Image forming device

Abstract

To prevent overloading as much as possible and to prevent paper jams even in a paper discharge tray that does not have a sensor for detecting the paper discharge volume.SOLUTION: An image forming device according to the present invention comprises: a paper discharge tray 61; storage means 53 for storing a maximum loading limit indicating the number of sheets of paper PA that can be loaded onto the paper discharge tray 61; a printing unit 4 for printing on the paper PA; update means 51 that updates the number of printed sheets as the maximum loading limit, when a jam occurs in the paper discharge tray 61 after printing has been started by the printing unit 4, and when the number of printed sheets printed from the start of printing to just before the jam occurs is outside a predetermined threshold range; and notification means 52 that notifies that there is a risk of collision with the printed paper on the paper discharge tray 61, when the number of sheets to be printed exceeds the maximum loading limit or the maximum loading height.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus that minimizes overloading and prevents paper discharge jams even when the paper discharge tray does not have a sensor for detecting the paper discharge volume. [Background technology]

[0002] The printing device prints on the transported paper by ejecting ink from an inkjet head based on image data, and ejects the printed paper onto a paper ejection tray.

[0003] At this time, if the stacking capacity of the output tray of the printing device is exceeded, a paper jam will occur. Although it is possible to prevent paper jams by installing a sensor on the output tray to detect the paper volume, some products do not have a center to detect the paper volume in order to reduce costs. In products without a sensor to detect the paper volume, a maximum stacking capacity for the output tray is set, and printing is automatically paused when the maximum number of sheets is reached.

[0004] Patent Document 1 discloses a technology that starts counting the number of sheets loaded on the paper output tray, and when the counted number of sheets reaches the maximum number of sheets, stops the printing operation and drives and controls a maximum load warning means that notifies the operator of the load limit of the paper output tray, thereby automatically notifying the operator of the status of the paper output tray. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-118859 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technique described in Patent Document 1 has the problem that correct control cannot be performed if the user does not know the thickness of the paper, and that setting the paper thickness is troublesome.

[0007] The present invention has been made in consideration of the above problems, and aims to provide an image forming apparatus that minimizes overloading and prevents paper discharge jams even when the paper discharge tray does not have a sensor for detecting the paper discharge capacity. [Means for solving the problem]

[0008] In order to achieve the above object, the image forming apparatus according to the present invention is characterized by: A paper output tray; a storage means for storing a stack limit number indicating the maximum number of sheets of media that can be stacked on the paper ejection tray; a printing means for printing on the medium; The printer is provided with an updating means for updating the number of printed sheets as the stack limit number when a jam occurs on the paper discharge tray after printing is started by the printing means and the number of printed sheets printed from the start of printing until just before the jam occurs is outside the range of a predetermined reference value. [Effects of the Invention]

[0009] According to the features of the image forming apparatus of the present invention, even if the paper output tray does not have a sensor for detecting the paper output volume, it is possible to minimize the occurrence of an overloaded situation and prevent paper output jams. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of an inkjet printing apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing the configuration of a control system of the inkjet printing apparatus according to the embodiment of the present invention. [Figure 3](a) shows an example of a case where a large amount of printing is attempted at once, (b) shows an example of a case where the maximum number of sheets that can be loaded is increased, and (c) shows an example of a case where printing is performed continuously. [Figure 4] 10A shows an example of a case where the same owner (user) executes jobs consecutively, and FIG. 10B shows an example of a case where papers of different thicknesses are mixed. [Figure 5A] 3 is a flowchart showing the processing content of the inkjet printing apparatus 1 according to the embodiment of the present invention. [Figure 5B] 3 is a flowchart showing the processing content of the inkjet printing apparatus 1 according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or equivalent parts and components are designated by the same or equivalent reference numerals throughout the drawings. However, it should be noted that the drawings are schematic and may differ from the actual product. Furthermore, the drawings may include parts with different dimensional relationships and ratios.

[0012] Furthermore, the embodiments shown below are merely examples of devices that embody the technical concept of the present invention, and the technical concept of the present invention does not limit the arrangement of each component to that shown below. Various modifications can be made to the technical concept of the present invention within the scope of the claims.

[0013] <Configuration of inkjet printing device 1> An embodiment of an inkjet printing apparatus 1 to which an image forming apparatus according to the present invention is applied will be described in detail below with reference to the accompanying drawings.

[0014] FIG. 1 is a schematic diagram of an inkjet printing apparatus 1 according to an embodiment of the present invention, and FIG. 2 is a block diagram showing the configuration of a control system of the inkjet printing apparatus shown in FIG.

[0015] In the following description, the front side of the paper in FIG. 1 where the user is positioned is referred to as the right side, and the back side of the paper is referred to as the left side. Also, in FIG. 1, up and down as seen from the user are referred to as the up and down direction. Also, the path indicated by the dashed line in FIG. 1 is the transport path R along which paper PA, which is the print medium, is transported. The transport direction of paper PA is referred to as the front-to-rear direction. In the following description, upstream means the forward direction, and downstream means the backward direction.

[0016] As shown in FIGS. 1 and 2, the inkjet printing apparatus 1 includes a paper feed unit 2, a suction transport unit 3, a printing unit 4, a device control unit 5, a paper discharge unit 6, an operation panel unit 7, and the like.

[0017] The paper feed unit 2 feeds paper PA, which is a print medium, and includes a paper feed tray 11, a paper feed roller 12, and a registration roller 13.

[0018] The paper feed tray 11 is loaded with paper sheets PA to be used for printing.

[0019] The paper feed roller 12 picks up the paper PA stacked on the paper feed tray 11 one by one and transports the paper PA toward the registration roller 13. The paper feed roller 12 is disposed above the paper feed tray 11. The paper feed roller 12 is driven to rotate by a motor (not shown).

[0020] The registration rollers 13 temporarily stop the sheet PA conveyed by the sheet feed rollers 12, and then convey the sheet PA toward the suction conveyance section 3. The registration rollers 13 are disposed downstream of the sheet feed rollers 12.

[0021] The suction conveyance unit 3 conveys the paper PA conveyed from the registration rollers 13 toward the printing unit 4 and the paper discharge unit 6. The suction conveyance unit 3 includes a conveyor belt 21, a drive roller 22, driven rollers 23 to 25, a belt drive motor 26, a platen plate 27, and a suction fan 28.

[0022] The conveyor belt 21 is an endless belt that is looped around a drive roller 22 and driven rollers 23 to 25. The conveyor belt 21 has air intake holes, which are through holes for attracting and holding the paper sheets PA, formed at predetermined intervals along the conveying direction of the conveyor belt 21. The conveyor belt 21 attracts and holds the paper sheets PA on the conveyor belt 21 by a negative pressure (attractive force) generated in the air intake holes by driving the suction fan 28.

[0023] 1 by the rotational drive of the drive roller 22. As a result, the conveyor belt 21 moves endlessly to convey the paper PA to the right.

[0024] The conveyor belt 21 is stretched around the drive roller 22 and the driven rollers 23 to 25. The drive roller 22 is driven to rotate by a belt drive motor 26, causing the conveyor belt 21 to rotate. The driven rollers 23 to 25 are driven by the drive roller 22 via the conveyor belt 21. The driven roller 23 is disposed at approximately the same height as the drive roller 22, and spaced a predetermined distance from the drive roller 22 in the front-to-rear direction. The driven rollers 24 and 25 are disposed below the drive roller 22 and the driven roller 23, spaced a predetermined distance from each other in the front-to-rear direction, and at approximately the same height.

[0025] The belt drive motor 26 drives the drive roller 22 to rotate.

[0026] The platen plate 27 is disposed below the conveyor belt 21 between the drive roller 22 and the driven roller 23, and supports the lower surface of the conveyor belt 21 so that it can slide.

[0027] The suction fan 28 is disposed below the platen plate 27 and generates a downward airflow.

[0028] The printing unit 4 prints on the paper PA transported by the suction transport unit 3. The printing unit 4 is provided above the suction transport unit 3. The printing unit 4 includes inkjet heads 31K, 31C, 31M, and 31Y for black (K), cyan (C), magenta (M), and yellow (Y), a head holder 32, and a sensor 33.

[0029] Inkjet heads 31K, 31C, 31M, and 31Y have multiple nozzles at their bottoms, and print by ejecting ink from the nozzles onto paper PA that is transported while being sucked by suction transport unit 3. The nozzles form a nozzle row that is linearly arranged in the left-right direction (main scanning direction).

[0030] The head holder 32 holds the inkjet head 31 above the suction transport unit 3 .

[0031] The sensor 33 is made up of a CIS (Contact Image Sensor) which is a line sensor, and outputs a signal for detecting the position of the paper PA conveyed by the suction conveyance unit 3 in the left-right direction (main scanning direction).

[0032] The paper discharge unit 6 has a paper discharge tray 61. Paper sheets PA printed by the printing unit 4 are discharged and placed on the paper discharge tray 61. If the stacking capacity of this paper discharge tray 61 is exceeded, newly printed paper sheets PA will collide with the paper sheets PA already placed thereon, causing a paper discharge jam. For this reason, the maximum number of sheets of paper PA that can be stacked on the paper discharge tray 61 is set in advance as a stacking limit, and the paper sheets PA are discharged so that the number of sheets does not exceed the stacking limit.

[0033] The operation panel unit 7 includes an input unit such as a numeric keypad, a display unit, and the like, and accepts input operations by the user and displays the input results, the operating status of the inkjet printing device 1, and the like.

[0034] The device control unit 5 is configured with, for example, a CPU, RAM, ROM, hard disk, etc., and executes printing processing by controlling the operations of the paper feed unit 2, suction conveyance unit 3, printing unit 4, and paper discharge unit 6. In addition, the device control unit 5 functionally includes an update means 51, a notification means 52, and a storage means 53.

[0035] If a jam occurs on the paper output tray 61 after printing has started by the printing unit 4, and if the number of printed sheets printed from the start of printing until just before the jam occurs is outside the range of a predetermined reference value, the updating means 51 updates the number of printed sheets as the stack limit. Note that if the stack limit is updated multiple times for paper PA of the same size and thickness, the updating means 51 may determine that the paper quality setting, etc. is inappropriate and return the stack limit to the default value.

[0036] The notification means 52 notifies the user that there is a risk of collision with printed sheets on the paper discharge tray 61 if the number of sheets to be printed from now exceeds the maximum number of sheets or the maximum height of the stack.

[0037] The storage means 53 is configured by, for example, a hard disk drive, and stores the maximum number of sheets that can be loaded.

[0038] 3 and 4 are explanatory diagrams schematically illustrating the processing by the update unit 51 of the inkjet printing apparatus 1 according to an embodiment of the present invention. FIG. 3(a) shows an example of a case where a large number of print jobs are attempted at once, FIG. 3(b) shows an example of an increase in the stacking limit, FIG. 3(c) shows an example of a case where continuous printing is performed, FIG. 4(a) shows an example of a case where the same owner (user) executes consecutive jobs, and FIG. 4(b) shows an example of a case where paper of different thicknesses is mixed. Note that the default stacking limit is set to 1,000 sheets (equivalent to a stacking height of approximately 110 mm) for standard-thickness paper PA, 733 sheets (equivalent to a stacking height of approximately 109 mm) for thick paper, and 611 sheets (equivalent to a stacking height of approximately 109 mm) for postcards.

[0039] When a jam occurs on the paper output tray 61, the updating means 51 determines that a collision has occurred with printed paper if the total number of sheets printed this time is 90% or more of the load limit. Also, if the total number of sheets printed this time is less than 90% of the load limit, the updating means 51 determines that a normal paper output jam has occurred.

[0040] In the example shown in Figure 3(a), the paper PA is of standard thickness, and the number of sheets to be printed based on the copy or job is scheduled to be 2000. In this case, the total number of sheets printed this time was 999, which printed normally, but a paper ejection jam occurred at the 1000th sheet.

[0041] Since the total number of sheets printed this time, 999 sheets, is more than 90% of the maximum number of sheets that can be loaded, 1000 sheets, the update means 51 determines that a collision has occurred with printed paper and updates the maximum number of sheets that can be loaded to 999 sheets, the number of sheets that have been printed.

[0042] In the example shown in Figure 3(b), the paper PA is of standard thickness, and the number of sheets to be printed based on the copy or job is scheduled to be 2000. In this case, the total number of sheets printed this time was 1050, which exceeds the stack limit of 1000 sheets, and the printer printed successfully, but an ejection jam occurred on the 1051st sheet.

[0043] The total number of sheets printed this time, 1050, is more than 90% of the loading limit of 1000 sheets, so the updating means 51 determines that a collision has occurred with printed paper and updates the loading limit to 1050 sheets, which is the number of printed sheets. Although this exceeds the loading limit of 1000 sheets, because there is a record of paper passing through, the number is updated to 1050 sheets, which is an increase.

[0044] In the example shown in Figure 3(c), the paper PA is of standard thickness, the number of sheets to be printed based on copy A01 is planned to be 500, and the number of sheets to be printed based on copy A02 is planned to be 600 immediately after printing of copy A01 is completed.

[0045] After completing printing of 500 sheets, which is the total number of sheets based on copy A01, the printer normally prints up to 499 sheets, which is the total number of sheets based on copy A02, but a paper discharge jam occurs at the 500th sheet.

[0046] Here, after the total number of sheets printed based on copy A01, 500, was completed, printing based on the next copy A02 began within one minute, so it can be inferred that the printed paper PA was not removed from the paper output tray 61 when printing based on copy A02 began.

[0047] Therefore, the total number of sheets printed based on copy A02, 499 sheets, is added to the total number of sheets printed based on copy A01, 500 sheets. Then, since the added total number of sheets printed, 999 sheets, is more than 90% of the loading limit of 1000 sheets, updating means 51 determines that a collision has occurred with printed paper, and updates the loading limit to 999 sheets, the number of printed sheets.

[0048] In the example shown in Figure 4(a), the paper PA is of standard thickness, and the planned number of sheets to be printed based on job B01 is 500. After printing of job B01 is completed, the planned number of sheets to be printed based on job B02 by the same owner as job B01 is 600.

[0049] After completing printing of 500 sheets, which is the total number of sheets based on job B01, printing proceeds normally up to 499 sheets, which is the total number of sheets based on job B02, but a paper discharge jam occurs at the 500th sheet.

[0050] Here, after completing the printing of 500 sheets based on job B01, printing based on copy A02 has begun by the same owner as job B01, so it can be assumed that the owner will carry out printing based on job B02 without removing the printed paper PA based on job B01 from the paper output tray 61.

[0051] Therefore, the total number of sheets printed based on job B02, 499 sheets, is added to the total number of sheets printed based on job B01, 500 sheets. Then, since the added total number of sheets printed, 999 sheets, is more than 90% of the loading limit of 1000 sheets, the updating means 51 determines that a collision has occurred with printed paper PA, and updates the loading limit to 999 sheets, the number of printed sheets.

[0052] In the example shown in Figure 4(b), the planned number of prints is 900 sheets based on copy C01, whose paper PA is A3 standard thickness, and after printing of copy C01 is completed, the planned number of prints is 100 sheets based on copy C02, whose paper PA is A3 cardboard.

[0053] At this time, update means 51 calculates the stacking height from the thickness and number of sheets of paper PA. In this case, the number of sheets printed based on copy C01 is 900, so when printing based on copy C01 is complete, the stacking height will be 99 mm (= 0.11 mm x 900 sheets). The number of sheets printed based on copy C02 is 100, so when printing based on copy C01 is complete, the stacking height will be 15 mm (= 0.15 mm x 100 sheets), and adding these together will exceed the stacking height limit of 110 mm.

[0054] Therefore, the notification means 52 notifies the user that the number of sheets to be printed will exceed the stacking limit height, and that there is a risk of collision with printed sheets on the paper discharge tray 61.

[0055] 5A and 5B are flowcharts showing the processing contents in the inkjet printing apparatus 1 according to the embodiment of the present invention.

[0056] As shown in FIG. 5A, in step S101, the update means 51 determines whether or not there is a job.

[0057] If a job exists (step S101; YES), in step S101, the update means 51 determines whether the owner name of the previous job and the owner name of the current job are the same.

[0058] If the owner is the same (step S103; YES), in step S107, the update means 51 updates the number of printed sheets with the stored value.

[0059] If the owner is different (step S103; NO), in step S105, the update means 51 determines whether the previous paper passing was completed one minute ago.

[0060] If the previous paper passing was completed one minute ago (step S105; YES), in step S107, the updating means 51 updates the number of printed sheets with the stored value.

[0061] If one minute or more has passed since the previous paper feed (step S105; NO), in step S109, the update means 51 clears the number of printed sheets to zero.

[0062] In step S111, the update unit 51 determines whether the number of sheets to be printed exceeds the stack limit number of sheets or whether the stack height of sheets to be printed exceeds the stack limit height.

[0063] If the number of sheets to be printed exceeds the stacking limit or the stacking height of the sheets to be printed exceeds the stacking limit height (step S111; YES), in step S113, a notification is issued that there is a risk of collision with printed sheets on the paper output tray 61.

[0064] In step S115, the device control unit 5 executes the printing operation.

[0065] In step S117, the updating means 51 determines whether or not a paper discharge jam has occurred.

[0066] If a paper discharge jam has occurred (step S117; YES), in step S119, the update means 51 determines whether the current number of printed sheets is 90% or more of the stack limit number of sheets.

[0067] If the current number of printed sheets is less than 90% of the stack limit number of sheets (step S119; NO), the update means 51 issues a paper discharge jam error in step S127.

[0068] On the other hand, if the current number of printed sheets is 90% or more of the load limit (step S119; YES), in step S121, the update means 51 determines whether the current paper type and size has been printed three or more times and has reached 90% or more of the load limit.

[0069] If the current paper type and size is used three or more times and the number of sheets exceeds 90% of the load limit (step S121; YES), in step S125, the update means 51 resets the load limit to the default value.

[0070] On the other hand, if it has been determined that the current paper type and size is at 90% or more of the load limit less than three times (step S121; NO), in step S123, the update means 51 updates the load limit with the number of sheets printed, i.e., the current number of sheets that have been printed.

[0071] If no paper discharge jam has occurred (step S117; NO), then in step S129, the update means 51 increments the count of the number of printed sheets for each paper type.

[0072] In step S131, the update means 51 determines whether or not there are any remaining prints.

[0073] If there are no remaining sheets to be printed (step S131; NO), in step S133, the device control unit 5 determines whether or not the job has been printed.

[0074] If the job has not been printed (step S133; NO), the device control unit 5 stores the time when the printing has been completed in the storage unit 53.

[0075] If the job has been printed (step S133; YES), the device control unit 5 stores in the storage unit 53 the owner name of the job that has been printed and the number of jobs.

[0076] (Addendum) The present application discloses the following inventions.

[0077] (Appendix 1) A paper output tray; a storage means for storing a stack limit number indicating the maximum number of sheets of media that can be stacked on the paper ejection tray; a printing means for printing on the medium; an updating means for updating the number of printed sheets as the stack limit number when a jam occurs on the paper output tray after printing has started by the printing means and the number of printed sheets printed from the start of printing until just before the jam occurs is outside a range of a predetermined reference value; An image forming apparatus comprising:

[0078] This means that there is no sensor on the output tray to detect the paper output capacity, and even without setting the paper thickness, the maximum number of sheets that can be loaded is predicted based on past paper output jam occurrences, and printing will stop at the predicted number of sheets unless the paper settings are changed, preventing overloading. [Explanation of symbols]

[0079] 1. Inkjet printing device 2 Paper feed section 3. Suction and transport section 4 Printing Department 5. Equipment control section 6 Paper output section 7 Operation panel 51 Update method 52 Means of Notification 53 Memory means 61 Paper receiving tray

Claims

[Claim 1] A paper output tray; a storage means for storing a stack limit number indicating the maximum number of sheets of media that can be stacked on the paper ejection tray; a printing means for printing on the medium; an updating means for updating the number of printed sheets as the stack limit number when a jam occurs on the paper output tray after printing has started by the printing means and the number of printed sheets printed from the start of printing until just before the jam occurs is outside a range of a predetermined reference value; An image forming apparatus comprising:

Images