JP2014177318A - Remaining amount derivation device for rolled recording medium, supply device for rolled recording medium, and remaining amount derivation method and program for rolled recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a remaining amount derivation device for a rolled recording medium that is suitable for deriving the remaining amount of a rolled recording medium in an easy method while preventing the recording medium from being damaged, a supply device for the rolled recording medium, and a remaining amount derivation method and a program for the rolled recording medium.SOLUTION: In a remaining amount derivation device for a rolled recording medium, acquisition means acquires, by a predetermined sensor, a position of a tension roller which applies tension to a recording medium, formed by rolling a recording medium for image formation, unwound from holding means of holding the rolled recording medium rotatably, and conveyed to image formation means of forming an image on the recording medium. Derivation means derives the remaining amount of the rolled recording medium held by the holding means based upon the position of the tension roller acquired by the acquisition means.

Description

  The present invention relates to a roll-shaped recording medium remaining amount deriving device, a roll-shaped recording medium supply device, a roll-shaped recording medium remaining amount deriving method, and a program.

  As a recording medium on which an image forming apparatus such as a printer, a copying machine, or a facsimile forms an image, there is a roll-shaped recording medium in which a recording medium such as paper or film is wound into a roll. Since a roll-shaped recording medium can be stored without being cut even if it is large, it is often used when a large area image is formed without breaks.

  In particular, when forming an image with a large area, it is necessary to properly derive the remaining amount of the recording medium on which image formation is possible in order to prevent erroneous processing such as a shortage of recording media during image formation. Become. As a method of deriving the remaining amount of the roll-shaped recording medium, a predetermined lead-out member is brought into contact with the outer periphery of the roll-shaped recording medium and the outer diameter or the peripheral speed is measured, and the roll shape is determined based on the measured outer diameter or the peripheral speed. There is a method for deriving the remaining amount of the recording medium. As another method, for example, Patent Document 1 discloses a technique of continuously providing a defective portion at one end of a roll-shaped print medium and deriving the remaining amount of the print medium by sensing the defective portion. Yes.

JP 2012-176522 A

  However, when the lead-out member is brought into contact with the recording medium, the recording medium may become dirty or damaged. Further, in order to derive the remaining amount using the defective portion, a special roll-shaped recording medium provided with the defective portion must be used. Therefore, there has been a demand for a method capable of deriving the remaining amount of the roll-shaped recording medium by a simple method without causing damage such as dirt or scratches on the recording medium.

  The present invention is for solving the above-described problems, and is a roll-shaped recording medium suitable for deriving the remaining amount of the roll-shaped recording medium by a simple method while preventing damage to the recording medium. It is an object to provide a remaining amount deriving device, a roll-shaped recording medium supply device, a roll-shaped recording medium remaining amount deriving method, and a program.

In order to achieve the above object, a remaining amount deriving device for a roll-shaped recording medium according to the present invention includes:
An image forming recording medium is unwound from a holding unit that rotatably holds a roll-shaped recording medium wound in a roll shape, and is conveyed to the recording medium that is conveyed to the image forming unit that forms an image on the recording medium. Acquisition means for acquiring the position of the tension roller for applying tension to the sensor by a predetermined sensor;
Deriving means for deriving the remaining amount of the roll-shaped recording medium held by the holding means based on the position of the tension roller acquired by the acquiring means;
Is provided.
In order to achieve the above object, a roll recording medium supply apparatus according to the present invention comprises:
Holding means for rotatably holding a roll-shaped recording medium in which a recording medium for image formation is wound in a roll;
A transport unit that transports the recording medium unwound from the holding unit along a predetermined transport path, and supplies the recording medium to an image forming unit that forms an image on the recording medium;
An acquisition unit that acquires, by a predetermined sensor, a position of a tension roller that applies tension to the recording medium conveyed to the image forming unit by the conveyance unit;
Deriving means for deriving the remaining amount of the roll-shaped recording medium held by the holding means based on the position of the tension roller acquired by the acquiring means;
Is provided.
In order to achieve the above object, the method for deriving the remaining amount of the roll-shaped recording medium according to the present invention includes:
An image forming recording medium is unwound from a holding unit that rotatably holds a roll-shaped recording medium wound in a roll shape, and is conveyed to the recording medium that is conveyed to the image forming unit that forms an image on the recording medium. An acquisition step of acquiring a position of a tension roller that applies tension to the sensor by a predetermined sensor;
Deriving step of deriving the remaining amount of the roll-shaped recording medium held by the holding unit based on the position of the tension roller acquired by the acquiring step;
including.
In order to achieve the above object, a program according to the present invention provides:
On the computer,
An image forming recording medium is unwound from a holding unit that rotatably holds a roll-shaped recording medium wound in a roll shape, and is conveyed to the recording medium that is conveyed to the image forming unit that forms an image on the recording medium. An acquisition function for acquiring the position of the tension roller for applying tension to the sensor by a predetermined sensor;
A derivation function for deriving the remaining amount of the roll-shaped recording medium held by the holding unit based on the position of the tension roller acquired by the acquisition function;
Is realized.

  According to the present invention, a roll recording medium remaining amount deriving device and a roll recording medium supply device suitable for deriving the remaining amount of the roll recording medium by a simple method while preventing damage to the recording medium. It is possible to provide a method and program for deriving the remaining amount of a roll-shaped recording medium.

It is a figure which shows the structure of the paper feeder to which the residual amount derivation device concerning Embodiment 1 of the present invention is applied. 2 is a cross-sectional view for explaining an internal configuration of the image forming apparatus. FIG. FIG. 3 is a block diagram for explaining a configuration related to control of the image forming apparatus. It is a block diagram for demonstrating the schematic structure of a residual amount derivation | leading-out apparatus. (A), (b) is a figure for demonstrating the outline | summary of derivation | leading-out of the residual amount which a residual amount derivation | leading-out apparatus performs. 3 is a flowchart showing a flow of processing executed in the image forming apparatus. 3 is a flowchart illustrating a flow of processing executed in the remaining amount derivation device according to the first embodiment. 6 is a flowchart illustrating a flow of processing relating to derivation of the remaining amount of roll paper. It is a figure which shows the example of the correspondence of the position of a tension roller, and the residual amount of roll paper. It is a flowchart which shows the flow of the process which concerns on adjustment of the unwinding rotation speed per unit time. 6 is a flowchart showing a flow of processing executed in the remaining amount deriving device according to the second embodiment. 6 is a flowchart showing a flow of processing relating to adjustment of roll paper tension. It is a figure which shows the structure of the paper feeding apparatus when derivation | leading-out of residual amount is performed using a distance sensor.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

  The embodiments described below are for illustrative purposes and do not limit the scope of the present invention. Accordingly, those skilled in the art can employ embodiments in which the following components are replaced with equivalent ones, and these embodiments are also included in the scope of the present invention. Further, in the following description, in order to facilitate understanding of the present invention, description of known unimportant technical matters is appropriately omitted.

(Embodiment 1)
FIG. 1 shows a configuration of a sheet feeding device to which a remaining amount derivation device according to Embodiment 1 of the present invention is applied. The remaining amount deriving device 100 according to the first embodiment is mounted on the paper feeding device 1 for supplying the roll paper 3 as a recording medium for image formation to the image forming device 2, and the image forming device 2 from the paper feeding device 1. The remaining amount of roll paper 3 that can be supplied to is derived.

  The paper feeding device 1 is a supply device that supplies roll paper 3 to the image forming device 2 as a recording medium for image formation. The paper feeding device 1 continuously unwinds the roll paper 3 in which the paper is wound in a roll shape around a predetermined winding core (paper tube) and conveys the roll paper 3 to the image forming apparatus 2. More specifically, the sheet feeding device 1 includes a holding unit (unwinder) 8 and a conveying unit 10 therein, and further includes a winding unit (rewinder) 9 thereon.

  The holding unit (unwinder) 8 is a member for holding the roll paper 3 to be supplied to the image forming apparatus 2. The holding unit 8 includes a rotatable rotating shaft (shaft) that holds the roll paper 3 through the winding core at the winding center of the roll paper 3, and a support base that supports the rotating shaft. The paper 3 is held rotatably.

  The holding unit 8 is equipped with a motor (not shown) for rotating the rotating shaft. The holding unit 8 rotates the rotating shaft of the holding unit 8 at the number of rotations per unit time (the number of rotations per unit time) instructed by driving of the motor, and unwinds the roll paper 3 being held. Can be sent out to the transport unit 10.

  The transport unit 10 transports the roll paper 3 unwound from the holding unit 8 along a predetermined transport path and supplies it to the image forming apparatus 2. Specifically, the transport unit 10 includes a tension roller 12, a driven roller 13, a paper set unit 14, a paper transport roller pair 15, an auto cutter 16, and a main body entrance transport roller pair 17.

  The tension roller 12 is installed immediately after the holding unit 8 in the transport unit 10 and controls so that the roll paper 3 sent out from the holding unit 8 does not sag. The tension roller 12 is installed so as to be movable in the vertical direction, and is moved vertically downward by its own weight or a force of a spring or the like to give a back tension to the roll paper 3 being conveyed. Due to the function of the tension roller 12, the tension applied to the roll paper 3 is kept constant, and the conveyance of the roll paper 3 is stabilized.

  The driven roller 13 is a roller that rotates around a predetermined rotation axis whose position is fixed following the conveyance of the roll paper 3. The driven roller 13 is disposed downstream of the tension roller 12 in the conveyance path, and plays a role of adjusting the conveyance direction of the roll paper 3.

  The paper setting unit 14 is a unit prepared for an operator to set paper. The paper set unit 14 is integrally formed with a member that holds a roller on one side of the paper transport roller pair 15 and is opened and closed together with the paper transport roller pair 15 by an operator.

  The paper transport roller pair 15 is a member for transporting the roll paper 3 set by the paper set unit 14 to the subsequent transport mechanism. The paper conveyance roller pair 15 is driven by a motor (not shown), conveys the roll paper 3 set by the paper setting unit 14 while being sandwiched, and supplies it to the auto cutter 16 and the main body entry conveyance roller pair 17.

  The auto cutter 16 is a member for cutting the roll paper 3 as necessary. The auto cutter 16 cuts the end of the roll paper 3 when the roll paper 3 having a length necessary for image formation in the image forming apparatus 2 has been transported, for example.

  The main body entering and conveying roller pair 17 is a member for conveying the roll paper 3 into the image forming apparatus 2. The main body entrance conveyance roller pair 17 is driven by a motor (not shown), conveys the roll paper 3 supplied from the paper conveyance roller pair 15 at the time of clamping, and supplies it to the image forming apparatus 2.

  The operation of setting the roll paper 3 will be described in detail. The operator pulls the roll paper 3 out of the holding unit 8, passes under the tension roller 12, and puts the roll paper 3 to the opened paper setting unit 14. Pulled out and sandwiched between the pair of paper transport rollers 15. When the paper set unit 14 is closed in this state, the set roll paper 3 is detected by an appropriate sensor, and the paper transport roller pair 15 is rotationally driven. Then, the set roll paper 3 is sent to the main body entering / conveying roller pair 17 through the auto cutter 16 and is set at a standby position (home position) immediately before entering the image forming apparatus 2.

  On the other hand, a winding unit (rewinder) 9 installed on the sheet feeding device 1 is a member for winding and holding the roll paper 3 discharged from the image forming apparatus 2. As with the holding unit 8, the winding unit 9 includes a rotatable winding shaft (shaft) that holds the roll paper 3 through the winding core (paper tube) at the winding center of the roll paper 3, and the winding unit 9. The roll paper 3 is rotatably held by a support base that supports the shaft.

  A motor (not shown) for rotating the winding shaft is mounted on the winding unit 9. By driving the motor, the winding unit 9 rotates the winding shaft at the instructed number of rotations per unit time, and winds the roll paper 3 fed from the image forming apparatus 2 via the driven roller 18. .

  The sheet feeding device 1 also includes a position sensor 11 s that measures the position of the tension roller 12 installed around the tension roller 12, and a remaining amount that derives the remaining amount of the roll paper 3 based on the measurement result of the position sensor 11 s. A deriving device 100.

  The position sensor 11 s is a sensor that can measure the position of the tension roller 12 that changes according to the deflection of the roll paper 3 without contacting the tension roller 12 and the roll paper 3 being conveyed. For example, the position sensor 11s is configured by a set of a light emitting element 11a and a light receiving element 11b arranged to face each other so as to sandwich the range in which the tension roller 12 moves.

  For example, in FIG. 1, three sets of the light emitting element 11a and the light receiving element 11b move in the moving direction 12d in which the tension roller 12 moves to apply tension to the roll paper 3 being conveyed, that is, vertically downward in the example of FIG. Arranged at different heights along. Information on whether the position of the tension roller 12 is above or below the line where the two elements face each other by determining whether the light emitted from the light emitting element 11a is received by the light receiving element 11b without being blocked. Is obtained. By performing such discrimination for each set of the light emitting element 11a and the light receiving element 11b, the position of the tension roller 12 is evaluated stepwise. Further, not only the tension roller 12 but also the roll paper 3 in the vicinity of the tension roller 12 that is tensioned by the tension roller 12 may be included to block the light emitted from the light emitting element 11a.

  Based on the position of the tension roller 12 measured by the position sensor 11s, the remaining amount deriving device 100 derives the remaining amount of the roll paper 3 held by the holding unit 8. Details of the remaining amount derivation process will be described later.

  The image forming apparatus 2 is placed on the sheet feeding apparatus 1 and outputs image data to be image-formed on the roll paper 3 supplied from the sheet feeding apparatus 1. The image forming apparatus 2 is, for example, a label printer, and can perform image formation of image data over a relatively large area without using a paper break, using the roll paper 3 continuously supplied from the paper feeding apparatus 1 as a recording medium. it can.

  The internal configuration of the image forming apparatus 2 will be described with reference to FIG. Hereinafter, the image forming apparatus 2 will be described using an electrophotographic and secondary transfer tandem color printer as an example. The image forming apparatus 2 includes an image forming unit 20, an intermediate transfer belt unit 30, a fixing device 40, and the like.

  The image forming unit 20 has a configuration in which four image forming units 21 (21k, 21c, 21m, 21y) are installed in series. The three image forming units 21c, 21m, and 21y on the upstream side (the right side in FIG. 2) of the four image forming units 21 are subtractive mixed primary colors cyan (C), magenta (M), and yellow, respectively. A color image is formed with the color toner (Y). On the other hand, the image forming unit 21k on the downstream side (left side in FIG. 2) forms a monochrome image using black (K) toner mainly used for dark portions of characters and images.

  Each image forming unit 21 includes a photosensitive drum 22 at the bottom. The peripheral surface of the photosensitive drum 22 is made of, for example, an organic photoconductive material. In the vicinity of the photosensitive drum 22, a cleaner 23, a charging roller 24, an optical writing head 25, and a developing roller 27 of the developing device 26 are disposed so as to surround the peripheral surface.

  The developing device 26 stores black (K), cyan (C), magenta (M), or yellow (Y) toner in a toner container installed at the upper portion, and supplies toner to the lower portion at the middle portion. A mechanism is provided, and the developing roller 27 described above is provided in the side opening at the lower part. The developing device 26 further includes a toner stirring member, a toner supply roller that supplies toner to the developing roller 27, a doctor blade that regulates the toner layer on the developing roller 27 to a constant layer thickness, and the like.

  In FIG. 2, only the configuration of the image forming unit 21k for black (K) is given a reference numeral, but each image forming unit 21 has the same configuration except for the color of the toner stored in the toner container. .

  The intermediate transfer belt unit 30 has an endless transfer belt 31 extending in a flat loop shape from substantially the left and right sides in FIG. A driving roller 32 and a driven roller 33 are provided which circulate and move the transfer belt 31 counterclockwise in FIG. The transfer belt 31 conveys the toner image directly transferred (primary transfer) to the belt surface to a transfer position to the roll paper 3 for transfer (secondary transfer) to the roll paper 3.

  The intermediate transfer belt unit 30 includes four primary transfer rollers 34 corresponding to the four image forming units 21k, 21c, 21m, and 21y in the loop of the transfer belt 31. The primary transfer rollers 34 are each composed of a conductive foam sponge that presses against the lower peripheral surface of the photosensitive drum 22 via the transfer belt 31, and rotates at an instructed rotation period. The drum 22 is brought into contact with or separated from the photosensitive drum 22.

  The standby conveyance roller pair 35 receives the roll paper 3 conveyed from the paper feeding device 1 and conveys the received roll paper 3 to the secondary transfer roller 36. The secondary transfer roller 36 is disposed so as to come into pressure contact with the driven roller 33 via the transfer belt 31, and secondary transfer the toner image transferred on the belt surface of the transfer belt 31 to the roll paper 3. A transfer part is formed.

  The fixing device 40 is disposed downstream (upward in FIG. 2) of the secondary transfer roller 36. The fixing device 40 includes a heating roller 42 with a built-in heater 41, and a pressure roller 43 that is in pressure contact with the heating roller 42.

  Further, on the further downstream side of the fixing device 40, the roll paper 3 on which the toner image has been fixed is carried out from the fixing device 40, and further discharged to a discharge tray formed on the upper surface of the image forming device 2. A roller pair 44 is provided. The roll paper 3 discharged through the paper discharge roller pair 44 is supplied to the winding unit 9 via the driven roller 18 installed on the side of the image forming apparatus 2.

  Next, a configuration related to control of the image generation apparatus 2 will be described with reference to FIG.

  The image forming apparatus 2 is connected to the host computer 5 and the remaining amount deriving device 100 installed in the paper feeding device 1 via a network such as a LAN (Local Area Network) or a USB (Universal Serial Bus).

  The image forming apparatus 2 includes a control unit 50 and a printing unit 60. More specifically, the control unit 50 includes a CPU (Central Processing Unit) 51, a LAN communication unit 52, a USB communication unit 53, a panel control unit 54, an operation panel 55, a storage device 56, a storage device control unit 57, and command analysis. Part 58 is provided. The printing unit 60 includes a printing control unit 61 and a printing mechanism unit 62.

  The CPU 51 is connected to each unit of the image forming apparatus 2 via a system bus that is a transmission path for transferring commands and data, and controls the operation of each unit of the image forming apparatus 2. The CPU 51 reads various programs such as system software stored in the ROM and the storage device 56 and executes them appropriately while using a ROM (Read Only Memory) and a RAM (Random Access Memory) (not shown) as work memories.

  The LAN communication unit 52 and the USB communication unit 53 communicate with external devices via the LAN and USB, respectively. For example, the CPU 51 communicates with the host computer 5 and the remaining amount derivation device 100 via the LAN communication unit 52 or the USB communication unit 53 to receive a print job transmitted from the host computer 5 or A transport request for the roll paper 3 is transmitted.

  The panel control unit 54 is connected to a display panel such as an LCD (Liquid Crystal Display) and an operation panel 55 including input devices such as various operation buttons. The panel control unit 54 displays various images, characters, symbols, and the like on the operation panel 55 under the control of the CPU 51. Further, the panel control unit 54 accepts various operations from the user input to the operation panel 55 and supplies operation signals corresponding to the accepted various operations to the CPU 51.

  The display device and the input device of the operation panel 55 may be configured by a so-called touch panel (touch screen) arranged so as to overlap each other.

  The storage device 56 is configured by a nonvolatile memory such as an EEPROM (Electrically Erasable Programmable ROM), an HDD (Hard Disk Drive), or the like, and stores various programs and data necessary for the operation of the image forming apparatus 2. Under the control of the CPU 51, the storage device control unit 57 writes data to the storage device 56 and controls reading of data stored in the storage device 56.

  The command analysis unit 58 analyzes commands included in the print data transmitted from the host computer 5 under the control of the CPU 51, and converts the print data into bitmap image data. Then, the command analysis unit 58 develops the converted bitmap image data in the corresponding storage area of the frame memory for each of black (K), magenta (M), cyan (C), and yellow (Y). The image data expanded in the frame memory is output to the print control unit 61.

  The print control unit 61 controls the print mechanism unit 62 including the image forming unit 20, the intermediate transfer belt unit 30, the fixing device 40 and the like under the control of the CPU 51, and according to the image data generated by the command analysis unit 58. Perform the printing process. For example, the print control unit 61 is driven to rotate the intermediate transfer belt unit 30 up and down and to rotate the transfer belt 31, and the drive roller 32, the standby conveyance roller pair 35, the discharge roller pair 44, and the like. Control for driving the transport mechanism, control for applying a voltage to the rotation drive system, and the like are performed.

  Next, the configuration of the remaining amount deriving device 100 arranged in the paper feeding device 1 will be described with reference to FIG. The remaining amount derivation device 100 includes a control unit 110, a storage unit 120, and a communication unit 130.

  The control unit 110 includes, for example, a CPU and a RAM that functions as a main memory of the CPU. The control unit 110 is connected to each unit of the remaining amount deriving device 100 via a system bus that is a transmission path for transferring commands and data, and controls the entire remaining amount deriving device 100. The control unit 110 may partially include a dedicated circuit such as an ASIC (Application Specific Integrated Circuit).

  The storage unit 120 includes a storage device such as a ROM or a flash memory. The storage unit 120 stores various programs and data used by the control unit 110 to perform various processes, and various data generated or acquired by the control unit 110 performing various processes. For example, the storage unit 120 stores information on the derived remaining amount of the roll paper 3, information on linear velocity at which the roll paper 3 should be transported in the transport unit 10, and the like.

  The communication unit 130 communicates with the image forming apparatus 2 connected via a LAN, USB, or the like under the control of the control unit 110. For example, the communication unit 130 receives a request for transporting the roll paper 3 transmitted from the image forming apparatus 2 in response to an image formation instruction, and displays an image to that effect when the remaining amount of the roll paper 3 is insufficient. A transmission process for transmitting to the forming apparatus 2 is performed.

  The control unit 110 functions as, for example, a remaining amount deriving unit 111, a conveyance control unit 112, and an unwinding control unit 113.

  The remaining amount deriving unit 111 acquires the position of the tension roller 12 for applying tension to the roll paper 3 unwound from the holding unit 8 and conveyed to the image forming apparatus 2 by measurement of the position sensor 11s. Then, the remaining amount deriving unit 111 derives the remaining amount of the roll paper 3 held by the holding unit 8 based on the acquired position of the tension roller 12.

  More specifically, the remaining amount deriving device 100 derives the remaining amount of the roll paper 3 held in the holding unit 8 as shown in FIG.

  When the amount of roll paper 3 remaining in the holding unit 8 is reduced when the roll paper 3 is drawn out from the holding unit 8, the outer diameter (winding diameter) of the roll paper 3 wound around the holding unit 8 is reduced. The position where the roll paper 3 is unwound from the outer periphery also moves to a lower position. On the other hand, the position of the tension roller 12 is determined by the magnitude of tension applied to the roll paper 3 being conveyed by the tension roller 12, and is located at a distance P from the unwinding position of the roll paper 3. For this reason, when the remaining amount of the roll paper 3 decreases and the unwinding position of the roll paper 3 moves, the position of the tension roller 12 also moves accordingly.

  That is, as shown in FIG. 5A, for example, when a new roll paper 3 is just installed in the holding unit 8 and the remaining amount of the roll paper 3 is large, the outer diameter of the roll paper 3 is large. Remains relatively high. On the other hand, as shown in FIG. 5B, the outer diameter of the roll paper 3 becomes smaller as the remaining amount of the roll paper 3 held by the holding unit 8 becomes smaller, so the tension roller 12 moves to a lower position, that is, moves. Move in direction 12d. Therefore, the remaining amount deriving unit 111 derives the remaining amount of the roll paper 3 held by the holding unit 8 based on the position of the tension roller 12.

  On the other hand, the conveyance control unit 112 in FIG. 4 controls the conveyance of the roll paper 3 in the conveyance unit 10. For example, the conveyance control unit 112 may drive the roller pair that can be driven in the conveyance unit 10, that is, the sheet conveyance roller pair 15 and the main body entry so that the roll paper 3 fed out from the holding unit 8 is conveyed at a designated conveyance speed. The drive of the conveyance roller pair 17 is controlled.

  The unwinding control unit 113 controls unwinding of the roll paper 3 from the holding unit 8. For example, the unwinding control unit 113 rotates the rotating shaft of the roll paper 3 held by the holding unit 8 to unwind the roll paper 3 from the holding unit 8. In addition, the unwinding control unit 113 determines the unit according to the amount of the roll paper 3 remaining in the holding unit 8 so that the speed at which the roll paper 3 is unwound from the holding unit 8 matches the conveyance speed in the conveyance unit 10. Adjust the number of revolutions per hour. Details of the process for adjusting the number of revolutions per unit time will be described later.

  The processing flow of the image forming apparatus 2 and the remaining amount deriving device 100 as described above will be described with reference to flowcharts.

  First, the flow of processing executed in the image forming apparatus 2 will be described with reference to the flowchart shown in FIG.

  The process of the flowchart of FIG. 6 is started in response to the control unit 50 of the image forming apparatus 2 receiving a print job (step S11). For example, the control unit 50 receives a print job including print data and other print setting conditions transmitted from the host computer 5 via the LAN control unit 52 or the USB control unit 53. The control unit 50 analyzes the received print job by the command analysis unit 58, generates image data from the print data included in the print job, develops the image data in the frame memory, and sets setting condition information necessary for the print processing. get.

  When receiving the print job, the control unit 50 subsequently transmits a transport request for the roll paper 3 to the paper feeding device 1 (step S12). That is, the control unit 50 transmits a request for supplying the roll paper 3 for outputting the image data and executing printing to the sheet feeding device 1 via the LAN control unit 52 or the USB control unit 53.

  This transport request includes information on the amount (length) of the roll paper 3 necessary for printing. That is, the control unit 50 calculates the length of the roll paper 3 necessary for printing from the area of the image data generated from the received print data, and sends a transport request including the calculated length of the roll paper 3 to the paper feeding device. 1 to send.

  When the transport request is transmitted to the paper feeding device 1, the control unit 50 determines whether or not a notification indicating that the requested amount of roll paper 3 cannot be transported has been received from the paper feeding device 1 (step S13). When notified that the conveyance is not possible (step S13; YES), the control unit 50 notifies the operator that the instructed printing cannot be performed, and waits until printing is possible (step S14).

  For example, as will be described in detail later, when the amount of roll paper 3 requested to be transported does not remain in the paper feed device 1, the paper feed device 1 indicates that the remaining amount of roll paper 3 is insufficient. The forming apparatus 2 is notified. In step S13, the control unit 50 determines whether or not printing can be started by determining whether or not such a notification has been received.

  When the amount of roll paper 3 necessary for image formation is not in the paper feeding device 1, the control unit 50 sends a message to the operation panel 55 urging the operator to replenish the paper feeding device 1 with the roll paper 3. By displaying or sending the print job to the host computer 5 that is the transmission source of the print job, the operator is informed that printing cannot be performed. The control unit 50 receives the notification from the paper feeding device 1 that the roll paper 3 is replenished to the holding unit 8 of the paper feeding device 1 and the amount of roll paper 3 necessary for printing can be conveyed. Wait without starting execution of printing.

  When there is no notification that the roll paper 3 cannot be conveyed (step S13; NO), or when printing is possible after the process of step S14, the image forming process proceeds to step S15, and the control unit 50 supplies the paper. Image formation is executed on the roll paper 3 supplied from the apparatus 1 (step S15). That is, the control unit 50 uses the image forming unit 20, the intermediate transfer belt unit 30, the fixing device 40, and the like included in the image forming apparatus 2 to roll paper 3 conveyed from the paper feeding device 1 to the image forming device 2. The image data generated by the command analysis unit 58 is sequentially output.

  While executing the image formation, the control unit 50 determines whether or not a notification of the remaining amount of the roll paper 3 has been received from the paper feeding device 1 (step S16). When the remaining amount of the roll paper 3 is notified (step S16; YES), the control unit 50 presents the notified remaining amount of the roll paper 3 to the operator (step S17).

  That is, as will be described in detail later, the sheet feeding device 1 derives the amount of roll paper 3 remaining in the holding unit 8 at an appropriate timing and notifies the image forming device 2 of the amount. Therefore, in the image forming apparatus 2, each time the control unit 50 receives a notification of the remaining amount of the roll paper 3, the notified remaining amount is displayed on the operation panel 55, or the host computer that is the transmission source of the print job The remaining amount information of the roll paper 3 is notified to the operator.

  If there is no notification of the remaining amount of roll paper 3 (step S16; NO), or if the notified remaining amount of roll paper 3 is presented, the control unit 50 determines whether or not printing is finished (step S18). If the printing is not finished (step S18; NO), the image forming process returns to step S15. That is, the control unit 50 is instructed to perform a process of forming an image on the roll paper 3 supplied from the paper feeding device 1 and presenting the remaining amount of the roll paper 3 notified from the paper feeding device 1. Repeat until data printing is complete. When printing is finally finished (step S18; YES), the image forming process in the flowchart of FIG. 6 is finished.

  As described above, when the image forming apparatus 2 performs image formation on the roll paper 3 sequentially supplied from the paper feeding apparatus 1 and is notified of the remaining amount information of the roll paper 3 remaining in the paper feeding apparatus 1, The remaining amount information is presented to the operator.

  Next, a flow of processing executed in the remaining amount derivation device 100 provided in the paper feeding device 1 will be described with reference to a flowchart shown in FIG.

  The process of the flowchart of FIG. 7 starts in response to the control unit 110 of the remaining amount deriving device 100 receiving a transport request for the roll paper 3 from the image forming apparatus 2 (step S21). That is, the control unit 110 receives the transport request transmitted by the image forming apparatus 2 through the process of step S12 in the flowchart of FIG.

  When receiving the transport request, the control unit 110 subsequently extracts information on the amount (length) of the roll paper 3 necessary for printing from the transport request, and whether or not the requested amount of roll paper 3 can be transported. Is determined (step S22). If it is determined that conveyance is not possible (step S22; NO), the control unit 110 notifies the image forming apparatus 2 to that effect and waits until conveyance is possible (step S23).

  In order to determine whether or not the requested amount of roll paper 3 can be conveyed, the control unit 110 stores in the storage unit 120 information on the remaining amount of the roll paper 3 derived in the past by a remaining amount derivation method described later. Keep it. Then, in response to receiving the transport request from the image forming apparatus 2, the control unit 110 reads information on the remaining amount of the roll paper 3 from the storage unit 120 and compares it with the amount of roll paper requested to be transported. Thus, it is determined whether or not the remaining amount of the roll paper 3 included in the holding unit 8 is equal to or greater than the amount of roll paper to be conveyed.

  When the remaining amount of the roll paper 3 included in the holding unit 8 is insufficient, the control unit 110 notifies the image forming apparatus 2 to that effect, and the holding unit 8 is replenished with the roll paper 3 and can be transported. It waits without starting conveyance of the roll paper 3 until it becomes. Since conveyance of the roll paper 3 is started after confirming that it can be conveyed in this way, a printing error caused by a shortage of the roll paper 3 during printing of a particularly large area is prevented. can do.

  When it is determined that the roll paper 3 can be transported (step S22; YES), or when the roll paper 3 can be transported after the process of step S23, the remaining amount derivation process proceeds to step S24, and the transport control unit 112 And the unwinding control unit 113 convey the roll paper 3 at the designated conveyance speed (step S24). That is, the unwinding control unit 113 unwinds the roll paper 3 by rotating the rotation shaft of the holding unit 8, and the conveyance control unit 112 is configured to rotate the roller pair (the sheet conveyance roller pair 15 and the main body of the conveyance unit 10). The pair of entrance conveyance rollers 17) is driven to sequentially feed the roll paper 3 unwound from the holding unit 8 to the image forming apparatus 2.

  At this time, the conveyance control unit 112 rotationally drives each roller pair so as to convey the roll paper 3 at a constant linear velocity so that the conveyed roll paper 3 is not loosened or pulled too much. For example, in order to convey the roll paper 3 at the linear velocity V, it is necessary to rotate a roller having a diameter d at a rotational speed w = V / (π × d) per unit time. Considering the relationship between the diameter of the roller and the number of rotations per unit time, the conveyance control unit 112 controls the number of rotations per unit time for each roller pair to be driven, so that a constant conveyance speed is obtained. Then, the roll paper 3 is conveyed. The unwinding control unit 113 also rotates the rotation shaft of the holding unit 8 based on the amount of the roll paper 3 remaining in the holding unit 8 so that the roll paper 3 is unwound at a linear speed corresponding to the conveyance speed. Drive.

  Note that the information on the speed at which the roll paper 3 should be transported is included in the transport request transmitted from the image forming apparatus 2, and in response to receiving the transport request, the control unit 110 receives the transport request. Alternatively, information on the speed at which the roll paper 3 should be conveyed may be extracted. Alternatively, information on the speed at which the roll paper 3 should be transported is stored in advance in the storage unit 120 included in the paper feeding device 1, and the control unit 110 responds to the reception of the transport request from the storage unit 120. Information on the speed at which the roll paper 3 should be conveyed may be read.

  While the roll paper 3 is being conveyed, the control unit 110 determines whether or not it is time to derive the remaining amount of the roll paper 3 (step S25). This timing may be determined in advance as a timing suitable for acquiring the remaining amount and conveying it to the operator while the roll paper 3 is being conveyed. Alternatively, for example, an instruction from an operator may be received via the image forming apparatus 2 and the timing at which the instruction is received may be set as a timing at which the remaining amount of the roll paper 3 should be derived.

  When it is time to derive the remaining amount of roll paper 3 (step S25; YES), the remaining amount deriving unit 111 in the control unit 110 derives the remaining amount of roll paper 3 (step S26). Details of the process for deriving the remaining amount of roll paper 3 in step S26 will be described with reference to the flowchart of FIG.

  In the flowchart of FIG. 8, the remaining amount deriving unit 111 acquires the position of the tension roller 12 measured by the position sensor 11 s (step S <b> 261), and calculates the remaining amount of the roll paper 3 based on the acquired position of the tension roller 12. Derived (step S262). For example, the remaining amount deriving unit 111 is configured so that the remaining amount decreases as the position of the tension roller 12 moves in the vertically downward moving direction 12d according to the correspondence shown in FIG. 8, the remaining amount of the roll paper 3 remaining is evaluated.

More specifically, the remaining amount deriving unit 111 is based on the three heights H1 to H3 obtained by the combination of the three sets of light emitting elements 11a and the light receiving elements 11b as described below. The level of the remaining amount of the roll paper 3 is estimated stepwise.
(1) When the position X of the tension roller 12 is higher than the height H1, the remaining amount of the roll paper 3 in the holding unit 8 is sufficiently filled.
(2) When the position X of the tension roller 12 is lower than the height H1 and is higher than the height H2, the remaining amount of the roll paper 3 in the holding unit 8 is medium.
(3) When the position X of the tension roller 12 is lower than the height H2 and is higher than the height H3, the remaining amount of the roll paper 3 in the holding unit 8 is slightly less.
(4) When the position X of the tension roller 12 is lower than the height H3, the remaining amount of the roll paper 3 in the holding unit 8 is small.

  In order to facilitate understanding, the estimation of the remaining amount is described in four stages in FIG. 9, but the roll is divided into more stages depending on the accuracy of the position detectable by the position sensor 11s. It is also possible to accurately determine the remaining amount of the paper 3. For example, the more the pairs of light emitting elements 11a and light receiving elements 11b are arranged along the movement line of the tension roller 12, the more accurately the position of the tension roller 12 can be measured. The accuracy of derivation increases.

  In addition, the correspondence between the position of the tension roller 12 and the remaining amount of the roll paper 3 changes when roll paper or other roll-shaped recording media having different paper thicknesses or winding core diameters are used. sell. For example, when roll paper with a large core diameter is used, the roll diameter of the roll paper is larger even when the remaining amount is the same as when using roll paper with a small core diameter. Overrated. Therefore, a plurality of correspondence relationships between the ratio and the remaining amount as shown in FIG. 9 are prepared according to the thickness of the sheet and the type of the winding core, and stored in the storage unit 120 in advance. Then, by reading out the necessary correspondence from the storage unit 120 according to the recording medium used by the remaining amount deriving unit 111, it is possible to derive the remaining amount with respect to many types of roll-shaped recording media with high accuracy.

  When the remaining amount of the roll paper 3 is estimated, the remaining amount deriving unit 111 updates the remaining amount of the roll paper 3 stored in the storage unit 120 with the derived remaining amount of the roll paper 3 (step S263). After the remaining amount is updated in this way, when the control unit 110 receives a request for transporting the roll paper 3 from the image forming apparatus 2, the control unit 110 determines the amount required for image formation based on the updated new remaining amount. It is determined whether or not the roll paper 3 can be supplied.

  Then, the remaining amount deriving unit 111 transmits the remaining amount of the roll paper 3 derived through the communication unit 130 to the image forming apparatus 2 (step S264). For example, when the derived remaining amount of the roll paper 3 is equal to or less than a predetermined amount, the remaining amount deriving unit 111 notifies the operator of the near end of the roll paper 3 by transmitting information on the remaining amount to the image forming apparatus 2. To do. Then, the remaining amount derivation process shown in FIG. 8 ends. The transmitted information on the remaining amount of the roll paper 3 is presented to the operator by display on the operation panel 55 of the image forming apparatus 2 or the like. Thereby, the operator can know an appropriate timing when the roll paper 3 should be replenished.

  Returning to the flowchart of FIG. 7, when the remaining amount is derived by the remaining amount deriving unit 111 in step S <b> 26, the unwinding control unit 113 next roll paper 3 in the holding unit 8 based on the derived remaining amount. The unwinding rotation speed per unit time is adjusted (step S27). That is, the unwinding control unit 113 stably transports the roll paper 3 so that the speed at which the roll paper 3 is unwound is maintained at a constant unwinding speed even if the remaining amount of the roll paper 3 changes. In addition, the number of rotations per unit time when the roll paper 3 is unwound from the holding unit 8 is controlled. Details of the adjustment processing of the unwinding rotation speed per unit time of the roll paper 3 in step S27 will be described with reference to the flowchart of FIG.

  In the flowchart of FIG. 10, first, the unwinding control unit 113 calculates the diameter of the roll paper 3 remaining in the holding unit 8 based on the remaining amount of the roll paper 3 derived by the remaining amount deriving unit 111 (step S271). ). That is, since the outer diameter of the roll paper 3 wound in the roll shape in the holding unit 8 changes according to the remaining amount of the roll paper 3, the unwind control unit 113 controls the roll paper 3 derived immediately before. The diameter of the current roll paper 3 corresponding to the remaining amount is calculated.

More specifically, when the roll paper 3 having a thickness t is left around the core having a radius R, the cross-sectional area of the roll paper 3 in the plane perpendicular to the rotation axis is as follows. When the area is included, the circumference ratio can be expressed as π × R × R + t × L with π. For this reason, the diameter D of the roll paper 3 wound in a roll shape in the holding unit 8 is determined as shown in Expression (1). In accordance with such a relationship, the unwinding control unit 113, the length L of the roll paper 3 corresponding to the remaining amount derived by the remaining amount deriving unit 111, the radius R of the winding core, the thickness t of the roll paper 3, Based on the above, the diameter D of the roll paper 3 is calculated.
D = 2 × √ (R × R + t × L / π) (1)

  When the diameter of the roll paper 3 is calculated, the unwind control unit 113 then calculates the number of rotations per unit time for unwinding the roll paper 3 at a constant linear velocity (step S272). More specifically, when the diameter of the roll paper 3 wound around the holding unit 8 is D, the rotation speed W per unit time for the roll paper 3 to rotate at the outer peripheral speed V is W = V / (π × D), which is inversely proportional to the diameter D. Therefore, the unwinding control unit 113 sets the number of rotations per unit time of the rotating shaft of the holding unit 8 so that the outer peripheral speed V matches the speed at which the conveyance control unit 112 should convey the roll paper 3 in the conveyance unit 10. calculate.

  When the number of rotations per unit time is calculated, the unwinding control unit 113 sets the number of unwinding rotations per unit time in the holding unit 8 to the calculated number of rotations per unit time (step S273). That is, when the remaining amount of the roll paper 3 decreases, the diameter D of the roll paper 3 also decreases and the rotational speed per unit time to be set increases, so the unwinding control unit 113 sets the calculated roll paper 3 to the calculated diameter. The rotational speed per unit time of the rotating shaft in the holding unit 8 is increased to the calculated rotational speed per unit time so as to be inversely proportional. In this way, by feeding back the remaining amount of the roll paper 3 derived by the remaining amount deriving unit 111 and adjusting the unwinding rotation speed per unit time, the roll paper 3 is loosened or excessively tensioned. Therefore, the roll paper 3 can be stably conveyed.

  If the unwinding rotation speed per unit time is adjusted in step S27, or if the timing for deriving the remaining amount of roll paper 3 has not arrived in step S25 (step S25; NO), the conveyance control is performed. The unit 112 determines whether or not the conveyance is finished (step S28). That is, the transport control unit 112 transports the amount of roll paper 3 requested to be transported from the image forming apparatus 2 and determines whether or not the roll paper 3 is in a state immediately before being cut by the auto cutter 16. .

  More specifically, assuming that the length of the roll paper 3 requested to be conveyed from the image forming apparatus 2 is L, and the distance along the conveyance path from the auto cutter 16 to the main body entry conveyance roller pair 17 is L0, When the roll paper 3 set in the home position is conveyed by the length L-L0, the roll paper 3 is to be cut by the auto cutter 16. Therefore, the conveyance control unit 112 determines whether or not the conveyance is finished by determining whether or not the roll paper 3 has been conveyed by the length L−L0.

  If the conveyance control unit 112 determines that the conveyance is not finished (step S28; NO), the process of the remaining amount deriving device 100 returns to step S24. That is, the conveyance control unit 112 continues to convey the roll paper 3 unwound from the holding unit 8, and when the remaining amount derivation timing comes during that time, the remaining amount derivation process and the unit time of the rotation axis of the holding unit 8 The process for adjusting the number of unwinding revolutions is performed.

  When the conveyance is finally finished (step S28; YES), the control unit 110 cuts the roll paper 3 by the auto cutter 16 (step S29). Then, the control unit 110 drives the main body entering and conveying roller pair 17 to send the cut roll paper 3 to the image forming apparatus 2 to the end. Thereafter, the processing in the flowchart of FIG. 7 ends.

  As described above, the remaining amount deriving device 100 according to the first embodiment determines the position of the tension roller 12 for applying tension to the roll paper 3 that is unwound from the holding unit 8 and conveyed to the image forming apparatus 2. The holding unit 8 is obtained so that the remaining amount decreases as the position of the tension roller 12 acquired by the position sensor 11s moves in order to move the tension roller 12 to apply tension to the roll paper 3, that is, vertically downward. The remaining amount of the roll paper 3 to be held is derived.

  It is not necessary to bring the position sensor 11s for acquiring the position of the tension roller 12 into contact with the roll paper 3, and the remaining amount of the roll paper 3 is indirectly derived. Can be prevented. Further, the position of the tension roller 12 can be obtained by attaching a position sensor to an existing sheet feeding device, and the conventional members can be utilized as they are, so that the space and cost for deriving the remaining amount of the roll paper 3 are reduced. Can be saved.

(Embodiment 2)
Hereinafter, the remaining amount derivation device according to Embodiment 2 of the present invention will be described.

  The remaining amount deriving device 100 according to the first embodiment unwinds the roll paper 3 wound around the holding unit 8 at a constant unwinding speed, and tensions the roll paper 3 conveyed to the image forming apparatus 2. The position of the tension roller 12 that gives the pressure is acquired, and the remaining amount of the roll paper 3 held by the holding unit 8 is derived. In addition to this, the remaining amount deriving device 100 according to the second embodiment switches between driving and stopping of rotation when the roll paper 3 is unwound by rotating the rotating shaft of the holding unit 8, that is, the rotating shaft is intermittently moved. To control the amount of deflection of the roll paper 3 conveyed by the conveyance unit 10.

  With reference to the flowchart shown in FIG. 11, the flow of processing executed in the remaining amount deriving device 100 according to the second embodiment will be described.

  In the flowchart of FIG. 11, the control unit 110 of the remaining amount deriving device 100 executes the same processing as steps S <b> 21 to S <b> 27 in the processing executed by the remaining amount deriving device 100 according to the first embodiment.

  That is, when receiving a request for transporting the roll paper 3 from the image forming apparatus 2 (step S21), the control unit 110 determines whether the requested amount of roll paper 3 can be transported (step S22). If it is determined that the conveyance is not possible (step S22; NO), the fact is notified to the image forming apparatus 2 (step S23).

  On the other hand, when it is determined that the roll paper 3 can be transported (step S22; YES), or when the roll paper 3 can be transported after the processing of step S23, the transport control unit 112 and the unwind control unit 113 Then, the roll paper 3 is transported at the designated transport speed (step S24). Then, the control unit 110 determines whether or not it is time to derive the remaining amount of the roll paper 3 (step S25).

  When it is time to derive the remaining amount of roll paper 3 (step S25; YES), the remaining amount deriving unit 111 derives the remaining amount of roll paper 3 (step S26). Then, the unwinding control unit 113 adjusts the unwinding rotation speed per unit time of the roll paper 3 in the holding unit 8 so as to unwind the roll paper 3 at a constant linear velocity based on the derived remaining amount. (Step S27).

  As described above, while the roll paper 3 is conveyed by the same processing as in the first embodiment, the remaining amount deriving device 100 according to the second embodiment performs the adjustment of the unwinding rotation speed per unit time in step S27. Alternatively, when the timing for deriving the remaining amount of the roll paper 3 has not arrived at step S25 (step S25; NO), a process of adjusting the tension applied to the roll paper 3 being conveyed through the conveyance unit 10 is executed (step S25: NO). Step S30). Details of the process of adjusting the tension of the roll paper 3 in step S30 will be described with reference to the flowchart of FIG.

  In the flowchart of FIG. 12, the unwinding control unit 113 acquires the position of the tension roller 12 measured by the position sensor 11s, and determines whether or not the acquired position of the tension roller 12 is equal to or less than a predetermined lower limit (step S31). ). When the position of the tension roller 12 is equal to or less than the predetermined lower limit (step S31; YES), the unwinding control unit 113 stops the rotation of the rotation shaft in the holding unit 8 and conveys the roll paper 3 (step S32). ). On the other hand, when the position of the tension roller 12 has not reached the predetermined lower limit position (step S31; NO), the process of adjusting the tension of the roll paper 3 is not executed and the process of the flowchart of FIG.

  That is, the rotational speed per unit time of the rotating shaft in the holding unit 8 is adjusted so that the roll paper 3 is unwound at the transport unit 10 at a speed at which the roll paper 3 is transported. The roll paper 3 being conveyed becomes loose. Then, the tension roller 12 gradually moves in the moving direction 12d, that is, vertically downward to apply tension to the loose roll paper 3. Therefore, when the tension roller 12 moves to an allowable lower limit position, the unwinding control unit 113 stops the rotation drive for unwinding the roll paper 3 in the holding unit 8 and stops the roller pair ( The roll paper 3 is conveyed by driving the paper conveyance roller pair 15 and the main body entry conveyance roller pair 17).

  When the roll paper 3 is transported while the rotation of the rotation shaft in the holding unit 8 is stopped, the roll paper 3 being transported is pulled along with the driving of the roller pair of the transport unit 10, and the degree of looseness of the roll paper 3 is gradually increased. To decrease. Therefore, the position of the tension roller 12 gradually moves in the direction opposite to the moving direction 12d for applying tension to the roll paper 3, that is, vertically upward.

  In such a state that the roll paper 3 is conveyed while stopping the rotation driving of the unwinding, the unwinding control unit 113 further determines whether or not the position of the tension roller 12 that moves vertically upward is equal to or greater than a predetermined upper limit. Is discriminated (step S33). If the position of the tension roller 12 has not reached the predetermined upper limit position (step S33; NO), the process returns to step S32. That is, the unwinding control unit 113 continues to transport the roll paper 3 while stopping the rotation of the rotation shaft in the holding unit 8 until the position of the tension roller 12 reaches the upper limit position.

  When the position of the tension roller 12 finally reaches the predetermined upper limit position (step S33; YES), the unwinding control unit 113 resumes the rotation of the rotation shaft in the holding unit 8 (step S34), and the normal control unit 113 resumes normal rotation. The roll paper 3 is unwound from the holding unit 8 in the driving state. As described above, the unwinding control unit 113 according to the second embodiment switches between the rotation mode for rotating the rotation shaft in the holding unit 8 and the stop mode for stopping the rotation according to the position of the tension roller 12, and the roll being conveyed. The tension applied to the paper 3 is adjusted.

  Returning to the flowchart of FIG. 11, when the tension of the roll paper 3 is adjusted in step S30, the transport control unit 112 determines whether or not the transport is finished (step S28). If the conveyance is not finished (step S28; NO), the process of the remaining amount derivation device 100 returns to step S24, and the processes of steps S24 to S27 and step S30 are repeated until the conveyance is finished.

  That is, the unwinding control unit 113 intermittently rotates the rotation shaft of the holding unit 8 while repeating the rotation mode and the stop mode according to the position of the tension roller 12 while the roll paper 3 is being conveyed. Drive. Further, each time the remaining amount is derived, the remaining amount deriving unit 111 derives the remaining amount of the roll paper 3 based on the position of the tension roller 12. This derivation of the remaining amount is appropriate because it is based on the position of the tension roller 12 acquired by the position sensor 11s while the rotation shaft of the holding unit 8 that is intermittently driven is rotationally driven.

  When the conveyance is finally finished (step S28; YES), the control unit 110 cuts the roll paper 3 by the auto cutter 16 (step S29). Then, the process in the flowchart of FIG. 11 ends.

  As described above, in the remaining amount deriving device 100 according to the second embodiment, the position of the tension roller 12 acquired while the roll paper 3 is conveyed from the holding unit 8 to the image forming apparatus 2 is a predetermined lower limit position. When the following is reached, the rotation of the rotating shaft of the holding unit 8 is stopped to control the amount of deflection of the roll paper 3 being conveyed. On the other hand, the remaining amount deriving device 100 according to the second embodiment has the holding unit 8 based on the position of the tension roller 12 acquired when the rotating shaft of the holding unit 8 is rotationally driven to unwind the roll paper 3. In order to derive the remaining amount of the roll paper 3 held by the roller, even when the roll paper 3 is conveyed while the rotary shaft of the holding unit 8 is intermittently driven to rotate, the position of the tension paper 12 is used as an index. The remaining amount can be derived.

(Modification)
Although the embodiment of the present invention has been described above, the above embodiment is an example, and the scope of application of the present invention is not limited to this. That is, the embodiments of the present invention can be applied in various ways, and all the embodiments are included in the scope of the present invention.

  For example, in the above embodiment, the position sensor 11s is configured by a set of the light emitting element 11a and the light receiving element 11b, and the remaining amount deriving unit 111 determines whether or not the light emitted from the light emitting element 11a is blocked. As a result, the position of the tension roller 12 was obtained. However, in the present invention, as long as the position is measured without contacting the roll paper 3, the position of the tension roller 12 can be measured by another method.

  For example, the light emitting element 11 a is disposed at a position where light is incident from an oblique direction with respect to the moving line of the tension roller 12, and the light emitted from the light emitting element 11 a is wound on the roll paper 3 wound around the tension roller 12. You may make it reflect on the surface and receive reflected light with the light receiving element 11b. In this case, a plurality of light receiving elements 11b are arranged in the direction in which the light is reflected, and the reflected light is received by different light receiving elements 11b in accordance with a change in the position of the tension roller 12, so that the tension roller 12 The position can be measured.

  Alternatively, a distance sensor arranged in the moving direction 12d of the tension roller 12 with respect to the position of the tension roller 12 may measure the distance from the distance sensor to the tension roller 12. For example, as shown in FIG. 13, the distance sensor 11ss can be disposed directly below the tension roller 12 that moves up and down. The distance sensor 11ss emits light toward the tension roller 12, receives light reflected from the surface of the roll paper 3 wound around the tension roller 12, and measures the distance to the tension roller 12 based on the reflected light. To do.

  In this case, since the distance to the distance sensor 11 ss decreases as the position of the tension roller 12 decreases, the remaining amount deriving device 100 determines the remaining amount as the acquired distance decreases based on the distance acquired by measurement of the distance sensor 11 ss. The remaining amount of the roll paper 3 held in the holding unit 8 is derived so that the amount of the paper is reduced. By measuring the distance, the position of the tension roller 12 can be obtained with high accuracy, so that the remaining amount can be derived more precisely.

  Moreover, in the said embodiment, the roll paper 3 was the object of derivation | leading-out of residual amount. However, the target from which the remaining amount deriving device according to the present invention derives the remaining amount is not limited to a paper medium, and is wound and accommodated in a roll shape so that it can be unwound from the holding unit 8 of the sheet feeding device 1. As long as it is a recording medium, it may be a recording medium of other materials such as a film-shaped recording medium.

  In the above-described embodiment, the image forming apparatus 2 is an electrophotographic and secondary transfer tandem type color printer. However, the remaining amount deriving device and supply device for a roll-shaped recording medium according to the present invention are other types of printers, or other image forming apparatuses for forming an image on a roll-shaped recording medium such as a copying machine and a facsimile machine. It is also possible to configure so as to execute the above-described processing by connecting to the network.

  The remaining amount deriving device according to the present invention can be provided not only by providing a configuration for realizing the function according to the present invention as a remaining amount deriving device, but also by applying a program to an existing personal computer or information terminal device. It can also function as a device. That is, by applying a program for realizing each functional configuration by the remaining amount derivation device 100 exemplified in the above embodiment so that a CPU that controls an existing personal computer, an information terminal device, and the like can be executed, It can function as a remaining amount deriving device according to the invention. The remaining amount derivation method according to the present invention can be implemented using a remaining amount derivation device.

  Moreover, the application method of such a program is arbitrary. The program can be applied by being stored in a computer-readable storage medium such as a flexible disk, a CD (Compact Disc) -ROM, a DVD (Digital Versatile Disc) -ROM, or a memory card. Furthermore, the program can be superimposed on a carrier wave and applied via a communication medium such as the Internet. For example, the program may be posted on a bulletin board (BBS: Bulletin Board System) on a communication network and distributed. The program may be started and executed in the same manner as other application programs under the control of an OS (Operating System) so that the above-described processing can be executed.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to the specific embodiment which concerns, This invention includes the invention described in the claim, and its equivalent range It is. Hereinafter, the invention described in the scope of claims of the present application will be appended.

(Appendix 1)
An image forming recording medium is unwound from a holding unit that rotatably holds a roll-shaped recording medium wound in a roll shape, and is conveyed to the recording medium that is conveyed to the image forming unit that forms an image on the recording medium. Acquisition means for acquiring the position of the tension roller for applying tension to the sensor by a predetermined sensor;
Deriving means for deriving the remaining amount of the roll-shaped recording medium held by the holding means based on the position of the tension roller acquired by the acquiring means;
Comprising
An apparatus for deriving a remaining amount of a roll-shaped recording medium.

(Appendix 2)
The derivation means is the roll-shaped recording medium held by the holding means as the position of the tension roller acquired by the acquisition means moves in a direction in which the tension roller moves to apply the tension to the recording medium. The remaining amount of the roll-shaped recording medium held by the holding unit is derived so that the remaining amount of
The apparatus for deriving a remaining amount of a roll-shaped recording medium according to Supplementary Note 1, wherein:

(Appendix 3)
The predetermined sensor includes a light emitting element and a light receiving element arranged so as to sandwich a range in which the tension roller moves,
The acquisition means acquires the position of the tension roller by determining whether or not the light receiving element has received light emitted from the light emitting element.
The apparatus for deriving a remaining amount of a roll-shaped recording medium according to Supplementary Note 1 or 2, wherein:

(Appendix 4)
The predetermined sensor is a distance sensor arranged in a direction in which the tension roller moves with respect to the position of the tension roller,
The acquisition means acquires a distance from the predetermined sensor to the tension roller,
The deriving unit derives the remaining amount of the roll-shaped recording medium held by the holding unit based on the distance from the predetermined sensor acquired by the acquiring unit to the tension roller.
The apparatus for deriving a remaining amount of a roll-shaped recording medium according to Supplementary Note 1 or 2, wherein:

(Appendix 5)
An unwinding control unit for rotating the rotating shaft of the holding unit to unwind the recording medium from the holding unit;
The apparatus for deriving a remaining amount of a roll-shaped recording medium according to any one of Supplementary notes 1 to 4, wherein:

(Appendix 6)
The unwinding control unit is configured to maintain the roll-shaped recording medium held by the holding unit led out by the deriving unit so that the recording medium is unwound from the holding unit at a predetermined unwinding speed. Unwinding the recording medium by increasing the number of rotations per unit time of the rotating shaft of the holding means as the amount decreases.
The apparatus for deriving a remaining amount of a roll-shaped recording medium according to appendix 5, wherein:

(Appendix 7)
The unwinding control means includes
The diameter of the roll-shaped recording medium held by the holding means, the remaining amount of the roll-shaped recording medium held by the holding means derived by the derivation means, and the diameter of the winding core around which the roll-shaped recording medium is wound And a calculating means for calculating based on the thickness of the recording medium,
Setting means for setting the number of rotations per unit time of the rotating shaft of the holding means so as to be inversely proportional to the diameter of the roll-shaped recording medium calculated by the calculating means;
including,
The remaining amount deriving device for a roll-shaped recording medium according to appendix 5 or 6, characterized in that:

(Appendix 8)
Holding means for rotatably holding a roll-shaped recording medium in which a recording medium for image formation is wound in a roll;
A transport unit that transports the recording medium unwound from the holding unit along a predetermined transport path, and supplies the recording medium to an image forming unit that forms an image on the recording medium;
An acquisition unit that acquires, by a predetermined sensor, a position of a tension roller that applies tension to the recording medium conveyed to the image forming unit by the conveyance unit;
Deriving means for deriving the remaining amount of the roll-shaped recording medium held by the holding means based on the position of the tension roller acquired by the acquiring means;
Comprising
An apparatus for supplying a roll-shaped recording medium.

(Appendix 9)
An image forming recording medium is unwound from a holding unit that rotatably holds a roll-shaped recording medium wound in a roll shape, and is conveyed to the recording medium that is conveyed to the image forming unit that forms an image on the recording medium. An acquisition step of acquiring a position of a tension roller that applies tension to the sensor by a predetermined sensor;
Deriving step of deriving the remaining amount of the roll-shaped recording medium held by the holding unit based on the position of the tension roller acquired by the acquiring step;
including,
A method for deriving the remaining amount of a roll-shaped recording medium.

(Appendix 10)
On the computer,
An image forming recording medium is unwound from a holding unit that rotatably holds a roll-shaped recording medium wound in a roll shape, and is conveyed to the recording medium that is conveyed to the image forming unit that forms an image on the recording medium. An acquisition function for acquiring the position of the tension roller for applying tension to the sensor by a predetermined sensor;
A derivation function for deriving the remaining amount of the roll-shaped recording medium held by the holding unit based on the position of the tension roller acquired by the acquisition function;
To realize,
A program characterized by that.

DESCRIPTION OF SYMBOLS 1 ... Paper feeding apparatus, 2 ... Image forming apparatus, 3 ... Roll paper, 5 ... Host computer, 8 ... Holding part (unwinder), 9 ... Winding part (rewinder), 10 ... Conveying part, 11s ... Position sensor, 11a ... light emitting element, 11b ... light receiving element, 11ss ... distance sensor, 12 ... tension roller, 12d ... moving direction, 13 ... driven roller, 14 ... paper setting unit, 15 ... paper conveying roller pair, 16 ... auto cutter, 17 ... main body Incoming conveyance roller pair, 18 ... driven roller, 20 ... image forming unit, 21 (21k, 21c, 21m, 21y) ... image forming unit, 22 ... photosensitive drum, 23 ... cleaner, 24 ... charging roller, 25 ... optical writing 26 ... developing device, 27 ... developing roller, 30 ... intermediate transfer belt unit, 31 ... transfer belt, 32 ... drive roller, 33 ... driven roller, 34 Primary transfer roller, 35 ... standby conveyance roller pair, 36 ... secondary transfer roller, 40 ... fixing device, 41 ... heater, 42 ... heating roller, 43 ... pressure roller, 44 ... discharge roller pair, 50 ... control unit, 51 ... CPU, 52 ... LAN communication unit, 53 ... USB communication unit, 54 ... panel control unit, 55 ... operation panel, 56 ... storage device, 57 ... storage device control unit, 58 ... command analysis unit, 60 ... printing unit, DESCRIPTION OF SYMBOLS 61 ... Print control part, 62 ... Printing mechanism part, 100 ... Residual amount derivation device, 110 ... Control part, 111 ... Remaining quantity derivation part, 112 ... Conveyance control part, 113 ... Unwinding control part, 120 ... Storage part, 130 ... communication department

Claims (10)

An image forming recording medium is unwound from a holding unit that rotatably holds a roll-shaped recording medium wound in a roll shape, and is conveyed to the recording medium that is conveyed to the image forming unit that forms an image on the recording medium. Acquisition means for acquiring the position of the tension roller for applying tension to the sensor by a predetermined sensor;
Deriving means for deriving the remaining amount of the roll-shaped recording medium held by the holding means based on the position of the tension roller acquired by the acquiring means;
Comprising
An apparatus for deriving a remaining amount of a roll-shaped recording medium. The derivation means is the roll-shaped recording medium held by the holding means as the position of the tension roller acquired by the acquisition means moves in a direction in which the tension roller moves to apply the tension to the recording medium. The remaining amount of the roll-shaped recording medium held by the holding unit is derived so that the remaining amount of
The apparatus for deriving a remaining amount of a roll-shaped recording medium according to claim 1. The predetermined sensor includes a light emitting element and a light receiving element arranged so as to sandwich a range in which the tension roller moves,
The acquisition means acquires the position of the tension roller by determining whether or not the light receiving element has received light emitted from the light emitting element.
The remaining amount deriving device for a roll-shaped recording medium according to claim 1 or 2. The predetermined sensor is a distance sensor arranged in a direction in which the tension roller moves with respect to the position of the tension roller,
The acquisition means acquires a distance from the predetermined sensor to the tension roller,
The deriving unit derives the remaining amount of the roll-shaped recording medium held by the holding unit based on the distance from the predetermined sensor acquired by the acquiring unit to the tension roller.
The remaining amount deriving device for a roll-shaped recording medium according to claim 1 or 2. An unwinding control unit for rotating the rotating shaft of the holding unit to unwind the recording medium from the holding unit;
The apparatus for deriving a remaining amount of a roll-shaped recording medium according to any one of claims 1 to 4. The unwinding control unit is configured to maintain the roll-shaped recording medium held by the holding unit led out by the deriving unit so that the recording medium is unwound from the holding unit at a predetermined unwinding speed. Unwinding the recording medium by increasing the number of rotations per unit time of the rotating shaft of the holding means as the amount decreases.
The apparatus for deriving a remaining amount of a roll-shaped recording medium according to claim 5. The unwinding control means includes
The diameter of the roll-shaped recording medium held by the holding means, the remaining amount of the roll-shaped recording medium held by the holding means derived by the derivation means, and the diameter of the winding core around which the roll-shaped recording medium is wound And a calculating means for calculating based on the thickness of the recording medium,
Setting means for setting the number of rotations per unit time of the rotating shaft of the holding means so as to be inversely proportional to the diameter of the roll-shaped recording medium calculated by the calculating means;
including,
The remaining amount deriving device for a roll-shaped recording medium according to claim 5 or 6. Holding means for rotatably holding a roll-shaped recording medium in which a recording medium for image formation is wound in a roll;
A transport unit that transports the recording medium unwound from the holding unit along a predetermined transport path, and supplies the recording medium to an image forming unit that forms an image on the recording medium;
An acquisition unit that acquires, by a predetermined sensor, a position of a tension roller that applies tension to the recording medium conveyed to the image forming unit by the conveyance unit;
Deriving means for deriving the remaining amount of the roll-shaped recording medium held by the holding means based on the position of the tension roller acquired by the acquiring means;
Comprising
An apparatus for supplying a roll-shaped recording medium. An image forming recording medium is unwound from a holding unit that rotatably holds a roll-shaped recording medium wound in a roll shape, and is conveyed to the recording medium that is conveyed to the image forming unit that forms an image on the recording medium. An acquisition step of acquiring a position of a tension roller that applies tension to the sensor by a predetermined sensor;
Deriving step of deriving the remaining amount of the roll-shaped recording medium held by the holding unit based on the position of the tension roller acquired by the acquiring step;
including,
A method for deriving the remaining amount of a roll-shaped recording medium. On the computer,
An image forming recording medium is unwound from a holding unit that rotatably holds a roll-shaped recording medium wound in a roll shape, and is conveyed to the recording medium that is conveyed to the image forming unit that forms an image on the recording medium. An acquisition function for acquiring the position of the tension roller for applying tension to the sensor by a predetermined sensor;
A derivation function for deriving the remaining amount of the roll-shaped recording medium held by the holding unit based on the position of the tension roller acquired by the acquisition function;
To realize,
A program characterized by that.

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