobs that can be continuously printed within a cumulative printing time width that is less than the first threshold value and equal to or greater than a second threshold value smaller than the first threshold value, and there is a job separation position involving printing stop, the following processing is executed. That is, the regular cleaning is executed in advance at the job separation position.

[0063] In this way, the regular cleaning is executed in advance at the separation position of the job (among which is the printing stop position such as paper replacement) within a certain range before the cumulative printing time reaches the predetermined time (905). Thereby, it is avoided that the printing is temporarily stopped during printing and the regular cleaning (900) is entered. Therefore, it is possible to suppress the ink consumption due to cleaning and to minimize the occurrence of downtime due to regular cleaning as much as possible.

[0064] Further, when there are multiple job break positions, the control unit 204 can perform the cleaning in advance at the break position with the longest inter-job stop time, or can perform the cleaning in advance at the break position where the inter-job stop time is closest to the first threshold value. For this reason, sufficient time for performing the pre-cleaning is ensured, and it is also possible to perform the pre-cleaning at a position relatively close to the regular cleaning. Further, when the cleaning is performed in advance by the control unit 204, the control unit notifies the user by displaying and notifying the execution order of each printing job and the cleaning (first notification unit), and by displaying and notifying the required time of each printing job and the cleaning (second notification unit). Therefore, the usability of the user is also improved.

[0065] <<Second Embodiment>> In the second embodiment, a mode of performing the regular cleaning in advance at the printing stop timing after all printing jobs are completed will be described with reference to FIGS. 10, 11, and 12.

[0066] <FIG. 10: Flowchart showing the flow of the pre-execution position determination process of the regular cleaning in the second embodiment> FIG. 10 is a flowchart showing the flow of the pre-execution position determination process of the regular cleaning in the second embodiment. The series of processes shown in FIG. 10 are realized by the CPU of the control unit 204 of the image forming apparatus 100 reading out the program stored in the storage unit 205 and expanding it in the RAM and executing it. Alternatively, some or all of the functions of the steps in FIG. 10 may be realized by hardware such as an ASIC or an electronic circuit. This flowchart is executed when the user selects a job to be printed on the UI operation panel 101 and presses the print start button. Note that S301 to S311 in FIG. 10 are the same processes as the steps with the same numbers in FIG. 3.

[0067] First, in S1000, the control unit 204 reads the cumulative printing time onto the RAM. Further, the control unit 204 reads the first threshold value, the second threshold value, and the third threshold value used for cleaning execution determination from the storage unit 205 onto the RAM. Here, the "third threshold value" is a value smaller than the "first threshold value" and is used for determining whether to execute the regular cleaning in advance at the position after all printing jobs are completed. For example, when the cumulative printing time is "2 hours and 40 minutes" or more at the end of all printing jobs and it is desired to execute the regular cleaning in advance, the "third threshold value" is "2 hours and 40 minutes". Note that the third threshold value may be the same as the second threshold value.

[0068] S301 and S311 indicate processes that loop the number of printing jobs instructed by the user for the processes therebetween. In S302, the control unit 204 determines whether the cumulative printing time on the RAM is equal to or greater than the second threshold value. When the control unit 204 determines that the cumulative printing time is equal to or greater than the second threshold value (Yes), it proceeds to S303. On the other hand, when it determines otherwise (No), that is, when it determines that it is less than the second threshold value, it proceeds to S306. Next, in S303, the control unit 204 determines whether the previous job and the current job can be printed continuously. When the control unit 204 determines that they can be printed continuously (Yes), it proceeds to S306. On the other hand, when the control unit 204 determines that continuous printing is impossible and printing is temporarily stopped between jobs (No), it proceeds to S304. Also, when the current job is the first job, it also proceeds to S304.

[0069] In S304, the control unit 204 calculates the inter-job stop time between the current job and the previous job and determines whether it is equal to or greater than the current candidate's inter-job stop time. When the control unit 204 determines that it is equal to or greater than the current candidate's inter-job stop time (Yes), it proceeds to S305. Also, when there is no current candidate, it also proceeds to S305. On the other hand, when the control unit 204 determines that it is less than the current candidate's inter-job stop time (No), it proceeds to S306.

[0070] In S305, the control unit 204 executes an update process for the cleaning position candidate. That is, the control unit 204 sets the position between the current job and the previous job as the "current candidate". At this time, if the current candidate already exists, the control unit 204 sets it by overwriting. Next, in S306, the control unit 204 calculates the printing time of the current job and adds it to the cumulative printing time stored in the RAM. Next, in S307, the control unit 204 determines whether the cumulative printing time stored in the RAM exceeds the first threshold. If the control unit 204 determines that the cumulative printing time exceeds the first threshold (Yes), it proceeds to S308. On the other hand, if it is determined that the cumulative printing time does not exceed the first threshold (No), it proceeds to S311.

[0071] In S308, the control unit 204 determines whether the current candidate set in S305 exists. If the control unit 204 determines that the current candidate exists (Yes), it proceeds to S309. On the other hand, if it is determined that the "current candidate" does not exist (No), it proceeds to S312. Next, in S309, the control unit 204 determines the current candidate as the "current cleaning position candidate" and clears the current candidate. Note that when the "cleaning position candidate" is determined, the execution order and execution time information of the cleaning are determined. Then, in S310, the control unit 204 clears the cumulative printing time on the RAM to "0".

[0072] Next, in S1001, the control unit 204 determines whether the cumulative printing time on the RAM is equal to or greater than the third threshold. If the control unit 204 determines that the cumulative printing time is equal to or greater than the third threshold (Yes), it proceeds to S1002. On the other hand, if it is determined that the cumulative printing time is less than the third threshold (No), it proceeds to S312. Then, in S1002, the control unit 204 schedules the execution of the advance of the regular cleaning to the position after all printing jobs are completed.

[0073] In S312, the control unit 204 sends a display control signal for notifying the user of the start of printing to the display unit 206a. The display unit 206a performs display according to the display control signal. At this time, similar to the first embodiment, the control unit 204 sends information related to the execution of cleaning inserted before the start of printing and between print jobs. However, it does not send information regarding cleaning after the end of printing. This is because cleaning is executed in parallel with the work of taking out the product, etc., so the user does not need to be conscious of the cleaning. Therefore, in S1002, the scheduled cleaning execution position and execution time are not notified (displayed and notified) to the user.

[0074] Next, in S313, the control unit 204 determines whether printing has started. Specifically, the control unit 204 determines whether it has detected a pressing operation of the OK button 702 or a pressing operation of the cancel button 703. When the control unit 204 detects a pressing operation of the OK button 702 (Yes), it proceeds to S1003. On the other hand, when it detects a pressing operation of the cancel button 703 (No), the process ends. That is, when the control unit 204 detects a pressing operation of the OK button 702, the control unit 204 gives a display control instruction to the display unit 206a to close the print start confirmation screen 700 and proceeds to S1003. On the other hand, when the control unit 204 detects a pressing operation of the cancel button 703, the control unit 204 gives a display control instruction to the display unit 206a to close the print start confirmation screen 700 and ends this flowchart.

[0075] Then, in S1003, the control unit 204 gives a print instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 to execute the print sequence. In the print sequence, the print job input by the user and the cleaning determined in S309 and S1002 are executed.

[0076] <Figure 11: Flowchart showing the flow of the print sequence in the second embodiment> FIG. 11 is a flowchart showing the flow of the printing sequence in the second embodiment. This flowchart is executed in the printing sequence in S1003. The series of processes shown in FIG. 11 is realized by the CPU of the control unit 204 of the image forming apparatus 100 reading out the program stored in the storage unit 205 and expanding and executing it in the RAM. Alternatively, some or all of the functions of the steps in FIG. 11 may be realized by hardware such as an ASIC or an electronic circuit. Note that S800 to S818 in FIG. 11 are the same processes as the steps with the same numbers in FIG. 8.

[0077] S800 and S817 in FIG. 8 indicate that the processes therebetween loop by the number of print jobs instructed by the user. In S801, the control unit 204 determines whether the current job is the first print job instructed by the user. When the control unit 204 determines that the current job is the first job (Yes), it proceeds to S804, while when it determines that the current job is the second job or later (No), it proceeds to S802. Next, in S802, the control unit 204 determines whether the previous job and the current job can be printed continuously. When the control unit 204 determines that the previous job and the current job can be printed continuously (Yes), it proceeds to S809, while when it determines that the previous job and the current job cannot be printed continuously (No), it proceeds to S803.

[0078] Next, in S803, the control unit 204 gives a print stop instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 to stop the printing process. Next, in S804, the control unit 204 determines whether pre-execution of periodic cleaning is scheduled at a position before the current job. When the control unit 204 determines that pre-execution of periodic cleaning is scheduled (Yes), it proceeds to S805, while when it determines that pre-execution of periodic cleaning is not scheduled (No), it proceeds to S807. Then, in S805, the control unit 204 executes cleaning of the printing apparatus 102 by instructing the image forming unit 202 to execute a cleaning process.

[0079] Next, in S806, the control unit 204 clears the cumulative printing time stored in the storage unit 205. Next, in S807, the control unit 204 determines whether printing preparation is completed. If printing preparation is detected (Yes), the process proceeds to S808. Otherwise (No), it waits in S807. That is, when the control unit 204 detects that printing preparation is completed, the process proceeds to S808. For example, if it is the timing when the user replaces the paper, it detects that printing preparation is completed by detecting that the paper replacement is completed. Next, in S808, the control unit 204 gives a print start instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210. Next, in S809, the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 execute the printing process.

[0080] Next, in S810, the control unit 204 adds the printing time required for printing to the cumulative printing time stored in the storage unit 205. Next, in S811, the control unit 204 determines whether the cumulative printing time stored in the storage unit 205 is equal to or greater than the first threshold. If the control unit 204 determines that the cumulative printing time is equal to or greater than the first threshold (Yes), the process proceeds to S812. Otherwise, if it determines that the cumulative printing time is less than the first threshold (No), the process proceeds to S816. Next, in S812, the control unit 204 gives a print stop instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 to stop the printing process.

[0081] Next, in S813, the control unit 204 instructs the image forming unit 202 to execute the cleaning process to clean the printing apparatus 102. Next, in S814, the control unit 204 clears the cumulative printing time stored in the storage unit 205. Next, in S815, the control unit 204 gives a print start instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 (print start).

[0082] Next, in S816, the control unit 204 determines whether all the print data of the current job has been printed. If the control unit 204 determines that all the printing of the current job has been completed (Yes), the process proceeds to S817. On the other hand, if it is determined that all the printing of the current job has not been completed (No), the process proceeds to S809. Then, in S818, the control unit 204 gives a print stop instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 to stop the printing process.

[0083] Next, in S1100, the control unit 204 determines whether pre-execution of periodic cleaning is scheduled at the position after all print jobs are completed. If the control unit 204 determines that pre-execution of periodic cleaning is scheduled at the position after all print jobs are completed, the process proceeds to S1101. On the other hand, if it is determined that pre-execution of periodic cleaning is not scheduled at the position after all print jobs are completed (No), this flowchart ends. Next, in S1101, the control unit 204 gives an execution instruction for the cleaning process to the image forming unit 202 to execute the cleaning of the printing apparatus 102. Then, in S1102, the control unit 204 clears the cumulative printing time stored in the storage unit 205.

[0084] <Figure 12(a): Explanatory diagram of an example of scheduling pre-execution of periodic cleaning in the second embodiment> Figure 12(a) is a schematic explanatory diagram of a scheduling example of preponing regular cleaning in the second embodiment. Also, it shows that the cumulative printing time increases as going to the right side of the drawing, and the second threshold value, a third threshold value larger than this, and the first threshold value are also described. 1200 indicates the position where the cumulative printing time reaches the first threshold value, that is, the scheduled position for executing regular cleaning. The horizontally long rectangle with a solid line represents the print jobs instructed by the user (Job 1, Job 2). The horizontally long rectangle with a dashed line represents the print job (next print) expected to be instructed by the user next, and at this point, the number of jobs and the delimiter position are undetermined. 1200 represents the position where the cumulative printing time reaches the first threshold value, that is, the scheduled position for executing regular cleaning, and 1201 represents the next print start position. If this embodiment is not applied, these positions become candidates for the cleaning execution position.

[0085] By the process shown in FIG. 10, determination is made for the job delimiter positions from 1202 to 1204. First, since the printing start position 1202 has a cumulative printing time less than the second threshold value, it does not become a candidate for the preponed regular cleaning execution position (see "No" in S302). Next, between Job 1 and Job 2 at 1203, since the cumulative printing time is less than the second threshold value, similar to 1202, it does not become a candidate for the preponed regular cleaning execution position (see "No" in S302). Next, the printing end position 1204 is located less than the first threshold value and greater than or equal to the third threshold value, so it is determined as the preponed regular cleaning execution position.

[0086] <FIG. 12(b): Explanatory diagram of the time schedule when the scheduled printing process is executed> Figure 12(b) is a schematic explanatory diagram of the time schedule when the printing process scheduled in FIG. 12(a) is executed. The horizontally long rectangle without a pattern represents the print jobs instructed by the user. The horizontally long rectangle with a hatched pattern represents the process executed at the job interval stop position. The rectangle with a horizontal stripe pattern represents the execution of cleaning.

[0087] First, after performing the printing preparation operation, print Job 1. After Job 1 is completed, temporarily stop the printing so that the user can replace the paper. Then, print Job 2 and all printing jobs are completed. Here, in parallel with the user's operation of taking out the finished product, perform the advance execution of the regular cleaning (1204) and clear the cumulative printing time.

[0088] As described above, in this embodiment, by performing cleaning at the printing end position within a certain range before the cumulative printing time reaches the predetermined time (1205), it is possible to avoid cleaning at the next printing start position or during the next printing. Thereby, while suppressing the ink consumption due to cleaning, it is possible to minimize the occurrence of downtime due to regular cleaning.

[0089] Also, in the second embodiment, when the control unit 204 performs the advance execution of cleaning at the end of all printing jobs, it may be configured to include a notification unit that only displays and notifies the execution order of each printing job, while not displaying and notifying the execution position of the cleaning. Similarly, when the control unit 204 performs the advance execution of cleaning at the end of all printing jobs, it may be configured to include a notification unit that only displays and notifies the printing time of each printing job, while not displaying and notifying the required time for cleaning.

[0090] As described above, in this embodiment, when the cumulative printing time counted at the end of all printing jobs is less than the first threshold and is equal to or greater than a third threshold smaller than the first threshold, the control unit 204 advances and executes the regular cleaning at the end time.

[0091] <<Embodiment 3>> The third embodiment will be described with reference to FIGS. 13 and 14 regarding the mode of advancing and executing the regular cleaning at the timing when an unexpected printing stop occurs during printing.

[0092] <FIG. 13: Flowchart showing the flow of the printing sequence in the third embodiment> FIG. 13 is a flowchart showing the flow of a printing sequence in the third embodiment. This flowchart is executed in a printing sequence when the first and second embodiments are not applied, and when the first or second embodiment is applied but the delimiter position of a job that meets the conditions cannot be found and the pre-execution of regular cleaning is not scheduled. The series of processes shown in FIG. 13 is realized by the CPU of the control unit 204 of the image forming apparatus 100 reading out the program stored in the storage unit 205 and expanding and executing it in the RAM. Alternatively, some or all of the functions of the steps in FIG. 13 may be realized by hardware such as an ASIC or an electronic circuit. Note that S800 to S803 and S807 to S818 in FIG. 13 are the same processes as the steps with the same numbers in FIG. 8.

[0093] S800 and S817 in FIG. 8 indicate that the processes therebetween loop by the number of print jobs instructed by the user. In S801, the control unit 204 determines whether the current job is the first print job instructed by the user. If the control unit 204 determines that the current job is the first job (Yes), it proceeds to S807, while if it determines that the current job is the second job or later (No), it proceeds to S802. Next, in S802, the control unit 204 determines whether the previous job and the current job can be printed continuously. If the control unit 204 determines that the previous job and the current job can be printed continuously (Yes), it proceeds to S809, while if it determines that the previous job and the current job cannot be printed continuously (No), it proceeds to S803.

[0094] Next, in S803, the control unit 204 gives a print stop instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 to stop the printing process. Next, in S807, the control unit 204 determines whether it has detected the completion of print preparation. If the control unit 204 has detected the completion of print preparation (Yes), it proceeds to S808. Otherwise (No), it enters a wait state in S807. That is, when the control unit 204 detects the completion of print preparation, it proceeds to S808. For example, if it is the timing when the user replaces the paper, the completion of print preparation is detected by detecting that the paper replacement has been completed. Next, in S808, the control unit 204 gives a print start instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210. Next, in S809, the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 execute the printing process. Next, in S810, the control unit 204 adds the printing time required for printing to the cumulative printing time stored in the storage unit 205.

[0095] Next, in S1300, the control unit 204 determines whether it has detected the occurrence of an abrupt print stop factor. If the control unit 204 has detected an abrupt print stop factor (Yes), it proceeds to S1301. Otherwise (No), it proceeds to S811. The "abrupt print stop factor" is, for example, a roll paper remaining amount shortage error that occurs when the remaining amount of the roll paper 110 is insufficient, a waste ink tank full error that occurs when the free capacity of the waste ink tank is insufficient, and the like.

[0096] Next, in S1301, the control unit 204 gives a print stop instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 to stop the printing process. Next, in S1302, the control unit 204 determines whether the cumulative printing time stored in the storage unit 205 is equal to or greater than the fourth threshold value. If the control unit 204 determines that the cumulative printing time is equal to or greater than the fourth threshold value (Yes), it proceeds to S1303. On the other hand, if it determines that the cumulative printing time is less than the fourth threshold value (No), it proceeds to S1306. The "fourth threshold value" is a value smaller than the first threshold value and is used to determine whether to perform the regular cleaning in advance at the timing when an abrupt print stop occurs during printing. For example, if it is desired to perform the regular cleaning in advance when the cumulative printing time is "2 hours and 50 minutes" or more at the time when an abrupt print stop occurs during printing, the "fourth threshold value" is "2 hours and 50 minutes". Assume that the fourth threshold value is stored in the storage unit 205. The fourth threshold value may be the same value as the second threshold value or the third threshold value.

[0097] Next, in S1303, the control unit 204 determines whether the cleaning can be executed. If it determines that the cleaning can be executed (Yes), it proceeds to S1304. On the other hand, if the control unit 204 determines that the cleaning cannot be executed (No), it enters a wait state in S1303. If the control unit 204 can determine that the cleaning can be executed, it exits S1303 and proceeds to S1304. For example, if the print stop factor is a roll paper remaining amount shortage error, the cleaning can be executed in parallel with the user's paper replacement operation, so the control unit 204 determines that the cleaning can be executed. On the other hand, if the print stop factor is a waste ink tank full error, the cleaning cannot be executed because there is no space in the waste ink tank. After the user discards the waste ink and there is space in the waste ink tank, the control unit 204 detects that the cleaning can be executed.

[0098] Next, in S1304, the control unit 204 gives an instruction to the image forming unit 202 to execute a cleaning process and executes the cleaning of the printing apparatus 102. Next, in S1305, the control unit 204 clears the cumulative printing time stored in the storage unit 205. Next, in S1306, the control unit 204 determines whether it has detected the elimination of the printing stop factor. If the control unit 204 determines that it has detected the elimination of the printing stop factor (Yes), it proceeds to S815. On the other hand, if it determines that it has not detected the elimination of the printing stop factor (No), it enters a wait state in S1306 until the elimination of the printing stop factor is detected. The elimination of the printing stop factor means, for example, in the case of a roll paper remaining amount shortage error, that the paper replacement has been completed, and in the case of a waste ink tank full error, that there is space in the waste ink tank.

[0099] On the other hand, in S811, the control unit 204 determines whether the cumulative printing time stored in the storage unit 205 has reached or exceeded the first threshold value. If the control unit 204 determines that the cumulative printing time has reached or exceeded the first threshold value (Yes), it proceeds to S812. On the other hand, if it determines that the cumulative printing time has not reached the first threshold value (No), it proceeds to S816. Next, in S812, the control unit 204 gives a printing stop instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 to stop the printing process. Next, in S813, the control unit 204 instructs the image forming unit 202 to execute a cleaning process and executes the cleaning of the printing apparatus 102. Next, in S814, the control unit 204 clears the cumulative printing time stored in the storage unit 205.

[0100] Next, in S815, the control unit 204 gives a printing start instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210. Next, in S816, the control unit 204 determines whether all the print data of the current job has been printed. If the control unit 204 determines that all the printing of the current job has been completed (Yes), it proceeds to S817. On the other hand, if it determines that all the printing of the current job has not been completed (No), it proceeds to S809. Then, in S818, the control unit 204 gives a printing stop instruction to the paper conveyance unit 201, the image forming unit 202, and the fixing unit 210 to stop the printing process.

[0101] <FIG. 14: Explanatory diagram of time schedule when printing process in the third embodiment is executed> FIG. 14 is a schematic explanatory diagram of the time schedule when the printing process in the third embodiment is executed. A horizontally long rectangle without a pattern represents a print job (Job 1, continuation of Job 1) instructed by the user. A horizontally long rectangle with a hatched pattern represents a process executed at the inter-job stop position. A horizontally long rectangle with a horizontal striped pattern represents the execution of cleaning.

[0102] 1400 represents the position where the cumulative printing time reaches the first threshold value, that is, the scheduled position for performing regular cleaning. First, Job 1 is printed after performing the printing preparation operation. At the position (1401) where the cumulative printing time during printing is equal to or greater than the fourth threshold value, a roll paper remaining amount shortage error occurs (see A), so the printing is temporarily stopped. At this time, in parallel with the user's paper replacement operation (interrupted for "6 (minutes)" in the example of FIG. 14), the regular cleaning is executed in advance (1402) to clear the cumulative printing time. Then, the continuation of Job 1 is printed and all print jobs are completed.

[0103] As described above, in the present embodiment, when a printing stop factor that causes the control unit 204 to stop printing occurs during the execution of a print job, the following process is executed. That is, when the cumulative printing time counted by the counting unit (control unit 204) at the time of occurrence of the printing stop factor is less than the first threshold value and equal to or greater than a fourth threshold value smaller than the first threshold value, the regular cleaning is executed in advance at the time of occurrence. In this way, in the third embodiment, the regular cleaning is executed in advance at the timing when the "printing stop factor" (reference sign A) occurs within a certain range before the cumulative printing time reaches a predetermined time (first threshold value) (1402). Thereby, it is possible to avoid temporarily stopping the printing during printing and entering the regular cleaning. As a result, it is possible to suppress the ink consumption due to cleaning and minimize the occurrence of downtime due to regular cleaning as much as possible.

[0104] In each of the embodiments, the image forming system 200 has been described as an example. However, the present invention can be applied to a printing device that executes periodic cleaning of a print head when the cumulative printing time, such as that of an MFP, a home or business inkjet printer, reaches a certain threshold value.

[0105] Further, the control unit 204 may use the communication unit 203 to display information such as the execution order and required time of each printing job and cleaning on the display screen of a mobile terminal such as a smartphone, a tablet terminal, or a notebook PC as shown in FIG. 7. For this purpose, a dedicated application may be downloaded and installed from a specific site on the mobile terminal, and the mobile terminal may be configured to enable short-range communication such as "Bluetooth (registered trademark)".

[0106] <Addendum> The disclosure of this embodiment includes the following configurations, methods, and programs. (Configuration 1) In a printing device configured to clean a print head provided with nozzles for ejecting ink, and execute periodic cleaning when the cumulative printing time, which is the cumulative printing time since the previous cleaning, reaches a first threshold value, a counting unit that counts the cumulative printing time obtained by accumulating the printing time; and a control unit that, when there are a plurality of printable printing jobs in a continuous printing time width in which the cumulative printing time counted by the counting unit is less than the first threshold value and is equal to or greater than a second threshold value smaller than the first threshold value, and there is a job separation position involving printing stop, executes the periodic cleaning in advance at the job separation position. A printing device characterized by comprising: (Configuration 2) The control unit further When there are a plurality of job separation positions, the printing device according to Configuration 1, characterized in that the periodic cleaning is executed in advance at the job separation position with the longest printing stop time. (Configuration 3) The control unit further The printing device according to Configuration 1, wherein when there are a plurality of job separation positions, the regular cleaning is executed in advance at the job separation position where the printing stop time is closest to the first threshold value. (Configuration 4) The plurality of printable continuous printing jobs In the plurality of printing jobs, there is a previous job that is earlier in time than the own job, and each of the paper setting, the paper conveyance speed, and the paper drying temperature is the same setting. The printing device according to Configuration 1. (Configuration 5) When the regular cleaning is executed in advance by the control unit, the printing device according to any one of Configurations 1 to 4, further comprising a first notification unit that displays and notifies the execution order of each printing job and the cleaning. (Configuration 6) When the regular cleaning is executed in advance by the control unit, the printing device according to any one of Configurations 1 to 4, further comprising a second notification unit that displays and notifies the required time for each printing job and the cleaning. (Configuration 7) The control unit further When the cumulative printing time counted by the counting unit at the end point of all printing jobs is less than the first threshold value and is equal to or greater than a third threshold value smaller than the first threshold value, the regular cleaning is executed in advance at the end point. The printing device according to Configuration 1. (Configuration 8) When the regular cleaning is executed in advance at the end point of all printing jobs by the control unit, the printing device according to Configuration 7, further comprising a third notification unit that displays and notifies only the execution order of each printing job and does not display and notify the execution position of the cleaning. (Configuration 9) When the regular cleaning is executed in advance at the end point of all printing jobs by the control unit, the printing device according to Claim 6, further comprising a fourth notification unit that displays and notifies only the printing time of each printing job and does not display and notify the required time for the cleaning. (Configuration 10) The control unit further When a printing stop factor that causes printing to stop occurs during the execution of a printing job, if the cumulative printing time counted by the counting unit at the time of occurrence of the printing stop factor is less than the first threshold value and is equal to or greater than a fourth threshold value smaller than the first threshold value, the printing device according to Configuration 1 is characterized in that the periodic cleaning is executed in advance at the time of occurrence. (Configuration 11) The printing stop factor is a roll paper remaining amount shortage error that occurs when the remaining amount of roll paper, which is a printing medium, is insufficient, or a waste ink tank full error that occurs when the free capacity of the waste ink tank is insufficient, and the printing device according to Configuration 10 is characterized in that it is such. (Method 1) A control method for a printing device that cleans a print head provided with nozzles for discharging ink, and executes periodic cleaning when the cumulative printing time obtained by accumulating the printing time since the previous cleaning reaches a first threshold value, wherein it has a counting step of counting the cumulative printing time obtained by accumulating the printing time, and when there are a plurality of printable printing jobs in a continuous printing time width in which the cumulative printing time counted in the counting step is less than the first threshold value and is equal to or greater than a second threshold value smaller than the first threshold value, and there is a job separation position accompanied by a printing stop, it has a control step of executing the periodic cleaning in advance at the job separation position, and is characterized by such. (Program 1) A program that causes a computer to execute a control method for a printing device that cleans a print head provided with nozzles for discharging ink, and executes periodic cleaning when the cumulative printing time obtained by accumulating the printing time since the previous cleaning reaches a first threshold value, wherein the control method is it has a counting step of counting the cumulative printing time obtained by accumulating the printing time, and When there are a plurality of printable print jobs that can be continuously printed within a cumulative print time width in which the cumulative print time counted by the counting process is less than the first threshold value and equal to or greater than a second threshold value smaller than the first threshold value, and there is a job separation position involving print stop, a control process of executing the periodic cleaning in advance at the job separation position, and a program characterized by having the above.

[0107] As described above, the preferred embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and various modifications and changes are possible within the scope of the gist thereof. For example, the present invention can also be realized by a process in which a program that realizes one or more functions of the above-described embodiments is supplied to a system or device via a network or a recording medium, and a processor of a computer of the system or device reads and executes the program. Further, the present invention can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

Explanation of Signs

[0108] 100 Image forming apparatus 101 UI operation panel 103 Paper feeding device 104 Paper discharging device 105 Drying device 107 Cooling device 108 Cooling device 110 Roll paper 111 Rotating shaft 112 Rotating shaft 113 Control PC 200 Image forming system 201 Paper conveyance unit 202 Image forming unit 203 Communication unit 204 Control unit 205 Storage unit 206 Operation display unit 206a Display unit 206b Operation unit 207 Inspection unit 208 Paper feeding control unit 209 Rewinding control unit 210 Fixing section

Claims

1. In a printing device configured to clean a print head provided with nozzles for ejecting ink, and to perform regular cleaning when a cumulative printing time, which is the cumulative printing time since the previous cleaning, reaches a first threshold value, a counting unit that counts the cumulative printing time obtained by accumulating the printing time; and a control unit that, when there are a plurality of printable print jobs that can be continuously printed within a cumulative printing time width in which the cumulative printing time counted by the counting unit is less than the first threshold value and equal to or greater than a second threshold value smaller than the first threshold value, and there is a job separation position involving printing stop, performs the regular cleaning in advance at the job separation position. The printing device is characterized by comprising the above.

2. The control unit further When there are a plurality of job separation positions, the printing device according to claim 1, wherein the regular cleaning is performed in advance at the job separation position with the longest printing stop time.

3. The control unit further When there are a plurality of job separation positions, the printing device according to claim 1, wherein the regular cleaning is performed in advance at the job separation position closest to the first threshold value in terms of the printing stop time.

4. The plurality of continuously printable print jobs In the plurality of print jobs, there is a previous job earlier in time than the own job, and each of the paper setting, the paper conveyance speed, and the paper drying temperature has the same setting. The printing device according to claim 1 is characterized by this.

5. When the regular cleaning is performed in advance by the control unit, the printing device according to any one of claims 1 to 4, further comprising a first notification unit that displays and notifies the execution order of each print job and the cleaning.

6. The printing device according to any one of claims 1 to 4, further comprising a second notification unit that displays and notifies the required time for each printing job and cleaning when the periodic cleaning is executed in advance by the control unit.

7. The control unit further When the cumulative printing time counted by the counting unit at the end of all printing jobs is less than the first threshold value and is equal to or greater than a third threshold value smaller than the first threshold value, the periodic cleaning is executed in advance at the end point. The printing device according to claim 1, characterized in that.

8. When the control unit executes the periodic cleaning in advance at the end of all printing jobs, the printing device further includes a third notification unit that only displays and notifies the execution order of each printing job, while not displaying and notifying the execution position of the cleaning. The printing device according to claim 7, characterized in that.

9. When the control unit executes the periodic cleaning in advance at the end of all printing jobs, the printing device further includes a fourth notification unit that only displays and notifies the printing time of each printing job, while not displaying and notifying the required time for cleaning. The printing device according to claim 6, characterized in that.

10. The control unit further When a printing stop factor that stops printing occurs during the execution of a printing job, and the cumulative printing time counted by the counting unit at the time of occurrence of the printing stop factor is less than the first threshold value and is equal to or greater than a fourth threshold value smaller than the first threshold value, the periodic cleaning is executed in advance at the time of occurrence. The printing device according to claim 1, characterized in that.

11. The printing stop factor is A roll paper remaining amount shortage error that occurs when the remaining amount of roll paper, which is a printing medium, is insufficient, or a waste ink tank full error that occurs when the free capacity of the waste ink tank is insufficient. The printing device according to claim 10, characterized in that.

12. A control method for a printing device that cleans a print head provided with nozzles for ejecting ink, and executes regular cleaning when the cumulative printing time obtained by accumulating the printing time since the previous cleaning reaches a first threshold value, a counting step of counting the cumulative printing time obtained by accumulating the printing time; and a control step of, when there are a plurality of printable print jobs that can be continuously printed within a cumulative printing time width that is less than the first threshold value and equal to or greater than a second threshold value smaller than the first threshold value counted in the counting step, and there is a job separation position involving printing stop, performing the regular cleaning in advance at the job separation position. A control method for a printing device is characterized by including these steps.

13. A program that causes a computer to execute a control method for a printing device that cleans a print head provided with nozzles for ejecting ink, and executes regular cleaning when the cumulative printing time obtained by accumulating the printing time since the previous cleaning reaches a first threshold value, wherein the control method includes a counting step of counting the cumulative printing time obtained by accumulating the printing time; and a control step of, when there are a plurality of printable print jobs that can be continuously printed within a cumulative printing time width that is less than the first threshold value and equal to or greater than a second threshold value smaller than the first threshold value counted in the counting step, and there is a job separation position involving printing stop, performing the regular cleaning in advance at the job separation position. A program is characterized by including these steps.

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