JP6686669B2 - Printer - Google Patents

Description

  The present invention relates to a printing device having a function of separating a medium conveyed by a belt from the belt.

  2. Description of the Related Art Conventionally, there is known a printing apparatus that sucks a sheet on a belt and prints on the sheet (for example, Patent Document 1). In the printing apparatus described in Patent Document 1, a sheet is conveyed by a belt in a path in which printing is performed, and then the sheet is peeled from the belt by a separating claw that comes into contact with the belt and moves to another conveying path. .

JP 2004-338867 A

  By the way, in a printing apparatus in which the conveyor belt is movable, the conveyor belt collides with the separation claw when the conveyor belt returns to the original position (printable position). Therefore, there is a possibility that the belt may be damaged by a collision when the transport belt returns to its original position.

  SUMMARY OF THE INVENTION It is an object of the present invention to provide a printing device capable of suppressing damage to a belt due to a conveyor belt colliding with a separation claw.

Hereinafter, the means for solving the above-mentioned problems and the effects thereof will be described.
A printing apparatus that solves the above problems includes a first transport unit having a transport belt that attracts and transports a medium, a printing unit that performs printing on the medium attracted on the transport belt, and the transport belt. A separation claw that separates the medium from the conveying belt by contacting a claw portion at the tip of the medium suction surface with the separation claw, and the medium separated by the separation claw from the first conveying part. A second transport unit that transports the medium downstream in the transport direction, the separation claw includes a support unit that is rotatably supported, and an arm that extends from the support unit and has the claw unit, The transport belt is supported by a structure other than the first transport unit, and the transport belt is at a position where the transport belt and the separation claw come into contact with each other, and the medium separated from the transport belt by the separation claw is 2 Carry to the transport section When the transfer position is moved from the retracted position to the transport position, the transport belt is movably supported between the transport position and the retracted position at which the transport belt and the separation claw are separated from each other, and the retracted position is retracted from the transport position. The separation claw approaches and comes into contact with the separation claw from a direction intersecting a direction from the support portion to the claw part of the separation claw.

  According to this structure, when the conveyor belt moves from the retracted position to the conveyor position, the conveyor belt does not move toward the claw portion of the separation claw but intersects the direction from the support portion of the separation claw toward the claw portion. Since it moves so as to approach the separation claw from the direction, it is possible to prevent the claw portion at the tip of the separation claw from sticking to the conveyor belt. As a result, damage to the conveyor belt is suppressed.

In the above-mentioned printing apparatus, it is preferable that the transport belt moves from the transport position toward the retracted position when the printing unit is maintained.
With this configuration, when the printing unit is maintained, the transport belt moves from the transport position to the retracted position, and the distance between the printing unit and the transport belt increases, so that the ink that scatters during maintenance of the printing unit. It becomes difficult for such liquids to adhere to the conveyor belt. That is, the contamination of the conveyor belt is suppressed.

In the printing apparatus, it is preferable that the separation claw is supported by the structure located downstream of the transport belt in the transport direction of the medium.
According to this configuration, for example, in a configuration in which the conveyor belt is wound between a pair of upstream and downstream rollers, the upstream roller is rotated to move between the transportation position and the retreat position. However, the separation claw does not hinder the movement of the conveyor belt.

  In the above printing apparatus, it is preferable that the force applied to the claw portion of the separation claw is 0.4 N or less when the conveyance belt moves from the retracted position to the conveyance position and contacts the separation claw.

  According to this configuration, since the force applied to the claw portion of the separation claw is 0.4 N or less, the claw caused by the collision of the conveyor belt with the separation claw is greater than that when the force is greater than 0.4 N. The amplitude of the vibration of the part becomes small, and the time for the vibration to converge becomes short. This suppresses the medium from being caught by the separation claw, as compared with the case where the vibration of the claw portion of the separation claw continues for a long time.

  In the printing apparatus, the separation claw includes the support section, a first arm as the arm that extends from the support section in a direction intersecting a rotation axis of the separation claw, and has the claw section at a tip thereof. It is preferable that the first arm has a second arm extending in a direction different from that of the first arm, and the claw portion at the tip of the first arm is biased to press the transport belt.

  According to this configuration, since the claw portion at the tip of the first arm presses the transport belt, the claw portion of the separation claw is prevented from being separated from the transport belt when the transport belt goes around, and the medium is separated. It prevents the nail from separating.

  In the printing apparatus, it is preferable that the force of the claw portion of the separation claw pressing the transport belt is 0.065 N or more and 0.074 N or less, and the length of the first arm is 28.5 mm. With this configuration, the claw portion of the separation claw presses the conveyor belt with an appropriate force (torque), so that the separation claw portion of the separation claw is less lifted from the conveyor belt and abrasion of the conveyor belt is suppressed. Become so.

  In the printing apparatus, the distance between the load portion of the second arm and the rotation center of the support portion is 8.25 mm, the distance between the claw portion and the rotation center of the support portion is 28.5 mm, and The force applied to the load portion of the second arm is preferably 0.24N.

  According to this configuration, the force with which the claw portion of the separation claw presses the conveyor belt is set to about 0.07N. Moreover, since the length of the second arm is shorter than the length of the first arm and the size of the separation claw is compact, the member supporting the separation claw can be made compact.

FIG. 3 is a sectional view of the printing apparatus according to the embodiment. FIG. 3 is a sectional view of the printing apparatus according to the embodiment. The perspective view of a belt unit and a belt moving part. The side view of a belt unit and a cleaning unit. FIG. 3 is a perspective view of a medium separating unit. Sectional drawing of a medium separation part. FIG. 6 is a cross-sectional view of the medium separating portion showing the operation of the separating claw. FIG. 6 is a cross-sectional view of the medium separating portion showing the operation of the separating claw. FIG. 6 is a cross-sectional view of the medium separating portion showing the operation of the separating claw. 6 is a timing chart showing the relationship between the conveyance of paper, the flushing operation, and the change in the amplitude strength of the separation claw. FIG. 9 is a cross-sectional view of the vicinity of a medium separating unit in a printing apparatus according to another embodiment.

  Hereinafter, as an embodiment of a printing apparatus, an inkjet printer that includes a printing unit that ejects ink that is an example of a liquid and that ejects ink onto a sheet that is an example of a medium to print an image including characters and figures Will be described with reference to the drawings.

  As shown in FIG. 1, a printer 11 as an example of the printing apparatus according to the present embodiment has a housing 12 having a substantially rectangular parallelepiped shape including a plurality of exterior cases as a main body of the apparatus. 1, a conveyance path 13 for conveying the sheet 14 is provided as indicated by a thick chain line. Then, a transport member 15 that can transport the paper 14 along the transport path 13 by contacting the paper 14 and a printing unit 18 that ejects ink to the paper 14 transported by the transport member 15 are provided. Mounted on the housing 12. The transport member 15 is disposed at a plurality of locations on the transport path 13 in the housing 12, and rotates to transport the paper 14 and a plurality of roller members 16, and the paper 14 in the vertical direction Z in the gravity direction −Z side (lower side). And a conveyor belt 51 that supports and conveys from the side).

  The roller member 16 constitutes various rollers respectively arranged in the transport path 13, and, for example, a supply drive roller 30a, a supply driven roller 30b, a transport drive roller 48, a toothed roller 49, etc., which will be described later, are a kind of the roller member 16. Is. The conveyor belt 51 is mounted on the housing 12 in a state where the conveyor belt 51 can be moved to the first position facing the printing unit 18 with the conveyor path 13 in between, that is, in a usable state.

  In the present embodiment, the printing unit 18 prints on the paper 14 adsorbed on the conveyor belt 51 as described later. The printing unit 18 is a so-called line head having a liquid ejection head capable of ejecting ink simultaneously over the longitudinal direction, with the longitudinal direction being a width direction X intersecting (here, orthogonal to) the conveyance direction Y of the paper 14. There is. In order to facilitate the following description, of the width direction X, the left direction (direction facing the front side of the paper) when viewed from the upstream side in the transport direction Y is defined as the + X direction, and viewed from the upstream side in the transport direction Y. And the right direction (direction toward the back side of the paper) is defined as the -X direction.

  The printing unit 18, which is a line head, ejects ink from the position on the anti-gravity direction + Z side (upper side) toward the paper 14 conveyed while being supported by the conveyance belt 51, in the gravity direction −Z. To print. The position of the conveyor belt 51 when the printing unit 18 prints on the paper 14, that is, the first position where the conveyor belt 51 faces the printing unit 18 and conveys the paper 14 is referred to as a printing position IP. The printing position IP is also referred to as a carrying position because the paper 14 is carried. The printing position IP (conveyance position) is a position where the conveyance belt 51 and the separation claw 120 come into contact with each other, and the sheet 14 separated from the conveyance belt 51 is directed toward the second conveyance unit 26B, as described later. It is a position for transporting.

  The transport path 13 includes a first supply path 21 and a second supply path 22 upstream of the printing section 18 in the transport direction Y, and a third supply path 23 and a print path 26 downstream of the printing section 18 in the transport direction Y. , A branch route 24, and a discharge route 25.

  The first supply path 21 is a path that connects the paper cassette 27, which is provided at the bottom of the housing 12 on the −Z side in the direction of gravity, so that the paper cassette 27 can be inserted and removed, and the printing unit 18. Then, in the first supply path 21, the pickup roller 28 that sends out the uppermost sheet 14 of the sheets 14 stacked in the sheet cassette 27 and the sheet 14 that is sent out by the pickup roller 28 A separation roller 29 for separating the sheets one by one is provided. Further, on the downstream side of the separation roller 29 in the transport direction Y, a first supply roller pair 31 for sandwiching and transporting the paper 14 delivered from the paper cassette 27 is provided. The pickup roller 28 and the separation roller 29 are also a kind of the roller member 16.

  The second supply path 22 is a path connecting the insertion section 12b exposed by opening the cover 12a provided on one side surface of the housing 12 and the printing section 18. The second supply path 22 is provided with a second supply roller pair 32 that nips and conveys the sheet 14 inserted from the insertion portion 12b.

  The third supply path 23 is a path provided so as to surround the printing unit 18, and is a path for returning the sheet 14 that has once passed the printing unit 18 to the upstream side of the printing unit 18 again. That is, the branch mechanism 36 is provided on the downstream side of the printing unit 18, and the branch path 24 branched from the discharge path 25 is provided with a pair of branch rollers 37 capable of both forward rotation and reverse rotation. It is provided. The branch roller pair 37 is also a kind of the roller member 16. Further, a third supply roller pair 33 is provided at a position where the first supply path 21, the second supply path 22 and the third supply path 23 merge, and the third supply path 23 has a fifth supply path. A supply roller pair 35 is provided. The first supply roller pair 31 to the third supply roller pair 33 and the fifth supply roller pair 35 are cylindrical supply drive rollers 30a that rotate based on the driving force of a drive source (not shown), and supply. It is configured by a supply driven roller 30b that is rotated by rotation of the drive roller 30a.

  The printing path 26 is a path facing the printing unit 18. The print path 26 includes a first transport unit 26A and a second transport unit 26B on the downstream side of the first transport unit 26A. The first transport unit 26A includes a transport belt 51. The second transport unit 26B is a route that is interposed between the first transport unit 26A and the discharge route 25 and connects the two.

  The ejection path 25 is a path that connects the ejection port 38, through which the printed sheet 14 conveyed by the conveyance belt 51 is ejected, and the printing unit 18. On the upstream side of the discharge path 25, a medium separation unit 110 for separating the sheet 14 conveyed from the conveyor belt 51 from the conveyor belt 51 is arranged.

  The sheet 14 ejected from the ejection port 38 is placed on the placing table 39. Then, the discharge path 25 is provided with at least one transport roller pair (in the present embodiment, the first transport roller pair 41 to the fifth transport roller pair 45). Further, the third supply path 23 is also provided with a sixth transport roller pair 46 and a seventh transport roller pair 47. These first transport roller pair 41 to seventh transport roller pair 47 sandwich and transport the paper 14 to which ink is attached. Further, the third supply roller pair 33 and the fifth supply roller pair 35 may also sandwich and convey the paper 14 to which the ink is attached.

  In the present embodiment, the transport belt 51 facing the printing unit 18 is configured to transport the paper 14 by circling while supporting the paper 14 on the belt surface 51a that is the outer peripheral surface thereof by electrostatic attraction. There is. The conveyor belt 51 is configured as an endless belt stretched between the conveyor belt 51 and the two rollers 52 and 53. The two rollers 52 and 53 are supported by the belt frame body 55. One (upstream side) of the two rollers is a driving roller 52 that is rotationally driven by a driving source, and the other (downstream) roller is a driven roller 53 that rotates as the belt goes around. The conveyor belt 51, the two rollers 52 and 53, and the belt frame body 55 constitute a belt unit 50.

  Further, the charging roller 81 has a rubber layer formed on the surface of a metal roller shaft 81a, and a high pressure is applied by directly contacting a leaf spring (not shown) to the end of the roller shaft 81a. There is. Alternatively, the charging roller 81 is configured such that a bearing portion that receives the roller shaft 81a of the charging roller 81 is a conductive bearing (such as a conductive resin or a sintered bearing), and a high voltage is applied through the conductive bearing. May be. Then, the conveyor belt 51 is rotated along with the rotation of the drive roller 52, and the electrostatic charge is charged on the conveyor belt 51 by the charging roller 81 that is in contact with the belt surface 51a during the rotation. The conveyor belt 51 attracts the sheet 14 to the flat belt surface 51a on the + Z side in the antigravity direction formed between the driving roller 52 and the driven roller 53 by the charged static electricity, and the attracted sheet 14 is printed by the printing unit. The sheet is conveyed in the conveying direction Y while facing 18. Here, it is also understood that the conveyor belt 51 whose belt surface 51a is revolved by the rotation of the drive roller 52 is revolving around the intermediate position between the drive roller 52 and the driven roller 53 in the conveyance direction Y. it can. That is, it can be said that the transport member 15 including the roller member 16 and the transport belt 51 contacts the paper 14 and rotates to transport the paper 14 along the transport path 13.

  In the present embodiment, in the printer 11, the conveyor belt 51 moves the printing position IP where printing is performed by the printing unit 18 to a second position or a third position that is farther from the printing unit 18 than the printing position IP. A moving unit 60 is provided. That is, the belt moving unit 60 has the link member 61 that operates in accordance with the rotational driving of the motor M as the driving source. This link member 61 operates in accordance with the driving of the motor M, and moves the conveyor belt 51 from the printing position IP which is the first position, with the driving roller 52 as the center, as indicated by the double-dashed line arrow in FIG. The driven roller 53 side is swung in the direction of gravity −Z and moved to the second position or the third position which is farther from the printing unit 18 than the printing position IP. For example, the second position is defined as a position where the transport belt 51 rotates (swings) about the drive roller 52 from the printing position IP about 90 degrees. The second position is a position where the conveyor belt 51 is retracted from the first position and the conveyor belt 51 and the separation claw 120 are separated from each other. This second position is called the first retracted position FP. The third position is defined as a position where the transport belt 51 rotates about the drive roller 52 from the printing position IP about 20 degrees. The third position is a position where the transport belt 51 is retracted from the first position and the transport belt 51 and the separation claw 120 are separated from each other. This third position is called the second retracted position SP. Then, in the present embodiment, the belt surface 51a of the conveyor belt 51 has a horizontal posture that is a substantially horizontal plane at the printing position IP, and has a vertical posture that is a substantially vertical surface along the vertical direction Z at the first retracted position FP, and the second posture. At the retracted position SP, the inclined position is inclined at a predetermined angle. When the belt unit 50 swings as the motor M is driven, the positional relationship between the conveyor belt 51 and the separating claw 120 described below changes as follows. That is, when the transport belt 51 moves to the first retracted position FP or the second retracted position SP, the contact portion of the transport belt 51 with which the claw portion 125 contacts moves downward and separates from the separation claw 120. When the transport belt 51 moves toward the printing position IP, the contact portion of the transport belt 51 with which the claw portion 125 abuts is in the direction from the support portion 121 of the separation claw 120 toward the claw portion 125 (horizontal direction in the embodiment). The separation claw 120 is approached from a direction intersecting with (for example, from below). That is, the movement path of the conveyor belt 51 is set so that the contact end 125a of the separation claw 120 does not pierce the belt surface 51a of the conveyor belt 51. The rotational speed of the belt unit 50 (rotational speed during swinging) is configured so that the impact force applied to the claw portion 125 when the transport belt 51 collides with the claw portion 125 of the separation claw 120 is 0.4 N or less. ing. This is for suppressing the deterioration of the claw portion 125 of the separation claw 120 due to the collision.

  In the present embodiment, a flushing operation of ejecting ink is performed for the purpose of maintaining the printing performance (for example, print quality) of the printing unit 18 by suppressing the drying of the ink inside the printing unit 18. For example, the printer 11 is provided with a cap moving mechanism 70 that covers the printing unit 18 by bringing the cap 71 into contact with the printing unit 18 in the non-printing state from the gravity direction −Z side.

  In the cap moving mechanism 70, when the member 72 and the member 73 that hold the cap 71 capable of covering at least the ink ejection portion in the printing unit 18 with the closed space reciprocate along the transport direction Y. The cap 71 is moved (moved up and down) along the vertical direction Z by a link mechanism and a cam mechanism. Then, in a state in which the printing unit 18 is not covered apart from the printing unit 18, the cap 71 and the members (for example, the member 72 and the member 73) that configure the cap moving mechanism 70 are indicated by two-dot chain line arrows in the drawing. As described above, it is arranged at a position where it does not come into contact with the conveyor belt 51 that moves (swings) between the printing position IP and the first retracted position FP. In other words, the transport belt 51 is provided in the printer 11 so as not to come into contact with the cap 71 and the cap moving mechanism 70 that do not cover the printing unit 18 when moving between the printing position IP and the first retracted position FP. Has been.

  The cap moving mechanism 70 moves the printing unit 18 to a position (hereinafter, referred to as “maintenance position”) out of the printing region in the width direction in order to execute the flushing operation. The cap 71 is moved below the printing unit 18 so as to cover the. The flushing is performed with the printing unit 18 covered with the cap 71. Further, in the state where the printing unit 18 is moved to the maintenance position for the execution of the flushing operation, the conveyor belt 51 keeps the conveyor belt 51 rotating in a circular shape, and the conveyor belt 51 keeps the second retracted position described later. Placed at SP. That is, the conveyance belt 51 is separated from the printing unit 18 to prevent ink leaking from the cap from adhering to the conveyance belt 51 during flushing.

The configuration of the belt moving unit 60 will be described with reference to FIG.
The conveyor belt 51 has a longitudinal direction in the width direction X similarly to the printing unit 18. A belt moving unit 60 is connected to both ends of the conveyor belt 51 in the width direction X. The belt moving unit 60 moves the conveyor belt 51 between the printing position IP, the second retracted position SP, and the first retracted position FP. That is, as the worm gear 65 meshing with the worm 66 fixed to the motor shaft of the motor M included in the belt moving unit 60 rotates, the rotary shaft 64 having the worm gear 65 fixed to one end thereof rotates. One end of the first link plate 63 is fixedly attached to the rotary shaft 64 at two positions apart from each other in the longitudinal direction (width direction X), and the second end is attached to the other end of the first link plate 63. One end of the link plate 62 is rotatably attached. The first link plate 63 and the second link plate 62 attached in this way constitute the link member 61.

  The drive roller 52 and the driven roller 53 that circulate the conveyor belt 51 are rotatably supported by the belt frame body 55 at both end portions in the belt width direction (here, the X direction) of the conveyor belt 51. Has been done. In the belt frame body 55, the portion that rotatably supports the roller shaft end of the driven roller 53 is the base portion 55a when the portion that rotatably supports the roller shaft end of the drive roller 52 is the base portion 55a. On the other hand, it is an expanding / contracting portion 55b that expands / contracts in a direction connecting the axis of the drive roller 52 and the axis of the driven roller 53. Then, in the present embodiment, the expansion / contraction portion 55b is urged by the urging member (not shown) provided on the belt frame body 55 in the direction of jumping out from the base portion 55a. As a result, the driven roller 53 supported by the expansion / contraction portion 55b is urged so that the distance between the driven roller 53 and the drive roller 52 becomes longer, and the conveyance roller 51 hung between the drive roller 52 and the driven roller 53 is urged. And a predetermined tension is applied. In this way, the transport belt 51 is stretched between the drive roller 52 and the driven roller 53.

  Further, the belt frame body 55 is formed with a concave portion 57 which is a substantially rectangular groove in the base portion 55a. On the other hand, a substantially columnar pin 67 is attached to the other end of the second link plate 62, and the pin 67 enters the recess 57 of the belt frame body 55 and is engaged therewith. Therefore, as indicated by a solid arrow CW in FIG. 3, the rotation shaft 64 rotates clockwise when viewed from the + X direction side by the drive of the motor M, and the rotation of the rotation shaft 64 causes the first link plate 63 and the first link plate 63 to rotate. When the second link plate 62 moves, the pin 67 attached to the second link plate 62 moves (swings) the belt frame body 55. In this way, the belt moving unit 60 moves the conveyor belt 51 to the printing position IP by moving the belt frame body 55. Further, as indicated by a dashed arrow CCW in FIG. 3, the rotation shaft 64 rotates counterclockwise when viewed from the + X direction by the driving of the motor M, and the rotation of the rotation shaft 64 causes the first link plate 63 and the first link plate 63 to rotate. When the second link plate 62 moves, the pin 67 attached to the second link plate 62 moves the belt frame body 55.

  By the movement of the belt frame body 55 by the belt moving unit 60, the conveyor belt 51 moves (swings) to the same first retracted position FP as in the state shown in FIG. In the present embodiment, the rotation of the motor M is converted into the rotation of the worm gear 65 that meshes with the worm 66 attached to its rotation shaft (motor shaft). Therefore, the rotating shaft 64 to which the worm gear 65 is attached rotates at a rotation angle smaller than the rotation speed of the motor M (rotation speed of the worm 66). In other words, the rotation of the motor M allows the rotation shaft 64 to rotate at a highly accurate rotation angle.

  In the present embodiment, the transport belt 51 can rotate not only in the state of being located at the printing position IP but also in the state of being located at the first retracted position FP or the second retracted position SP. It is provided.

  In the present embodiment, the printer 11 is provided with a single cleaning unit 90 having a cleaning member 91 that removes stains on the conveyor belt 51 and the supply drive roller 30a that constitutes the third supply roller pair 33. That is, the cleaning unit 90, in which a part of the cleaning member 91 is in contact with the peripheral surface of the supply drive roller 30a, can be reciprocated along the transport direction Y in accordance with the rotational driving of a motor (not shown) as a drive source. ing. Then, when the cleaning member 91 moves in the transport direction Y and comes into contact with the belt surface 51a of the transport belt 51, dirt such as ink attached to the belt surface 51a is wiped off for cleaning.

The cleaning unit 90 will be described with reference to FIG.
In the printer 11 of the present embodiment, a cleaning member for wiping and removing (cleaning) stains attached to the peripheral surface of the supply driving roller 30a and the belt surface 51a of the conveyor belt 51 that form the third supply roller pair 33. A cleaning unit 90 having a 91 is provided (see FIGS. 1 and 2).

  A cleaning member 91 formed of a belt-shaped member such as a woven cloth (web) is attached to a base frame 92 included in the cleaning unit 90 in a state of being wound in a roll shape on a round shaft-shaped roll core. In the present embodiment, the cleaning unit 90 has a roll core 94a on the unwinding side of the cleaning member 91 and a roll core 94b on the winding side, and both ends of each of the roll cores 94a, 94b rotate on the base frame 92. It is attached freely. Then, the cleaning member 91 is paid out from the roll core 94a on the unwinding side and wound on the roll core 94b on the winding side. The cleaning member 91 is wound around the first winding portion 95A to the fifth winding portion 95E in order from the roll core 94a side. The first winding portion 95A is arranged closest to the unwinding side roll core 94a in the moving direction of the cleaning member 91. The second winding portion 95B is arranged at the uppermost position. The third winding portion 95C is arranged closest to the conveyor belt 51 side. The fourth winding portion 95D is arranged between the third winding portion 95C and the fifth winding portion 95E. The fifth winding portion 95E is arranged on the roll core 94b side closest to the winding side in the moving direction of the cleaning member 91.

  The cleaning unit 90 also includes a power transmission mechanism (not shown) attached to the base frame 92. This power transmission mechanism is composed of, for example, a plurality of gears. Similarly, the rotational drive of a motor as a drive source (not shown) is transmitted to the roll core 94b on the winding side by the power transmission mechanism to rotate the roll core 94b. Let By the rotation of the roll core 94b on the winding side, the cleaning member 91 wound on the roll core 94a on the unwinding side is unwound, and a plurality of winding portions (books) rotatably attached to the base frame 92 are provided. (Five in the embodiment) 5A to 95E are moved while being hung on 95A to 95E, and are wound around the winding-side roll core 94b. That is, the cleaning member 91 is a long member whose length direction is a direction intersecting with the width direction X and is provided so as to be movable in the length direction.

  Here, the second winding portion 95B is supported by the base frame 92 by being biased by the spring toward the supply driving roller 30a at a position facing the supply driving roller 30a. That is, the portion of the cleaning member 91 that is wound around the second winding portion 95B provided at the tip of the extending portion 96 is in contact with the peripheral surface of the supply driving roller 30a. In other words, the portion of the cleaning member 91 that is wound around the second winding portion 95B provided at the tip of the extending portion 96 serves as a roller cleaning portion (first cleaning portion) 99 that cleans the supply drive roller 30a. Function.

  The third winding portion 95C is arranged so as to face the conveyor belt 51 located at the first retracted position FP. The cleaning unit 90 is configured such that the base frame 92 reciprocates (slides) along the transport direction Y by, for example, a drive source (not shown) such as an actuator. The cleaning member moving unit moves the cleaning unit 90 to the upstream side in the transport direction Y to move the cleaning member 91 wound around the third winding unit 95C from the transport belt 51 located at the first retracted position FP. It is located at a separated position. In the cleaning unit 90 located at the separated position, the cleaning member 91 wound around the second winding portion 95B is in contact with the peripheral surface of the supply drive roller 30a. In addition, the cleaning member moving unit moves the cleaning unit 90 to the downstream side in the transport direction Y to bring the cleaning member 91 wound around the third winding unit 95C into contact with the belt surface 51a of the transport belt 51. Located in. That is, the cleaning member 91 wound around the third winding portion 95C functions as the belt cleaning unit 100 (second cleaning unit) that cleans the conveyor belt 51. In the cleaning of the conveyor belt 51, the conveyor belt 51 moves to the first retracted position FP while the circuit is stopped, and the cleaning unit 90 moves to the contact position. Then, the transport belt 51 is rotated while the cleaning member 91 is in contact with the belt surface 51 a of the transport belt 51.

With reference to FIGS. 5 and 6, the medium separation unit 110 that separates the sheet 14 adsorbed on the conveyor belt 51 from the conveyor belt 51 will be described.
The medium separation unit 110 is arranged on the upstream end side of the discharge path 25 and on the downstream side of the conveyor belt 51. The medium separating unit 110 can be attached to the belt frame body 55, but in the present embodiment, it is not attached to the belt frame body 55 but to the upstream portion of the second conveying unit 26B on the downstream side of the conveying belt 51. That is, when the conveyor belt 51 moves to the second retracted position SP or the first retracted position FP, the conveyor belt 51 and the medium separating unit 110 are separated from each other. The medium separating unit 110 is horizontally movably attached to the second conveying unit 26B in order to adjust the pressure of the contact portion between the conveying belt 51 and the claw portion 125 of the separating claw 120.

  The medium separation unit 110 includes a plurality of separation claws 120 and a support member 130 that rotatably supports the plurality of separation claws 120. The separation claw 120 separates the sheet 14 from the conveyance belt 51 by bringing a claw portion 125 (see below) into contact with the surface of the conveyance belt 51 on which the sheet 14 is adsorbed. The medium separation unit 110 is configured to extend along the width direction X, and the plurality of separation claws 120 are arranged in a line along the width direction X. The spacing distance between the plurality of separation claws 120 is not set to a fixed distance but set appropriately. The surface of the separation claw 120 (particularly the first surface 125b) may be treated to be water repellent. This is because, in the example of the embodiment, double-sided printing may occur and the printing surface may contact the separation claw 120.

  As shown in FIG. 6, the separation claw 120 includes a support portion 121 that is rotatably supported on an axis along the width direction X of the support member 130, and a claw that extends from the support portion 121 and contacts the conveyor belt 51 ( Hereinafter, the first arm 122 having a "claw portion 125") and the second arm 123 extending from the support portion 121 in a direction different from the first arm 122 are provided. Specifically, the first arm 122 extends from the support portion 121 in a direction intersecting the rotation axis of the separation claw 120, and has a claw portion 125 at its tip.

  Further, the separation claw 120 is biased so that the claw portion 125 presses the conveyor belt 51. In the present embodiment, the coil spring 127 is attached to the hook 126 provided on the second arm 123, and the claw portion 125 is biased to press the transport belt 51. The separation claw 120 may be biased so that the claw 125 presses the conveyor belt 51 by attaching a torsion spring to the support 121 or by attaching a spring to the first arm 122.

  The support portion 121 of the separation claw 120 is located below the discharge path 25. The first arm 122 of the separation claw 120 extends toward the driven roller 53 of the transport belt 51 arranged at the printing position IP. The claw 125 at the tip of the first arm 122 contacts the portion where the conveyor belt 51 starts to curve downward in the conveying direction Y. The claw portion 125 has an abutting end 125a that abuts on the conveyor belt 51, a first surface 125b that faces upward when abutting on the conveyor belt 51, and a contact surface 125a that abuts on the conveyor belt 51. It has the 2nd surface 125c which confronts. The first surface 125b is arranged substantially horizontally when the contact end 125a contacts the conveyor belt 51. The second surface 125c is configured to be separated from the transport belt 51 when the contact end 125a is in contact with the transport belt 51.

  The force with which the claw portion 125 of the separation claw 120 pushes the conveyor belt 51 (hereinafter, referred to as “pressing force”) is determined by the lift of the claw portion 125 from the belt surface 51a when the conveyor belt 51 is rotated. Is set to be smaller than the thickness of. This is because the paper 14 cannot be separated from the transport belt 51 if the floating is excessive. More preferably, the pressing force with which the claw portion 125 of the separation claw 120 pushes the transport belt 51 is set so that the vibration of the claw portion 125 due to the collision when the transport belt 51 returns to the printing position IP is suppressed. . Specifically, when the transport belt 51 returns to the printing position IP, the transport belt 51 collides with the claw portion 125 of the separation claw 120, and the claw portion 125 separates from the transport belt 51. The movement direction of the claw portion 125 separated from the transport belt 51 is reversed by the force based on the coil spring 127, the claw portion 125 approaches the transport belt 51, and collides with the transport belt 51. Then, due to this collision, the claw portion 125 is repelled by the transport belt 51, and the claw portion 125 is separated from the transport belt 51. In this way, the pawl portion 125 vibrates based on the return of the transport belt 51. If the time until the vibration converges is long, it becomes impossible to separate the sheet 14 that enters the transport belt 51 from the upstream side in the transport direction Y next.

  Due to this, the magnitude of the pressing force is set so that the vibration of the claw portion 125 converges within a predetermined time. For example, the predetermined time is set as a time shorter than the time TA (see FIG. 10) from the time when the transport belt 51 returns to the printing position IP to the time when the paper 14 starts to enter the transport belt 51. These conditions (conditions for suppressing floating and conditions for suppressing vibration) are conditions that determine the lower limit of the pressing force with which the claw portion 125 of the separation claw 120 pushes the conveyor belt 51. On the other hand, the upper limit of the pressing force with which the claw portion 125 of the separation claw 120 pushes the conveyor belt 51 is determined by the abrasion of the conveyor belt 51 due to the friction between the claw portion 125 of the separation claw 120 and the conveyor belt 51. . That is, if the pressing force of the claw portion 125 of the separation claw 120 to press the conveyor belt 51 is excessive, the usage period is shortened due to damage due to abrasion of the conveyor belt 51. Therefore, the magnitude of the pressing force with which the claw portion 125 of the separation claw 120 pushes the conveyor belt 51 is set to a value that does not cause excessive abrasion of the conveyor belt 51.

An example of satisfying these conditions will be described below.
When the impact force applied to the pawl portion 125 when the conveyor belt 51 collides with the pawl portion 125 is 0.4 N, the pressing force with which the pawl portion 125 presses the conveyor belt 51 is about 0.07 N (for example, 0. It is set to 065N or more and 0.074N or less). Then, when the magnitude of the pressing force that pushes the conveyor belt 51 is set to 0.07 N, an example of the length of the first arm 122, the length of the second arm 123, and the force of the spring is as follows. . The distance LA from the rotation center of the separation claw 120 to the claw portion 125 is 28.5 mm, the distance LB from the rotation center to the spring action portion (load point PWP) is 8.25 mm, and the coil spring 127 causes the load point PWP. The magnitude of the force applied to is 0.24 N (see FIG. 6).

  The operation and action of the printer 11 during flushing will be described with reference to FIGS. 7 to 10. Note that, in FIG. 10, in the passing state of the sheet 14, the solid line indicates the period during which the sheet 14 passes the transport belt 51, and the broken line indicates the state of the missing sheet 14 (see later).

  The flushing is executed when a predetermined condition is satisfied during printing. For example, it is executed based on the fact that the amount of decrease in ink becomes larger than the predetermined amount. That is, flushing is executed when a predetermined condition is satisfied while the paper 14 is being continuously conveyed. As described above, in the flushing during printing, in the transport control of transporting the sheet 14 at a predetermined time interval, the sheet 14 is not transported once or a predetermined number of times at the flushing timing (the sheet 14 is not picked up). Is created. That is, one or a plurality of sheets 14 (see the broken line in FIG. 10) are formed in the group of the sheets 14 (solid line and broken line in FIG. 10) that are continuously transported in the transport path of the sheet 14. It should be noted that it is preferable that only one sheet is missing in order to prevent a decrease in print processing capability of the sheet. The conveyance speed of the paper is, for example, 23 inches / second (584.2 mm / second).

  The transport belt 51 is maintained at the printing position IP when the paper 14 passes through. Immediately after the sheet 14 immediately before the sheet has passed (time t1 in FIG. 10), the conveyor belt 51 rotates the belt unit 50 by the rotational driving of the motor M, as shown in FIG. 51 moves to the second retracted position SP in the orbiting state. This travel time is about 0.6 seconds. On the other hand, the printing unit 18 moves to the maintenance position, the cap moving mechanism 70 places the cap 71 under the printing unit 18, and the printing unit 18 is covered with the cap 71. Then, the flushing of the printing unit 18 is executed (see time t2 to time t3 in FIG. 10). When the flushing is completed, the cap moving mechanism 70 returns the cap 71 to the lower position, and at the same time, the belt unit 50 is rotated by the rotational driving of the motor M and the transport belt 51 moves toward the printing position IP (see FIG. 10). Time t4). This travel time is about 0.6 seconds. When the conveyor belt 51 reaches the printing position IP (time t5 in FIG. 10), the conveyor belt 51 collides with the separation claw 120 as shown in FIG. 8, so that the separation claw 120 collides with the separation claw 120 as shown in FIG. 9. It vibrates vertically. As for the vibration of the separation claw 120, the pressing force of the claw portion 125 is set so that the damping time is equal to or less than the predetermined time as described above. Therefore, after the transport belt 51 collides with the claw portion 125, the vibration of the claw portion 125 is quickly attenuated. After that, the sheet 14 immediately after the sheet is removed passes over the separation claw 120.

  As described above, the rotation operation of the transport belt 51, the series of flushing operations, and the converging operation of the claw portion 125 are performed from the time when the paper sheet 14 immediately before the paper sheet has passed through the transport belt 51 to the paper sheet 14 immediately after the paper sheet is missing. Is executed until the time when the sheet enters the conveyor belt 51. The vibration of the separation claw 120 causes a jam, but the vibration of the separation claw 120 quickly converges as described above, so that the jam is suppressed.

Hereinafter, the function and effect of the printer 11 as a printing device will be described.
(1) In the printer 11, the separation claw 120 is supported by the second transport unit 26B (a structure other than the first transport unit 26A) arranged on the downstream side of the transport belt 51 in the transport direction. The conveyor belt 51 is movably supported between the printing position IP (conveyance position) and the first retracted position FP (or the second retracted position SP). Further, when the conveyor belt 51 moves from the first retracted position FP (or the second retracted position SP) to the printing position IP, the conveyor belt 51 with respect to the direction from the support portion 121 of the separation pawl 120 to the pawl portion 125. The separation claw 120 approaches the separation claw 120 from the intersecting direction and contacts the separation claw 120.

  According to this configuration, when the conveyor belt 51 returns from the first retracted position FP (or the second retracted position SP) to the printing position IP, the conveyor belt 51 does not move toward the claw portion 125 of the separation claw 120 but is separated. The claw 120 moves so as to approach the separation claw 120 from a direction intersecting the direction from the support portion 121 to the claw portion 125 of the claw 120. For this reason, the claw portion 125 at the tip of the separation claw 120 is suppressed from being stuck in the conveyor belt 51, and damage to the conveyor belt 51 is suppressed.

  (2) When the printing unit 18 of the printer 11 is maintained (flushing in the present embodiment, cleaning of the transport belt 51), the transport belt 51 moves from the print position IP to the first retracted position FP (or the second retracted position SP). Move to. With this configuration, liquid such as ink that scatters during maintenance of the printing unit 18 is less likely to adhere to the transport belt 51. That is, the contamination of the conveyor belt 51 is suppressed. The conveyor belt 51 moves from the print position IP to the first retracted position FP (or the second retracted position SP) during the head cleaning as maintenance. In addition, each maintenance may be continuously performed at the same time, or may be performed at different time zones.

  (3) The separation claw 120 is supported by the structure (that is, the second transport unit 26B) located downstream of the transport belt 51 in the transport direction of the sheet 14. According to this configuration, for example, the transport belt 51 is rotated about the upstream drive roller 52 to move between the printing position IP (transport position) and the first retracted position FP (or the second retracted position SP). Even when the separation belt 120 is allowed to move, the separation claw 120 does not hinder the movement of the conveyor belt 51.

  (4) The force applied to the claw portion of the separation claw 120 when the transport belt 51 moves from the second retracted position SP to the printing position IP and contacts the separation claw 120 is 0.4 N or less. According to this configuration, the amplitude of the vibration of the claw portion caused by the collision of the conveyor belt 51 with the separation claw 120 becomes smaller than that in the case where the force is larger than 0.4 N, and the time for the vibration to converge. Becomes shorter. As a result, the sheet 14 is suppressed from being caught by the separation claw 120 as compared with the case where the vibration of the claw portion 125 of the separation claw 120 continues for a long time.

  (5) The separation claw 120 is biased so that the claw portion 125 at the tip of the first arm 122 presses the conveyor belt 51. According to this configuration, the claw portion 125 is prevented from separating from the transport belt 51 when the transport belt 51 circulates, and the sheet 14 is prevented from being separated by the separation claw 120.

  (6) The force (pressing force) by which the claw portion 125 of the separation claw 120 pushes the conveyor belt 51 is 0.065 N or more and 0.074 N or less, and the length of the first arm 122 is 28.5 mm. Is preferred. According to this configuration, the claw portion 125 of the separation claw 120 presses the conveyor belt 51 with an appropriate force (torque), so that the claw portion 125 is less lifted from the conveyor belt 51 and the conveyor belt 51 is worn. Will be suppressed.

  (7) The distance LB between the load point PWP of the second arm 123 and the rotation center of the support portion 121 is 8.25 mm, the distance LA between the claw portion 125 and the rotation center of the support portion 121 is 28.5 mm, The force applied to the load portion of the second arm 123 is 0.24N. According to this configuration, the force with which the claw portion 125 of the separation claw 120 presses the conveyor belt 51 is set to about 0.07N. Moreover, since the length of the second arm 123 is shorter than the length of the first arm 122 and the overall size of the separation claw 120 is compact, the member that supports the separation claw 120 can be made compact.

<Other embodiments>
In the present embodiment, the separation claw 120 is configured as a lever having the two arms 122 and 123 with the support portion in between, but the structure of the separation claw 120 is not limited to this. For example, the separation claw 120 has a support portion that serves as a center of rotation and an arm that extends from the support portion. A spring is attached to this arm so that the claw portion 125 of the separation claw 120 presses the conveyor belt 51. Energize the arm.

  In the embodiment, the conveyor belt 51 moves from the printing position IP to the first retracted position FP or the second retracted position SP by the rotation of the belt unit 50, but the manner of movement of the conveyor belt 51 is not limited to this. As shown in FIG. 11, the conveyor belt 51 may be configured to move in parallel (vertical direction or diagonal direction). Further, the movement path of the conveyor belt 51 may be configured to follow an arc or a curve close to it.

  11 ... Printer (printing device), 14 ... Paper (medium), 18 ... Printing unit, 26A ... First transport unit, 26B ... Second transport unit, 51 ... Transport belt, 110 ... Medium separating unit, 120 ... Separation claw, 121 ... Supporting part, 122 ... First arm, 123 ... Second arm, 125 ... Claw part, IP ... Printing position (conveying position), FP ... First retracted position, SP ... Second retracted position (retracted position).

Claims (8)

A first transport unit having a transport belt that attracts and transports a medium, a printing unit that prints on the medium attracted on the transport belt, and a surface of the transport belt that attracts the medium. contact touch and a separation claw for separating the medium from the transport belt, the second transport for conveying the medium separated by the separation claw on the downstream side in the transport direction of the medium than the first conveyor to comprises a part, the,
The separation claw has a claw portion that extends in the transport direction of the medium and contacts the transport belt,
The conveyor belt is retracted retracted pre SL medium at a position in contact with the claw portion and the transport position for transporting the second conveyance unit, from the transport position to a position apart from the pawl portion position and is movably supported between said when from the retracted position to move to the transport position, characterized in that the direction intersecting the direction in which the front tight portion extends abuts close to the claw portion And printing device. The printing apparatus according to claim 1, wherein the transport belt moves from the transport position to the retracted position when the printing unit is maintained. The separation pawl, the printing apparatus according to claim 1 or claim 2 wherein the than the conveyor belt is supported by the structure body you located downstream in the transport direction of the medium. Force the conveyor belt is applied to the tight unit before when you contact with the claw portion by moving the transport position from the retracted position to any one of claims 1 to 3 or less 0.4N The printing device described. The separation claw has a support portion that is rotatably supported, a first arm that having a the claw portion at the tip extends in a direction intersecting the rotation axis of the separation claw from the support portion, said support portion A second arm extending in a direction different from the first arm from the first arm, and the claw portion at the tip of the first arm is biased to press the conveyor belt. The printing device according to any one of claims. Before force tight portion presses the conveyor belt is less 0.074N than 0.065 N, the length of the first arm, the printing apparatus according to claim 5 is 28.5 mm. The distance between the load portion of the second arm and the rotation center of the support portion is 8.25 mm, the distance between the claw portion and the rotation center of the support portion is 28.5 mm, and the load of the second arm is The printing device according to claim 6, wherein the force applied to the location is 0.24N.   The conveyor belt is configured by being stretched around a driving roller and a driven roller,
  Of the drive roller and the driven roller, the roller on the side away from the claw portion is swung to move the position between the transport position and the retracted position.
  The printing device according to any one of claims 1 to 7.

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