JP2014084221A - Automatic position detection method and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic position detection method for detecting a position of a printing medium dispensing with an operation for making a user move a sensor unit, and a printer.SOLUTION: An automatic position detection method includes: a step S104 of measuring the width of a printing medium 4 by movement of a sensor unit 20; a step S106 of carrying the printing medium 4 along a transfer passage when the width of the printing medium 4 is measured; a step S108 of detecting a pitch mark in an area for detecting the pitch mark; and a step S112 of stopping carrying of the printing medium 4 when the pitch mark is detected.

Description

  The present invention relates to an automatic position detection method and printer for detecting the position of a label continuum as a print medium, and more particularly to an automatic position detection method and printer for detecting the position of a pitch mark of a label continuum.

  In a conventional printer that prints on a label continuum as a print medium, if the label continuum used has a pitch mark printed on the back side of the strip or a hole on the strip as a pitch mark, By detecting the pitch mark with a reflective sensor or a transmissive sensor, the leading edge of each label is recognized and the printing timing is controlled.

  Since the reflective sensor and the transmissive sensor have different label widths and label shapes depending on the print medium used, the reflective sensor and the transmissive sensor are configured to be movable in the width direction of the print medium. Aligned to the appropriate position of the gap. As a moving mechanism for moving the reflective sensor and the transmissive sensor in the width direction of the print medium, for example, as shown in Patent Document 1, the light emitting element and the light receiving element of the transmissive sensor are moved up and down the transfer path of the print medium. Therefore, the reflective sensor and the transmissive sensor are attached to the U-shaped unit between which the print medium transfer path is formed so that the unit itself can move in the width direction of the print medium. It is configured.

JP-A-11-199097

  However, according to the conventional technology, the unit itself to which the reflection type sensor or the transmission type sensor is attached is configured to be movable in the width direction of the print medium. However, there has been a problem that the space becomes larger than necessary, the space for storing the drive mechanism, the control board, etc. is restricted or the design becomes complicated. Further, in the prior art, it is necessary for the user to manually move the unit to which the reflective sensor and the transmissive sensor are attached to adjust the reflective sensor and the transmissive sensor to the pitch mark position of the print medium. Further, in a unit that is manually moved depending on the position or type of the pitch mark formed on the print medium, the print medium pitch mark may be formed in an undetectable area, and another sensor is placed in that area. It is provided in the transfer path.

  The present invention has been made in view of such circumstances, and prints the reflective sensor and the transmissive sensor without moving the sensor unit itself that moves the reflective sensor and the transmissive sensor in the width direction of the print medium. Provided are an automatic position detection method and a printer that can move in the width direction of a medium and automatically detect the front end of a print medium that does not require user operation by a printer that does not require a movement space of the sensor unit itself. The purpose is to do. It is another object of the present invention to provide an automatic position detection method and a printer that improve the workability of maintenance because a plurality of transmissive sensors are not arranged.

In order to achieve the above object, an automatic position detection method according to the present invention comprises a sensor carriage provided with an optical sensor for detecting the print medium while transferring the print medium along a transfer path, and the sensor carriage. An automatic position detection method for detecting a pitch mark of the print medium with a sensor unit provided so as to move by driving a belt, and measuring the width of the print medium by moving the sensor unit; When the width of the print medium is measured, the step of conveying the print medium along the transfer path, the step of moving the sensor unit to a preset position, the step of detecting the pitch mark, and the pitch mark And a step of stopping the conveyance of the print medium when detected.
In order to achieve the above object, the printer according to the present invention includes a printing unit that prints while holding and conveying the print medium along a transfer path by a print head and a platen roller that is rotationally driven, and detects the print medium. A sensor carriage provided with an optical sensor, a sensor unit provided to move the sensor carriage by driving a belt, and the width of the print medium is measured by the movement of the sensor unit. Then, the platen roller of the printing unit is rotated to convey the printing medium, the pitch mark is detected in the area where the pitch mark is detected, and when the pitch mark is detected, the platen roller of the printing unit is stopped. And a control unit that controls to stop the conveyance of the print medium.
According to the aspect of the automatic position detection method of the present invention, the sensor carriage includes an upper sensor carriage provided with one element of the transmissive sensor for detecting the print medium, and the other element of the transmissive sensor. A lower sensor carriage provided, and positioned so that one element of the transmissive sensor and the other element face each other, and the upper sensor carriage and the lower sensor carriage are moved synchronously by driving a belt. Is preferred.
According to the aspect of the automatic position detection method of the present invention, a reflection type sensor is provided in any one of the sensor carriages, and the transmission type sensor or the reflection type is selected according to a pitch mark provided on the print medium. It is preferable to have a step of determining which of the sensors to use and a region to be sensed by the transmissive sensor or the reflective sensor.
According to the aspect of the automatic position detection method of the present invention, it is detected whether or not the transmission type sensor and the reflection type sensor of the sensor unit are at the origin position, and if they are not at the origin position, they are moved to the origin position. Preferably comprising steps.
According to the aspect of the automatic position detection method of the present invention, in the step of detecting whether or not the transmission type sensor and the reflection type sensor of the sensor unit are at the origin position, the sensor unit is formed long in the transport direction of the print medium. It is preferable to detect whether or not the transmission type sensor and the reflection type sensor of the sensor unit are at the origin position by an origin detection plate provided with a long hole.
Furthermore, according to the aspect of the automatic position detection method of the present invention, the belt is wound around a plurality of pulleys so as to drive up and down the print medium perpendicular to the print medium transfer path. It is preferable to use an endless belt.

  According to the automatic position detection method of the present invention, the reflective sensor and the transmissive sensor can be moved in the width direction of the print medium without moving the sensor unit itself, and the movement space of the sensor unit itself is ensured. There is no need. And the operation which moves a sensor unit by a user becomes unnecessary.

1 is a schematic side view illustrating a configuration of an embodiment of a printer according to the present invention. It is a figure which shows an example of the printing medium shown in FIG. It is a schematic perspective view which shows arrangement | positioning of the sensor unit provided with the reflection type sensor and transmission type sensor which are shown in FIG. It is a front view which shows the structure of the sensor unit shown in FIG. It is a schematic perspective view which shows arrangement | positioning of the sensor unit shown in FIG. It is a flowchart showing the automatic position detection method of this invention. It is a front view which shows the structure of the other sensor unit concerning this invention. It is a front view which shows the structure of the other sensor unit concerning this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic side view showing a configuration of an embodiment of a sensor unit and a printer according to the present invention, and FIG. 2 is a diagram showing a configuration of a print medium shown in FIG.

  Referring to FIG. 1, the printer 1 of the present embodiment includes a platen roller 2 and a thermal head 3 in which a heating element is formed on a surface facing the platen roller 2. The print medium 4 on which a plurality of labels are temporarily attached to a belt-like mount and the ink ribbon 5 are overlapped and sandwiched between the platen roller 2 and the thermal head 3 to selectively heat the heating element of the thermal head 3. Thus, the ink is transferred from the ink ribbon 5 onto the printing surface of the label to print a desired character, barcode or the like.

  The print medium 4 is rotatably supported by the paper supply unit 6 while being wound in a roll shape, and is supplied from the paper supply unit 6 between the platen roller 2 and the thermal head 3. Further, the ink ribbon 5 is bridged between the ribbon supply unit 7 and the ribbon winding unit 8. The ink ribbon 5 supported while being wound around the ribbon supply unit 7 in a roll shape is supplied between the platen roller 2 and the thermal head 3, and the transferred ink ribbon 5 is transferred by the ribbon take-up unit 8. It is wound up.

  As the print medium 4 used in the printer 1 of the present embodiment, as shown in FIG. 2A, a black mark 4a is formed by printing or the like as a pitch mark indicating the tip position to be printed on the back side. There is a label continuum 4x. In this example, a label 4 ′ is temporarily attached at a predetermined pitch on the surface side of the print medium 4, and black marks 4 a are printed at the same pitch as the label 4 ′. Further, as the print medium 4 used in the printer 1 of the present embodiment, as shown in FIG. 2 (b), holes 4b are formed at a predetermined pitch in the center in the width direction of the strip-shaped continuous tag body 4y made of cardboard. What is being used may be used. Furthermore, as shown in FIG. 2C, the print medium 4 used in the printer 1 of the present embodiment has holes 4c at a predetermined pitch at the end in the width direction of the strip-shaped tag continuous body 4z made of cardboard. What is formed may be used.

  A reflective sensor that detects a black mark (pitch mark) 4a formed on the back side of the print medium 4 and outputs a pitch mark detection signal in the transfer path of the print medium 4 from the paper supply unit 6 to the print position. 9 and a transmissive sensor 10 that detects the position of a hole (pitch mark) 4b formed in the print medium 4 and outputs a gap signal. The pitch mark detection signal or the gap signal is input to the control unit 11, and the control unit 11 calculates the label leading end position based on the pitch mark detection signal or the gap signal to rotationally drive the thermal head 3 and the platen roller 2. Printing is performed by controlling a drive motor (not shown). The controller 11 recognizes the position of the label or tag by the pitch mark detection signal or the gap signal, thereby controlling the thermal head 3 and a driving motor (not shown) that rotationally drives the platen roller 2 to perform printing.

  3-5 is a figure which shows an example of a structure of embodiment of a sensor unit, FIG. 3 and FIG. 5 is a perspective view, FIG. 4 is a front view.

  As shown in FIGS. 3 and 4, the sensor unit 20 has one endless belt for each of the plurality of pulleys 24 a to 24 e so as to drive the top and bottom of the print medium 4 perpendicular to the transfer direction of the transfer path of the print medium 4. (Timing belt) 22 is wound around. As shown in FIG. 4, the pulley 24 a and the pulley 24 b are below the transfer path of the print medium 4, the pulley 24 c and the pulley 24 d are above the transfer path of the print medium 4, and the pulley 24 e is the print medium 4. The endless belt 22 is wound around the pulley 24a, the pulley 24b, the pulley 24c, the pulley 24d, the pulley 24e, and the pulley 24a. Of the plurality of pulleys 24a to 24e, the pulley 24e is provided with a gear 26. The gear 26 meshes with the gear 28a of the driving means 28, and the pulley 24e is rotated by driving the driving means 28 to rotate the pulley 24e. The endless belt 22 is driven. The plurality of pulleys 24 a to 24 d are driven to rotate as the endless belt 22 is driven. Here, it is preferable to use a stepping motor as the driving means 28.

  In FIG. 4, when the pulley 24e provided with the gear 26 rotates clockwise, the endless belt 22 is driven between the endless belt 22d between the pulley 24c and the pulley 24d and between the pulley 24a and the pulley 24e. The endless belt 22b is driven leftward, and the endless belt 22c between the pulley 24d and the pulley 24e and the endless belt 22a between the pulley 24a and the pulley 24b are driven rightward. Conversely, when the pulley 24e provided with the gear 26 rotates counterclockwise, the endless belt 22d between the pulley 24c and the pulley 24d and the endless belt 22b between the pulley 24a and the pulley 24e are moved in the right direction. The endless belt 22c between the pulley 24d and the pulley 24e and the endless belt 22a between the pulley 24a and the pulley 24b are driven in the left direction.

  The sensor unit 20 is provided with an upper sensor carriage 30 a provided with the light receiving element 10 a of the transmissive sensor 10, a reflective sensor 9, a light emitting element 10 b of the transmissive sensor 10, and a light receiving element 9 a of the reflective sensor 9. The lower sensor carriage 30 b is provided on one endless belt 22.

  The upper sensor carriage 30a and the lower sensor carriage 30b are arranged so that at least the light receiving element 10a and the light emitting element 10b of the transmissive sensor 10 face each other. 3 to 5, the upper sensor carriage 30a is provided on the endless belt 22d between the pulley 24c and the pulley 24d, and the lower sensor carriage 30b is provided on the endless belt 22b between the pulley 24a and the pulley 24e. Yes. Thus, when the upper sensor carriage 30a and the lower sensor carriage 30b drive the driving means 28 and rotate the pulley 24e, the upper sensor carriage 30a and the lower sensor carriage 30b face each other in the transfer path of the print medium 4. It is moved in the width direction. Accordingly, the light receiving element 10a of the upper sensor carriage 30a and the light emitting element 10b of the lower sensor carriage 32 are moved in synchronism with each other without deviation.

  3 to 5, the upper sensor carriage 30a is provided on the endless belt 22d and the lower sensor carriage 30b is provided on the endless belt 22b. However, the upper sensor carriage 30a is provided between the pulley 24d and the pulley 24e. Even if the endless belt 22c and the lower sensor carriage 30b are provided on the endless belt 22a between the pulley 24a and the pulley 24b, the upper sensor carriage 30a and the lower sensor carriage 30b face each other in the transfer path of the print medium 4. It is moved in the width direction. The light receiving element 10a provided on the upper sensor carriage 30a, and the light emitting element 10b and light receiving element 9a provided on the lower sensor carriage 32 can be arranged so as to extend in the conveyance direction of the print medium so as not to be blocked by the belt.

  In this way, the sensor unit 20 itself is moved in the width direction of the print medium 4 in a state where the upper sensor carriage 30a and the lower sensor carriage 30b are opposed to each other by the single endless belt 22. Since the transmission type sensor 10 can be moved in the width direction of the print medium 4 without being moved in the width direction, there is an effect that it is not necessary to secure a movement space for the sensor unit 20 itself.

  In the present embodiment, the sensor unit 20 can be provided with a pair of guide plates (not shown) for guiding the upper surface side and the lower surface side of the print medium. The pair of guide plates includes an upper guide (not shown) for guiding the upper surface side of the print medium and a lower guide (not shown) for guiding the lower surface side of the print medium. The print medium of the upper sensor carriage 30a and the lower sensor carriage 30b. It can arrange | position along a transfer path toward the downstream from the upstream of the conveyance direction.

  In this embodiment, as shown in FIG. 1, the print medium sensor unit is provided at the position where the print medium is inclined, but the sensor unit is provided in the transfer path for transferring the print medium in the horizontal direction. be able to.

  In this embodiment, as shown in FIG. 5, two shafts 34a and 34b are disposed along the endless belt, and the upper sensor carriage 30a and the lower sensor carriage 30b are further supported by the shafts 34a and 34b, respectively. It is preferable to be configured to slide along the shaft by driving the endless belt.

  Since the upper sensor carriage 30a and the lower sensor carriage 30b are respectively supported by the shafts 34a and 34b, the reflective sensor and the transmissive sensor can be moved more stably in the width direction of the print medium.

  In the present embodiment, as shown in FIGS. 3 and 4, it is preferable that an origin detection plate 36 provided with a long hole 38 formed long in the transport direction of the print medium 4 is provided. The origin detection plate 36 is provided at an extended position of the transfer path of the print medium 4 and is positioned between the pulley 24 e and the transfer path of the print medium 4.

  An automatic position detection method for detecting the position of the print medium in the printer configured as described above will be described.

  As shown in FIG. 6, first, in S100, it is detected whether or not the transmission type sensor 10 and the reflection type sensor 9 of the sensor unit 20 are at the origin position, and if they are not at the origin position, they are moved to the origin position.

  Next, in S102 of FIG. 6, the operator confirms the pitch mark provided on the print medium 4 and selects whether to use the transmissive sensor 10 or the reflective sensor 9 in the control unit 11. In this case, it is selected whether the print medium 4 is a label continuous body or a tag.

  In addition, when the label continuous body is selected, it is stored in advance in the control unit 11 so as to move the transmission sensor 10 to the center position in the width direction of the print medium. When the tag is selected, the control unit 11 stores in advance that the transmission sensor 10 reciprocates at the maximum width (area) of the print medium to detect the hole. When the reflective sensor 9 is selected, it is stored in the control unit 11 in advance so as to move a predetermined distance from the one side (origin detection plate 36 side) of the print medium 4 toward the center in the width direction. deep.

  In S104, the width of the print medium 4 is measured by the sensor unit 20 for the print medium 4 being conveyed.

  Specifically, the drive means is driven to move the sensor carriages 30 a and 30 b toward the origin detection plate 36.

  By detecting the origin position, the maximum movement width of the sensor carriages 30a and 30b is set based on the origin position. The maximum movement width is set in a range in which the sensor carriages 30a and 30b can move.

  Next, the width of the print medium 4 is measured by moving the sensor carriages 30a and 30b from the origin position toward the maximum movement width. At this time, since one side of the printing medium (origin detection plate 36 side) and the other side can be detected, the width of the printing medium can be calculated. In addition, since the distance from the origin detection plate 36 to one side of the print medium 4 can be calculated, the transfer position of the print medium 4 can be calculated.

  In S106, when the width of the print medium is measured in S104, the print medium 4 is conveyed along the transfer path.

Next, in S108, a pitch mark is detected at the position determined and stored in S102. When the pitch mark detects the cast portion of the label continuum, the label is selected in S102, and the transmission sensor 10 moves to the center position in the width direction of the label continuum. In the case of a tag, the transmission sensor 10 reciprocates at the maximum width of the tag continuum to detect the hole.
In S102, when the reflective sensor 9 is selected, the reflective sensor 9 moves a predetermined distance toward the center in the width direction on the basis of one side of the label continuous body 4x. The predetermined distance can be arbitrarily set, but preferably, the reflective sensor 9 is moved to a distance of 5 to 15 mm from one side.
Further, when detecting the pitch mark, it is preferable to detect the pitch mark while reciprocating in the width direction between about 5 to 10 mm in the width direction of the print medium. (Detection area)
In addition, the position of the hole of the tag continuum can be set to the center, the left side, and the right side in advance by operating the operation unit. Thereby, since the range to detect becomes narrow, detection work can be made efficient. In this case, it is preferable that detection is performed while reciprocating the sensor in the width direction between about 2 to 5 mm in the width direction of the continuous tag body at the position set at each position. (Detection area)

If a pitch mark is detected in S108, it is next detected in S110 whether or not it is a stop position of the print medium.
If no tag is selected in “Tag?” In S102, the process returns to sensor type selection.

  If it is determined in S110 that the print medium is at the stop position, the conveyance of the print medium is stopped in S112. The stop position of the print medium is a position where the leading end of the label or the like stops at the print unit, or a position where the print medium stops at the print start position.

  In this way, it is detected whether or not the transmissive sensor 10 and the reflective sensor 9 of the sensor unit 20 are at the origin position. An operator inputs the pitch mark and its position, and selects whether to use the transmissive sensor 10 or the reflective sensor 9 from the input contents. In the case of the transmissive sensor 10, the print medium 4 is a continuous label. Step S102 for selecting whether the print medium 4 is a tag, Step S104 for measuring the width of the print medium 4 by the sensor unit 20, Step S106 for conveying the print medium 4 along the transfer path, Step S108 for detecting the pitch mark at the position of the pitch mark when the width is measured, and the stop position of the print medium when the pitch mark is detected An automatic position detection method for detecting the position of the print medium that does not require an operation of moving the sensor unit by the user by including step S110 for detecting whether or not there is and step S112 for stopping the conveyance of the print medium Can be provided.

  In S100, the transmission type sensor and the reflection type sensor of the sensor unit are set to the origin by the origin detection plate 36 provided with the elongated hole 38 formed long in the transport direction of the print medium 4 shown in FIGS. It is preferable to detect whether or not it is in a position.

  In this way, by first moving the transmissive sensor 10 and the reflective sensor 9 to the origin detection plate 36 and confirming the origin position, the maximum width that can be moved in the transport direction of the print medium 4 is recognized. be able to. In addition, it is preferable that there are three long holes 38, and when the long hole 38 is detected three times by the transmission type sensor, the transmission type sensor 10 and the reflection type sensor 9 recognize it as the origin and preferably stop.

  The present invention is not limited to the above-described embodiments, and each embodiment can be appropriately changed within the scope of the technical idea of the present invention. In addition, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment, and can be set to a suitable number, position, shape, and the like in practicing the present invention.

In this embodiment, the label or cardboard temporarily attached to the mount has been described as an example of the print medium. However, the present invention is not limited to this, and the pitch mark may be printed on a printable medium such as a film, a strip-shaped label without a mount, or a strip-shaped sheet. Any printed or processed one that can be detected by a sensor, such as a hole or notch, may be used.
In addition, the light emitting element 10b can be provided on the upper sensor carriage 30a, and the light receiving element 10a can be provided on the lower sensor carriage 32 facing the upper sensor carriage 30a.

  In this embodiment, the sensor unit is provided in the printer. However, the sensor unit can be arranged in a paper transport device, such as a paper transport device or a paper counter that counts the number of paper sheets. .

  Further, for example, a sensor unit as shown in FIGS. 7 and 8 may be used.

  FIGS. 7 and 8 are views showing a sensor unit of another embodiment from the front like the sensor unit 20 of FIG.

  In the sensor unit 40 of FIG. 7, two endless belts 42 </ b> A and 42 </ b> B are wound around a plurality of pulleys 44 a to 44 d so as to drive the top and bottom of the print medium 4 perpendicular to the transfer direction of the transfer path of the print medium 4. ing. The pulleys 24 a and 24 b are provided below the transfer path of the print medium 4, and the pulleys 24 c and 24 d are provided above the transfer path of the print medium 4. In the sensor unit 40, an endless belt 42A is wound around the pulley 24a, the pulley 24b, the pulley 24c, the pulley 24d, and the pulley 24a. In the sensor unit 40, an endless belt 42B is wound around the pulley 24a and the pulley 24b. Furthermore, the driving means 48 is provided in the pulley 44b. The pulley 44b is provided with a gear for transmitting driving from the driving means and a gear for driving the endless belt. The endless belt 42A is provided with an upper sensor carriage 50a, and the endless belt 42B is provided with a lower sensor carriage 50b. The upper sensor carriage 50a and the lower sensor carriage 50b are provided so as to be able to move in the width direction of the transfer path of the print medium 4 while facing each other. As a result, when the upper sensor carriage 50a and the lower sensor carriage 50b drive the driving unit 48 to rotate the pulley 44b, the upper sensor carriage 50a and the lower sensor carriage 50b face each other in the transfer path of the print medium 4. It is moved in the width direction.

  In the sensor unit 60 of FIG. 8, three endless belts 62A, 62B, and 63C are wound around a plurality of pulleys 64a to 64d so as to drive up and down the print medium 4 perpendicular to the transfer direction of the transfer path of the print medium 4. It is hung. The pulleys 64 a and 64 b are provided below the transfer path of the print medium 4, and the pulleys 64 c and 64 d are provided above the transfer path of the print medium 4. In the sensor unit 60, an endless belt 62A is wound around a pulley 64c and a pulley 64d. In the sensor unit 60, an endless belt 62B is wound around a pulley 64a and a pulley 64b. In the sensor unit 60, an endless belt 62C is wound around the pulley 64b and the pulley 64c in a cross shape. Furthermore, the driving means 68 is provided in the pulley 64b. The endless belt 62A is provided with an upper sensor carriage 70a, and the endless belt 62B is provided with a lower sensor carriage 70b. The upper sensor carriage 70a and the lower sensor carriage 70b are provided so as to be movable in the width direction of the transfer path of the print medium 4 in a state of being opposed to each other. Thus, when the upper sensor carriage 70a and the lower sensor carriage 70b drive the driving means 68 to rotate the pulley 64b, the upper sensor carriage 70a and the lower sensor carriage 70b face each other in the transfer path of the print medium 4. It is moved in the width direction.

  By configuring the sensor unit as in FIGS. 7 and 8, the transmissive sensor can be moved in the width direction of the print medium without moving the sensor unit itself in the width direction of the print medium. There is an effect that it is not necessary to secure a moving space of the sensor unit itself.

  The driving means 48 and 68 are preferably stepping motors as in the driving means 28. A support shaft can be provided along the moving direction of the upper sensor carriage 50a and the lower sensor carriage 50b of the sensor unit 40. Similarly, the sensor unit 60 can be provided with a support shaft.

  The sensor unit shown in FIGS. 7 and 8 is preferably provided with the origin detection plate 36 provided with the long hole 38 shown in FIGS. 3 and 4.

  Furthermore, the pulleys 24a to 24e provided in the sensor unit 20 of the present embodiment, the pulleys 44a to 44d provided in the sensor unit 40, and the pulleys 64a to 64d provided in the sensor unit 60 respectively mesh with the endless belt. A gear can be provided.

  The upper sensor carriage 50a can be provided with a light receiving element, and the lower sensor carriage 50b can be provided with a light emitting element and a light receiving element. The upper sensor carriage 70a can be provided with a light receiving element, and the lower sensor carriage 70b can be provided with a light emitting element and a light receiving element (both not shown). Further, the light emitting element can be provided on the upper sensor carriage.

  DESCRIPTION OF SYMBOLS 1 ... Printer, 2 ... Platen roller, 3 ... Thermal head, 4 ... Printing medium, 4 '... Label, 4a ... Black mark (pitch mark), 4b ... Hole (pitch mark), 4c ... Hole (pitch mark), DESCRIPTION OF SYMBOLS 5 ... Ink ribbon, 6 ... Paper supply part, 7 ... Ribbon supply part, 8 ... Ribbon winding part, 9 ... Reflection type sensor, 9a ... Light receiving element, 10 ... Transmission type sensor, 10a ... Light receiving element, 10b ... Light emitting element , 11 ... control unit, 20 ... sensor unit, 22 ... (one) endless belt, 24a ... roller, 24b ... roller, 24c ... roller, 24d ... roller, 24e ... roller, 26 ... gear, 28 ... driving means, 30a ... Upper sensor carriage, 30b ... Lower sensor carriage, 34a ... Shaft, 34b ... Shaft, 36 ... Origin detection plate, 38 ... Long hole, 40 ... Sensor unit, 42A Endless belt, 50a ... Upper sensor carriage, 50b ... Lower sensor carriage, 42B ... Endless belt, 60 ... Sensor unit, 62A ... Endless belt, 62B ... Endless belt, 62C ... Endless belt, 70a ... Upper sensor carriage, 70b ... Lower sensor carriage

Claims (7)

A sensor carriage provided with an optical sensor for detecting the print medium while transferring the print medium along a transfer path, and a sensor unit provided to move the sensor carriage by driving a belt. An automatic position detection method for detecting a pitch mark of a medium,
Measuring the width of the print medium by moving the sensor unit;
Conveying the print medium along the transfer path when the width of the print medium is measured;
Moving the sensor unit to a preset position;
Detecting the pitch mark;
And a step of stopping the conveyance of the printing medium when the pitch mark is detected.   The sensor carriage includes an upper sensor carriage provided with one element of a transmissive sensor for detecting the print medium, and a lower sensor carriage provided with the other element of the transmissive sensor. 2. The automatic position detecting method according to claim 1, wherein one element and the other element are positioned so as to face each other, and the upper sensor carriage and the lower sensor carriage are moved synchronously by driving of a belt.   Either one of the sensor carriages is provided with a reflective sensor, the transmissive sensor or the reflective sensor is used according to the pitch mark provided on the print medium, and the transmissive sensor or the The automatic position detecting method according to claim 2, further comprising: determining a region where the reflective sensor detects a pitch mark.   The automatic position detection method according to claim 3, further comprising: detecting whether or not the transmission type sensor and the reflection type sensor of the sensor unit are at the origin position, and moving to the origin position if they are not at the origin position. .   In the step of detecting whether the transmission type sensor and the reflection type sensor of the sensor unit are at the origin position, the sensor unit is detected by an origin detection plate provided with a long hole formed long in the transport direction of the print medium. The automatic position detecting method according to claim 4, wherein whether or not the transmission type sensor and the reflection type sensor are at the origin position is detected.   6. The belt according to claim 1, wherein the belt is a single endless belt wound around a plurality of pulleys so as to drive up and down of the print medium perpendicular to a transfer path of the print medium. The automatic position detecting method according to claim 1. A print carriage having a print head and a platen roller that is rotationally driven while being nipped and conveyed along a transfer path; a sensor carriage provided with an optical sensor for detecting the print medium; and the sensor carriage mounted on a belt A sensor unit provided to move by driving;
In the region where the width of the print medium is measured by the movement of the sensor unit, and when the width of the print medium is measured, the platen roller of the printing unit is rotated to convey the print medium and detect the pitch mark. And a control unit that detects the pitch mark, and controls to stop the transport of the print medium by stopping the platen roller of the print unit when the pitch mark is detected.

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