Printer

Abstract

To correct a meandering of paper in printing by a simple structure with a small number of parts.SOLUTION: A printer 100 according to the present invention includes a paper feed path 81, a reversing roller 77c, a grip roller 77d, and a pair of left and right guide members 51, wherein the guide members 51 are formed of a first portion 51b on the upstream side and a second portion 51a on the downstream side, wherein the first portion 51b is formed at a gradually narrower interval in the feed direction so that the portion closest to the reversing roller 77c is at an interval L2 wider than a width W1 of paper 201, and the portion closest to the second portion 51a is at an interval L1 substantially equal to the width W1, wherein the second portion 51a is formed substantially parallel with the interval L1 substantially equal to the width W1, wherein a second cam 53b for retracting the reversing roller 77c to a position not in contact with the paper 201 while the leading edge of the paper 201 in the feed direction reaches the downstream side portion 51a, and wherein a first cam 53a for moving the movable guide member 52 while the reversing roller 77c is retracted.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a printer.

Background Art

[0002] A printer that prints on a sheet of paper (cut paper) cut to a predetermined length feeds the sheets one by one into a conveyance path by a driving roller. The conveyance path extends from a paper storage section in which the paper is stored, passes through a printing section that prints on the paper, and reaches a discharge port that discharges the paper. Then, the paper is sequentially transferred to a plurality of driving rollers provided on the conveyance path, and is sent along the conveyance path (see, for example, Patent Document 1).

[0003] Here, while the paper is being sent by the driving roller, the posture of the paper may change, or the direction of the feeding direction may change, causing the paper to meander. When the paper meanders, a part of the paper deviates from the area of the conveyance path that the paper should originally pass through, resulting in misalignment of printing on the paper or jamming of the paper inside the printer.

[0004] For this reason, some printers are provided with a meandering correction mechanism that corrects the meandering of the paper by hitting at least one side edge of the paper being sent along the conveyance path from the outside in the width direction of the paper.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the above-described meandering correction mechanism has a problem in that it is composed of a large number of parts, so that the structure is complicated and the cost is high.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide a printer having a simple structure with a small number of components, which can prevent paper jams and correct paper skew while preventing paper jams.

Means for Solving the Problems

[0008] The present invention includes a conveyance path through which single sheets of paper pass, a drive roller provided in an upstream region in the paper feed direction of the conveyance path for feeding the single sheets of paper along the conveyance path, a downstream roller provided on the downstream side in the feed direction of the conveyance path for restraining the single sheets of paper that have passed through the conveyance path, and a pair of guide members disposed outside both side edges of the single sheets of paper passing through the conveyance path for guiding the single sheets of paper by restricting the positions of both side edges of the single sheets of paper. Each of the pair of guide members has a first portion located on the upstream side in the feed direction and a second portion located on the downstream side. The interval between the pair of guide members is such that the portion of the first portion closest to the drive roller is wider than the width of the paper and gradually narrows in the paper feed direction, and the portion closest to the second portion is substantially equal to the width of the single sheet of paper. The interval is gradually narrowed in the paper feed direction. The second portion on the downstream side is formed to have the width of the single sheet of paper. When the region between the drive roller and the second portion is divided into an upstream first region and a downstream second region in the feed direction, the portion of the first portion closest to the drive roller is arranged to be located in the first region. The conveyance path has a space expanding in the thickness direction of the single sheet of paper that can accommodate a bent portion of the single sheet of paper in a mountain-shaped raised state between a leading end side portion of the single sheet of paper whose direction is corrected by the second portion and a trailing end side portion of the single sheet of paper restrained by the drive roller. It is a printer.

Effects of the Invention

[0009] According to the printer according to the present invention, it is possible to prevent paper jams and correct paper skew with a simple structure having a small number of components.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Mode for Carrying Out the Invention

[0011] Embodiments of the printer according to the present invention will be described below with reference to the drawings.

[0012] <Configuration> FIG. 1 is a perspective view showing the appearance of a sublimation thermal printer 100 (hereinafter referred to as printer 100). FIG. 2 is a cross-sectional view taken along a vertical plane passing through the center of the width direction W of printer 100 and along the front-rear direction L. FIG. 3 is a schematic diagram obtained by simplifying and schematically representing FIG. 2 in order to clarify the conveyance path 80 shown in FIG. 2. FIG. 4 is a perspective view showing a state in which the front upper cover 13 of printer 100 is opened and the roll paper storage section 22 is pulled forward in the front-rear direction L. FIG. 5 is a cross-sectional view corresponding to FIG. 2 in the state of FIG. 4.

[0013] The illustrated printer 100 is an embodiment of the printer according to the present invention. Printer 100 includes a case 10, a sheet feeding section 21, a roll paper storage section 22, a printing section 30, a cutter section 40, a conveyance means 70, a conveyance path 80, and a meandering correction mechanism 50.

[0014] (Case) As shown in FIG. 1, case 10 includes a case body 11, an upper cover 12, a front upper cover 13, a front middle cover 14, and a front lower cover 15. Case body 11 is mainly formed so as to cover both side surfaces in the width direction W and the rear surface in the front-rear direction L.

[0015] Upper cover 12 is arranged so as to close the opening on the upper surface in the height direction H of case body 11, and a stacker 12a is formed in which sheets 201 (hereinafter also simply referred to as paper 201) and paper 203 unwound from roll paper 202 are stored.

[0016] Note that the bottom surface 12b of stacker 12a is formed to be inclined so as to become lower from the rear to the front as shown in FIG. 2, and the papers 201 and 203 discharged rearward from the upper discharge port 13b of the front upper cover 13 are accumulated on the front side due to the inclination of the bottom surface 12b.

[0017] The front upper cover 13 is arranged at the upper part of the front surface of the printer 100, the front lower cover 15 is arranged at the lower part of the front surface of the printer 100, and the front middle cover 14 is arranged between the front upper cover 13 and the front lower cover 15 on the front surface of the printer 100.

[0018] The front middle cover 14 is provided with a detachable dustbin 16. The dustbin 16 is arranged below a cutter unit 40 described later and is a part for accommodating pieces of paper cut off from the sheets 201 and 203 by the cutter unit 40. The dustbin 16 is attached so that it can be removed from the front middle cover 14 by sliding upward with respect to the front middle cover 14. Note that FIGS. 4 and 5 show a state where the dustbin 16 is removed.

[0019] As shown in FIGS. 4 and 5, the front upper cover 13 and the front middle cover 14 are provided in an internal drawer unit 60 (an example of a drawer unit). The internal drawer unit 60 is arranged inside the case main body 11 and the upper surface cover 12, and can be pulled forward with respect to the case main body 11 and the upper surface cover 12 by hooking a finger on a finger hook portion 14a formed at the lower part of the front middle cover 14 and pulling it forward in the front-rear direction L.

[0020] The internal drawer unit 60 integrally includes, in addition to the front upper cover 13 and the front middle cover 14, a roll paper storage portion 22, an ink ribbon 32 and a platen roller 33 of a print portion 30, a cutter unit 40, a conveying means 70, a conveying path 80, and a meandering correction mechanism 50.

[0021] The front upper cover 13 is supported so as to be rotatable upward and rearward as indicated by the arrow in FIGS. 4 and 5, from the closed state shown in FIG. 1, to a state where the internal drawer unit 60 is pulled forward from the inside surrounded by the case body 11 and the upper cover 12 as shown in FIGS. 4 and 5. When the front upper cover 13 rotates upward and rearward to an open state, a part of the front and a part of the upper of the roll paper storage portion 22 are opened. Thereby, the roll paper storage portion 22 formed inside the case 10 is exposed, and the roll paper 202 can be taken in and out of the roll paper storage portion 22.

[0022] On the front surface of the front upper cover 13, a front discharge port 13a for discharging the printed papers 201, 203 forward is formed, and on the rear surface of the front upper cover 13, an upper discharge port 13b for discharging the printed papers 201, 203 to the rear stacker formed on the upper cover 12 is formed.

[0023] As shown in FIGS. 2 and 5, the front lower cover 15 is formed as a front portion of the tray-shaped single-sheet paper storage portion 21 (the front lower cover 15 is a part of the single-sheet paper storage portion 21).

[0024] (Single-sheet paper storage portion) As shown in FIG. 2, the single-sheet paper storage portion 21 is provided at the lowermost part of the printer 100 and is disposed below the roll paper storage portion 22. The single-sheet paper storage portion 21 stores the single-sheet papers 201 cut to a predetermined size in a stacked manner in the thickness direction.

[0025] The single-sheet paper storage portion 21 is provided so as to be pullable forward with respect to the case body 11 and the upper cover 12 independently of the internal drawer unit 60 by hooking a finger on the finger hook portion 15a formed on the upper part of the front lower cover 15 and pulling it forward in the front-rear direction L. And the single-sheet paper storage portion 21 is opened upward in a state of being pulled forward with respect to the case body 11 and the upper cover 12, and the single-sheet paper 201 to be stored inside can be taken in and out from the opened upper part.

[0026] (Roll paper storage portion) As described above, the roll paper storage section 22 is formed in the internal drawer unit 60. The roll paper storage section 22 is a portion for storing a roll paper 202 around which a long sheet 203 is wound. As shown in FIGS. 2, 4, and 5, the roll paper storage section 22 stores the roll paper 202 with the axis of the roll paper 202 parallel to the width direction W of the printer 100.

[0027] With the internal drawer unit 60 stored inside the case 10 as shown in FIG. 2, the roll paper storage section 22 is arranged above the single-sheet paper storage section 21. In FIG. 2, the roll paper 202 is arranged in a direction of rotating counterclockwise such that the paper 203 is drawn out and unwound from the lower end of the roll paper 202 in the right direction shown in the figure.

[0028] (Printing section) The printing section 30 is arranged behind the roll paper storage section 22. The printing section 30 performs printing on the sheets 201 and 203 passing through a portion (printing path 82, to be described later) that rises substantially vertically behind the roll paper storage section 22 in the conveyance path 80 under the control of the control section 95 of the printer 100.

[0029] The printing section 30 includes a thermal head 31, an ink ribbon 32, and a platen roller 33. The ink ribbon 32 feeds the ribbon from the feeding-side roll 32a to the winding-side roll 32b in synchronization with the conveyance of the sheets 201 and 203, and by diffusing and transferring the sublimation dye applied to the ribbon onto the sheets 201 and 203 due to the heat generation of the thermal head 31 in contact with the ribbon, printing is performed on the sheets 201 and 203.

[0030] The ink ribbon 32 is provided in the internal drawer unit 60. As shown in FIGS. 4 and 5, the internal drawer unit 60 can be pulled forward from the case body 11, passed in an arc shape above the roll paper storage section 22, and pulled forward, facilitating the replacement of the ink ribbon 32.

[0031] The platen roller 33 is disposed on the opposite side of the ink ribbon 32 and the thermal head 31 with the sheets of paper 201, 203 therebetween. The platen roller 33 presses the sheets of paper 201, 203 against the thermal head 31 with the ribbon therebetween.

[0032] (Cutter section) The cutter section 40 is disposed inside the front upper cover 13 in front of the roll paper storage section 22. The cutter section 40 cuts the sheets of paper 201, 203 passing through a portion (discharge path 83, described later) of the conveyance path 80 that extends forward from above the roll paper storage section 22 along the width direction W under the control of the control section 95 of the printer 100. The cut pieces of the sheet of paper 201 fall and are stored inside the waste box 16 disposed below the cutter section 40.

[0033] (Conveyance path) The conveyance path 80 is a path through which the sheets of paper 201, 203 are conveyed. First, a portion of the conveyance path 80 through which the single-sheet paper 201 is conveyed will be described.

[0034] The portion of the conveyance path 80 through which the single-sheet paper 201 is conveyed includes a paper feed path 81, a print path 82, a discharge path 83, a front discharge path 84, an upper discharge path 85, a print upstream path 86, and a print downstream path 87, as indicated by the dashed-dotted line in FIGS. 2 and 3.

[0035] The paper feed path 81 extends upward from the front end of the single-sheet paper storage section 21, turns back and extends rearward and downward in a space formed in front of the roll paper storage section 22 and behind the front middle cover 14, passes above the roll paper storage section 22 and below the single-sheet paper storage section 21, extends toward the rear of the roll paper storage section 22, and is formed up to a position that rises upward behind the roll paper storage section 22.

[0036] Note that, as described later, the paper feed path 81 has a space S that expands in the thickness direction of the sheet of paper 201 so that the conveyed single-sheet paper 201 can pass through without catching the bent portion K of the sheet of paper 201 in the state where it bulges in a mountain shape in the thickness direction.

[0037] The printing path 82 follows the paper feeding path 81 and extends upward so as to rise along the rear of the roll paper storage section 22 behind the roll paper storage section 22, and further extends forward above the roll paper storage section 22 to the front part above the roll paper storage section 22. The above-described printing section 30 is disposed on the printing path 82.

[0038] The discharge path 83 follows the printing path 82 and extends forward along the front-rear direction L from the front part above the roll paper storage section 22. The above-described cutter section 40 is disposed on the discharge path 83. The discharge path 83 extends to a position in front of the cutter section 40.

[0039] The front discharge path 84 follows the discharge path 83 and extends forward to the front discharge port 13a. The upper discharge path 85 follows the discharge path 83 and extends upward and rearward to the upper discharge port 13b.

[0040] A discharge path switching member 71 is provided at the branch portion between the front discharge path 84 and the upper discharge path 85 to switch the sheets 201, 203 that have advanced through the discharge path 83 to advance to the upper discharge path 85 or to the front discharge path 84.

[0041] The upstream printing path 86 follows the printing path 82 and extends from the front part above the roll paper storage section 22 concentrically with the outer periphery of the roll paper storage section 22 downward to a position in front of hitting against the paper feeding path 81. The upstream printing path 86 is a path through which the unprinted portion of the sheet 201 is drawn before being sent to the printing path 82 and printed by the printing section 30. The downstream printing path 87 described later is a path through which the sheet 201 that has been sent to the printing path 82 and printed by the printing section 30 is sent.

[0042] That is, the upstream printing path 86 is passed through by the unprinted portion of the sheet 201, and the downstream printing path 87 is passed through by the portion of the sheet 201 that has already been printed.

[0043] A print discharge switching flap 72 is provided at the branch portion between the print upstream path 86 and the discharge path 83. The print discharge switching flap 72 is rotatably provided so that the tip can be displaced vertically, and rotates under the control of the control unit 95. In the state shown in FIG. 2, the tip of the print discharge switching flap 72 is disposed on the lower side. At this time, the sheet 201 that has advanced forward in the print path 82 is switched to advance to the discharge path 83. On the other hand, in the state where the tip of the print discharge switching flap 72 is disposed on the upper side, the sheet 201 that has advanced forward in the print path 82 is switched to advance to the print upstream path 86.

[0044] The print downstream path 87 extends from the rear to the front below the roll paper storage unit 22, below the paper feed path 81, and above the single-sheet paper storage unit 21 following the end of the print path 82 on the paper feed path 81 side. The front tip of the print downstream path 87 rises upward and is formed to smoothly merge with the paper feed path 81 that also rises upward.

[0045] Note that printing is performed on the surface of the sheet 201 that contacts the ink ribbon 32 in the print path 82, that is, the surface facing the rear in the front-rear direction L in FIGS. 2 and 3. The printed surface in the print path 82 faces downward in the height direction H when the sheet 201 is conveyed to the print downstream path 87.

[0046] When the sheet 201 is conveyed forward through the print downstream path 87 and merges with the paper feed path 81 that rises upward and is conveyed through the paper feed path 81, the printed surface faces upward in the height direction H below the roll paper storage unit 22.

[0047] Furthermore, when the sheet 201 is conveyed rearward along the paper feed path 81 and then conveyed along the print path 82 that rises upward, the printed surface faces forward in the front-rear direction. That is, the sheet 201 merges from the print downstream path 87 into the paper feed path 81 and is conveyed along the paper feed path 81, resulting in a state where the front and back surfaces are reversed. Therefore, the path from the print downstream path 87 to the paper feed path 81, including the paper feed path 81, forms a reversing path that reverses the front and back surfaces of the sheet 201 after the front surface printing is completed.

[0048] Next, a portion of the conveyance path 80 where the sheet 203 unwound from the roll paper 202 is conveyed will be described. The portion of the conveyance path 80 where the sheet 203 unwound from the roll paper 202 is conveyed is provided with a roll paper feed path 89, as shown by the dashed-dotted line in FIGS. 2 and 3, in addition to the portion where the above-described single-sheet paper 201 is conveyed.

[0049] The roll paper feed path 89 extends rearward from approximately the lowermost part of the roll paper 202 housed in the roll paper storage section 22 and is formed up to a position that rises upward behind the roll paper storage section 22.

[0050] A paper feed switching flap 73 is provided at the portion where the paper feed path 81 and the roll paper feed path 89 merge. The paper feed switching flap 73 is rotatably provided so that the tip can be displaced back and forth. In the state shown in FIG. 2, the paper feed switching flap 73 is biased forward at the tip by a spring (not shown in detail). The sheet 201 conveyed along the paper feed path 81 advances to the print path 82, and the sheet 201 conveyed from the print path 82 advances to the print downstream path 87.

[0051] On the other hand, when the sheet 203 unwound from the roll paper 202 and conveyed along the roll paper feed path 89 advances toward the print path 82, the sheet 203 presses the tip of the paper feed switching flap 73 to the rear against the biasing force of the spring and advances to the print path 82.

[0052] When the sheet 203 unwound from the roll paper 202 is printed at the printing section 30 of the printing path 82, since the sheet 203 remains not separated from the roll paper 202, the paper feed switching flap 73 remains pressed to the rear side within the range where the tip can be displaced by the portion of the sheet 203 passing through the roll paper feed path 89.

[0053] (Conveying means) The conveying means 70 includes a single-sheet paper feeding roller 77a, a paper feed roller 77b, a reversing roller 77c, a grip roller 77d, a feed roller 77e, a first discharge roller 77f, a second discharge roller 77g, and a roll paper feeding roller 77h. These conveying rollers 77a - 77h are driven by, for example, a single motor, but may be individually driven by two or more motors.

[0054] Each of these conveying rollers 77a - 77h contacts at least one of the single-sheet paper 201 and the sheet 203 on either the front or back surface, and is rotated by a motor driven under the control of the control unit 95 to convey the sheets 201, 203 along the conveyance path 80.

[0055] The single-sheet paper feeding roller 77a is disposed above the vicinity of the front end of the single-sheet paper storage section 21. The single-sheet paper feeding roller 77a contacts the uppermost single-sheet paper 201 among the single-sheet papers 201 stored in the single-sheet paper storage section 21, and feeds out that single-sheet paper 201 to the paper feed path 81 by rotation. Note that the single-sheet paper feeding roller 77a can rotate in the direction opposite to the feeding direction to pull back the single-sheet paper 201 fed out to the paper feed path 81 into the single-sheet paper storage section 21.

[0056] The paper feed roller 77b is disposed in the paper feed path 81 close to the single-sheet paper feeding roller 77a. The paper feed roller 77b contacts the single-sheet paper 201 fed out to the paper feed path 81 by the single-sheet paper feeding roller 77a, and conveys the single-sheet paper 201 upward along the paper feed path 81. Note that the paper feed roller 77b can also rotate in the direction opposite to the above-described conveying direction to pull back the single-sheet paper 201.

[0057] The reversing roller 77c, the gripper roller 77d, the feed roller 77e, the first discharge roller 77f, the second discharge roller 77g, and the roll paper feeding roller 77h described below can also rotate in the direction opposite to each conveyance direction, like the sheet feeding roller 77b, and can pull back the sheet 201.

[0058] The reversing roller 77c is disposed in a portion of the sheet feeding path 81 above the sheet feeding roller 77b. The reversing roller 77c contacts the sheet 201 that has advanced through the sheet feeding path 81 by the sheet feeding roller 77b, and conveys the sheet 201 along the sheet feeding path 81 toward the printing path 82.

[0059] The gripper roller 77d is disposed in a portion of the printing path 82 close to the sheet feeding path 81 and at a position ahead of the tip of the sheet feeding switching flap 73. The gripper roller 77d contacts the sheet 201 conveyed to the printing path 82, and conveys the sheet 201 through the printing unit 30 toward the discharge path 83 or the upstream printing path 86. At this time, the sheet feeding switching flap 73 is switched to the front side, allowing the sheet 201 conveyed through the sheet feeding path 81 to be conveyed to the printing path 82.

[0060] The feed roller 77e is disposed in a portion of the discharge path 83 closer to the printing path 82 than the cutter unit 40. The feed roller 77e contacts the sheet 201 conveyed to the discharge path 83, and conveys the sheet 201 through the cutter unit 40 to the first discharge roller 77f.

[0061] The first discharge roller 77f is disposed near the end of the discharge path 83 on the side far from the printing path 82 and in front of the discharge path switching member 71. The first discharge roller 77f contacts the sheet 201 conveyed to the discharge path 83, and conveys the sheet 201 to the front discharge path 84 or the upper discharge path 85 according to the position of the discharge path switching member 71.

[0062] The second discharge roller 77g is disposed near the upper discharge port 13b in the upper discharge path 85. The second discharge roller 77g contacts the single-sheet paper 201 conveyed to the upper discharge path 85 and discharges the single-sheet paper 201 from the upper discharge port 13b to the stacker 12a of the upper cover 12.

[0063] The roll paper feed roller 77h is disposed at a position on the roll paper feed path 89 closer to the printing path 82 and in front of the tip of the paper feed switching flap 73. The roll paper feed roller 77h contacts the paper 203 wound around the outermost periphery of the roll paper 202 accommodated in the roll paper storage unit 22 and feeds the paper 203 toward the grip roller 77d by rotation.

[0064] Note that the roll paper feed roller 77h can rotate in a direction opposite to the feeding direction and wind back the paper 203 fed toward the grip roller 77d onto the roll paper 202 in the roll paper storage unit 22.

[0065] (Sensor) As shown in FIGS. 2 and 5, the printer 100 includes a first sensor 96 that detects the passage of the leading end 201a in the feeding direction of the sheet 201 when the sheet 201 is sent to the upstream printing path 86 by the grip roller 77d at a position on the path of the printing path 82 closer to the upstream printing path 86 than the grip roller 77d.

[0066] The printer 100 also includes a second sensor 97 that detects the passage of the trailing end in the feeding direction of the sheet 201 when the sheet 201 is sent to the upstream printing path 86 by the grip roller 77d at a position on the path of the printing path 82 closer to the downstream printing path 87 than the grip roller 77d.

[0067] (Skew correction mechanism) Next, the serpentine correction mechanism 50 will be described with reference to FIGS. 6 to 11. FIGS. 6, 7, and 8 show the state before correcting the serpentine of the sheet 201. FIG. 6 is a perspective view, FIG. 7 is a plan view, and FIG. 8 is a schematic diagram of FIG. 7. FIGS. 9, 10, and 11 show the state in which the serpentine of the sheet 201 is being corrected. FIG. 9 is a perspective view corresponding to FIG. 6, FIG. 10 is a plan view corresponding to FIG. 7, and FIG. 11 is a schematic diagram corresponding to FIG. 8.

[0068] The serpentine correction mechanism 50 corrects the serpentine of the sheet 201 that is conveyed on the conveyance path 80 and skews or changes its direction with respect to the conveyance direction. As shown in FIG. 6, the serpentine correction mechanism 50 includes a paper feed path 81 (an example of a conveyance path), a reverse roller 77c (an example of a driving roller), a grip roller 77d (an example of a downstream roller), a pair of left and right guide members 51, a pair of left and right movable guide members 52, and a pair of left and right cam members 53.

[0069] Here, the reverse roller 77c is provided in the upstream region of the paper feed path 81 in the feeding direction of the sheet 201. The reverse roller 77c is configured to be movable between a grip position where it contacts the sheet 201 to restrain the sheet 201 and a retracted position where it separates from the sheet 201 to release the restraint of the sheet 201.

[0070] The grip roller 77d is provided on the print path 82. Since the print path 82 is provided downstream of the paper feed path 81 in the feeding direction of the sheet 201, the grip roller 77d is provided downstream of the paper feed path 81 in the feeding direction of the sheet 201. Similar to the reverse roller 77c, the grip roller 77d is configured to be movable between a grip position where it contacts the sheet 201 passing through the paper feed path 81 to restrain the sheet 201 and a retracted position where it separates from the sheet 201 to release the restraint of the sheet 201.

[0071] Note that the distance between the inversion roller 77c and the grip roller 77d along the paper feed path 81 is shorter than the length of the single-sheet paper 201. Therefore, when the leading end 201a of the single-sheet paper 201 fed in the feeding direction along the paper feed path 81 by the inversion roller 77c reaches the grip roller 77d, the trailing end of the single-sheet paper 201 is at a position where it can contact the inversion roller 77c.

[0072] A pair of left and right guide members 51 provided to be distributed in the width direction W are respectively fixed and provided on both side edges of the paper feed path 81 as shown in FIG. 7. Each guide member 51 is located outside both side edges of the single-sheet paper 201 passing through the paper feed path 81 and is formed to have a wall surface rising perpendicularly in the thickness direction of the single-sheet paper 201 from the surface of the paper feed path 81. Thereby, the guide member 51 guides the paper 201 by restricting the positions of both side edges of the single-sheet paper 201 in contact with the wall surfaces where the side edges of the single-sheet paper 201 passing through the paper feed path 81 rise.

[0073] Each guide member 51 is formed to have a first portion 51b located on the upstream side in the feeding direction of the paper 201 indicated by an arrow in FIG. 7 and a second portion 51a located on the downstream side.

[0074] As shown in the schematic diagram of FIG. 8, for the pair of left and right first portions 51b, the upstream side portion 51c closest to the inversion roller 77c is formed with an interval L2 (L2 is, for example, 207 [mm]) wider than the width W1 of the paper 201, and the downstream side portion 51d closest to the second portion 51a has an interval L1 substantially equal to the width W1 of the single-sheet paper 201. The interval is gradually narrowed toward the feeding direction (indicated by an arrow) of the single-sheet paper 201 and extends from the first region a1 to the second region a2. In this example, the first portion 51b and the second portion 51a are integrally formed. The pair of first portions 51b in the present embodiment are formed such that the interval gradually becomes narrower linearly, but is not limited to those formed to gradually become narrower linearly.

[0075] On one hand, the second part 51a is formed parallel to the feed direction at an interval L1 (L1 is, for example, 203 [mm]) that is approximately equal to the width W1 of the sheet 201, and is connected to the downstream part of the first part 51b where the interval is the narrowest.

[0076] In addition, when the region between the inversion roller 77c (the rotation center of the inversion roller 77c) and the second part 51a (the central part along the feed direction) is bisected into an upstream first region a1 and a downstream second region a2 in the feed direction, that is, when it is bisected into a first region a1 close to the inversion roller 77c and a second region a2 close to the second part 51a, among the first part 51b, the upstream part 51c closest to the inversion roller 77c is located in the first region a1, and the downstream part 51d closest to the second part 51a is arranged to be located in the second region a2.

[0077] In this way, since the part of the first part 51b closest to the inversion roller 77c with an interval L2 wider than the width W1 of the sheet 201 is located in the first region a1, the sheet 201 sent by the inversion roller 77c is almost surely sent into the first part 51b. Then, the sheet 201 is guided and conveyed by the first part 51b to the second part 51a with an interval L1 approximately equal to the width W1 of the sheet 201.

[0078] In the example shown in FIG. 8, in the first part 51b, the downstream part 51d farthest from the second part 51a extends to the second region a2.

[0079] A pair of left and right movable guide members 52 provided distributed in the width direction W are respectively provided on both side edges of the paper feed path 81 on the upstream side of the feed direction of the sheet 201 and on the downstream side of the inversion roller 77c, as shown in FIG. 7. The movable guide members 52 are also respectively provided on both sides of the paper feed path 81, as shown in FIG. 7.

[0080] Incidentally, the positions of the pair of left and right movable guide members 52 and the reversing roller 77c in the conveyance direction may be swapped, such that the reversing roller 77 is disposed on the downstream side of the movable guide member 52 and the movable guide member 52 is disposed on the upstream side of the reversing roller 77. Even if these positions are swapped, the same configuration and operation as in the case where they are not swapped can be applied.

[0081] The pair of movable guide members 52 are formed in parallel along the feeding direction. Further, the pair of movable guide members 52 are each provided slidably in the axial direction on a common single shaft 52a. This shaft 52a is fixed to the center of a pair of left and right cam members 53 described later. Both ends of the shaft 52a are rotatably held by the left and right frame side plates 56.

[0082] The movable guide member 52 is located outside both side edges of the sheet 201 passing through the paper feed path 81, and is formed with a wall surface that rises vertically in the thickness direction of the single-sheet paper 201 from the surface of the paper feed path 81. Each movable guide member 52 is provided movably in the width direction W along the shaft 52a between a position away from the side edge of the single-sheet paper 201 passing through the paper feed path 81 and a position in contact with both side edges of the single-sheet paper 201.

[0083] Specifically, the pair of movable guide members 52 are provided movably between an interval L2 wider than the width W1 of the single-sheet paper 201 and an interval L1 substantially equal to the width W1 of the single-sheet paper 201. When at the interval L1 substantially equal to the width W1 of the single-sheet paper 201, it becomes a position in contact with both side edges of the single-sheet paper 201.

[0084] Incidentally, the position where the pair of movable guide members 52 are in contact with both side edges of the single-sheet paper 201 is set as a position where each movable guide member 52 is disposed on an extension line along the front-rear direction L of the downstream portion 51a of the guide member 51. Further, the position when the pair of movable guide members 52 are at an interval L2 wider than the width W1 of the single-sheet paper 201 is set as a position where the movable guide member 52 is disposed on an extension line along the front-rear direction L of the upstream end of the upstream portion 51b of the guide member 51.

[0085] Among the movable ranges of the pair of movable guide members 52, an adjustment mechanism may be further provided to regulate the positions of the pair of movable guide members 52 when they move toward the sides in contact with both side edges of the single-sheet paper 201 and to adjust the positions of the movement. This adjustment mechanism includes, for example, a pair of contact portions that contact the inner surfaces of the pair of movable guide members 52 respectively, and a fixing portion that is fixed at any one position or a plurality of positions in the width direction W (a direction perpendicular to the conveyance direction) of the single-sheet paper 201. The adjustment mechanism can be constituted by a plate-shaped regulating member (such as an adjustment plate) disposed between the pair of movable guide members 52 and fixing means (such as fixing screws) for fixing this regulating member. The fixing portion is, for example, a long hole extending in the width direction W of the single-sheet paper 201, and a fixing screw as the fixing means is inserted into this long hole.

[0086] Thereby, when the pair of movable guide members 52 move to contact both side edges of the single-sheet paper 201, the positions where the pair of movable guide members 52 move to the both side edge sides of the single-sheet paper 201 and stop can be adjusted so that the single-sheet paper 201 is corrected to a normal posture at a position where it does not shift with respect to the downstream end portion in the feeding direction in the second portion 51a of the guide member 51.

[0087] The regulating member may be provided separately as a regulating member for one of the pair of movable guide members 52 and a regulating member for the other of the pair of movable guide members 52, rather than being a single member.

[0088] Furthermore, when the pair of movable guide members 52 are at an interval L2 wider than the width W1 of the single-sheet paper 201, the positions may be wider than the positions where the movable guide members 52 are disposed on the extension line along the longitudinal direction L of the upstream end portion of the upstream portion 51b of the guide member 51.

[0089] A pair of cam members 53 are respectively fixed to the shaft 52a on the outer side of the width direction W of the movable guide member 52. The cam member 53 is integrally rotatable about the shaft with the shaft 52a. Each cam member 53 is formed by integrally forming a first cam 53a and a second cam 53b. The first cam 53a is formed on the outer peripheral surface of the cam member 53. The cam surface of the first cam 53a is in contact with a driven member 55 provided integrally with the movable guide member 52. When the cam member 53 rotates, the first cam 53a displaces the driven member 55 biased inward in the width direction W by a spring 57 outward in the width direction W, thereby moving the movable guide member 52 in the width direction W.

[0090] Therefore, the first cam 53a is an example of a moving member that moves the movable guide member 52 in the width direction W between a position with an interval L2 wider than the width W1 of the sheet 201 and a position with an interval L1 substantially equal to the width W1 of the sheet 201.

[0091] The second cam 53b is formed on the inner peripheral surface of the cam member 53. The second cam 53b is in contact with a link plate 54 that supports the shaft 77c1 of the inversion roller 77c. The link plate 54 is rotatably supported about a shaft 77c2 supported by the left and right frame side plates 56. When the cam member 53 rotates about the shaft 52a, the second cam 53b displaces the link plate 54 outward in the radial direction of the cam member 53. As a result, the link plate 54 rotates about the shaft 77c2 and moves the inversion roller 77c supported by the shaft 77c1 from a position in contact with the sheet 201 to a retracted position.

[0092] Therefore, the second cam 53b is an example of a retracting member that retracts the inversion roller 77c at the grip position in contact with the sheet 201 to a retracted position away from the sheet 201 in a state where the leading end 201a in the feeding direction of the sheet 201 reaches the downstream portion 51a of the guide member 51.

[0093] In this way, the cam member 53 interlocks the movable guide member 52 and the reverse roller 77c. Specifically, when the cam member 53 is in the first rotational position, the reverse roller 77c is in contact with the single sheet 201, and the movable guide member 52 is at a position separated from both side edges of the sheet 201 by the interval L2. On the other hand, when the cam member rotates to the second rotational position, the reverse roller 77c is in the retracted position where it does not contact the single sheet 201, and the movable guide member 52 is at a position in contact with both side edges of the single sheet 201 with the interval L1.

[0094] Note that as soon as the cam member 53 starts to rotate from the first rotational position toward the second rotational position, the reverse roller 77c is separated from the single sheet 201, so before the cam member 53 reaches the second rotational position, the reverse roller 77c reaches the retracted position.

[0095] On the other hand, even when the cam member 53 starts to rotate from the first rotational position toward the second rotational position and the reverse roller 77c has reached the retracted position, the movable guide member 52 only narrows slightly from the interval L2, and it is only when the cam member 53 reaches the second rotational position that it becomes the interval L1 and comes into contact with both side edges of the single sheet 201.

[0096] That is, when the cam member 53 rotates from the first rotational position toward the second rotational position, first, the reverse roller 77c separates from the sheet 201 and releases the restraint on the rear end 201b side of the single sheet, and then as the rotation progresses, the movable guide member 52 comes into contact with both side edges of the single sheet 201.

[0097] The cam member 53 is rotated between the first rotational position and the second rotational position under the control of the control unit 95 of the printer 100.

[0098] (Reverse Roller Retraction Control During Printing) Next, the control by the control unit 95 for moving (retracting) the reverse roller 77c to the retracted position will be described.

[0099] As will be described later, in the printing process of the single-sheet paper 201 by the printing unit 30 of the printer 100, under the control of the control unit 95, the single-sheet paper 201 is once sent to the upstream printing path 86 through the printing path 82. At this time, the single-sheet paper 201 passes through the printing path 82, but no printing is performed on the single-sheet paper 201. Then, by reversing the feeding direction of the single-sheet paper 201 and controlling the printing unit 30 while passing the single-sheet paper 201 through the printing path 82 by the rotation of the grip roller 77d, printing is performed on the single-sheet paper 201.

[0100] In this printing process, the portion of the single-sheet paper 201 where printing is performed on the printing path 82, that is, the portion on the leading end side in the feeding direction of the single-sheet paper 201, is sent from the printing path 82 to the downstream printing path 87.

[0101] Here, the length along the downstream printing path 87 between the grip roller 77d that feeds the single-sheet paper 201 on the printing path 82 and the reversing roller 77c provided in the paper feeding path 81 where the downstream printing path 87 merges is set shorter than the length in the feeding direction of the single-sheet paper 201. The intervals between the other conveying rollers 77a to 77h are the same.

[0102] In this way, in order for the conveying means 70 that conveys the single-sheet paper 201 to perform the transfer of the single-sheet paper 201 conveyed along the conveying path 80 by the respective conveying rollers 77a to 77h that constitute the conveying means 70, the pitch between two conveying means 70 adjacent to each other along the conveying path 80 is shorter than the length of the single-sheet paper 201 to be transferred.

[0103] For this reason, when the leading end 201a side in the feeding direction of the single-sheet paper 201 sent to the downstream printing path 87 by the grip roller 77d reaches the reversing roller 77c, it may happen that the area on the trailing end 201b side of the single-sheet paper 201 is still passing through the printing unit 30.

[0104] In this way, when the leading edge 201a of the sheet-fed paper 201 during the printing process comes into contact with the reversing roller 77c, if there is even the slightest difference between the rotational speed of the grip roller 77d and the rotational speed of the reversing roller 77c, the feeding speed of the sheet-fed paper 201 will instantaneously change. In this case, due to the influence of the change in the feeding speed, a slight positional deviation (print unevenness) of the print may occur in the portion of the sheet-fed paper 201 being printed by the printing unit 30.

[0105] Therefore, the printer 100 moves the reversing roller 77c, which the leading edge 201a of the sheet-fed paper 201 being fed by the grip roller 77d and being printed by the printing unit 30 will contact, to a retracted position where it does not contact the sheet-fed paper 201 under the control of the control unit 95.

[0106] That is, the printer (printer 100 in the embodiment) has a printing unit (printing unit 30) that prints on a sheet (sheet-fed paper 201), a first driving roller (grip roller 77d) that passes the sheet through the printing unit, and a second driving roller (reversing roller 77c) provided downstream of the printing unit and the first driving roller in the feeding direction of the sheet, and the second driving roller is movable to a retracted position where it does not contact the sheet being printed by the printing unit.

[0107] In this way, the printer 100 can prevent print unevenness from occurring on the sheet-fed paper 201 by the reversing roller 77c not contacting the sheet-fed paper 201 being printed.

[0108] Also, the above printer has a paper feeding path (paper feeding path 81) that reverses the front and back surfaces of the sheet and feeds the sheet to the printing unit on the downstream side in the feeding direction of the conveyance path (printing downstream path 87) through which the sheet printed by the printing unit passes, and the second driving roller is a reversing roller (reversing roller 77c) that feeds the printed sheet sent through the paper feeding path back to the paper feeding path.

[0109] Further, the printer is provided such that the second drive roller is close to a paper feed roller that feeds the paper fed out from a paper tray (sheet paper storage unit 21), and is a drive roller (paper feed roller 77b) that feeds the paper fed by the paper feed roller to the paper feed path. The paper feed roller and the second drive roller are driven by a single motor.

[0110] In the printer 100 that drives the paper feed roller 77b and the reverse roller 77c with a single motor, the rotation directions of the paper feed roller 77b and the reverse roller 77c are always the same.

[0111] Here, for example, when two sheet papers 201 are stacked and fed to the paper feed path 81 from the sheet paper storage unit 21 (when double feeding occurs), by controlling the rotation direction of the paper feed roller 77b in the opposite direction, only one of the two sheet papers 201 that are double fed can be pulled back to the sheet paper storage unit 21.

[0112] However, when the reverse roller 77c also rotates together with the paper feed roller 77b, the two double-fed sheet papers 201 are both pulled back to the sheet paper storage unit 21, and the double-feed state cannot be eliminated.

[0113] Here, in a printer configured to drive the paper feed roller 77b and the reverse roller 77c with separate motors, only the paper feed roller 77b can be rotated in the opposite direction, but in a printer that drives the paper feed roller 77b and the reverse roller 77c with a single motor, only the paper feed roller cannot be rotated in the opposite direction.

[0114] However, since the printer 100 can move the reverse roller 77c to a retracted position where it does not contact the single-sheet paper 201, even if the paper feed roller 77b and the reverse roller 77c are driven by a single motor, with the reverse roller 77c moved to the retracted position, by rotating the paper feed roller 77b and the reverse roller 77c in opposite directions, the rotation of the reverse roller 77c is not transmitted to the paper 201, and only the rotation of the paper feed roller 77b can be transmitted to the single-sheet paper 201.

[0115] Therefore, even if the printer 100 is configured to drive the paper feed roller 77b and the reverse roller 77c with a single motor, with the reverse roller 77c moved to the retracted position, by rotating the paper feed roller 77b in the opposite direction, the rotation of the paper feed roller 77b can pull back only one of the two double-fed single-sheet papers 201 into the single-sheet paper storage section 21, thereby eliminating the double-feed state.

[0116] (Paper guide opening / closing mechanism) Next, an opening / closing mechanism of a paper guide 90 that covers the conveyance path 80 will be described with reference to FIGS. 12 to 16. FIG. 12 is a perspective view of a main part showing the state where the paper guide 90 is closed, and FIG. 13 is a perspective view of a main part showing the state where the paper guide 90 is open.

[0117] Further, FIG. 14 is a cross-sectional view of a main part showing the state where the paper guide 90 is closed and the reverse roller 77c is in contact with the single-sheet paper 201, FIG. 15 is a cross-sectional view of a main part showing the state where the paper guide 90 is closed and the reverse roller 77c is separated from the single-sheet paper 201, and FIG. 16 is a cross-sectional view of a main part showing the state where the paper guide 90 is open.

[0118] The paper guide 90 is a partition plate that partitions the conveyance path 80 in the thickness direction of the single-sheet paper 201 and covers the conveyance path 80. In the printer 100 of the present embodiment, as shown in FIGS. 1 and 3, it is arranged so as to partition the outer peripheral side of the reversing section, which is a curved region including the reverse roller 77c, spanning from the print downstream path 87 to the paper feed path 81.

[0119] As shown in FIG. 12, the paper guide 90 is configured to be openable and closable so as to switch between a closed state that covers the conveyance path 80 (an inversion section which is a curved region including the inversion roller 77c spanning from the print downstream path 87 to the paper feed path 81) and an open state that exposes this inversion section as shown in FIG. 13. Note that the opening and closing of the paper guide 90 is manually performed by the user.

[0120] The paper guide 90 includes a cover plate 91 and side plates 92 provided integrally with the cover plate 91 on both side portions of the cover plate 91, respectively. The cover plate 91 is formed like a part of the circumferential surface of a cylinder and covers the inversion section from the outer peripheral side as shown in FIGS. 14 and 15. Each side plate 92 is formed to rise upward with respect to the cover plate 91 toward the outside of the circumferential surface of the cylinder.

[0121] Each side plate 92 is supported by a shaft 77c2 which is the rotation center of the link plate 54. Thereby, the paper guide 90, like the link plate 54, is rotatable about the shaft 77c2, and by this rotation, it is switched between the above-described closed state (FIGS. 12, 14, and 15) and open state (FIGS. 13 and 16).

[0122] Also, each side plate 92 is supported rotatably about the shaft 77c2, like the link plate 54. And a long hole 92a through which a shaft 77c1 that supports the inversion roller 77c passes is formed in each side plate 92. As shown in FIGS. 14 to 16, the shaft 77c1 is disposed on the outer surface side of the cover plate 91 and passes through the long hole 92a formed in each side plate 92.

[0123] The long hole 92a is formed along the range in which the shaft 77c1 moves by allowing the link plate 54 to rotate relatively about the shaft 77c2 in order to allow the link plate 54 to rotate relatively about the shaft 77c2 with respect to each side plate 92.

[0124] Here, the range that allows the relative rotation of the link plate 54 with respect to each side plate 92 is set corresponding to the range of movement of the axis 77c1 (arc-shaped around the axis 77c2) when the paper guide 90 is in the closed state (FIG. 12) and moves between the position where the reversing roller 77c contacts the single-sheet paper 201 (FIG. 14) and the retracted position away from the single-sheet paper 201 (FIG. 15).

[0125] That is, the reversing roller 77c can move between the position where it contacts the single-sheet paper 201 and the retracted position while the paper guide 90 remains in the closed state.

[0126] Two openings 91a are formed in the cover plate 91 along the axial direction of the axis 77c2. These openings 91a are holes through which the reversing roller 77c supported by the axis 77c1 arranged on the outer surface side of the cover plate 91 passes, in order to expose the reversing roller 77c to the conveyance path 80 (paper feed path 81) on the inner surface side of the cover plate 91.

[0127] Note that at the retracted position of the reversing roller 77c, since the reversing roller 77c does not protrude toward the conveyance path 80 side from the inner surface of the cover plate 91, the leading edge of the single-sheet paper 201 during printing is smoothly fed along the inner surface of the cover plate 91 without being caught by the reversing roller 77c due to the retraction control of the reversing roller 77c during printing.

[0128] Also, the reversing roller 77c is not configured as a long single object along the axis 77c1, but is arranged as two objects distributed in the axial direction. And the opening 91a formed in the cover plate 91 is not a single long opening in the axial direction, but is formed in two parts corresponding to the reversing roller 77c.

[0129] <Function> Regarding the printer 100 configured as described above, the operation of printing on the single-sheet paper 201 will be exemplified and described.

[0130] First, by the rotation of the single-sheet paper feed roller 77a (see FIG. 2; the same applies hereinafter), one single-sheet paper 201 stacked on the uppermost layer among the single-sheet papers 201 stored in the single-sheet paper storage unit 21 is fed out to the paper feed path 81, and further, by the rotation of the paper feed roller 77b and the rotation of the reversing roller 77c ahead thereof, it is conveyed through the paper feed path 81.

[0131] At this time, the cam member 53 is in the first rotational position. Therefore, the reversing roller 77c is in a position in contact with the single-sheet paper 201 and restraining the single-sheet paper 201, and the movable guide member 52 is in a position separated from both side edges of the single-sheet paper 201 by the interval L2.

[0132] The single-sheet paper 201 sent through the paper feed path 81 may be in an oblique state with its posture inclined with respect to the feeding direction, or may meander due to uneven frictional force when contacting the reversing roller 77c, etc. Even in such a case, the leading end 201a of the single-sheet paper 201 is sent within the range of the first portion 51b formed at an interval L2 wider than the width W1 of the single-sheet paper 201.

[0133] Since the width of the first portion 51b becomes narrower as it advances in the feeding direction, when the single-sheet paper 201 is obliquely advancing or meandering, before the leading end 201a of the single-sheet paper 201 reaches the connection portion with the second portion 51a having the narrowest width, either the left or right side edge of the single-sheet paper 201 starts to contact the first portion 51b.

[0134] The portion on the leading end 201a side of the single-sheet paper 201 that has contacted the first portion 51b is sent along the inclination of the first portion 51b (an inclination with respect to the feeding direction formed such that the interval gradually becomes narrower toward the second portion 51a). That is, the leading end 201a of the single-sheet paper 201 that was being sent in an obliquely inclined posture is, while remaining in the obliquely inclined posture, supposed to move straight along the feeding direction, but the feeding direction is corrected to follow the first portion 51b, so that the moving direction of the portion on the leading end 201a side becomes deviated from the feeding direction of the rear end 201b side of the single-sheet paper 201.

[0135] That is, the movement direction of the portion on the leading end 201a side of a single sheet of paper 201 is restricted by the first portion 51b, and the portion on the trailing end 201b side is constrained by the reversing roller 77c and moves in the feeding direction while being skewed. As a result, since the movement directions of the portion on the leading end 201a side and the portion on the trailing end 201b side of the sheet of paper 201 are different, non-uniform stress is generated in the intermediate portion between the portion on the leading end 201a side and the portion on the trailing end 201b side in the width direction W.

[0136] As for a single sheet of paper 201, it can no longer maintain a flat state due to this non-uniform stress. In order to eliminate the non-uniform stress, the sheet of paper 201 bends in the thickness direction, and one side in the width direction W (the side where the direction of the leading end 201a is inside in the width direction with respect to the direction of the trailing end 201b) rises in a mountain shape in the thickness direction.

[0137] When the sheet of paper 201 is further fed and the leading end 201a reaches the second portion 51a that is parallel to the feeding direction at an interval L1 equal to the width W1 of the sheet of paper 201, both side edges of the leading end 201a come into contact with the second portion 51a respectively. As shown in FIG. 8, the portion on the leading end 201a side of the sheet of paper 201 is corrected to its original normal posture with both side edges parallel to the feeding direction.

[0138] On the other hand, since the portion on the trailing end 201b side of the sheet of paper 201 is constrained by the reversing roller 77c and remains in a skewed state, an intermediate portion between the portion on the leading end 201a side and the portion on the trailing end 201b side forms a bent portion K that rises greatly in a mountain shape in the thickness direction.

[0139] Note that the state where the sheet of paper 201 rises in a mountain shape means that the sheet of paper 201 is deformed convexly even slightly in the thickness direction from the state where it extends straight in the feeding direction and is flat.

[0140] Also, the mountain shape means that regardless of whether it is visually recognized as a mountain-like shape as long as the sheet of paper 201 is deformed convexly in the thickness direction, and regardless of the height (deformation amount) of the bent portion K and the width of the bent range.

[0141] Here, the sheet feeding path 81 has a space S that expands in the thickness direction of the single-sheet paper 201 and can accommodate the bent portion K of the single-sheet paper 201 that bulges in a mountain shape in the thickness direction. If there is no such space S, the bent portion K is not formed in the single-sheet paper 201 within the sheet feeding path 81 during conveyance, and plastic deformation occurs at other locations of the single-sheet paper 201. For example, when the single-sheet paper 201 being sent in an obliquely inclined posture is guided by the guide member 51, the corner portion on the leading end side in the feeding direction of the single-sheet paper 201 is sent out by the reversing roller 77c while being in contact with the inner wall constituting the guide member 51.

[0142] As a result, the single-sheet paper 201 is deformed such that it bends along this inner wall with a crease formed near the corner portion on the leading end side in the feeding direction. In such a state, the single-sheet paper 201 is likely to jam within the sheet feeding path 81. Even if it can be printed without jamming, it will be in a state with a crease.

[0143] Note that the space S of the sheet feeding path 81 corresponds to the "space that expands in the thickness direction of the single-sheet paper" in the present invention even if the bent portion K of the single-sheet paper 201 is within the height range of the guide member 51 (below the height of the wall surface of the guide member 51).

[0144] Then, before the single-sheet paper 201 is sent and its leading end 201a reaches the grip roller 77d (downstream roller) provided on the downstream side in the feeding direction, under the control of the control unit 95, the grip roller 77d moves to the retracted position and does not contact the single-sheet paper 201.

[0145] With the grip roller 77d moved to the retracted position, under the control of the control unit 95, the reversing roller 77c further feeds the single-sheet paper 201. Then, when the leading end 201a of the single-sheet paper 201 reaches the position where it contacts the grip roller 77d when the grip roller 77d returns to the grip position, the feeding of the single-sheet paper 201 by the reversing roller 77c stops.

[0146] Then, from this state, under the control of the control unit 95, the cam member 53 starts to rotate from the first rotational position toward the second rotational position. As soon as the cam member 53 starts to rotate and moves from the first rotational position, the reversing roller 77c moves away from the single-sheet paper 201 and enters the retracted position. As a result, the portion on the rear end 201b side of the single-sheet paper 201 becomes a free state where the restraint by the reversing roller 77c is released and it can move freely.

[0147] Thereby, as shown in FIG. 11, the single-sheet paper 201, based on the portion on the front end 201a side that has been corrected to the normal posture by being regulated by the second portion 51a, is in a free state. The portion on the rear end 201b side, due to the restoring force (the force for the bent portion K to restore to a flat state) of the bent portion K that bulges in a mountain shape in the middle portion, follows the posture of the portion on the front end 201a side, and both side edges are corrected to the normal posture parallel to the feeding direction.

[0148] In this way, the printer 100 of the present embodiment can correct the overall posture of a single sheet of single-sheet paper 201 to the normal posture where both side edges are parallel to the feeding direction by the action of the guide member 51 and the movement of only the reversing roller 77c moving to the retracted position.

[0149] Under the control of the control unit 95, the printer 100 further rotates the cam member 53 toward the second rotational position. As a result, the distance between the pair of left and right movable guide members 52 is displaced to become narrower. When the cam member 53 reaches the second rotational position, the movable guide members 52 come into contact with both side edges of the single-sheet paper 201, and can correct the posture of the single-sheet paper 201 to the normal posture (the parallel posture where both side edges are along the feeding direction) more reliably.

[0150] That is, as described above, when the front end 201a of the single-sheet paper 201 reaches the position where it contacts when the grip roller 77d returns to the grip position, under the control of the control unit 95, the cam member 53 at the first rotational position (FIGS. 6 and 7) is rotated to the second rotational position (FIGS. 9 and 10).

[0151] As the cam member 53 starts to rotate towards the second rotational position, as shown in FIGS. 9 and 10, the second cam 53b presses the link plate 54 towards the outside in the radial direction of the cam member 53, causing the link plate 54 to rotate around the shaft 77c2 and rotate the shaft 77c1 supported by the link plate 54 forward. As a result, the reversing roller 77c provided on the shaft 77c moves to a retracted position away from the single-sheet paper 201 that was sandwiched between the reversing roller 77c and the reversing driven roller 77c3.

[0152] Then, as the cam member 53 further rotates and reaches the second rotational position, the cam surface of the first cam 53a is displaced towards the inside in the width direction W, and the driven member 55 that is in contact with the cam surface of the first cam 53a and is biased towards the inside in the width direction W by a spring is displaced towards the inside in the width direction W. As a result, the movable guide member 52 integrated with the driven member 55 is also displaced towards the inside in the width direction W, and the pair of movable guide members 52 are narrowed to the interval L1.

[0153] As a result, the pair of movable guide members 52 push the side edges on the rear end 201b side of the single-sheet paper 201 that is not constrained by the grip roller 77d and the reversing roller 77c towards the inside in the width direction W, respectively.

[0154] Here, the interval L2 between the pair of movable guide members 52 is substantially equal to the width W1 of the single-sheet paper 201, and each movable guide member 52 is arranged on the extension line in the front-rear direction L of the downstream portion 51a of the guide member 51.

[0155] Therefore, even if the single-sheet paper 201 is in a state where it has not been completely corrected to the normal posture by the action of the guide member 51 and the retracting operation of the reversing roller 77c described above, the movable guide member 52 pushes the portion on the rear end 201b side of the single-sheet paper 201 towards the inside in the width direction W, so that both side edges on the rear end 201b side of the single-sheet paper 201 come into contact with the movable guide member 52 respectively, and the positions of both side edges are corrected.

[0156] As described above, even when the printer 100 according to the present embodiment cannot correct the single-sheet paper 201 to the normal posture only by the guide member 51, the movable guide member 52 can surely correct the single-sheet paper 201 to the normal posture.

[0157] After the single-sheet paper 201 is corrected to the normal posture, the control unit 95 returns the grip roller 77d from the retracted position to the grip position in contact with the single-sheet paper 201. As a result, the single-sheet paper 201 is restrained by the grip roller 77d in a state where the overall posture is corrected to the normal posture.

[0158] Then, by the control of the control unit 95, the grip roller 77d rotates, and the single-sheet paper 201 is sent from the paper feed path 81 to the print path 82 while maintaining the normal posture.

[0159] After the single-sheet paper 201 is sent to the print path 82, the cam member 53 is returned from the second rotation position to the first rotation position by the control of the control unit 95, the movable guide member 52 is returned to the wide interval L2, and the reverse roller 77c is returned to a position where it can grip the single-sheet paper 201.

[0160] The single-sheet paper 201 that has advanced through the print path 82 is guided to the print upstream path 86 by switching the print discharge switching flap 72.

[0161] When the leading end of the single-sheet paper 201 advances to the abutment of the print upstream path 86, the grip roller 77d reverses (the direction of rotation becomes opposite), and the single-sheet paper 201 advances to the print downstream path 87 while being printed on the front (front) surface of the single-sheet paper 201 at the print unit 30 while being sent through the print path 82.

[0162] The single-sheet paper 201 that has advanced from the print path 82 to the print downstream path 87 and the printing on the surface has been completed has its leading end advancing to the paper feed path 81 and contacting the reverse roller 77c, and is conveyed again through the paper feed path 81 by the rotation of the reverse roller 77c.

[0163] The single-sheet paper 201 sent from the print downstream path 87 to the paper feed path 81 is in a state where the front and back surfaces are reversed. Then, when the reversed single-sheet paper 201 is conveyed through the paper feed path 81, the meandering of the single-sheet paper 201 is corrected again by the meandering correction mechanism 50, and the single-sheet paper 201 is set in a normal posture.

[0164] In this way, the single-sheet paper 201 in the state where the posture is set is guided from the print path 82 to the print upstream path 86.

[0165] In addition, the printer 100 may be provided with the guide member 51 of the meandering correction mechanism 50 described above not only in the paper feed path 81 which is also a path for reversing the front and back surfaces of the single-sheet paper 201 after the printing on the front surface, but also in the print downstream path 87 through which the single-sheet paper 201 with the front surface printed passes. In this case, since the print downstream path 87 corresponds to the conveyance path, the grip roller 77d corresponds to the drive roller, and the reversing roller 77c corresponds to the downstream roller, the pair of left and right guide members 51 are provided at a portion of the print downstream path 87 close to the reversing roller 77c. Note that the guide member 51 may also be provided in the print upstream path 86 and the discharge path 83.

[0166] The single-sheet paper 201 with the meandering corrected proceeds to the print downstream path 87 while being printed on the back surface of the single-sheet paper 201 at the print unit 30 while being returned from the print upstream path 86 to the print path 82.

[0167] The single-sheet paper 201 that has advanced from the print path 82 to the print downstream path 87 and has completed the printing on the back surface passes through the print path 82 with the rotation direction of the grip roller 77d being opposite, the print discharge switching flap 72 is switched, and it is conveyed to the discharge path 83. The single-sheet paper 20 sent to the discharge path 83 is transferred from the grip roller 77d to the feed roller 77e.

[0168] In the discharge path 83, the single-sheet paper 201 advances forward through the cutter unit 40 due to the rotation of the feed roller 77e. The cutter unit 40 cuts off the unnecessary portion at the rear end in the feeding direction of the single-sheet paper 201. The unnecessary portion of the cut single-sheet paper 201 drops into the dustbin 16 (see FIG. 2) and is stored inside the dustbin 16.

[0169] The single-sheet paper 201 with the unnecessary portion at the rear end cut off advances forward due to the rotation of the feed roller 77e and is transferred to the first discharge roller 77f. The single-sheet paper 201 is conveyed by the rotation of the first discharge roller 77f. However, when the discharge path switching member 71 is switched to the lower side at the branch portion, the single-sheet paper 201 is guided to the upper discharge path 85 and is discharged from the upper discharge port 13b to the stacker 12a by the rotation of the second discharge roller 77g disposed near the upper discharge port 13b.

[0170] On the other hand, when the discharge path switching member 71 is switched to the upper side at the branch portion, the single-sheet paper 201 is guided to the front discharge path 84, and the single-sheet paper 201 is discharged from the front discharge port 13a to the outside of the printer 100.

[0171] (Control of Alignment of Prints on Front and Back Surfaces) Here, the control of the feeding of the single-sheet paper 201 by the grip roller 77d driven by the control unit 95 when printing on the front and back surfaces of the single-sheet paper 201 described above will be explained.

[0172] As described above, the printer 100 performs printing by the printing unit 30 while feeding the single-sheet paper 201 in the feeding direction from the printing path 82 to the downstream printing path 87 when printing on the front surface of the single-sheet paper 201 and also when printing on the back surface.

[0173] Here, when the single-sheet paper 201 is reversed from the front side to the back side, the ends in the length direction of the single-sheet paper 201 are also reversed. That is, when one end in the length direction of the single-sheet paper 201 is, for example, end A, and the other end is, for example, end B, when printing on the front side of the single-sheet paper 201, the single-sheet paper 201 is fed with end A as the leading end. However, when the single-sheet paper 201 is reversed between the front and back sides, the leading end in the feeding direction of the single-sheet paper 201 is reversed between end A and end B. Therefore, when printing on the back side of the single-sheet paper 201, the single-sheet paper 201 is fed with end B as the leading end.

[0174] For this reason, if printing is performed either with the leading end in the feeding direction of the single-sheet paper 201 as a reference or with the trailing end in the feeding direction of the single-sheet paper 201 as a reference for both printing on the front side and printing on the back side of the single-sheet paper 201, the printing on the front side of the single-sheet paper 201 will be performed at a position with, for example, end A as a reference, and the printing on the back side of the single-sheet paper 201 will be performed at a position with, for example, end B as a reference.

[0175] And when the length of the printed content (such as an image) is significantly shorter than the length of the single-sheet paper 201 (the length between end A and end B), the printed content will be biased towards end A on the front side of the single-sheet paper 201 and towards end B on the back side of the single-sheet paper 201. That is, the side of the end where the printed content is biased will be different between the front side and the back side of the single-sheet paper 201. And even if an attempt is made to cut the blank area where there is no printed content, the blank areas on the front side and the back side of the single-sheet paper 201 do not match, so it cannot be cut.

[0176] In order to solve such problems, the printer 100 of the present embodiment controls the feeding of the single-sheet paper 201 with a fixed position of the single-sheet paper 201 itself as the reference position for feeding the single-sheet paper, regardless of whether printing is performed on the front side or the back side of the single-sheet paper 201.

[0177] That is, the printer 100 controls the feeding of the single-sheet paper 201 such that the printing content is biased toward the A end or the B end on either the front surface or the back surface of the single-sheet paper 201, with a fixed position of the single-sheet paper 201 itself as the reference for feeding, and the control unit 95 controls the feeding.

[0178] Specifically, as shown in FIG. 2, the printer 100 includes a first sensor 96 and a second sensor 97. Both the first sensor 96 and the second sensor 97 are optical sensors that detect the passage of the single-sheet paper, for example, based on a change in the amount of light due to the passage of the single-sheet paper 201.

[0179] The first sensor 96 is provided at a position on the printing path 82 downstream of the printing unit 30 (closer to the upstream printing path 86). The first sensor 96 detects the leading edge of the single-sheet paper 201 in the feeding direction when the single-sheet paper 201 is sent from the printing path 82 to the upstream printing path 86.

[0180] The second sensor 97 is provided at a position on the upstream side of the printing path 82 (closer to the paper feeding path 81) and upstream of the grip roller 77d. The second sensor 97 detects the leading edge of the single-sheet paper 201 in the feeding direction when the single-sheet paper 201 is sent from the printing path 82 to the downstream printing path 87.

[0181] Then, when printing on the front surface of the single-sheet paper 201, the control unit 25 sets the start position of printing based on the detection result of the first sensor 96, and when printing on the back surface of the single-sheet paper 201, the control unit 25 sets the start position of printing based on the detection result of the second sensor 97.

[0182] Here, when printing on the front surface of the single-sheet paper 201, first, the grip roller 77d sends the single-sheet paper 201 from the printing path 82 to the upstream printing path 86. At this time, the first sensor 96 detects the leading edge (for example, the A end) of the single-sheet paper 201 in the feeding direction.

[0183] When the first sensor 96 detects the A end of the single sheet of paper, the control unit 95 feeds the single sheet of paper 201 to the print upstream path 86 by the gripper roller 77d by a preset first length (for example, let it be length M1).

[0184] The preset first length is set as a predetermined first number of steps for the control unit 95 to drive the stepping motor when the motor for rotating the gripper roller 77d is a stepping motor, for example. The first length is set to be longer (M1 > M0) than the length of the print content printed on the surface (for example, let it be length M0).

[0185] Thereafter, the control unit 95 controls the rotation direction of the gripper roller 77d to be opposite, and while feeding the single sheet of paper 201 from the print path 82 to the print downstream path 87, controls the print unit 30 to start printing on the surface of the single sheet of paper 201. At this time, the leading end in the feeding direction of the single sheet of paper 201 is the B end, but the printing on the surface of the single sheet of paper 201 is performed with the A end of the single sheet of paper 201 as a reference.

[0186] That is, on the surface of the single sheet of paper 201, starting from the position of a predetermined first length from the A end and toward the A end, the print content starts to be printed and is printed by the length of the print content. Therefore, for the single sheet of paper 201, the range from the A end to the position of the length obtained by subtracting the length of the print content from the first length (= M1 - M0) becomes a blank space.

[0187] The single sheet of paper 201 with the printing on the surface completed is fed from the print downstream path 87 to the paper feed path 81 by the reversing roller 77c with the B end as the leading end in the feeding direction, and the front and back surfaces are reversed. The single sheet of paper 201 that is fed through the paper feed path 81 with the B end as the leading end in the feeding direction and is turned over is guided to the print path 82 by the gripper roller 77d and further fed to the print upstream path 86.

[0188] When the A end, which is the rear end of the single-sheet paper 201 in the feeding direction, passes through the second sensor 97, the second sensor 97 detects the rear end (A end) of the single-sheet paper 201. The control unit 95 uses the time when the second sensor 97 detects the A end of the single-sheet paper 201 as the feeding reference, and feeds the single-sheet paper 201 to the printing upstream path 86 with the grip roller 77d by a preset second length (for example, let it be length M2).

[0189] The preset second length is set as a predetermined second number of steps for the control unit 95 to drive the stepping motor when, for example, the motor that rotates the grip roller 77d is a stepping motor.

[0190] Note that the second length is set to be the length obtained by subtracting the length of the printed content from the first length when printing on the surface (M2 = M1 - M0).

[0191] After that, the control unit 95 controls the rotation direction of the grip roller 77d to be opposite, feeds the single-sheet paper 201 from the printing path 82 to the printing downstream path 87, and controls the printing unit 30 to start printing on the surface of the single-sheet paper 201. At this time, the front end in the feeding direction of the single-sheet paper 201 is the A end, but the printing on the back surface of the single-sheet paper 201 is performed with the A end of the single-sheet paper 201 as the reference.

[0192] That is, on the back surface of the single-sheet paper 201, the area from the A end to the position of the predetermined second length (M2) becomes a margin, and the printed content starts to be printed from that second position toward the B end, and is printed by the length of the printed content from the position of the second length from the A end.

[0193] Thereby, the printer 100 can print the surface and the back surface of the single-sheet paper 201 such that the range of the second length (M2) from one end (A end) of the single-sheet paper 201 itself becomes a margin, and the printed content is printed in the range up to the position of the length (M0) of the printed content following that margin.

[0194] Therefore, both the front and back surfaces of the single-sheet paper 201 can have a common margin area in the range from the position at a length of (M2 + M0) from the A end to the B end. Even if this margin area is cut by the cutter unit 40, it will not affect the printed content on the front and back surfaces.

[0195] In this way, the printer 100 includes a grip roller 77d which is a conveying means for feeding the single-sheet paper 201, a printing unit 30 which performs printing on the single-sheet paper 201 while feeding the single-sheet paper 201 in one direction by the grip roller 77d, and a control unit 95 which controls the feeding of the single-sheet paper 201 by setting the reference position for feeding the single-sheet paper 201 as a specific position of the single-sheet paper 201 itself regardless of the front and back surfaces of the single-sheet paper 201 when printing on the front surface of the single-sheet paper 201 and when printing on the back surface of the single-sheet paper 201.

[0196] And the printer 100 uses one end of the single-sheet paper 201 in the feeding direction as the reference position for feeding.

[0197] Furthermore, the printer 100 is provided with a first sensor 96 and a second sensor 97 which respectively detect one end of the single-sheet paper 201 on the upstream side and the downstream side in the feeding direction of the single-sheet paper 201 of the grip roller 77d which is a conveying means. The control unit 95 specifies the reference position for feeding as a specific position by switching and using the detection result by the upstream first sensor 96 and the detection result by the downstream second sensor 97 when printing on the front surface of the single-sheet paper 201 and when printing on the back surface of the single-sheet paper 201.

[0198] <Effect> As described above, the printer 100 of the present embodiment can appropriately correct the posture and orientation of the single-sheet paper 201 by the meandering correction mechanism 50 and correct the meandering of the single-sheet paper 201.

[0199] Further, in the printer 100 of the present embodiment, since the pair of left and right cam members 53 are fixed to the shaft 52a, the left and right cam members 53 can be rotated in conjunction with each other by the rotation of the shaft 52a. As a result, the pair of left and right movable guide members 52 can also be displaced in the width direction W in conjunction with each other.

[0200] Therefore, the printer 100 of the present embodiment can be configured to include only one motor for rotating the shaft 52a, and has a simple structure with fewer parts compared to a configuration in which each movable guide member 52 is provided with a motor to move each movable guide member 52, and can correct the meandering of the single-sheet paper 201.

[0201] Further, in the printer 100 of the present embodiment, the second cam 53b as a retracting member for retracting the reversing roller 77c to a position not in contact with the single-sheet paper 201 and the first cam 53a for moving the movable guide member 52 within the movable range are integrally formed as the cam member 53. Therefore, the movement of the reversing roller 77c (retraction to the retracted position) and the movement of the movable guide member 52 (movement to positions in contact with both side edges of the single-sheet paper 201) can be interlocked.

[0202] The printer 100 of the present embodiment has been described as performing only once the operation of retracting the reversing roller 77c from the single-sheet paper 201 and the operation of pressing both side edges of the single-sheet paper 201 inward in the width direction W by the movable guide member 52. However, the normal rotation and reverse rotation of the cam member 53 between the first rotation position and the second rotation position may be repeated a plurality of times to press both side edges of the single-sheet paper 201 inward in the width direction W a plurality of times.

[0203] Further, by performing the operation of rotating the cam member 53 from the first rotation position to the second rotation position within a short time, the movable guide member 52 can impart an impact so as to strike both side edges of the single-sheet paper 201 inward in the width direction W, and the effect of correcting the meandering of the single-sheet paper 201 can be enhanced.

[0204] Further, the printer 100 of the present embodiment can move the reverse roller 77c to the retracted position (FIG. 15) during printing while keeping the paper guide 90 in the closed state (FIG. 12) without opening it (FIGS. 13 and 16).

[0205] Furthermore, when a jam occurs in the single-sheet paper 201 at the reversing unit, the printer 100 can open the paper guide 90 (FIGS. 13 and 15), so that the reverse roller 77c can also be separated from the reversing unit integrally with the paper guide 90.

[0206] Therefore, when the paper guide 90 is in the open state, the printer 100 can improve the accessibility to the reversing unit compared to a printer configured such that the reverse roller 77c remains in the reversing path, and can easily remove the jammed single-sheet paper 201 in the reversing unit.

[0207] In addition, the openings 91a formed in the cover plate 91 through which the reverse roller 77c passes are distributed in two along the axial direction. In this configuration, a plate surface of the cover plate 91 that is not an opening remains between the two openings 91a. On the other hand, in a configuration formed by a single long opening in the axial direction, the edge of the opening extends long in the axial direction and no plate surface of the cover plate 91 remains.

[0208] Thus, in the case of a configuration in which the opening 91a through which the reverse roller 77c passes is formed by a single long opening in the axial direction, there is no portion in the single opening 91a that supports the single-sheet paper 201 over the long width range of the opening 91a. For example, if the single-sheet paper 201 is easily deformed and biased toward the opening 91a side, the tip 201a of the single-sheet paper 201 is likely to be deformed convexly so as to enter the opening 91a.

[0209] Therefore, in the case where the plate surface of the cover plate 91 is left, compared with the configuration formed by a single long axial opening, the remaining plate surface portion between the two narrow-width openings 91a supports the single-sheet paper 201. Thus, even if the single-sheet paper 201 is likely to be deformed and biased toward the opening 91a side, it is less likely to be deformed enough to enter the narrow-width opening 91a. Therefore, in the case where the plate surface of the cover plate 91 is left, when the leading end 201a of the single-sheet paper 201 being printed passes through the reversing portion with the reversing roller 77c moved to the retracted position, it is possible to reduce the leading end 201a of the single-sheet paper 201 from getting caught on the edge of the opening.

[0210] The printer 100 of the present embodiment shows an example of correcting the skew of the single-sheet paper 201 using the guide member (guide member 51) and the movable guide member (movable guide member 52). However, the printer according to the present invention is not limited to those provided with a movable guide member. That is, depending on its use, if correction of the skew of the single-sheet paper 201 by the guide member (guide member 51) alone is sufficient, the movable guide member (movable guide member 51) may not be provided.

[0211] The printer 100 of the present embodiment is a sublimation type thermal printer. However, the printer according to the present invention is not limited to a sublimation type thermal printer, and may be a printer of another printing format other than a sublimation type thermal printer.

[0212] That is, the printer according to the present invention may be a thermal printer other than the sublimation type, may be an inkjet printer other than a thermal printer, or may be a printer of other printing formats.

[0213] The printer 100 of the present embodiment has been described as performing printing on both sides of the single-sheet paper 201. However, the printer according to the present invention may be a printer that performs printing on only one side of the single-sheet paper.

[0214] The printer 100 of this embodiment is a printer that can perform printing not only on single sheets of paper 201 that have been cut to a predetermined length in advance but also on long roll paper 202. However, the printer according to the present invention may be a printer that performs printing only on single sheets of paper, that is, a printer that cannot accommodate roll paper.

Explanation of Reference Numerals

[0215] 51 Guide member 51b First part 51a Second part 52 Movable guide member 53a First cam 53a 53b Second cam 77c Inversion roller 77d Grip roller 81 Paper feed path 100 Sublimation thermal printer 201 Single sheet of paper (paper) W0 Width of paper L1, L2 Spacing

Claims

1. A conveyance path through which a single sheet of paper passes, A drive roller provided in an upstream region in the sheet feeding direction of the conveyance path for feeding the single sheet of paper along the conveyance path, A downstream roller provided on the downstream side in the feeding direction of the conveyance path for restraining the single sheet of paper that has passed through the conveyance path, A pair of guide members disposed outside both side edges of the single sheet of paper passing through the conveyance path for guiding the single sheet of paper by restricting the positions of both side edges of the single sheet of paper, and comprising: Each of the pair of guide members has a first portion located on the upstream side in the feeding direction and a second portion located on the downstream side, The distance between the pair of guide members is such that the portion of the first portion closest to the drive roller is wider than the width of the single sheet of paper and gradually narrows in the sheet feeding direction, the portion of the first portion closest to the second portion is formed to be the width of the single sheet of paper, and the second portion is formed to be the width of the single sheet of paper, When the region between the drive roller and the second portion is divided into two equal parts, a first region on the upstream side and a second region on the downstream side in the feeding direction, the portion of the first portion closest to the drive roller is arranged to be located in the first region, The conveyance path has a space extending in the thickness direction of the single sheet of paper that can accommodate a bent portion of the single sheet of paper in a mountain-shaped raised state between a front end side portion of the single sheet of paper whose direction has been corrected by being restricted by the second portion and a rear end side portion of the single sheet of paper restrained by the drive roller, A retracting member for retracting the drive roller to a position not in contact with the single sheet of paper in a state where the leading end of the single sheet of paper in the feeding direction has reached the second portion, A movable guide member movably provided between the drive roller and the guide member from a position away from both side edges of the single sheet of paper to a position in contact with both side edges, A printer comprising a moving member for moving the movable guide member within the movable range in a state where the drive roller is retracted.

2. The printer according to claim 1, further provided with an adjustment mechanism for restricting and adjusting the position of movement of the movable guide member toward the side in contact with both side edges of the single sheet of paper within the movable range of the movable guide member.

3. The printer according to claim 1, wherein the retracting member and the moving member are integrally formed to interlock the retraction of the drive roller to a position not in contact with the single sheet of paper and the movement of the movable guide member to positions in contact with both side edges respectively.

4. The printer according to any one of claims 1 to 3, wherein a position where the movable guide member contacts both side edges of the sheet is set as a position arranged on an extension line of the second portion.

5. The printer performs printing on both sides of the sheet, and the conveyance path provided with the guide member is a path that passes when printing is performed on one side of the sheet, and further passes when printing is performed on the other side which is the back side of the one side of the sheet after the printing on the one side of the sheet is completed. The printer according to claim 1.

6. The conveyance path provided with the guide member is a path that passes when printing is performed on the one side and when printing is performed on the other side, and further, the printer according to claim 5, which has two paths: a print downstream path through which the sheet passes after the one side is printed and after the other side is printed.

7. The moving member moves the movable guide member to positions respectively contacting both side edges in a state where the feeding of the sheet is stopped. The printer according to claim 1 or 2.

8. The moving member performs a plurality of operations of moving the movable guide member from a position away from both side edges to positions respectively contacting both side edges in a state where the feeding of the sheet is stopped. The printer according to claim 7.

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