JP5759837B2 - Dot head and dot printer - Google Patents

Description

  Embodiments described herein relate generally to a dot head and a dot printer.

  In the dot head, an armature to which a printing wire is connected is swung between a printing position and a standby position. As the armature swings to the printing position, the wire protrudes from the front end surface of the head. Printing is performed by the leading end of the protruding wire colliding with a print medium such as paper via an ink ribbon. After this printing, the armature returns to the standby position by the urging force of the urging member. At this time, the armature comes into contact with the armature stopper and stops, and the wire returns.

  By the way, recently, high-speed printing is required, and the printing speed is increased. For this reason, the moving speed of the wire accompanying the swing of the armature increases, and when the armature comes into contact with the armature stopper at the time of return, the wire may rebound. In this case, the wire does not completely return to the head tip surface, and the tip portion protrudes from the head tip surface.

  However, when the tip of the wire protrudes from the tip of the head, there is a problem that the wire is caught on the ink ribbon, causing a printing defect or damaging the tip of the wire.

JP 2007-223334 A

  The problem to be solved by the embodiments is to provide a dot head and a dot printer that prevent the tip of the wire from being caught by a transfer material even when a wire for printing rebounds.

In the embodiment, the armature is rotated to the printing position and the tip of the printing wire protrudes from the tip of the head, so that the armature waits after contacting the printing medium via the transfer material and printing. A dot head that is rotated to a position, brought into contact with a stopper and stopped to be restored and held in a non-contact state with respect to the transport path of the print medium, and a mechanism for guiding the print medium is not provided in the protruded head distal end face, is separated from the previous SL head distal end face includes a transfer material guide that guides the transfer material in the most protruding surface at the head distal end face, protrudes during printing of the printing wire When the amount is A, the reband amount at the time of return is B, and the protrusion amount of the transfer material guide is C, the relationship of B <C <A is satisfied.

FIG. 2 is a central longitudinal front view schematically showing a dot head according to an embodiment. The figure which shows the ribbon guide provided in the front-end | tip part of the dot head of FIG. FIG. 2 is a schematic configuration diagram illustrating a printer including the dot head of FIG. 1.

  Hereinafter, embodiments will be described with reference to the drawings.

  FIG. 1 is a longitudinal side view schematically showing a dot printer 50 according to an embodiment.

  The dot printer 50 includes a main body case 51. An opening 53 is formed in the front surface 52 of the main body case 51. A manual feed tray 54 is provided in the opening 53 so as to be freely opened and closed. Further, a paper feed port 55 is formed at the lower part of the main body case 51 on the front surface 52 side, and a paper discharge receptacle 57 is provided on the rear surface 56 side. Further, an open / close cover 59 is rotatably provided on the upper surface 58 of the main body case 51. Here, the open / close cover 59 in an opened state is indicated by a virtual line.

  In the main body case 51, a paper transport path 60, which is a print medium transport path, is provided. The upstream side of the paper transport path 60 in the paper transport direction is connected to a paper feed path 61 disposed on the extended surface of the open manual feed tray 54 and a paper feed path 62 leading to the paper feed port 55, and The downstream side in the direction is connected to a paper discharge receiver 57. The paper feed passage 62 is provided with a tractor 63 for transporting paper.

  A conveyance roller 64 and a pressure roller 65 are disposed opposite to each other in the paper conveyance path 60, and the pressure roller 65 is in pressure contact with the conveyance roller 64. The transport roller 64 and the pressing roller 65 transport a sheet that is a print medium, and constitute a sheet transport unit that is a print medium transport unit. Further, the paper transport path 60 is provided with a printer unit 66 that performs a printing operation on the transported paper, and a paper discharge roller 67 is provided at the entrance of the paper discharge receiver 57. A pressing roller 68 pressed against the discharge roller 67 is rotatably supported on the free end side of the opening / closing cover 59.

  The printer unit 66 includes a platen 69 disposed in the paper transport path 60, a carriage 70 that can reciprocate in a direction orthogonal to the paper transport direction along the platen 69, and a dot head that will be described in detail after being mounted on the carriage 70. 1 and an ink ribbon cassette 71 and the like. The ink ribbon cassette 71 is detachably provided.

  The carriage 70 is driven by a motor (not shown) and reciprocates along the platen 69. The dot head 1 reciprocates in the main scanning direction as the carriage 70 reciprocates along the platen 69. For this reason, in the present embodiment, a head driving mechanism is realized by the carriage 70, a motor, and the like. Further, the dot printer 50 has a built-in drive control unit 72 that controls each unit in the main body case 51, and this drive control unit 72 drives and controls each unit such as the printer unit 66, the tractor 63, and the motor.

  In such a configuration, when a single sheet is used as a sheet as a printing medium, the sheet is fed from the manual feed tray 54, and when a continuous sheet is used as the sheet, the sheet is fed from the sheet feeding port 55. Regardless of which paper is used, the paper is transported by a transport roller 64 and discharged to a paper discharge receiver 57 by a paper discharge roller 67. In this process, printing is performed by the dot head 1.

  FIG. 2 is a central longitudinal front view schematically showing the dot head 1 described above.

  The dot head 1 includes a front case 2 and a rear case 3 that are coupled by a mounting screw (not shown). Between them, an armature 4, a wire guide 5, a yoke 6, an armature spacer 7, a circuit board 8, and the like are provided.

  The armature 4 includes an arm 9, a printing wire (hereinafter simply referred to as a wire) 10 brazed to one end in the length direction of the arm 9, and a magnetic circuit formed by welding on both side surfaces of the arm 9 in the width direction. A member 11 and a fulcrum shaft 12 are provided. An arcuate portion 13 is formed on the other end side of the armature 4. The magnetic circuit forming member 11 is provided with a surface to be attracted 14, and the attracted surface 14 is positioned at a central portion in the longitudinal direction of the armature 4.

  A plurality of such armatures 4 are arranged radially with respect to the axis of the yoke 6. The armature 4 is supported on the surface of the yoke 6 so as to be rotatable about the fulcrum shaft 12 in a direction away from the yoke 6, and is attached to the arm 6 in a direction away from the yoke 6 by the urging member 15. It is energized.

  When the armature 4 swings to the printing position, the wire 10 moves to a predetermined position, for example, a position where it collides with a printing medium such as paper, in accordance with the swinging operation of the armature 4.

  The wire guide 5 slidably guides the wire 10 so that the tip of the wire 10 collides with a predetermined position of the print medium. The front case 2 is provided with a tip guide 16 that aligns the tip of the wire 10 in a predetermined pattern and guides the wire 10 in a slidable manner.

  The rear case 3 is provided with a cylindrical portion 18 having a bottom surface portion 17 on one end side. A mounting recess 20 to which a metal annular armature stopper 19 is attached is formed at the center of the bottom surface portion 17, and the armature stopper 19 is attached by being fitted into the mounting recess 20.

  Here, when the armature 4 swings from the printing position by the urging member 15, the arm 9 which is a part of the armature 4 comes into contact with the armature stopper 19 and the swinging of the armature 4 stops. Therefore, the armature stopper 19 has a function of determining the standby position of the armature 4.

  The circuit board 8 includes a circuit for controlling the swinging of the armature 4 between the printing position and the standby position. During the printing operation, the arbitrary armature 4 is selectively swung by the control of the circuit board 8. Can be moved.

  The yoke 6 is made of a magnetic material and has a pair of cylindrical portions 21 and 22 having different diameters provided concentrically. The dimensions of the cylindrical portions 21 and 22 in the axial direction (up and down direction in FIG. 1) are set to be equal to each other. The cylindrical portion 21 on the outer peripheral side and the cylindrical portion 22 on the inner peripheral side are integrated by a bottom surface portion 23 provided so as to close one end side in the axial direction.

  A plurality of cores 27 arranged in an annular shape are integrally provided on the bottom surface portion 23 between the cylindrical portion 21 on the outer peripheral side and the cylindrical portion 22 on the inner peripheral side. A magnetic pole face 28 is formed at one end of each core 27 in the axial direction of the yoke 6. The magnetic pole surface 28 of the core 27 is provided so as to face the attracted surface 14 of the magnetic circuit forming member 11 provided in the armature 4. A coil 29 is mounted on the outer periphery of each core 27. That is, the yoke 6 has a plurality of cores 27 each having a coil 29 wound in a ring shape.

  In the dot head 1 configured as described above, the coil 29 is selectively excited when printing is performed. By this excitation, the armature 4 is attracted to the magnetic pole surface 28 of the core 27 and rotates around the fulcrum shaft 12. By this rotation of the armature 4, the tip of the wire 10 protrudes from the head tip surface 16a as shown in FIG. The leading end of the protruding wire 10 is pressed against the paper P on the platen 69 via the ink ribbon 80 as a transfer material, and printing is performed.

  When the energization of the coil 29 is interrupted, the armature 4 is restored by the urging force of the urging member 15 and comes into contact with the armature stopper 19. As a result, the armature 4 stops at the standby position, and the tip of the wire 10 returns to the head tip surface 16 side. Such a printing operation is performed at high speed.

  By the way, in the above-described printing, when the energization to the coil 29 is cut off and the armature 4 returns by the urging force of the urging member 15 and comes into contact with the armature stopper 19, particularly, the printing speed is increased (the armature 4 is For example, when it is swung between the printing position and the standby position at 2500 times / second), the wire 10 rebounds greatly, and the tip portion of the wire 10 protrudes greatly from the head tip surface 16a. In such a case, the leading end of the wire 10 may be caught by the ink ribbon 80, resulting in a printing failure or damage to the leading end of the wire.

  Therefore, in this embodiment, a ribbon guide 81 for guiding the ink ribbon 80 is provided at the head tip.

  Ribbon guides 81 are disposed on the upstream side and the downstream side, respectively, along the traveling direction of the ink ribbon 80 that travels along the head front end surface 16a as indicated by the arrows. The ribbon guides 81 have their tip portions protruding downward from the head tip surface 16a.

  When the amount of protrusion of the wire 10 at the time of printing described above is A, the amount of rebanding at the time of return is B, and the amount of protrusion of the ribbon guide 81 is C, the magnitude relationship is B <C <A. Yes.

  Accordingly, the ink ribbon 80 guided by the ribbon guide 81 is guided in a state of being separated from the head front end surface 16a by the distance C, and at the time of printing, it is pressed against the paper P by the front end portion of the wire 10 to enable printing. When the wire 10 is rebanded, the tip of the wire 10 does not reach the ink ribbon 80 and does not come into contact therewith.

  Thus, according to this embodiment, when the wire 10 is rebanded, it is possible to prevent the tip of the wire 10 from coming into contact with the ink ribbon 80, so that printing failure occurs or the tip of the wire is damaged. Can be reliably prevented.

  In the above-described embodiment, the ribbon guide 81 is disposed on the upstream side and the downstream side along the traveling direction of the ink ribbon 80. However, the present invention is not limited to this, and the tip of the wire 10 that rebounds is the ink ribbon. If it does not contact 80, a ribbon guide 81 may be provided on either the upstream side or the downstream side along the traveling direction of the ink ribbon 80.

  Moreover, the above-described embodiment is presented as an example, and is not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Dot head, 10 ... Printing wire, 16a ... Head front end surface, P ... Paper (printing medium), 64, 65 ... Print medium conveyance part, 69 ... Platen, 70 ... Carriage, 71 ... Ribbon cassette (transfer body conveyance) Part), 72 ... drive control part, 80 ... ink ribbon (transfer material), 81 ... transfer material guide.

Claims (3)

By rotating the armature to the printing position and causing the tip of the printing wire to protrude from the head tip, the armature is rotated to the standby position after printing by contacting the print medium via the transfer material. In a dot head that is restored by being brought into contact with the stopper and stopped , held in a non-contact state with respect to the transport path of the print medium, and not provided with a mechanism for guiding the print medium ,
The protruded head distal end face, is separated from the previous SL head distal end face includes a transfer material guide that guides the transfer material in the most protruding surface at the head distal end face,
When the protruding amount of the printing wire at the time of printing is A, the reband amount at the time of return is B, and the protruding amount of the transfer material guide is C,
A dot head having a relationship of B <C <A. The transfer material travels along the head front end surface,
The dot head according to claim 1, wherein the transfer material guide is disposed on at least one of an upstream side and a downstream side in a conveyance direction of the transfer material. The dot head according to claim 1 or 2,
A platen facing this dot head,
A carriage that holds the dot head and reciprocates along the platen;
A transfer body transporting section for transporting a transfer body between the dot head and the platen;
A print medium transport unit that transports a print medium between the transfer body and the platen;
A dot printer comprising: the dot head, the carriage, a transfer body transport unit, and a drive control unit that drives the print medium transport unit based on print data.

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