JP4653026B2 - Double-sided simultaneous printing thermal printer - Google Patents

Description

  The present invention relates to a double-sided printing thermal printer that performs printing on both sides of a thermal paper, and more particularly to a technique for obtaining a long-life and highly reliable printer.

  Thermal printers are used to print on receipts at restaurants, shops, and other registers. Ordinary receipts are printed on one side, and a large amount of receipt paper is used when there is a lot of information. Therefore, a double-sided simultaneous printing thermal printer may be used so that more information can be printed on the paper.

Conventional double-sided simultaneous printing thermal printers are provided with thermal heads and platen rollers on both sides (see, for example, Patent Document 1). The double-sided simultaneous printing thermal printer is used for printing a receipt of a register, for example, as a device capable of writing more information on thermal paper than on a single side.
Japanese Patent Laid-Open No. 11-286147

  The double-sided simultaneous printing thermal printer described above has the following problems. In other words, the increase in the number of printing sections increases the resistance of paper conveyance, increases the required power, and increases the damage and wear of each component.

  Therefore, the present invention provides a double-sided simultaneous printing thermal printer with long life and high reliability by reducing unnecessary contact and sliding as much as possible to reduce equipment damage and load during paper conveyance. The purpose is to do.

  In order to solve the above problems and achieve the object, the double-sided simultaneous printing thermal printer of the present invention is configured as follows.

A paper conveyance path formed from a paper supply section for supplying paper to a paper discharge port for discharging the paper, and a feed provided along the paper conveyance path and facing each other across the paper conveyance path have a roller and the pinch roller, the sheet, and a sheet transport mechanism for reverse transported toward the transport toward the paper discharge port, or the paper feed unit, located on the first side of the sheet conveying path, And a first thermal head provided on the paper discharge port side with respect to the feed roller, a first platen roller disposed opposite to the first thermal head across the paper conveyance path, and a paper conveyance path located on the second surface side, and a second thermal head which is provided between the first thermal head and the feed roller, the arranged opposite to the second thermal head across the paper conveyance path And the platen roller, the pinch roller, along with to sandwich the sheet between the feed rollers in the reverse transport of at least the sheet, and the pinch roller disjunction mechanism wherein during conveyance of the sheet which Ru is opened the clamping, the first thermal head, the thermal head detaching mechanism for clamping the sheet between said first platen roller during printing, wherein along the sheet conveying path, and the said first thermal head second A paper cue sensor that is provided between the thermal head and detects the front end of the paper; and when the front end of the paper is detected by the paper cue sensor when the paper is conveyed or reversely conveyed, The paper is transported backward to the second thermal head, the paper is transported therefrom, and printing is started by the second thermal head. If There has reached the first thermal head, and a control unit which Ru printing is started by the first thermal head is provided on the second platen roller, only if the second platen roller rotates in the opposite conveying direction, cutting the driving force from the driving dynamic motor, characterized in that it includes a selective torque transmission mechanism for imparting the driving force in the case of rotating in the conveying direction.

  According to the present invention, by reducing unnecessary contact and sliding as much as possible, it is possible to reduce damage to equipment and load during paper conveyance, and to obtain a long-life and highly reliable device. It becomes.

  1 is a side view showing a double-sided simultaneous printing thermal printer 10 according to an embodiment of the present invention from one side, FIG. 2 is a side view showing the double-sided simultaneous printing thermal printer 10 from the other side, and FIGS. 5 is a flowchart showing the operation of the double-sided simultaneous printing thermal printer 10, and FIG. 6 is an explanatory view showing the cam position of the cam mechanism 80 in each operation of the double-sided simultaneous printing thermal printer 10.

  As shown in FIG. 1, the double-sided printing thermal printer 10 includes a housing 11, a paper supply unit 20 that is housed in the housing 11 and supplies paper P such as thermal paper, a first printing unit 30, A first printing unit 30 and a second printing unit 40 disposed between the paper supply unit 20; a driving unit 50 for driving each unit; a cutter device 90 for cutting printed paper P; And a control unit 100 for controlling.

  The paper supply unit 20 includes a holding unit 21 that holds the thermal paper roll R, a feed mechanism (paper conveyance mechanism) 23 that conveys the paper P from the holding unit 21 toward the cutter device 90 along the paper conveyance path 22, and A sheet sensor 24 disposed in front of a pinch roller 27 described later, and a sheet cue sensor 25 disposed between the first printing unit 30 and the second printing unit 40 are provided. Outputs of the paper sensor 24 and the paper cueing sensor 25 are input to the control unit 100 and determine the operation timing of each unit.

  The feed mechanism 23 includes a feed roller 26 and a cylindrical pinch roller 27 provided so as to sandwich the paper transport path 22 with the feed roller 26. The pinch roller 27 is provided on a roller arm (pinch roller attaching / detaching mechanism) 28 that is swingably mounted in the direction of arrow S in FIG. 1 around a pinch roller crankshaft M in a direction perpendicular to the paper surface. The roller cam 81 is configured so as to be able to come in contact with the feed roller 26 by the operation of the roller cam 81.

  In the first printing unit 30, the first thermal head 31 and the first platen roller 32 are arranged to face each other so as to sandwich the paper conveyance path 22. The first thermal head 31 is attached to a head arm (thermal head attaching / detaching mechanism) 33 that is pivotably mounted in the direction of arrow T in FIG. 1 around the first thermal head crankshaft K in a direction perpendicular to the paper surface. It is provided so that it can be separated from and contacted with the first platen roller 32 by the operation of a thermal head cam 82 described later.

  In the second printing unit 40, the second thermal head 41 and the second platen roller 42 are arranged to face each other so as to sandwich the paper conveyance path 22. The second platen roller 42 is provided with a one-way gear (selective rotational force transmission mechanism) 43 that is disconnected from the gear mechanism 60 when rotating in the reverse conveyance direction.

  The first platen roller 32, the second platen roller 42, and the feed roller 26 are configured to be able to rotate forward and backward via a gear mechanism 60 that transmits a rotational force of a drive motor 51 described later. Further, the second platen roller 42 is configured not to rotate reversely even when interlocked during reverse rotation conveyance by a one-way gear 43 provided on the axis of the second platen roller 42. Further, the sheet conveyance amount of the first platen roller 32 is set to be larger than the sheet conveyance amount of the second platen roller 42 to such an extent that printing can be appropriately performed. The pinch roller 27 is a driven roller.

  The drive unit 50 includes a drive motor 51, a gear mechanism 60 that transmits the rotational force of the drive motor 51 to each unit, and a cam mechanism 80.

  The cam mechanism 80 includes a first gear 61 that transmits power from the drive motor 51 to another gear. A second gear 62 is engaged with the first gear 61. A pinch roller cam 81 is attached to the second gear 62. The first gear 61 further meshes with a third gear 63, a fourth gear 64, and a fifth gear 65 in order. A thermal head cam 82 is attached to the fifth gear 65.

  The second gear 62 and the fifth gear 65 are connected to the drive motor 51 at different reduction ratios (2: 1 in the present embodiment). The roller cam 81 and the thermal head cam 82 are provided with cam position sensors 83 and 84, respectively, to detect the positions of the roller cam 81 and the thermal head cam 82. Since the roller cam 81 and the thermal head cam 82 are directly connected by the gear mechanism 60, either one of the position sensors may be used.

  The double-sided simultaneous printing thermal printer 10 configured as described above operates as follows. FIG. 3 is a flowchart showing the paper setting operation. The paper P is set from the right side of the feed roller 26 in FIG. 1 (ST10). When the leading edge of the paper P is detected by the paper sensor 24 (ST11), the cam mechanism 80 is operated by the drive motor 51 to rotate the roller cam 81 and the thermal head cam 82 to adjust the angle (ST12). The angular positions of the roller cam 81 and the thermal head cam 82 are set to 0 ° as indicated by G1 in FIG. As a result, the pinch roller 27 and the first thermal head 31 are positioned to open the paper transport path 22. Subsequently, the feed mechanism 23 is operated by the drive motor 51 to convey the paper P.

  Next, when the leading edge of the sheet P conveyed by the feed mechanism 23 is detected by the sheet cue sensor 25, the cam mechanism 80 causes the roller cam 81 to be at an angular position of 180 ° as indicated by G2 in FIG. The thermal head cam 82 rotates to an angular position of 90 °. At this time, the pinch roller 27 is in the clamping position, and the first thermal head 31 is in the open position. At this time, the feed mechanism 23 performs reverse rotation conveyance. That is, the first platen roller 32 and the feed roller 26 rotate in reverse, but the second platen roller 42 is connected to the one-way clutch 43 and thus does not rotate in reverse. Further, since the first thermal head 31 is in the open position, the paper P does not slide on the first thermal head 31, and the load on the drive motor 51 is low.

  When the paper P is returned by a specified amount, the print start position of the paper P is applied to the second thermal head 41, the paper cue sensor 25 is turned off, and the feed mechanism 23 is stopped.

  FIG. 4 is a flowchart showing printing and paper cutting operations. As described above, when the printing start position of the paper P is applied to the second thermal head 41, printing is started by the second printing unit 40 (ST20). The feed mechanism 23 performs forward rotation conveyance. At this time, the angular positions of the roller cam 81 and the thermal head cam 82 are the positions indicated by G3 in FIG. This position is the same as G2 in FIG. 6, the roller cam 81 is at an angular position of 180 °, and the thermal head cam 82 is at an angular position of 90 °. Therefore, the cam mechanism 80 is in a stopped state as it is.

  When printing is finished in the second printing unit 40, the paper P is detected by the paper cueing sensor 25 (ST21) and conveyed by a specified amount (ST22). The specified amount at this time is an amount that passes through the first thermal head 31 through the printing start position of the paper P.

  When the specified amount is conveyed or when the printing start position of the paper P passes through the first thermal head 31, the cam mechanism 80 is operated, and as shown by G4 in FIG. 6, the roller cam 81 is 360 °, the thermal head cam. 82 is an angular position of 180 °. At this time, the pinch roller 27 is in the open position, and the first thermal head 31 is in the clamping position. Here, printing is started in the first printing unit 30 (ST23).

  When printing is completed in the first printing unit 30, the roller cam 81 is at 180 ° and the thermal head cam 82 is at 90 °, as indicated by G5 in FIG. At this time, the pinch roller 27 is in the clamping position, and the first thermal head 31 is in the open position. Here, the paper P is cut by the cutter device 90 (ST24).

  After cutting, the roller cam 81 is at 180 ° and the thermal head cam 82 is at 90 °, as indicated by G6 in FIG. This is the same as the angular position of G5 in FIG. 6, and in this case, the cam mechanism 80 is still stopped. Reverse feed is performed by the feed mechanism 23 (ST25), the paper P is returned by a specified amount, and the paper cueing sensor 25 is turned off (ST26). When the sheet P returns by the specified amount, the printing start position of the sheet P is applied to the second thermal head 41, and the feed mechanism 23 stops (ST27). Until the paper P, which is the paper, runs out of paper, the process returns to ST20 and printing in the second printing unit 40 is performed.

  In the operation described above, the position of the cam mechanism 80 is the same in G2 and G3 in FIG. 6 and in G5 and G6 in FIG. However, in G3 and G5 in FIG. 6, the pinch roller 27 may be opened at the positions of G3 and G5 in FIG. 6, and when the cam mechanism 80 is moved to the open position, G2 and G3 in FIG. The position of the cam mechanism 80 of G6 changes.

  FIG. 5 is a flowchart showing the operation when the paper is out. During printing or after completion of printing (ST30), if no paper is detected by the paper sensor 24 (ST31), printing is stopped (ST32). At this time, as indicated by G7 in FIG. 6, the roller cam 81 is at 540 ° and the thermal head cam 82 is at 270 °. At this time, the pinch roller 27 is in the clamping position, and the first thermal head 31 is in the open position. Further, the feed mechanism 23 rotates in the reverse direction, and all the paper P is returned to the paper transport path entrance. When all the sheets P are returned, the sheets are manually removed (ST33).

  Subsequently, the paper setting operation shown in FIG. 3 is performed. At this time, the cam mechanism 80 is positioned at 720 ° for the roller cam 81 and 360 ° for the thermal head cam 82, as indicated by G8 in FIG. Each cam of the cam mechanism 80 at this time is at the same position as G1 in FIG. 6 and is a position where the pinch roller 27 and the first thermal head 31 are opened.

  As described above, according to the double-sided simultaneous printing thermal printer 10 according to the present embodiment, the first thermal head 31 and the first platen roller 32 until the leading edge of the paper P reaches the position of the first printing unit 30. By releasing the nipping and causing the paper P to be nipped by the first thermal head 31 and the first platen roller 32 only during printing, sliding between the first thermal head 31 and the paper P can be minimized. Further, during forward rotation, the pinch roller 27 is positioned so as to move to a position where it is released from the feed roller 26. Therefore, it is possible to reduce the load on paper conveyance.

  By reducing the power required for paper conveyance, for example, when a motor is used for paper conveyance, the size can be reduced. Further, since consumable parts such as a thermal head are not always sandwiched, damage and wear due to a paper edge or the like can be minimized. As a result, a compact and long-life double-sided simultaneous printing thermal printer can be obtained.

  Further, since the paper conveyance amount of the first platen roller 32 is larger than the paper conveyance amount of the second platen roller 42, an appropriate tension is applied when the paper P is conveyed in the forward direction, and the thermal paper is smoothly bent without being bent. Can be transported. Further, when the paper P is transported in the reverse direction, the second platen roller 42 is not applied with a driving force during the reverse rotation, so that the paper P is transported by the first platen roller 32. Note that the pinching pressure of the pinched rollers 27 is adjusted to be low so that the sheet conveyance amount during conveyance in the reverse direction is equal to the sheet conveyance amount of the first platen roller 32.

  As described above, according to the double-sided printing thermal printer 10 according to the present embodiment, the first thermal head 31 and the pinch roller 27 are opened as necessary, so that damage and wear can be reduced, and at the time of paper conveyance. The load is reduced, and the drive motor 51 can be downsized. Therefore, it has a long life and high reliability.

  The present invention is not limited to the above embodiment. For example, in the above-described example, the second thermal head has been described as being configured so as not to be separated from or brought into contact with the second thermal head. The cam angle in each state and the ratio of the gear portion of the cam mechanism have been described above, but this can be variously modified as long as the above operation is performed. Although it has been described that the cam mechanism is used to bring the thermal head and the pinch roller into contact with each other, a crank mechanism or the like can be applied. In addition, various modifications can be made without departing from the scope of the present invention.

The side view which shows the double-sided printing thermal printer which concerns on one embodiment of this invention from one side. The side view which shows the same double-sided simultaneous printing thermal printer from the other side. The flowchart which shows operation | movement of the double-sided simultaneous printing thermal printer. The flowchart which shows operation | movement of the double-sided simultaneous printing thermal printer. The flowchart which shows operation | movement of the double-sided simultaneous printing thermal printer. Explanatory drawing which shows the cam position of the cam mechanism in each operation | movement of the double-sided simultaneous printing thermal printer.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Duplex printing thermal printer, 20 ... Paper supply part, 22 ... Paper conveyance path, 23 ... Feed mechanism (paper conveyance mechanism), 24 ... Paper sensor, 25 ... Paper cue sensor, 26 ... Feed roller, 27 ... Pinch roller 28 ... roller arm, 30 ... first printing section, 31 ... first thermal head, 32 ... first platen roller, 40 ... second printing section, 41 ... second thermal head, 42 ... second platen roller, 43 ... One-way gear, 50... Drive unit, 51... Drive motor, 60... Gear mechanism, 80.

Claims (5)

A paper conveyance path formed from a paper supply unit for supplying paper to a paper discharge port for discharging the paper;
Provided along the sheet conveying path, have a feed roller and a pinch roller provided to face each other across the sheet conveying path, the sheet, conveyed toward the sheet discharge port, or the paper feed A paper transport mechanism that transports backward toward the
A first thermal head located on the first surface side of the paper transport path and provided on the paper discharge port side with respect to the feed roller;
A first platen roller disposed opposite to the first thermal head across the paper transport path;
A second thermal head located on the second surface side of the paper transport path and provided between the first thermal head and the feed roller ;
A second platen roller disposed opposite to the second thermal head across the paper transport path;
The pinch roller, along with to sandwich the sheet between the feed rollers in the reverse transport of at least the sheet, and the pinch roller disjunction mechanism Ru said during conveyance of the sheet by opening the clamping,
A thermal head attaching / detaching mechanism for holding the paper between the first thermal head and the first platen roller at the time of printing;
A paper cue sensor provided along the paper transport path and between the first thermal head and the second thermal head for detecting the leading edge of the paper;
If the paper is conveyed or reversely conveyed and the leading edge of the paper is detected by the paper cueing sensor, the paper is reversely conveyed to the second thermal head, the paper is conveyed therefrom, and the second thermal is detected. printing is started in the head, said if the paper has reached the first thermal head, control unit Ru is initiated printed by the first thermal head,
Provided on the second platen roller, only if the second platen roller is rotated in the reverse transport direction, cutting the driving force from the driving movement motor, when rotated in the conveying direction to impart the driving force A double-sided simultaneous printing thermal printer comprising a selective rotational force transmission mechanism.   2. The double-sided device according to claim 1, further comprising a paper sensor provided along the paper conveyance path and on the paper supply unit side with respect to the feed roller, and detecting a leading edge of the paper. Simultaneous printing thermal printer.   The double-sided simultaneous printing thermal printer according to claim 1, wherein the pinch roller separation mechanism and the thermal head separation mechanism are driven by the same drive motor.   The double-sided simultaneous printing thermal printer according to claim 1, wherein the first platen roller, the second platen roller, and the feed roller are driven by the same drive motor. The paper conveyance amount of the first platen roller is set larger than the paper conveyance amount of the second platen roller so that an appropriate tension is applied when the paper is conveyed. Double-sided printing thermal printer as described.

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