JP2011143997A - Method of monitoring conveying state of recording paper of printer and printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect the defective conveyance of recording paper by paper feed rollers in a printer having a delivery mechanism by a simple configuration. <P>SOLUTION: In this paper roll printer 1, whether the tension of recording paper 8a reaches predetermined set tension or not is monitored based on an output of a sensor 24 for detecting a position of a tension guide 19 during the conveyance of the recording paper by a pair of the paper feed rollers 26 (ST4), and when the sensor 24 is turned on, a delivery operation for the recording paper is performed by a pair of delivery rollers 25. A feed amount of paper from the beginning of the conveyance of the recording paper 8a by the pair of paper feed rollers 26 is monitored by counting the quantity of drive steps of a paper feed motor 32 (ST3), and when the sensor 24 is not turned off even if the paper is fed by a predetermined amount, it is determined that the defective conveyance of paper by the pair of paper feed rollers 26 has occurred (ST4, ST7). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is directed to a tension guide that holds a recording paper in a predetermined tension state and the recording paper toward the paper feeding roller in order to suppress fluctuations in the paper feeding load that acts on the paper feeding roller that conveys the long recording paper. The present invention relates to a printer provided with a feeding roller. More specifically, the present invention relates to a recording paper conveyance state monitoring method for monitoring whether or not a defect has occurred in a recording paper conveyance operation by a paper feed roller in this type of printer.

  Patent Documents 1, 2, and 3 propose roll paper printers including a tension guide and a feeding roller. As disclosed in these patent documents, the tension guide is supported so as to be displaceable toward and away from the recording paper, and is pressed against the recording paper by a spring force. Displacement of the tension guide suppresses fluctuations in tension acting on the recording paper. Further, when it is detected that the tension guide is largely displaced by a sensor disposed in the vicinity of the tension guide, the recording paper is fed out by the feeding roller in order to relieve the large tension acting on the recording paper. Thereby, the tension fluctuation of the recording paper is effectively suppressed. That is, the fluctuation of the paper feeding load acting on the paper feeding roller is suppressed, and the paper feeding operation is performed with high accuracy. Further, in Patent Document 3, it is determined based on the sensor output whether or not a failure has occurred in the recording paper feeding operation by the feeding roller.

  Here, in a printer such as a roll paper printer that prints on a long recording paper, a stepping motor (pulse motor) is generally used as a rotational drive source of the paper feed roller. Since stepping motors are normally driven and controlled by open loop control, an encoder for detecting the motor rotation position is not provided. For this reason, the paper feed amount and the like are calculated by the number of driving steps of the stepping motor.

JP 2007-203563 A JP 2007-203564 A JP 2009-269399 A

  In printers equipped with a feeding mechanism that uses a tension guide and a feeding roller to suppress the load fluctuation of the recording paper, in addition to the recording paper feeding operation failure by the feeding roller, recording paper conveyance failure by the paper feeding roller may occur. There is. For example, due to tearing of the roll paper, wear of the paper feed roller, etc., the roll paper part may be perforated at the paper feed position by the paper feed roller, and paper feed by the paper feed roller may not be possible. . Also, the stepping motor used as the paper feed motor is out of step, the transmission mechanism that transmits the rotational force of the paper feed motor to the paper feed roller (for example, idling of the gears constituting the transmission mechanism, the drive belt coming off, etc.) ) May cause paper feeding to fail.

  In order to detect such a defective recording paper transport operation by the paper feed roller, it is desirable to monitor the rotation state of the paper feed roller or the rotation state of the stepping motor. For this purpose, it is necessary to newly install a detection mechanism for detecting these rotational states. However, adding such a detection mechanism is not preferable because it leads to an increase in the size and cost of the printer. In many cases, a small printer cannot secure a space for installing such a detection mechanism.

  SUMMARY OF THE INVENTION In view of these points, an object of the present invention is to provide a monitoring method of a recording paper conveyance state of a printer that can detect a conveyance failure of a recording paper by a paper feeding roller without adding a new detection mechanism, and , To propose a printer.

In order to solve the above-described problem, the recording paper conveyance state monitoring method of the printer of the present invention is:
The portion of the long recording paper located between the paper feeding position by the feeding roller and the paper feeding position by the paper feeding roller is bridged over a displaceable tension guide to which a predetermined urging force is applied,
Monitoring whether or not the tension generated in the recording paper reaches a predetermined set tension during the conveyance of the recording paper by the paper feed roller;
When the tension generated on the recording paper reaches the set tension during the conveyance of the recording paper by the paper feed roller, the recording paper is fed out by the feeding roller until the tension falls below the set tension. Done
Even when the conveyance amount of the recording paper from the predetermined time point of conveyance of the recording paper by the paper feed roller reaches a time point when the predetermined conveyance amount should be reached, the tension generated in the recording paper becomes the set tension. If not reached, it is determined that a defect has occurred in the recording paper transport operation by the paper feed roller.

  In the method of the present invention, the monitoring information used for controlling the feeding operation of the recording paper by the feeding roller, that is, the monitoring information as to whether or not the tension generated in the recording paper has reached the set tension is displayed by the paper feeding roller. This is used to determine whether or not a defect has occurred in the recording paper transport operation. That is, when the recording paper is normally conveyed by the paper feeding roller, the tension state of the recording paper spanned between the recording paper feeding roller and the feeding roller increases (in other words, the recording paper portion of the recording paper portion). The slack is removed), and the tension of the recording paper increases and exceeds the set tension. When the recording paper is not conveyed by the paper feed roller, the tension of the recording paper does not increase, and when the conveyance is insufficient, the tension does not reach the set tension. Therefore, at least during the recording paper transport operation by the paper feed roller, a new detection mechanism is established by using monitoring information on whether the tension of the recording paper used for the feed control by the feed roller reaches the set tension. Without mounting, it is possible to detect a conveyance failure by the paper feed roller. Further, even at the start time or stop time of the conveyance of the paper feed roller, the tension can be continuously monitored to determine a conveyance failure. Further, the transport amount of the recording paper may be calculated from a predetermined point in time of transport in addition to the case of calculating from the start of transport.

  Here, it is desirable to monitor whether the tension generated on the recording paper has reached the set tension based on the displacement amount of the tension guide. This is because the amount of displacement can be easily detected by a position detection sensor such as an optical sensor.

  Further, when the recording paper is transported by rotating the paper feed roller using a stepping motor driven by open loop control, the transport amount of the recording paper by the paper feed roller is the set transport amount. It is desirable to determine whether or not it is time to reach the value based on the number of driving steps of the stepping motor.

Next, the printer of the present invention is
A print head;
A paper feed roller that transports a long recording paper via a printing position by a print head, and
A feed roller for feeding the recording paper toward the paper feed roller;
The transfer portion of the recording paper that is stretched between the paper feed position by the feed roller and the paper feed position by the paper feed roller can be pressed with a predetermined biasing force, and is displaced against the biasing force. A tension guide that can
A sensor that detects whether or not the tension generated in the bridging portion of the recording paper has reached a predetermined set tension;
Control means for controlling the driving of the paper feed roller and the feed roller,
When the control means detects that the tension generated in the bridging portion of the recording paper reaches the set tension based on a detection signal of the sensor at least during conveyance of the recording paper, the tension is set to the setting tension. The recording paper is fed out by the feeding roller until the tension is less than the tension, and even if the recording paper transport amount by the paper feed roller reaches a preset transport amount, the recording paper is generated. When the tension does not reach the set tension, it is determined that a defect has occurred in the recording paper transport operation by the paper feed roller.

  Here, as the sensor, a sensor that detects whether or not the tension guide is displaced by a predetermined displacement amount can be used.

  Further, in the case of having a stepping motor that rotationally drives the paper feed roller, the control means determines when the transport amount of the recording paper by the paper feed roller should reach the set transport amount. What is necessary is just to detect based on the drive step number of a stepping motor.

  In the present invention, the monitoring information on whether or not the tension of the recording paper used for controlling the feeding operation of the recording paper by the feeding roller has reached the set tension is used to determine the conveyance failure of the recording paper by the paper feeding roller. We are using. Therefore, the conveyance failure of the recording paper by the paper feed roller can be easily detected without adding a new detection mechanism or the like, and the cost and size of the printer are not increased.

1 is an external perspective view of a roll paper printer to which the present invention is applied. FIG. 2 is a schematic configuration diagram and a partial explanatory diagram illustrating an internal structure of the roll paper printer. It is a schematic block diagram which shows the control system of a roll paper printer. It is a schematic flowchart which shows the monitoring operation | movement of a recording paper conveyance state. It is a schematic flowchart which shows the delivery operation | movement by a delivery roller pair. 6 is a timing chart of a recording paper conveyance operation and a feeding operation.

  Hereinafter, an embodiment of a printer to which a recording paper conveyance state monitoring method according to the present invention is applied will be described with reference to the drawings.

(overall structure)
FIG. 1A is an external perspective view of an ink jet type roll paper printer according to an embodiment of the present invention, and FIG. 1B is an external perspective view of a state in which the opening / closing lid is fully opened. As shown in these drawings, the roll paper printer 1 has a printer body 2 having a substantially rectangular parallelepiped shape as a whole, and an opening / closing lid 3 attached to the front surface of the printer body 2. The open / close lid 3 includes a lid frame 3a and a lid cover 3b attached thereto. A recording paper discharge port 4 having a predetermined width is formed on the front surface of the outer case 2 a of the printer body 2. A paper discharge guide 5 protrudes forward below the recording paper discharge port 4, and a lid opening / closing lever 6 is disposed on the side of the paper discharge guide 5. A rectangular opening 2b for inserting and removing roll paper is formed below the paper discharge guide 5 and the lid opening / closing lever 6 in the outer case 2a. The opening 2b is sealed by the opening / closing lid 3.

  When the lid opening / closing lever 6 is operated, the lock (not shown) of the opening / closing lid 3 is released. When the paper discharge guide 5 is pulled forward, the opening / closing lid 3 is opened from the closed position 3A in the standing state shown in FIG. 1 (a) to the front shown in FIG. Open to position 3B. When the opening / closing lid 3 is opened, the roll paper storage unit 7 formed inside the printer body 2 is opened. At the same time, the platen unit 12 including the platen 18 for defining the printing position moves together with the opening / closing lid 3. As a result, the recording paper transport path from the roll paper storage unit 7 to the recording paper discharge port 4 is opened, and the roll paper can be easily replaced from the front of the printer. In FIG. 1B, the lid cover 3b and the lid opening / closing lever 6 are omitted.

(Internal configuration of printer)
2A is a schematic cross-sectional view showing an internal configuration of the roll paper printer 1, and FIG. 2B is a partial cross-sectional view thereof. Referring to these drawings, the roll paper printer 1 includes a sheet metal printer main body frame 11 on which various components are mounted. A lid frame 3 a is attached to the front end portion of the printer main body frame 11. A platen unit 12 is attached to an upper end portion of the lid frame 3a so as to extend rearward of the printer, and a lower side of the platen unit 12 is a roll paper storage unit 7. The platen unit 12 can be opened / closed together with the opening / closing lid 3 in a state in which the posture is maintained by a four-joint parallel link mechanism configured using the platen unit 12 and the lid frame 3a.

  An ink jet head 13 is disposed above the platen unit 12. The inkjet head 13 is mounted on a head carriage 14, and the head carriage 14 is guided in the printer width direction by a carriage guide shaft 15. The head carriage 14 can be reciprocated along the carriage guide shaft 15 by a carriage conveyance mechanism including a carriage motor 16 and a timing belt 17.

  The platen 18 mounted on the platen unit 12 is opposed to the nozzle surface of the inkjet head 13 with a certain gap from below, and the printing position by the inkjet head 13 is defined by the platen 18. A tension guide 19 having a curved guide surface is attached to the rear end portion of the platen unit 12 below the printer.

  As shown in FIG. 2 (b), the tension guide 19 can pivot up and down from the position indicated by the solid line to the position indicated by the imaginary line around the support shaft 20, and is a spring by a spring member (not shown). It is always biased upward (in the direction of arrow 21) by the force. A guide stopper (not shown) is formed on the platen unit 12, and the tension guide 19 urged upward by a spring force is held at a solid line position shown by the guide stopper and is moved downward against the spring force. It can be pushed down (displaced) in the direction of arrow 22.

  The recording paper 8a drawn out from the roll paper 8 stored in the roll paper storage unit 7 is drawn out rearward and upward of the printer, changed direction toward the front of the printer via the tension guide 19, and passed through the printing position. Then, it is arranged along the recording paper transport path 23 to the recording paper discharge port 4. In FIG. 2B, the recording paper transport path 23 is indicated by a one-dot chain line indicating the recording paper 8a. A predetermined tension is applied to the recording paper 8a by the tension guide 19, and the recording paper 8a is held in a tension state without slack. In the vicinity of the tension guide 19, a sensor 24 that detects that the tension guide 19 has moved (displaced) by a predetermined amount downward is disposed. The sensor 24 is, for example, a contact type sensor such as a mechanical switch, but may be a non-contact type sensor such as an optical sensor.

  In order from the upstream side of the recording paper conveyance path 23, a pair of feeding rollers 25 including a feeding roller 25a and a driven roller 25b, a pair of paper feeding rollers 26 including a paper feeding roller 26a and a driven roller 26b, and a conveying roller 27a and A conveying roller pair 27 including a driven roller 27b is disposed. The tension guide 19 is positioned between the feeding roller pair 25 and the paper feed roller pair 26, and the printing position of the inkjet head 13 is between the paper feed roller pair 26 and the transport roller pair 27.

  The feeding roller pair 25 is supported by the printer body frame 11 in a state extending in the printer width direction at a position below the tension guide 19. A rotational force is transmitted from the feeding motor 29 to the feeding roller 25a through the reduction gear train 28. The driven roller 25 b is supported in a freely rotatable state at the tip end portion (end portion on the rear side of the printer) of the roller support lever 30 attached to the platen unit 12. In a state where the open / close lid 3 is closed, it is pressed against the feeding roller 25a through the recording paper 8a by the spring force of the buffer spring 31.

  The paper feed roller 26 a of the paper feed roller pair 26 is mounted on the platen unit 12, and the driven roller 26 b is attached to the printer main body frame 11 side. When the open / close lid 3 is closed, a rotational force is transmitted to the paper feed roller 26 a from the paper feed motor 32 mounted on the printer main body frame 11 via the reduction gear train 33. Further, the driven roller 26b is pressed against the paper feed roller 26a through the recording paper 8a with a predetermined pressing force.

  The transport roller 27 a of the transport roller pair 27 is mounted on the platen unit 12, and the driven roller 27 b is attached to the printer main body frame 11 side. The transport roller 27a is connected to the paper feed roller 26a via a gear train (not shown) mounted on the platen unit 12, and rotates in synchronization with the paper feed roller 26a. In the state where the open / close lid 3 is closed, the driven roller 27b is pressed against the transport roller 27a with the recording paper 8a interposed therebetween.

  The recording paper 8 a drawn out from the roll paper 8 passes through the surface of the platen 18 via the feeding position (nip portion) of the feeding roller pair 25, the tension guide 19, and the feeding position (nip portion) of the paper feeding roller pair 26, The paper is drawn along a recording paper transport path 23 that reaches the recording paper discharge port 4 via the transport roller pair 27. The portion of the recording paper 8a that is stretched between the feed roller pair 25 and the paper feed roller pair 26 is stretched over a tension guide 19, and is biased upward by the tension guide 19 to give a predetermined tension. It has become a state.

  Printing is performed by the inkjet head 13 on the surface of the recording paper 8 a that is transported through the printing position on the platen 18 via the paper feed roller pair 26. After a series of line printing in the width direction of the recording paper 8a is completed, the paper feed roller pair 26 is rotationally driven to feed the recording paper 8a by a predetermined pitch for one line, and the next line printing is performed. The recording paper 8a is printed on the recording paper 8a by the inkjet head 13 while being intermittently sent out at a predetermined pitch. A recording paper cutting device, for example, a scissors type recording paper cutting device (not shown) is arranged at the recording paper discharge port 4 from which the recording paper 8a after printing is discharged. The recording paper 8a positioned therebetween is cut in the width direction by the recording paper cutting device.

(Control system)
FIG. 3 is a schematic block diagram showing a control system of the roll paper printer 1. The control system is mainly configured by a drive control unit 40 having a microcomputer. The drive control unit 40 receives print data supplied from a host device 41 such as a host computer, and performs a paper feeding operation and printing. Perform the action. Detection signals from various sensors (not shown) such as detection signals indicating the carriage position are input to the drive control unit 40. Based on these detection signals, the drive control unit 40 performs the feeding motor 29, the paper feed motor 32, and the carriage motor. 16 is driven and controlled via motor drivers 42, 43 and 44, and the inkjet head 13 is driven and controlled via a head driver 45. Stepping motors are used for the feeding motor 29 and the paper feed motor 32, but other types of motors may be used.

  The drive control unit 40 detects a signal 24S (the tension state of the recording paper 8a) from the sensor 24 that detects the movement position of the tension guide 19, the on / off of the paper feed motor 32 (start and stop of the paper feed operation), and the paper Based on the rotation speed of the feed motor 32 (recording paper feed speed by the paper feed roller 26a) and the number of drive steps of the paper feed motor 32 (paper feed amount), the drive of the feed motor 29 is controlled, and recording by the feed roller 25a is performed. Controls paper feeding and pulling operations.

  The storage area 46 of the drive control unit 40 stores and holds various parameters necessary for drive control of each unit. For example, the set paper feed amount used for detecting a paper feed operation failure by the paper feed roller pair 26 is stored and held as the number of drive steps of the paper feed motor 32 corresponding to the set paper feed amount. Drive control is performed based on these parameters.

(Recording paper conveyance status monitoring operation)
FIG. 4 is a schematic flowchart showing the recording paper conveyance state monitoring operation in the roll paper printer 1, and FIG. 5 is a schematic flowchart showing the recording paper feeding operation by the feeding roller pair 25 driven by the feeding motor. Is a timing chart thereof.

  First, a paper feeding operation by the paper feeding roller pair 26 will be described with reference to FIGS. The recording paper 8 a is pulled out in a state where the portion of the long recording paper 8 a located between the feeding position by the feeding roller pair 25 and the paper feeding position by the paper feeding roller pair 26 is stretched over the tension guide 19. Yes. In this state, a predetermined tension is applied to the recording paper 8 a supplied to the paper feeding roller pair 26 by the tension guide 19.

  For example, assume that the top of the recording paper 8a is located at the printing position of the inkjet head 13, and in this state, when print data is received from the host device 41 and a printing operation is started (step ST1 in FIG. 4), The recording paper 8a is fed to the printing start position at the top of the recording paper 8a. First, the paper feed motor 32 is driven, and the paper feed roller pair 26 and the transport roller pair 27 start transporting the recording paper 8a in the forward feed direction (step ST2 in FIG. 4, time t1 in FIG. 6). Since the recording paper 8a is pulled out by the paper feed roller pair 26, the tension of the recording paper 8a increases, and the tension guide 19 is pushed downward as the tension increases.

  When the tension of the recording paper 8a increases and reaches a preset allowable upper limit (set tension), the tension guide 19 is lowered to the detection area by the sensor 24, and the detection signal 24S of the sensor 24 rises from OFF to ON ( Step ST4 in FIG. 4, time t2 in FIG. The drive control unit 40 determines that the tension has exceeded the allowable upper limit due to the detection signal 24S being switched on.

  Here, when the feeding operation of the recording paper 8a by the paper feeding roller pair 26 is started, the drive control unit 40 starts counting the feeding amount of the recording paper 8a. Since a stepping motor is used as the paper feed motor 32, the number of driving steps is counted. When the paper feeding operation is normally performed, the length of the portion of the recording paper 8a between the rotating paper feeding roller pair 26 and the stationary feeding roller pair 25 is shortened as described above, and the tension is reduced. Gradually increases (the slack of the recording paper 8a gradually disappears), and along with this, the tension guide 19 is pushed down and the sensor 24 is turned on.

  However, even if the paper feeding operation is instructed by the drive control unit 40, if the paper feeding operation is not performed, or if the paper feeding amount is insufficient, the tension of the recording paper 8a does not increase, Or the increase is small. In this case, the point at which paper feed should be performed for the paper feed amount when the sensor 24 is turned on, in other words, the number of drive steps of the paper feed motor 32 is the set step number N corresponding to the paper feed amount. Even at the output time (time t3 in FIG. 6), the sensor 24 remains off.

  The drive control unit 40 monitors the paper feed amount at which the sensor 24 is turned on by counting the number of drive steps of the paper feed motor 32 (step ST3 in FIG. 4). If the sensor 24 is not switched on when the number of drive steps reaches a preset number N, it is determined that a problem has occurred in the paper feed operation by the paper feed roller pair 26, and the paper feed The motor 32 is forcibly stopped and a message indicating that an error has occurred is displayed via a display lamp (not shown) of the roll paper printer 1 or an error message is transmitted to the host device 41 to display the host device. An error message is displayed on the monitor screen 41 (step ST4 → ST7 in FIG. 4).

  For example, due to tearing of the recording paper 8a, wear of the paper feed roller 26a, and the like, the recording paper 8a portion is perforated at the paper feed position by the paper feed roller pair 26, and the paper feed roller pair 26 You may not be able to feed. Further, the paper feeding is normally performed due to the step-out of the stepping motor used as the paper feeding motor 32 and the failure of the transmission mechanism that transmits the rotational force of the paper feeding motor 32 to the paper feeding roller 26a (for example, idling of the gear 33). Sometimes not done. In this embodiment, in such a case, the paper feed motor 32 is immediately stopped, the paper feed operation by the paper feed roller pair 26 is stopped, and an error message is displayed. Therefore, it is possible to quickly warn the operator that a problem has occurred in the paper feeding operation. Further, as described below, since the paper feeding operation is monitored using the detection signal 24S of the sensor 24 used for feeding operation control by the feeding roller pair 25, a new detection mechanism for monitoring the paper feeding operation is provided. There is no need to provide.

  Next, the feeding operation control of the recording paper 8a by the drive control unit 40 will be described with reference to FIGS. As described above, the drive control unit 40 monitors whether the tension exceeds the allowable upper limit value based on the output of the sensor 24. In this example, the predetermined operation start delay time DLS is counted from the time point when the set tension is detected (time point t2 in FIG. 6) (steps ST11 and ST12 in FIG. 5), and is delayed by this time. At a later time, the feeding motor 29 is activated, and the feeding operation of the recording paper 8a by the feeding roller 25a is started (step ST13 in FIG. 5, time t4 in FIG. 6). Here, the feeding speed V (25) of the recording paper 8a by the feeding roller 25a rotated by the feeding motor 29 is the feeding speed V (25) of the recording paper 8a by the paper feeding roller 26a rotated by the paper feeding motor 26. 26) is set to a faster speed.

  Since the feeding speed of the recording paper 8a by the feeding roller pair 25 is fast, the feeding amount of the recording paper 8a by the feeding roller pair 25 is larger than the paper feeding amount by the paper feeding roller pair 34, and the recording paper 8a is slack. , The tension is relaxed. Along with this, the tension guide 19 is pushed back upward by the spring force. When the tension of the recording paper 8a returns to the allowable upper limit value or less, the tension guide 19 is moved upward from the detection area of the sensor 24, and the detection signal 24S is turned off again (step ST15 in FIG. 5, time t5 in FIG. 6).

  The drive control unit 40 counts a predetermined operation stop delay time DLE from the time when it is detected that the tension has returned to the allowable upper limit value or less (step ST16 in FIG. 5), and the time after delaying by this time Then, the feeding motor 29 is stopped, and the feeding operation of the recording paper 8a by the feeding roller pair 25 is stopped (step ST17 in FIG. 5, time t6 in FIG. 6). Thereafter, the feeding motor 29 is started and stopped after a predetermined delay time has elapsed according to the on / off state of the sensor 24, and the start and stop of the feeding operation of the recording paper 8a by the feeding roller pair 25 is controlled. 26 assists the feeding operation of the recording paper 8a to suppress an increase in tension acting on the recording paper 8a and to suppress fluctuations in tension.

  Next, in the drive control unit 40, after the recording paper feeding operation by the feeding roller pair 25 is started, the recording paper 8a is fed by the feeding roller pair 25 from the time when the recording paper feeding operation by the paper feeding roller pair 26 is stopped. Count the amount. When the feeding motor 29 is a stepping motor, the number of driving steps is counted. If the feeding amount of the recording paper 8a by the feeding roller pair 25 after the paper feeding operation has stopped exceeds a preset amount, it is determined that an error such as a paper jam has occurred, and the feeding motor 29 Is forcibly stopped and a message indicating that an error has occurred is displayed via a display lamp (not shown) of the roll paper printer 1, or an error message is transmitted to the host device, and the monitor screen of the host device is displayed. An error message is displayed above (steps ST14 and ST18 in FIG. 5).

  In a normal transport operation, when the feeding operation of the recording paper 8a by the paper feeding roller pair 26 located on the downstream side of the feeding roller pair 25 is finished, the recording paper 8a fed by the feeding roller pair 25 is slackened, The tension is lowered, the tension guide 19 is pushed up by the spring force, the sensor 24 is turned off, and the recording paper feeding operation of the feeding roller pair 25 should stop.

  If the feeding operation by the feeding roller pair 25 continues after the feeding operation by the paper feeding roller pair 26 is stopped, the portion of the recording paper 8a located between these roller pairs 26 and 25 is in a paper jam state. Therefore, it is conceivable that the tension acting on the portion of the recording paper 8a stretched over the tension guide 19 is not released. When the feeding operation of the recording paper 8a is continued by the feeding roller pair 25 in the paper jam state, a large amount of the recording paper 8a is fed out to a portion between the feeding roller pair 25 and the paper feeding roller pair 26, and the recording paper 8a is fed to this portion. The recording paper 8a is clogged, the recording paper 8a is creased, and the recording paper 8a is broken. In such a case, the feeding motor 29 is immediately stopped, the feeding operation by the feeding roller pair 25 is stopped, and an error message is displayed, so that the operator is quickly warned of an error condition such as a paper jam. it can.

  Further, even when the conveyance of the paper feed roller pair 26 is started or stopped, the tension can be continuously monitored to determine a conveyance failure. Further, the transport amount of the recording paper may be calculated from a predetermined point in time of transport in addition to the case of calculating from the start of transport.

(Other embodiments)
In the above example, the present invention is applied to a serial type roll paper printer. However, the present invention is also applicable to a line type roll paper printer. In the above example, the present invention is applied to an ink jet type roll paper printer. However, the present invention can be similarly applied to a roll paper printer including various print heads such as a thermal head. .

1 roll paper printer, 2 printer body, 2a exterior case, 2b opening, 3 open / close lid, 3A closed position, 3B open position, 3a lid frame, 3b lid cover, 4 recording paper discharge port, 5 paper ejection guide, 6 lid Open / close lever, 7 roll paper storage section, 8 roll paper, 8a recording paper, 11 printer body frame, 12 platen unit, 13 inkjet head, 14 head carriage, 15 carriage guide shaft, 16 carriage motor, 17 timing belt, 18 platen, 19 Tension guide, 21 and 22 arrows, 23 Recording paper transport path, 24 sensor, 24S detection signal, 25 feed roller pair, 25a feed roller, 25b driven roller, 26 paper feed roller pair, 26a paper feed roller, 26b driven low -, 27 Conveying roller pair, 27a Conveying roller, 27b Driven roller, 28 Reduction gear train, 29 Feeding motor, 30 Roller support lever, 31 Buffer spring, 32 Paper feed motor, 33 Reduction gear train, 40 Drive control unit, 41 Upper Equipment, 42/43/44 Motor driver, 45 Head driver, 46 Storage area, DLE operation stop delay time, DLS operation start delay time, V (25) Feeding speed, V (26) Paper feed speed, N Number of set steps

Claims (6)

The portion of the long recording paper located between the paper feeding position by the feeding roller and the paper feeding position by the paper feeding roller is bridged over a displaceable tension guide to which a predetermined urging force is applied,
Monitoring whether or not the tension generated in the recording paper reaches a predetermined set tension during the conveyance of the recording paper by the paper feed roller;
When the tension generated on the recording paper reaches the set tension during the conveyance of the recording paper by the paper feed roller, the recording paper is fed out by the feeding roller until the tension falls below the set tension. Done
Even when the conveyance amount of the recording paper from the predetermined time point of conveyance of the recording paper by the paper feed roller reaches a time point when the predetermined conveyance amount should be reached, the tension generated in the recording paper becomes the set tension. If not, it is determined that a defect has occurred in the recording paper conveyance operation by the paper feed roller. In claim 1,
A method for monitoring a recording paper conveyance state of a printer, wherein whether or not a tension generated on the recording paper has reached the set tension is monitored based on a displacement amount of the tension guide. In claim 1 or 2,
Using the stepping motor driven by open loop control, the paper feed roller is rotationally driven to convey the recording paper,
A method for monitoring a recording paper conveyance state of a printer, characterized in that a point in time when the conveyance amount of the recording paper by the paper feed roller should reach the set conveyance amount is determined based on the number of driving steps of the stepping motor. A print head;
A paper feed roller that transports a long recording paper via a printing position by a print head, and
A feed roller for feeding the recording paper toward the paper feed roller;
The transfer portion of the recording paper that is stretched between the paper feed position by the feed roller and the paper feed position by the paper feed roller can be pressed with a predetermined biasing force, and is displaced against the biasing force. A tension guide that can
A sensor that detects whether or not the tension generated in the bridging portion of the recording paper has reached a predetermined set tension;
Control means for controlling the driving of the paper feed roller and the feed roller,
When the control means detects that the tension generated in the bridging portion of the recording paper reaches the set tension based on the detection signal of the sensor at least during conveyance of the recording paper, the tension is set to the setting tension. The recording paper is fed out by the feeding roller until the tension is less than the tension, and even if the recording paper transport amount by the paper feed roller reaches a preset transport amount, the recording paper is generated. When the tension does not reach the set tension, it is determined that a defect has occurred in the recording paper transport operation by the paper feed roller. In claim 4,
The printer according to claim 1, wherein the sensor detects whether or not the tension guide is displaced by a predetermined displacement amount. In claim 4 or 5,
A stepping motor that rotationally drives the paper feed roller;
The printer according to claim 1, wherein the control unit detects a point in time when the conveyance amount of the recording paper by the paper feed roller should reach the set conveyance amount based on the number of driving steps of the stepping motor.

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