JP5854105B2 - printer - Google Patents

Description

  The present invention relates to a printer including a plurality of sets of print heads that perform printing on each surface of a recording medium such as a check, and more particularly to a printer including a mechanism that can appropriately set the platen gap of each print head.

  As this type of printer, there is known a printer having two sets of print heads for performing writing on the front and back of a check together with a magnetic head for reading magnetic ink characters printed on the check. Patent Documents 1 and 2 disclose such a printer (medium processing apparatus, composite processing apparatus).

JP 2000-43339 A JP 2010-20809 A

  Here, a front print head and a back print head for printing on the front and back sides of a recording medium such as a check are mounted on each apparatus frame portion located on both sides of the conveyance path of the recording medium. On the other hand, the platen that defines the printing position of the front print head is mounted on the device frame on the end print head side, and the platen of the end print head is on the device frame portion on the front print head side. Installed.

  The platen gap in both print heads is as narrow as 0.5 mm or less, for example, so that such a narrow gap can be obtained accurately, the two sets of print heads and platens mounted on different apparatus frame portions are accurately opposed to each other. Placement is not as easy as with a single printhead, platen. In particular, when an external force is applied, both device frame parts are displaced, and both platen gaps are likely to change in different states. Compared to the case where platen gap adjustment is performed at one place, the platen gap Is difficult to adjust.

  On the other hand, even if the gap between the print head and the platen is constant, if a recording medium having a different thickness is conveyed, the platen gap between the printing surface of the recording medium and the print head changes, resulting in a decrease in print quality. Such harmful effects occur. Conventionally, there is a problem that the platen gaps of both print heads cannot be made to follow according to the thickness of the recording medium.

  In view of the above, an object of the present invention is to propose a printer having a platen gap adjustment function capable of holding a plurality of platen gaps constant.

In order to solve the above problems, the printer of the present invention provides:
Body frame,
A first head unit on which a first print head, a first medium transport roller, and a second platen are mounted and rotatably supported by the main body frame ;
First platen down, the second media transportation roller, and is mounted a second print head, a second head unit supported by the body frame so as to be movable in approaching and leaving directions with respect to the first media transportation roller ,
Provided between the second head unit and the main body frame, the second head unit is urged in a direction approaching the first medium transport roller to turn the second medium transport roller to the first medium transport roller. It includes a biasing member pressed is, a,
In the second head unit, the first print head and the first platen are opposed to each other, the second print head and the second platen are opposed to each other, and the second medium conveyance roller is in contact with the first medium conveyance roller. It is placed at the contact point,
When the distance between the first medium transport roller and the second medium transport roller changes due to the thickness of the medium transported by the first medium transport roller and the second medium transport roller, the first head unit is moved with respect to the first head unit. The relative position of the second head unit changes .

  In the present invention, the second head unit is movable, and the second medium transport roller mounted on the second head unit by the biasing member is replaced with the first medium transport roller mounted on the fixed first head unit. Therefore, the relative positions of both units are defined by the first and second medium transport rollers. Even when both units are displaced due to an external force or the like, the urging force of the urging member maintains the contact state of the first medium conveyance roller and the second medium conveyance roller, and the relative positions of both units are constant. Therefore, the platen gap of each of the first and second print heads is kept constant.

  Further, the distance between the first medium transport roller and the second medium transport roller changes following the thickness of the recording medium transported between them. Thereby, the relative positions of the first head unit and the second head unit defined by the contact of these rollers change. As a result, the distance between the first print head on the first head unit side and the first platen on the second head unit side changes following the thickness of the conveyed recording medium. Similarly, the distance between the second print head on the second head unit side and the second platen on the first head unit side changes. Accordingly, since the platen gap increases according to the thickness of the recording medium to be conveyed, the distance between the head unit and the recording medium is maintained at a certain value or more.

  Here, the second medium transport roller and the second platen may be mounted on a member different from the second head unit, and the first head unit and the second head unit may be positioned via the member.

In this case, the printer of the present invention is
Body frame,
A first head unit on which a first print head, a first medium transport roller, and a second platen are mounted and rotatably supported by the main body frame ;
It is mounted a second media transportation roller and a first platen, a movable member attached to said body frame so as to be movable in approaching and leaving directions with respect to the first media transportation roller,
It is mounted a second print head, a second head unit supported by the movable main body frame toward and away direction with respect to the first media transportation roller,
Provided between the moving member and the second head unit, urging the moving member in a direction approaching the first medium transport roller and pressing the second medium transport roller against the first medium transport roller A first biasing member,
A second biasing member provided between the second head unit and the main body frame and biasing the second head unit in a direction approaching the first medium transport roller and pressing the second head unit against the moving member; , has a,
In the first head unit, the moving member, and the second head unit, the first print head and the first platen face each other, the second print head and the second platen face each other, and the first medium It is disposed at a position where the second medium transport roller comes into contact with the transport roller,
When the distance between the first medium transport roller and the second medium transport roller changes due to the thickness of the medium transported by the first medium transport roller and the second medium transport roller, the first head unit is moved with respect to the first head unit. The relative position of the moving member changes .

  In the present invention, the second medium transport roller mounted on the moving member is pressed against the first medium transport roller mounted on the first head unit by the first biasing member. The relative position between the first head unit and the moving member is defined by the contact between the first medium conveying roller and the second medium conveying roller, and is mounted on the first print head and the moving member mounted on the first head unit. The relative position with respect to the first platen is defined, and the platen gap in the first print head is defined.

  Further, the second head unit is pressed against the moving member positioned with respect to the first head unit by the second urging member, and the relative movement of the second head unit by the contact between the moving member and the second head unit is increased. A position is defined. Accordingly, the relative positions of the first head unit and the second head unit are defined via the moving member, and the second print head mounted on the second head unit and the second platen mounted on the first head unit are defined. The platen gap in the second print head is defined.

  Thus, the platen gap on the first print head side is adjusted between the first head unit and the moving member, and the platen gap on the second print head side is adjusted between the first head unit and the second head unit. Is done. Compared with the case where the platen gap adjustment between the first head unit and the second head unit is performed using the two members, the platen gap adjustment can be easily performed by using the three members.

  Further, when any of the first head unit, the moving member, and the second head unit is displaced by an external force or the like, for example, when the first head unit is displaced, the moving member is displaced following the displacement, and the moving member The second head unit is displaced following this displacement. Accordingly, since the relative positional relationship between the three portions is always kept constant, the platen gap defined by the first print head and the first platen and the platen gap defined by the second print head and the second platen are also constant. Retained.

  Further, the relative positions of the first head unit and the moving member are defined by the contact of the first medium transport roller and the second medium transport roller. The interval between these rollers changes following the thickness of the recording medium being conveyed. Thereby, the relative position of the moving member with respect to the first head unit defined by the contact of these rollers changes, and the position of the second head unit defined by the moving member is also displaced. As a result, the distance between the first print head on the first head unit side and the first platen on the moving member side changes following the thickness of the conveyed recording medium, and the second print head on the second head unit side changes. Then, the interval between the second platens on the first head unit side changes. Accordingly, since the platen gap increases according to the thickness of the recording medium to be conveyed, the distance between the head unit and the recording medium is maintained at a certain value or more.

  Here, a rotating member that can rotate around a predetermined rotation fulcrum is used as the moving member, and the first urging member extends between the rotating member and the second head unit. A handed tension coil spring can be used. By appropriately setting the spanning position of the tension coil spring and the shape of the rotating member, the moving member and the second head unit can be held against each other by the tension spring force. The backlash can be suppressed.

  Next, in the printer of the present invention, when viewed along the recording medium conveyance direction via the nip portion of the first medium conveyance roller and the second medium conveyance roller, the nip portion is sandwiched between the first medium conveyance roller and the first medium conveyance roller. One of the print head and the second print head is preferably located on the upstream side in the transport direction, and the other is located on the downstream side in the transport direction. In the transport direction, if the distance from the nip portion to the first print head and the distance from the nip portion to the second print head are greatly different, the opening amount of the first and second medium transport rollers depending on the media thickness is Changes in the platen gap on the side of the first print head and the platen gap on the side of the second print head are greatly different. By disposing the first and second print heads on the upstream side and the downstream side of the nip portion along the transport direction, the difference in change of both platen gaps with respect to the medium thickness can be reduced.

  Next, in the printer of the present invention, the first print head and the second print head are dot impact heads, and each of the first head unit and the second head unit includes an ink ribbon cassette mounting portion. It can be configured. Since the second head unit is movable, when the second head unit is forcibly moved away from the first head unit side, the second print head is located between the first print head and the first platen. And the second platen are widened, so that the operation of mounting the ink ribbon between them can be easily performed.

  In the printer of the present invention, the second medium transport roller mounted on the movable second head unit is pressed against the first medium transport roller on the first head unit side to define the relative position between them. Yes. By maintaining the contact state of the first and second medium transport rollers by the urging member, the platen gap in the first print head and the second print head can be maintained constant, and the disturbance resistance of the platen gap can be improved. Further, the distance between the first and second medium transport rollers is displaced according to the thickness of the transported recording medium, and the platen gap in the first and second print heads changes, so that the thickness of the transported recording medium is increased. Accordingly, since the platen gap increases, the distance between the head unit and the recording medium is maintained at a certain value or more.

1 is an external perspective view of a check processing device according to an embodiment of the present invention. It is a side view which shows the internal mechanism part of a check processing apparatus. It is a perspective view which shows the internal mechanism part of a check processing apparatus. It is a perspective view which shows the internal mechanism part of a check processing apparatus. It is explanatory drawing which shows the platen gap adjustment mechanism of a check processing apparatus.

  A check processing apparatus (printer) according to an embodiment of the present invention will be described below with reference to the drawings.

(overall structure)
FIG. 1 is an external perspective view of a check processing apparatus. The check processing device 1 includes a main body case 2 formed in a substantially rectangular parallelepiped shape as a whole. A medium insertion port 3 for inserting a check (not shown) as a recording medium is provided at a predetermined width along the apparatus width direction at a portion near the left side of the front surface of the main body case 2. In the central portion of the upper surface of the main body case 2 in the front-rear direction of the apparatus, a medium discharge port 4 for discharging a check after processing is provided with a predetermined width along the apparatus width direction. Between the medium insertion port 3 and the medium discharge port 4, a medium conveyance path 5 through which a check is conveyed is formed. The medium transport path 5 is formed so as to bend upward and extend from the medium insertion port 3 to the rear of the apparatus. Further, the medium transport path 5 is opened on the left side surface of the main body case 2.

  On the upper surface of the main body case 2, the front side of the medium discharge port 4 is covered with a front cover 6. An operation panel 7 is provided at the front end portion of the front cover 6. An opening 8 is provided at the rear end portion of the upper surface of the main body case 2, and an opening / closing lid 9 for opening and closing the opening 8 is attached. The opening / closing lid 9 is attached to the main body case 2 so as to be rotatable about the rear end portion.

  Here, the part covered by the front cover 6 in the check processing device 1 is an openable / closable opening / closing unit 10, and the front is centered on a first rotation center line CL <b> 1 extending in the device width direction at the lower end of the front side. It is possible to open it. When the opening / closing unit 10 is opened, the medium transport path 5 formed between the opening / closing unit 10 and the apparatus main body side is switched to the open state. The opening / closing unit 10 can be opened and closed by pulling the operation lever 11 with the operation end 11a exposed to the upper surface portion of the right end.

(Internal structure)
FIG. 2 is a side view showing the internal mechanism part of the check processing apparatus 1 with the main body case 2 removed, and FIG. 3 is a perspective view of the internal mechanism part as seen from the rear side of the apparatus slightly from the side. FIG. 4 is a perspective view of the internal mechanism as viewed from the front side of the apparatus. Referring to these drawings, the internal mechanism 12 of the check processing device 1 includes an apparatus main body frame 13, and the apparatus main body frame 13 includes a head unit 14 for writing that constitutes the opening / closing unit 10. In addition, an endorsement head unit 15 and a platen lever unit 16 are mounted.

  The front writing head unit 14 and the end writing head unit 15 are disposed to face each other with a vertical conveyance path portion 5c extending above the apparatus in the medium conveyance path 5 interposed therebetween, and the front writing unit 14 is located on the front side of the apparatus. . Between the front writing head unit 14 and the apparatus main body frame 13, a horizontal conveyance path portion 5a extending linearly from the front side of the apparatus to the rear side and a curved conveyance path curved upward and connected to the vertical conveyance path portion 5c. The front head unit 14 is located on the upper side of the apparatus. The front writing head unit 14 is supported by the apparatus main body frame 13 such that the lower end portion on the front side of the apparatus is rotatable about the rotation center line CL1 toward the front of the apparatus. The lining head unit 15 is supported by the apparatus main body frame 13 so as to be slidable in the longitudinal direction of the apparatus.

  A magnetic head 17 for reading the magnetic ink characters printed on the check is disposed in the horizontal conveyance path portion 5 a of the medium conveyance path 5. The magnetic head 17 is disposed on the upper side of the horizontal conveyance path portion 5a with the magnetic gap thereof directed downward.

  On the lower side of the vertical conveyance path portion 5c in the medium conveyance path 5, an endorsement print head 18 for printing on the back side of the check and an endorsement platen 19 are disposed oppositely across the vertical conveyance path portion 5c. Yes. The print head 18 for endorsing is a serial impact dot matrix (SIDM) print head that performs printing by hitting a recording wire against an ink ribbon and causing ink on the ink ribbon to adhere to a check. The endorsement print head 18 is mounted on the endorsement head unit 15 disposed on the rear side of the vertical conveyance path portion 5c, and the endorsement platen 19 is mounted on the front writing head unit 14. .

  At the upper end portion of the vertical conveyance path portion 5c, a front print head 20 for printing on the surface of the check and a front platen 21 are arranged opposite to each other with the vertical conveyance path portion 5c interposed therebetween. The front print head 20 is a SIDM print head similar to the back print head 18 and is mounted on the front head unit 14. The front platen 21 is mounted on the platen lever unit 16.

  On the other hand, a pair of medium transport rollers 22 and 23 for transporting a check via a reading position by the magnetic head 17 are arranged in contact with each other at a boundary portion between the horizontal transport path portion 5a and the curved transport path portion 5b. Yes. In addition, the pair of first and second medium transport rollers 24 and 25 that transport the check are in contact with each other at approximately the middle position between the print head 18 for writing and the print head 20 for front writing in the vertical transport path portion 5c. Is arranged. The first medium conveyance path roller 24 located on the front side of the apparatus is mounted on the front writing head unit 14 in a rotatable state, and the second medium conveyance roller 25 located on the rear side of the apparatus is rotatable on the platen lever unit 16. It is mounted in the state of.

  The head writing head unit 14 is provided with an ink ribbon cassette mounting portion 27 in which an ink ribbon cassette 26 containing an ink ribbon is detachably mounted (the ink ribbon cassette 26 is omitted in FIG. 4). is there.). An ink ribbon (not shown) fed out from the mounted ink ribbon cassette 26 is set so as to pass between the front print head 20 and the front platen 21. Similarly, the writer head unit 15 also includes an ink ribbon cassette mounting portion 29 in which the ink ribbon cassette 28 is mounted in a removable state. An ink ribbon (not shown) fed out from the mounted ink ribbon cassette 28 is set so as to pass between the print head 18 for endorsing and the platen 19 for endorsing.

  Next, the platen lever unit 16 is bridged in the apparatus width direction between the left and right platen levers 31 and 32 disposed on both sides in the apparatus width direction and the upper end portions of these platen levers 31 and 32. And a connecting plate 33. The connecting plate 33 has a fixed width and is arranged facing the front of the apparatus, and is attached to the front surface of the connecting plate 33 so that the front platen 21 faces the head surface of the front print head 20. It has been.

  The left and right platen levers 31 and 32 have the same shape and are arranged symmetrically. The platen lever 31 will be described. The platen lever 31 has a fixed width horizontal arm portion 31a extending linearly in the front-rear direction of the device, and is bent substantially perpendicularly from the rear end of the horizontal arm portion 31a to the upper direction of the device. And a vertical arm portion 31b having a certain width, and has a letter “L” shape as a whole. The horizontal arm portions 31a are arranged along both sides in the apparatus width direction of the apparatus main body frame 13 located on the lower side of the writing head unit 14, and the end portions on the front side of the apparatus are arranged in the apparatus width direction. It is attached to the apparatus main body frame 13 so that it can be rotated up and down around the extending rotation center shaft 34. The vertical arm portions 31b are arranged along the both sides of the head unit 15 for writing in the device width direction at a portion of the medium conveyance path 5 on the rear side of the apparatus with respect to the vertical conveyance path portion 5c. The second medium transport roller 25 is bridged in the apparatus width direction between the portions below the connecting plate 33 in the vertical arm portion 31b. Since the other platen lever 32 has the same configuration, the description thereof is omitted.

  Here, a tension coil spring 35 is stretched between the left and right platen levers 31 and 32 and the lining head unit 15 in a tensioned state. The platen lever 31 will be described. As shown in FIG. 2, a spring hook 31c formed at the lower end portion of the vertical arm portion 31b and a portion on the side of the upper lining head unit 15 on the rear side. A tension coil spring 35 for the lever is bridged between the spring hook 15a. Due to the tension spring force of the tension coil spring 35, the platen lever unit 16 is pulled in a direction to rotate upward about the rotation center axis 34, and the second medium transport roller 25 mounted there is the first medium transport roller 25 on the front side of the apparatus. It is in contact with the medium transport roller 24 with a predetermined pressing force. Similarly, a tension coil spring is disposed on the platen lever 32 side.

  Further, an abutting piece 15 b protruding outward is formed on the left side surface portion of the lining head unit 15. The contact piece 15b and the rear end surface 31d of the vertical arm portion 31b of the platen lever 31 are held in contact with each other by the tension spring force of the lever tension coil spring 35. The same configuration is also provided on the platen lever 32 side.

  Further, the endorsement head unit 15 is pulled forward of the apparatus by unit tension coil springs 36 arranged in a tension state in the apparatus front-rear direction on both sides in the apparatus width direction. As shown in FIG. 2, the rear end of the unit tension coil spring 36 is hung on spring hooks 15 c formed on the left and right sides of the lining head unit 15, and the front end of the unit is attached to the main body case 13. It is hung on a spring hook 13a formed on the left and right. Due to the tension spring force of the unit tension coil spring 36, the lining head unit 15 is pressed against the platen lever unit 16 via the left and right contact pieces 15b.

(Platen gap adjustment mechanism)
FIG. 5 is an explanatory view showing components extracted from the platen gap adjusting mechanism in the check processing apparatus 1. The platen gap adjustment mechanism of the front print head 20 and the back print head 18 will be described mainly with reference to FIG. In this example, the second medium transport roller 25 mounted on the platen lever unit 16 is pressed against the first medium transport roller 24 mounted on the front writing head unit 14 by the lever tension coil spring 35 (nip). Part C). By the contact of the first medium transport roller 24 and the second medium transport roller 25, the relative position between the head unit 15 for writing and the platen lever unit 16 is defined, and the front writing unit mounted on the head unit 14 for writing is used. The relative position between the print head 20 and the front platen 21 mounted on the platen lever unit 16 is defined, whereby the platen gap in the front print head 20 is defined.

  Further, the end writing head unit 15 is pressed against the platen lever unit 16 positioned with respect to the front writing head unit 14 by a unit tension coil spring 36 (point B). These relative positions are defined by the contact of the writing head unit 15. Accordingly, the relative position of the writing head unit 15 relative to the writing head unit 14 is defined via the platen lever unit 16, and the printing head 18 for writing and the writing head mounted on the writing head unit 15. A relative position between the printing plate 18 and the printing plate 18 for endorsing is defined relative to the platen 19 for writing on the unit 14.

  In this way, the platen gap on the side of the front writing print head 20 is adjusted between the front writing head unit 14 and the platen lever unit 16, and the printing for end printing is performed between the front writing head unit 14 and the back writing head unit 15. The platen gap on the head 18 side is adjusted. Therefore, it is easier to adjust the gap between the front writing head unit 14 and the end writing head unit 15 than when both platen gaps are adjusted.

  Further, when any one of the front writing head unit 14, the platen lever unit 16 and the end writing head unit 15 is displaced by an external force or the like, for example, when the front writing head unit 14 is displaced, the platen lever is followed. The unit 16 is displaced, and the lining head unit 15 is displaced following the displacement of the platen lever unit 16. Accordingly, since the relative positional relationship between the three parts is always kept constant, it is defined by the platen gap defined by the front print head 20 and the front platen 21, and the back print head 18 and the back platen 19. The platen gap is also kept constant, and the disturbance resistance of the platen gap can be improved.

  Further, the relative positions of the front writing head unit 14 and the platen lever unit 16 are defined by the contact of the first medium transport roller 24 and the second medium transport roller 25. The distance between these rollers 24 and 25 changes following the thickness of the check (recording medium) being conveyed. As a result, the relative position of the platen lever unit 16 with respect to the front writing head unit 14 defined by the abutment of these rollers 24 and 25 changes, and the enduring head unit 15 defined by the platen lever unit 16 changes. The position is also displaced. As a result, the distance between the front print head 20 on the front writing head unit 14 side and the front platen 21 on the platen lever unit 16 side changes following the thickness of the conveyed check, and the end writing head unit 15. The distance between the side printing head 18 on the side and the platen 19 on the side of the front writing head unit 14 changes. Therefore, the platen gap in both the print heads 18 and 20 changes following the thickness of the check to be conveyed, and the distance between the head unit and the recording medium is maintained at a certain value or more.

  Further, as the platen lever unit 16, a rotating member that can rotate about the rotation fulcrum A is used, and the platen lever unit 16 and the lining head unit 15 are moved by the tension spring force of the lever tension coil spring 35. They are energized in the direction of pressing each other. As a result, rattling between them can be suppressed, which is effective for keeping the platen gap constant.

  Next, when viewed along the conveyance direction of the check passing through the nip portion C of the first medium conveyance roller 24 and the second medium conveyance roller 25, the nip portion C is sandwiched, and the print head 20 and the end printing are written. The nip portion C is located at a substantially middle position of the printing head 18 for printing. When the distance from the nip C to the front print head 20 and the distance from the nip C to the back print head 18 are greatly different in the transport direction, the first and second medium transport rollers 24 depending on the thickness of the check, With respect to the opening amount of 25, the change in the platen gap on the front print head 20 side and the platen gap on the back print head 18 side are greatly different. By disposing the front print head 20 and the back print head 18 at positions close to the downstream side and the upstream side across the nip portion C along the conveying direction, the difference in change in both platen gaps due to the thickness of the check Can be reduced.

  In addition, in this example, the front print head 20 and the back print head 18 are dot impact heads, between the front print head 20 and the front platen 21, and the back print head 18. It is necessary to mount an ink ribbon between the endorsing platen 19. Since the lining head unit 18 is slidable in the front-rear direction of the apparatus, when it is slid backward against the spring force, it is printed between the printing head 20 for front writing and the platen 21 for writing, and printing for lining. The space between the head 18 and the platen 19 for endorsing is widened, and the operation of mounting the ink ribbon between them can be easily performed.

(Other embodiments)
In the above-described embodiment, the platen lever unit is disposed, and the end writing head unit is positioned through the platen lever unit. It is also possible to adopt a configuration in which the platen lever unit and the lining head unit are integrated. In the printer in this case, the front print head, the first medium transport roller, and the back platen are mounted on the front head unit. Also, the writing head unit has a front platen mounted at a position where it can face the front print head, and a second medium transport roller is mounted at a position capable of contacting the first medium transport roller. A front platen is mounted at a position facing the print head, and the end writing head unit is supported by the apparatus main body frame so as to be movable toward and away from the first medium transport roller. Further, the urging member such as a tension coil spring urges the end printing head unit in a direction approaching the first medium conveyance roller, and the second medium conveyance roller is pressed against the first medium conveyance roller. Is done.

  In the printer of this configuration, the endorsement head unit is movable, and the second medium transport roller mounted on the endurance head unit is mounted on the fixed-side front end head unit by an urging member. It is pressed against the first medium transport roller, and the relative positions of both units are defined by the first and second medium transport rollers. Even when both units are displaced due to an external force or the like, the side of the end printing head unit moves corresponding to the displacement, and the urging force of the urging member causes the first medium conveyance roller and the second medium conveyance roller to move. Since the contact state is maintained and the relative positions of both units are maintained constant, the disturbance resistance of the platen gap of both the front and back print heads is improved.

  The relative positions of the front writing head unit and the end writing head unit are defined by the contact of the first medium transport roller and the second medium transport roller. The interval between these rollers changes following the thickness of the recording medium being conveyed. As a result, the relative positions of the front writing head unit and the back writing head unit defined by the contact of these rollers change. As a result, the distance between the front writing print unit on the front writing head unit side and the front writing platen on the end writing head unit side changes according to the thickness of the transported recording medium, and the end writing head unit side changes. The distance between the print head for endorsement and the platen for endorsement on the side of the head unit for writing is changed. Therefore, the platen gap in both print heads can be made to follow the thickness of the recording medium to be conveyed.

  Next, in the above embodiment, a platen lever unit having an L-shaped arm portion is used, but a platen lever unit having an arm portion having a shape other than this can also be used. It is also possible to use a platen lever unit that is slidable in the longitudinal direction of the apparatus instead of rotating.

  In the above-described embodiment, the print head for front writing and the back printing is the SIDM print head, but these may be ink jet heads.

  Although the above-described embodiment applies the present invention to a check processing apparatus, the present invention can be similarly applied to a printer that prints on a recording medium other than a check.

  DESCRIPTION OF SYMBOLS 1 Check processing apparatus, 2 Main body case, 3 Medium insertion port, 4 Medium discharge port, 5 Medium conveyance path, 5a Horizontal conveyance path part, 5b Curved conveyance path part, 5c Vertical conveyance path part, 6 Front cover, 7 Operation panel, 8 Opening part, 9 Opening / closing lid, 10 Opening / closing unit, 11 Operation lever, 11a Operation end part, 12 Internal mechanism part, 13 Device body frame, 13a Spring hook, 14 Head unit for writing, 15 Head unit for writing, 15a Spring Hang, 15b Abutting piece, 15c Spring hook, 16 Platen lever unit, 17 Magnetic head, 18 End printing print head, 19 End printing platen, 20 Front writing print head, 21 Front writing platen, 22 First transport roller, 23 Second transport roller, 24 First media transport roller, 25 Second media transport roller, 2 Ink ribbon cassette, 27 Ink ribbon cassette mounting part, 28 Ink ribbon cassette, 29 Ink ribbon cassette mounting part, 31 Platen lever, 32 Platen lever, 31a Horizontal arm part, 31b Vertical arm part, 31c Spring hook, 31d Rear end face, 33 Connecting plate, 34 Rotation center axis, 35 lever tension coil spring, 36 unit tension coil spring, CL1 rotation center line, A rotation fulcrum, B current contact, C nip

Claims (5)

Body frame,
A first head unit on which a first print head, a first medium transport roller, and a second platen are mounted and rotatably supported by the main body frame ;
First platen down, the second media transportation roller, and is mounted a second print head, a second head unit supported by the body frame so as to be movable in approaching and leaving directions with respect to the first media transportation roller ,
Provided between the second head unit and the main body frame, the second head unit is urged in a direction approaching the first medium transport roller to turn the second medium transport roller to the first medium transport roller. It includes a biasing member pressed is, a,
In the second head unit, the first print head and the first platen are opposed to each other, the second print head and the second platen are opposed to each other, and the second medium conveyance roller is in contact with the first medium conveyance roller. It is placed at the contact point,
When the distance between the first medium transport roller and the second medium transport roller changes due to the thickness of the medium transported by the first medium transport roller and the second medium transport roller, the first head unit is moved with respect to the first head unit. A printer characterized in that the relative position of the second head unit changes . Body frame,
A first head unit on which a first print head, a first medium transport roller, and a second platen are mounted and rotatably supported by the main body frame ;
It is mounted a second media transportation roller and a first platen, a movable member attached to said body frame so as to be movable in approaching and leaving directions with respect to the first media transportation roller,
It is mounted a second print head, a second head unit supported by the movable main body frame toward and away direction with respect to the first media transportation roller,
Provided between the moving member and the second head unit, urging the moving member in a direction approaching the first medium transport roller and pressing the second medium transport roller against the first medium transport roller A first biasing member,
A second biasing member provided between the second head unit and the main body frame and biasing the second head unit in a direction approaching the first medium transport roller and pressing the second head unit against the moving member; , has a,
In the first head unit, the moving member, and the second head unit, the first print head and the first platen face each other, the second print head and the second platen face each other, and the first medium It is disposed at a position where the second medium transport roller comes into contact with the transport roller,
When the distance between the first medium transport roller and the second medium transport roller changes due to the thickness of the medium transported by the first medium transport roller and the second medium transport roller, the first head unit is moved with respect to the first head unit. A printer characterized in that the relative position of a moving member changes . In claim 2,
The moving member is a turning member that can turn around a predetermined turning fulcrum,
The printer according to claim 1, wherein the first biasing member is a tension coil spring that spans between the rotating member and the second head unit. In any one of claims 1 to 3,
When viewed along the conveyance direction of the recording medium passing through the nip portion of the first medium conveyance roller and the second medium conveyance roller, the nip portion is sandwiched, and the first print head and the second print head One of the printers is located on the upstream side in the transport direction, and the other is located on the downstream side in the transport direction. In any one of claims 1 to 4,
The first print head and the second print head are dot impact heads;
Each of the first head unit and the second head unit includes an ink ribbon cassette mounting portion.

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