JP2017222084A - Printer and control method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer capable of inhibiting characters, figures and the like to be printed from being printed with deviation from a position where being originally printed even when a platen roller slips with respect to a printing medium, and the like.SOLUTION: A printer comprises: a first detection section 44 detecting a mark on a printing medium; a second detection section 46 being provided at a downstream side in a printing medium conveyance direction of the first detection section 44, and detecting the mark detected by the first detection section 44; a storage section 26a storing a number of logic steps corresponding to a length between the first detection section 44 and the second detection section 46; a reception section 48 receiving print data; and a control section 20 correcting positional information included in the print data based on a slip ratio calculated by the number of logic steps stored in the storage section 26a and a number of actual measurement steps obtained from a detection value of the first detection section 44 and a detection value of the second detection section 46, developing an image to be printed in a print buffer 24a based on the positional information corrected, controlling a thermal head 30, and printing the image.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a printer and a printer control method.

  Conventionally, in a printer that transports a long sheet containing a plurality of marks provided at predetermined intervals in the longitudinal direction between a print head and a platen roller, the platen roller is Due to the slip, there is a problem that printing is started before the mark included in the paper reaches the print head.

  On the other hand, it has been proposed to calculate the slip rate based on the detection values of the two mark detection sensors on the upstream side in the paper transport direction and to correct the paper transport amount to the print start position based on the slip rate. (See Patent Document 1).

JP 2002-321410 A

  However, according to Patent Document 1, although printing can be prevented before the mark included in the paper reaches the print head, the platen roller slips with respect to the paper as described above. Thus, there has been a problem that characters, graphics, and the like printed on the paper are printed out of position from which they should be printed.

  In particular, when using baggage tag paper with a relatively long length between marks and printing a plurality of characters and graphics on the paper, the characters and graphics printed on the downstream side in the paper transport direction are originally printed. The printing will be greatly deviated from the position to be printed.

  The present invention has been made in view of the above circumstances, and even if the platen roller slips with respect to the print medium, the characters and figures printed on the print medium are shifted from the positions where they should be printed. An object of the present invention is to provide a printer or the like that can suppress the occurrence of the problem.

  In order to achieve the above object, one aspect of the present invention is a printer that conveys a print medium including a plurality of marks provided at predetermined intervals between a print head and a platen roller. A first detection unit that detects a mark of the print medium, and a second detection unit that is provided downstream of the first detection unit in the print medium conveyance direction and detects the mark detected by the first detection unit; A storage unit that stores the number of logical steps corresponding to the length between the first detection unit and the second detection unit; and print data that includes position information when an image to be printed is developed in a print buffer. Based on the slip rate calculated by the receiving unit, the number of logical steps stored in the storage unit, and the actually measured number of steps obtained from the detection value of the first detection unit and the detection value of the second detection unit. The printing The position information included in the data is corrected, the image to be printed is expanded in the print buffer based on the corrected position information, and the print head is controlled on the basis of the image expanded in the print buffer. A control unit for printing.

  According to this aspect, even if the platen roller slips with respect to the printing medium, the printer that can suppress the characters, graphics, and the like printed on the printing medium from being shifted from the position where they should be printed is printed. Can be provided.

  This is based on correcting the position information included in the print data based on the slip ratio, developing the image to be printed in the print buffer based on the corrected position information, and then converting the image developed in the print buffer to Based on this, the print head is controlled to print an image.

  In the invention described above, a preferable aspect is that the first detection unit is provided on the upstream side in the print medium conveyance direction with respect to the print head, and the second detection unit is in the print medium conveyance direction with respect to the print head. Provided on the downstream side.

  According to this aspect, it is possible to detect the leading edge of the printing medium by the second detection unit and to stop the conveyance of the printing medium at the timing when the leading edge is detected. It can be prevented from being wasted.

  In the above invention, a preferred aspect is that the second detection unit detects the leading edge of the print medium.

  According to this aspect, the mark detected by the first detection unit and the leading edge of the print medium can be detected by the second detection unit.

  Further, in the above invention, a preferable aspect is that the storage unit stores the type of the print medium and the slip rate in association with each other, and the control unit, when the print medium is replaced with another print medium, With reference to the storage unit, the position information included in the print data is corrected based on the slip rate corresponding to the exchanged print medium.

  According to this aspect, even if the platen roller slips with respect to the print medium (first piece of paper), characters, graphics, and the like that are printed on the print medium (first piece of paper) should be originally printed. It is possible to suppress printing from being shifted from the position.

  In the above invention, a preferable aspect is that the position information is coordinate information including an x coordinate indicating a position in the width direction of the print medium and a y coordinate indicating a position in the transport direction of the print medium, The control unit corrects the y coordinate based on the slip rate.

  According to this aspect, even when the platen roller slips with respect to the print medium, the printer that can suppress the characters, graphics, and the like printed on the print medium from being shifted from the positions where they should be printed is prevented. Can be provided.

  This is based on the slip rate and corrects the position information (y-coordinate indicating the position in the transport direction of the print medium) included in the print data, and develops an image to be printed in the print buffer based on the corrected position information. And printing the image by controlling the print head based on the image developed in the print buffer.

  Moreover, in the said invention, a preferable aspect is provided in the printing medium conveyance direction downstream with respect to the said print head, It equips with the cutter part which cut | disconnects the said printing medium, The said control part is the said printing medium to the said cutter part. Is corrected based on the slip rate.

  According to this aspect, even if the platen roller slips with respect to the print medium, it is possible to suppress the print medium from being cut out of the original position.

  This is because the print medium can be transported to the cutting position of the cutter unit by correcting the transport amount of the print medium to the cutter unit based on the slip rate.

  In the above invention, a preferable aspect is that the print medium is roll paper.

  According to this aspect, even if the platen roller slips with respect to the roll paper, the printer that can suppress the characters, graphics, and the like printed on the roll paper from being shifted from the positions where they should be printed is printed. Can be provided.

  This is based on correcting the position information included in the print data based on the slip ratio, developing the image to be printed in the print buffer based on the corrected position information, and then converting the image developed in the print buffer to Based on this, the print head is controlled to print an image on roll paper.

  Another aspect of the present invention is a method for controlling a printer that conveys a print medium including a plurality of marks provided at predetermined intervals between a print head and a platen roller, the print medium being The mark detected by the first detection unit is detected by a first detection step of detecting the mark by the first detection unit and a second detection unit provided downstream of the first detection unit in the print medium conveyance direction. Corresponding to the length of the second detection step, the reception step of receiving print data including position information when the image to be printed is developed in the print buffer, and the length between the first detection unit and the second detection unit The position information included in the print data is calculated based on the slip rate calculated by the number of logical steps and the number of actual steps obtained from the detection value of the first detection unit and the detection value of the second detection unit. And a control step of developing the image to be printed on the print buffer based on the corrected position information and printing the image by controlling the print head based on the image developed on the print buffer. .

  According to this aspect, even if the platen roller slips with respect to the printing medium, the printer can suppress the characters and graphics printed on the printing medium from being shifted from the position where printing should be originally performed. A control method can be provided.

  This is based on correcting the position information included in the print data based on the slip ratio, developing the image to be printed in the print buffer based on the corrected position information, and then converting the image developed in the print buffer to Based on this, the print head is controlled to print an image.

1 is a diagram illustrating a schematic configuration of a printer 10 to which a printer of the present invention and a printer control method are applied. It is an example of thermal roll paper Pa. 2 is a diagram illustrating an example of a hardware configuration of a printer. FIG. 4 is a flowchart for explaining an example of the operation of the printer (printer control method). It is an example of the print image containing the image expand | deployed by the print buffer 24a based on the origin coordinate. It is an example of the print image containing the image expand | deployed by the print buffer 24a based on the corrected starting point coordinate. This is an example in which the type of thermal roll paper Pa (or identification information of an airline that uses the type of thermal roll paper Pa) and the slip rate are stored in association with each other.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each figure, corresponding components are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a diagram illustrating a schematic configuration of a printer 10 to which a printer of the present invention and a printer control method are applied.

  The printer 10 is provided at an airline service counter at an airport and issues a baggage tag. On the baggage tag, the flight number of the airplane and the name of the owner of the luggage are printed by the printer 10.

  As shown in FIG. 1, the printer 10 conveys the print medium by rotating the thermal roll paper Pa (print medium) sandwiched between the thermal head 30 (print head) and the platen roller 34 by rotating the platen roller 34. While printing in the direction, the thermal head 30 is driven to apply heat to the printing surface of the thermal roll paper Pa, and dots are formed on the printing surface of the thermal roll paper Pa to print images such as characters and figures. It is a thermal printer.

  FIG. 2 is an example of the thermal roll paper Pa.

  As shown in FIG. 2, the heat-sensitive roll paper Pa includes a plurality of marks M and a plurality of paper pieces 52 provided at predetermined intervals in the print medium conveyance direction (longitudinal direction). The marks M are, for example, a plurality of through holes provided at a predetermined interval in the width direction (short direction) of the thermal roll paper Pa.

  FIG. 3 is a diagram illustrating an example of a hardware configuration of the printer 10.

  As shown in FIG. 3, the printer 10 includes a control unit 20, a thermal head 30, a head drive circuit 32 connected to the thermal head 30, a platen roller 34, a transport motor 36, and a cutter unit 38 (cutter unit) as hardware configurations. , Cutter drive motor 40, transport motor 36, motor drive circuit 42 connected to cutter drive motor 40, first sensor 44 (first detection unit), second sensor 46 (second detection unit), communication I / F 48 ( Receiving section).

  The head drive circuit 32, the motor drive circuit 42, the first sensor 44, the second sensor 46, and the communication I / F 48 are connected to the control unit 20.

  The control unit 20 includes a CPU 22, a RAM 24, a ROM 26 (storage unit), and the like. The RAM 24 includes a print buffer 24a. The ROM 26 is a rewritable nonvolatile memory such as a flash ROM, for example, and stores firmware such as a control program. The ROM 26 includes a logical step number storage unit 26a and a slip rate storage unit 26b.

  The logical step number storage unit 26 a stores a logical step number corresponding to the length between the first sensor 44 and the second sensor 46. As shown in FIG. 1, the length between the first sensor 44 and the second sensor 46 is between the detection position P1 of the mark M by the first sensor 44 and the detection position P2 of the mark M by the second sensor 46. Distance L. Assuming that the platen roller 34 does not slip, the number of logical steps corresponding to the length between the first sensor 44 and the second sensor 46 is the same as the thermal roll paper Pa (mark M). This is the number of steps of the transport motor 36 required for transport from the detection position P1 to the detection position P2 of the second sensor 46. The number of logical steps is measured, for example, at the manufacturing stage of the printer 10 and stored in advance in the logical step number storage unit 26a.

  The slip rate storage unit 26b stores a slip rate calculated as described later.

  The thermal head 30 is driven by a head drive circuit 32 connected thereto. When the control unit 20 controls the head driving circuit 32 to drive the thermal head 30, the thermal head 30 applies heat to the printing surface of the thermal roll paper Pa to form dots on the printing surface of the thermal roll paper Pa. As a result, images such as characters and graphics are printed on the printing surface of the thermal roll paper Pa.

  The platen roller 34 is connected to the transport motor 36 via a transmission mechanism (not shown) (for example, a reduction gear train). The transport motor 36 is, for example, a stepping motor. The transport motor 36 is driven by a motor drive circuit 42 connected thereto. When the control unit 20 controls the motor drive circuit 42 to drive the transport motor 36, the rotation of the transport motor 36 is transmitted to the platen roller 34 through the transmission mechanism, and the platen roller 34 rotates. As a result, the thermal roll paper Pa sandwiched between the thermal head 30 and the platen roller 34 is conveyed in the print medium conveyance direction (see FIG. 1).

  The first sensor 44 is a detection unit that detects the mark M on the thermal roll paper Pa, and is configured by a transmissive optical sensor such as a transmissive photo interrupter, for example. The first sensor 44 is provided upstream of the thermal head 30 in the print medium conveyance direction. The control unit 20 detects the mark M on the thermal roll paper Pa based on the change in the detection value of the first sensor 44 when the mark M on the thermal roll paper Pa passes the detection position P1 of the first sensor 44.

  The second sensor 46 is a detection unit that detects the mark M of the thermal roll paper Pa (the same mark M detected by the first sensor 44) and the leading end of the thermal roll paper Pa. For example, a transmissive photo interrupter or the like. The transmission type optical sensor. The second sensor 46 is provided, for example, downstream of the thermal head 30 in the print medium conveyance direction. Based on the change in the detection value of the second sensor 46 when the mark M passes the detection position P2 of the second sensor 46, the control unit 20 The mark M of the thermal roll paper Pa is detected.

  The cutter unit 38 includes a cutter driving mechanism (not shown) that linearly moves the movable blade 38a with respect to the fixed blade 38b (in the vertical direction in FIG. 1). Provided downstream in the transport direction. The cutter driving mechanism includes a cutter driving motor 40. The cutter drive motor 40 is driven by a motor drive circuit 42 connected thereto. When the control unit 20 controls the motor drive circuit 42 to drive the cutter drive motor 40, the movable blade 38a is linearly moved in a direction approaching the fixed blade 38b. Thereby, the thermal roll paper Pa located in the cutting position P3 (refer FIG. 1) of the cutter unit 38 is cut | disconnected.

  A host computer 50 is connected to the communication I / F 48 via a communication cable or the like. The communication I / F 48 functions as a receiving unit that receives print data transmitted from the host computer 50. The print data is data for printing images such as characters and graphics on the thermal roll paper Pa, and includes position information when the image to be printed is developed in the print buffer 24a. The position information includes an x coordinate indicating a position in the width direction (x-axis direction in FIG. 5) of the thermal roll paper Pa and a y coordinate indicating a position in the transport direction (y-axis direction in FIG. 5) of the thermal roll paper Pa. The coordinate information included serves as a starting point when an image to be printed is developed in the print buffer 24a. Hereinafter, the position information is referred to as a starting point coordinate.

  Next, an example of the operation of the printer 10 (printer control method) will be described with reference to the drawings.

  FIG. 4 is a flowchart for explaining an example of the operation of the printer 10 (printer control method).

  The following processing is realized mainly by executing the firmware read from the ROM 26 by the control unit 20.

  First, the control unit 20 controls the motor drive circuit 42 to drive the transport motor 36 and rotate the platen roller 34, so that the thermal roll paper Pa sandwiched between the thermal head 30 and the platen roller 34 is removed. Then, it is conveyed in the print medium conveyance direction (step S10).

  Next, the control unit 20 determines whether or not the leading edge of the thermal roll paper Pa is detected based on the detection result of the second sensor 46 (step S12).

  When it determines with the control part 20 having detected the front-end | tip of the thermal roll paper Pa (step S12: Yes), the conveyance of the thermal roll paper Pa is controlled by controlling the motor drive circuit 42 and stopping the drive of the conveyance motor 36. Is stopped (step S14).

  Next, the communication I / F 48 receives print data transmitted from the host computer 50 for printing on the first piece of paper 52 (step S16). This corresponds to the reception process of the present invention.

  Next, the control unit 20 determines whether or not there is a slip rate, specifically, whether or not the slip rate is stored in the slip rate storage unit 26b (step S18).

  Here, since the slip rate is not stored in the slip rate storage unit 26b, the control unit 20 determines that the slip rate is not stored in the slip rate storage unit 26b (step S18: No).

  When it is determined that the slip rate is not stored in the slip rate storage unit 26b (step S18: No), the control unit 20 includes a print image including images such as characters and graphics based on the print data received from the host computer 50. Is expanded in the print buffer 24a (step S20). At that time, as shown in FIG. 5, the control unit 20 develops a print image including an image such as a character or a graphic in the print buffer 24a based on the starting point coordinates included in the print data. FIG. 5 is an example of a print image including an image developed in the print buffer 24a based on the starting point coordinates.

  In FIG. 5, a symbol D1 represents an image developed in the print buffer 24a based on the starting point coordinates (x1, y1), and a symbol D2 is developed in the print buffer 24a based on the starting point coordinates (x2, y2). Represents an image. Symbol S1 represents an area corresponding to the print area of the thermal roll paper Pa, and the position (x0, y0) represents the origin of the xy coordinate system. In FIG. 5, the x-axis extends in the width direction of the thermal roll paper Pa, and the y-axis extends in the conveyance direction of the thermal roll paper Pa.

  Next, the control unit 20 controls the thermal head 30 and the like based on the image (print image) developed in the print buffer 24a, and heats images such as characters and figures (for example, images D1 and D2 shown in FIG. 5). Printing on the roll paper Pa (step S22). This corresponds to the printing process of the present invention. At that time, the control unit 20 controls the motor drive circuit 42 to drive the transport motor 36 and reversely rotate the platen roller 34 in order to adjust the print start position, whereby the thermal head 30 and the platen roller 34 are rotated. The thermal roll paper Pa sandwiched between them is transported by a predetermined amount in the direction opposite to the print medium transport direction. Thereafter, the control unit 20 rotates the platen roller 34 in the forward direction, thereby conveying the thermal roll paper Pa sandwiched between the thermal head 30 and the platen roller 34 in the printing medium conveyance direction and continuing the printing operation. .

  Next, the control unit 20 determines whether or not the mark M of the thermal roll paper Pa is detected based on the detection result of the first sensor 44 (step S24). This corresponds to the first detection step of the present invention.

  When it is determined that the mark M of the thermal roll paper Pa is detected (step S24: Yes), the control unit 20 controls the motor drive circuit 42 to drive the transport motor 36 and rotate the platen roller 34. The thermal roll paper Pa (mark M) is transported to the cutting position P3 of the cutter unit 38 (step S26). Specifically, the control unit 20 rotates the transport motor 36 by the number of steps necessary to transport the thermal roll paper Pa (mark M) from the detection position P1 of the first sensor 44 to the cutting position P3 of the cutter unit 38. In this manner, the motor drive circuit 42 is controlled to drive the transport motor 36.

  Further, when it is determined that the mark M of the thermal roll paper Pa is detected (step S24: Yes), the control unit 20 starts counting the number of steps of the transport motor 36.

  Next, the control unit 20 determines based on the detection result of the second sensor 46 whether or not the mark M of the thermal roll paper Pa (the same mark M as detected by the first sensor 44) has been detected (step). S28). This corresponds to the second detection step of the present invention.

  When it is determined that the mark M on the thermal roll paper Pa is detected (step S28: Yes), the control unit 20 finishes counting the number of steps of the transport motor 36, and stores the counted number of steps in a storage unit such as the ROM 26. Remember. The counted number of steps represents the actually measured number of steps of the transport motor 36 required to transport the thermal roll paper Pa (mark M) from the detection position P1 of the first sensor 44 to the detection position P2 of the second sensor 46.

  Next, the control unit 20 calculates the slip rate based on the number of logical steps stored in the logical step number storage unit 26a and the actually measured number of steps stored in the storage unit such as the ROM 26 (step S30). The rate is stored in the slip rate storage unit 26b (step S32). The slip rate is calculated by the following formula. Note that the slip ratio is calculated during printing on the first piece of paper 52.

Slip rate = Number of actually measured steps / Number of logical steps (Equation 1)
For example, when the number of actually measured steps is 110 and the number of logical steps is 100, the slip ratio = 110/100 = 1.1 is calculated.

  Next, the control unit 20 controls the motor driving circuit 42 to drive the cutter driving motor 40, and the cutter unit 38 cuts the thermal roll paper Pa after printing located at the cutting position P3 of the cutter unit 38 ( Step S34). This cut piece of paper 52 is used as a baggage tag.

  Next, the communication I / F 48 receives print data transmitted from the host computer 50 for printing on the second piece of paper 52 (step S16). This corresponds to the reception process of the present invention.

  Next, the control unit 20 determines whether or not there is a slip rate, specifically, whether or not the slip rate is stored in the slip rate storage unit 26b (step S18).

  Here, since the slip rate is stored in the slip rate storage unit 26b in step S32, the control unit 20 determines that the slip rate is stored in the slip rate storage unit 26b (step S18: Yes).

  When it is determined that the slip rate is stored in the slip rate storage unit 26b (step S18: Yes), the control unit 20 starts the coordinates included in the print data based on the slip rate stored in the slip rate storage unit 26b. Among them, the y coordinate is corrected (step S36). Specifically, correction is performed by multiplying the y coordinate of the starting point coordinates included in the print data by the slip rate stored in the slip rate storage unit 26b.

  For example, in the example shown in FIG. 5, the starting point coordinates (x1, y1) are corrected as (x1, y1 × slip rate), and the starting point coordinates (x2, y2) are corrected as (x2, y2 × slip rate).

  Next, the control unit 20 develops a print image including images such as characters and graphics on the print buffer 24a based on the print data received from the host computer 50 (step S20). At that time, as shown in FIG. 6, the control unit 20 develops a print image including an image such as a character or a graphic in the print buffer 24a based on the starting point coordinates corrected as described above. This corresponds to the development process of the present invention. FIG. 6 is an example of a print image including an image developed in the print buffer 24a based on the corrected starting point coordinates.

  In FIG. 6, reference numeral D1 represents an image developed in the print buffer 24a based on the corrected starting point coordinates (x1, y1 × slip rate), and reference numeral D2 represents the corrected starting point coordinates (x2, y2 × slip rate). Represents the image developed in 24a in the print buffer.

  Next, the control unit 20 controls the thermal head 30 and the like based on the image (printed image) developed in the print buffer 24a to heat images such as characters and figures (for example, images D1 and D2 shown in FIG. 6). Printing on the roll paper Pa (step S22). This corresponds to the control process of the present invention. At that time, the control unit 20 controls the motor drive circuit 42 to drive the transport motor 36 and reversely rotate the platen roller 34 in order to adjust the print start position, whereby the thermal head 30 and the platen roller 34 are rotated. The thermal roll paper Pa sandwiched between them is transported by a predetermined amount in the direction opposite to the print medium transport direction. Thereafter, the control unit 20 rotates the platen roller 34 in the forward direction, thereby conveying the thermal roll paper Pa sandwiched between the thermal head 30 and the platen roller 34 in the printing medium conveyance direction and continuing the printing operation. .

  Thereafter, similarly to the above, Steps S24 to S34 are executed, and the thermal roll paper Pa (mark M) is conveyed to the cutting position P3 of the cutter unit 38, and the cutting position P3 of the cutter unit 38 is cut by the cutter unit 38. The heat-sensitive roll paper Pa after printing located in is cut. This cut piece of paper 52 is used as a baggage tag. The third and subsequent paper pieces 52 can be printed in the same manner as described above.

  As described above, according to the present embodiment, even if the platen roller 34 slips with respect to the thermal roll paper Pa, images such as characters and figures printed on the thermal roll paper Pa should be originally printed. It is possible to provide a printer 10 and a printer control method that can suppress printing from being displaced from the position.

  This is based on the corrected starting point coordinates by correcting the starting point coordinates (y coordinate indicating the position in the transport direction of the print medium) included in the print data based on the sliding ratios stored in the sliding rate storage unit 26b. This is because the image to be printed is developed in the print buffer 24a, and the thermal head 30 is controlled based on the image developed in the print buffer 24a to print the image on the thermal roll paper Pa.

  Further, according to the present embodiment, it is possible to detect the leading edge of the thermal roll paper Pa by the second sensor 46 and to stop the conveyance of the thermal roll paper Pa at the timing when the leading edge is detected. The first piece of paper 52 can be prevented from being wasted.

  Further, according to the present embodiment, the second sensor 46 can detect the same mark M detected by the first sensor 44 and the leading edge of the thermal roll paper Pa.

  Next, a modified example will be described.

  In the above embodiment, the description has been made such that the starting point coordinates are corrected when printing on the second and subsequent paper pieces 52, but the present invention is not limited to this. For example, before printing on the first piece of paper 52, the slip rate may be stored in the slip rate storage unit 26b. For example, the slip rate stored when the printer 10 was used last time is left without being erased, and the origin coordinate is corrected using the slip rate when printing on the first piece of paper 52 this time. Good.

  The slip rate may be stored in the slip rate storage unit 26b before printing on the first piece of paper 52 as follows.

  For example, it is assumed that the airline a and the airline b jointly use the printer 10, and the airline b uses the printer 10, so the thermal roll paper Pa (type A) set by the airline a is used. Is replaced with another type of thermal roll paper Pa (type B). In the storage unit such as the ROM 26, as shown in FIG. 7, the type of thermal roll paper Pa (or identification information of an airline that uses the thermal roll paper Pa of that type) is associated with the slip rate in advance. It shall be remembered.

  In this case, before step S10 shown in FIG. 4, the type B of the thermal roll paper Pa after replacement (or the identification information of the airline b that uses the thermal roll paper Pa of the type B) is obtained from the host computer 50 or the like. Input, referring to the storage unit such as the ROM 26 and the like, is associated with the input type B of the thermal paper roll Pa after replacement (or identification information of the airline b using the type B thermal paper Pa). The sliding rate is read from the storage unit such as the ROM 26 and stored in the sliding rate storage unit 26b.

  As described above, the slip rate can be stored in the slip rate storage unit 26b before printing on the first piece of paper 52.

  According to this modification, even if the platen roller 34 slips with respect to the first paper piece 52, characters, graphics, etc. printed on the first paper piece 52 are shifted from the positions where they should be printed. It is possible to suppress printing.

  In the above-described embodiment, the description has been made so that the step S30 for calculating the slip rate is executed every time the paper piece 52 is printed. However, the present invention is not limited to this. For example, step S30 for calculating the slip rate when printing on the first piece of paper 52 may be executed, and step S30 for calculating the slip rate when printing on the subsequent piece of paper 52 may not be executed. It should be noted that the accuracy of correction can be further increased by executing step S30 for calculating the slip ratio each time printing is performed on the piece of paper 52.

  In the above embodiment, an example in which the first sensor 44 is provided upstream of the thermal head 30 in the print medium conveyance direction and the second sensor 46 is provided downstream of the thermal head 30 in the print medium conveyance direction will be described. However, it is not limited to this.

  That is, it is only necessary that the second sensor 46 is provided downstream of the first sensor 44 in the print medium conveyance direction. For example, both the first sensor 44 and the second sensor 46 print on the thermal head 30. It may be provided on the upstream side in the medium conveyance direction, or may be provided on the downstream side in the print medium conveyance direction with respect to the thermal head 30.

  Further, in the above embodiment, the control unit 20 includes the number of steps necessary to transport the thermal roll paper Pa (mark M) from the detection position P1 of the first sensor 44 to the cutting position P3 of the cutter unit 38, and the transport motor 36. In the above description, the motor driving circuit 42 is controlled so as to drive the transport motor 36 so as to rotate, but the present invention is not limited thereto.

  For example, the control unit 20 calculates the number of steps (print medium conveyance amount) necessary to convey the thermal roll paper Pa (mark M) from the detection position P1 of the first sensor 44 to the cutting position P3 of the cutter unit 38. Correction may be performed based on the slip rate stored in the slip rate storage unit 26b, and the transport motor 36 may be driven by controlling the motor drive circuit 42 so that the transport motor 36 rotates by the number of steps after the correction. Good. The correction based on the slip rate is performed by adding the slip rate storage unit to the number of steps necessary to transport the thermal roll paper Pa (mark M) from the detection position P1 of the first sensor 44 to the cutting position P3 of the cutter unit 38. The correction is to multiply the slip rate stored in 26b.

  In this way, even if the platen roller 34 slips with respect to the thermal roll paper Pa (printing medium), the position where the thermal roll paper Pa (mark M) should be cut, that is, the cutting position of the cutter unit 38. It can suppress that it shifts | deviates from P3 and is cut | disconnected.

  This corrects the conveyance amount of the thermal roll paper Pa to the cutter unit 38 (cutter part) based on the slip rate, thereby conveying the thermal roll paper Pa (mark M) to the cutting position P3 of the cutter unit 38. It is because it can be.

  In the above-described embodiment, an example in which the heat-sensitive roll paper Pa is used as the print medium has been described. However, the present invention is not limited to this, and other paper may of course be used.

  All the numerical values shown in the above embodiment are exemplifications, and it is needless to say that appropriate numerical values different from these can be used.

  The said embodiment is only an illustration in all the points, and this invention is not interpreted limitedly by description of the said embodiment. The present invention can be implemented in various other forms without departing from the spirit or main features thereof.

  DESCRIPTION OF SYMBOLS 10 ... Printer, 20 ... Control part, 22 ... CPU, 24 ... RAM, 24a ... Print buffer, 26 ... ROM, 26a ... Logic step number memory | storage part, 26b ... Sliding rate memory | storage part, 30 ... Thermal head, 32 ... Head drive Circuit 34 ... Platen roller 36 ... Conveyance motor 38 ... Cutter unit 38a ... Movable blade 38b ... Fixed blade 40 ... Cutter drive motor 42 ... Motor drive circuit 44 ... First sensor 46 ... Second sensor 48 ... Communication I / F, 50 ... Host computer, 52 ... Paper, A, B ... Type, D1, D2 ... Image, L ... Distance, M ... Mark, P1, P2 ... Detection position, P3 ... Cut position, Pa ... thermal roll paper, a, b ... airline.

Claims (8)

A printer that conveys a print medium including a plurality of marks provided at predetermined intervals between a print head and a platen roller,
A first detector for detecting a mark on the print medium;
A second detection unit that is provided downstream of the first detection unit in the print medium conveyance direction and detects a mark detected by the first detection unit;
A storage unit that stores the number of logical steps corresponding to the length between the first detection unit and the second detection unit;
A receiving unit that receives print data including position information when an image to be printed is developed in a print buffer;
Based on the slip rate calculated by the number of logical steps stored in the storage unit and the actual number of steps obtained from the detection value of the first detection unit and the detection value of the second detection unit, the print data is added to the print data. Control for correcting the position information included, expanding the image to be printed in the print buffer based on the corrected position information, and controlling the print head based on the image expanded in the print buffer to print the image A printer. The first detection unit is provided on the upstream side in the print medium conveyance direction with respect to the print head,
The printer according to claim 1, wherein the second detection unit is provided on the downstream side in the print medium conveyance direction with respect to the print head.   The printer according to claim 2, wherein the second detection unit detects a leading edge of the print medium. The storage unit stores the type of the print medium and the slip rate in association with each other,
The controller is
When the print medium is replaced with another print medium, the storage unit is referred to correct position information included in the print data based on a slip rate corresponding to the replaced print medium. Item 4. The printer according to any one of Items 1 to 3. The position information is coordinate information including an x coordinate indicating a position in the width direction of the print medium and a y coordinate indicating a position in the transport direction of the print medium,
The controller is
The printer according to claim 1, wherein the y coordinate is corrected based on the slip ratio. Provided on the downstream side in the print medium conveyance direction with respect to the print head, comprising a cutter unit for cutting the print medium,
The controller is
The printer according to claim 1, wherein the conveyance amount of the print medium to the cutter unit is corrected based on the slip rate.   The printer according to claim 1, wherein the print medium is roll paper. A control method for a printer that conveys a print medium including a plurality of marks provided at a predetermined interval, sandwiched between a print head and a platen roller,
A first detection step of detecting a mark on the print medium by a first detection unit;
A second detection step of detecting a mark detected by the first detection unit by a second detection unit provided downstream of the first detection unit in the print medium conveyance direction;
A receiving step for receiving print data including position information when an image to be printed is developed in a print buffer;
The number of logical steps corresponding to the length between the first detection unit and the second detection unit, the number of actual measurement steps obtained from the detection value of the first detection unit and the detection value of the second detection unit, The position information included in the print data is corrected based on the slip rate calculated by the above, the image to be printed is developed in the print buffer based on the corrected position information, and the image developed in the print buffer And a control step of controlling the print head to print an image.

Images