Image forming apparatus

Abstract

To provide an image forming apparatus capable of adding a printed page with printing quality issues to a recovery printing target.SOLUTION: An image forming apparatus includes: roll-shaped medium holding means that holds a roll-shaped medium having a plurality of labels provided at predetermined intervals; continuous sheet detection means that detects the presence or absence of a continuous sheet drawn from the held roll-shaped medium; a first sensor that detects label intervals between respective labels on the continuous sheet; first sensor control means that records data of each label interval detected by the first sensor together with identification information of a printed page that has passed through a fixing unit at the timing when each label interval was detected, and determines variations in each label interval corresponding to a predetermined amount of transport performed after the roll-shaped medium reaches its end and the continuous sheet detection means stops detecting the continuous sheet; and image forming control means that sets the pages following the printed page recorded corresponding to the varied label interval as targets for recovery printing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an image forming apparatus, and can be applied to, for example, an image forming apparatus such as a printer that prints on a long medium (roll paper) such as a die-cut label. [Background technology]

[0002] BACKGROUND ART Conventionally, in image forming devices that use roll paper, such as printers, a configuration is known that includes a roll paper feeder unit that supplies roll paper to the main body that performs printing (see, for example, Patent Document 1).

[0003] Figure 13(A) shows the schematic configuration of a conventional roll paper feeder unit. As shown in Figure 13(A), the roll paper feeder unit 2 has a tension bar B that applies back tension T to the roll paper U, and a roll paper folder F that can rotate around the roll paper U.

[0004] In this roll paper feeder unit 2, when there is sufficient remaining roll paper U and it is wound around the core, the roll paper folder F rotates in the winding direction A, and back tension T is applied from the tension bar B, which is the contact point with the roll paper U.

[0005] However, if the end of the roll paper U reaches its terminal end and comes off the core, as shown in Figure 13(B), the roll paper U will no longer come into contact with the tension bar B, and back tension T will no longer be applied. At this time, the feed speed of the roll paper U will increase because back tension T is no longer being applied, which may result in image stretching. Also, if the end of the roll paper is taped to the core, feed may pause temporarily until the tape is removed, which may result in image shrinkage. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-69521 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in conventional image forming devices, it is not possible to detect that the roll paper has reached the end of its life until it is detected that the roll paper has run out, and printing continues even after back tension is no longer being applied to the roll paper.

[0008] This causes a problem in that the pages with the above-mentioned print quality problems are marked as printed pages and are excluded from the recovery printing.

[0009] Therefore, there is a demand for an image forming apparatus that can add print pages with print quality problems to the targets of recovery printing. [Means for solving the problem]

[0010] The present disclosure comprises a rolled medium holding means for holding a rolled medium having a plurality of labels provided at predetermined intervals; a continuous paper detection means for detecting the presence or absence of continuous paper pulled out from the rolled medium held by the rolled medium holding means; a first sensor for detecting the label interval, which is the predetermined interval between each label on the continuous paper; a first sensor control means for recording data on each label interval detected by the first sensor together with identification information of the printed page that passed through a fixing unit at the timing when each label interval was detected, and for determining a fluctuation in each label interval for a predetermined amount transported after the end of the rolled medium is reached and the continuous paper detection means no longer detects the continuous paper; and an image formation control means for performing recovery printing on pages subsequent to the printed page recorded in accordance with the fluctuating label interval by the first sensor control means. [Effects of the Invention]

[0011] According to the present disclosure, print pages with print quality problems can be added to the list of pages to be subjected to recovery printing. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram showing an outline of the overall configuration of a printer according to a first embodiment. [Figure 2] FIG. 2 is a diagram showing the configuration of an IN3 transmission sensor and an IN3 reflection sensor according to the first embodiment. [Figure 3] FIG. 2 is a block diagram showing the configuration of a control system of the printer according to the first embodiment. [Figure 4] 1 is an enlarged view showing a configuration of a part of a printer according to a first embodiment. [Figure 5] 1 is a flowchart (part 1) showing a characteristic operation of the printer according to the first embodiment. [Figure 6] 10 is a flowchart (part 2) illustrating a characteristic operation of the printer according to the first embodiment. [Figure 7] 10 is a flowchart (part 3) illustrating a characteristic operation of the printer according to the first embodiment. [Figure 8] 10 is a flowchart (part 4) illustrating a characteristic operation of the printer according to the first embodiment. [Figure 9] 10 is a flowchart (part 1) showing a characteristic operation of a printer according to a second embodiment. [Figure 10] 10 is a flowchart (part 2) illustrating a characteristic operation of the printer according to the second embodiment. [Figure 11] 10 is a flowchart (part 3) illustrating a characteristic operation of the printer according to the second embodiment. [Figure 12] 10 is a flowchart (part 4) illustrating a characteristic operation of the printer according to the second embodiment. [Figure 13] FIG. 10 is an explanatory diagram showing the schematic configuration of a conventional roll paper feeder unit. DETAILED DESCRIPTION OF THE INVENTION

[0013] (A) First embodiment A first embodiment of an image forming apparatus according to the present disclosure will be described below in detail with reference to the drawings. In the following, an example in which the image forming apparatus according to the present disclosure is applied to a printer will be described.

[0014] (A-1) Configuration of the First Embodiment FIG. 1 is a diagram showing an outline of the overall configuration of a printer according to the first embodiment.

[0015] 1, printer 1 is a printer that performs electrophotographic printing on continuous paper P drawn from roll paper 202, and has a printing unit 20 that forms an image on the continuous paper P, and a feeder unit 10 that supplies the continuous paper P to this printing unit 20. Note that in the first embodiment, it is assumed that the roll paper 202 (continuous paper P) is a die-cut label medium.

[0016] <Feeder unit> The feeder unit 10 is attached to the lower front of the printing unit 20, and includes a roll paper folder 203 as a roll medium holding means, a tension bar 204, feeder transport rollers 205-1 and 205-2, a feeder transport motor 206, a winding motor 207, and a paper end sensor 208 as a continuous paper detection means. Also provided within the feeder unit 10 is a transport path R1 that connects the feeder unit 10 and the printing unit 20.

[0017] The roll paper folder 203 is located at the front end of the feeder unit 10 and rotatably holds the rolled paper 202. The roll paper folder 203 is driven by a winding motor 207 in the direction in which the roll paper 202 is wound up, so that the roll paper 202 abuts against the tension bar 204 during paper feeding.

[0018] The tension bar 204 is configured to move freely with a constant tension in order to keep the tension of the continuous paper P pulled out from the roll paper 202 constant.

[0019] The paper end sensor 208 detects the presence or absence of continuous paper P being supplied to the printing unit 20, and any abnormalities in conveyance.

[0020] The feeder transport rollers 205-1 and 205-2 are driven by a feeder transport motor 206 to transport the continuous paper P along the transport path R1 and supply the continuous paper P to the printing unit 20.

[0021] <Printing unit> Within the printing unit 20, a transport path R2 is provided, extending from the lower front surface to the lower rear surface. The front end of this transport path R2 is connected to the transport path R1 of the feeder unit 10, and the rear end is connected to a paper discharge port 250 provided on the rear surface of the printing unit 20. Within the printing unit 20, along this transport path R2, an IN1 sensor 227, an IN2 sensor 228, an IN3 lever sensor 229, an IN3 transmission sensor 230 as a first sensor, an IN3 reflection sensor 231 as a second sensor, an image forming unit 30, a pre-fixing slack sensor 232, a fixing unit 235, a fixing EXIT sensor 233, and an EXIT sensor 234 are provided in this order from upstream in the paper transport direction. Furthermore, within the printing unit 20, transport rollers 225 (225-1 to 225-3) and discharge rollers 226 are provided along this transport path R2.

[0022] The transport rollers 225 (225-1 to 225-3) are driven by a transport motor 211, and transport the continuous paper P supplied from the feeder unit 10 to the image forming unit 30 and the fixing unit 235 along the transport path R2.

[0023] An IN1 sensor 227, an IN2 sensor 228, and an IN3 lever sensor 229 detect the presence or absence of continuous paper P passing through the transport path R2, transport abnormalities, and the like.

[0024] The IN3 transmissive sensor 230 detects the label edge when printing on the continuous paper P (die-cut label medium).

[0025] The IN3 reflection sensor 231 detects the black mark edge when printing on the continuous paper P (medium with black marks).

[0026] The image forming unit 30 includes toner drum units 215 (215Y, 215M, 215C, 215K, and 215W), an intermediate transfer belt 222 as an intermediate transfer member, and a secondary transfer roller 223.

[0027] Each toner drum unit 215 transfers a developer image (hereinafter also referred to as a "toner image") developed with toner of each color onto the surface of the continuous paper P transported along transport path R2, thereby forming an image on the continuous paper P. In the first embodiment, the image forming unit 30 uses a secondary transfer method in which the toner image formed on each toner drum unit 215 is primarily transferred to the intermediate transfer belt 222, and then secondarily transferred from this intermediate transfer belt 222 to the continuous paper P.

[0028] In the first embodiment, image forming unit 30 has toner drum units 215 (215Y, 215M, 215C, 215K, 215W) corresponding to the respective colors of yellow (Y), magenta (M), cyan (C), black (K), and white (W). Each toner drum unit 215 includes components such as an LED head 216 as an exposure device and a primary transfer roller 217 that transfers a toner image onto intermediate transfer belt 222, and stacks the toner images on intermediate transfer belt 222 without misalignment.

[0029] The intermediate transfer belt 222 is rotated by the drive of the belt motor 212 and conveys the toner image to the secondary transfer roller 223 .

[0030] Secondary transfer roller 223 can come into contact with and separate from backup roller 214a across intermediate transfer belt 222. When the toner image on intermediate transfer belt 222 passes through backup roller 214a, a secondary transfer bias is applied to secondary transfer roller 223 from a high-voltage supply unit (not shown), so that the toner image is transferred to continuous paper P.

[0031] The pre-fixing slack sensor 232 detects the presence or absence of the continuous paper P onto which the toner image has been transferred, conveyance abnormalities, and the like.

[0032] The fixing unit 235 includes a heating belt 236 that heats the toner image, and a fixing backup roller 237 that sandwiches and presses the continuous paper P together with the heating belt 236. The heating belt 236 rotates by a fixing motor 214 to fix the toner image while conveying the continuous paper P.

[0033] After the continuous paper P is fixed by the fixing unit 235, it is conveyed to a discharge roller 226 that is rotationally driven by a fixing motor 214, passes through a fixing EXIT sensor 233 and an EXIT sensor 234, and is discharged out of the printer 1 from a paper discharge port 250.

[0034] <Configuration of IN3 Transmission Sensor and IN3 Reflection Sensor> FIG. 2 is a configuration diagram showing the configuration of an IN3 transmission sensor and an IN3 reflection sensor according to the first embodiment. In FIG. 2(A), the configuration of the IN3 transmission sensor 230 is shown, and in FIG. 2(B), the configuration of the IN3 reflection sensor 231 is shown.

[0035] First, the media detected by the IN3 transmission sensor 230 and the IN3 transmission sensor 230 will be described. In the first embodiment, the media detected by the IN3 transmission sensor 230 and the IN3 transmission sensor 230 is a die-cut label medium (continuous paper P). In the continuous paper P, a plurality of labels 304 (304-1 to 304-n) are attached at regular intervals on the surface (the printed surface) of the backing sheet 303. Also, a black mark 305 is attached near the tip of each label 304 on the back surface of the backing sheet 303.

[0036] The IN3 transmission sensor 230 includes a light-emitting unit 301 and a light-receiving unit 302, and is configured so that the light-receiving unit 302 receives the transmitted light emitted by the light-emitting unit 301. The continuous paper P passes between the light-emitting unit 301 and the light-receiving unit 302. Because the continuous paper P is a die-cut label medium, the IN3 transmission sensor 230 detects the amount of transmitted light that changes depending on the difference in transmittance between the label 304 (the label 304 on the backing paper 303) and the backing paper 303.

[0037] The IN3 reflection sensor 231 includes a light-emitting unit 311, a light-receiving unit 312, and a reflector 313, and is configured such that light emitted by the light-emitting unit 311 is reflected by the reflector 313 and the reflected light is received by the light-receiving unit 312. The continuous paper P passes between the light-emitting unit 311, the light-receiving unit 312, and the reflector 313. The continuous paper P includes a black mark 305, and the IN3 reflection sensor 231 detects light blocking by the black mark 305.

[0038] <Control system configuration> Next, we will explain the configuration of the control system of the printer 1. Figure 3 is a block diagram showing the configuration of the control system of the printer according to the first embodiment.

[0039] 3, printer 1 has a printer control unit 400 as an image formation control unit, a panel control unit 401, a paper management unit 402, a sensor control unit 403, and a print job receiving unit 404. Printer control unit 400 and the like read out various programs stored in a storage unit (not shown) into a memory (not shown) and executes them, thereby operating as functional units corresponding to the various programs.

[0040] A print job receiving unit 404 receives print instructions and other operation instruction commands from a higher-level host (not shown), and notifies the printer control unit 400 of the commands one by one.

[0041] The printer control unit 400 controls the main functions of the printer 1 , and issues control instructions to the panel control unit 401 , paper management unit 402 , sensor control unit 403 , and print job receiving unit 404 .

[0042] When the printer control unit 400 of the first embodiment detects that it has run out of paper, it issues a notification urging the user to check the print quality from the final printed page to the printed page where the IN3 transmissive sensor control unit 403a (described later) has detected that variations in label spacing, etc., have exceeded the acceptable range for print quality, and has the function of adding the pages for which the user is prompted to check to the list of pages to be subject to recovery printing at the user's option. This function allows the user to add printed pages that are determined to have print quality problems to the list of pages to be subject to recovery, thereby improving print quality compared to conventional methods.

[0043] Panel control unit 401 displays information on a display unit (panel) (not shown) in response to an instruction from printer control unit 400. For example, when panel control unit 401 receives an instruction from printer control unit 400 to display that a paper is out, it displays that information on the panel.

[0044] The paper management unit 402 includes a paper position management unit 402a and a paper transport control unit 402b.

[0045] The paper position management unit 402a manages information related to the print medium, such as the ID of the print page when it has completely passed the fixing EXIT sensor 233 during label interval recording measured by the IN3 transmission sensor control unit 403a (described later).

[0046] The paper transport control unit 402b controls the rotational drive of each motor (such as the feeder transport motor 206) and controls the feeding of the roll paper 202 and the stopping of transport.

[0047] The sensor control unit 403 includes an IN3 transmission sensor control unit 403a as a first sensor control unit and an IN3 reflection sensor control unit 403b as a second sensor control unit.

[0048] The IN3 transmissive sensor control unit 403a controls the IN3 transmissive sensor 230 to measure and record the label spacing (or label length), which is the spacing between each label 304 on the continuous paper P. When the IN3 transmissive sensor control unit 403a detects that the roll paper 202 has run out of paper, it has the function of determining, based on the recorded data, the printed page at which fluctuations in the label spacing, etc. (in other words, changes in the conveying speed) have exceeded the acceptable range for print quality.

[0049] The IN3 reflection sensor control unit 403b controls the IN3 reflection sensor 231 to measure the black mark interval, which is the interval between the black marks 305 on the back surface of the continuous paper P.

[0050] (A-2) Operation of the embodiment Next, the operation of the printer 1 according to the first embodiment having the above configuration will be described. First, the operation of measuring the label interval and determining the fluctuation will be described, and then the flow of the printing operation of the printer 1 incorporating this operation will be described.

[0051] (A-2-1) Measurement of label intervals and determination of fluctuations In the first embodiment, the IN3 transmissive sensor control unit 403a detects the label edge using the IN3 transmissive sensor 230 each time a label 304 of the continuous paper P passes, and measures and records the label interval. In addition, the paper management unit 402 records the ID of the print page that has completely passed the fixing EXIT sensor 233 when recording the label interval (which corresponds one-to-one to each label 304) as the print-completed page ID.

[0052] When the paper end sensor 208 detects that the paper is out, the IN3 transmissive sensor control unit 403a looks back at the recorded label spacing from the most recent recorded data to determine whether the label spacing has fluctuated. As a criterion for determining whether the label spacing has fluctuated, the average label spacing is calculated from a predetermined number of recent recorded data items (10 in the first embodiment, but the number is not particularly limited), and when the deviation from the average label spacing exceeds a predetermined fluctuation range (±0.5% in the first embodiment, but the fluctuation range is not particularly limited), it is determined that the roll paper 202 has reached the end and a change in transport speed that affects print quality has occurred.

[0053] At this time, the pages following the printed page are considered to have print quality problems, and are the pages that the user should check for print quality. The last printed page that passes the fixing EXIT sensor 233 before the paper end sensor 208 detects that the paper is out is considered to be the final printed page. Based on the difference between the final printed page ID and the printed page ID recorded when the label interval fluctuated, the system shows the user which page from the final printed page is the page to be checked, prompting the user to check the print quality. The system then prompts the user to select whether to add the page to be checked to recovery printing.

[0054] Figure 4(A) shows the feeder unit 10. As shown in Figure 4(A), when the tension bar 204 is at its lowest point, the maximum length of the path between the paper end sensor 208 and the roll paper folder 203 is defined as the maximum path length 501 (x [mm]). This maximum path length 501 (x [mm]) is considered to be equivalent to the length of the roll paper 202 (continuous paper P) that is transported after the roll paper 202 reaches its end and before the paper end sensor 208 detects that the paper has run out.

[0055] In the first embodiment, the IN3 transmissive sensor control unit 403a determines fluctuations in the label spacing by tracing back the printed pages from the last printed page to the maximum path length 501 (x [mm]). Therefore, the number of data points required to record the measured label spacing is equal to the number of data points going back the maximum path length 501 (x [mm]), and this value is calculated by dividing the maximum path length 501 (x [mm]) by the label length + gap length of the set print medium. However, because 10 pieces of recorded data are used to calculate the average label spacing, if the calculated number of pieces of recorded data is less than 10, up to 10 pieces of recorded data are recorded. However, the number of pieces of data to trace back the recorded data is limited to the calculated number of pieces of recorded data.

[0056] Also, as shown in FIG. 5(b), after the passage of the final print page by the fixing EXIT sensor 233 is detected, the final print page is transported a paper discharge distance 502 (y [mm]) to the discharge destination.

[0057] (A-2-2) Printer 1 printing operation 5 to 8 are flowcharts showing the characteristic operations of the printer according to the first embodiment.

[0058] <s100> When the user inputs the label length (the length of the labels 304 in the conveying direction) and the gap length (the length of the gap between each label 304) via the panel of the printer 1, the panel control unit 401 receives the input information. The panel control unit 401 notifies the printer control unit 400 of the input information.

[0059] Subsequently, when a print job is submitted to printer 1 from a higher-level host (not shown), print job receiving unit 404 receives information about the print job. Print job receiving unit 404 notifies printer control unit 400 of the print job information. Printer control unit 400 notifies paper position management unit 402a and paper transport control unit 402b of print page information and paper feed instructions.

[0060] When the paper transport control unit 402b receives the paper feed instruction, it starts feeding the roll paper 202.

[0061] <s101> The paper position management unit 402a determines whether the print medium has been changed based on the notified label length and gap length.

[0062] If the paper position management unit 402a determines that the print medium has not been changed, the process proceeds to step S104, which will be described later. On the other hand, if the print medium has been changed, the paper position management unit 402a instructs the IN3 transmission sensor control unit 403a via the printer control unit 400 to initialize the label interval recording data, and the process proceeds to the next step, S102.

[0063] <s102> The IN3 transmissive sensor control unit 403a initializes the label interval recording data.

[0064] <s103> The paper position management unit 402a notifies the IN3 transmissive sensor control unit 403a of the notified label length and gap length via the printer control unit 400. The IN3 transmissive sensor control unit 403a calculates the number of label interval recording data from the maximum path length 501 (x [mm]), label length, and gap length.

[0065] <s104> The sensor control unit 403 continues to monitor whether the paper end sensor 208 detects that the paper is out.

[0066] If the paper end sensor 208 detects that the paper is out of paper, the sensor control unit 403 issues a conveyance stop instruction to the paper conveyance control unit 402b via the printer control unit 400, and then proceeds to step S132, which will be described later. On the other hand, if the paper end sensor 208 does not detect that the paper is out of paper, the sensor control unit 403 proceeds to the next step S105.

[0067] <s105> The IN3 transmission sensor control unit 403a continues to monitor whether the IN3 transmission sensor 230 detects the leading edge of the label. If the IN3 transmission sensor 230 cannot detect the leading edge of the label, the process proceeds to the next step S104. On the other hand, if the IN3 transmission sensor 230 can detect the leading edge of the label, the process proceeds to step S106, which will be described later.

[0068] <s106> The sensor control unit 403 continues to monitor whether the paper end sensor 208 detects that the paper is out.

[0069] If the paper end sensor 208 detects that the paper is out of paper, the sensor control unit 403 issues a conveyance stop instruction to the paper conveyance control unit 402b via the printer control unit 400, and then proceeds to step S132, which will be described later. On the other hand, if the paper end sensor 208 does not detect that the paper is out of paper, the sensor control unit 403 proceeds to the next step S107.

[0070] <s107> The IN3 transmission sensor control unit 403a continues to monitor whether the IN3 transmission sensor 230 detects the leading edge of the gap. If the IN3 transmission sensor 230 cannot detect the leading edge of the gap, the process proceeds to step S109, which will be described later. On the other hand, if the IN3 transmission sensor 230 can detect the leading edge of the label, the process proceeds to the next step, S108.

[0071] <s108> The IN3 transmissive sensor control unit 403a starts measuring the label interval.

[0072] <s109> The IN3 transmissive sensor control unit 403a continues to monitor whether the IN3 transmissive sensor 230 detects the trailing end of the gap. If the IN3 transmissive sensor 230 cannot detect the trailing end of the gap, the process proceeds to step S112, which will be described later. On the other hand, if the IN3 transmissive sensor 230 can detect the trailing end of the label, the process proceeds to the next step, S110.

[0073] <s110> The IN3 transmissive sensor control unit 403a ends the measurement of the label interval.

[0074] <s111> The IN3 transmission sensor control unit 403a records the measured label interval.

[0075] <s112> The sensor control unit 403 continues to monitor whether the fixing exit sensor 233 detects the continuous paper P. If the paper end sensor 208 does not detect that the paper is out, the sensor control unit 403 transitions to step S106 described above. On the other hand, if the fixing exit sensor 233 detects the continuous paper P, the sensor control unit 403 instructs the paper position management unit 402a via the printer control unit 400 to initialize the transport amount from the fixing exit sensor 233, and transitions to step S113.

[0076] <s113> The paper position management unit 402 a initializes the transport amount from the fixing exit sensor 233 .

[0077] <s114> The sensor control unit 403 continues to monitor whether the paper end sensor 208 detects that the paper is out.

[0078] If the paper end sensor 208 detects that the paper is out of paper, the sensor control unit 403 issues a conveyance stop instruction to the paper conveyance control unit 402b via the printer control unit 400, and then proceeds to step S132, which will be described later. On the other hand, if the paper end sensor 208 does not detect that the paper is out of paper, the sensor control unit 403 proceeds to the next step, S115.

[0079] <s115> The IN3 transmission sensor control unit 403a continues to monitor whether the IN3 transmission sensor 230 detects the leading edge of the gap. If the IN3 transmission sensor 230 cannot detect the leading edge of the gap, the process proceeds to step S117, which will be described later. On the other hand, if the IN3 transmission sensor 230 can detect the leading edge of the label, the process proceeds to the next step, S116.

[0080] <s116> The IN3 transmissive sensor control unit 403a starts measuring the label interval.

[0081] <s117> The IN3 transmissive sensor control unit 403a continues to monitor whether the IN3 transmissive sensor 230 detects the trailing end of the gap. If the IN3 transmissive sensor 230 cannot detect the trailing end of the gap, the process proceeds to step S120, which will be described later. On the other hand, if the IN3 transmissive sensor 230 can detect the trailing end of the label, the process proceeds to the next step, S118.

[0082] <s118> The IN3 transmissive sensor control unit 403a ends the measurement of the label interval.

[0083] <s119> The IN3 transmission sensor control unit 403a records the measured label interval.

[0084] <s120> The paper position management unit 402a calculates and updates the transport amount from the fixing EXIT sensor 233 based on the linear speed of the discharge roller 226 and the elapsed time.

[0085] <s121> The paper position management unit 402a determines whether printing of all received print pages has been completed based on whether or not a notification that printing of all pages has been completed has been received in step S126, which will be described later. If printing of all pages has been completed, the paper position management unit 402a proceeds to step S127, which will be described later. On the other hand, if printing of all pages has not been completed, the paper position management unit 402a proceeds to the next step, S122.

[0086] <s122> The paper position management unit 402a determines whether the transport amount from the fixing EXIT sensor 233 exceeds the label length + gap length. If the paper position management unit 402a determines that the transport amount does not exceed the "label length + gap length," it transitions to step S114 described above. On the other hand, if the paper position management unit 402a determines that the transport amount exceeds the "label length + gap length," it transitions to the next step, S123.

[0087] <s123> The paper position management unit 402 a initializes the transport amount from the fixing exit sensor 233 .

[0088] <s124> The paper position management unit 402a counts up the print-completed page ID and proceeds to step S125.

[0089] <s125> The paper position management unit 402a determines whether the print-completed page ID matches the last page ID of the print page information. If the paper position management unit 402a determines that the print-completed page ID does not match the last page ID, it transitions to step S114 described above. On the other hand, if the paper position management unit 402a determines that the print-completed page ID matches the last page ID, it transitions to the next step S126.

[0090] <s126> The paper position management unit 402a notifies the paper transport control unit 402b and the printer control unit 400 that printing of all pages has been completed.

[0091] <s127> If it is determined in step S121 above that all printing pages have been completed, the paper position management unit 402a determines whether the transport amount from the fixing EXIT sensor 233 has exceeded the paper discharge distance 502 (y [mm]).

[0092] If the paper position management unit 402a determines that the paper discharge distance 502 (y [mm]) has not been exceeded, the process proceeds to step S114. On the other hand, if the paper position management unit 402a determines that the paper discharge distance 502 (y [mm]) has been exceeded, the process proceeds to step S128, where the paper position management unit 402a instructs the paper transport control unit 402b to stop transport.

[0093] <s128> The paper transport control unit 402b performs control to stop the transport of the continuous paper P.

[0094] Next, the details of the label interval recording process in steps S111 and S119 (FIG. 7) will be described.

[0095] <s129> The IN3 transmissive sensor control unit 403a records the measured label interval and requests the paper position management unit 402a via the printer control unit 400 to notify the print-completed page ID.

[0096] At this time, data is recorded for the number of label interval record data calculated in step S103 above, so if the number of recorded data has been reached, the oldest recorded data is deleted and updated. Also, if the number of label interval record data calculated in step S103 above is less than 10, at least 10 will be recorded so that the average label interval can be calculated.

[0097] <s130> The paper position management unit 402a notifies the IN3 transmissive sensor control unit 403a of the printed page ID, which is then recorded by the IN3 transmissive sensor control unit 403a together with the label interval recorded in step S129.

[0098] At this time, data is recorded for the number of label interval record data calculated in step S103 above, so if the number of recorded data has been reached, the oldest recorded data is deleted and updated. Also, if the number of label interval record data calculated in step S103 above is less than 10, at least 10 will be recorded so that the average label interval can be calculated.

[0099] <s131> The IN3 transmission sensor control unit 403a counts up the number of recorded data.

[0100] Next, recovery printing (FIG. 8) after detecting that the printer is out of paper will be described.

[0101] <s132> The paper transport control unit 402b stops transporting the continuous paper P and instructs the panel control unit 401 via the printer control unit 400 to display a message indicating that the paper is out.

[0102] <s133> The panel control unit 401 displays a message indicating that the paper is out on the panel.

[0103] <s134> The IN3 transmissive sensor control unit 403a determines whether the number of recorded data items is less than 10. If the number of recorded data items is less than 10, the IN3 transmissive sensor control unit 403a determines that it is not possible to determine the variation in label spacing with high accuracy, requests the printer control unit 400 to determine whether all printing pages have been completed, and proceeds to step S142, described below. On the other hand, if the number of recorded data items is 10 or more, the IN3 transmissive sensor control unit 403a determines that it is possible to determine the variation in label spacing with high accuracy, and proceeds to the next step, S135.

[0104] <s135> The IN3 transmissive sensor control unit 403a calculates the average label interval from the most recent 10 pieces of recorded data.

[0105] <s136> The IN3 transmissive sensor control unit 403a determines whether there is any label spacing that varies by ±0.5% or more from the average label spacing, starting with the most recent recorded data. If there is no fluctuating recorded data, the IN3 transmissive sensor control unit 403a requests the printer control unit 400 to determine whether all print pages have been completed, and proceeds to step S142, which will be described later. On the other hand, if there is fluctuating recorded data, the IN3 transmissive sensor control unit 403a issues a notification request for the printed page ID to the paper position management unit 402a via the printer control unit 400, and proceeds to the next step, S137.

[0106] <s137> The IN3 transmissive sensor control unit 403a calculates the difference between the notified final print completion page ID and the print completion page ID recorded together with the changed label interval, and notifies the calculated difference to the panel control unit 401 via the printer control unit 400.

[0107] <s138> The panel control unit 401 displays on the panel to prompt the user to check the print quality of the difference number of pages from the last printed page.

[0108] <s139> The panel control unit 401 displays a message to the user to select whether or not the page for which the print quality is to be checked should be subject to recovery printing.

[0109] <s140> When the panel control unit 401 receives a selection from the user as to whether the page for which print quality is to be checked is to be subjected to recovery printing, the panel control unit 401 notifies the printer control unit 400 of the selection result.

[0110] <s141> The printer control unit 400 determines whether the page for which print quality is to be checked needs to be added to the list of pages to be subject to recovery printing. If it is not necessary, the printer control unit 400 proceeds to step S142. On the other hand, if it is necessary, the printer control unit 400 requests the IN3 transmissive sensor control unit 403a to notify it of the printed page ID recorded together with the changed label interval, and proceeds to step S143, which will be described later.

[0111] <s142> The printer control unit 400 determines whether printing of all print pages has been completed by checking whether the notification of completion of printing of all pages has been received in step S126 described above. If printing has not been completed, the printer control unit 400 issues a notification request of the last printed page to the paper position management unit 402a and proceeds to step S144 described below. On the other hand, if printing has been completed, the printer control unit 400 ends the series of processes.

[0112] <s143> If the printer control unit 400 selects in step S141 above that recovery printing of the target page is required, the printer control unit 400 targets the pages following the page after the printed page ID recorded in conjunction with the notified changed label interval for recovery printing.

[0113] <s144> Furthermore, if it is not determined in step S142 above that all pages have been printed, printer control unit 400 subjects pages following the notified last printed page ID to recovery printing.

[0114] The process of recovery printing itself for the pages set in steps S143 and S144 described above is the same as the existing process, and therefore a description thereof will be omitted.

[0115] (A-3) Effects of the First Embodiment The first embodiment provides the following advantages.

[0116] The printer 1 records the label spacing measured by the IN3 transmissive sensor 230, and also records the printed page ID at the time of recording. Furthermore, when the paper end sensor 208 detects that the paper is out, the printer 1 compares the recorded label spacing with the average label spacing calculated from the most recent 10 recorded label spacings, and if there is a deviation of ±0.5% or more from the average label spacing, it determines that the transport speed has changed due to the roll paper reaching its end. This makes it possible to detect with high accuracy any change in transport speed that occurs when the roll paper reaches its end, and to obtain the printed page ID at the time of the occurrence.

[0117] Then, by comparing the last printed page ID when the paper end sensor 208 detects that the paper is out with the printed page ID obtained when the change in conveying speed occurs, the printer 1 obtains the printed page that completed printing after the change in conveying speed occurred, and can show the user on a panel which page from the last printed page this corresponds to, and prompt the user to check the print quality.

[0118] Furthermore, the user can select whether to include the page to be checked for print quality in the pages to be subjected to recovery printing, and it is up to the user to decide whether to add the page to the pages to be subjected to recovery printing.

[0119] This allows the user to be notified of the pages to be printed after the end of the roll paper has been reached that were not included in the pages to be subjected to recovery printing, and the pages to be printed after the end of the roll paper has been reached can be recovery printed according to the user's discretion.

[0120] (B) Second embodiment A second embodiment of an image forming apparatus according to the present disclosure will be described below in detail with reference to the drawings. In the following, an example in which the image forming apparatus according to the present disclosure is applied to a printer will be described.

[0121] (B-1) Configuration of the second embodiment The components of the printer 1A of the second embodiment are basically the same as those described in the first embodiment, so Figures 1 to 4 of the first embodiment can also be used in the second embodiment. Furthermore, differences in the operation of each component from the first embodiment will be described in the section on operation.

[0122] (B-2) Operation of the Second Embodiment Next, the operation of the printer 1A according to the second embodiment having the above configuration will be described. First, the operation of measuring the label interval and determining the fluctuation will be described, and then the flow of the printing operation of the printer 1A incorporating this operation will be described.

[0123] (B-2-1) Measurement of label intervals and determination of fluctuations In the second embodiment, the IN3 transmissive sensor control unit 403a detects the label edge and measures and records the label interval each time each label 304 of the continuous paper P passes. At this time, if the number of data items already recorded is 10 or more, the IN3 transmissive sensor control unit 403a determines whether the label interval to be recorded has changed.

[0124] As in the first embodiment, the IN3 transmissive sensor control unit 403a calculates the average label spacing from the most recent 10 print data items as a criterion for determining fluctuations in label spacing. If the average label spacing fluctuates by ±0.5% or more, it sets a transport speed occurrence flag and records the print-completed page ID at the time of printing.

[0125] If the paper end sensor 208 does not detect that the paper is out by the time the paper has been transported the maximum path length 501 (x [mm]) in Figure 4(A) described above, this transport speed generation flag is cleared, assuming that the detection of the end of the roll paper was an error.

[0126] In the second embodiment, if the paper end sensor 208 detects that the paper is out while the transport speed occurrence flag is set, it is determined that the roll paper has reached its end and a change in transport speed that affects print quality has occurred. Pages following the printed page recorded when the transport speed occurrence flag was set are pages with print quality problems and are the pages for which the user must check print quality. The last printed page that passes the fixing EXIT sensor 233 before the paper end sensor 208 detects that the paper is out is determined to be the final printed page. Based on the difference between this final printed page ID and the label spacing recorded when the transport speed occurrence flag was set, the system indicates to the user which page from the final printed page the page to be checked is, prompting the user to check the print quality. The user is then prompted to select whether to add the page to be checked to recovery printing.

[0127] Also, as in the first embodiment, after the passage of the final printed page by the fixing EXIT sensor 233 is detected as shown in FIG. 4(B), the paper is transported a paper discharge distance 502 (y [mm]) so that the final printed page is transported to the discharge destination.

[0128] (B-2-2) Printing operation of printer 1A Figures 9 to 12 are flowcharts showing the characteristic operations of the printer according to the second embodiment. In Figures 9 to 12, the processes associated with the same reference numerals as those in Figures 5 to 8 are the same as those in the first embodiment, and therefore their explanations will be omitted. The following describes the processes unique to the second embodiment.

[0129] <s201> After it is determined in step S104 above that the paper end sensor 208 has not detected that the paper is out, the IN3 transmissive sensor control unit 403a continues to monitor whether the IN3 transmissive sensor 230 detects the leading edge of the label. If the IN3 transmissive sensor 230 cannot detect the leading edge of the label, the process proceeds to step S104 above. On the other hand, if the IN3 transmissive sensor 230 can detect the leading edge of the label, the process instructs the paper position management unit 402a via the printer control unit 400 to initialize the transport amount from the IN3 transmissive sensor 230, and then proceeds to step S202, which will be described later.

[0130] <s202> The paper position management unit 402 a initializes the transport amount from the IN3 transmission sensor 230 .

[0131] <S203、S204> The IN3 transmission sensor control unit 403a determines the change in the transport speed.

[0132] Next, the details of the process of determining whether or not there is a change in the conveying speed in steps S203 and S204 (FIG. 11) will be described.

[0133] <s205> The IN3 transmissive sensor control unit 403a records the measured label interval. At this time, the IN3 transmissive sensor control unit 403a records 10 pieces of data, so when the number of recorded data reaches 10, the oldest recorded data is deleted and updated.

[0134] <s206> The IN3 transmissive sensor control unit 403a determines whether the number of recorded data items is less than 10. If the number of recorded data items is less than 10, the IN3 transmissive sensor control unit 403a transitions to step S215, which will be described later. On the other hand, if the number of recorded data items is 10 or more, the IN3 transmissive sensor control unit 403a transitions to the next step S207.

[0135] <s207> The IN3 transmissive sensor control unit 403a determines whether the conveying speed change occurrence flag is set. If the conveying speed change occurrence flag is set, the IN3 transmissive sensor control unit 403a proceeds to step S212, which will be described later. On the other hand, if the conveying speed change occurrence flag is not set, the IN3 transmissive sensor control unit 403a proceeds to the next step S208.

[0136] <s208> The IN3 transmissive sensor control unit 403a determines whether the measured label spacing varies by ±0.5% or more from the average label spacing. If the measured label spacing varies, the IN3 transmissive sensor control unit 403a proceeds to the next step S209. On the other hand, if the measured label spacing does not vary, the IN3 transmissive sensor control unit 403a proceeds to step S210, which will be described later.

[0137] <s209> The IN3 transmissive sensor control unit 403a sets a transport speed change flag and instructs the paper position management unit 402a via the printer control unit 400 to record the print-completed page ID.

[0138] <s210> The paper position management unit 402a records the print-completed page ID when a change in the transport speed occurs.

[0139] <s211> The IN3 transmissive sensor control unit 403a calculates and updates the average label interval from the most recently recorded 10 label intervals.

[0140] <s212> On the other hand, if it is determined in step S207 that the transport flag is set, the paper position management unit 402a calculates and updates the transport amount from the IN3 transmissive sensor 230 based on the linear speed of the transport roller 225-3 and the elapsed time.

[0141] <s213> The paper position management unit 402a determines whether the transport amount from the IN3 transmissive sensor 230 exceeds x [mm]. If the transport amount from the IN3 transmissive sensor 230 exceeds x [mm], the paper position management unit 402a transitions to the next step S214. On the other hand, if the transport amount from the IN3 transmissive sensor 230 does not exceed x [mm], the paper position management unit 402a transitions to the above-mentioned step S211.

[0142] <s214> The IN3 transmission sensor control unit 403a clears the conveying speed change flag, and the process proceeds to step S211 described above.

[0143] <s215> Furthermore, if it is determined in step S206 that the number of recorded data is less than 10, the IN3 transmission sensor control unit 403a counts up the number of recorded data, and the process proceeds to step S211.

[0144] Next, recovery printing (FIG. 12) after detecting that the printer is out of paper will be described.

[0145] <s216> After step S132, the panel control unit 401 displays a message indicating that the paper is out on the panel, and then instructs the IN3 transmissive sensor control unit 403a via the printer control unit 400 to determine whether a conveyance speed change has occurred.

[0146] <s217> The IN3 transmissive sensor control unit 403a determines whether the conveying speed change occurrence flag is set. If the conveying speed change occurrence flag is set, the IN3 transmissive sensor control unit 403a instructs the paper position management unit 402a via the printer control unit 400 to calculate the difference between the last printed page ID and the printed page ID when the conveying speed change occurred, and proceeds to the next step S217. On the other hand, if the conveying speed change occurrence flag is not set, the IN3 transmissive sensor control unit 403a proceeds to the above-mentioned step S142.

[0147] <s218> The paper position management unit 402a calculates the difference between the last printed page ID and the printed page ID when the conveyance speed change occurs.

[0148] <s219> Paper position management unit 402a determines whether the difference between the last printed page ID and the printed page ID when the conveying speed change occurred is zero (0). If the difference is zero, paper position management unit 402a transitions to step S142 described above. On the other hand, if the difference is not zero, paper position management unit 402a notifies panel control unit 401 of the calculated difference via printer control unit 400, and transitions to step S138 described above.

[0149] The subsequent processing is basically the same as in the first embodiment, and therefore a description thereof will be omitted.

[0150] (B-3) Effects of the Second Embodiment According to the second embodiment, the following effects are achieved.

[0151] Printer 1A records the label spacing measured by IN3 transmissive sensor 230, and if 10 or more data points have already been recorded, it compares it with the average label spacing calculated from the most recent 10 label spacings. If the spacing varies by ±0.5% or more from the average label spacing, it sets a conveyance speed change flag as a change in the conveyance speed and records the print completion page ID.

[0152] Furthermore, when the paper end sensor 208 detects that the printer 1A is out of paper, it determines whether the transport speed change flag is set. If the transport speed change flag is set, it determines that the transport speed has changed because the roll paper has reached its end. This allows the change in transport speed that occurs when the roll paper reaches its end to be detected with high accuracy, and the printed page ID at the time of the change can be obtained.

[0153] Then, by comparing the last printed page ID when the paper end sensor 208 detects that the paper is out with the obtained printed page ID when the change in conveyance speed occurs, the printed pages that completed printing after the change in conveyance speed occurred can be obtained, and the user can be shown on a panel which page from the last printed page corresponds to, and be prompted to check the print quality. Furthermore, the user can select whether to include pages for which print quality check is to be made in the pages to be subject to recovery printing, and it is up to the user to decide whether to add them to the pages to be subject to recovery printing.

[0154] This allows the user to be notified of the pages to be printed after the end of the roll paper has been reached that were not included in the pages to be subjected to recovery printing, and the pages to be printed after the end of the roll paper has been reached can be recovery printed according to the user's discretion.

[0155] (C) Other embodiments Although various modified embodiments have been mentioned in the first and second embodiments described above, the present disclosure can also be applied to the following modified embodiments.

[0156] (C-1) In the first and second embodiments, the label spacing is measured and fluctuations in the label spacing are monitored, but the target may be the label length. Also, if the medium has black marks, the IN3 reflective sensor 231 may measure the black mark spacing and perform processing similar to that described above.

[0157] (C-2) In the first and second embodiments, the label spacing fluctuation is determined based on whether it has varied by more than ±0.5% from the average label spacing. However, if the end of the roll paper is not taped to the core, it may be determined based on whether it has varied by more than -0.5%. [Explanation of symbols]

[0158] 1, 1A... printer, 10... feeder unit, 20... printing unit, 30... image forming unit, 202... roll paper, 203... roll paper folder, 204... tension bar, 205-1... feeder transport roller, 208... paper end sensor, 211... transport motor, 212... belt motor, 214... fuser motor, 214a... backup roller, 215... toner drum unit, 216... LED head, 217... primary transfer roller, 222... intermediate transfer belt, 223... secondary transfer roller, 225... transport roller, 226... discharge roller, 227... IN1 sensor, 228... IN2 sensor, 229... IN3 lever sensor, 230... IN3 transmission sensor, 231... IN3 reflective sensor, 2 32...pre-fixing slack sensor, 233...fixing EXIT sensor, 234...EXIT sensor, 235...fixing unit, 236...heating belt, 237...fixing backup roller, 250...paper exit, 301...light-emitting element, 302...light-receiving element, 303...backing paper, 304...label, 305...black mark, 311...light-emitting element, 312...light-receiving element, 313...reflector, 400...printer control unit, 401...panel control unit, 402...paper management unit, 402a...paper position management unit, 402b...paper transport control unit, 403...sensor control unit, 403a...IN3 transmissive sensor control unit, 403b...IN3 reflective sensor control unit, 404...print job receiving unit, 501...maximum path length, 502...paper discharge distance, P...continuous paper, R1, R2...transport path.

Claims

1. a rolled medium holding means for holding a rolled medium on which a plurality of labels are provided at predetermined intervals; a continuous paper detection means for detecting whether or not continuous paper has been pulled out from the rolled medium held by the rolled medium holding means; a first sensor for detecting a label interval, which is a predetermined interval between each label on the continuous paper; a first sensor control means for recording data on each label interval detected by the first sensor together with identification information of the print page that passed through a fixing unit at the timing when each label interval was detected, and for determining a fluctuation in each label interval for a predetermined amount of transport after the end of the rolled medium is reached and the continuous paper detection means no longer detects the continuous paper; an image forming control means for performing recovery printing on the next page and subsequent pages of the print page recorded in correspondence with the label interval that has fluctuated in the first sensor control means; An image forming apparatus comprising:

2. 2. The image forming apparatus according to claim 1, wherein the image forming control means allows the user to select whether or not to include the next page of the print page recorded in accordance with the label interval that has fluctuated in the first sensor control means in recovery printing.

3. the first sensor detects a label length instead of the label interval; The first sensor control means recording the data of each label length detected by the first sensor together with identification information of the print page that passed through a fixing unit at the timing when each label length was detected; Determining the variation in the length of each label instead of the label interval 3. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

4. The back surface of the rolled medium is provided with a black mark, a second sensor for detecting a predetermined interval between black marks on the continuous paper; a second sensor control means for recording data on the intervals between the black marks detected by the second sensor together with identification information of the print page that passed through the fixing unit at the timing when the intervals between the black marks were detected, and for determining a fluctuation in the intervals between the labels conveyed by a predetermined distance after the end of the rolled medium is reached and the continuous paper detection means no longer detects the continuous paper; and The image forming control means sets the next page of the print page recorded in correspondence with the black mark interval that has changed in the second sensor control means as the target of recovery printing.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

Images