JP6281519B2 - Paper type detection device and paper type detection method - Google Patents

Description

  The present invention relates to a paper type detection device and a paper type detection method.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a printer, or a multifunction peripheral, a technique for detecting the type of recording material (paper) stored by a user and adjusting the image forming conditions based on the detected type of recording material Exists. As a technique for detecting the type of the recording material, for example, Japanese Patent Application Laid-Open No. 2008-96617 (Patent Document 1) includes a recording material determination unit that measures the characteristics of the recording material and determines the type of the recording material, and a recording medium. An image forming apparatus including a printing condition determining unit that automatically determines a printing condition based on a determination result of a material determining unit is disclosed. This apparatus has an adjustment mode for adjusting a recording material determination threshold relating to the characteristics of the recording material for determining the recording material based on the type of the recording material designated by the user with respect to the determination result by the recording material determination means. Accordingly, it is possible to more appropriately determine the recording material designated by the user in the presence of an enormous variety of recording materials, and to automatically set the printing conditions for the designated recording material.

JP 2008-96617 A

  However, in the technique described in Patent Document 1, the recording material determination threshold value is adjusted only during the adjustment mode. Therefore, in normal printing, the determination result of the media sensor required for the determination of the recording material and the recording material determination The type of recording material is detected based on the threshold value. For this reason, when there is an error in the recording material discrimination threshold during normal printing, printing is performed corresponding to the wrong type of recording material, and the meaning of the adjustment mode is reduced.

  In particular, when an image forming apparatus that has been fed by a predetermined paper feed cassette performs printing immediately after being fed to the paper feed cassette, the paper that has been present in the paper feed cassette and the paper that has already been fed And a sheet of a different paper type (for example, thick paper) may be mixed in a sheet of a predetermined paper type (for example, plain paper). In such a case, in the image forming apparatus, although the paper type of the paper is properly detected, the recording material determination threshold is set to the wrong paper type by the user specifying the wrong paper type. Changed to paper type. Then, there exists a subject that the detection accuracy of the kind of recording material deteriorates.

  Therefore, the present invention has been made to solve the above-described problems, and an object thereof is to provide a paper type detection device and a paper type detection method that can improve the detection accuracy of the type of recording material. .

  A paper type detection device according to one aspect of the present invention includes a paper type detection unit, a paper type determination unit, an inquiry unit, a table correction unit, a next paper type detection unit, a next paper type determination unit, and a correction. A cancellation unit. When the paper is transported based on a predetermined setting condition, the paper type detection unit is based on a detection result of a media sensor provided in advance in the paper transport path and a paper type detection table provided in advance. The paper type of the conveyed paper is detected. The paper type determination unit determines whether or not the detected paper type of the detected paper matches the set paper type of the paper set in the setting condition. The inquiry unit displays a paper type selection screen that allows the user to select the paper type of the paper, and inquires the user about selection of a predetermined paper type. The table correction unit corrects the paper type detection table so that the detected paper type becomes the selected paper type. The next paper type detection unit detects the paper type of the next paper transported immediately after the paper type detection table is corrected based on the detection result of the media sensor and the paper type detection table before correction. . The next paper type determination unit determines whether or not the detected paper type of the detected next paper matches the selected paper type. If the detected paper type of the next paper does not match the selected paper type, the correction cancellation unit cancels the correction and leaves the paper type detection table as before correction. The table correction unit determines the correction of the paper type detection table when the detected paper type of the next paper matches the selected paper type.

  A paper type detection method according to one aspect of the present invention includes a paper type detection step, a paper type determination step, an inquiry step, a table correction step, a next paper type detection step, a next paper type determination step, and a correction. A cancellation step. In the paper type detection step, when the paper is transported based on a predetermined setting condition, based on a detection result of a media sensor provided in advance in the paper transport path and a paper type detection table provided in advance. The paper type of the conveyed paper is detected. The paper type determination step determines whether or not the detected paper type of the detected paper matches the set paper type of the paper set in the setting condition. The inquiry step displays a paper type selection screen that allows the user to select the paper type of the paper, and inquires the user about selection of a predetermined paper type. The table correction step corrects the paper type detection table so that the detected paper type becomes the selected paper type. In the next paper type detection step, based on the detection result of the media sensor and the paper type detection table before correction, the paper type of the next paper conveyed immediately after the correction of the paper type detection table is detected. . The next paper type determination step determines whether or not the detected paper type of the detected next paper matches the selected paper type. In the correction cancellation step, when the detected paper type of the next paper does not match the selected paper type, the correction is canceled and the paper type detection table remains as before correction.

  According to the paper type detection apparatus and the paper type detection method of the present invention, it is possible to improve the detection accuracy of the type of recording material.

1 is a schematic diagram of a multifunction machine according to an embodiment of the present invention. FIG. 3 is a schematic diagram of an operation unit of the multifunction peripheral according to the embodiment of the present invention. It is a figure which shows the structure of the control system hardware of the multifunctional device which concerns on embodiment of this invention. 1 is a functional block diagram of a multifunction peripheral according to an embodiment of the present invention. It is a flowchart for showing the execution procedure of the embodiment of the present invention. FIG. 6 is a diagram (FIG. 6A) showing an arrangement relationship between media sensors and registration rollers in a paper conveyance path, and a diagram (FIG. 6B) showing an example of correcting a paper type detection table. FIG. 7A shows an example of a paper type detection table when the detection paper type of the next paper matches the selected paper type, and paper type detection when the detection paper type of the next paper does not match the selection paper type. It is a figure (FIG. 7B) which shows an example of a table.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. In addition, the following embodiment is an example which actualized this invention, Comprising: The thing of the character which limits the technical scope of this invention is not. Moreover, the alphabet S added before the number in a flowchart means a step.

  An image forming apparatus will be described below as an example of an embodiment of the present invention. Note that the image forming apparatus of the present invention corresponds to, for example, a multi-function peripheral (MFP) having functions such as a copy, a scanner, and a printer.

  As illustrated in FIG. 1, the multifunction peripheral 100 receives print job setting conditions from the user via the operation unit 101, and receives an image reading unit 102, an image forming unit 103, a paper transport unit 104, a fixing unit 105, a paper type, and the like. Each unit such as the detection unit 106 is driven to provide the print job.

  The image reading unit 102 reads the image data of the original on the platen, the paper transport unit 104 transports the paper type corresponding to the setting condition from the paper feed cassette, and the image forming unit 103 converts the image data into the image data. The corresponding toner image is transferred to the paper. The fixing unit 105 fixes the toner image on a sheet, and discharges the sheet on which the toner image is fixed as a printed matter. The multi-function device 100 includes a paper type detection unit (media sensor) 106 in the paper conveyance path, and detects the paper type of the paper to be conveyed.

  As shown in FIG. 2, the operation unit 101 is provided with a touch panel 201 (operation panel) and operation keys 202, and a user inputs a predetermined instruction or performs a predetermined operation using the operation unit 101. Check the screen. On the touch panel 201, a predetermined screen is displayed, or information corresponding to the pressed key is input by pressing a key in the displayed screen. The operation keys 202 include, for example, a numeric keypad, a start key, a clear key, a stop key, a reset key, and a power key.

  As shown in FIG. 3, the control circuit of the multifunction peripheral 100 includes a CPU (Central Processing Unit) 301, a ROM (Read Only Memory) 302, a RAM (Random Access Memory) 303, an HDD (Hard Disk Drive) 304, and each drive unit. Are connected by an internal bus 306.

  The CPU of the multifunction device 100 uses, for example, a RAM as a work area, executes a program stored in a ROM, an HDD, and the like, and based on the execution result, data, instructions, and signals from the driver and the image reading unit 101 , And the like, and controls the operation of each drive unit shown in FIG. Further, for each unit (shown in FIG. 4) to be described later other than the drive unit, the CPU implements each unit by executing each program. A ROM, a RAM, an HDD, and the like store programs and data for realizing each unit described below.

  Next, the configuration and execution procedure according to the embodiment of the present invention will be described with reference to FIGS. 4 and 5. First, when the user turns on the power of the multifunction device 100, the display reception unit 401 of the multifunction device 100 displays an operation screen on the touch panel of the operation unit 101, and starts receiving a print job. When the user places an original on the platen, inputs a desired setting condition such as “plain paper”, for example, and selects a start key, the display receiving unit 401 corresponds to the setting condition. A print job is accepted and notification to that effect is sent to the print controller 402. Upon receiving the notification, the print control unit 402 starts executing the print job (FIG. 5: S101).

  For example, the print control unit 402 starts reading the image data of the original on the platen by the image reading unit 102, and starts forming a toner image by the image forming unit 103 based on the image data. Further, the print control unit 402 searches the paper feeding unit 104 for a paper feed cassette that stores paper of the paper type “plain paper” designated by the user based on the setting conditions of the print job, and performs the search. Paper is transported from the fed paper cassette.

  Here, when the print control unit 402 starts execution of the print job, it notifies the paper type detection unit 403 to that effect, and the paper type detection unit 403 that has received the notification is provided in advance in the paper conveyance path. Based on the detection result of the media sensor and a paper type detection table (recording material determination threshold table) provided in advance, the paper type of the conveyed paper is detected (FIG. 5: S102).

  Here, the method detected by the paper type detection unit 403 is not particularly limited. For example, as shown in FIG. 6A, a transport roller 601 for transporting paper is provided at a predetermined position downstream of the transport path 600 extending from the paper feed cassette, and the paper is skewed at a position downstream from the transport roller 601. A registration roller 602 for correcting the above is provided. A media sensor 603 is provided at a position between the transport roller 601 and the registration roller 602 at a position on the back side of the sheet.

  The configuration of the media sensor 603 is not particularly limited. The media sensor 603 includes, for example, a light source LED for light irradiation, a first imaging lens for imaging the light of the light source LED, and light imaged by the first imaging lens. A second imaging lens that reflects from the front surface (back surface) of the paper and forms an image of the reflected light, and a CMOS sensor that photographs the imaged reflected light are provided. Light from the light source LED is applied to the surface via the first imaging lens, and reflected light from the surface is condensed via the second imaging lens, and the CMOS sensor. Is imaged. Thereby, the measured value of the surface of the paper can be detected from the media sensor 603. The measured value of the media sensor 603 is not particularly limited as long as it is a value that can detect the paper type of the paper. For example, the reflectance (%) and transmittance (%) of the surface of the paper can be employed.

  A transfer roller 604 and a photosensitive drum 605 are provided at a position downstream of the registration roller 602, and a toner image is transferred onto a sheet. A fixing unit 105 including a heating roller and a pressure roller is provided at a position downstream of the transfer roller 604, and fixes the toner image on the sheet. A conveyance roller 606 is provided at a position downstream of the fixing unit 105, and the sheet on which the toner image is fixed is discharged as a printed matter.

  The paper type detection unit 403 monitors when the paper transport unit 104 is transporting paper. When the paper is stopped by the registration roller 602 to correct the skew of the paper, the paper type detection unit 403 activates the media sensor 603 to reflect the reflectance (%) and transmission of the surface of the paper. Get rate (%). Next, the paper type detection unit 403 refers to a paper type detection table stored in advance in a predetermined memory.

  Here, for example, as shown in FIG. 6B, the paper type detection table 607 has a reflectance (%) as a horizontal axis and a reciprocal of the transmittance (%) (a parameter indicating difficulty of transmission) as a vertical axis. A reciprocal of reflectance and transmittance indicating a predetermined paper type (for example, plain paper, thick paper, glossy paper (glossy paper)) is partitioned by a predetermined threshold 608. The paper type detection unit 403 plots the measurement points 609 of the reciprocal of the acquired reflectance and transmittance on the paper type detection table 607, and sets the measurement points 609 of the reciprocal of the plotted reflectance and transmittance. A specific paper type (for example, “thick paper”) indicated by the included area is detected as the paper type of the conveyed paper.

  When the paper type detection unit 403 completes the detection of the paper type, it notifies the paper type determination unit 404 to that effect, and the paper type determination unit 404 that has received the notification indicates that the detected paper type of the detected paper is the above described paper type. It is determined whether or not it matches the set paper type of the paper set in the print job setting conditions (FIG. 5: S103).

  As a result of the determination, when the detected paper type matches the set paper type (FIG. 5: S103 YES), the paper type of the paper set by the user matches the paper type of the paper that is actually conveyed. No problem in particular. Therefore, the paper type determination unit 404 does nothing particularly and completes the processing. In this case, as usual, the print control unit 402 transfers the toner image to the sheet being conveyed by the image forming unit 103, fixes the toner image to the sheet by the fixing unit 105, and executes printing (FIG. 5: S104). Then, the paper transport unit 104 discharges the printed material and completes the execution of the print job. In this case, for example, the media sensor 603 needs to be activated only once, the repeated activation of the media sensor 603 can be prevented, and the life of the media sensor 603 can be extended.

  On the other hand, if the result of the determination in S103 is that the detected paper type does not match the set paper type (FIG. 5: S103 NO), the paper type of the paper set by the user and the paper type of the paper that is actually being conveyed Is a problem because does not match. Therefore, the paper type determination unit 404 notifies the print control unit 402 to that effect, and the print control unit 402 that has received the notification stops the transport of the paper that is being transported (FIG. 5: S105). For example, the print control unit 402 is in a state where the conveyance of the sheet is stopped by the registration roller 602 via the sheet conveyance unit 104.

  Next, the paper type determination unit 404 notifies the inquiry unit 405 to that effect, and the inquiry unit 405 that receives the notification displays a paper type selection screen that allows the user to select the paper type of the paper. The user inquires about the selection of a predetermined paper type (FIG. 5: S106).

  Here, the method of inquiring by the inquiry unit 405 is not particularly limited. For example, as illustrated in FIG. 2, the inquiry unit 405 displays the paper type selection screen on the touch panel via the operation unit 101. The paper type selection screen 203 includes a message 204 that the detected paper type and the set paper type are different, a message 205 that prompts the user to select the paper type of the paper, and a paper type key 206 (for example, plain paper) that indicates the paper type. Key, cardboard key, glossy paper key, etc.) are displayed.

  For example, when the user selects a specific paper type key (for example, a plain paper key) indicating the desired paper type while viewing the paper type selection screen 203, the inquiry unit 405 causes the user to select a predetermined paper type. The selection of (“plain paper”) is accepted, and a notification to that effect is sent to the table correction unit 406. Upon receiving the notification, the table correction unit 406 corrects the paper type detection table 607 so that the detected paper type becomes the selected paper type (FIG. 5: S107).

  There is no particular limitation on the method of correction by the table correction unit 406. For example, as illustrated in FIG. 6B, the table correction unit 406 includes a first measurement point of the reciprocal of the reflectance and transmittance corresponding to the detected paper type (“thick paper”) in the paper type detection table 607. An area indicating each paper type in the paper type detection table 607 so that an area 610 in a certain range based on 609 (the detection result of the media sensor) becomes an area 611 indicating the selected paper type (“plain paper”). The threshold value 612 for partitioning is corrected.

  The method by which the table correction unit 406 corrects the threshold value 612 is not particularly limited. For example, as illustrated in FIG. 6B, at the first measurement point 609 when the selected paper type is “plain paper” and the detected paper type is “thick paper”, the table correction unit 406 performs the first correction. When the circle around the measurement point 609 is formed and the area 610 inside the circle overlaps the area 611 indicating the selected paper type, the table correction unit 406 changes the circle 612 to the selected paper type. It corrects as a new threshold value shown.

  Note that the size (radius) of the circle 612 may be automatically adjusted by the table correction unit 406, or after the table correction unit 406 has the user confirm it, stepwise according to the user's designation. You may comprise so that it may change. For example, the radius of the circle 612 may be expanded to a predetermined magnification (for example, 1.5 times, 2 times, etc.) designated by the user.

  When the table correction unit 406 completes the correction, the print control unit 402 is notified of this. Upon receiving the notification, the print control unit 402 resumes the execution of the print job as described above (FIG. 5: S108).

  Here, the table correction unit 406 further notifies the next paper type detection unit 407 to that effect, and the next paper type detection unit 407 that has received the notification notifies the detection result of the media sensor 603 and the paper type detection before correction. Based on the table 607, the paper type of the next paper transported immediately after the paper type detection table 607 is corrected is detected (FIG. 5: S109).

  Here, the method detected by the next paper type detection unit 407 is not particularly limited, and is the same as, for example, the paper type detection unit 403. In other words, the next paper type detection unit 407 acquires the reflectance (%) and transmittance (%) of the surface of the next paper stopped by the registration roller 602 using the media sensor 603. Next, the next paper type detection unit 407 refers to the paper type detection table 607 before correction. The paper type detection table 607 before correction is in a state before the above-described threshold value 612 is corrected as shown in FIG. 7A. The next paper type detection unit 407 plots the second measurement point 700 that is the reciprocal of the acquired reflectance and transmittance on the paper type detection table 607 before correction, and the plotted reflectance and transmittance. Is detected as the paper type of the next paper to be conveyed.

  When the next paper type detection unit 407 completes the detection of the paper type, the next paper type determination unit 408 is notified of this, and whether or not the detected paper type of the detected next paper matches the selected paper type. Is determined (FIG. 5: S110).

  As a result of the determination, if the detected paper type of the next paper does not match the selected paper type (FIG. 5: S110 NO), there is a high possibility that the user has mistakenly selected the paper type on the paper type selection screen. The correction is likely to be erroneous. This case corresponds to, for example, a case where a sheet of a different paper type is mixed in the sheet of the sheet feeding cassette. Since the detection of the paper type of the paper is based on the detection result of the media sensor 603 with the paper stopped on the registration roller 602 as described above, the user cannot take out the paper without permission, and the media sensor 603 The actual detected paper cannot be confirmed. Even if the user opens the paper feed cassette and confirms the paper, this paper corresponds to the next paper, so it is difficult to confirm a paper of a different paper type. Therefore, when the detected paper type of the next paper does not match the selected paper type, the next paper type determination unit 408 detects a paper of a different paper type by one and the user has selected the paper type by mistake. Is determined. Then, the next paper type determination unit 408 notifies the correction cancellation unit 409 to that effect, and the correction cancellation unit 409 that receives the notification cancels the correction and leaves the paper type detection table 607 unchanged. (FIG. 5: S111).

  In this case, for example, as shown in FIG. 7A, the set paper type is “plain paper”, the first detection paper type is “thick paper”, the selected paper type is “plain paper”, and two sheets When the detection paper type of the eye is “thick paper”, the “thick paper” paper is stored in the paper feed cassette, and the “normal paper” of the selected paper type is incorrect. Therefore, the correction cancellation unit 409 cancels the threshold value 612 and sets the paper type detection table 607 to a state before correction. This prevents the paper type detection table 607 from being erroneously corrected by detecting a paper of a different paper type. As a result, it is possible to improve the detection accuracy of the paper type.

  When the correction cancellation unit 409 completes cancellation, the print control unit 402 is notified of the cancellation, and the print control unit 402 that has received the notification executes printing as described above (FIG. 5: S104). In this case, for example, the print control unit 402 may execute printing after changing the setting conditions corresponding to the detected paper type of the next paper. In addition, the print control unit 402 may notify the user of a change in the setting conditions via the display reception unit 401.

  On the other hand, when the detected paper type of the next paper matches the selected paper type in S110 (FIG. 5: S110 YES), it is highly likely that the user has correctly selected the paper type on the paper type selection screen, and the correction is performed. Is likely to be appropriate. In this case, all the types of paper in the paper in the paper cassette are prepared, and, for example, as shown in FIG. 7B, the first measurement point 607 exists in the vicinity of the threshold value 608 before correction. is there. Therefore, when the detected paper type of the next paper matches the selected paper type, the next paper type determination unit 408 determines that the correction is appropriate. Then, the next paper type determination unit 408 notifies the table correction unit 406 to that effect, and the table correction unit 406 that has received the notification determines the correction of the paper type detection table 607 (FIG. 5: S112).

  In this case, for example, as shown in FIG. 7B, the set paper type is “plain paper”, the first detection paper type is “thick paper”, the selected paper type is “plain paper”, and two sheets When the detection paper type of the eye is “plain paper”, the “plain paper” is stored in the paper feed cassette, and the “thick paper” of the first detection paper type is erroneous for some reason. Therefore, the table correction unit 406 determines the threshold value 612 and executes correction of the paper type detection table 607. Thereby, the paper type detection table 607 is appropriately corrected, and the detection accuracy of the paper type can be improved.

  When the table correction unit 406 completes the correction, the print control unit 402 is notified of the correction, and the print control unit 402 that has received the notification executes printing as described above (FIG. 5: S104). In this case, printing is executed with the “plain paper” of the paper type as it is set.

  By the way, in the above-described embodiment, if the printing is normally executed in S104, the subsequent printing of the paper is configured to be terminated without further starting the media sensor 603. The configuration of For example, in S104, if it is determined in S103 that the detected paper type does not match the set paper type (FIG. 5: S103 NO), the process proceeds to S113, and the print control unit 402 does not complete the print job. If it determines (FIG. 5: S113NO), it will transfer to S102. Then, the print control unit 402 causes the paper type detection unit 403 to detect the paper type of the conveyed paper, and causes the paper type determination unit 404 to detect the detected paper type of the paper as the set paper type. It is determined whether or not it matches. That is, S102 to S104 are repeated for each sheet. As a result, even when the user mistakenly selects a paper type or when a single different paper type is frequently mixed in the paper feed cassette, the paper type of the paper can be detected appropriately.

  In the above description, the paper type is detected for each paper sheet, but other structures may be used. For example, in one print job, the media sensor is activated only for the first sheet, and the paper type of the sheet is detected. As a result, it is possible to take measures against the life of the media sensor and to detect the paper type only for the first sheet of one print job because there is a high possibility that the sheet is replaced at the turn of the print job. You may do it. In addition, if the quality of printed matter is important by detecting the paper type without considering the life of the media sensor, the paper type detection table 607 may be corrected by detecting the paper type for each sheet. . In this case, it is appropriate to cancel the correction of the paper type detection table 607 even if continuous printing is performed and, for some reason, only one sheet of different paper types is lost near the center of the paper in the paper cassette. Can be executed.

  In the embodiment of the present invention, the multifunction peripheral 100 includes the paper type detection device, but the paper type detection unit 403, the paper type determination unit 404, the inquiry unit 405, the table correction unit 406, and the next paper type detection unit. 407, a next paper type determination unit 408, and a correction cancellation unit 409 may be provided as a paper type detection device.

  In the embodiment of the present invention, the MFP 100 is configured to include each unit. However, a program that realizes each unit may be stored in a storage medium, and the storage medium may be provided. In this configuration, the program is read by the paper type detection device, and the paper type detection device realizes the units. In that case, the program itself read from the recording medium exhibits the effects of the present invention. Furthermore, it is also possible to provide a method for storing the steps executed by each unit in a hard disk.

  As described above, the paper type detection apparatus and the paper type detection method according to the present invention are useful not only for multifunction peripherals but also for image forming apparatuses such as copiers and printers and for single types of paper type detection apparatuses. This is effective as a paper type detection apparatus and paper type detection method capable of improving the detection accuracy.

DESCRIPTION OF SYMBOLS 100 MFP 401 Display reception part 402 Print control part 403 Paper type detection part 404 Paper type determination part 405 Inquiry part 406 Table correction part 407 Next paper type detection part 408 Next paper type determination part 409 Correction cancellation part

Claims (3)

When a sheet is transported based on a predetermined setting condition, based on a detection result of a media sensor provided in advance in the sheet transport path and a sheet type detection table provided in advance, the sheet to be transported A paper type detection unit for detecting the paper type;
A paper type determination unit that determines whether or not the detected paper type of the detected paper matches the set paper type of the paper set in the setting condition;
An inquiry section that displays a paper type selection screen that allows the user to select the paper type of the paper and inquires the user about selection of a predetermined paper type
A table correction unit that corrects the paper type detection table so that the detected paper type becomes the selected paper type;
Based on the detection result of the media sensor and the paper type detection table before correction, a next paper type detection unit that detects the paper type of the next paper conveyed immediately after the paper type detection table is corrected,
A next paper type determination unit that determines whether or not a detected paper type of the detected next paper matches the selected paper type;
If the detected paper type of the next paper does not match the selected paper type, a correction canceling unit that cancels the correction and leaves the paper type detection table before correction;
A paper type detection device comprising: The paper type detection apparatus according to claim 1, wherein the table correction unit determines correction of the paper type detection table when a detection paper type of the next paper matches the selected paper type. When a sheet is transported based on a predetermined setting condition, based on a detection result of a media sensor provided in advance in the sheet transport path and a sheet type detection table provided in advance, the sheet to be transported A paper type detection step for detecting the paper type;
A paper type determination step for determining whether or not the detected paper type of the detected paper matches the set paper type of the paper set in the setting condition;
An inquiry step for displaying a paper type selection screen that allows the user to select a paper type and inquiring the user to select a predetermined paper type;
A table correction step for correcting the paper type detection table so that the detected paper type becomes the selected paper type;
Based on the detection result of the media sensor and the paper type detection table before correction, a next paper type detection step of detecting the paper type of the next paper transported immediately after the paper type detection table is corrected,
A next paper type determination step for determining whether or not a detected paper type of the detected next paper matches the selected paper type;
A correction cancellation step of canceling the correction and leaving the paper type detection table uncorrected if the detected paper type of the next paper does not match the selected paper type;
A paper type detection method comprising:

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