JP2008127108A - Method of detecting failure of paper detector of rolled paper printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolled paper printer capable of detecting a failure of a paper detector. <P>SOLUTION: The rolled paper printer 1 comprises the paper detector 40 for detecting whether a recording paper 11a exists in a conveyance path passing through a printing position of an ink jet head 14 or not, and allows conveyance of the recording paper by a feeding motor 37 during the time when existence of the recording paper 11a is detected, and inhibits conveyance when non-existence of the recording paper 11a is detected. A computing means 50 for the number of total steps is provided to compute a cumulative value of the amount of conveyance of the recording paper 11a conveyed along the conveyance path as the number of total steps of the feeding motor 37, and when the number of total steps reaches a specified number of steps larger than the length of a rolled paper by one roll of the rolled paper, a failure of the paper detector 40 is detected on the basis of a determination that conveyance of the recording paper 11a in the feeding direction by the feeding motor 37 before the number of total steps reaches the specified number of steps is inhibited if the paper detector 40 is normally operated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a roll paper printer including a paper detector that detects whether or not a long recording paper fed out from a roll paper is drawn along a conveyance path passing through a printing position by a print head, and More specifically, the present invention relates to a paper detector failure detection method for a roll paper printer that detects a failure of a paper detector based on a transport amount of recording paper sent along a transport path.

  The roll paper printer includes a conveyance path for conveying a long recording paper fed out from the roll paper stored in the roll paper storage unit toward a recording paper discharge port via a printing position by a print head. Yes. A pair of paper feed rollers driven by a paper feed motor such as a stepping motor is arranged in the transport path. When the roll paper is replaced, the recording paper drawn from the roll paper in the roll paper storage unit is used as these rollers. Set to pass between pairs.

  If the recording paper is not set correctly, the printing operation by the print head is performed without conveying the recording paper. For example, when an inkjet head is used as the print head, the ejected ink droplets adhere to components such as a platen that defines the printing position, and stain them. A similar problem occurs when the recording paper runs out.

Therefore, a paper detector is arranged in the conveyance path of the roll paper printer. The paper detector detects whether the recording paper is pulled out along the conveyance path. Generate a warning to that effect. Patent Document 1 discloses a roll paper printer provided with such a paper detector. In the roll paper printer disclosed herein, when the opening / closing lid of the roll paper storage unit is opened, the printing position by the print head is adjusted from the roll paper storage unit so that the roll paper can be easily replaced. The conveyance path to the recording paper discharge port via the opening is in an open state. Further, Patent Document 2 discloses a roll paper printer including a paper detector that detects the remaining amount of recording paper using a mark provided in advance on the roll paper.
JP 2002-264414 A JP 2001-97621 A

  Here, when the paper detector fails, there is a risk of falling into an output state indicating that the recording paper has been detected even though the recording paper has not been pulled out along the conveyance path. When such an erroneous detection state occurs, there are problems such as contamination of parts such as the platen with ink droplets as described above.

  The paper detector is composed of a photo sensor, a magnetic sensor, a micro switch, and the like, and may be in a false detection state due to its initial failure or aging. For example, when an optical paper detector composed of a photocoupler and a detection lever is used, it may be caused by poor mounting of the detection lever, malfunction of the circuit board of the photocoupler, malfunction of the circuit board or detection lever due to aging, etc. Thus, it will fall into a false detection state. However, in the past, such a failure of the paper detector could not be detected.

  An object of the present invention is to provide a failure detection method capable of detecting a failure of a paper detector for detecting whether or not a long recording paper is pulled out along a conveyance path in a roll paper printer, and An object of the present invention is to propose a roll paper printer capable of detecting a failure of a paper detector by the failure detection method.

  In order to solve the above problems, the present invention is directed to whether a long recording paper fed out from a roll paper stored in a roll paper storage unit is drawn out along a conveyance path passing through a printing position by a print head. This is a paper detector failure detection method for a roll paper printer that includes a paper detector for detecting whether or not the recording paper is in an output state indicating that there is no recording paper. Then, the calculation of the cumulative value of the transport amount of the recording paper sent out along the transport path is started from a predetermined time, and the cumulative value of the transport amount is the recording paper length for at least one roll of the roll paper. Whether or not the specified transport amount corresponding to the height is monitored, and if the cumulative value of the transport amount exceeds the specified transport amount, it is determined that the paper detector is malfunctioning. Yes.

  When a new roll paper is stored in the roll paper storage unit, and a long recording paper is fed from the roll paper and conveyed along the conveyance path to perform a printing operation, the time when the roll paper runs out, that is, the recording paper The point in time when the recording paper disappears is when the recording paper for one roll of roll paper has been conveyed. When the recording paper for one roll of roll paper has been transported, there is no recording paper on the transport path. Also, when the calculation of the cumulative value of the recording paper transport amount is started from a predetermined time after the roll paper replacement, when the recording paper having a length shorter than the recording paper for one roll of paper has been transported Since the recording paper has already been used, there is no recording paper on the conveyance path. In any case, there is no recording paper on the conveyance path when the recording paper for at least one roll of roll paper has been conveyed. When there is no recording paper on the conveyance path, the paper detector detects the absence of recording paper, and thereafter, the conveyance of the recording paper is prohibited. The fact that the cumulative value of the transport amount exceeds the specified transport amount corresponding to the length of the recording paper for one roll of roll paper means that the paper detector detects the presence of recording paper even though there is no recording paper. Means that Therefore, in this case, it can be determined that the paper detector has failed.

  Here, the calculation start point of the accumulated value of the conveyance amount for detecting the failure of the paper detector may be set as the time point when the roll paper stored in the roll paper storage unit is replaced.

  In order to know when the roll paper has been replaced, the open / close state of the open / close lid for opening and closing the roll paper storage unit may be monitored. That is, when the opening / closing lid is opened for a predetermined time or more, it can be determined that the roll paper in the roll paper storage unit has been replaced. In this case, the calculation of the cumulative value of the conveyance amount of the recording paper may be started from the time when the opening / closing lid is closed.

  In addition, when the open / close lid is accidentally opened, the open / close lid is often immediately closed. In this case, the open / close lid is generally closed within 2 seconds. Therefore, if it is determined that the roll paper in the roll paper storage unit has been replaced when the opening / closing lid is open for 2 seconds or longer, such an erroneous opening / closing may be determined as the roll paper has been replaced. Absent.

  When judging the roll paper replacement time based on the opening and closing of the open / close lid, if monitoring of the open / close state of the open / close lid becomes impossible, the accumulated value of the transport amount is reset when the monitoring is restored. It is desirable to start a new calculation of the cumulative value of the carry amount from the time point.

  For example, when the power supply of the roll paper printer is cut off, the open / close state of the open / close lid cannot be monitored. In this state, the roll paper may be replaced with a new roll paper. When the power is turned on again after the roll paper is replaced, if the transport amount of the recording paper is added to the cumulative value of the transport amount before turning off the power, the paper is transported before the roll paper after replacement is exhausted. The accumulated value exceeds the length of the recording paper for one roll of roll paper. As a result, it is erroneously determined that the paper detector is faulty even though there is recording paper in the transport path and the paper detector has detected it normally. According to the present invention, such erroneous determination can be avoided.

  Next, if the specified transport amount for defining the point in time when the failure of the paper detector is detected is set to an amount 10% larger than the recording paper length for one roll of roll paper, Therefore, it is possible to determine the failure of the paper detector when the recording paper runs out.

  Further, in the present invention, when it is determined that the paper detector has failed, it is desirable to generate a warning to that effect and disable the recording paper transport operation and the printing operation by the print head. .

  Further, when a stepping motor is used as the paper feeding motor, the cumulative value of the recording paper conveyance amount can be calculated based on the number of steps for driving the stepping motor in the recording paper feeding direction.

  Next, the present invention is a paper for detecting whether or not a long recording paper fed out from a roll paper stored in a roll paper storage unit is drawn out along a conveyance path passing through a printing position by a print head. A roll paper printer that includes a detector and prohibits the recording paper transport operation when the paper detector is in an output state indicating that there is no recording paper, and is an open / close for opening and closing the roll paper storage unit An open / close detector that monitors the open / closed state of the lid, a calculation unit that calculates a cumulative value of the transport amount of the recording paper that is sent out along the transport path, and a cumulative value of the transport amount that is calculated by the calculation unit. Monitoring means for monitoring whether or not a specified transport amount corresponding to a recording paper length for at least one roll of the roll paper is exceeded, and when the cumulative value of the transport amount exceeds the specified transport amount, The paper detector is defective. Failure detecting means for determining, and when the opening / closing lid is open for a predetermined time or more, the calculating means calculates the accumulated value of the transport amount from the time when the opening / closing lid is closed. It is characterized by starting.

  Here, when the open / closed state of the open / close lid is not monitored by the open / close detector, the calculation unit resets the accumulated value of the transport amount to zero and can monitor the state. The calculation of the accumulated value of the transport amount is newly started from the time when the state is returned to the correct state.

  In addition, the state in which the open / close state of the open / close lid cannot be monitored by the open / close detector is a state in which the power is shut off, and the time when the monitor returns to the monitorable state is a time when the power is turned on again. It is characterized by that.

  Further, in the present invention, when the initialization operation is performed in a state where the open / close detector can monitor the open / closed state of the open / close lid, the non-volatile storage for temporarily saving the accumulated value of the transport amount by the calculating means. It has a characteristic memory. When an initialization operation such as hardware reset is performed, since the power is not cut off, the open / close detector can detect the open / closed state of the open / close lid. In such a case, it can be determined whether or not the roll paper has been replaced. Therefore, instead of starting the calculation of the cumulative value of the transport amount of recording paper from zero after the initialization operation, the cumulative value up to that time is temporarily saved in the non-volatile memory, and continues after the initialization operation is completed. It is desirable to calculate the cumulative value of the transport amount.

  Furthermore, in the present invention, when it is detected that the paper detector is faulty, warning means for generating a warning to that effect, and when it is detected that the paper detector is faulty, Has a print control means for disabling the printing operation by the print head.

  Further, in the present invention, a stepping motor that transports the recording paper along the transporting path is provided, and the calculation unit is configured to perform the recording based on the number of steps that the stepping motor is driven in the feeding direction of the recording paper. It is characterized in that a cumulative value of the amount of paper transport is calculated.

  The present invention focuses on the point that the recording paper does not exist on the conveyance path after at least one roll of recording paper has been conveyed. When the paper detector detects that there is no recording paper on the transport path, the recording paper transport operation is prohibited thereafter. Therefore, when the cumulative value of the transport amount exceeds the specified transport amount corresponding to the recording paper length for one roll of roll paper, it can be determined that the paper detector has failed at that time. . Therefore, according to the present invention, it is possible to reliably avoid the adverse effects caused by the erroneous detection of the paper detector.

  Embodiments of a roll paper printer to which the present invention is applied will be described below with reference to the drawings.

(overall structure)
FIG. 1 is an external perspective view of an ink jet type roll paper printer to which the present invention is applied, and FIG. 2 is an external perspective view of a state in which the opening / closing lid is fully opened.

  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. A recording paper discharge port 4 through which the issued receipt is discharged is formed on the front surface of the outer case 2a 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. The left side of the opening / closing lid 3 is an operation surface 2b, in which a warning lamp 7 (warning means) made of LEDs, a power switch 8, and the like are arranged.

  When the lid opening / closing lever 6 is operated, the opening / closing lid 3 is unlocked. When the paper discharge guide 5 is pulled forward, as shown in FIG. 2, the opening / closing lid 3 opens until it is substantially horizontal forward with the lower end as a center. When the opening / closing lid 3 is opened, the roll paper storage unit 10 formed inside the printer main body 2 is opened. Roll paper 11 is stored in the roll paper storage unit 10. The roll paper 11 has a configuration in which a long recording paper 11a having a certain width is wound.

  FIG. 3 is a schematic longitudinal sectional view showing the internal structure of the roll paper printer 1, with the outer case 2a removed. A recording paper guide 12 having a predetermined width is disposed horizontally in the front-rear direction of the printer at the rear portion above the roll paper storage unit 10 inside the printer. On the front side of the recording paper guide 12, a platen guide 13 having a predetermined width is disposed horizontally in the front-rear direction of the printer at a position one step higher. An ink jet head 14 is disposed directly above the platen guide 13. The nozzle surface 14a of the inkjet head 14 is opposed to the upper surface 13a of the platen guide 13 with a certain gap, and the printing position is defined by the upper surface 13a.

  The inkjet head 14 is mounted on a carriage 15, and the carriage 15 is supported so as to be movable in the printer width direction along a carriage guide 16 extending horizontally in the printer width direction. The carriage 15 is connected to a timing belt 17 that extends in the printer width direction, and the timing belt 17 is driven by a carriage motor 18. When the carriage motor 18 is driven, the ink-jet head 14 mounted on the carriage 15 moves in the printer width direction, and the ink-jet head 14 is driven in synchronization with this movement, and passes through the printing position (13a). Printing is performed on the surface.

  On the other hand, a scissors type recording paper cutting device 20 is disposed at the recording paper discharge port 4. The fixed blade 21 of the recording paper cutting device 20 is vertically arranged in the upward state, and the movable blade 22 is vertically arranged in the downward direction. When the movable blade 22 is swung in the vertical direction with one end in the printer width direction as a fulcrum by the drive mechanism 23, the contact point with the fixed blade 21 moves in the printer width direction, and the recording paper 11a positioned therebetween is moved. It can be cut in the width direction.

  4 and 5 are a perspective view and a plan view showing the internal structure of the roll paper printer 1 in a state where the inkjet head 14 and its moving mechanism are omitted. With reference to FIG. 3 to FIG. 5, a recording paper transport mechanism that transports the recording paper 11 a fed from the roll paper 11 via the printing position will be described.

  First, between the recording paper guide 12 and the platen guide 13, a first paper feed roller 34 is stretched horizontally in the printer width direction. A first paper pressing roller 35 having a predetermined width is pressed from the lower side to the first paper feeding roller 34 with a predetermined pressing force. The first paper pressing roller 35 is disposed at a position offset to the right side (the guide surface 33 side) from the center of the conveyance path width defined by the guide surfaces 32 and 33. The first paper feed roller 34 is driven by a paper feed motor 37 via a belt-pulley type transmission mechanism 36. The paper feed motor 37 is a stepping motor, and when it is driven by one step, the recording paper 11a is correspondingly fed by a predetermined transport amount along the transport path.

  Next, a second paper feed roller 38 is disposed at the front end portion of the platen guide 13. The second paper feed roller 38 of this example has a configuration in which a left paper feed roller 38a and a right paper feed roller 38b are coaxially connected by a common roller shaft 38c. The left side paper feed roller 38a and the right side paper feed roller 38b are disposed at symmetrical positions. A second paper pressing roller 39 is pressed from the upper side to the second paper feeding roller 38 having this configuration. The second paper pressing roller 39 also includes a left paper pressing roller 39a and a right paper pressing roller 39b. The left paper pressing roller 39a presses the left paper feeding roller 38a with a predetermined pressing force, and the right paper pressing roller 39b presses the right paper feeding roller 38b with the same pressing force.

  Here, a paper detector 40 for detecting the presence or absence of the recording paper 11 a conveyed from the recording paper guide 12 through the printing position by the front platen guide 13 is disposed above the recording paper guide 12. Has been. The paper detector 40 includes a detection lever 41 pushed up by a portion 11b (see FIG. 3) of the recording paper 11a that is conveyed between the recording paper guide 12 and the platen guide 13, and the detection lever. And an optical type photocoupler 42 for detecting 41.

  The detection lever 41 is supported so as to be able to swing in the vertical direction around the central portion in the front-rear direction of the printer, and is biased in a direction in which the tip portion 41a rotates downward by a biasing means (not shown). Hits the recording paper portion 11b from above. The rear end portion 41b of the detection lever 41 can swing up and down through the detection region of the photocoupler 42. When the front end portion 41a is in contact with the recording paper portion 11b, the rear end portion 41b is detected by the photocoupler 42. Located in. When the recording paper portion 11b disappears, that is, when the recording paper 11a disappears, the detection lever 41 rotates in the direction in which the leading end moves downward, and the rear end 41b moves upward to deviate from the detection area. As a result, since the output of the photocoupler 42 changes, the presence or absence of the recording paper 11a can be detected based on this output.

  In the roll paper printer 1 configured as described above, the recording paper 11a drawn from the roll paper 11 stored in the roll paper storage unit 10 is recorded along the conveyance path indicated by the thick dashed line in FIG. The second paper feed roller 38 and the second paper press roller 39 are guided by the paper guide 12 and pass between the first paper feed roller 34 and the first paper press roller 35 through the upper surface 13a (printing position) of the platen guide 13. And is pulled out from the recording paper discharge port 4 to the outside.

  In this state, when the first paper feed roller 34 and the second paper feed roller 38 are rotated by driving and controlling the paper feed motor 37, the recording paper 11a is fed by a constant transport amount. The inkjet head 14 is driven in synchronization with the paper feed of the recording paper 11a, and printing is performed on the surface of the recording paper 11a passing through the printing position. Thereafter, the conveyance is stopped in a state where the recording paper 11a after printing is discharged from the recording paper discharge port 4, and the recording paper 11a is cut by the recording paper cutting device 20, and a printed recording paper piece is obtained as a receipt of a predetermined length. publish.

  Next, when the recording paper 11a sent out from the roll paper 11 is finished and disappears from the conveyance path, the output state of the paper detector 40 becomes a state indicating that there is no recording paper 11a. In such an output state, the transport operation of the recording paper 11a by the paper feed motor 37 is prohibited until the output state of the paper detector 40 becomes an output state indicating that the recording paper 11a is present.

  Here, the platen guide 13 facing the ink jet head 14, the first paper pressing roller 35 facing the first paper feed roller 34, and the second paper feed roller 38 are mounted on the opening / closing lid 3 side. Yes. Therefore, as shown in FIG. 2, when the opening / closing lid 3 is opened, between the first paper pressing roller 35 and the first paper feeding roller 34 and between the second paper feeding roller 38 and the second paper pressing roller 39. Opens to open the transport path.

  Further, since the paper detector 40 is disposed on the printer main body 2 side, when the opening / closing lid 3 is opened to open the transport path and the recording paper 11a is in a relaxed state, the leading end 41a of the detection lever 41 is moved. The rear end 41b moves out of the detection region of the photocoupler 42. Therefore, if no failure has occurred in the paper detector 40, the output state of the paper detector 40 is in a state of indicating no paper when the open / close lid 3 is opened.

  On the other hand, when the roll paper 11 is loaded into the roll paper storage unit 10 and then the recording paper 11a fed out from the roll paper 11 is drawn out to a length exceeding the recording paper discharge port 4 and the opening / closing lid 3 is closed, the recording paper is first. A state of being automatically pulled out from the recording paper discharge port 4 through the printing position defined by the upper surface 13a of the platen guide 13 between the paper feeding roller 34 and the first paper pressing roller 35 is automatically formed.

  An opening / closing detector 45 (see FIG. 6) is attached in the vicinity of the opening / closing lid 3 so that the opening / closing of the opening / closing lid 3 can be detected. The open / close detector 45 includes a photo sensor, a magnetic sensor, a micro switch, and the like.

(Control system)
FIG. 6 is a schematic block diagram showing a control system of the roll paper printer 1. The control system of the roll paper printer 1 is mainly configured by a control unit 30 including a CPU, a ROM, and a RAM 56. Print data and the like are supplied to the control unit 30 from an upper device such as a computer via an interface 31. A paper detector 40 and an open / close detector 45 are connected to the input side of the control unit 30, and the presence or absence of the recording paper 11 a is detected based on an input signal from the paper detector 40, and the input from the open / close detector 45. Based on the signal, the open / close state of the open / close lid 3 is detected. A timer 47, a power switch 8, and a dip switch 9 are connected to the input side of the control unit 30. The timer 47 counts the time during which the open / close lid 3 is open based on an input signal from the open / close detector 45. The dip switch 9 sets a processing operation performed by the control unit 30 when the power switch 8 is operated. One of the processing operations of power-off, hardware reset, and software reset is performed. Selected and set. Further, a nonvolatile memory 48 is connected to the control unit 30.

  An inkjet head 14, a carriage motor 18 and a paper feed motor 37 are connected to the output side of the control unit 30 via a head driver 14b and motor drivers 18a and 37a, and a warning lamp 7 is connected via an LED driver 7a. Is connected. Here, while the control unit 30 detects an input signal indicating that there is no recording paper 11a in the conveyance path from the paper detector 40, the conveyance operation of the recording paper 11a by the paper feed motor 37 is prohibited.

  The control unit 30 counts the step for controlling the drive of the paper feed motor 37 in the feed-out direction, calculates the total step number (cumulative value), and the calculated total step number is the specified step number. Is provided with a monitoring means 55 for monitoring whether or not the threshold value is exceeded, and a RAM 56. The total step number calculating means 50 includes a counting means 51 and a count resetting means 52. The counting means 51 is a step in which the paper feed motor 37 is driven and controlled in the feeding direction while the opening / closing lid 3 is closed. Count the number. The accumulated value of the counted steps is stored in the RAM 56 as the total number of steps.

  The count reset means 52 resets the total number of steps stored in the RAM 56 to zero. When the total number of steps is reset to zero, the number of steps starts counting from zero. The total number of steps is reset when it is determined that the roll paper 11 has been replaced by opening the opening / closing lid 3. In this example, the total number of steps is reset when it is detected that the open / close lid 3 has been opened for a predetermined time of 2 seconds or more.

  Next, the monitoring unit 55 monitors the total number of steps stored in the RAM 56, and determines whether this has reached the specified number of steps. For example, every time a print job such as receipt printing ends, it is determined whether or not the total number of steps has reached a specified number of steps. The specified number of steps is equal to or greater than the number of steps necessary to transport the entire length of the recording paper 11a fed from the new roll paper 11, and in this example, the viewpoint of avoiding erroneous detection of a failure of the paper detector 40 Therefore, the value is about 10% larger than the required number of steps.

  When the monitoring unit 55 detects that the total number of steps has reached the specified number of steps, the control unit 30 determines that the paper detector 40 has failed. If the paper detector 40 is operating normally, the conveyance of the recording paper by the paper feed motor 37 is prohibited before the specified number of steps is reached, and the total number of steps has reached the specified number of steps by the monitoring means 55. This is because there is no wrinkle detected. Therefore, the control unit 30 and the monitoring unit 55 function as a failure detection unit for the paper detector 40.

  Further, when a failure of the paper detector 40 is detected, the control unit 30 drives the warning lamp 7 in a predetermined form via the LED driver 59 to generate a warning that the paper detector 40 has failed. Let Further, if the printing operation is resumed while the paper detector 40 is in a failure state, the printing operation by the inkjet head 14 is disabled because there is a possibility that printing is repeated without the recording paper 11a.

(Example of paper detector failure detection operation)
Next, a typical flow of the failure detection operation of the paper detector 40 will be described with reference to the flowchart of FIG.

  When there is a print command and the recording paper is conveyed by the paper feed motor 37 (step ST1), the total number of steps is updated by the total number of steps calculating means 50 and stored in the RAM 56 (step ST2). The monitoring means 55 compares the total number of steps held in the RAM 56 with a specified number of steps at a predetermined timing (step ST3). When the total number of steps is equal to or greater than the specified number of steps, the control unit 30 determines that the paper detector 40 is out of order. (Step ST4).

  That is, if the paper detector 40 is operating normally, the conveyance of the recording paper 11a by the paper feed motor 37 is prohibited before reaching the specified number of steps, and the total number of steps does not reach the specified number of steps. . Accordingly, when the cumulative value of the transport amount of the recording paper 11a exceeds the specified number of steps corresponding to the recording paper length for one roll of roll paper, it can be determined that the paper detector 40 is out of order. it can.

  If the control unit 30 determines that the paper detector 40 has failed, the warning lamp 7 is driven in a predetermined form via the LED driver 59 to generate a warning that the paper detector 40 has failed. Further, the printing operation by the inkjet head 14 is disabled.

  When it is detected that the open / close lid 3 has been opened (step ST5), the timer 47 counts the time during which the open / close lid 3 is open. When it is detected that the opening / closing lid 3 is closed within 2 seconds (step ST6), it is determined that the opening / closing lid 3 is not opened for replacing the roll paper but is opened by mistake. To do. When the open / close lid 3 is closed after being opened for more than 2 seconds, the count resetting means 52 resets the total number of steps held in the RAM 56 to zero (steps ST6 to ST7). That is, it is determined that the roll paper 11 has been replaced, and thereafter, counting of the number of steps starts from zero.

  Next, the following processing is also performed in this example. First, when the open / close state of the open / close lid 3 cannot be detected and it is unclear whether or not the roll paper 11 has been replaced, the total number of steps stored and held in the RAM 56 is reset. In this case, the total number of steps is reset when the open / close detector 45 returns from the undetectable state to the detectable state.

  The state in which the open / close state of the open / close lid 3 cannot be detected includes a state in which firmware installed in the roll paper printer 1 is being rewritten, or immediately after a hard reset switch (not shown) is operated. Is in an open state, an error has occurred due to indefinite operations of mechanical elements such as the inkjet head 14 and its moving mechanism and paper feed / conveying mechanism, and an error informing the life of the product has occurred. . When falling into such a state, the control unit 30 cannot obtain the signal of the open / close detector 45 and cannot detect the open / closed state of the open / close lid 3.

  The total number of steps stored and held in the RAM 56 is erased when the power switch 8 of the roll paper printer 1 is turned off and the power is shut off. Therefore, even when the power is turned on, the total number of steps is reset and counting starts from zero.

  Next, when a hardware reset or a software reset is performed by operating the power switch 8 according to the setting of the dip switch 9, the count reset means 52 does not reset the total number of steps. This is because the open / close detector 45 can detect the open / close state of the open / close lid 3 during these initialization operations.

  In this case, if the hardware reset is performed by operating the power switch 8, the total number of steps stored in the RAM 56 is lost, so the control unit 30 is stored in the RAM 56 when the power switch 8 is operated. The total number of steps that has been stored is temporarily saved in the nonvolatile memory 48. After the initialization operation is completed, the saved value is read into the RAM 56. Thereafter, the total number of steps is calculated by adding the value counted by the counting means 51 to the read value.

  It is to be noted that the provisions stipulate the opening time (2 seconds in this example) of the opening / closing lid 3 for determining whether or not the roll paper 11 has been replaced and the time point at which it is determined whether or not the paper detector 40 is out of order. If the number of steps can be changed in accordance with the use environment of the user, the failure of the paper detector 40 can be accurately detected. When a motor other than the stepping motor is used as the paper feed motor 37 for transporting the recording paper 11a, the cumulative value of the transport amount of the recording paper 11a is calculated based on the rotation amount of the paper feed motor in the feed direction. be able to.

1 is an external perspective view of a roll paper printer to which the present invention is applied. FIG. 2 is an external perspective view of a roll paper printer with an open / close lid open. It is a schematic longitudinal cross-sectional view which shows the internal structure of a roll paper printer. It is a perspective view which shows the internal structure of a roll paper printer. It is a top view which shows the internal structure of a roll paper printer. FIG. 2 is a schematic block diagram illustrating a control system of a roll paper printer. It is a flowchart which shows the typical flow of the failure detection operation | movement of a roll paper detector.

Explanation of symbols

1. Roll paper printer 3. Open / close lid 4. Recording paper outlet 5. Discharge guide 6. Cover open / close lever 7. Warning lamp 8. Power button 9. Dip switch 10. Roll paper storage 11, roll paper, 11 a recording paper, 11 b recording paper section, 12 recording paper guide, 13 platen guide, 13 a upper surface (printing position), 14 ink jet head, 14 a nozzle surface, 15 carriage , 16 Carriage guide, 17 Timing belt, 18 Carriage motor, 25 Paper detector, 30 Control unit, 31 Interface, 32, 33 Guide surface, 34 First paper feed roller, 35 First Paper press roller, 37-paper feed motor, 38-second paper feed roller, 39-second paper press roller, 40-paper detector, 41-detection lever, 42-photocoupler, 45 Closing detector, 47 timer, 48-volatile memory, 50-total step number calculating means, 51 count means 52 counts the reset means 55 and monitoring means, 56 - RAM

Claims (15)

A paper detector for detecting whether or not a long recording paper fed out from the roll paper stored in the roll paper storage unit is drawn along a conveyance path passing through a printing position by the print head; A paper detector failure detection method for a roll paper printer that prohibits the recording paper transport operation when the detector is in an output state indicating that there is no recording paper,
The calculation of the cumulative value of the conveyance amount of the recording paper sent out along the conveyance path is started from a predetermined time point,
Monitoring whether the cumulative value of the carry amount exceeds a prescribed carry amount corresponding to a recording paper length for at least one roll of the roll paper;
A paper detector failure detection method for a roll paper printer, wherein when the cumulative value of the transport amount exceeds the specified transport amount, it is determined that the paper detector has failed. In claim 1,
A paper detector failure detection method for a roll paper printer, characterized in that a calculation start time of the accumulated value of the transport amount is a time when roll paper stored in the roll paper storage unit is replaced. In claim 2,
Monitoring the open / close state of the open / close lid for opening and closing the roll paper storage unit;
When the opening / closing lid is open for a predetermined time or more, it is determined that the roll paper in the roll paper storage unit has been replaced,
A paper detector failure detection method for a roll paper printer, characterized in that the time when the opening / closing lid is closed is the calculation start time. In claim 3,
A paper detector failure detection method for a roll paper printer, wherein the roll paper in the roll paper storage unit is determined to have been replaced when the open / close lid is open for 2 seconds or longer. In claim 3,
When monitoring of the open / closed state of the open / close lid becomes impossible, the cumulative value of the transport amount is reset at the time when the monitor returns to the state where the monitoring is possible, and the cumulative value of the transport amount is calculated from the time point A paper detector failure detection method for a roll paper printer, characterized by starting a new process. In claim 5,
When monitoring of the open / closed state of the open / close lid is disabled, the case where the roll paper printer is turned off is included,
In this case, a paper detector failure detection method for a roll paper printer, wherein the calculation of the cumulative value of the transport amount is newly started from the time when the power is turned on again. In any one of claims 1 to 6,
A paper detector failure detection method for a roll paper printer, wherein the specified transport amount is set to an amount 10% larger than a recording paper length for one roll of the roll paper. In any one of claims 1 to 7,
When it is determined that the paper detector is out of order, a roll paper that generates a warning to that effect and disables the recording paper transport operation and the print head printing operation. Printer paper detector failure detection method. In any one of claims 1 to 8,
Transporting the recording paper along the transport path using a stepping motor;
A paper detector failure detection method for a roll paper printer, wherein a cumulative value of the transport amount of the recording paper is calculated based on the number of steps for driving the stepping motor in the feeding direction of the recording paper. A paper detector for detecting whether or not a long recording paper fed out from the roll paper stored in the roll paper storage unit is drawn along a conveyance path passing through a printing position by the print head; When the detector is in an output state indicating that there is no recording paper, it is a roll paper printer that prohibits the recording paper conveyance operation,
An open / close detector for monitoring an open / close state of an open / close lid for opening / closing the roll paper storage unit;
A calculation means for calculating a cumulative value of the conveyance amount of the recording paper sent out along the conveyance path;
Monitoring means for monitoring whether or not the cumulative value of the carry amount calculated by the calculating means exceeds a prescribed carry amount corresponding to a recording paper length for at least one roll of the roll paper;
When the accumulated value of the carry amount exceeds the specified carry amount, it has failure detection means for judging that the paper detector is broken,
The calculating means starts the calculation of the accumulated value of the transport amount from the time when the opening / closing lid is closed when the opening / closing lid is open for a predetermined time or more. . In claim 10,
The calculation means resets the accumulated value of the transport amount to zero and returns to a monitorable state when the open / close state of the open / close lid by the open / close detector returns from a disabled state to a possible state. A roll paper printer, wherein the calculation of the cumulative value of the carry amount is newly started from the time of return. In claim 11,
The state in which the open / close state of the open / close lid cannot be monitored by the open / close detector is a state in which the power supply is shut off,
The roll paper printer according to claim 1, wherein the time when the monitor is restored is a time when the power is turned on again. In any one of claims 10 to 12,
A non-volatile memory for storing and holding the cumulative value of the transport amount by the calculating means;
When the initialization operation is performed in a state where the open / close state of the open / close lid can be monitored by the open / close detector, the calculation means temporarily stores the accumulated value so that the accumulated value of the transport amount is not initialized. A roll paper printer which is evacuated to the non-volatile memory. In any one of claims 10 to 13,
Warning means for generating a warning to that effect when it is detected that the paper detector is faulty;
A roll paper printer comprising: a print control unit that disables a printing operation by the print head when it is detected that the paper detector is out of order. In any one of claims 10 to 14,
A stepping motor for transporting the recording paper along the transport path;
The roll paper printer, wherein the calculating means calculates a cumulative value of the transport amount of the recording paper based on the number of steps in which the stepping motor is driven in the recording paper feeding direction.

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