Printing device and estimation method

Abstract

To provide a method for accurately estimating a residual amount of roll paper.SOLUTION: A label printer 1 comprises an estimation unit 105 for estimating the residual amount of roll paper using the following equation (1): R=PF / (π*REV), where REV is the cumulative rotation amount of the roll paper measured by a first measurement unit 103, PF is the cumulative conveyance amount of the conveyed roll paper measured by a second measurement unit 104, R is the diameter of the roll paper, and π represents a circular constant. The first measurement unit 103 resets the measured cumulative rotation amount every time the estimation unit 105 estimates the residual amount of the roll paper or every time it estimates the residual amount of the roll paper a plurality of times. The second measurement unit 104 resets the measured cumulative conveyance amount every time the estimation unit 105 estimates the residual amount of the roll paper or every time it estimates the residual amount of the roll paper a plurality of times. The estimation unit 105 filters the diameter of the roll paper calculated using the equation (1), and estimates a residual amount of the roll paper by regarding the filter-processed diameter as the residual amount of the roll paper.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a printing device and an estimation method. [Background technology]

[0002] Conventionally, techniques for estimating the remaining amount of roll paper are known. Patent Document 1 discloses a technology for estimating the remaining amount of roll paper, which uses a reflection sensor that generates a detection signal every time the rolled recording medium rotates a predetermined amount, and calculates the remaining amount of the rolled recording medium from the number of drive pulses to the motor that drives the recording paper feed roller within the detection signal generation period of this reflection sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-172683 Summary of the Invention [Problem to be solved by the invention]

[0004] The calculation in Patent Document 1 takes advantage of the proportional relationship between the amount of rotation of the roll recording medium and the amount of transport of the roll paper recording medium. However, in a printing device that prints on roll paper like the one in Patent Document 1, the amount of rotation of the roll paper and the amount of transport of the print medium unwound from the roll paper are not necessarily proportional. For example, in order to maintain a certain amount of transport of the print medium, the smaller the diameter of the roll paper, the greater the amount of rotation of the roll paper must be. As mentioned above, Patent Document 1 takes advantage of the proportional relationship between the amount of rotation of the roll recording medium and the amount of transport of the roll paper recording medium in its calculation, which may result in inaccurate calculation of the remaining amount of the roll recording medium. [Means for solving the problem]

[0005] One aspect of the invention that solves the above-described problem includes a feeding mechanism that rotates roll paper to feed a printing medium from the roll paper, a transport mechanism that transports the printing medium fed by the feeding mechanism, a printing unit that prints on the printing medium transported by the transport mechanism, a first measurement unit that measures an accumulated rotation amount that is a cumulative value of the rotation amount of the roll paper, and a second measurement unit that measures an accumulated transport amount that is a cumulative value of the transport amount of the printing medium transported by the transport mechanism, and using the following equation (1) where REV is the accumulated rotation amount measured by the first measurement unit, PF is the accumulated transport amount measured by the second measurement unit, and R is the diameter of the roll paper: and an estimation unit that estimates the remaining amount of the roll paper, wherein the first measurement unit resets the measured cumulative rotation amount each time the estimation unit estimates the remaining amount of the roll paper or each time the remaining amount of the roll paper is estimated multiple times, the second measurement unit resets the measured cumulative conveyance amount each time the estimation unit estimates the remaining amount of the roll paper or each time the remaining amount of the roll paper is estimated multiple times, and the estimation unit calculates the diameter of the roll paper using formula (1), filters the calculated diameter of the roll paper, and estimates the filtered diameter of the roll paper as the remaining amount of the roll paper. R=PF / (π REV) Equation (1) Here, π represents the ratio of the circumference of a circle to its circumference.

[0006] Another aspect of the present invention for solving the above-described problem is an estimation method for a printing device that includes a feeding mechanism that rotates roll paper to feed a printing medium from the roll paper, a transport mechanism that transports the printing medium fed by the feeding mechanism, and a printing unit that prints on the printing medium transported by the transport mechanism, the method comprising the steps of measuring an accumulated rotation amount, which is a cumulative value of the rotation amount of the roll paper, measuring an accumulated transport amount, which is a cumulative value of the transport amount of the printing medium transported by the transport mechanism, and calculating the following where REV is the measured accumulated rotation amount, PF is the measured accumulated transport amount, and R is the diameter of the roll paper: The method includes the steps of: estimating the remaining amount of roll paper using formula (1); resetting the measured cumulative rotation amount each time the remaining amount of roll paper is estimated or each time the remaining amount of roll paper is estimated multiple times; and resetting the measured cumulative conveyance amount each time the remaining amount of roll paper is estimated or each time the remaining amount of roll paper is estimated multiple times, wherein the estimating step calculates the diameter of the roll paper using formula (1), filters the calculated diameter of the roll paper, and estimates the filtered diameter of the roll paper as the remaining amount of the roll paper. R=PF / (π REV) Equation (1) Here, π represents the ratio of the circumference of a circle to its circumference. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 illustrates the configuration of a label printer. [Figure 2] A view of the feed control lever from above. [Figure 3] View of the feed control plate from the right. [Figure 4] FIG. 2 is a block diagram showing the configuration of a control system of the label printer. [Figure 5] 4 is a flowchart showing the operation of the label printer. [Figure 6] 10 is a diagram showing the relationship between the diameter of the roll paper and the cumulative conveyance amount. [Figure 7] 10 is a diagram illustrating the driving of the feeding mechanism and the transport mechanism. [Figure 8]10 is a diagram showing the relationship between the diameter of the roll paper and the cumulative conveyance amount. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment will be described with reference to the drawings. 1, 2, and 3 illustrate the X-axis, Y-axis, and Z-axis. The X-axis, Y-axis, and Z-axis are perpendicular to each other. The Z-axis indicates the up-down direction. The X-axis and Y-axis are parallel to the horizontal direction. The X-axis indicates the left-right direction. The Y-axis indicates the front-back direction. The positive direction of the X-axis indicates the right direction. The positive direction of the Y-axis indicates the forward direction. The positive direction of the Z-axis indicates the upward direction.

[0009] FIG. 1 is a diagram showing the configuration of a label printer 1. The label printer 1 is an example of a "printing device."

[0010] The label printer 1 is a serial inkjet printer that stores roll paper RS, transports the stored roll paper RS ​​in a transport direction H, and prints on the roll paper RS ​​using a print head 2, which is a serial inkjet head.

[0011] The roll paper RS ​​is a roll of label paper with labels attached at regular intervals to a backing sheet. The label printer 1 uses a print head 2 to print on the labels on the roll paper RS.

[0012] The label printer 1 is equipped with a roll paper compartment 3 that accommodates roll paper RS. In the following explanation, the roll-shaped portion of the roll paper RS ​​that is accommodated in the roll paper compartment 3 is referred to as the "roll body" and is designated with the symbol "RB." Additionally, the label paper of the roll paper RS ​​that is unwound from the roll body RB and transported is referred to as the "transported roll paper" and is designated with the symbol "RH." The transported roll paper RH is an example of a "print medium."

[0013] The roll paper accommodation unit 3 is equipped with a support member 4. The support member 4 supports the roll body RB via a cylindrical core member located in the center of the roll body RB. The support member 4 is connected to the motor shaft of the payout drive motor 5 via a power transmission mechanism, and rotates in response to the drive of the payout drive motor 5. This causes the roll body RB to rotate in conjunction with the rotation of the support member 4, and the transported roll paper RH is paid out from the roll body RB. A transport path along which the transported roll paper RH is transported is formed within the label printer 1. The transported roll paper RH paid out from the roll body RB is transported along the transport path in the transport direction H.

[0014] The label printer 1 is equipped with a feed control lever 6. The feed control lever 6 is located downstream of the roll paper compartment 3 in the transport direction H. The feed control lever 6 moves in response to changes in the length of the transported roll paper RH between the roll paper compartment 3 and the transport roller pair 7. More specifically, the feed control lever 6 rotates about a rotation axis KJ that extends left and right in response to changes in the length of the transported roll paper RH between the roll paper compartment 3 and the transport roller pair 7. In the following description, clockwise and counterclockwise directions are rotational directions based on the state when the payout control lever 6 is viewed from the right.

[0015] The label printer 1 is equipped with a transport roller pair 7. The transport roller pair 7 is located downstream of the feed control lever 6 in the transport direction H. The transport roller pair 7 has a transport rotation roller 71 and a transport driven roller 72 that rotates in response to the rotation of the transport rotation roller 71. The transport driven roller 72 is located opposite the transport rotation roller 71 in the transport path of the transported roll paper RH. The transport rotation roller 71 is connected to the transport drive motor 8 via a power transmission mechanism (not shown), and rotates in response to the drive of the transport drive motor 8. The transport roller pair 7 holds the transported roll paper RH between the transport rotation roller 71 and the transport driven roller 72, and transports the transported roll paper RH, which is unwound from the roll paper compartment 3, in the transport direction H as the transport rotation roller 71 rotates.

[0016] The label printer 1 includes a printing unit 9. The printing unit 9 is provided downstream of the transport roller pair 7 in the transport direction H. The printing unit 9 includes a carriage 10 and a print head 2 mounted on the carriage 10. The printing unit 9 is an example of a "printing section."

[0017] The carriage 10 is supported by a carriage shaft 11 that extends in a direction perpendicular to the transport direction H, and causes the print head 2 to scan along the carriage shaft 11 in the perpendicular direction. The print head 2 has nozzle rows for four colors, CMYK, for example. The print head 2 receives a supply of ink from an ink storage unit (not shown), such as an ink cartridge or ink tank, and ejects the ink from the nozzles provided in each nozzle row to form dots on the conveyed roll paper RH. Note that the print head 2 is not limited to a head capable of color printing using the four colors CMYK, but may also be a head capable of full-color printing using multiple ink colors, for example, by adding special color inks to the four colors CMYK, or a head capable of monochrome printing or two-color printing.

[0018] A platen 12 is provided in the transport path of the transported roll paper RH, at a position opposite the print head 2. The platen 12 extends over the range in which dots can be formed by the print head 2, and flattens and supports the transported roll paper RH so that the surface of the transported roll paper RH located on the platen 12 is perpendicular to the ejection direction of ink from the print head 2. The platen 12 may also be a so-called suction platen, which applies a suction force to the transported roll paper RH to adsorb it.

[0019] The label printer 1 includes a control device 13 that controls each part of the label printer 1. Details of the control device 13 will be described later.

[0020] The payout control lever 6 will now be described in detail. FIG. 2 is a view of the payout control lever 6 seen from above.

[0021] The feed control lever 6 includes a feed control plate 61 and a tension member 62 . The tension member 62 rotates around the rotation axis KJ in response to changes in the length of the paper roll RH being transported between the paper roll compartment 3 and the transport roller pair 7. The tension member 62 is biased by a biasing member 63, such as a spring, and applies a predetermined tension to the paper roll RH being transported between the paper roll compartment 3 and the transport roller pair 7. After the paper roll RH is unwound upward from the roll body RB in the transport path for the paper roll RH, it is hung over the tension member 62 and bent forward.

[0022] FIG. 3 is a view of the feed control plate 61 as seen from the right. The feed control plate 61 is a fan-shaped member. The feed control plate 61 of this embodiment is made of a material with light-blocking properties. A notch 611 is formed in the outer peripheral edge of the feed control plate 61. The notch 611 is formed to extend in the circumferential direction from the rear end edge RTA, which corresponds to the radius of the fan shape. The circumferential length of the notch 611 corresponds to the angle θ1. The angle θ1 is the angle from the rear end edge RTA with the rotation center O of the rotation axis KJ as the vertex.

[0023] The feed control plate 61 is disposed so that the center of the sector in the vertical direction coincides with the rotation center O of the rotation axis KJ. The feed control plate 61 rotates around the rotation axis KJ in synchronization with the rotation of the tension member 62.

[0024] The label printer 1 is equipped with a detector 14. The detector 14 is an optical sensor that includes an irradiation unit 141 that emits light and a light receiving unit 142 that receives light. The irradiation unit 141 is composed of, for example, an LED (Light Emitting Diode) or a laser light emitting element. The light receiving unit 142 is composed of, for example, a phototransistor or a photo IC. The feed control plate 61 is provided between the irradiation unit 141 and the light receiving unit 142 in the left-right direction. The irradiation unit 141 emits light toward the feed control plate 61. In this embodiment, the irradiation unit 141 emits light to the right. The light receiving unit 142 is provided in a position facing the irradiation unit 141, with its light receiving surface facing the feed control plate 61.

[0025] When the location to which the irradiating unit 141 irradiates light is other than the notch 611, the light irradiated by the irradiating unit 141 is blocked by the feed control plate 61. In this case, the light irradiated by the irradiating unit 141 is not received by the light receiving unit 142, and the detector 14 outputs a low-level detection value. On the other hand, when the portion onto which the irradiating unit 141 irradiates light is the notch 611, the notch 611 transmits the light irradiated by the irradiating unit 141. Therefore, the light irradiated by the irradiating unit 141 is received by the light receiving unit 142, and the detector 14 outputs a high-level detection value.

[0026] When the feed control lever 6 is in its home position, the illumination unit 141 illuminates position I1 with light. The home position of the feed control lever 6 is the position of the feed control lever 6 when it has rotated the furthest counterclockwise within its rotatable range, and is determined by the biasing force of the biasing member 63. The feed control lever 6 does not rotate counterclockwise from its home position. When the feed control lever 6 rotates clockwise from its home position by an angle θ2 or more, the illumination unit 141 illuminates the notch 611 with light.

[0027] FIG. 4 is a block diagram showing the configuration of the control system of the label printer 1. The label printer 1 includes an input device 15, a display device 16, and a communication device 17. The input device 15, display device 16, and communication device 17 are connected to the control device 13. The input device 15 is a device through which the user of the label printer 1 inputs printing conditions and the like, and is an input device such as a keyboard or mouse. The input device 15 may be a desktop or laptop personal computer, a tablet terminal, a portable terminal, or the like, and may be provided separately from the label printer 1. The input device 15 outputs information input by the operator to the control device 13. The display device 16 has a display screen such as an LCD panel, and displays various information under the control of the control device 13. The communication device 17 has communication hardware such as a communication circuit that complies with a specified communication standard, and communicates with devices separate from the label printer 1 according to the specified communication standard.

[0028] The control device 13 includes a processor 100 such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), a memory 110, an interface 120, and a drive circuit .

[0029] The processor 100 controls each part of the control device 13 by reading and executing a control program 111 stored in the memory 110. The processor 100 includes, as functional parts, a device control part 101, a print control part 102, a first measurement part 103, a second measurement part 104, and an estimation part 105. By executing the control program 111 stored in the memory 110, the processor 100 functions as the device control part 101, the print control part 102, the first measurement part 103, the second measurement part 104, and the estimation part 105. The device control unit 101 corresponds to an example of a "notification unit."

[0030] The memory 110 stores a control program 111 executed by the processor 100, setting data related to the settings of the label printer 1, and various other data. The memory 110 has a non-volatile storage area. The memory 110 may also have a volatile storage area and constitute a work area for the processor 100.

[0031] The interface 120 includes communication hardware such as a connector, an interface circuit, etc. The interface 120 is connected to the input device 15, the display device 16, and the communication device 17, and performs data communication with each of these devices.

[0032] The label printer 1 includes a feeding mechanism 18, a transport mechanism 19, a carriage moving unit 20, a print head 2, and a detector 14.

[0033] The payout mechanism 18 includes a payout drive motor 5 and a support member 4. The payout drive motor 5 is connected to and controlled by the control device 13. The control device 13 drives the payout drive motor 5 to rotate the support member 4.

[0034] The transport mechanism 19 includes a transport drive motor 8 and a transport roller pair 7. The transport drive motor 8 is connected to and controlled by the control device 13. The control device 13 drives the transport drive motor 8 to rotate the transport rotary roller 71, causing the transport roller pair 7 to transport the transport roll paper RH.

[0035] The carriage moving unit 20 includes components such as the carriage 10, a motor for scanning the carriage 10, and a power transmission mechanism for transmitting the power of the motor to the carriage 10. The control device 13 drives the motor included in the carriage moving unit 20 to move the carriage 10 in the left-right direction.

[0036] The print head 2 is connected to a control device 13. The control device 13 drives the print head 2 to eject ink toward the transported roll paper RH. The control device 13 controls the carriage movement unit 20 and the print head 2 to move the carriage 10 while ejecting ink from the print head 2, and also to transport the transported roll paper RH in the transport direction H.

[0037] A detector 14 is connected to the control device 13. The control device 13 acquires a detection value of the detector 14 and reflects it in the control of the payout mechanism 18.

[0038] As described above, the processor 100 functions as the device control unit 101, the print control unit 102, the first measurement unit 103, the second measurement unit 104, and the estimation unit 105.

[0039] The device control unit 101 accepts operator operations via the input device 15, displays various information on the display device 16, and communicates with devices separate from the label printer 1 via the communication device 17. The device control unit 101 notifies the user of the label printer 1 of the remaining amount of roll paper RS ​​estimated by the estimation unit 105, which will be described later. The device control unit 101 may notify the user of the label printer 1 of the remaining amount of roll paper RS ​​estimated by the estimation unit 105 by displaying information indicating the remaining amount of roll paper RS ​​on the display device 16. The device control unit 101 may also notify the user of the label printer 1 of the remaining amount of roll paper RS ​​estimated by the estimation unit 105 by sending information indicating the remaining amount of roll paper RS ​​via the communication device 17 to a terminal device used by the user of the label printer 1. The device control unit 101 notifies the user of the remaining amount of roll paper RS ​​when a trigger for notification occurs. Examples of such triggers include the estimation unit 105 estimating the remaining amount of roll paper RS, printing being completed, the arrival of a predetermined time for notification, or the user inputting an instruction to the input device 15 to be notified of the remaining amount of roll paper RS.

[0040] The print control unit 102 controls the feeding mechanism 18, the transport mechanism 19, the carriage movement unit 20, and the print head 2 to perform printing on the transported roll paper RH. The print control unit 102 drives the transport drive motor 8 in accordance with the transport drive data. The transport drive data is data related to the drive of the transport drive motor 8, and describes the drive time for driving the transport drive motor 8, the stop time for stopping the transport drive motor 8, and so on. The transport drive data is stored in memory 110. The print control unit 102 of this embodiment drives the transport drive motor 8 in a control mode that repeatedly drives and stops the motor at a predetermined cycle in accordance with the transport drive data. The print control unit 102 controls the driving of the payout mechanism 18 based on the detection value of the detector 14. When the detector 14 outputs a low-level detection value, the print control unit 102 stops driving the payout drive motor 5 and stops the payout of the transported roll paper RH from the roll body RB. When the detector 14 outputs a high-level detection value, the print control unit 102 drives the payout drive motor 5 and pays out the transported roll paper RH from the roll body RB. The print control unit 102 outputs information on the rotation speed and driving time of the feed drive motor 5 to the first measurement unit 103. The print control unit 102 also outputs information on the rotation speed and driving time of the transport drive motor 8 to the second measurement unit 104.

[0041] The first measurement unit 103 measures the cumulative rotation amount, which is the cumulative value of the rotation amount of the roll paper RS. The first measurement unit 103 measures the cumulative rotation amount based on the rotation amount of the feed drive motor 5. The first measurement unit 103 acquires information on the rotation speed and drive time of the feed drive motor 5 from the print control unit 102. The first measurement unit 103 then calculates the rotation amount of the roll paper RS ​​from this acquired information and measures the cumulative rotation amount by cumulatively counting the calculated rotation amount of the roll paper RS. The first measurement unit 103 outputs the measured cumulative rotation amount to the estimation unit 105. When first reset information is output from the estimation unit 105, the first measurement unit 103 resets the measured cumulative rotation amount. In other words, the first measurement unit 103 resets the measured cumulative rotation amount to zero. After the reset, the first measurement unit 103 measures the cumulative rotation amount again, starting from zero. The cumulative rotation amount may be reset every time the cumulative rotation amount is measured, or every time the cumulative rotation amount is measured multiple times.

[0042] The second measurement unit 104 measures the accumulated transport amount, which is the cumulative value of the transport amount of the transported roll paper RH. The second measurement unit 104 measures the accumulated transport amount based on the amount of rotation of the transport drive motor 8. The second measurement unit 104 acquires information on the number of rotations and drive time of the transport drive motor 8 from the print control unit 102. The second measurement unit 104 then calculates the transport amount of the transported roll paper RH from this acquired information and measures the accumulated transport amount by cumulatively counting the calculated transport amount of the transported roll paper RH. When second reset information is output from the estimation unit 105, the second measurement unit 104 resets the measured accumulated transport amount. In other words, the second measurement unit 104 resets the measured accumulated transport amount to zero. After the reset, the second measurement unit 104 measures the accumulated transport amount again from the value of zero. The reset of the accumulated transport amount may be performed each time the accumulated transport amount is measured, or may be performed each time the accumulated transport amount is measured multiple times.

[0043] The estimation unit 105 estimates the remaining amount of roll paper RS. In estimating the remaining amount of roll paper RS, the estimation unit 105 calculates the diameter of the roll paper RS ​​using the following equation (1). R=PF / (π REV) Equation (1) In equation (1), R represents the diameter of the roll paper RS. In equation (1), PF represents the cumulative conveyance amount measured by the second measurement unit 104. In equation (1), π represents the ratio of the circumference of a circle to its circumference. In equation (1), REV represents the cumulative rotation amount measured by the first measurement unit 103.

[0044] When estimating the remaining amount of roll paper RS, the estimation unit 105 filters the diameter of roll paper RS ​​calculated using equation (1) and sets the filtered diameter of roll paper RS ​​as the remaining amount of roll paper RS. The estimation unit 105 performs filtering, such as moving average filtering or Kalman filtering, on the diameter of roll paper RS ​​calculated using equation (1). Moving average filtering is filtering using a moving average filter. Kalman filtering is filtering using a Kalman filter.

[0045] When performing moving average filter processing, the estimation unit 105 obtains the value to be processed in the moving average filter processing from memory 110 and calculates the moving average value using the obtained value to be processed and the diameter of the roll paper RS ​​calculated this time using equation (1). When the estimation unit 105 performs moving average filter processing, the memory 110 stores N values ​​to be processed in the moving average filter processing. Here, N is an integer greater than or equal to 1. The N values ​​stored in memory 110 are values ​​indicating the remaining amount of roll paper RS ​​previously estimated by the estimation unit 105 and are values ​​indicating the diameter of the roll paper RS ​​after filtering. The N values ​​stored in memory 110 are updated each time the estimation unit 105 estimates the remaining amount of roll paper RS. In other words, the N values ​​stored in memory 110 are updated to include the value of the remaining amount of roll paper RS ​​currently estimated by the estimation unit 105 and to exclude the value of the remaining amount of roll paper RS ​​estimated most recently.

[0046] When performing Kalman filter processing, the estimation unit 105 obtains from memory 110 a value indicating the previously estimated remaining amount of roll paper RS. The estimation unit 105 then performs Kalman filter processing using the value obtained from memory 110 and the diameter of roll paper RS ​​calculated this time using equation (1). When the estimation unit 105 performs Kalman filter processing, the memory 110 stores a value indicating the previously estimated remaining amount of roll paper RS. Each time the estimation unit 105 estimates the remaining amount of roll paper RS, this value is updated to the value indicating the currently estimated remaining amount of roll paper RS.

[0047] When the estimation unit 105 estimates the remaining amount of roll paper RS, it outputs first reset information to the first measurement unit 103. The first reset information is information that instructs the first measurement unit 103 to reset the cumulative rotation amount measured. Furthermore, once the estimation unit 105 has estimated the remaining amount of roll paper RS, it outputs second reset information to the second measurement unit 104. The second reset information is information that instructs the second measurement unit 104 to reset the cumulative conveyance amount measured.

[0048] Next, the operation of the label printer 1 will be described. FIG. 5 is a flowchart showing the operation of the label printer 1.

[0049] The print control unit 102 of the label printer 1 determines whether or not to start printing (step S1).

[0050] For example, in step S1, the print control unit 102 determines to start printing when print data is received from an external device. Also, for example, when the device control unit 101 receives a print start operation from a user via the input device 15, the print control unit 102 determines to start printing in step S1.

[0051] If the print control unit 102 determines not to start printing (step S1: NO), it performs the determination in step S1 again.

[0052] When the print control unit 102 determines that printing should be started (step S1: YES), the first measuring unit 103 starts measuring the cumulative rotation amount (step S2).

[0053] Next, the second measuring unit 104 starts measuring the cumulative conveyance amount (step S3). The processing order of steps S2 and S3 may be reversed, or steps S2 and S3 may be performed simultaneously.

[0054] Next, the estimation unit 105 determines whether or not it is time to estimate the remaining amount of roll paper RS ​​(step S4).

[0055] The remaining amount of roll paper RS ​​may be estimated, for example, when the cumulative rotation amount measured by the first measuring unit 103 reaches or exceeds a predetermined threshold. Furthermore, the timing for estimating the remaining amount of roll paper RS ​​may be, for example, when the cumulative transport amount measured by the second measuring unit 104 reaches or exceeds a predetermined threshold.

[0056] If the estimation unit 105 determines that it is not time to estimate the remaining amount of roll paper RS ​​(step S4: NO), the processor 100 performs the determination in step S8.

[0057] On the other hand, if the estimation unit 105 determines that it is time to estimate the remaining amount of roll paper RS ​​(step S4: YES), it estimates the remaining amount of roll paper RS ​​(step S5).

[0058] Next, the first measuring unit 103 resets the measured cumulative rotation amount (step S6).

[0059] Next, the second measuring unit 104 resets the measured cumulative transport amount (step S7). The processing order of steps S6 and S7 may be reversed, or steps S6 and S7 may be performed simultaneously.

[0060] Next, the print control unit 102 determines whether or not to end the printing (step S8).

[0061] For example, if there is unprocessed data among the data included in the print data, the print control unit 102 makes a negative determination in step S8.

[0062] If the print control unit 102 determines not to end printing (step S8: NO), it performs the processes from step S4 onwards again.

[0063] On the other hand, if the print control unit 102 determines that printing is to be ended (step S8: YES), it ends this process.

[0064] Next, the estimation accuracy of the estimation unit 105 will be described. Fig. 6 is a diagram showing the relationship between the diameter of the roll paper RS ​​and the cumulative transport amount, and Fig. 6 shows the simulation results. In the chart of FIG. 6, the vertical axis is set to the diameter of the roll paper RS, and the horizontal axis is set to the accumulated transport amount.

[0065] Graph GF1 in FIG. 6 shows the relationship between the true diameter of the roll paper RS ​​and the cumulative transport amount.

[0066] Graph GF2 in Figure 6 shows the relationship between the diameter of roll paper RS ​​and the cumulative conveyance amount determined using a conventional method. This conventional method calculates the diameter of roll paper RS ​​using equation (1) without resetting the cumulative rotation amount measured by the first measurement unit 103 and the cumulative conveyance amount measured by the second measurement unit 104. As is clear from comparing graphs GF1 and GF2, the diameter of roll paper RS ​​determined using the conventional method has a larger error from the true diameter of roll paper RS ​​as the cumulative conveyance amount increases.

[0067] This is for the following reasons. Equation (1) shows that PF is proportional to REV, with πR as the coefficient. However, the diameter of roll paper RS ​​decreases as the cumulative feed amount increases, and therefore the smaller the diameter of roll paper RS, the greater the amount of rotation of roll paper RS ​​per unit of feed amount of roll paper RS. In other words, conventional methods calculate the diameter of roll paper RS ​​by substituting the cumulative feed amount and cumulative rotation amount, which are not actually proportional, into equation (1), which assumes a proportional relationship, without taking into account changes in the diameter of roll paper RS. Therefore, with conventional methods, the greater the cumulative feed amount, the greater the error in the true diameter of roll paper RS.

[0068] In Fig. 6, the plots indicated by black circles indicate the diameter of the roll paper RS ​​calculated by the estimation unit 105 using equation (1) in a configuration in which the cumulative conveyance amount and cumulative rotation amount are reset each time the estimation unit 105 makes an estimation. The plots in Fig. 6 vary along the curve GF1 as the cumulative conveyance amount changes, even though they contain errors with respect to the curve GF1.

[0069] This is for the following reasons. By resetting the cumulative rotation amount and cumulative conveyance amount, the relationship between the cumulative rotation amount and cumulative conveyance amount at the time of reset can be reset to a relationship that corresponds to the diameter of the roll paper RS ​​at the time of reset. Therefore, by resetting the cumulative conveyance amount and cumulative rotation amount, the estimation unit 105 can take changes in the diameter of the roll paper RS ​​into account when calculating the diameter of the roll paper RS. As a result, the plot in FIG. 6 changes along graph GF1.

[0070] The plot in FIG. 6 has an error with respect to the graph GF1 because the payout mechanism 18 and the transport mechanism 19 are driven asynchronously.

[0071] FIG. 7 is a diagram for explaining the driving of the feeding mechanism 18 and the transport mechanism 19. In FIG. In FIG. 7, the first vertical axis is set to the cumulative transport amount. In FIG. 7, the second vertical axis is set to the cumulative payout amount. The cumulative payout amount is the cumulative value of the amount of transported roll paper RH paid out from the roll paper RS. The first vertical axis and the second vertical axis have the same scale. In FIG. 7, the horizontal axis is set to time. Graph GF3 in Fig. 7 shows the change over time of the cumulative conveyance amount, and graph GF4 in Fig. 7 shows the change over time of the cumulative feed amount.

[0072] When the label printer 1 starts printing at time T1, the transport mechanism 19 is driven, and the cumulative transport amount increases from time T1 onwards. Between times T1 and T2, the drive of the payout mechanism 18 is stopped. As a result, the length of the transported roll paper RH between the roll paper compartment 3 and the transport roller pair 7 becomes shorter between times T1 and T2. Therefore, between times T1 and T2, the payout control lever 6 rotates clockwise over time.

[0073] At time T2, when the rotation angle of the payout control lever 6 from the home position becomes equal to or greater than angle θ2, the detection value of detector 14 changes from low to high. When the detection value of detector 14 changes to high, the payout mechanism 18 is activated, and the cumulative payout amount increases from time T2 onwards. Note that if the payout amount per unit time by payout mechanism 18 is smaller than the transport amount per unit time by transport mechanism 19, the length of the transported roll paper RH between the roll paper compartment 3 and the transport roller pair 7 will be shorter. Also, if the payout amount per unit time by payout mechanism 18 is greater than the transport amount per unit time by transport mechanism 19, the length of the transported roll paper RH between the roll paper compartment 3 and the transport roller pair 7 will be longer. Therefore, the payout control lever 6 rotates clockwise when the payout amount per unit time by the payout mechanism 18 is smaller than the transport amount per unit time by the transport mechanism 19, and rotates counterclockwise when the payout amount per unit time by the payout mechanism 18 is greater than the transport amount per unit time by the transport mechanism 19.

[0074] When the driving of the transport mechanism 19 stops at timing T3, the cumulative transport amount stops increasing after timing T3.

[0075] Between times T3 and T4, when the rotation angle of the payout control lever 6 from the home position falls below angle θ2, the detection value of the detector 14 changes from high to low. When the detection value of the detector 14 changes to low, the drive of the payout mechanism 18 stops, and the cumulative payout amount stops increasing after time T4.

[0076] At timing T5, the transport mechanism 19 starts driving again, and the cumulative transport amount increases again from timing T5 onwards.

[0077] As described above, in the label printer 1, the transport mechanism 19 drives and stops at a predetermined cycle, and the feeding mechanism 18 drives and stops in response to changes in the level of the detection value of the detector 14. In this way, in the label printer 1, the transport mechanism 19 and the feeding mechanism 18 drive asynchronously.

[0078] 7, the time has come for the estimation unit 105 to estimate the remaining amount of roll paper RS. At time TA, the cumulative conveyed amount from reference KJ1 is smaller than the cumulative payout amount from reference KJ1. In this case, the diameter of roll paper RS ​​calculated using equation (1) at time TA is smaller than the true diameter of roll paper RS.

[0079] Assume that the timing for the estimation unit 105 to estimate the remaining amount of roll paper RS ​​arrives at timing TB in FIG. 7. At timing TB, the cumulative conveyance amount from reference KJ2 is greater than the cumulative payout amount from reference KJ3. In this case, the diameter of roll paper RS ​​calculated from equation (1) at timing TB is calculated as a value greater than the true diameter of roll paper RS. Note that the cumulative conveyance amount from reference KJ2 is the cumulative conveyance amount when the cumulative conveyance amount at timing TA is set to zero. Also, the cumulative payout amount from reference KJ3 is the cumulative payout amount when the cumulative payout amount at timing TA is set to zero.

[0080] Assume that the timing for the estimation unit 105 to estimate the remaining amount of roll paper RS ​​arrives at timing TC in Figure 7. At timing TC, the cumulative conveyance amount from reference KJ4 is greater than the cumulative payout amount from reference KJ4. In this case, the diameter of roll paper RS ​​calculated from equation (1) at timing TC is calculated as a value greater than the true diameter of roll paper RS. Note that the cumulative conveyance amount and cumulative payout amount from reference KJ4 are the cumulative conveyance amount and cumulative payout amount when the cumulative conveyance amount and cumulative payout amount at timing TB are set to zero.

[0081] Assume that the timing for the estimation unit 105 to estimate the remaining amount of roll paper RS ​​arrives at timing TD in FIG. 7. At timing TD, the cumulative conveyance amount from reference KJ6 is greater than the cumulative payout amount from reference KJ5. In this case, the diameter of roll paper RS ​​calculated from equation (1) at timing TD is calculated as a value greater than the true diameter of roll paper RS. Note that the cumulative conveyance amount from reference KJ6 is the cumulative conveyance amount when the cumulative conveyance amount at timing TC is set to zero. Also, the cumulative payout amount from reference KJ5 is the cumulative payout amount when the cumulative payout amount at timing TC is set to zero.

[0082] As described above, because the payout mechanism 18 and the conveyance mechanism 19 operate asynchronously, the cumulative payout amount may be greater than the cumulative conveyance amount or may be smaller than the cumulative conveyance amount, depending on the timing of the estimation by the estimator 105. The cumulative payout amount is determined by the diameter of the roll paper RS ​​and the cumulative rotation amount of the roll paper RS. Therefore, if the cumulative payout amount is greater or smaller than the cumulative conveyance amount, the relationship between the cumulative conveyance amount and the cumulative rotation amount substituted into equation (1) may not be constant. As a result, the diameter of the roll paper RS ​​calculated using equation (1) may have an error compared to the true diameter of the roll paper RS. As a result, the plot in Figure 6 will have an error compared to the true diameter of the roll paper RS. Therefore, to suppress the error compared to the true diameter of the roll paper RS, the estimator 105 performs filtering.

[0083] Fig. 8 is a diagram showing the relationship between the diameter of the roll paper RS ​​and the cumulative transport amount, and Fig. 8 shows the simulation results. In FIG. 8, the vertical axis is set to the diameter of the roll paper RS, and the horizontal axis is set to the accumulated transport amount.

[0084] The graph GF1 in Fig. 8 is the same as the graph GF1 in Fig. 6. The graph GF2 in Fig. 8 is the same as the graph GF2 in Fig. 6.

[0085] Graph GF5 in Fig. 8 is a graph obtained by performing moving average filtering on the plot in Fig. 6. As is clear from a comparison of graph GF5 in Fig. 8 with the plot in Fig. 6, graph GF5 in Fig. 8 has a smaller error with respect to graph GF1 than the plot in Fig. 6.

[0086] As described with reference to FIGS. 6 and 8, the reset by the first measuring unit 103 and the second measuring unit 104 and the filtering process by the estimating unit 105 enable the estimating unit 105 to estimate the remaining amount of roll paper RS ​​with high accuracy.

[0087] As described above, the label printer 1 is equipped with a feeding mechanism 18 that rotates the roll paper RS ​​to feed out the transported roll paper RH from the roll paper RS, a transport mechanism 19 that transports the transported roll paper RH fed by the feeding mechanism 18, a printing unit 9 that prints on the transported roll paper RH transported by the transport mechanism 19, a first measurement unit 103 that measures the cumulative rotation amount of the roll paper RS, a second measurement unit 104 that measures the cumulative transport amount of the transported roll paper RH transported by the transport mechanism 19, and an estimation unit 105 that estimates the remaining amount of roll paper RS ​​using equation (1) where REV is the cumulative rotation amount measured by the first measurement unit 103, PF is the cumulative transport amount measured by the second measurement unit 104, and R is the diameter of the roll paper RS. The first measurement unit 103 resets the measured cumulative rotation amount each time the estimation unit 105 estimates the remaining amount of roll paper RS, or each time it estimates the remaining amount of roll paper RS ​​multiple times. The second measurement unit 104 resets the measured cumulative conveyance amount each time the estimation unit 105 estimates the remaining amount of roll paper RS ​​or each time the estimation unit 105 estimates the remaining amount of roll paper RS ​​multiple times. The estimation unit 105 calculates the diameter of the roll paper RS ​​using equation (1) and estimates the remaining amount of roll paper RS ​​by filtering the calculated diameter of the roll paper RS.

[0088] This allows the remaining amount of roll paper RS ​​to be estimated taking the diameter of the roll paper RS ​​into account by resetting the cumulative rotation amount measured by the first measuring unit 103 and the cumulative conveyance amount measured by the second measuring unit 104. Furthermore, filtering the diameter of the roll paper RS ​​calculated using equation (1) reduces the error between the diameter of the roll paper RS ​​calculated using equation (1) and the true diameter of the roll paper RS. This allows the label printer 1 to accurately estimate the remaining amount of roll paper RS.

[0089] The filtering is a moving average filtering.

[0090] This allows the moving average filter to reduce the error between the diameter of the roll paper RS ​​calculated using equation (1) and the true diameter of the roll paper RS. Furthermore, using the moving average filter allows the diameter of the roll paper RS ​​to be determined with high accuracy at the timing when the estimation unit 105 makes the estimation. Therefore, the label printer 1 can accurately estimate the remaining amount of roll paper RS ​​at the timing when the estimation unit 105 makes the estimation.

[0091] The filtering is Kalman filtering.

[0092] This allows the filtering process of the Kalman filter to reduce the error between the diameter of the roll paper RS ​​calculated using equation (1) and the true diameter of the roll paper RS. Using the filtering process of the Kalman filter also allows the diameter of the roll paper RS ​​to be determined with high accuracy at the time the estimation unit 105 makes an estimation. Using the Kalman filter also means that the label printer 1 only needs to store the amount of remaining roll paper RS ​​that the estimation unit 105 previously estimated, eliminating the need to use a large amount of storage space in the memory 110. This means that the label printer 1 can accurately estimate the amount of remaining roll paper RS ​​at the time the estimation unit 105 makes an estimation, while minimizing increases in the usage rate of the memory 110.

[0093] The payout mechanism 18 and the transport mechanism 19 are driven asynchronously.

[0094] This makes it possible to reduce the difference between the diameter of the roll paper RS ​​calculated using formula (1) and the true diameter of the roll paper RS, even if this difference is due to the unsynchronized driving of the payout mechanism 18 and the transport mechanism 19. Therefore, even in a label printer 1 in which the payout mechanism 18 and the transport mechanism 19 are unsynchronized, it is possible to estimate the remaining amount of roll paper RS.

[0095] The label printer 1 includes a device control unit 101 that notifies the remaining amount of roll paper RS ​​estimated by the estimation unit 105.

[0096] This allows the user of the label printer 1 to know how much of the roll paper RS ​​is remaining.

[0097] The estimation method used by the label printer 1 includes the steps of measuring the cumulative rotation amount of the roll paper RS, measuring the cumulative feed amount of the transported roll paper RH, estimating the remaining amount of roll paper R using equation (1) where REV is the measured cumulative rotation amount, PF is the measured cumulative feed amount, and R is the diameter of the roll paper RS, resetting the measured cumulative rotation amount each time the remaining amount of roll paper RS ​​is estimated or after multiple estimates of the remaining amount of roll paper RS, and resetting the measured cumulative feed amount each time the remaining amount of roll paper RS ​​is estimated or after multiple estimates of the remaining amount of roll paper RS. In the estimation method, the estimating step calculates the diameter of the roll paper RS ​​using equation (1), and estimates the remaining amount of roll paper RS ​​by filtering the calculated diameter of the roll paper RS.

[0098] This provides the same advantages as the label printer 1 described above.

[0099] The above-described embodiment merely shows a specific example of application of the present invention. The present invention is not limited to the configuration of the above-described embodiment, and can be embodied in various forms without departing from the spirit of the invention.

[0100] For example, the above-described embodiment has illustrated a label printer 1 as an example of a printing device. However, the printing device is not limited to the label printer 1. The printing device may be any device that stores roll paper RS ​​and includes a feeding mechanism 18 that feeds out the roll paper RS, and a transport mechanism 19 that transports the transported roll paper RH that is fed from the roll paper RS. Specifically, the printing device may be a large format printer, a textile printing machine, or the like.

[0101] In the above embodiment, a serial head type print head 2 is exemplified, but a line head type print head may also be used. Furthermore, the printing method of the print head 2 is not limited to the inkjet type.

[0102] In the above-described embodiment, the payout mechanism 18 is configured to include the payout drive motor 5 and the support member 4. However, the payout mechanism 18 may also be configured to include one or more rollers located upstream of the payout control lever 6. The rollers included in the payout mechanism 18 may be rotating rollers, driven rollers, or both. The payout mechanism 18 may also be configured to include various power transmission mechanisms related to the payout of the transported roll paper RH.

[0103] In the above-described embodiment, the transport mechanism 19 is configured to include the transport drive motor 8 and the transport roller pair 7. However, the transport mechanism 19 may also be configured to include one or more rollers located downstream of the payout control lever 6. The rollers included in the transport mechanism 19 may be rotating rollers, driven rollers, or both. The transport mechanism 19 may also be configured to include various power transmission mechanisms related to the transport of the transported roll paper RH.

[0104] The feed control plate 61 may have a hole formed therein instead of the notch 611, or may be provided with a member that transmits the light emitted by the irradiation unit 141.

[0105] In the above-described embodiment, moving average filtering and Kalman filtering are exemplified as filtering processes performed by the estimation unit 105. However, the filtering processes performed by the estimation unit 105 are not limited to these two types of filtering processes. For example, the estimation unit 105 may be configured to perform filtering processes using a first-order lag filter or a second-order lag filter.

[0106] The processor 100 may be configured with a single processor or multiple processors. The processor 100 may be hardware programmed to implement corresponding functional units. That is, the processor 100 may be configured with, for example, an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0107] Furthermore, the components of the label printer 1 shown in Figure 4 are merely examples, and the specific implementation form is not particularly limited. In other words, it is not necessary to implement hardware that corresponds to each component individually; it is of course possible to configure the components so that the functions of each component are realized by a single processor executing a program. Furthermore, some of the functions realized by software in the above-described embodiment may be implemented by hardware, or some of the functions realized by hardware may be implemented by software. The specific detailed configurations of the other components of the label printer 1 can also be changed as desired.

[0108] Furthermore, for example, the operational step units shown in Figure 5 are divided according to the main processing content to make it easier to understand the operation of each part of the label printer 1, and the present invention is not limited by the way the processing units are divided or the names of the processing units. The processing may be divided into more step units depending on the processing content. Furthermore, one step unit may be divided so that it includes even more processing. Furthermore, the order of the steps may be changed as appropriate within the scope of the present invention. [Explanation of symbols]

[0109] 1...label printer (printing device), 2...print head, 3...roll paper storage section, 4...support member, 5...feed drive motor, 6...feed control lever, 7...pair of transport rollers, 8...transport drive motor, 9...printing unit (printing section), 13...control device, 14...detector, 15...input device, 16...display device, 17...communication device, 18...feed mechanism, 19...transport mechanism, 20...carriage movement section, 100...processor, 101...device control section (notification section), 102...printing control section, 103...first measurement section, 104...second measurement section, 105...estimation section, 110...memory, 111...control program, 120...interface, 130...drive circuit, 141...irradiation section, 142...light receiving section, RH...transported roll paper (printing medium), RS...roll paper.

Claims

1. a feeding mechanism that rotates the roll paper to feed the print medium from the roll paper; a conveying mechanism that conveys the print medium fed by the feeding mechanism; a printing unit that prints on the print medium transported by the transport mechanism; a tension member that applies tension to the print medium between the feeding mechanism and the transport mechanism; 、 a first measuring unit that measures an accumulated rotation amount, which is an accumulated value of the rotation amount of the roll paper; A cumulative transport amount, which is a cumulative value of the transport amount of the print medium transported by the transport mechanism, is calculated. a second measurement unit for measuring the The cumulative rotation amount measured by the first measurement unit is REV, and the cumulative rotation amount measured by the second measurement unit is REV. Using the following formula (1), where PF is the stack conveyance amount and R is the diameter of the roll paper, an estimation unit that estimates the remaining amount of roll paper; The first measuring unit is configured to measure the remaining amount of the roll paper each time the estimating unit estimates the remaining amount of the roll paper or after the estimation unit estimates the remaining amount of the roll paper. and resetting the measured cumulative rotation amount each time the unit estimates the remaining amount of the roll paper multiple times. 、 The second measuring unit is configured to measure the remaining amount of the roll paper each time the estimating unit estimates the remaining amount of the roll paper or after the estimation unit estimates the remaining amount of the roll paper. resetting the measured cumulative conveyance amount each time the unit estimates the remaining amount of the roll paper multiple times; 、 The estimation unit calculates the diameter of the roll paper using the formula (1) and The diameter of the roll paper is filtered, and the filtered diameter of the roll paper is used as the diameter of the roll paper. The remaining amount of paper is estimated as Printing device. R=PF / (π・REV)...Formula (1) Here, π represents the ratio of the circumference of a circle to its circumference.

2. A feeding mechanism that rotates the roll paper to feed the print medium from the roll paper; a conveying mechanism that conveys the print medium fed by the feeding mechanism; a printing unit that prints on the print medium transported by the transport mechanism; a first measuring unit that measures an accumulated rotation amount, which is an accumulated value of the rotation amount of the roll paper; A cumulative transport amount, which is a cumulative value of the transport amount of the print medium transported by the transport mechanism, is calculated. a second measurement unit for measuring the The cumulative rotation amount measured by the first measurement unit is REV, and the cumulative rotation amount measured by the second measurement unit is REV. Using the following formula (1), where PF is the stack conveyance amount and R is the diameter of the roll paper, an estimation unit that estimates the remaining amount of roll paper; the feeding mechanism and the transport mechanism are driven asynchronously, The first measuring unit is configured to measure the remaining amount of the roll paper each time the estimating unit estimates the remaining amount of the roll paper or after the estimation. and resetting the measured cumulative rotation amount each time the unit estimates the remaining amount of the roll paper multiple times. 、 The second measuring unit is configured to measure the remaining amount of the roll paper each time the estimating unit estimates the remaining amount of the roll paper or after the estimation unit estimates the remaining amount of the roll paper. resetting the measured cumulative conveyance amount each time the unit estimates the remaining amount of the roll paper multiple times; 、 The estimation unit calculates the diameter of the roll paper using the formula (1) and The diameter of the roll paper is filtered, and the filtered diameter of the roll paper is used as the diameter of the roll paper. The remaining amount of paper is estimated as Printing device. R=PF / (π・REV)...Formula (1) Here, π represents the ratio of the circumference of a circle to its circumference.

3. The feeding mechanism and the transport mechanism are driven asynchronously. The printing device of claim 1 .

4. The filtering is a moving average filtering. The printing device according to claim 1 .

5. a notification unit that notifies the user of the remaining amount of roll paper estimated by the estimation unit; The printing device according to any one of claims 1 to 4.

6. a feeding mechanism that rotates the roll paper to feed the print medium from the roll paper; a conveying mechanism for conveying the print medium fed by the conveying mechanism; a printing unit that prints on the print medium placed in the print position; and a printing unit that prints on the print medium placed in the print position between the feeding mechanism and the transport mechanism. and a tension member that applies tension to the medium, measuring an accumulated rotation amount, which is a cumulative value of the rotation amount of the roll paper; A cumulative transport amount, which is a cumulative value of the transport amount of the print medium transported by the transport mechanism, is calculated. measuring the The measured cumulative rotation amount is REV, the measured cumulative transport amount is PF, and the roll paper directivity is estimating the remaining amount of the roll paper using the following formula (1) where R is the diameter; 、 Each time the remaining amount of the roll paper is estimated or each time the remaining amount of the roll paper is estimated multiple times, a step of resetting the measured cumulative rotation amount; Each time the remaining amount of the roll paper is estimated or each time the remaining amount of the roll paper is estimated multiple times, and resetting the measured cumulative conveyance amount, The estimating step calculates the diameter of the roll paper using the formula (1), The diameter of the roll paper is filtered, and the filtered diameter of the roll paper is is estimated as the remaining amount of the roll paper. Estimation method. R=PF / (π・REV)...Formula (1) Here, π represents the ratio of the circumference of a circle to its circumference.

7. A feeding mechanism that rotates a roll of paper to feed a printing medium from the roll of paper; a conveying mechanism for conveying the print medium fed by the conveying mechanism; a printing unit that prints on the print medium, and the feeding mechanism and the transport mechanism are asynchronous. An estimation method for a printing device driven by measuring an accumulated rotation amount, which is a cumulative value of the rotation amount of the roll paper; A cumulative transport amount, which is a cumulative value of the transport amount of the print medium transported by the transport mechanism, is calculated. measuring the The measured cumulative rotation amount is REV, the measured cumulative transport amount is PF, and the roll paper directivity is estimating the remaining amount of the roll paper using the following formula (1) where R is the diameter; 、 Each time the remaining amount of the roll paper is estimated or each time the remaining amount of the roll paper is estimated multiple times, a step of resetting the measured cumulative rotation amount; Each time the remaining amount of the roll paper is estimated or each time the remaining amount of the roll paper is estimated multiple times, and resetting the measured cumulative conveyance amount, The estimating step calculates the diameter of the roll paper using the formula (1), The diameter of the roll paper is filtered, and the filtered diameter of the roll paper is is estimated as the remaining amount of the roll paper. Estimation method. R=PF / (π・REV)...Formula (1) Here, π represents the ratio of the circumference of a circle to its circumference.

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