JP2016175712A - Roll sheet feeding device, image formation apparatus and roll end detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roll sheet feeding device which detects a roll end correctly and quickly without adding a new mechanism inexpensively.SOLUTION: A roll sheet feeding device comprises: drive means 31; forward feeding mechanism 32 which transmits a drive force for delivering a sheet from a roll sheet from the drive means; roll sheet drive mechanism 33 which includes a load generation part 36 for applying a conveyance load to the sheet conveyed in the forward feeding direction from the roll sheet with a rotation load; rewinding mechanism 35 which rewinds the sheet to the roll sheet; and regeneration mechanism 34 which regenerates the drive force to the drive means with the sheet conveyed in the forward feeding direction. The rewinding mechanism and the regeneration mechanism are switchably provided in the rotation direction of the drive means, and the regeneration mechanism functions when the drive means rotates in the forward feeding direction and the rewinding mechanism functions when the drive means rotates in the rewinding direction to detect the presence/absence of the regeneration effect at the time of conveyance with the load change of the drive means.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a roll paper feeding device that transports paper carried out of roll paper, an image forming apparatus including the same, and a roll end detection method in the roll paper feeding device.

  In an image forming apparatus such as a copying machine or a printer using an inkjet method, a sheet is conveyed from a roll state medium (roll paper) accommodated therein, and an image is formed on the sheet using ink in an image forming unit. Printing is performed by repeatedly executing the operation.

  In addition, since there is a state where the rear end of the medium is bonded to the core tube and a state where it is not bonded at the roll end of the roll-shaped medium, an image forming apparatus equipped with a function for identifying these is also provided. Yes.

  Here, when the roll end is in a state in which the rear end of the medium is bonded to the core tube, printing is performed in a state where the medium is not conveyed, and therefore, there is a concern that paper jam occurs due to cockling due to repeated printing at the same place. In order to avoid this, accurate and prompt detection by the roll end detection mechanism is necessary.

  In addition, when a roll end with the roll media attached to the core tube is generated with the roll media set from above, a highly accurate roll end detection mechanism is installed. However, it is considered that the roll-shaped medium may be pulled out of the pedestal by being pulled by the bonded core tube, and the apparatus may be damaged.

  Therefore, for example, in Patent Documents 1 and 2, a roll end detection that detects a roll end by displacing a bearing that holds a support shaft inserted into the roll paper by a tensile force from a paper transport mechanism related to the support shaft. A mechanism is provided. That is, when the roll end is in a state where the rear end of the medium is bonded to the core tube, the roll paper core is pulled by an increase in the tensile force from the paper transport mechanism, and the displacement increases. On the other hand, the displacement is small when the remaining amount of roll paper is sufficient. A printer that detects the roll end by detecting the above displacement difference with a sensor is disclosed.

  Further, for example, Patent Document 3 is provided with a drive device that regenerates back tension. The roll medium rotates to apply back tension to the paper, and the drive source corresponds to back tension force. A roll paper feeding device in which driving force is regenerated is disclosed.

  However, in the mechanism in which the support portion of the roll-shaped medium is swung by the rear end of the medium bonded to the core tube, for example, the back tension for transporting the paper without skew cannot be urged constantly, Depending on the size and remaining amount of the medium, there are concerns about false detection. In addition, a cost increase due to a mechanism for realizing this and a machine layout space are required.

  In view of the above circumstances, an object of the present invention is to provide a roll paper supply device that detects a roll end accurately and quickly without adding a new mechanism at a low cost.

  In order to solve the above-described problem, according to one aspect of the present invention, a roll paper supply device that can feed paper from roll paper to an image forming unit that forms an image on the paper includes a driving unit, a progressive mechanism, and roll paper It has a drive mechanism, a rewinding mechanism, and a regeneration mechanism. The driving unit generates a driving force for conveying the paper. The progressive feed mechanism receives a driving force from the driving unit and transmits a driving force for feeding the paper from the roll paper from the driving unit. The roll paper drive mechanism generates a rotational load by a drive transmission unit that transmits a driving force to the roll paper and the paper that is conveyed in the forward feed direction, and the paper that is conveyed from the roll paper in the forward feed direction by the rotational load. Is provided with a load generating section for applying a transport load to the. The rewinding mechanism transports the paper in a direction opposite to the forward feeding direction, and rewinds the paper on the roll paper. The regenerative mechanism transmits the driving force existing in the roll paper driving mechanism, to which the driving force in the forward feeding direction is applied by the paper conveyed in the forward feeding direction from the roll paper, back to the forward feeding mechanism to the driving means. Regenerate driving force. The rewinding mechanism and the regenerative mechanism are provided so as to be switchable depending on the rotation direction of the driving means. When the drive means rotates in the forward feed direction, the regeneration mechanism functions, and when the drive means rotates in the rewind direction, the rewind mechanism functions. The presence or absence of a regenerative effect during conveyance is detected by a load fluctuation of the driving means.

  According to one aspect, in the roll paper supply device, the roll end can be detected accurately and promptly at low cost and without adding a new mechanism.

1 is a diagram illustrating a schematic configuration example of an image forming apparatus according to an embodiment. 1 is a schematic cross-sectional view illustrating a configuration example of an image forming apparatus according to an embodiment. It is the schematic which shows the positional relationship of the spool axis | shaft in a spool bearing stand in which roll paper is set, and a flange. FIG. 2 is an enlarged view around a registration roller in the image forming apparatus of FIG. 1. It is a figure which shows typically the structure of the drive device of the roll paper feeding apparatus which concerns on embodiment of this invention. It is a control block diagram of the roll paper feeding device according to the embodiment of the present invention. It is a perspective view which shows an example of the regeneration mechanism and rewinding mechanism of the drive device of the roll paper feeder which concerns on embodiment of this invention. It is a perspective view which expands and shows the periphery of the regeneration mechanism and rewinding mechanism in FIG. The linear velocity of the flange, the linear velocity of the paper feed roller, and the voltage of the drive motor when the roll paper having the paper rear end bonded to the core tube becomes the roll end are shown. The linear velocity of the flange, the linear velocity of the paper feed roller, and the voltage of the drive motor when the roll paper having the paper rear end bonded to the core tube becomes the roll end are shown. It is a flowchart which shows the conveyance control which concerns on embodiment of this invention. It is a detailed flowchart of the sequence after the adhesion roll end of FIG.

<Configuration of image forming apparatus>
An image forming apparatus according to an aspect of an embodiment of the present invention is an ink jet printer that performs printing on a recording medium by ejecting ink droplets corresponding to image data. However, the present invention conveys a recording medium and performs printing. The present invention can also be applied to an electrophotographic copying machine or a printing machine that performs the above.

  FIG. 1 is a perspective view of a schematic configuration example of an image forming apparatus 80 according to the present embodiment. FIG. 2 is a side sectional view of the image forming apparatus. Will be explained. 1, X indicates the depth direction (front-rear direction) of the image forming apparatus 80, Y indicates the width direction (main scanning direction) of the image forming apparatus 80, and Z indicates the up-down direction.

  In FIG. 1, an image forming apparatus 80 is an image forming apparatus of a serial liquid discharge method (ink discharge method), and a main body casing 81 is disposed on a main body frame 82. In the image forming apparatus 80, a main guide rod 64 and a sub guide rod 65 are stretched in a main body casing 81 in the main scanning direction indicated by a double arrow Y in FIG. The main guide rod 64 movably supports the carriage 66, and the carriage 66 is provided with a connecting piece 66 a that engages with the sub guide rod 65 to stabilize the posture of the carriage 66.

  In the image forming apparatus 80, an endless belt-like timing belt 67 is disposed along the main guide rod 64, and the timing belt 67 is stretched between a driving pulley 68 and a driven pulley 69. The driving pulley 68 is rotationally driven by the main scanning motor 70, and the driven pulley 69 is disposed in a state where a predetermined tension is applied to the timing belt 67. The drive pulley 68 is rotationally driven by the main scanning motor 70 to rotate and move the timing belt 67 in the main scanning direction according to the rotation direction.

  The carriage 66 is connected to a timing belt 67, and the carriage 66 reciprocates in the main scanning direction along the main guide rod 64 when the timing belt 67 is rotated in the main scanning direction by the drive pulley 68.

  In the image forming apparatus 80, a cartridge part 71 and a maintenance mechanism part 72 are detachably housed at both end positions in the main scanning direction in the main body casing 81. In the cartridge unit 71, cartridges 73 that respectively store yellow (Y), magenta (M), cyan (C), and black (K) inks are stored in a replaceable manner. Each cartridge of the cartridge unit 71 is connected to a recording head of a corresponding color of a recording head (not shown) mounted on the carriage 66 by a pipe (not shown), and from the cartridge unit 71 to the recording head of each color through the pipe. Supply ink.

  The image forming apparatus 80 intermittently moves on the platen 74 (see FIG. 2) in the sub-scanning direction (arrow Y direction in FIG. 1) perpendicular to the main scanning direction while moving the carriage 66 in the main scanning direction. An image is recorded on the paper P by ejecting ink onto the paper P conveyed to the paper.

  The paper P is not limited to paper, and various types of paper such as a roll film can be used. However, in the following description, the paper being transported is the paper P or paper for clarity of explanation. A roll state in which P is wound will be described as roll paper Pr (Pa, Pb), and a core tube (core part) of the roll paper Pr will be described as Ps.

  As shown in FIG. 2, the image forming apparatus 80 is provided with a chamber 75 in which a fan is disposed below the platen 74. When the fan is driven, the sheet P conveyed on the platen 74 is fed. The sheet is conveyed while being in close contact with the platen 74.

  The image forming apparatus 80 intermittently conveys the paper P in the sub-scanning direction, and is mounted on the carriage 66 while moving the carriage 66 in the main scanning direction while the conveyance of the paper P in the sub-scanning direction is stopped. Ink is discharged from the nozzle row of the recording head thus formed onto the paper P on the platen 74 to form (record) an image on the roll paper P.

  The maintenance mechanism 72 performs cleaning of the ejection surface of the recording head, capping, ejection of unnecessary ink, and the like to discharge unnecessary ink from the recording head and maintain the reliability of the recording head.

  In the image forming apparatus 80, an encoder sheet (not shown) is disposed in parallel with the timing belt 67 and the main guide rod 64 over at least the movement range of the carriage 66. An encoder sensor that reads an encoder sheet is attached to the carriage 66. The image forming apparatus 80 controls the movement of the carriage 66 in the main scanning direction by controlling the driving of the main scanning motor 70 based on the reading result of the encoder sheet by the encoder sensor.

  Further, both ends of the paper P conveyed to the image forming unit 60 are detected by a reflection type sensor (encoder sensor, paper front end detection sensor 77, see FIG. 6) mounted on the carriage 66. At that time, the front end of the paper is detected. The size of the paper P is detected from the position in the main scanning direction read by the sensor 77.

  In the image forming apparatus 80, a main body frame 82 that supports a main body casing 81 is provided with two spool bearing bases 5a and 5b in the vertical direction of FIGS. 1 and 2, as shown in FIGS. . The internal configuration of each spool bearing base 5a, 5b will be described in detail with reference to FIG.

  As shown by the arrows in FIG. 2, the paper P (rolled paper) P drawn from the leading edge of the roll paper Pr set on the spool bearing bases 5a and 5b is a pair of conveying rollers 6a and 6b, a registration roller 10 and a registration roller. It is conveyed in the conveyance path 9 by the pressure roller 17. Note that roll paper trays 8a and 8b for preventing the roll paper Pr from falling are provided below the roll paper Pr (Pa, Pb).

  The paper P passes through the transport path 9 supported by the medium transport guide members 18 a and 18 b and is transported onto the platen 74 in the image forming unit 60. When images are formed on both sides, the image is reversed by the reversing unit 19.

  In the image forming unit 60, an image is formed by the liquid recording head ejecting droplets of each color onto the paper P corresponding to the image data. In the forward conveyance direction discharge portion of the paper P on which the image is formed, a cutter 76 that extends in the sub-scanning direction (paper width direction) is used to cut the paper P made of continuous paper into a predetermined length. Is provided.

  In order to align the leading end of the conveyed paper P, the cutter 76 is fixed to a wire or timing belt that is stretched between a plurality of pulleys (one of which is connected to a drive motor). The sheet P is cut into a predetermined length by moving in the main scanning direction Y by the drive motor. The cut sheet P is discharged to the discharge unit.

  Here, FIG. 3 shows an enlarged view of the spool bearing bases 5a and 5b on which the roll paper Pr (Pa, Pb) is set. As shown in FIG. 3, the spool shaft 1 is held by two relay rollers (support rollers) 2 and 3 inside the spool bearing bases 5 a and 5 b. Further, a flange (flange member) 4 is provided at the end in the width direction of the rolled paper Pr in a rolled state.

  At this time, the sheet P is disposed so that the angle θ1 formed by the spool shaft 1 and the upper relay roller 2 is larger than the angle θ2 in the transport direction T when the sheet P is unloaded from the roll paper Pr. Yes. By arranging in this way, the roll paper Pr in which the paper P is bonded to the core tube Ps at the roll end when the winding amount of the paper P reaches the end is dropped from the holding position by the conveyance by the paper feed roller 6. Can be prevented.

  FIG. 4 shows an enlarged view around the registration roller 10. The registration roller 10 is rotationally driven by a registration motor 13 via a timing belt 12 and a timing pulley 11. Further, an encoder sheet (code wheel) 14 is attached to the shaft of the registration roller 10, and an encoder sensor 15 including a transmission type photosensor for detecting a pattern formed on the encoder sheet 14 is provided. The encoder sheet 14 and the encoder sensor 15 constitute a rotary encoder 16 that detects a movement amount and a movement position of the registration roller 10.

  The conveyance amount (rotation drive) of the registration roller 10 is read by a rotary encoder 16 including an encoder sheet 14 and an encoder sensor 15, and is controlled by the control unit 100 based on the read information.

  The registration roller 10 configured as described above is driven to rotate by the registration motor 13 and is in contact with the registration pressure roller 17 so that the registration roller 10 is rotated in the forward rotation direction. As a result, the paper P is pulled out from the roll paper Pr, and is transported in the direction on the platen 74 (forward transport direction) from the spool bearing bases 5a and 5b.

  Further, the registration roller 10 is rotated in the reverse direction (clockwise in FIG. 2) by the registration motor 13, thereby reversely conveying the paper P from the platen 74 in the spool bearing bases 5a and 5b (counter-conveying direction). Also used for

  Here, the forward feeding operation configured to feed the paper P from the roll paper Pr in the forward feeding direction from the roll paper feeding device 20 to the image forming unit 60 will be described.

  When the paper P is fed in the forward feed direction from the roll paper feeding device 20 to the image forming unit 60, the driving device 7 rotates forward, and the paper feeding roller 6 is rotated counterclockwise in FIG. The paper P is sent out from the roll paper Pr. When the paper P is sent out from the roll paper Pr, the relay rollers 2 and 3 rotate in the clockwise direction as the flange 4 and the spool shaft 1 attached to the roll paper Pr rotate in the counterclockwise direction. In FIG. 3, the relay rollers 2 and 3 and the spool shaft 1 are engaged with each other without idling. However, the relay rollers 2 and 3 and the spool shaft 1 may be engaged via a gear, or may be engaged via a rubber. Further, the slack of the paper P does not occur between the paper feed roller 6 and the roll paper Pr for the following reason.

  Here, during image formation, an image is formed on the paper P fed from the roll paper Pr while the carriage 66 moves in a direction perpendicular to the paper feed direction of the roll paper Pr. In order to move the image forming position, it is necessary to repeatedly move the paper P with respect to the carriage 66. Therefore, the roll paper feeding device 20 performs intermittent conveyance that repeats conveyance and stoppage every predetermined time. When the paper P is sent out from the roll paper Pr by carrying out intermittent conveyance, the rotation of the paper feed roller 6 is stopped so that the paper P does not loosen between the paper feed roller 6 and the spool shaft 1 when stopped. It is necessary to stop the rotation of the spool shaft 1 substantially at the same time or earlier than the rotation of the paper feed roller 6 is stopped.

  Therefore, when the paper is sent out from the roll paper Pr, it is performed while applying a braking force to the roll paper Pr via the relay rollers 2 and 3 and the spool shaft 1. As one method for applying a brake to the spool shaft 1, for example, the spool shaft 1 is braked by a torque limiter 36 (see FIG. 5), and the paper P is fed from the roll paper Pr in the braked state. Can do.

  In this way, the paper P transported from the paper feed roller 6 is transported to the paper transport path P. On the downstream side of the conveyance path 9, the paper P conveyed between the registration roller 10 and the registration pressure roller 17 shown in FIG. 2 is conveyed onto the platen 74. A negative pressure is formed in the chamber 75 by an intake fan disposed under the chamber 75, and the paper P is sucked onto the platen 74 by a plurality of holes provided in the platen 74, and the flatness of the paper P is maintained. Is done.

  Above the platen 74, a carriage 66 on which a head for ejecting ink is mounted is disposed. The carriage 66 reciprocates in the width direction of the paper along the main scanning direction, and the ink is supplied to the paper P on the platen 74. To form an image on the paper P. Each time the carriage 66 moves corresponding to the width of the head, the paper P is sent out by a predetermined length from the registration roller 10 (intermittent conveyance). When the image formation is completed, the paper P is cut into a predetermined length by the cutter 76. And discharged.

  Next, a rewinding operation for transporting the paper P in the rewind direction opposite to the forward feed direction and rewinding the paper P onto the roll paper Pr will be described.

  When the paper P is rewound from the image forming unit 60 toward the roll paper feeding device 20, the driving device 7 rotates in the reverse direction, and the paper feeding roller 6 is rotated clockwise in FIG. When the paper P is rewound, the one-way clutch 51a (see FIG. 7) transmits the driving force to the spool shaft 1, so that the spool shaft 1 rotates in the clockwise direction. Along with this, the roll paper Pr is also rotated in the clockwise direction, and the leading edge of the paper P that has been fed from the roll paper Pr is returned from the position of the cutter 76 to a predetermined standby position. Note that when the roll end of the roll paper Pr is no longer being rolled, the paper P (roll end) is rewound to the roll paper Pr as described later.

  The smaller the outer shape of the roll paper Pr, the smaller the winding amount per rotation. The relative sizes of the rotating bodies are set so that the paper does not become slack due to the rotation of the paper feed roller 6 and the spool shaft 1 during rewinding even when the remaining amount of the roll paper Pr is small. . Therefore, while the remaining amount of the roll paper Pr is large and the outer diameter is large, the rotation of the spool shaft 1 causes the paper to be rewound longer than the amount of paper rewound corresponding to the amount of rotation of the paper feed roller 6. However, this difference in rotation is offset by slipping of a load generating mechanism such as a torque limiter, for example, and the sheet is rewound while maintaining a constant tension without causing slack in the sheet.

<Configuration of roll driving device>
Next, the driving device 7 of the roll paper feeding device 20 according to the present embodiment will be described with reference to FIGS. FIG. 5 is a diagram schematically illustrating the configuration of the driving device 7 of the roll paper feeding device 20 according to the present embodiment.

  The drive device 7 according to the present embodiment includes a drive motor 31, a progressive feed mechanism 32, a roll paper drive mechanism 33, a regeneration mechanism 34, and a rewind mechanism 35. Here, as the forward feed mechanism 32, a first gear; a pulley 41, a second gear 42, a third gear 43, a fourth gear 44, and a fifth gear 45 are mounted. As the regenerative mechanism 34, a first clutch built-in pulley 51 is mounted. A second clutch built-in pulley 52 is mounted as the rewind mechanism 35.

  As the roll paper drive mechanism 33, a sixth gear 46, a seventh gear 47, an eighth gear 48, a ninth gear 49, and a torque limiter 36 are mounted. Here, in the roll paper drive mechanism 33, the sixth gear 46, the seventh gear 47, the eighth gear 48, and the ninth gear 49 function as the drive transmission unit 53 that transmits the driving force to the spool shaft 1. The torque limiter 36 functions as a load generating unit.

  The drive motor 31 generates a predetermined driving force for transporting the paper P from the roll paper Pr in both forward and reverse directions. The drive motor 31 can transport the paper P in both forward and reverse directions.

  The forward feed mechanism 32 transmits a driving force for transporting the paper P from the roll paper Pr in the forward feed direction to the paper P transported from the roll paper Pr in the forward feed direction through the paper feed roller 6 during the forward feed operation. To do.

  The roll paper drive mechanism 33 transfers the forward driving force for unwinding (carrying out) the paper P from the roll paper Pr. Further, the roll paper drive mechanism 33 is given a driving force in the forward feed direction by the paper P conveyed in the forward feed direction from the roll paper Pr during the forward feed operation. Further, the roll paper drive mechanism 33 transmits a driving force for rewinding the paper P to the roll paper Pr during the rewinding operation from the drive motor 31 to the roll paper Pr via the spool shaft 1 and the flange 4.

  The torque limiter 36 is an example of a load generator that generates a rotational load in the present invention. The torque limiter 36 prevents the paper P from the roll paper Pr from being excessively conveyed by inertia when the paper supply roller 6 intermittently conveys the paper P from the roll paper Pr in the forward direction, and prevents the paper from becoming slack. Therefore, a tensile force (back tension) is applied in the rewind direction of the paper.

  In the regenerative mechanism 34, the roll paper driving mechanism 33 to which the driving force in the forward feeding direction is applied by the paper P conveyed in the forward feeding direction from the roll paper Pr during the forward feeding operation is supplied to the progressive feeding mechanism 32. Then, the driving force is regenerated to the driving motor 31.

  The rewinding mechanism 35 transmits a driving force for rewinding the paper P onto the roll paper Pr during the rewinding operation from the drive motor 31 to the roll paper Pr via the roll paper driving mechanism 33 and the spool shaft 1. In other words, the rewinding mechanism 35 conveys the paper P through the roll paper driving mechanism 33 in the opposite direction to the forward feeding direction, and rewinds the paper onto the roll paper Pr.

  FIG. 6 is a block diagram of the roll paper feeding device 20 according to the present embodiment. In FIG. 6, the control unit 100 includes a CPU 101, a bus 102, a ROM 103, a RAM 104, an I / O unit 105, a roll paper state determination unit 106, motor drive control units 107 and 108, and a load detection unit 109. It is comprised so that.

  A CPU (Central Processing Unit) 101 controls the entire apparatus using various data stored in a ROM (Read Only Memory) 103. For example, the CPU 101 instructs execution of the intermittent conveyance operation of the present embodiment and execution of a post-roll end sequence described later.

  A ROM (an example of a storage unit) 103 holds a program corresponding to a processing procedure executed by the CPU 101 and various types of information. For example, in the present embodiment, the ROM 103 stores various information acquired from the rotary encoder 16, the load detection unit 109, and the paper leading edge detection sensor 77 via the I / O unit 105.

  A RAM (Random Access Memory) 104 is used as a work area for arithmetic processing by the CPU 101.

  The I / O unit 105 includes, for example, an input / output port, and performs input and various control outputs of the rotary encoder 16, the load detection unit 109, the paper leading edge detection sensor 77, or other sensors. For example, in this embodiment, the I / O unit 105 includes position information such as the angle of the registration roller 10 from the rotary encoder 16, load information of the drive motor 31 from the load detection unit 109, and an image from the sheet leading edge detection sensor 77. Information such as a signal for detecting the leading edge of the paper P conveyed in the forming unit 60 is acquired.

  The motor drive control means 107, 108 are driven to the registration motor 13 that rotates the registration roller 10, the paper feed roller 6, and the drive motor 31 that rotates the spool shaft 1 based on the control signal transmitted by the I / O unit 105. Control by outputting a signal.

  The drive motor (drive means, drive source) 31 is controlled by the motor drive control means (drive means control unit) 108 to generate a predetermined drive force and transmit the drive force to the progressive feed mechanism 32. The progressive feed mechanism 32 rotates the paper feed roller 6. Further, the progressive feed mechanism 32 transmits the driving force, thereby driving either the regenerative mechanism 34 or the rewinding mechanism 35, and rotationally driving the spool shaft 1 via the drive mechanism 33.

  Motor drive control means 107 and 108 generate drive signals, which are signals used for variable speed, for the registration motor 13 and the drive motor 31, respectively. As the drive signal, a voltage signal or current signal of a PWM signal or a clock signal is used. These generated signals (PWM signals) are output from the motor drive control means 107 and 108 to the registration motor 13 and the drive motor 31.

  In response to the drive signal, the registration motor 13 rotates the registration roller 10 and the drive motor 31 rotates the spool shaft 1 and the paper feed roller 6 to convey the paper P.

  Here, the rotation of the registration roller 10 driven by the registration motor 13 is detected by detecting position information such as an angle by the rotary encoder 16 shown in FIG.

  Further, a load detection means (signal detection means) 109 comprising a voltage detection unit or a current detection unit detects a load applied to the drive motor 31 (continuously) by detecting a drive signal (PWM signal). .

  The paper leading edge detection sensor 77 detects the leading edge of the paper P being conveyed in the image forming unit 60.

  The roll paper state determination means 106 is based on the current load calculated based on the value of the drive signal to the drive motor 31 detected by the load detection means 109 and the value of the drive signal detected immediately before being stored in the ROM 103. The state of the roll paper Pr is determined by comparing with the calculated load value. Details of the roll paper Pr state determination method (roll end detection method) will be described later with reference to FIGS.

  FIG. 7 is a perspective view showing an example of the regenerative mechanism 34 and the rewinding mechanism 35 of the driving device 7 of the roll paper feeding device 20 according to the present embodiment, excluding the mounting support bracket and the like.

  In the example shown in FIG. 7, the first gear; pulley 41 of the forward feed mechanism 32 includes a first pulley 41 a, a tenth gear 41 b, an eleventh gear 41 c, and a twelfth gear 41 d. The first pulley 41 a is provided on a different shaft from the drive motor 31, and is provided so as to transmit a drive force to and from the drive motor 31. The tenth gear 41 b is provided coaxially with the first pulley 41 a and the second gear 42. The eleventh gear 41c is provided on a different shaft from the tenth gear 41b, and transmits a driving force to the tenth gear 41b. The twelfth gear 41d is provided coaxially with the eleventh gear 41c.

  FIG. 7 is an enlarged perspective view showing the periphery of the regeneration mechanism 34 and the rewinding mechanism 35 in FIG. FIG. 8 is an enlarged view showing the periphery of the first and second one-way clutches and the torque limiter 36 in the region surrounded by the dotted line I in FIG.

  In the regeneration mechanism 34, the first one-way clutch 51a is locked when the first pulley 51 with a built-in clutch rotates in the rewind direction relative to the input shaft 38 of the torque limiter 36, and the first clutch with a built-in first clutch. The pulley 51 is provided so as to idle when it rotates in the forward feed direction relative to the input shaft 38 of the torque limiter 36.

  Further, in the rewinding mechanism 35, the second clutch built-in pulley 52 also includes the second one-way clutch 52a and is locked to the input shaft 38 of the torque limiter 36 via the second one-way clutch 52a. It can be idle or switched.

  The second one-way clutch 52a is locked when the second pulley 52 with a built-in clutch rotates in the rewinding direction relative to the input shaft 38 of the torque limiter 36, and the pulley 52 with a built-in clutch 52 has a torque limiter. It is provided so as to idle when rotating in the forward feed direction relative to the 36 input shafts 38.

  In the forward feed operation, as indicated by the white arrow in FIG. 8, a driving force that rotates in the forward feed direction is applied to the paper feed roller 6 so as to transport the paper P from the roll paper Pr in the forward direction. At this time, since the second one-way clutch 52a built in the second clutch built-in pulley 52 as the rewinding mechanism 35 is idled, the rewinding mechanism is between the roll paper drive mechanism 33 and the progressive feed mechanism 32. No driving force is transmitted via 35. Accordingly, the rewinding driving force is not transmitted from the drive motor 31 to the spool shaft 1 via the rewinding mechanism 35.

  On the other hand, in the regenerative mechanism 34, the first one-way clutch 51a built in the first clutch built-in pulley 51 is locked, so that the regenerative mechanism 34 is interposed between the roll paper drive mechanism 33 and the progressive feed mechanism 32. The driving force is transmitted. Therefore, a part of the driving force transmitted to the roll paper drive mechanism 33 by the paper P conveyed from the roll paper Pr is regenerated to the progressive feed mechanism 32 via the first one-way clutch 51a and the first clutch built-in pulley 51. Thus, the driving force can be regenerated to the drive motor 31.

  Along with the regenerative operation, the torque limiter 36 also serves to absorb the force when the driving force applied by the paper conveyed from the roll paper Pr is overloaded. Therefore, the braking force cancels out the force that the paper P from the roll paper Pr moves forward in the forward direction due to inertia when stopping during intermittent conveyance.

  Here, the first clutch built-in pulley (low rotation pulley, regenerative mechanism 34) 51 incorporating the first one-way clutch 51a is torque that is rotationally driven by the paper P conveyed from the roll paper Pr. The reduction ratio is such that it always rotates at a rotational speed lower than the rotational speed of the output shaft 37 of the limiter 36. With this setting, when the paper is conveyed from the roll paper Pr in the forward feed direction, the rotational speed of the output shaft 37 of the torque limiter 36 that is the first load generating mechanism is rotationally driven by the drive motor 31 that is the driving means. The first one-way clutch 51a and the second one-way clutch 52a can be switched when the rotational speed R1 of the first clutch built-in pulley (or gear, regenerative mechanism 34) 51 is higher. A regenerative operation is performed by this operation.

  By such a regenerative operation, for example, power necessary for stopping the intermittent conveyance operation, for example, power for stopping the rotating roll paper Pr, an operation of rewinding the extra length conveyed by the inertia of the roll paper Pr itself. It is possible to regenerate electric power and the like for braking the driving of the roll paper Pr so as not to be excessively conveyed due to electric power and inertia. Also, starting against the load (torque) for rotating the heavy roll paper Pr to drive each motor that rotates each roller that transports the roll paper Pr, which is generated when the intermittent transport operation is started. In order to achieve this, the regenerated driving force can be used.

  In the rewinding operation, as indicated by the black arrow in FIG. 8, the paper feeding roller 6 is given a driving force that rotates in the rewinding direction to transport the roll paper Pr in the direction opposite to the forward direction. At this time, since the first one-way clutch 51a built in the first clutch built-in pulley 51 (low rotation pulley) as the regenerative mechanism 34 is idling, the roll paper drive mechanism 33 and the progressive feed mechanism 32 are not connected. The driving force is not transmitted through the regeneration mechanism 34. Therefore, the driving force is not transmitted from the drive motor 31 to the spool shaft 1 via the regeneration mechanism 34.

  On the other hand, since the second one-way clutch 52a built in the second clutch built-in pulley 52 (high rotation pulley) is locked, the rewinding mechanism 35 is moved between the progressive feed mechanism 32 and the roll paper drive mechanism 33. The driving force is transmitted via Therefore, the spool shaft 1 is rotated in the rewinding direction via the second clutch built-in pulley 52 (high rotation pulley) and the torque limiter 36 that are rotationally driven by the progressive feed mechanism 32.

  At this time, the first clutch built-in pulley (low-speed) during the rewinding operation is in any range where the rotational speed (the absolute value thereof) of the output shaft 37 of the torque limiter 36 changes the diameter of the roll paper Pr. The rotation speed is set in advance so as to be equal to or higher than the rotation speed (absolute value) of the rotation pulley 51. Accordingly, the rewinding operation enables winding without causing slack between the paper feed roller and the roll paper.

  The detailed configuration, operation, and advantages of the regeneration mechanism are disclosed in, for example, Japanese Patent Application Laid-Open No. 2011-005721.

  With this arrangement, in the present embodiment, the drive motor 31 can perform either the forward feed operation or the rewind operation via the roll paper drive mechanism 33. The rewinding mechanism 35 and the regenerative mechanism 34 are provided so as to be switchable depending on the rotation direction of the drive motor 31. When the drive motor 31 rotates in the forward feed direction, the regenerative mechanism 34 and the drive motor 31 move in the rewind direction. When rotating, the rewinding mechanism 35 functions.

<Control>
Here, the control in the embodiment of the present invention will be described. FIG. 9A is a graph showing the linear velocity of the flange 4 and the linear velocity of the paper feed roller 6 when the roll paper Pr in which the rear end of the paper P is bonded to the core tube Ps becomes the roll end. FIG. 9B is a graph showing the voltage (applied drive signal) of the drive motor 31 when the roll paper Pr in which the rear end of the paper P is bonded to the core tube Ps becomes the roll end.

  Referring to FIGS. 9A and 9B, in this case, at the roll end Te, in order to generate a predetermined driving force that drives the paper feed roller 6 at a predetermined linear velocity, the drive motor 31 is used. It can be seen that the electric power applied to increases (continues to increase for a predetermined period). This is because regeneration by the regeneration mechanism 34 is eliminated.

  FIG. 10A is a graph showing the linear velocity of the flange 4 and the linear velocity of the paper feed roller when the roll paper Pr whose rear end is not bonded to the core tube Ps becomes the roll end. FIG. 10B is a graph showing the voltage of the drive motor 31 when the roll paper Pr in which the rear end of the paper P is bonded to the core tube Ps becomes the roll end.

  Referring to FIG. 10A and FIG. 10B, in this case, at the roll end Te, in order to generate a predetermined driving force that drives the paper feed roller 6 at a predetermined linear velocity, the drive motor 31 is generated. It can be seen that the power applied to the power supply decreases (continues to decrease for a predetermined period). This is because the back tension to the paper P that has been a load on the drive motor 31 is eliminated by peeling the rear end of the paper P from the core tube Ps.

  As described above, in the roll paper feeding device 20, the rear end of the paper P is bonded to the core tube Ps by detecting the presence or absence of regeneration to the drive motor 31, that is, the increase or decrease of the voltage applied to the drive motor 31. Regardless of whether or not there is a roll end, it is possible to detect the roll end accurately and without increasing the configuration.

  FIG. 11 is a flowchart of transport control according to the embodiment of the present invention.

  Here, as a premise, the roll paper Pr has the paper P wound around the core tube Ps in a roll shape, and its leading end is pulled out to become the paper P to be recorded. The end of the paper P is wound around the core tube Ps, but the end is fixed to the core tube Ps by an adhesive or the like, or the paper P is simply wound around the core tube Ps without being fixed. is there. Further, even if the end of the roll-shaped paper P is fixed to the core tube Ps, the degree of the fixing is various, and there are some which are difficult to peel off and those which are easy to peel off. Further, in this embodiment, the roll paper (roll-like recording member) P is wound around the core tube Ps, but the core tube Ps is not provided, and it may be simply rounded. In the present invention, the core portion means both a portion wound around the core tube Ps and a portion that is round without the core tube Ps.

  When starting is started, the drive motor (drive means) 31 is turned ON in step S1. At this time, the driving means 31 is controlled so as to have a predetermined output value.

  In S2, the load detection sensor 109 starts continuous detection of the load (current or voltage) of the drive motor 31 for each intermittent drive. Simultaneously with the start of detection, the ROM 103 serving as storage means continuously stores the detected load value.

  Then, the CPU 101 compares the previous load value (the stored load value detected immediately before) with the load value detected this time (S3).

  If the load does not change (S4, NO), the load value detection and storage are repeated (S6, NO) until the drive motor 31 stops due to the end of paper feeding.

  When the load value detected this time has changed from the previous load value (S4, YES), as shown in FIG. 9B, the load value detected this time is detected immediately before and increases from the load value. If YES (S5, YES), the roll paper state determination means 106 determines that the roll end is in a state where the rear end of the paper P is attached to the core tube Ps (S7).

  On the other hand, as shown in FIG. 10B, when the load value detected this time has decreased from the load value detected immediately before (S5, NO), the roll paper state determination means 106 eliminates regeneration by the regeneration mechanism 34. The roll end is determined as a state where the rear end of the paper P (roll end) is not attached to the core tube Ps.

  If it is determined that the roll end is in a state where the rear end of the paper P is adhered to the core tube Ps (S7), the sequence after the adhesive roll end is performed (S8), and the operation is terminated. The adhesive roll end sequence will be described later with reference to FIG.

  If it is determined that the roll end is not attached to the core tube Ps (S9) (S9), the sequence after the free end roll end is performed (S10), and the operation is terminated.

  The detailed case classification after the roll end state is determined is disclosed in, for example, Japanese Patent Application Laid-Open No. 2014-108589.

  FIG. 12 shows a detailed flowchart in the post-adhesion roll end sequence.

  In step S <b> 801, the CPU 101 applies a tensile force to the paper P while preventing heat generation, peels the roll end of the paper P from the core tube Ps, and discharges it from the transport path 9. The motor drive control means 108 is controlled so as to drive the drive motor 31 in the forward rotation direction for a predetermined time.

  Also at this time, the load detection sensor 109 continuously detects the load value of the drive motor 31 (current value or voltage value of the applied drive signal). (S802).

  If the detected load value becomes smaller than the predetermined value before the application of the limited low power voltage reaches the predetermined period (S817) (YES in S803), the rear end of the sheet P is peeled off from the core tube Ps. Judgment (determining that the roll end is half-end paper) (S804).

  If it is determined in step S804 that the trailing edge of the sheet P has been peeled off from the core tube Ps, the length of the roll end is calculated based on the stored load decrease time and the motor rotation amount, and the calculated roll end length is calculated. Then, the distance is compared with the distance of the image information used for image formation (S805).

  When the length of the roll end is longer than the distance of the image information used for image formation (YES in S806), the drive motor 31 is intermittently driven so as to continue image formation (S807).

  After the image formation is completed (S808), the drive motor 31 is continuously driven to convey the paper P in the same forward conveyance direction as that during image formation, and the roll end is discharged from the conveyance path 9 (S809). After the roll end, the drive motor 31 is stopped (S810), and then the roll paper Pr is replaced (S811).

  On the other hand, if the length of the roll end is shorter than the distance required for the current image formation in S806, the drive motor 31 is continuously driven for a predetermined time, and the roll end is discharged from the conveyance path 9 (S812). After driving for a predetermined time for discharging, the drive motor 31 stops (S813). Then, the roll paper Pr is replaced (S814).

  Thereafter, the intermittent drive of the drive motor 31 is resumed for image formation (S815). Then, with the completion of the image forming operation, the drive of the drive motor 31 is stopped (S816).

  On the other hand, when the voltage is continuously applied to the drive motor 31 with the limited low power and the load value remains larger than the predetermined value and a predetermined period has elapsed (NO in S803, YES in S817), the roll paper state determination unit 106 Then, it is determined that the rear end of the paper P is fixed to the core tube Ps (S818).

  In this case, the drive motor 31 is rotated in the reverse direction, the roll end is conveyed in the opposite conveyance direction to that at the time of image formation, and the roll end fed into the conveyance path 9 is wound around the core tube Ps (S819). Thereby, the paper P (roll end) in the transport path 9 is collected to the core tube Ps side. After rotating for a predetermined time calculated by the control unit 100, the drive motor 31 stops (S820). Then, the roll paper Pr is replaced (S814).

  Thereafter, in the same manner as described above, the intermittent drive of the drive motor 31 is resumed for image formation (S815), and the drive of the drive motor 31 is stopped when the image formation operation ends (S816).

  In addition, when progressing to a sequence after a free end roll end in S10 in FIG. 11, the process of step S805-S816 in FIG. 12 is implemented.

  11 and 12, when the roll paper feeding device 20 detects that the paper P is at the roll end (near) by the load detecting means 109, the roll paper feeding device 20 responds to the winding state of the roll end around the core tube Ps. Thus, the conveyance direction of the paper P is determined, and the roll end portion is discharged or rewound from the conveyance path 9. As a result, the roll end (terminal portion) portion of the roll paper P can be removed from the transport path 9, and the work of removing the roll end portion by manual operation can be omitted, thereby improving the usability.

  As described above, in the roll paper supply device 20 according to the embodiment of the present invention, since the load detection unit 109 is installed inside the control unit 100, a new detection unit is not provided in the conveyance path 9, and the cost can be reduced. It becomes possible to detect the roll end without adding a new mechanism.

  Furthermore, in the embodiment of the present invention, the load detection means 109 can detect the load state at any time by detecting the drive signal to the drive motor 31, so that the roll end can be detected accurately and promptly. .

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to such specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Can be modified or changed.

  Further, as described above, the image forming apparatus 80 according to the present invention is an ink jet printer as long as it is an image forming apparatus that forms an image by feeding a roll type sheet medium such as roll paper from a roll paper feeding device. The present invention is not limited, and includes various image forming apparatuses such as a printer, a plotter, a fax machine, and a copier equipped with a roll paper feeding device. That is, the roll paper feeding device in the present invention can be applied to various image forming apparatuses such as a printer, a plotter, a fax machine, and a copying machine.

1 Spool shaft 2 Relay roller (upper support roller)
3 Relay roller (lower support roller)
4 Flange 5 Spool bearing base 6a, 6b Paper feed roller 7 Driving device 8a, 8b Roll paper base 9 Transport path 10 Registration roller 11 Timing pulley 12 Timing belt 13 Registration motor 16 Rotary encoder 17 Registration pressure roller 20 Roll paper feeding Device 60 Image forming unit 31 Drive means (drive motor, DC motor)
32 Forward feed mechanism 33 Roll paper drive mechanism 34 Regenerative mechanism 35 Rewind mechanism 36 Torque limiter (load generation unit)
53 Drive transmission unit 80 Image forming apparatus 100 Control unit 101 CPU
106 Roll paper state determination means 107 Motor drive control section 108 Motor drive control section (drive means control section)
109 Load detection means P Paper (roll paper being conveyed)
Pr Roll paper Ps Core tube

JP 2000-109256 A JP-A-7-253695 JP 2011-005721 A

Claims (9)

There is a roll paper supply device capable of feeding paper from roll paper to an image forming unit that forms an image on paper,
A rotatable driving means for generating a driving force for conveying the paper;
A forward feed mechanism that transmits a driving force from the driving unit and transmits a driving force for feeding the paper from the roll paper from the driving unit;
A rotational load is generated by the drive transmission unit that transmits the driving force to the roll paper and the paper transported in the forward feed direction, and the transport load is applied to the paper transported from the roll paper in the forward feed direction by the rotational load. A roll paper drive mechanism including a load generating unit;
A rewinding mechanism for transporting the paper in a direction opposite to the forward feed direction and rewinding the paper on the roll paper;
The driving force existing in the roll paper driving mechanism, to which the driving force in the forward feeding direction is applied by the paper conveyed in the forward feeding direction from the roll paper, is transmitted back to the progressive feeding mechanism to regenerate the driving force to the driving means. A regenerative mechanism to
The rewinding mechanism and the regenerative mechanism are provided so as to be switchable depending on the rotation direction of the driving means,
When the drive means rotates in the forward feed direction, the regeneration mechanism functions, and when the drive means rotates in the rewind direction, the rewind mechanism functions,
A roll paper feeding device characterized in that the presence or absence of a regeneration effect during conveyance is detected by a load fluctuation of the driving means. The roll paper feeding device further includes a control unit that controls the driving unit,
The controller is
A driving means controller for controlling the driving means to generate a predetermined driving force by applying a driving signal, and continuously detecting a driving signal applied to the driving means that changes depending on a load on the driving means. The roll paper feeding device according to claim 1, further comprising a load detection unit configured to detect a load fluctuation of the driving unit by continuing the operation. The control unit includes storage means for storing the value of the drive signal,
The roll paper feeding device according to claim 2, wherein the load fluctuation is calculated by comparing the drive signal detected this time with the drive signal detected immediately before. When the load of the drive means calculated based on the drive signal detected this time is increased from the load of the drive means calculated based on the drive signal detected immediately before, The roll paper feeding device according to claim 3, wherein the roll paper is determined to be a roll end in a state where a rear end of the paper is bonded. When the load of the drive means calculated based on the drive signal detected this time is reduced from the load of the drive means calculated based on the drive signal detected immediately before, The roll paper feeding device according to claim 3, wherein the roll paper is determined to be a roll end in which the rear end of the paper is not adhered. The control unit causes the transport unit to transport the sheet in a forward transport direction or a reverse transport direction opposite to the forward transport direction according to a determination result of the state of the roll end. Item 6. The roll paper feeding device according to any one of Items 4 and 5. The roll paper feeding device according to any one of claims 2 to 6, wherein the drive signal applied to the drive unit by the drive unit control unit is a PWM signal. An image forming unit that forms an image on the conveyed paper;
An image forming apparatus comprising: the roll paper feeding device according to claim 1. A roll end detection method for a roll paper feeding device, wherein the roll paper feeding device comprises a transport means for transporting a paper transported from the roll paper, and a rotatable drive for generating a driving force for transporting the paper. Means, a forward feed mechanism that transmits a driving force from the driving means, and a driving force for delivering the paper from the roll paper, a drive transmission unit that transmits the driving force to the roll paper, and the forward feed. A roll paper drive mechanism including a load generating unit that generates a rotational load by the paper transported in the direction and applies a transport load to the paper transported in the forward feed direction from the roll paper by the rotational load; and the paper in the forward feed direction A rewind mechanism that rewinds the paper onto the roll paper, and a forward feed direction by the paper fed from the roll paper in the forward feed direction. The driving forces present in the rolled paper driving mechanism driving force is imparted, and and a regeneration mechanism for regenerating the driving force to said driving means returns transmitted to the forward mechanism,
The roll end detection method is
Applying a driving signal to the driving means so as to generate a predetermined driving force by the driving means;
Continuously detecting a drive signal applied to the drive means that varies depending on a load on the drive means;
Storing the detected value of the drive signal;
By comparing the drive signal detected this time with the value of the drive signal detected immediately before, calculating the fluctuation of the load, and determining the presence or absence of a regenerative effect during conveyance;
Detecting whether the roll paper is a roll end based on a change in the load, and a roll end detection method.