JP6237073B2 - Medium conveying apparatus and recording apparatus - Google Patents

Description

The present invention relates to a medium transport apparatus and a recording apparatus including the medium transport apparatus.
In the present application, the recording apparatus includes types such as an ink jet printer, a line printer, a copying machine, and a facsimile.

  Some recording apparatuses typified by facsimiles and printers are capable of recording on both sides of a recording sheet as an example of a medium. Such a recording apparatus has a reversing path for reversing the recording paper as disclosed in, for example, Patent Document 1, and the recording paper recorded on the first surface (front surface) is back-fed. The sheet enters the reversal path, and is conveyed again to the area facing the recording head with the second surface (back surface) facing up.

JP 2012-240813 A

  In the recording apparatus described in Patent Document 1, a reversing path is formed using the outer peripheral surface of one roller (hereinafter referred to as “reversing roller”). Accordingly, in order to reverse a sheet having a large sheet size such as A3 size, it is necessary to increase the reversing roller.

  However, if the reversing roller is enlarged in order to reverse the paper having a large paper size, for example, when the paper having a small paper size such as A4 size is reversed by the reversing roller, the paper having the small paper size is The reversing path set according to the large size paper is conveyed.

  Therefore, a sheet having a small sheet size moves an extra distance when the sheet is reversed in the reversing path. As a result, in the reversing path provided with the reversing roller, the time for reversing a sheet having a small sheet size becomes longer, and the throughput is lowered.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a medium transport apparatus and a recording apparatus including a reversing path capable of reversing media having different sizes and improving throughput. And

  In order to achieve the above object, a medium transport apparatus according to a first aspect of the present invention includes a first roller that reverses a medium fed from a processing unit that processes a medium, and the processing unit with respect to the first roller. And the function of reversing the medium sent from the processing unit side, and the outer peripheral surface faces both the medium conveyance path before reversal by the first roller and the medium conveyance path after reversal. A second roller having a function of imparting a conveyance force to the medium, and a first medium conveyance that reverses the medium sent from the processing unit side along the first roller and sends the medium to the processing unit side. And a second medium conveyance path that reverses the medium sent from the processing unit side along the second roller and sends the medium to the processing unit side.

  According to this aspect, the medium sent from the processing unit side is reversed along the first roller and sent to the processing unit side, and the medium is sent from the processing unit side. A second medium transport path that reverses the medium along the second roller positioned on the processing unit side with respect to the first roller and sends the medium to the processing unit side. A path for inverting the medium can be selected according to the length in the transport direction.

  As a result, with a medium having a short length in the transport direction, the second medium transport path can be used to reverse the moving distance shorter than when the first medium transport path is used, and the transport time is also short. can do. Therefore, the medium conveyance device of this aspect can reverse the papers having different paper sizes and can improve the throughput.

  The medium transport apparatus according to the second aspect of the present invention is located on the side of the processing unit with respect to the first roller that reverses the medium fed from the side of the processing unit that processes the medium, and the first roller, A function of reversing the medium sent from the processing unit side and an outer peripheral surface facing both the medium conveyance path before the reversal by the first roller and the medium conveyance path after the reversal give a conveyance force to the medium. A second roller having a function, a first medium conveyance path for reversing the medium sent from the processing unit side along the first roller and sending the medium to the processing unit side, and the processing unit And a second medium conveyance path for sending the medium fed from the side to the processing unit side by shortcutting between the first roller and the second roller.

  According to this aspect, the medium sent from the processing unit side is reversed along the first roller and sent to the processing unit side, and the first medium transport path is sent from the processing unit side. And a second medium transport path for sending the medium to the processing unit with a shortcut between the first roller and the second roller, so that the medium is transported according to the length of the medium in the transport direction. The path to be reversed can be selected.

  As a result, in a medium having a short length in the transport direction, by using the second medium transport path that shortcuts between the first roller and the second roller, the first medium transport path is used. Can be reversed with a short movement distance and the conveyance time can be shortened. Therefore, the medium conveyance device of this aspect can reverse the papers having different paper sizes and can improve the throughput.

  According to a third aspect of the present invention, in the first or second aspect, the medium transport apparatus includes a transport roller pair positioned between the processing unit and the second roller, and has a length in the transport direction of the medium. Is longer than the length from the pair of transport rollers to the pair of transport rollers via the second medium transport path, the medium sent from the processing unit side is transported by the first medium transport path. When the length of the medium in the transport direction is equal to or shorter than the length from the pair of transport rollers to the pair of transport rollers via the second medium transport path, the medium sent from the processing unit side is It is transported by the second medium transport path.

  According to this aspect, when the length of the medium in the conveyance direction is longer than the length from the conveyance roller pair to the conveyance roller pair via the second medium conveyance path, the medium is fed from the processing unit side. The medium to be conveyed is conveyed by the first medium conveyance path, and the length of the medium in the conveyance direction is not more than the length from the conveyance roller pair to the conveyance roller pair via the second medium conveyance path. In this case, since the medium sent from the processing unit side is transported by the second medium transport path, the medium transport path is properly used according to the length of each medium, and the second pair of transport rollers is used to It is possible to shorten the transport distance in a medium having a length equal to or shorter than the length reaching the pair of transport rollers via the medium transport path.

  As a result, an extra distance is not conveyed from the conveyance roller pair to the conveyance roller pair through the second medium conveyance path, and the second distance from the conveyance roller pair is not increased. It is possible to shorten the transport time of a medium having a length equal to or shorter than the length of the transport roller pair through the medium transport path. Therefore, the medium conveyance device of this aspect can reverse the papers having different paper sizes and can improve the throughput.

  The recording apparatus according to a fourth aspect of the present invention is the recording apparatus according to any one of the first to third aspects, wherein the recording apparatus is located between the first roller and the second roller and is sent from the processing unit side. Switching means capable of switching between a first attitude for conveying the medium to the first medium conveyance path and a second attitude for conveying the medium sent from the processing unit side to the second medium conveyance path. It is characterized by that.

  According to this aspect, the first posture which is located between the first roller and the second roller and transports the medium sent from the processing unit side to the first medium transport path, and the processing Switching means capable of switching between the second posture for transporting the medium sent from the section side to the second medium transport path, so that the medium transport used by the medium transported according to the length of each medium The route can be switched. As a result, since an extra distance is not transported in each medium, the transport time in each medium can be shortened. Therefore, the medium conveyance device of this aspect can reverse the papers having different paper sizes and can improve the throughput.

A recording apparatus according to a fifth aspect of the present invention includes a processing unit that processes a medium, and the medium conveying apparatus according to any one of the first to fourth aspects.
According to this aspect, the same effect as any one of the first to fourth aspects can be obtained.

  A recording apparatus according to a sixth aspect of the present invention includes a processing unit that processes a medium, a medium conveyance device according to the fourth aspect, a control unit that controls the medium conveyance device, and a detector that detects the medium. The control unit switches between the first attitude and the second attitude of the switching unit based on the length of the medium in the conveyance direction of the medium detected by the detector. .

  According to this aspect, in addition to the function and effect of the fourth aspect, the control unit switches the posture of the switching unit based on the information on the length of the medium detected by the detector. Can be selected. As a result, in this recording apparatus, sheets having different sheet sizes can be reversed and throughput can be improved.

FIG. 3 is a rear perspective view of the printer according to the invention. FIG. 3 is a side cross-sectional view illustrating a medium conveyance path from a medium accommodating portion of the printer according to the first embodiment of the present invention. The enlarged view of the conveyance part periphery which concerns on a 1st Example. FIG. 3 is a control block diagram of the printer according to the invention. FIG. 3 is a side sectional view showing a first medium conveyance path of the printer in the first embodiment according to the invention. FIG. 4 is a side sectional view showing a second medium conveyance path of the printer in the first embodiment according to the invention. FIG. 3 is a side cross-sectional view illustrating a medium conveyance path of a medium conveyed from the front feeding path in the printer according to the first embodiment of the present invention. The enlarged view of the conveyance part periphery which concerns on the example of a change of a 1st Example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, about the same structure in each Example, the same code | symbol is attached | subjected and it demonstrates only in the first Example, The description of the structure is abbreviate | omitted in a subsequent Example.

  FIG. 1 is a rear perspective view of a printer according to the present invention, FIG. 2 is a side sectional view showing a medium conveyance path from a medium accommodating portion of the printer according to the first embodiment of the present invention, and FIG. FIG. 4 is an enlarged view of the periphery of a transport unit according to the first embodiment, FIG. 4 is a control block diagram of the printer according to the present invention, and FIG. 5 is a first medium of the printer according to the first embodiment of the present invention. It is a sectional side view which shows a conveyance path | route.

  FIG. 6 is a side sectional view showing a second medium conveyance path of the printer in the first embodiment according to the present invention, and FIG. 7 shows conveyance from the front feed path in the printer in the first embodiment according to the present invention. FIG. 8 is a side sectional view showing a medium transport path of a medium to be used, and FIG. 8 is an enlarged view of the periphery of the transport unit according to a modified example of the first embodiment.

  In the XYZ coordinate system shown in each figure, the X direction is the scanning direction of the recording head, the Y direction is the depth direction of the recording apparatus, and the Z direction is the distance (gap) between the recording head and the medium. The direction, that is, the device height direction is shown. In each figure, the -Y direction is the front side of the apparatus, and the + Y direction side is the back side of the apparatus.

■■■ Printer overview ■■■■■■■
Referring to FIG. 1, a printer 10 according to the present invention is shown. The printer 10 includes an apparatus main body 12 and a document reading device 14 provided on an upper portion of the apparatus main body 12 so as to be rotatable with respect to the apparatus main body 12. The apparatus main body 12 includes a back cover 16 configured to be rotatable with respect to the apparatus main body 12 on the apparatus rear side (FIG. 1 + Y direction side). In FIG. 1, the back cover 16 is closed with respect to the apparatus main body 12.

  Next, the conveyance path 18 of the paper P as a “medium” in the printer 10 will be described with reference to FIG. The printer 10 includes, in the apparatus main body 12, a medium storage unit 20, a conveyance unit 22 as a “medium conveyance device”, a recording unit 24 as a “processing unit”, a discharge unit 26, and a control unit 28 (see FIG. 4). And. 2 is a conveyance path 18 of the paper P from the medium storage unit 20 to the discharge unit 26 via the conveyance unit 22 and the recording unit 24.

  The medium storage unit 20 includes a paper feed cassette 30 located on the printer 10 at the lower side in the Z-axis direction in FIG. The sheet feeding cassette 30 is configured to be attachable to and detachable from the apparatus main body 12 from the apparatus front side (the −Y direction side in FIG. 2).

  Above the paper feed cassette 30, feed rollers 32 and 32 that are driven to rotate by a drive source (not shown) are provided. Further, the bottom plate 30a of the paper feed cassette 30 is configured as a hopper that supports the paper P and biases the paper P against the feed roller 32 positioned in the + Z-axis direction in FIG.

  When the paper P accommodated in the paper feed cassette 30 is fed to the downstream side of the conveyance path by the control of the control unit 28 (see FIG. 4), the feeding roller 32 moves the top of the paper P accommodated in the paper feed cassette 30. By rotating in contact with the upper one, the uppermost sheet P is sent out from the sheet feeding cassette 30 to the downstream side of the conveyance path.

  Further, when the back cover 16 is closed with respect to the apparatus main body 12, the inner surface thereof constitutes a part of the transport path of the paper P. That is, the feeding path section 34 formed inside the back cover 16 guides the paper P sent out from the paper feed cassette 30 to the transport section 22 along the transport path 18.

  The transport unit 22 includes a first roller 36, a second roller 38, a first transport driven roller 40, a second transport driven roller 42, a third transport driven roller 44, a fourth transport driven roller 46, a fifth transport driven roller 48, and A pair of transport rollers 50 is provided. The first roller 36 and the second roller 38 are configured as a unit body 52 that can be attached to and detached from the apparatus main body 12. In the unit body 52, a shortcut transport path 54 as a “second medium transport path” is provided between the first roller 36 and the second roller 38. The shortcut transport path 54 will be described later.

  The unit body 52 rotates when the back cover 16 is rotated in the + Y-axis direction in FIG. 2 with respect to the apparatus main body 12 so that the back cover 16 is opened with respect to the apparatus main body 12. It can be attached to and detached from the apparatus main body 12 from the axial direction side. In the present embodiment, the first roller 36 and the second roller 38 have a common drive (not shown) when the unit body 52 is attached to the apparatus main body 12 and the back cover 16 is closed with respect to the apparatus main body 12. Each of the sources is rotated in the clockwise direction in FIG.

  The paper P is fed along the conveyance path 18 in the conveyance unit 22 by a fifth conveyance driven roller 48 and a third conveyance driven roller 44 that abut on the first roller 36 and a second conveyance driven roller 42 and a second conveyance driven roller 42 that abut on the second roller 38. 1 transported to a transport roller pair 50 via a transport driven roller 40. A recording unit 24 is provided on the downstream side of the conveyance path of the conveyance roller pair 50 of the conveyance unit 22.

  The recording unit 24 faces the recording head 58, a carriage 56 that is movable in the scanning direction (X-axis direction in FIG. 2), a recording head 58 that is provided below the carriage 56, and that ejects ink onto the paper P. And a platen 60 provided to support the paper P.

  Further, a discharge unit 26 is provided on the downstream side of the conveyance path of the recording unit 24. The discharge unit 26 is provided with a pair of discharge rollers 62. The sheet P sent from the transport unit 22 to the recording unit 24 along the transport path 18 is recorded on the first surface (front surface). After recording, the paper P is nipped by the discharge roller 62 and discharged from an opening 64 provided on the front side of the apparatus main body 12 toward a discharge stacker 66 provided on the front side of the apparatus. The discharge stacker 66 supports the discharged paper P.

  In addition to the conveyance path 18 from the medium storage unit 20 to the recording unit 24 via the conveyance unit 22, the printer 10 is configured to print paper from the front side of the printer 10 (the −Y axis direction side in FIGS. 2 and 7). A front feeding path 68 (see a two-dot chain line in FIG. 7) as a “merging path” for supplying P is provided.

  The front feeding path 68 includes a front medium support unit 70 and a conveyance path 72 located on the −Z axis direction side in FIG. 2 of the recording unit 24. The front medium support unit 70 functions as a paper feed tray when transporting the paper P from the front side of the printer 10 (the −Y axis direction side in FIG. 2) to the transport unit 22. At least a part of the front medium support unit 70 supports the paper P together with the discharge stacker 66 when the paper P is discharged to the discharge stacker 66.

  The conveyance path 72 is configured to convey the paper P supported by the front medium support unit 70 toward the nip point between the second roller 38 and the fourth conveyance driven roller 46. The front feed path 68 will be described later.

  A medium detector 74 as a “detector” is provided on the upstream side of the conveyance path of the conveyance roller pair 50 of the conveyance unit 22. As an example, the medium detector 74 starts detection of the paper P when it passes the medium detector 74 when the leading edge of the paper P is transported toward the recording unit 24 along the transport path 18, and is detected by the control unit 28. Send a signal. When the trailing edge of the paper P crosses the medium detector 74 toward the recording unit 24, the detection of the paper P is finished, and transmission of the detection signal to the control unit 28 is stopped.

  In the present embodiment, as an example, the control unit 28 rotationally drives the first roller 36 and the second roller 38 in the transport unit 22 from when the detection signal from the medium detector 74 is received until it stops. The rotation speed of a common drive source (not shown) is monitored using an encoder (not shown) and the like, and the length of the paper P in the transport direction is calculated based on the detected rotation speed.

■■■ First Example ■■■■■■■
■■■ About the reverse path of the medium sent from the recording unit ■■■■■■■
Next, two reversing paths for reversing the paper P will be described with reference to FIGS. 3, 5, and 6. As shown in FIG. 3, in the unit body 52, the upper surface 52a and the lower surface of the unit body 52 are arranged between the first roller 36 and the second roller 38 in the height direction of the unit body 52, that is, in the Z-axis direction in FIG. A shortcut transport path 54 is provided to connect 52b.

  In the present embodiment, the shortcut conveyance path 54 is formed to be curved along the second roller 38. Further, a flap 76 as a “switching means” is provided on the lower surface 52 b of the unit body 52 on the entrance side of the shortcut conveyance path 54. That is, the flap 76 is located between the first roller 36 and the second roller 38.

  The flap 76 is configured to be switchable between a posture in which the entrance of the shortcut transport path 54 is closed (see the broken line state in FIG. 3) and a posture in which the entrance is open (see the solid line state in FIG. 3). Specifically, the posture of the flap 76 is switched by a driving source (such as a solenoid) (not shown) controlled by the control unit 28. Here, in the flap 76, a posture in which the entrance of the shortcut transport path 54 is closed is referred to as a first posture, and a posture in which the entrance of the shortcut transport route 54 is open is referred to as a second posture.

  Here, the switching operation of the flap 76 between the first posture and the second posture will be described. A broken line route denoted by reference numeral 78 in FIG. 3 indicates a second medium conveyance route 78 described later. Here, the path length L of the second medium transport path 78 is the length of the path from the transport roller pair 50 to the transport roller pair 50 again via the shortcut transport path 54. In this embodiment, as an example, the path length L of the second medium transport path 78 is set to the length of the A4 size paper.

  When the length in the transport direction of the sheet P obtained based on the detection information of the medium detector 74 and the encoder (not shown) is longer than the path length L of the second medium transport path 78, the control unit 28 The flap 76 is in the first posture (see the broken line state in FIG. 3). Further, when the length of the paper P in the transport direction is equal to or shorter than the path length L of the second medium transport path 78, the control unit 28 sets the flap 76 to the second posture (see the solid line state in FIG. 3).

  Next, referring to FIG. 5, the alternate long and short dash line denoted by reference numeral 80 is the first medium transport path 80. When the paper P is fed back from the recording unit 24 to the transport unit 22 in order to reverse the first surface (front surface) and the second surface (back surface) of the paper P, the control unit 28 sets the length in the transport direction of the paper P. Is longer than the path length L of the second medium transport path 78, the flap 76 is in the first posture (see the broken line state in FIG. 3), and the paper P is transported along the first medium transport path 80. To do.

  Specifically, when the paper P is transported from the recording unit 24 to the transport unit 22, the paper P is positioned below the lower surface 52b of the unit body 52 from the −Y axis direction side to the + Y axis direction side in FIG. The sheet P is reversed using the outer peripheral surface of the first roller 36 through the medium conveyance path before reversing.

  Then, the paper P reversed by the first roller 36 is the medium after reversal positioned above the upper surface 52a of the unit body 52 from the + Y-axis direction side to the −Y-axis direction side in FIG. It passes through the transport path and is sent to the recording unit 24. Specifically, the sheet P is in contact with the first roller 36 along the first medium conveyance path 80, the second conveyance roller 48, the third conveyance driven roller 44, and the second conveyance 38 abutting on the second roller 38. It is conveyed to the conveyance roller pair 50 via the driven roller 42 and the first conveyance driven roller 40.

  Then, the paper P is sent again to the recording unit 24 located on the downstream side in the conveyance direction of the conveyance roller pair 50, and recording is performed on the second surface (back surface) in the recording unit 24. That is, the first medium conveyance path 80 is a recording medium after the medium P is reversed along the first roller 36 and the medium conveyance path before reversing the sheet P sent from the recording unit 24 to the first roller 36. And a medium conveyance path after reversal that is sent toward the unit 24. In this embodiment, for example, the A3 size paper P is reversed along the first medium conveyance path 80.

  Next, referring to FIG. 6, a two-dot chain line denoted by reference numeral 78 is a second medium conveyance path 78. When the paper P is fed back from the recording unit 24 to the transport unit 22 in order to reverse the first surface (front surface) and the second surface (back surface) of the paper P, the control unit 28 sets the length in the transport direction of the paper P. Is determined to be less than or equal to the path length L of the second medium transport path 78, the flap 76 is in the second posture (see the solid line state in FIG. 3), and the paper P is moved along the second medium transport path 78. Transport.

  Specifically, when the paper P is transported from the recording unit 24 to the transport unit 22, the paper P is positioned below the lower surface 52b of the unit body 52 from the −Y axis direction side to the + Y axis direction side in FIG. The medium is transported on the medium transport path before reversing, and is guided into the shortcut transport path 54 by the flap 76 in the second posture. The paper P is reversed by passing through the shortcut conveyance path 54.

  Then, the paper P reversed by passing through the shortcut transport path 54 is inverted above the upper surface 52a of the unit body 52 from the + Y-axis direction side to the −Y-axis direction side in FIG. It passes through the subsequent medium conveyance path and is sent to the recording unit 24. Specifically, the paper P is transported to the transport roller pair 50 through the second transport driven roller 42 and the first transport driven roller 40 that are in contact with the second roller 38 along the second medium transport path 78. .

  Then, the paper P is sent again to the recording unit 24 located on the downstream side in the conveyance direction of the conveyance roller pair 50, and recording is performed on the second surface (back surface) in the recording unit 24. That is, the second medium transport path 78 passes the paper P through the shortcut transport path 54 and the medium transport path before reversal for guiding the paper P sent from the recording unit 24 to the shortcut transport path 54. Inverted and transported to the recording unit 24, the medium transport path after inversion is provided. In this embodiment, for example, a sheet P of A4 size or smaller is reversed along the second medium conveyance path 78.

  Therefore, the printer 10 and the conveyance unit 22 reverse the paper P sent from the recording unit 24 side along the first roller 36 and send it to the recording unit 24 side, and the recording unit 24. A second medium conveyance path 78 that reverses the sheet P fed from the first side along the second roller 38 positioned on the recording unit 24 side with respect to the first roller 36 and sends it to the recording unit 24 side. ing.

  Therefore, in the printer 10 and the transport unit 22, a path for inverting the paper P can be selected according to the length of the paper P in the transport direction. As a result, when the length of the paper P in the transport direction is equal to or shorter than the path length L of the second medium transport path 78, for example, the paper size is A4 or less, the second medium transport path 78 is used for transporting the paper P. By using, it is possible to reverse the moving distance shorter than when using the first medium transport path 80 and to shorten the transport time. Therefore, the printer 10 and the conveyance unit 22 can reverse the papers having different paper sizes and improve the throughput.

  Further, the first medium transport path 80 and the second medium transport path 78 are selectively used according to the length of the paper P in the transport direction, and the transport distance of the paper P having a length equal to or shorter than the path length L is shortened. I'm going. As a result, an extra distance is not conveyed on the paper P having a length equal to or shorter than the path length L, so that the conveyance time on the paper P having a length equal to or shorter than the path length L can be shortened. Therefore, the printer 10 and the conveyance unit 22 can reverse the papers having different paper sizes and improve the throughput.

  Further, the control unit 28 changes the posture of the flap 76 from the recording unit 24 side according to the length in the conveyance direction of the paper P obtained based on the detection information of the medium detector 74 and the encoder (not shown). Since the first posture in which the fed paper P is transported to the first medium transport path 80 and the second posture in which the paper P fed from the recording unit 24 side is transported to the second medium transport path 78 are switched. The first medium transport path 80 and the second medium transport path 78 can be switched according to the length of P in the transport direction.

  As a result, an extra distance is not conveyed on the paper P having a length equal to or shorter than the path length L, so that the conveyance time on the paper P having a length equal to or shorter than the path length L can be shortened. Therefore, the printer 10 and the conveyance unit 22 can reverse the papers having different paper sizes and improve the throughput.

  In the present embodiment, the first medium transport path 80 and the second medium transport path 78 are selectively used as the path for reversing the paper P in accordance with the length in the transport direction of the paper P. Can be reduced. Specifically, since the first roller 36 pulls up the paper P from the medium storage unit 20, the load is larger than that of the second roller 38 and is easily worn.

  That is, when the sheet P having a short length in the transport direction is reversed, using the second medium transport path 78 reduces the load on the first medium transport path 80 and thus the first roller 36. As a result, the lifetime of the first roller 36 is extended, so that the lifetime of the printer 10 and the transport unit 22 can be increased.

■■■ About the front feed path ■■■■■■■
Next, referring to FIG. 7, a front feeding path 68 (two-dot chain line in FIG. 7) that conveys the paper P supplied from the front side of the printer 10 (the −Y axis direction side in FIG. 7) to the recording unit 24. Will be described.

  In the front feed path 68, the paper P supported by at least a part of the front medium support unit 70 and the discharge stacker 66 is transported along the transport path 72 by a feed roller 82 driven by a drive source (not shown). It is conveyed toward. The conveyance path 72 joins a reversing path that is conveyed from the recording unit 24 toward the conveyance unit 22. Specifically, the conveyance path 72 is on the second medium conveyance path 78 on the upstream side in the conveyance direction from the nip point between the second roller 38 and the fourth conveyance driven roller 46 in the conveyance unit 22, that is, on the recording unit 24 side. Merges with the medium conveyance path before reversal.

  Here, when the paper P is supplied from the front feeding path 68, the paper P reaches the transport roller pair 50 through the front feed path 68 and the second medium transport path 78, and is therefore nipped by the transport roller pair 50. The leading edge of the sheet P does not overlap the trailing edge of the sheet P regardless of the length in the conveyance direction of the sheet P.

  Therefore, when the paper P is supplied from the front feeding path 68, the control unit 28 switches the flap 76 to the second posture and guides the paper P from the front feeding path 68 to the second medium conveyance path 78. It is conveyed to the recording unit 24. The sheet P conveyed to the recording unit 24 is recorded on the first surface (front surface) of the sheet P in the recording unit 24. When double-sided recording is not performed, the paper P is conveyed toward the discharge unit 26.

  Next, the reverse path when performing double-sided recording on the paper P supplied from the front feeding path 68 to the recording unit 24 via the second medium conveyance path 78 will be described. When the paper P is supplied from the front feeding path 68 to the recording unit 24 via the second medium conveyance path 78, the control unit 28 detects the paper P by the medium detector 74. When recording on the second surface (back surface) of the paper P, the control unit 28 calculates the length of the paper P in the transport direction based on detection information of the medium detector 74 and an encoder (not shown).

  When the length of the paper P in the transport direction is longer than the path length L of the second medium transport path 78, the control unit 28 sets the flap 76 to the first posture (see the broken line state in FIG. 3) and sets the paper P to the first position. It is conveyed along the medium conveyance path 80. When the length of the paper P in the transport direction is equal to or shorter than the path length L of the second medium transport path 78, the control unit 28 sets the flap 76 to the second posture (see the solid line state in FIG. 3) and It is conveyed along the second medium conveyance path 78.

  Regardless of the length in the transport direction, the paper P supplied from the front feeding path 68 passes through the shortcut transport path 54 that shortcuts between the first roller 36 and the second roller 38, and the second medium transport path. Since it is transported along the line 78 to the recording unit 24, the transport distance is shorter than when traveling to the recording unit 24 through the first medium transport path 80, and the transport time can be shortened. As a result, the recording time of the paper P supplied from the front feeding path 68 can be shortened, and the throughput when the paper P is supplied from the front feeding path 68 can be improved.

  Further, the front feeding path 68 joins at the position on the recording unit 24 side with respect to the second roller in the medium conveyance path before the reversal in the second medium conveyance path 78, and is thus conveyed from the front feeding path 68. The received paper P can be transported to the recording unit 24 via the second medium transport path 78. As a result, the length of the path from the front feeding path 68 to the recording unit 24 is shorter than that when passing through the first medium transport path 80, so the transport time is shortened, and the sheet P is fed from the front feeding path 68. Throughput at the time of supply can be improved.

  In addition, since the control unit 28 switches the posture of the flap 76 based on the information on the length of the paper P detected by the medium detector 74, a medium conveyance path corresponding to the length of the paper P can be selected. As a result, in the printer 10 and the conveyance unit 22, it is possible to invert sheets with different sheet sizes and improve throughput.

<<< Modification of the first embodiment >>>
(1) In the present embodiment, the shortcut transport path 54 is configured as a path for reversing the paper P along the second roller 38, but the shortcut transport path 54 is formed at the first roller 36, the second roller 38, and the like. It suffices if it is located between.
(2) In the present embodiment, the flap 76 is provided on the lower surface 52b of the unit body 52 in the transport unit 22, but instead of this structure, the flap 84 is provided on the unit body 12 side as shown in FIG. 52 may be provided at a position opposite to the entrance of the shortcut transport path 54 on the lower surface 52b of 52.
(3) In this embodiment, when the length of the paper P in the transport direction is equal to or shorter than the path length L of the second medium transport path 78, the paper P is transported along the second medium transport path 78. However, instead of this configuration, even when the length of the paper P is equal to or shorter than the path length L, the control section 28 causes the paper P to be the first when the printing duty, ink drying time, high-density recording is performed, and the like. It may be controlled so as to be conveyed along the medium conveyance path 80.

  To summarize the above description, the transport unit 22 of the present embodiment includes a first roller 36 that reverses the paper P sent from the recording unit 24 that processes the paper P, and the recording unit 24 with respect to the first roller 36. And the function of reversing the sheet P fed from the recording unit 24 side, and the outer peripheral surface of the first roller 36 face both the medium conveyance path before reversal and the medium conveyance path after reversal. A first roller having a function of imparting a conveying force to the medium, and a first medium that reverses the sheet P fed from the recording unit 24 side along the first roller 36 and sends the sheet P to the recording unit 24 side. A conveyance path 80 and a second medium conveyance path 78 for reversing the sheet P sent from the recording unit 24 side along the second roller 38 and sending it to the recording unit 24 side are provided.

  The transport unit 22 is positioned on the recording unit 24 side with respect to the first roller 36 for reversing the paper P sent from the recording unit 24 side for processing the paper P, and is disposed on the recording unit 24 side. A function of reversing the sheet P fed from the side, a function of imparting a transport force to the medium with its outer peripheral surface facing both the medium transport path before reversal by the first roller 36 and the medium transport path after reversal, , A first medium conveyance path 80 that reverses the sheet P sent from the recording unit 24 side along the first roller 36 and sends it to the recording unit 24 side, and the recording unit 24 side. A second medium transport path 78 for sending the sheet P fed from the first roller 36 and the second roller 38 to the recording unit 24 side by a shortcut.

  The transport unit 22 includes a transport roller pair 50 positioned between the recording unit 24 and the second roller 38, and the length of the paper P in the transport direction is from the transport roller pair 50 via the second medium transport path 78. When the paper length P is longer than the path length L reaching the transport roller pair 50, the paper P sent from the recording unit 24 side is transported by the first medium transport path 80, and the length of the paper P in the transport direction is equal to the transport roller pair. When the length is less than or equal to the path length L from 50 to the conveyance roller pair 50 via the second medium conveyance path 78, the paper P sent from the recording unit 24 side is conveyed by the second medium conveyance path 78.

  The transport unit 22 is located between the first roller 36 and the second roller 38, and has a first posture for transporting the paper P sent from the recording unit 24 side to the first medium transport path 80, and the recording unit 24. Flaps 76 and 84 that can switch between a second posture in which the paper P fed from the side of the paper P is conveyed to the second medium conveyance path 78 are provided.

  The printer 10 includes a recording unit 24 that processes the paper P and a transport unit 22. Alternatively, the printer 10 includes the recording unit 24 that processes the paper P and the conveyance unit 22 provided with flaps 76 and 84. A control unit 28 that controls the conveyance unit 22 and a medium detector 74 that detects the paper P are provided. The control unit 28 switches between the first posture and the second posture of the flaps 76 and 84 based on the length in the transport direction of the paper P detected by the medium detector 74.

In this embodiment, the transport unit 22 according to the present invention is applied to an ink jet printer as an example of a recording apparatus. However, the present invention can also be applied to other liquid ejecting apparatuses in general.
Here, the liquid ejecting apparatus uses an ink jet recording head, and is not limited to a recording apparatus such as a printer, a copier, and a facsimile machine that discharges ink from the recording head to perform recording on a recording medium. And a device for ejecting a liquid corresponding to the application from a liquid ejecting head corresponding to the ink jet recording head to an ejected medium corresponding to the recording medium, and attaching the liquid to the ejected medium.

  In addition to the recording head, as a liquid ejecting head, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, and an electrode material (conductive paste) used for forming an electrode such as an organic EL display or a surface emitting display (FED) Examples thereof include an ejection head, a bioorganic matter ejection head used for biochip production, and a sample ejection head as a precision pipette.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.

10 Printer, 12 Device body, 14 Document reader, 16 Back cover,
18 transport path, 20 medium storage unit, 22 transport unit, 24 recording unit, 26 discharge unit,
28 control unit, 30 paper feed cassette, 30a bottom plate, 32, 82 feed roller,
34 feeding path section, 36 first roller, 38 second roller,
40 1st conveyance driven roller, 42 2nd conveyance driven roller,
44 3rd conveyance follower roller, 46 4th conveyance follower roller,
48 5th conveyance driven roller, 52 unit body, 52a upper surface, 52b lower surface,
54 shortcut transport path, 56 carriage, 58 recording head, 60 platen, 62 discharge roller, 64 opening, 66 discharge stacker, 68 front feed path,
70 front medium support, 72 transport path, 74 medium detector, 76, 84 flap,
78 Second medium conveyance path, 80 First medium conveyance path, L path length, P paper

Claims (5)

A first roller for reversing the medium sent from the side of the processing unit for processing the medium;
A function of reversing the medium that is located on the processing unit side with respect to the first roller and fed from the processing unit side, and an outer peripheral surface of the medium transport path before reversing by the first roller and after reversing A second roller having a function of imparting a conveyance force to the medium facing both the medium conveyance path;
A first medium conveyance path for reversing the medium sent from the processing unit side along the first roller and sending the medium to the processing unit side;
A second medium conveyance path that reverses the medium sent from the processing unit side along the second roller and sends the medium to the processing unit side,
A medium conveying apparatus characterized by the above. The medium conveying apparatus according to claim 1 , further comprising a pair of conveying rollers positioned between the processing unit and the second roller,
When the length of the medium in the conveyance direction is longer than the length from the conveyance roller pair to the conveyance roller pair via the second medium conveyance path, the medium sent from the processing unit side is Transported by one medium transport path,
When the length of the medium in the conveyance direction is equal to or shorter than the length from the conveyance roller pair to the conveyance roller pair via the second medium conveyance path, the medium sent from the processing unit side is the first medium. 2 transported by the medium transport path,
A medium conveying apparatus characterized by the above. 3. The medium conveyance device according to claim 1 , wherein the medium that is positioned between the first roller and the second roller and is fed from the processing unit side is transferred to the first medium conveyance path. Switching means capable of switching between a first posture for transporting and a second posture for transporting the medium sent from the processing unit side to the second medium transport path;
A medium conveying apparatus characterized by the above. A processing unit for processing the medium;
The medium conveyance device according to any one of claims 1 to 3 ,
Comprising
A recording apparatus. A processing unit for processing the medium;
A medium conveying device according to claim 3 ;
A control unit for controlling the medium conveying device;
A detector for detecting the medium;
With
The controller switches between the first attitude and the second attitude of the switching unit based on the length of the medium in the conveyance direction of the medium detected by the detector;
A recording apparatus.

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