JP2016117565A - Recording medium transportation mechanism and printer - Google Patents

Abstract

Even when a recording medium having different specifications is used, stable conveyance of the recording medium is realized. A recording medium transport mechanism 30 transports a recording medium on which information is recorded along a transport path 32 having a planar area, and a plurality of feed rollers 38 and the feed rollers 38 are separated by a predetermined interval. A main driving roller set 36 that is rotated by obtaining a driving force, and a rotatable driven roller 37 that is pressed with a predetermined pressure individually corresponding to the feed roller 38. The roller holding shaft 39 of the main driving roller set 36 is supported in a direction against a reaction force generated by the feed roller 38 and the driven roller 37 by shaft support members 55 and 56 at predetermined portions in the axial direction. ing. [Selection] Figure 3

Description

  The present invention relates to a recording medium transport mechanism and a printer including the same.

  The recording wire is moved through the ink ribbon impregnated with the ink while moving the recording head including a plurality of recording wires in a direction intersecting the conveying direction of the recording medium with respect to the recording medium conveyed along the plane. A serial dot impact type printer that selectively protrudes and records information is known (for example, see Patent Document 1). Since this type of printer conveys a recording medium along a plane, information can be recorded on many types of recording media.

JP 2003-266873 A

  The above-described printer is used in various business fields because it can record information on various recording media. Printers also use different recording media depending on the business mode. For example, there is a demand for properly using a copy sheet in which a plurality of sheets are laminated, a cut sheet with different thicknesses, or a booklet in which sheets are bound and bound on one side as a recording medium. Therefore, there is a demand to realize stable conveyance of the recording medium even for recording media of different specifications.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  (Application example 1) A recording medium transport mechanism for transporting a recording medium on which information is recorded along a transport path having a flat area, and holds a plurality of feed rollers and the feed rollers at a predetermined interval. A main driving roller set comprising a roller holding shaft and rotating by obtaining a driving force; and a rotatable driven roller pressed at a predetermined pressure individually corresponding to the feed roller, and the main driving roller set The recording medium transport mechanism, wherein the roller holding shaft is supported by a shaft support member in a direction against a reaction force generated by the feed roller and the driven roller at a predetermined portion in the axial direction.

  In recent years, among the recording medium transport mechanism composed of a main driving roller and a driven roller pressed by the main driving roller, the main driving roller in particular is divided into a plurality of parts for the purpose of cost reduction and weight reduction, and each roller is used as a roller holding shaft. There is a thing of the form to hold. When a main driving roller divided into a plurality of parts is used, the deflection of the roller holding shaft may change depending on the difference or type of the thickness of the recording medium. If the deflection of the roller holding shaft changes, the pressing force between the feed roller and the corresponding driven roller in the width direction of the recording medium will change, causing a difference in the conveyance force, which may cause the recording medium to skew or meander There is.

  According to this configuration, even when a recording medium having a different thickness is used and the reaction force changes, the roller holding shaft of the main driving roller set can be supported in a direction against the reaction force at a predetermined portion in the axial direction. . Therefore, excessive deflection of the roller holding shaft can be reduced. As a result, it is possible to reduce a change in pressing force of each pair of the feeding roller and the driven roller, and it is possible to reduce a difference in conveying force in the width direction of the recording medium. Therefore, stable running can be realized even with recording media of different types and thicknesses.

  (Application example 2) The plurality of driven rollers are respectively arranged at positions corresponding to the feed rollers, and each driven roller is pressed by an elastic member and pressed by the feed rollers. Recording medium transport mechanism.

  According to this configuration, the driven roller is individually pressed against the feed roller by the elastic member. Therefore, the pressing force of the set of each feed roller and driven roller can be set to a predetermined pressure. As a result, even if a deflection occurs in the axial direction of the roller holding shaft, it is possible to reduce variations in the pressing force of each pair of the feed roller and the driven roller. Therefore, the difference in feed force in the width direction of the recording medium can be reduced, and stable running of the recording medium can be realized.

  (Application Example 3) At least two main driving roller sets are arranged at a predetermined interval in the conveyance direction of the recording medium, and one of the main driving roller sets is arranged on one surface side of the recording medium. And the other main driving roller set is disposed on the other surface side of the recording medium.

  According to this configuration, a conveyance force can be applied to both sides of the recording medium to be conveyed by the main driving roller set. Therefore, stable conveyance of the recording medium can be realized.

  (Application Example 4) The roller holding shaft of one of the main driving roller sets is supported by the shaft supporting member having a projection having a surface that supports the sliding while sliding the shaft surface, and the other main driving roller set The recording medium transport mechanism according to claim 1, wherein the roller holding shaft is supported by the support member having an arcuate sliding surface that is supported while sliding the circumference of the shaft.

  According to this configuration, the other side of the recording medium, for example, the front side, is supported by the protrusions protruding from the lower side of the roller holding shaft of the main driving roller set disposed on one side of the recording medium, for example, the back side. Can be supported by a support member having an arcuate sliding surface protruding from the lateral direction. Therefore, even if the main driving roller set is arranged on both sides of the recording medium, the roller holding shaft can be supported without hindering the conveyance of the recording medium.

  (Application example 5) The roller holding shaft of the main driving roller set spans between two wall portions arranged at opposite positions, and is a latch receiving portion provided in the direction of one end of the roller holding shaft. The recording medium transport mechanism according to claim 1, wherein the recording medium transport mechanism is locked to a locking portion provided on one of the two wall portions.

  According to this configuration, the main driving roller set can be attached between two wall portions arranged at opposite positions.

  Application Example 6 The locking portion of the wall portion has a hook portion, and is a rod-like member that bends in the radial direction of the roller holding shaft, and the locking receiving portion of the roller holding shaft is the roller In the movement of the holding shaft in the axial direction, an annular inclined surface portion in which the hook portion slides and the rod-shaped member bends in the radial direction of the roller holding shaft, and an annular hook receiving portion that is lowered by one step from the apex portion of the annular inclined surface portion, The recording medium transport mechanism as described above.

  According to this configuration, the main driving roller set is moved between the wall portions in a direction intersecting the wall portions, whereby the hook portion of the locking portion of the wall portion is changed to the annular inclined surface portion of the locking receiving portion of the roller holding shaft. And then the hook portion can be lowered into the annular hook receiving portion. Therefore, the main driving roller set can be rotatably supported between the two wall portions.

  (Application example 7) The above-described recording medium conveyance mechanism that conveys a recording medium on which information is recorded along a conveyance path having a planar area, and a carriage that mounts a recording head having a plurality of recording wires. A printer that records information on the recording medium by selectively projecting the recording wire of the recording head while moving the carriage in a direction intersecting the conveyance direction of the recording medium.

  According to this configuration, even if recording media of different types and thicknesses are used, the difference in conveying force in the width direction of the recording media can be reduced. Therefore, it is possible to provide a printer that can cope with recording media of different types and thicknesses and can realize stable running of the recording media.

1 is an external perspective view of a printer according to the present invention. FIG. 4 is a diagram illustrating an example of a recording medium applied to a printer. FIG. 3 is an external perspective view of main components of the printer body. FIG. 2A and 2B illustrate a recording medium conveyance mechanism and a recording mechanism. The figure explaining the attachment method of a feed roller group. The schematic diagram explaining a shaft support member.

  Hereinafter, the present embodiment will be described with reference to the drawings. In the drawings referred to in the following description, the vertical and horizontal scales of members or parts may be shown differently from the actual ones for convenience of description and illustration.

(About overall printer configuration)
First, the overall configuration of the printer will be described with reference to FIG. FIG. 1 is an external perspective view of a printer according to the present invention. In the following description, a dot impact type printer that records information on a recording surface of a recording medium through an ink ribbon impregnated with ink using a recording head including a recording wire will be described as an example of the printer. . 1 indicates the conveyance direction of the recording medium, the Y direction indicates the width direction of the recording medium, and the Z direction indicates a direction orthogonal to the X direction and the Y direction.

  As shown in FIG. 1, the printer 10 accommodates a printer main body 20 (see FIG. 3), which will be described later, in an exterior case 12 including an upper case 12a and a lower case 12b. A supply / discharge port 14 is provided in the X (+) direction at the boundary between the upper case 12a and the lower case 12b, and a supply port 15 is provided in the X (−) direction. A recording medium guide 16 that guides the supply and discharge of the recording medium is extended to the supply / discharge port 14. A front cover 18 that can be opened and closed is disposed at the top of the supply / discharge port 14 in the Z direction. A switch panel 19 is provided on the upper case at the top of the front cover 18.

  The printer 10 described above supplies a recording medium from the supply / discharge port 14 or the supply port 15, records information on the recording medium, and discharges it along the recording medium guide 16 of the supply / discharge port 14. The recording medium guide 16 has a flat recording medium placement surface 17 and has a function of guiding the supply of the supplied recording medium and placing a recording medium on which information is recorded. Further, by opening the front cover that can be opened and closed, the printer main body 20 in the outer case 12 is exposed. For example, replacement of a ribbon cassette 80 (see FIG. 4) described later, removal of a recording medium that has caused a conveyance failure, and each mechanism Maintenance of parts can be performed.

(About recording media)
Here, an example of a recording medium used in the printer according to the present embodiment will be described with reference to FIG. FIG. 2 is a diagram illustrating an example of a recording medium applied to the printer. Note that the X direction, Y direction, and Z direction shown in FIG. 2 indicate the same directions as the X direction, Y direction, and Z direction shown in FIG. 1 when the recording medium is applied to a printer.

  The dot impact printer 10 according to the present embodiment selectively uses a fanfold paper F, a standard size cut sheet T, or the like as a recording medium. The fanfold paper F is composed of, for example, a plurality of long carbonless paper using a color reaction such as a leuco dye, or a plurality of carbon papers coated with carbon ink on the back of the long paper P. .

  As shown in FIG. 2A, the fanfold paper F is configured so that perforations M are provided at predetermined intervals along the X direction of the long paper P and can be cut in the Y direction. Are alternately folded and stacked in the opposite direction. Further, the fanfold paper F has sprocket holes S formed in rows at a predetermined pitch on both side edges Fa and Fb along the X direction. The sprocket hole S can be engaged with a tractor pin of a tractor unit 33 of a recording medium transport mechanism 30 (see FIG. 4) described later. The number of sheets of such fanfold paper F to be overlaid is set depending on the application, and both side edges Fa and Fb are fixed by gluing or partial embossing. When pressure is applied by a recording wire (not shown) of the printer 10, the non-carbon paper or carbon paper is colored at the pressurized portion, and character information and the like are copied and recorded.

  In the present embodiment, the fanfold paper F is supplied from the supply port 15 of the printer 10 shown in FIG. 1, and information is recorded and discharged from the supply / discharge port 14. Further, as shown in FIG. 2B, as a recording medium, for example, a standard size such as A4 to A3 or a cut sheet T having an arbitrary size is also used. The cut sheet T may vary in thickness depending on the application. In the present embodiment, the cut sheet T is supplied from the supply / discharge port 14 of the printer 10 shown in FIG. Further, although not shown, the recording medium may be in the form of a booklet in which a plurality of sheets such as a passbook are bound, or in the form of a bag such as an envelope. The material of the recording medium may be paper, a synthetic resin sheet, or a film. Further, the surface may be processed such as coating or infiltration.

(About the printer)
Next, the printer body will be described with reference to FIGS. FIG. 3 is an external perspective view of main components of the printer main body, and FIG. 4 is a side sectional view of the printer main body. FIG. 5 is a diagram illustrating the recording medium transport mechanism and the recording mechanism. In addition, the X direction, Y direction, and Z direction shown in FIGS. 3-5 show the same direction as the X direction, Y direction, and Z direction shown in FIG.

  The printer main body 20 includes a main body frame 22, a recording medium transport mechanism 30, and a recording mechanism 50. As shown in FIG. 3, the main body frame 22 is formed by bending a sheet metal or the like, and includes a base frame 23 that constitutes a lower portion of the printer main body 20, a main frame 24 erected on the base frame 23, and a base frame 23 and a left side frame 25 and a right side frame 26 connected to both ends of the main frame 24 in the Y direction. The main body frame 22 forms an outer shell of the printer main body 20 and has a function of supporting and fixing each mechanism.

  As shown in FIG. 5, the recording medium transport mechanism 30 includes a tractor unit 33 and a first transport roller pair 35 in the X (−) direction, that is, in order from the supply port 15 along the transport path 32 along which the recording medium is transported. And a second transport roller pair 41.

  The tractor unit 33 includes a tractor belt 34 formed with a tractor pin 34a that can be inserted into the sprocket hole S of the fanfold paper F shown in FIG. 2, and a drive sprocket 33a and a driven sprocket 33b around which the tractor belt 34 is bridged. It has. The tractor units 33 are respectively arranged on both sides of the transport path 32 in the Y direction so as to correspond to the sprocket holes S at both ends in the width direction of the fanfold paper F being transported.

  The drive sprocket 33a is connected to a feed motor (not shown), and rotates by obtaining a drive force from the feed motor. Therefore, the tractor unit 33 rotates the tractor belt 34 provided with the tractor pin, and the tractor pin 34a and the sprocket hole S formed on the fanfold paper F are sequentially engaged, whereby the fanfold paper F is removed. Transport in the desired direction. Note that a portion where the tractor pin 34a and the sprocket hole S of the fanfold paper F are engaged is covered with an openable / closable tractor cover 31.

  The first transport roller pair 35 has a feed roller group 36 as a main driving roller group and a press roller 37 as a driven roller. The feed roller set 36 is provided on the upper side in the Z direction of the transport path 32 so as to cross the transport path 32. The feed roller set 36 is connected to a feed motor (not shown), and rotates by obtaining a driving force from the feed motor. Therefore, the recording medium sandwiched between the feed roller set 36 and the pressing roller 37 can be transported along the transport path 32 in any direction.

  The second transport roller pair 41 is arranged in the X (+) direction of the first transport roller pair 35 and has a feed roller group 36 as a main driving roller group and a press roller 37 as a driven roller. The feed roller set 36 is provided below the transport path 32 in the Z direction so as to cross the transport path 32. The presser roller 37 is attached to a rotary presser roller attaching member 58 as a driven roller holding member. The rotary presser roller mounting member 58 is provided so as to be rotatable in the direction of arrow A, and can turn the feed roller set 36 and the presser roller 37 to be in pressure contact with each other or separated from each other.

  The feed roller set 36 is connected to a feed motor (not shown), and rotates by obtaining a driving force from the feed motor. Therefore, the recording medium sandwiched between the feed roller set 36 and the pressing roller 37 can be transported along the transport path 32 in any direction. The recording medium guide 16 is disposed in the X (+) direction of the second transport roller pair 41, that is, in the supply / discharge port 14.

The recording medium conveyance mechanism 30 having the above-described configuration is configured to convey the fanfold paper F as a recording medium supplied from the supply port 15 by the tractor unit 33, the first conveyance roller pair 35, and the second conveyance roller pair 41. Can be discharged in the X (+) direction and discharged onto the recording medium mounting surface 17 of the recording medium guide 16 of the supply / discharge port 14. Further, the cut sheet T guided and supplied by the recording medium guide 16 of the supply / discharge port 14 is moved in the X (−) direction along the conveyance path 32 by the first conveyance roller pair 35 and the second conveyance roller pair 41. It can be conveyed forward and backward in the X (+) direction and discharged again onto the recording medium placement surface 17 of the recording medium guide 16 of the supply / discharge port 14.
Details of the recording medium transport mechanism 30 according to the embodiment of the present invention will be described later.

  As shown in FIG. 4, a first recording medium detection device 52 is provided in the vicinity of the feed roller set 36 of the second transport roller pair 41. The first recording medium detection device 52 is installed below the transport path 32 in the Z direction. It is a sensor that detects the position or presence of the leading edge of the recording medium by contacting the leading edge or the back surface of the recording medium. The first recording medium detection device 52 includes a substantially box-shaped main body 52a, and a detection lever 53 and an optical sensor unit 54 are provided on the main body 52a. The detection lever 53 is formed in a bar shape at one end, which is the upper end, and partially protrudes in the transport path 32. The detection lever 53 is disposed so as to be swingable about a predetermined support portion, and the other end portion is disposed so as to be able to cross between a light emitting portion and a light receiving portion (not shown) of the sensor unit 54.

  In the first recording medium detection device 52 having the above-described structure, the upper end portion of the detection lever 53 comes into contact with the front end or the back surface of the recording medium conveyed along the conveyance path 32 and swings around a predetermined support portion. Then, when the other end of the detection lever 53 crosses between the light emitting portion and the light receiving portion of the sensor unit 54, it is possible to detect the leading edge or the presence or absence of the recording medium as an electric signal of the sensor unit 54. Further, it is preferable to provide a second recording medium detection device 59 using a reflective optical sensor in the vicinity of the first transport roller pair 35.

  The recording mechanism 50 shown in FIGS. 3 and 5 is disposed between the first transport roller pair 35 and the second transport roller pair 41 along the transport path 32, and includes the recording head 51, the platen 21, and the carriage 60. A carriage moving mechanism 70 and a ribbon feeding mechanism 75. The recording head 51 includes a plurality of recording wires (not shown) and electromagnets corresponding thereto. The recording head 51 operates the electromagnet according to a recording signal transmitted from a control unit (not shown) to selectively protrude the recording wire.

  The recording head 51 is mounted on the carriage 60 in a posture capable of projecting a recording wire toward the conveyance path 32 side. The carriage 60 is preferably made of plastic as a material, and includes a carriage main body 61 and a recording head holding unit 64. The carriage body 61 is provided with a carriage guide hole 62 through which a carriage shaft 27 spanned between the left side frame 25 and the right side frame 26 is slidably inserted. Further, on the Z (+) side of the carriage body 61, a carriage guide portion 63 that slidably sandwiches a carriage guide plate 28 spanned between the left side frame 25 and the right side frame 26 is provided. Therefore, the carriage 60 is supported in a state in which it can reciprocate between the left side frame 25 and the right side frame 26 in the Y direction.

  As shown in FIG. 5, the recording head holding unit 64 holds the recording head 51 in a posture in which the recording wire protrudes in the Z (−) direction. The recording head 51 is attached with fastening parts such as screws. The recording head holding portion 64 includes a ribbon guide 66 having slopes on which the ink ribbon 84 slides on both sides in the Y direction of an opening (not shown) where a nose portion in which the recording wire of the recording head 51 is accommodated is exposed.

  The carriage moving mechanism 70 includes a carriage drive motor, a pair of pulleys, and a carriage drive belt that is an endless belt (all not shown). The pair of pulleys are respectively arranged on both sides of the main frame 24 in the Y direction, and one of them is connected to the carriage drive motor via a gear train. A carriage drive belt is stretched around the pair of pulleys. The carriage 60 is connected to a part of the endless belt. Therefore, the carriage 60 on which the recording head 51 is mounted is supported on the carriage shaft 27 and the carriage guide plate 28 by the forward and reverse operations of the carriage drive motor, and between the left side frame 25 and the right side frame 26 in the Y direction. Can be moved back and forth.

  The platen 21 is provided at a position facing the scanning area of the recording wire of the recording head 51 mounted on the carriage 60 with the conveyance path 32 interposed therebetween. The platen 21 is a flat platen having a plane extending along the scanning direction of the carriage 60. The platen 21 defines a recording position by the recording head 51.

  As shown in FIG. 5, the ribbon feed mechanism 75 has a ribbon drive transmission unit 77 including a ribbon drive shaft 76. The ribbon drive transmission unit 77 is composed of a plurality of gears including a one-way clutch, and obtains power from the drive pulley of the carriage moving mechanism 70 to rotate the ribbon drive shaft when any of the carriages 60 moves. A ribbon cassette 80 is attached to the ribbon feeding mechanism 75.

  As shown in FIG. 5, the ribbon cassette 80 is covered with a cassette case 81 and includes a long endless ink ribbon 84 impregnated with ink and a ribbon feeding roller pair 85. At this time, the ribbon feeding roller pair 85 holds a part of the ink ribbon 84. When the ribbon cassette 80 is set in the ribbon feed mechanism 75, the ribbon drive shaft 76 of the ribbon drive transmission unit 77 and either roller of the ribbon feed roller pair 85 of the ribbon cassette 80 are fitted. At this time, the ink ribbon 84 exposed in a state of being stretched from an arm portion (not shown) of the ribbon cassette 80 is wound in a slidable state on the side of the recording head 51 from which the recording wire protrudes.

  The ribbon feeding mechanism 75 having such a configuration rotates the rollers of the ribbon feeding roller pair 85 in the ribbon cassette 80 when the carriage 60 moves in either direction, so that the ink ribbon 84 is removed from the cassette case 81. Sequential feeding can be performed while sliding the recording wire of the recording head 51 to the protruding portion.

  The printer 10 having the above-described configuration can transport the recording medium supplied from the supply port 15 or the supply / discharge port 14 in an arbitrary direction along the transport path 32 by the recording medium transport mechanism 30. Then, when the recording medium reaches the position of the platen 21 of the recording mechanism 50, the carriage 60 having the recording head 51 mounted thereon is moved by the carriage moving mechanism 70 in a direction intersecting the recording medium conveyance direction. The recording wire can be selectively projected through the ink ribbon 84 of the ribbon cassette 80 to record information on the recording surface of the recording medium. Thereafter, the recording medium on which the information is recorded is discharged from the supply / discharge port 14 by the recording medium transport mechanism 30 and placed on the recording medium placement surface 17 of the recording medium guide 16.

(About the recording medium transport mechanism)
Here, the recording medium transport mechanism, specifically, the first transport roller pair and the second transport roller pair will be described with reference to FIGS. FIGS. 6A and 6B are diagrams for explaining a method of attaching the feed roller group, and FIGS. FIGS. 7A and 7B are schematic diagrams illustrating the shaft support member. FIG. 7A is a schematic view of the first shaft support member in the first transport roller pair as viewed from the Y direction, and FIG. 7B is a second view of the second transport roller pair. It is the schematic diagram which looked at the biaxial support member from the X direction. 6 and 7 indicate the same directions as the X, Y, and Z directions shown in FIG.

  As shown in FIGS. 3 and 5, the first transport roller pair 35 includes a feed roller set 36 as a main driving roller set and a press roller 37 as a driven roller. The feed roller set 36 includes a plurality of cylindrical feed rollers 38 made of an elastic body such as rubber, and a roller holding shaft 39 penetrating the axial direction of each feed roller 38 so as to cross the transport path 32. Are provided above the transport path 32 in the Z direction, that is, on the recording surface side of the recording medium.

  As shown in FIG. 6, a molded product such as plastic is suitably applied to the roller holding shaft 39, and a driving gear 40 and a latch receiving portion 47 are formed at one end thereof. The locking receiving portion 47 is formed with an annular slope portion 48 whose diameter gradually increases in the end direction and an annular hook receiving portion 49 that is lowered by one step from the apex portion of the annular slope portion 48. A locking portion 45 is provided on one of the left side frame 25 and the right side frame 26 as two wall portions of the main body frame 22 on which the roller holding shaft 39 is bridged, and a bearing 29 (see FIG. 3) is provided on the other side. ) Is provided. The locking portion 45 has an engagement hole 45a, and a rod-like hook portion 46 having a hook portion at the tip end utilizing the elasticity of plastic or the like extends inward from the edge portion of the engagement hole.

  When assembling the feed roller set 36 to the main body frame 22, as shown in FIGS. 6A to 6B, the feed roller set 36 is assembled while sliding in the Y direction. That is, the roller holding shaft 39 is fitted into the other bearing 29 and the engagement hole 45a and is slid in the Y direction. Then, the hook portion 46 provided in the locking portion 45 bends in the Z direction along the annular inclined surface portion 48 of the locking receiving portion 47 of the roller holding shaft 39 that slides in the Y direction. Thereafter, when the hook portion 46 exceeds the apex portion of the annular slope portion 48 as the roller holding shaft 39 slides, the hook portion 46 falls and is fixed to the annular hook receiving portion 49 that has been lowered one step.

  As shown in FIG. 3 and FIG. 7A, at this time, the roller holding shaft 39 of the feed roller set 36 is moved in the Z (+) direction by the first shaft support member 55 having a central portion in the Y direction as a shaft support member. To be supported in the Z (−) direction. The first shaft support member 55 has an arcuate sliding surface 55 a on which the outer periphery of the roller holding shaft 39 slides, and is fixed to the main frame 24 of the main body frame 22. The arcuate sliding surface 55a of the first shaft support member 55 reduces the bending of the roller holding shaft 39 in the Z (+) direction, and the roller holding shaft 39 is connected to the left side frame 25 and the right side of the main body frame 22. It has a function as a guide when incorporated in the frame 26.

  The presser roller 37 is a cylindrical roller with support columns extending on both sides made of plastic or the like, and the feed roller group 36 via the transport path 32 by an urging force of an elastic member such as a bar spring from below in the Z direction. It arrange | positions so that it may press on each feed roller 38 of each. The feed roller set 36 is connected to a feed motor (not shown) via a drive gear 40 (see FIG. 6) of the roller holding shaft 39, and rotates by obtaining a drive force from the feed motor. Therefore, the recording medium sandwiched between the feed roller 38 and the press roller 37 of the feed roller group 36 can be transported along the transport path 32 in any forward and reverse directions.

  Next, the second transport roller pair 41 will be described. As shown in FIGS. 3 and 5, the second transport roller pair 41 is arranged in the X (+) direction of the first transport roller pair 35, and is a feed roller set as a main driving roller similar to the first transport roller pair 35. 36 and a presser roller 37 as a driven roller similar to the first transport roller pair 35. The second transport roller pair 41 has the same components as the first transport roller pair 35 but is different in configuration.

  The feed roller set 36 includes a plurality of cylindrical feed rollers 38 made of an elastic body such as rubber, and a roller holding shaft 39 penetrating the axial direction of each feed roller 38 so as to cross the transport path 32. Are provided on the upper side of the transport path 32 in the Z direction, that is, on the back side of the recording medium, that is, on the opposite side of the first transport roller pair 35 and the transport path 32.

  The roller holding shaft 39 shown in FIG. 6 is formed with a drive gear 40 and a latch receiving portion 47 at either one end, similarly to the first transport roller pair 35. The locking receiving portion 47 is formed with an annular slope portion 48 whose diameter gradually increases in the end direction and an annular hook receiving portion 49 that is lowered by one step from the apex portion of the annular slope portion 48. A locking portion 45 is provided on one of the left side frame 25 and the right side frame 26 of the main body frame 22 on which the roller holding shaft 39 is bridged, and a bearing 29 is provided on the other. The locking portion 45 has an engagement hole 45a, and a rod-like hook portion 46 having a hook portion at the tip end utilizing the elasticity of plastic or the like extends inward from the edge of the engagement hole 45a.

  The feed roller set 36 of the second transport roller pair 41 having the above-described structure is assembled to the main body frame 22 in the same manner as the feed roller set 36 of the first transport roller pair 35.

  As shown in FIG. 3 and FIG. 7B, at this time, the roller holding shaft 39 of the feed roller set 36 of the second transport roller pair 41 is a second shaft support member 56 having a central portion in the Y direction as a shaft support member. Is supported from the Z (−) direction. The second shaft support member 56 has a planar sliding surface 56a on which a part of the outer periphery of the roller holding shaft 39 slides, and serves as a protrusion protruding in the Z (+) direction from the transport path 32 of the printer body 20. Is formed. The planar sliding surface 56a of the second shaft support member 56 receives the roller holding shaft 39 and reduces bending in the Z (−) direction, and the roller holding shaft 39 is connected to the left side frame 25 of the main body frame 22 and It has a function as a guide when incorporated in the right side frame 26.

  The press roller 37 is a cylindrical roller with support columns extending on both sides made of plastic or the like, and is attached to a press roller attachment member 58 formed of plastic or the like shown in FIG. 5, for example. The presser roller mounting member 58 is provided to be rotatable in the direction of arrow A in FIG. In a closed state of the presser roller mounting member 58, the presser roller 37 is pressed against each feed roller 38 of the feed roller set 36 via the transport path 32 by an urging force of an elastic member such as a bar spring from above in the Z direction. Is arranged. In the open state of the presser roller mounting member 58, the feed roller 38 and the presser roller 37 of the feed roller set 36 can be separated from each other, and a part of the transport path 32 can be opened.

  The feed roller set 36 is connected to a feed motor (not shown), and rotates by obtaining a driving force from the feed motor. Therefore, the recording medium sandwiched between the feed roller set 36 and the pressing roller 37 can be transported along the transport path 32 in any direction. The recording medium guide 16 is disposed in the X (+) direction of the second transport roller pair 41, that is, in the supply / discharge port 14.

  The recording medium conveyance mechanism 30 having the above-described configuration is configured to convey the fanfold paper F as a recording medium supplied from the supply port 15 by the tractor unit 33, the first conveyance roller pair 35, and the second conveyance roller pair 41. Can be discharged in the X (+) direction and discharged onto the recording medium mounting surface 17 of the recording medium guide 16 of the supply / discharge port 14. Further, the cut sheet T guided and supplied by the recording medium guide 16 of the supply / discharge port 14 is moved in the X (−) direction along the conveyance path 32 by the first conveyance roller pair 35 and the second conveyance roller pair 41. It can be conveyed forward and backward in the X (+) direction and discharged again onto the recording medium placement surface 17 of the recording medium guide 16 of the supply / discharge port 14.

(Regarding recording medium transport operation)
(For fanfold paper)
Here, a recording medium conveyance operation using the above-described recording medium conveyance mechanism will be described. First, the case where the fanfold paper F shown in FIG. 2 is used as a recording medium, supplied from the supply port 15 of the printer 10 shown in FIG. 1, information is recorded and discharged from the supply / discharge port 14 will be described.

  As shown in FIGS. 4 and 5, the fanfold paper F stacked outside the printer 10 is sequentially drawn out, supplied from the supply port 15, and set in the tractor unit 33. Thereafter, the tractor unit 33 is driven, and the fanfold paper F is transported in the X (+) direction along the transport path 32 to reach the position of the first transport roller pair 35. The fanfold paper F reaching the first transport roller pair 35 is further transported and reaches the recording position of the recording mechanism 50, that is, the scanning position of the recording head 51.

  The first transport roller pair 35 is operated to further transport the fanfold paper F and advance in the direction of the second transport roller pair 41. Since the first recording medium detection device 52 is provided in the vicinity of the second transport roller pair 41, if the leading edge detection signal of the fanfold paper F by the first recording medium detection device 52 is confirmed, the fanfold paper F is It can be confirmed that the second conveyance roller pair 41 has been reached and that the second conveyance roller pair 41 has been sandwiched. Thereafter, desired information is recorded on the recording surface of the fanfold paper F conveyed in the X direction while the recording head 51 of the recording mechanism 50 is reciprocated in the Y direction. The fanfold paper F on which information is recorded is further transported by the recording medium transport mechanism 30, discharged from the supply / discharge port 14 of the printer 10, and mounted on the recording medium mounting surface 17 of the recording medium guide 16.

(In the case of cut paper)
Next, a case where the cut sheet T shown in FIG. 2 is used as a recording medium, supplied from the supply / discharge port 14 of the printer 10 shown in FIG. Since the cut sheet T may be processed one by one, it may be supplied from the front supply / discharge port 14 operated by the operator and discharged to the front supply / discharge port 14 as well. Further, as the cut sheet T, many types such as cut sheets having different thicknesses, a booklet in which sheets are stacked and bound on one side, and a sheet in which a plurality of sheets are stacked in a single sheet form are applied.

  The cut sheet T is inserted along the recording medium placement surface 17 of the recording medium guide 16 provided at the supply / discharge port 14 of the printer 10. In the printer 10, the leading end portion of the cut sheet T is inserted into contact with the detection lever 53 of the first recording medium detection device 52, and the detection lever 53 swings to move the leading end position of the cut sheet T. It is detected that the slip sheet T has been inserted. Using this detection as a trigger, the second transport roller pair 41 is driven to transport the inserted cut sheet T in the X (−) direction along the transport path 32. The cut sheet T to be conveyed advances in the direction of the first conveying roller pair 35 through the recording position of the recording mechanism 50, that is, the position of the platen 21.

  In this state, the second transport roller pair 41 is operated to further transport the cut sheet T and reach the position of the first transport roller pair 35. Since the second recording medium detection device 59 is provided in the vicinity of the first transport roller pair 35, if the leading edge detection signal of the cut sheet T by the second recording medium detection device 59 is confirmed, the cut sheet T It can be confirmed that the first conveying roller pair 35 has been reached and that the first conveying roller pair 35 has been sandwiched.

  While the recording head 51 of the recording mechanism 50 is reciprocated in the Y direction, desired information is recorded on the recording surface of the cut sheet T conveyed in the X (−) direction. The cut sheet T on which information is recorded is transported in the X (+) direction, which is the reverse direction, by the first transport roller pair 35 and the second transport roller pair 41 of the recording medium transport mechanism 30. The cut sheet T on which information is recorded is discharged from the supply / discharge port 14 of the printer 10 and is mounted on the recording medium mounting surface 17 of the recording medium guide 16.

Hereinafter, effects of the present embodiment will be described.
(1) The above-described printer 10 uses the recording medium having a different thickness and the roller holding shaft 39 of the feed roller group 36 is rotated even if the pressure (reaction force) between the feed roller group 36 and the press roller 37 changes. The first shaft support member 55 or the second shaft support member 56 can be supported in a direction against the reaction force at a predetermined portion in the direction. Therefore, excessive deflection of the roller holding shaft 39 can be reduced. As a result, it is possible to reduce a change in pressing force of the pair of the feeding rollers 38 and the pressing roller 37 and to reduce a difference in conveying force in the width direction of the recording medium. Therefore, stable conveyance of the recording medium can be realized even with recording media of different types and thickness.

  (2) In the printer 10 described above, the presser roller 37 is individually pressed against the feed roller 38 by an elastic member. Therefore, the pressing force of the set of each feed roller 38 and presser roller 37 can be set to a predetermined pressure. As a result, even when a deflection occurs in the axial direction of the roller holding shaft 39, it is possible to reduce variations in the pressing force of the pairs of the feeding rollers 38 and the pressing rollers 37. Therefore, the difference in feed force in the width direction of the recording medium can be reduced, and stable running of the recording medium can be realized.

  (3) The above-described printer 10 has, as a recording medium, a fanfold paper F composed of a plurality of sheets, a single sheet having different thicknesses, a booklet in which sheets are stacked and bound on one side, a single sheet in which a plurality of sheets are stacked, and the like Information can be recorded on various types of recording media. Therefore, the printer 10 with higher versatility can be provided.

  As mentioned above, although embodiment of this invention was described, various deformation | transformation can be added with respect to the said embodiment in the range which does not deviate from the meaning of this invention.

  DESCRIPTION OF SYMBOLS 10 ... Printer, 12 ... Exterior case, 14 ... Supply / discharge port, 15 ... Supply port, 16 ... Recording medium guide, 20 ... Printer main body, 21 ... Platen, 30 ... Recording medium conveyance mechanism, 32 ... Conveyance path, 33 ... Tractor Unit: 35 ... first conveying roller pair, 36 ... feed roller group as main driving roller group, 37 ... pressing roller as driven roller, 38 ... feed roller, 39 ... roller holding shaft, 41 ... second conveying roller pair, 45 ... Locking portion 47. Lock receiving portion 50... Recording mechanism 51... Recording head 55. First shaft support member 56. Second shaft support member 60. Ribbon feed mechanism, 80 ... ribbon cassette, F ... fanfold paper, T ... cut sheet paper.

Claims (7)

A recording medium transport mechanism for transporting a recording medium on which information is recorded along a transport path having a planar area,
Consisting of a plurality of feed rollers and a roller holding shaft that holds the feed rollers at a predetermined interval, and a main driving roller set that rotates by obtaining a driving force;
A rotatable driven roller that is pressed with a predetermined pressure individually corresponding to the feed roller,
The recording medium, wherein the roller holding shaft of the main driving roller set is supported in a direction against a reaction force generated by the feeding roller and the driven roller by a shaft support member at a predetermined portion in the axial direction. Transport mechanism. The plurality of driven rollers are respectively arranged at positions corresponding to the feed rollers,
The recording medium transport mechanism according to claim 1, wherein each driven roller is pressed by an elastic member and pressed by the feed roller. At least two main driving roller groups are arranged at a predetermined interval in the conveyance direction of the recording medium,
Any one of the main driving roller sets is disposed on one surface side of the recording medium,
The recording medium transport mechanism according to claim 1, wherein the other main driving roller set is disposed on the other surface side of the recording medium. The roller holding shaft of any one of the main driving roller sets is supported by the shaft support member having a projection having a surface that supports the sliding while sliding the shaft surface,
The recording medium conveyance according to claim 3, wherein the roller holding shaft of the other main driving roller set is supported by the support member having an arcuate sliding surface that is supported while sliding the circumference of the shaft. mechanism. The roller holding shaft of the main driving roller set is bridged between two wall portions arranged at opposite positions,
The latch receiving part provided in the one edge part direction of the said roller holding shaft is latched by the latch part provided in one of the two said wall parts. The recording medium transport mechanism according to any one of the above. The locking portion of the wall portion has a hook portion, and is a rod-like member that bends in the radial direction of the roller holding shaft,
The locking receiving portion of the roller holding shaft includes an annular slope portion in which the hook portion slides and the rod-shaped member bends in a radial direction of the roller holding shaft in the axial movement of the roller holding shaft, and the annular The recording medium conveyance mechanism according to claim 5, further comprising an annular hook receiving portion that is lowered by one step from an apex portion of the slope portion. The recording medium transport mechanism according to any one of claims 1 to 6, wherein a recording medium on which information is recorded is transported along a transport path having a planar area.
A carriage on which a recording head having a plurality of recording wires is mounted,
A printer that records information on the recording medium by selectively projecting the recording wire of the recording head while moving the carriage in a direction intersecting the conveyance direction of the recording medium.

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