JP2011057303A - Medium feeding device and recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medium feeding device which stabilizes the posture of a medium to be fed with respect to the feeding direction. <P>SOLUTION: In the medium feeding device (3), a plurality of feed roller pairs consist of feed driving rollers (50a-50e) and feed driven rollers (51a-51e), the feed driving rollers are driven in the forward direction and a medium to be fed is fed to the downstream side in the feeding direction in a first state in which the feed driving rollers and the feed driven rollers are brought close to each other, and when the posture at the fore end which is the downstream end in the feeding direction of the medium is copied in the direction (X) of the line (L) formed by circumscribed parts of the conveying roller pairs, the feed roller pair (for example, 96b for A3 (sign P6) size) in the first state out of the plurality of feed roller pairs are selected according to the size of the medium to be fed, and other feed roller pairs (96a, 96c-96e) are in a second state in which the feed driving rollers and the feed driven rollers are separated from each other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention has a feed driving roller that is driven by power and a feed driven roller that is driven to rotate, a plurality of feed roller pairs that are arranged in the width direction of the medium to be fed and feed the medium to be fed downstream in the feed direction. The feed roller pair is disposed downstream of the feed roller pair in the feed direction and has a transport drive roller that is driven by power and a follower driven roller that is driven to rotate. The present invention relates to a medium feeding device including a pair of conveying rollers for conveying to a medium and a medium guide path section for guiding a medium to be fed from the pair of feeding rollers to the pair of conveying rollers, and a recording apparatus including the medium feeding device.
In the present application, the recording apparatus includes types such as an ink jet printer, a wire dot printer, a laser printer, a line printer, a copying machine, and a facsimile.

  Conventionally, as shown in Patent Document 1, the recording apparatus includes a paper feeding device that feeds paper to the recording unit. The paper feeding device includes a paper feeding roller, a pair of registration rollers, and a guide. Among these, the paper feed roller is provided so that the paper can be fed to the downstream side in the feed direction. The registration roller pair is provided on the downstream side in the feed direction from the paper feed roller, and has a drive roller and a driven roller. Accordingly, the sheet can be further fed downstream in the feeding direction. Still further, the guide is provided so as to guide the paper from the paper feed roller to the registration roller pair.

Further, when the registration roller pair feeds the paper to the downstream side in the feeding direction, so-called skew removal is performed to correct the inclined posture of the paper with respect to the feeding direction.
Here, “skew removal” means correcting the tilted posture of the medium to be fed with respect to the feeding direction. In particular, this means correcting the tilted posture of the leading end, which is the downstream end of the sheet feeding direction with respect to the nip line. Further, the “nip line” refers to a line formed by a circumscribed portion of the roller pair. That is, it is a line formed by a pinching portion in the roller pair.
Specifically, the leading end, which is the downstream end in the sheet feeding direction, is pressed against a portion that circumscribes the registration roller pair. As a result, the posture of the leading edge of the paper is made to follow the nip line of the registration roller pair.

JP-A-8-157107

Here, it is conceivable that the guide has a side-curved portion. In this case, in order to stabilize the posture with respect to the paper feeding direction, it is necessary to apply a feeding force to the paper substantially evenly in the paper width direction. For this purpose, it is conceivable to arrange a plurality of the paper feed rollers in the width direction.
However, if a plurality of paper feed rollers are simply arranged, they contact the paper at a plurality of locations in the width direction. Therefore, when skew removal is performed, only the posture of the front edge of the paper follows the nip line. That is, the rear end side of the sheet remains inclined. At this time, there is still a difference in the amount of bending between the sheet feeding roller and the registration roller pair in the left and right direction in the width direction of the sheet. Here, the bending of the sheet acts to push the leading end side of the sheet to the downstream side in the feeding direction. The magnitude of the acting force varies depending on the difference in the amount of bending between the left and right sides of the sheet.

Therefore, when the sheet is further fed to the downstream side in the feeding direction by the registration roller pair in the above state, the feeding amount on the left and right sides of the sheet is different due to the difference in the deflection amount, and the whole sheet may be inclined with respect to the feeding direction. . This is a so-called cumulative skew.
Further, when a space for sufficiently bending the paper cannot be secured between the paper feed roller and the registration roller pair, there is a possibility that sufficient skew removal cannot be executed.

  The present invention has been made in view of such a situation, and its problem is to provide a medium feeding device that takes into account the stabilization of the posture of the medium to be fed in the feeding direction, and a recording apparatus including the medium feeding device. Is to provide.

  In order to achieve the above object, the medium feeding device according to the first aspect of the present invention includes a feed driving roller that is driven by power and a feed driven roller that is driven to rotate, and a plurality of media feeding devices are arranged in the width direction of the medium to be fed. A feed roller pair that feeds the medium to be sent downstream in the feed direction, a feed drive roller that is arranged on the downstream side in the feed direction from the feed roller pair, and that is driven by power, and a follower roller that is driven to rotate. A pair of transport rollers for transporting the medium to be fed sent by the pair of feed rollers to the downstream side in the feed direction, a medium guide path section for guiding the medium to be fed from the pair of feed rollers to the pair of transport rollers, and the plurality The feed driving roller and the feed driven roller of the pair of feed rollers are relatively moved toward and away from each other, and the feed drive roller and the feed driven roller Switching means for switching between a first state in which the two are close to each other and a second state in which they are separated from each other, wherein the medium feeding device removes the medium to be fed from the plurality of pairs of feeding rollers. When sending to a pair of transport rollers, the plurality of feed roller pairs are set to the first state, the feed drive roller is driven to rotate forward to feed the medium to be fed to the downstream side in the feed direction, and is the downstream end in the feed direction of the medium to be fed. When the posture of the tip is copied in a line direction formed by a circumscribed portion of the transport roller pair, a feed roller pair to be in the first state is selected from the plurality of feed roller pairs according to the size of the medium to be fed And it is the structure which makes another feed roller pair the said 2nd state.

  According to the first aspect of the present invention, the so-called skew removal operation in which the posture of the tip of the medium to be fed is made to follow the linear direction of the pair of transport rollers is generated on the rear end side of the medium to be fed. The posture on the rear end side can be made to easily follow the posture on the front end side by a force for rotating the rear end side. Specifically, when the posture of the tip of the medium to be fed is copied in the linear direction, a part of the feeding roller pairs is selected to be in the first state, and the other feeding roller pairs are in the second state. Thereby, the contact point which the said feed roller pair clamps the back end side of a to-be-feeded medium can be decreased.

Here, when one feed roller pair is selected from the plurality of feed roller pairs, the contact point can be set to one point. In this case, the rear end side of the medium to be fed can be easily rotated using the one point as a fulcrum as compared with the case where there are a plurality of contact points.
Further, since the feed roller pair to be in the first state is selected according to the size of the medium to be fed, the rear end side of the medium to be fed can be easily rotated in each size as well. The rear posture can be made to follow the tip posture.

  Furthermore, since the posture of the rear end side of the medium to be fed can be made to follow the posture of the leading end, the difference between the left and right deflection amounts in the width direction can be eliminated. Then, it is possible to prevent a so-called cumulative skew from occurring due to the difference between the left and right deflection amounts during the subsequent conveyance. That is, by removing the difference in the force by which the medium to be fed is pushed downstream in the feeding direction due to the difference between the left and right bending amounts, the posture of the medium to be fed can be stabilized during the conveyance.

  Further, there may be a case where a sufficient space for bending the medium to be fed cannot be secured between the pair of feed rollers and the pair of transport rollers. In such a case, when one end side in the width direction cannot be bent any more, the one end side acts so that the rear end side of the medium to be fed is pushed upstream in the feed direction. At this time, the rear end side of the medium to be fed can be easily rotated with the one point as a fulcrum. That is, even when a space for deflecting the medium to be fed cannot be secured sufficiently, a so-called skew removal capability for removing the inclination of the medium to be fed with respect to the feeding direction can be secured.

In particular, when the stiffness of the medium to be fed is relatively strong, the medium to be fed tends to be difficult to bend.
Here, “the stiffness of the medium to be fed” refers to the elasticity and rigidity of the medium to be fed.
In such a case, when the posture of the front end is made to follow the linear direction, force can be efficiently transmitted to the rear end side due to the rigidity of the medium to be fed. As a result, the trailing end side of the medium to be fed can be rotated with the one point as a fulcrum, and the posture of the trailing end can be made to follow the posture of the leading end.

Note that the skew removal operation may be a so-called “biting and discharging method” or “abutting method”.
Here, in the “biting discharge method”, the transport roller pair once clamps the leading end of the medium to be transported, and the transport roller pair is reversed to reversely feed the front end side of the transported medium upstream in the feed direction. Then, between the feed roller pair and the transport roller pair, a method of deflecting the medium to be fed and pressing the tip of the medium to be fed against the nip line of the pair of transport rollers to follow the posture of the tip to the nip line. Say. In other words, once the leading edge of the medium to be fed is bitten by the pair of transport rollers, the leading medium side is deflected by discharging the leading edge of the medium to be fed upstream in the feeding direction so that the posture of the leading edge follows the nip line. This method.

  On the other hand, the “abutment method” refers to a nip line between a pair of conveying rollers in a state in which the tip of the medium to be fed is stopped or reversely driven by feeding the medium to the downstream side in the feeding direction by the pair of feeding rollers. This is a method in which the posture of the tip is made to follow the nip line by pressing against the nip line. That is, it refers to a system in which the tip of the medium to be fed is brought into contact with a pair of conveying rollers so that the posture of the tip follows the nip line. Note that the medium to be fed may be bent to follow the nip line between the pair of feed rollers and the pair of transport rollers, or the position of the tip may be copied to the nip line without bending. Good.

  According to a second aspect of the present invention, in the first aspect, the switching means includes a rotatable cam shaft, a plurality of cam portions provided on the cam shaft, and the plurality of cam portions. A plurality of cam follower portions that are provided on at least one side of the feed driving roller and the feed driven roller of the plurality of feed roller pairs and respectively engage with the plurality of cam portions, and the cam follower portion is displaced Accordingly, the first state and the second state are switched.

  According to the 2nd mode of the present invention, in addition to the same operation effect as the 1st mode, by rotating the one cam shaft, the 1st state and the above-mentioned about each of a plurality of above-mentioned feed roller pairs The second state can be switched. That is, the switching means can be configured easily. Specifically, the shape of at least a part of the plurality of cam portions is different from the shape of the other cam portions. Then, according to the size of the medium to be fed, one feeding roller pair can be selected from the plurality of feeding roller pairs to be in the first state, and the other feeding roller pairs can be in the second state.

  According to a third aspect of the present invention, in the first or second aspect, when the posture of the leading end of the medium to be fed is copied in the linear direction, the medium feeding device includes the plurality of feeding roller pairs, The feed roller pair closest to the center in the width direction of the medium to be fed is selected as the feed roller pair that is in the first state, and the other feed roller pair is in the second state.

According to the third aspect of the present invention, in addition to the same effects as those of the first or second aspect, only the pair of feed rollers closest to the center in the width direction of the medium to be fed are set in the first state during skew removal. And Therefore, when a force for rotating the rear end side is generated on the rear end side of the medium to be fed, the rear end side of the medium to be fed can be rotated about the pair of feed rollers closest to the center in the width direction.
For example, there may be a case where the medium to be fed is bent between the pair of feed rollers and the pair of transport rollers, and there is a difference in the amount of deflection on the left and right in the width direction.

  In such a case, the force to return to the original shape in the bending on the side with the large amount of bending on the left and right acts as the rotating force. Then, the rear end side can be rotated with the pair of feed rollers closest to the center in the width direction as a fulcrum, and the posture of the rear end side of the medium to be fed can easily follow the front end side. If the vicinity of the side end on the side where the amount of bending is large is used as a fulcrum, the force to return is not likely to act as the rotating force, and the posture on the rear end side may not follow the front end side. Compared to such a case, the posture on the rear end side can be easily followed to the front end side.

  Further, even when the medium to be fed is not bent, when the leading edge of the medium to be fed is abutted against the circumscribed portion of the pair of conveying rollers, the timing of abutting on the left and right in the width direction may be slightly different. is there. In such a case, a force for rotating the rear end side is generated due to the difference in timing. Specifically, a pressing force is generated on the upstream side in the feed direction on the side that abuts in the width direction.

  Then, a force for rotating the rear end side of the medium to be fed is generated with the pair of feeding rollers as a fulcrum. At this time, since the fulcrum is in the vicinity of the center in the width direction, the posture of the rear end side of the medium to be fed can be easily followed to the front end side. If the vicinity of the side end on the side in the width direction is the fulcrum, the pushing force to the upstream side in the feed direction is unlikely to act as the rotating force, and the posture on the rear end side cannot be made to follow the front end side. There is a fear. Compared to such a case, the posture on the rear end side can be easily followed to the front end side.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the medium guide path part has a side-curved section.
According to the fourth aspect of the present invention, in addition to the same function and effect as any one of the first to third aspects, when the side-view curved section is included, the curved section is included. The frictional resistance generated between the medium to be fed and the medium guide path is greater than that in the case where there is no medium. Therefore, it is necessary to increase the force for feeding the medium to be fed from the feed roller pair to the transport roller pair. Therefore, a plurality of the feed roller pairs are arranged in the width direction, and a sufficient feed force can be applied to the medium to be fed. In such a case, the configuration of selecting and switching by the switching means is particularly effective.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, when the posture of the tip of the medium to be fed is made to follow the linear direction of the pair of transport rollers, By rotating and driving, the tip of the medium to be fed is sandwiched between the pair of transport rollers, and the transport drive roller is driven in reverse to bend the medium to be fed between the pair of transport rollers and the pair of transport rollers in the feed direction. Accordingly, when the leading end of the medium to be fed is made to follow the linear direction of the pair of transport rollers, the transport driving roller is driven to rotate forward, and the leading end side of the medium to be transported is sandwiched between the pair of transport rollers, The feed roller pair to be in the first state is selected and the other feed roller pair is in the second state.

  According to the fifth aspect of the present invention, in addition to the same function and effect as in any one of the first to fourth aspects, the tip of the medium to be fed once held by the pair of transport rollers is reversed upstream in the feed direction. To send. Then, skewing is performed by a so-called biting and sticking-out method in which the medium to be fed is bent on the upstream side of the pair of conveying rollers to cause the leading edge to follow the linear direction. In such a case, when the leading end is initially inclined with respect to the linear direction, a difference in the amount of bending between the left and right sides is always generated, and the rotating force is generated on the rear end side of the medium to be fed, which is effective.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects, after the front end of the medium to be fed is made to follow the linear direction of the pair of transport rollers, the transport drive roller and the feed drive After the roller is driven forward, the tip of the medium to be fed is sandwiched between the pair of transport rollers, the feed roller pair to be in the first state is selected, and the other feed roller pair is in the second state The medium feeding device sets at least the feeding roller pair facing the medium to be fed among the plurality of feeding roller pairs to the second state, and drives the feeding driving roller to rotate forward so that the medium to be fed is the medium guide path section. It is the structure which is made to imitate.

  According to the sixth aspect of the present invention, in addition to the same operational effects as in any one of the first to fifth aspects, after the skew removal is completed, at least the feeding roller pair facing the medium to be fed is Two states are set, and the feed drive roller is driven to rotate forward so that the medium to be fed follows the medium guide path. At this time, since the feed roller pair is in the second state, an appropriate feed force can be applied while easily generating a slip between the feed drive roller and the medium to be fed. Therefore, the medium to be fed can be bent appropriately within the area guided by the medium guide path.

  As a result, the amount of deflection of the medium to be fed can be made substantially uniform in the width direction, and the difference in the amount of deflection on both sides in the width direction of the medium to be fed can be more reliably removed. In addition, it is possible to more reliably prevent the so-called cumulative skew from occurring due to the difference between the left and right deflection amounts during the subsequent conveyance. That is, by removing the difference in the force by which the medium to be pushed is pushed downstream in the feeding direction due to the difference between the left and right bending amounts, the posture of the medium to be fed with respect to the feeding direction can be further stabilized during conveyance.

Further, in this aspect, the feeding medium is moved away from the feeding driving roller by driving the feeding driving roller in the normal direction.
Here, if the feed drive roller is reversely driven, the fed medium behaves so as to be wound around the feed drive roller.
Therefore, in this aspect, it is possible to reduce the rotational load of the feed drive roller as compared with the case where the feed drive roller is reversely driven.

A recording apparatus according to a seventh aspect of the present invention includes a medium feeding unit that sends a recording medium downstream in the feeding direction, a recording unit that records the recording medium sent by the medium feeding unit by a recording head, The medium feeding means includes the medium feeding device according to any one of the first to sixth aspects, and the recording medium is the medium to be fed. And
According to a seventh aspect of the present invention, the medium feeding means includes the medium feeding device according to any one of the first to sixth aspects. Therefore, in the recording apparatus, it is possible to obtain the same operational effects as in any one of the first to sixth aspects.

FIG. 4 is a side view illustrating an operation during pickup in the printer according to the invention. FIG. 3 is a side view showing an operation during bank separation in the printer according to the present invention. FIG. 4 is a side view showing an operation of retard separation inside the printer according to the invention. FIG. 6 is a side view showing an operation after retard separation in the printer according to the invention. FIG. 6 is a side view showing an operation after retard separation in the printer according to the invention. The perspective view which shows the feed roller pair and switching means which concern on this invention. The side view which shows the initial biting state in the case of the skew removal which concerns on this invention. The side view which shows the state of each roller of the 2nd assist roller in FIG. The side view which shows the discharge state in the case of the skew removal which concerns on this invention. (A) (B) is a top view which shows the operation | movement concept in case of paper size A4 and A3. (A) (B) is a side view which shows the state of the 2nd assist roller in FIG. (A) (B) is a top view which shows the operation | movement concept in the case of paper size A2. (A) (B) is a side view which shows the state of the 2nd assist roller in FIG. The side view which shows the cueing state in the case of skew removal which concerns on this invention. The side view which shows the normal rotation operation | movement after the skew removal which concerns on this invention. The side view which shows a mode that the subsequent paper is picked up in this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side view showing an operation at the time of pickup in an ink jet printer (hereinafter referred to as “printer”) 1 as an example of a “recording apparatus” or a “liquid ejecting apparatus”.
Here, the liquid ejecting apparatus refers to an ink jet recording apparatus, a copying machine, a facsimile, or the like that performs recording on a recording material by ejecting ink from a recording head as a liquid ejecting head to a recording material such as recording paper. In addition to the recording apparatus, instead of ink, a liquid corresponding to a specific application is ejected from the liquid ejecting head corresponding to the recording head to the ejected material corresponding to the recording material, and the liquid is ejected to the ejected material. Used to include the device to be attached.

  Further, as the liquid ejecting head, in addition to the recording head described above, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an electrode material used for forming an electrode such as an organic EL display or a surface emitting display (FED). (Conductive paste) A jet head, a bio-organic matter jet head used for biochip manufacturing, a sample jet head for jetting a sample as a precision pipette, and the like.

  As shown in FIG. 1, the printer 1 includes a feeding unit 3 as a feeding device that feeds paper P, a recording unit 80, and a discharge unit (not shown). Among these, the feeding unit 3 includes a feeding unit 10 and a conveying unit 70. The feeding unit 10 includes a pickup unit 20, a preliminary separation unit 30, and a main separation unit 40. The pickup unit 20 is provided so that the paper P placed on the cassette unit 14 can be picked up and sent downstream in the feed direction.

  Specifically, it includes a pickup roller 21 that is driven by the power of a feeding motor 91 that is an example of a drive source, and an arm portion 22 that holds the pickup roller 21 and swings around an arm shaft 23 as a fulcrum. The pickup roller 21 is biased in a direction approaching the paper P by a biasing means (not shown). Further, the arm 22 is swung by a pickup retracting means (not shown) so that the pickup roller 21 can be moved away from the paper P on which the pickup roller 21 is placed. This is a so-called pickup release operation.

Further, the preliminary separation unit 30 includes a bank separation unit 31 that performs so-called bank separation. The operation will be described later.
Furthermore, the main separation unit 40 is provided on the downstream side in the feed direction of the preliminary separation unit 30. The separation unit 40 includes a so-called retard roller 41 that is rotated by a predetermined load. The retard roller 41 is provided so as to make a pair with the intermediate drive roller 50 driven by the power of the feeding motor 91. The retard roller 41 is provided to be movable toward and away from the intermediate drive roller 50 by the swing mechanism 43. Specifically, the swing mechanism 43 is configured to hold the retard roller 41 by a retard holder (not shown) and swing around a swing shaft (not shown).

  One end of the urging spring (not shown) is engaged with the base portion 2, and the other end is engaged with the free end side of the retard holder (not shown). Therefore, the retard roller 41 can be urged toward the intermediate drive roller 50. The swing mechanism 43 is a cam portion 45 that is driven by the power of the separation motor 92 as means for moving the retard roller 41 away from the intermediate drive roller 50 against the biasing force of a biasing spring (not shown). have. The cam portion 45 is engaged with a convex portion (not shown) of a retard holder (not shown) to form a groove cam mechanism, and the retard roller 41 is moved with respect to the intermediate drive roller 50 via the retard holder (not shown). It is provided so that it can be moved apart.

Further, a first assist roller 48 that is driven to rotate is provided between the bank separation unit 31 and the retard roller 41. The first assist roller 48 is provided so that the leading edge of the paper P that has passed through the bank separation unit 31 can be smoothly guided to the nip point N between the retard roller 41 and the intermediate drive roller 50.
Furthermore, on the downstream side in the feed direction from the nip point N between the retard roller 41 and the intermediate drive roller 50, paper front end regulating ribs 60, 60 described later are provided.

Further, on the downstream side in the feed direction, a second assist roller 51 that is rotatably held by the base portion 2 and circumscribes the intermediate drive roller 50 is provided. The second assist roller 51 is configured to form a feed roller pair 96 together with the intermediate drive roller 50. Further, a third assist roller 52 is rotatably provided on the downstream side in the feed direction.
Here, the feeding path of the paper P is formed in a U-shaped side view from the pickup unit 20 to the conveyance unit 70. Specifically, a U-shaped outer sheet guide unit 11 that guides the sheet P from the outside of the U-shape, an inner sheet guide unit 12 that guides the sheet P from the inside, a bank separation unit 31, and an entrainment prevention unit 13 that will be described later. A U-shaped feed path is configured by.

Accordingly, the first assist roller 48 to the third assist roller 52 can reduce the frictional resistance generated between the paper P and the U-shaped outer paper guide portion 11 of the base portion 2. Accordingly, it is possible to smoothly feed the paper P to the transport unit 70 on the downstream side in the feeding direction.
In addition, the intermediate drive roller 50 (50a-50e) and the 2nd assist roller 51 (51a-51e) which comprise the feed roller pair 96 are provided with two or more in the width direction X so that it may mention later (refer FIG. 6). This is because a sufficient feeding force is applied to the paper P in the side-view U-shaped path to reliably feed the paper P downstream in the feeding direction.

  The transport unit 70 includes a transport roller pair 71 that transports the paper P. The transport roller pair 71 includes a transport drive roller 72 that is driven by the power of the transport motor 94 and a transport driven roller 73 that is driven to rotate. Among these, the conveyance driven roller 73 is rotatably held by a driven roller holder 74.

  Further, the driven roller holder 74 presses the transport driven roller 73 against the transport driving roller 72 by an urging means (not shown).

  Furthermore, in the feed direction Y, a paper detector 75 that detects the presence or absence of the paper P is provided in the vicinity of the upstream side of the transport roller pair 71. Specifically, the paper detector 75 includes a swingable paper detection lever 77 and a sensor unit 76. Then, one end of the paper detection lever 77 is swung by coming into contact with the paper P, and the other end of the paper detection lever 77 is separated from a light emitting unit and a light receiving unit (not shown) of the sensor unit 76 to be turned on. It is comprised so that it may become.

Further, the transport unit 70 is provided so that the paper P can be transported to the recording unit 80 provided on the downstream side in the feed direction.
The recording unit 80 further includes a recording head 82 that performs recording by ejecting ink onto the paper P, and a medium support unit 81 that faces the recording head 82 and supports the paper P from below.
Thereafter, the recorded paper P is discharged to a discharge tray (not shown) on the front surface of the printer 1 by a discharge roller of a discharge unit (not shown).

Next, a more detailed paper feeding operation will be described.
As shown in FIG. 1, when picking up the uppermost sheet P1 with respect to the pickup roller 21 placed on the cassette unit 14, the control unit 90 swings the arm unit 22 to move the pickup roller 21 to the uppermost sheet. Contact with P1. Then, by driving the arm motor 93, the pickup roller 21 is rotated clockwise in the drawing.

  At this time, the pickup roller 21 is urged in a direction approaching the paper P by an urging means (not shown). Accordingly, a frictional force is generated between the pickup roller 21 and the uppermost sheet P1, and a feeding force that is a force fed downstream in the feeding direction can be generated. Then, the uppermost sheet P1 starts to move downstream in the feeding direction by the feeding force. That is, it is picked up and sent downstream.

Note that the friction coefficient μ1 between the pickup roller 21 and the uppermost sheet P1, the friction coefficient μ2 between the sheet P and the sheet P, and the pad portion 15 provided at a position facing the pickup roller 21 on the base unit side. When the friction coefficient μ3 between the paper and the paper P is set, the relationship of friction coefficient μ1> friction coefficient μ3> friction coefficient μ2 is established. Accordingly, it is possible to reduce the so-called double feed risk in which several sheets of paper P are fed in an overlapping manner.
Further, when picked up, the retard roller 41 is close to the intermediate drive roller 50.

FIG. 2 is a side view showing the operation at the time of bank separation inside the printer according to the present invention.
As shown in FIG. 2, the paper P picked up by the pickup roller 21 is sent downstream in the feed direction. Then, the fed paper P enters the bank separation unit 31 as the preliminary separation unit 30.

Here, the feeding force is also applied to the succeeding and subsequent sheets P2 by the friction coefficient μ2 between the uppermost sheet P1 and the succeeding and subsequent sheets P2 with respect to the pickup roller 21 and the urging force that urges the pickup roller 21. May occur.
In such a case, not only the uppermost sheet P1 but also the subsequent sheet P2 is fed to the downstream side in the feeding direction by the pickup roller 21.

  Therefore, in order to separate the second and subsequent sheets P2 that have been multi-fed from the uppermost sheet P1, the sheet P is caused to enter the bank separation unit 31 provided at an angle at which the posture of the leading end of the sheet P is displaced. Then, by applying the leading edge of the paper P to the bank separation unit 31, a trigger for stopping the subsequent paper P <b> 2 is created. Furthermore, a gap can be provided between the uppermost sheet P1 and the subsequent sheet P2. Therefore, the next and subsequent sheets P2 that are double-fed can be separated from the uppermost sheet P1.

FIG. 3 is a side view showing the operation of retard separation inside the printer according to the present invention.
As shown in FIG. 3, the paper P separated by the bank separation unit 31 is further fed downstream in the feeding direction by the pickup roller 21. Then, the paper P is sent to a nip point N where the retard roller 41 which is the main separation unit 40 and the intermediate drive roller 50 are circumscribed.
In the present embodiment, since the preliminary separation unit 30 is merely a preliminary separation unit, it is assumed that several sheets P may be double-fed to the main separation unit 40. Hereinafter, description will be made on the assumption that several sheets of paper P are double-fed.

When the multi-feed paper P is sent to the nip point N, only the uppermost paper P 1 is in direct contact with the intermediate drive roller 50 with respect to the intermediate drive roller 50. Further, the leading edge of the paper P2 after the next is in contact with the retard roller 41 with a predetermined load for rotation.
Here, the friction coefficient μ4 between the intermediate drive roller 50 and the uppermost sheet P1, the friction coefficient μ2 between the sheet P and the sheet P, and the friction coefficient μ5 between the retard roller 41 and the sheet P are set. , Friction coefficient μ4> friction coefficient μ2, and friction coefficient μ5> friction coefficient μ2.

Accordingly, the feeding force acting on the uppermost sheet P1 can be made larger than the feeding force acting on the subsequent sheet P2.
Here, the load of the retard roller 41 is configured to be larger than the feeding force acting on the succeeding and subsequent sheets P2.
Accordingly, by rotating the intermediate drive roller 50 in the clockwise direction in the drawing, only the uppermost sheet P1 can be sent downstream in the feed direction.

  More specifically, the leading edge of the succeeding sheet P2 is held at the nip point N by the load of the retard roller 41, and slip occurs between the uppermost sheet P1 and the next sheet P2. Can do. Accordingly, the uppermost sheet P1 can be separated from the subsequent sheet P2 and sent downstream in the feed direction. The leading end of the uppermost sheet P1 passes through the second assist roller 51 and reaches the third assist roller 52 while being guided by the U-shaped outer sheet guide unit 11 and the inner sheet guide unit 12.

FIG. 4 is a side view showing the operation after the retard separation in the printer according to the present invention.
As shown in FIG. 4, when the uppermost sheet P1 is further fed to the downstream side in the feeding direction with respect to the intermediate drive roller 50, the leading edge of the uppermost sheet P1 is detected by the sheet detector 75. Specifically, the leading end of the uppermost sheet P1 comes into contact with one end of the sheet detection lever 77, and the sheet detection lever 77 is swung. At this time, since the other end of the paper detection lever 77 is disengaged from between the light emitting part and the light receiving part of the sensor unit 76, the paper detector 75 is turned on.

Using this as a trigger, the control unit 90 moves the retard roller 41 away from the intermediate drive roller 50. Specifically, the cam 45 is rotated by the separation motor 92 and the retard holder (not shown) is retracted from the intermediate drive roller 50 against the biasing force of the biasing spring (not shown). Swing in the direction.
Further, the control unit 90 drives the arm motor 93 to swing the arm unit 22 around the arm shaft 23 in the direction in which the pickup roller 21 is retracted from the paper P placed on the cassette unit 14.

  The timing for starting the separation movement of the retard roller 41 may be when the intermediate drive roller 50 and the pickup roller 21 reach a predetermined rotation amount.

When the retard roller 41 moves away, the uppermost sheet P1 is fed by the intermediate drive roller 50 and the second assist roller 51.
Further, when the pickup roller 21 moves away, the feeding force does not directly act on the subsequent paper P2 from the intermediate drive roller 50 and the pickup roller 21. Therefore, the next and subsequent sheets P2 whose leading ends are held by the retard roller 41 try to return to the cassette unit 14 by their own weight.

However, the trailing edge of the preceding sheet P1, which is the uppermost sheet fed by the intermediate drive roller 50, and the leading edge of the succeeding sheet P2, which is the succeeding and subsequent sheets whose leading edge is held by the retard roller 41, Touch. Accordingly, the feeding force acts indirectly on the succeeding paper P2.
Therefore, convex paper leading edge regulating ribs 60 and 60 are provided on the downstream side in the feed direction from the nip point N between the intermediate drive roller 50 and the retard roller 41 in the U-shaped outer paper guide portion 11. Further, the paper leading edge regulating ribs 60 and 60 are provided in the vicinity of both sides of the retard roller 41 in the width direction X of the paper P.

Since the feed path is bent in a U-shape, when the retard roller 41 moves away, the leading edge of the succeeding paper P2, which is the next and subsequent paper, is displaced toward the U-shaped outer paper guide.
Therefore, after the retard roller 41 moves away, the paper leading edge regulating ribs 60 and 60 come into contact with the leading edge of the succeeding paper P2, which is the next or subsequent paper, and restrict displacement to the downstream side in the feeding direction. it can.

  That is, it is possible to reliably prevent the subsequent paper P2 from being sent downstream in the feed direction. As a result, it is possible to prevent so-called accompanying paper feeding in which the succeeding paper P2 is sent along with the preceding paper P1. The accompanying paper feed is likely to occur when feeding a particularly large size paper P in which the area where the subsequent paper P2 and the preceding paper P1 come into contact with each other is increased. Specifically, it tends to occur in A3 size or larger. In other words, if the size is A4 size or less, the contact area is small, so that there is less possibility of accompanying paper feeding.

At this time, the amount of bending of the succeeding paper P2 can be reduced by moving the pickup roller 21 away. That is, the posture of the succeeding paper P2 can be made as straight as possible. Therefore, the leading edge of the succeeding paper P2 can be positively abutted against the paper leading edge regulating ribs 60, 60.
Further, the trailing edge of the preceding paper P1 acts to push the leading edge of the succeeding paper P2 toward the U-shaped outer paper guide portion that is outside the U-shaped path. Therefore, the leading edge of the succeeding paper P2 can be positively brought into contact with the paper leading edge regulating ribs 60, 60.

As a result, the accompanying paper feeding can be reliably prevented. That is, it is possible to prevent the accompanying paper feeding without providing a so-called return lever provided in the prior art.
Further, the retard roller 41 can be moved away at a timing earlier than that of the prior art. As a result, the so-called back tension due to the load of the retard roller 41 can be reduced at an early timing. For example, when the leading edge of the uppermost sheet P1 reaches the second assist roller 51, the separation roller 41 may start to move away.

FIG. 5 is a side view showing the operation after the retard separation in the printer according to the present invention.
As shown in FIG. 5, when the preceding sheet P1, which is the uppermost sheet with respect to the intermediate drive roller 50 from the state of FIG. 4, is sent downstream in the feed direction, the trailing edge of the preceding sheet P1 is moved to the intermediate drive. Pass between the roller 50 and the retard roller 41.

  Here, an entrainment prevention unit 13 is provided inside the U-shaped path. Specifically, it is provided so as to cover the intermediate drive roller 50 on the upstream side in the feed direction from the nip point N between the intermediate drive roller 50 and the retard roller 41 in the feed direction Y. Therefore, the entanglement prevention unit 13 can prevent the subsequent paper P2 from coming into contact with the intermediate drive roller 50.

As a result, there is no possibility that the intermediate driving roller 50 directly applies the feeding force to the subsequent paper P2.
The leading edge of the preceding paper P1 is nipped by the transport roller pair 71. Thereafter, skew removal is performed, and the preceding sheet P1 is recorded by the recording unit 80 while being conveyed downstream in the feeding direction by the conveying roller pair 71. Then, the paper is discharged to a discharge tray (not shown) in front of the printer 1 by a discharge unit (not shown).

FIG. 6 is a perspective view showing a feed roller pair and switching means according to the invention.
As shown in FIG. 6, a plurality of feed roller pairs 96 are arranged in the width direction X of the paper P. Specifically, the feed roller pair 96 is configured by first to fifth roller pairs 96a to 96e. The intermediate drive roller 50 has first to fifth intermediate rollers 50a to 50e on the same axis. That is, the first to fifth intermediate rollers 50a to 50e are provided to rotate integrally. On the other hand, the second assist roller 51 has first to fifth rollers 51a to 51e. And the 1st-5th intermediate | middle roller 50a-50e and the 1st-5th roller 51a-51e respectively become a pair, and comprise the 1st-5th roller pair 96a-96e.

  Also, the first to fifth rollers 51a to 51e are rotatably held by roller holders 54, 54, respectively. Furthermore, the feed roller pair 96 is provided with a switching means 4 that can relatively move the intermediate drive roller 50 and the second assist roller 51 toward and away from each other. Specifically, the intermediate driving roller 50 and the second assist roller 51 are configured to be able to switch between a first state in which the intermediate driving roller 50 and the second assist roller 51 are close to each other and a separated second state. Furthermore, the switching means 4 is provided so that it can switch about each of the feed roller pair 96. FIG.

That is, it is configured such that one of the plurality of feed roller pairs 96 (96a to 96e) can be selected to be in the first state and the other can be in the second state.
In the present embodiment, the second assist roller side is configured to move toward and away from the intermediate drive roller 50. However, the present invention is not limited to this. Conversely, a configuration in which the intermediate drive roller side moves toward and away from the second assist roller 51 may be employed. Moreover, the structure which both move in a contact / separation direction may be sufficient.

  The switching means 4 has a cam shaft 53 and a plurality of roller holders 54, 54... For holding the first to fifth rollers 51a to 51e, respectively. Among these, the camshaft 53 is formed with first to fifth cams 53a to 53e. Support shafts 55 and 55 are formed on one end side of the roller holders 54 and 54. On the other hand, first to fifth cam followers 54a to 54e that engage with the first to fifth cams 53a to 53e, respectively, are formed on the other end side of the roller holders 54, 54.

  In the roller holders 54, 54..., The first to fifth rollers 51a to 51e are disposed between the support shafts 55 and 55 and the first to fifth cam followers 54a to 54e. The first to fifth cam followers 54a to 54e of the roller holders 54, 54,... Receive the action of the first to fifth cams 53a to 53e, so that the roller holders 54, 54. It is configured to be able to swing around 55 as a fulcrum.

In the present embodiment, the cam shaft 53 is configured to rotate by the power of the separation motor 92. Then, the first state to the second state can be switched by the first to fifth cams 53a to 53e acting on the first to fifth cam followers 54a to 54e.
Of course, the motor for rotating the cam shaft 53 is not limited to the separation motor 92.

In the present embodiment, the first cam 53a, the fourth cam 53d, and the fifth cam 53e have the same shape and the same phase. The second cam 53b has a different shape and a different phase from the other cams. Similarly, the third cam 53c has a different shape and a different phase from the other cams. The reason is that, as will be described in detail later, the second roller 51b or the third roller 51c is selected to be in the first state, and the other rollers are set to a second state different from the first state of the selected roller. is there.
In the present embodiment, the first to fifth cams 53a to 53e are provided on the single cam shaft 53 as the switching means 4, but the present invention is not limited to this. A configuration may be adopted in which a power source such as an individual motor is provided for each, and the power sources are switched independently.

Next, the skew removal operation will be described.
FIG. 7 is a side view showing an initial biting state during skew removal according to the present invention. Moreover, what is shown in FIG. 8 is a side view which shows the state of each roller of the 2nd assist roller 51 in FIG.
As shown in FIG. 7, the control unit 90 drives the feeding motor 91 to rotate in the forward direction and rotates the intermediate driving roller 50 in the clockwise direction in the drawing. Further, the conveyance motor 94 is driven to rotate forward, and the conveyance drive roller 72 is rotated in the clockwise direction in the drawing.

  At this time, as shown in FIG. 8, the first to fifth rollers 51 a to 51 e of the second assist roller 51 are in the first state approaching the first to fifth intermediate rollers 50 a to 50 e of the intermediate drive roller 50. Accordingly, the feed roller pair 96 can reliably apply a feed force to the preceding paper P1. As a result, the preceding paper P1 can be reliably sent to the transport roller pair 71 as described above.

Accordingly, as shown in FIG. 7, the leading edge of the preceding paper P1 is nipped by the conveying roller pair 71 as described above. Then, the preceding paper P1 is fed until the leading end of the paper P1 is positioned downstream of the conveying roller pair 71 by a predetermined amount.
Here, the posture of the leading edge of the paper P <b> 1 may be inclined with respect to the nip line of the transport roller pair 71. This is so-called skew. The nip line is in the X-axis direction.
Therefore, the following operation is performed to remove the inclination of the sheet P1 with respect to the nip line, so-called skew removal.

FIG. 9 is a side view showing a discharge state during skew removal according to the present invention.
As shown in FIG. 9, the controller 90 stops the feeding motor 91 and stops the intermediate driving roller 50 from the state of FIG. 7. Further, the transport motor 94 is switched to the reverse drive, and the transport drive roller 72 is rotated counterclockwise in the drawing. Accordingly, the leading edge of the preceding paper P <b> 1 is fed back to the upstream side of the transport roller pair 71 by the transport roller pair 71. This is a so-called discharge operation.
At this time, the intermediate drive roller 50 is stopped. Accordingly, the preceding paper P1 can be bent between the feed roller pair 96 including the intermediate drive roller 50 and the second assist roller 51 in the feed direction Y and the transport roller pair 71. The leading edge of the preceding paper P1 can be made to follow the nip line of the transport roller pair 71.

Here, when the paper P1 is inclined with respect to the nip line in the state shown in FIG. 7, one end side in the width direction X of the paper P1 is greatly bent as shown by a solid line in FIG. 9, and the width of the paper P1 shown by a chain line is shown. The other end side in the direction X is slightly bent. Further, the magnitude of the difference between the one end side and the other end side in the width direction X of the paper P1 is proportional to the magnitude of the inclination of the front end of the paper in the state shown in FIG.
If the paper P1 is not inclined with respect to the nip line in the state shown in FIG. 7, the one end side and the other end side in the paper width direction X in FIG.

FIGS. 10A and 10B are plan views showing an operation concept in the case of paper sizes A4 and A3. Of these, FIG. 10A shows a state in which the leading edge of the sheet follows the nip line and before the trailing edge side rotates. On the other hand, FIG. 10B shows a state in which the leading edge of the sheet follows the nip line and the trailing edge side has rotated.
Moreover, what is shown to FIG. 11 (A) (B) is a side view which shows the state of the 2nd assist roller in FIG. Among these, FIG. 11 (A) is a figure which shows the relationship between a 2nd intermediate | middle roller and a 2nd roller. On the other hand, FIG. 11 (B) is a diagram showing the relationship between the first, third to fifth intermediate rollers and the first, third to fifth rollers.

As shown in FIGS. 10A and 10B and FIGS. 11A and 11B, the controller 90 determines the paper size and selects a roller to be in the first state.
The method for determining the paper size may be determined from the recording data by the control unit 90 as the size determination means, or a sensor as a width size detection means for detecting the paper width upstream of the transport roller pair 71 in the feed direction. You may comprise so that it may judge by providing.

Specifically, when the paper size is A4 (reference symbol P5) and A3 (reference symbol P6), the control unit 90 selects the second roller 51b by the switching unit 4 to be in the first state. And let other 1st roller and 3rd-5th roller 51a, 51c-51e be a 2nd state. That is, in the feed roller pair 96, only the second intermediate roller 50b and the second roller 51b hold the paper P (P5, P6).
Here, the position of the 2nd roller 51b in the width direction X is provided in the position nearest to the center of A4 and A3 size paper (P5, P6) among the 1st-5th rollers 51a-51e. And

  For example, as shown in FIG. 10A, when the leading edge of the paper (P5, P6) follows the nip line L, the right-side deflection amount (C1) of the paper (P5, P6) is the left-side deflection amount. (C2) may be larger. In such a case, the rear ends of the sheets (P5, P6) are inclined so that the right side in the width direction is located on the downstream side in the feeding direction compared to the left side. Here, the bending C of the sheets (P5, P6) acts to push the rear end side of the sheets (P5, P6) to the upstream side in the feed direction. Since the right side deflection amount (C1) is larger than the left side deflection amount (C2), the right side deflection C1 pushes the rear end side of the paper (P5, P6) more strongly to the upstream side in the feeding direction than the left side deflection C2. Acts as follows.

  Accordingly, as shown in FIG. 10B, the rear end side of the sheets (P5, P6) is displaced in the clockwise direction in the drawing with the place where the second intermediate roller 50b and the second roller 51b are pinched (the fulcrum) Rotate. At this time, when the deflection amount (C1 ′) on the right side and the deflection amount (C2 ′) on the right side of the sheets (P5, P6) are substantially the same, the pressing action toward the upstream side becomes substantially equal. The displacement (rotation) on the rear end side of (P5, P6) stops. That is, the posture of the rear end of the paper (P5, P6) is substantially equal to the posture of the front end.

Even when a space for sufficiently bending the paper P cannot be secured, the posture of the rear end of the paper can be made substantially equal to the posture of the front end. That is, it is effective in a configuration in which a space for sufficiently bending the paper P cannot be secured.
In particular, the stiffness of the paper P is relatively strong and is effective when the paper P is fed along the U-shaped outer paper guide 11.

  Note that when the leading edge of the paper (P5, P6) follows the nip line L, the deflection amount on the left side in the width direction of the paper (P5, P6) may be larger than the deflection amount on the right side. In such a case, according to the same principle as described above, the rear end side of the paper (P5, P6) is displaced counterclockwise in the drawing with the location where the second intermediate roller 50b and the second roller 51b are sandwiched as a fulcrum ( Rotate. Accordingly, the posture of the trailing edge of the paper (P5, P6) is substantially equal to the posture of the leading edge.

FIGS. 12A and 12B are plan views showing an operation concept in the case of the paper size A2. Among these, FIG. 12A shows a state where the leading edge of the paper follows the nip line and before the trailing edge side rotates. On the other hand, FIG. 12B shows a state in which the leading edge of the sheet follows the nip line and the trailing edge side has rotated.
Moreover, what is shown to FIG. 13 (A) (B) is a side view which shows the state of the 2nd assist roller in FIG. Among these, FIG. 13A is a diagram showing the relationship between the third intermediate roller and the third roller. On the other hand, FIG. 13B is a diagram showing the relationship among the first, second, fourth, and fifth intermediate rollers and the first, second, fourth, and fifth rollers.

As shown in FIGS. 12A and 12B and FIGS. 13A and 13B, when the paper size is A2 (reference P7), the control unit 90 selects the third roller 51c by the switching means 4. Set to the first state. The other first, second, fourth, and fifth rollers 51a, 51b, 51d, and 51e are set in the second state. That is, in the feed roller pair 96, only the third intermediate roller 50c and the third roller 51c are in a state of holding the paper (P7).
Here, the position of the 3rd roller 51c in the width direction X shall be provided in the position nearest to the center of A2 size paper (P7) among the 1st-5th rollers 51a-51e.

  For example, as shown in FIG. 12A, when the leading end of the sheet (P7) follows the nip line L, the amount of deflection (C3) on the right side in the width direction of the sheet (P7) is greater than the amount of deflection on the left side (C4). May be big. In this case, as in the case of the A4 (reference P5) and A3 (reference P6) sizes described above (see FIG. 10), the right-side deflection C3 feeds the rear end side of the sheet (P7) more than the left-side deflection C4. Acts to push strongly upstream.

  Accordingly, as shown in FIG. 12B, the rear end side of the sheet (P7) is displaced (rotated) in the clockwise direction in the drawing with the position where the third intermediate roller 50c and the third roller 51c are pinched as fulcrums. To do. At this time, as in the case of the A4 (reference P5) and A3 (reference P6) sizes described above (see FIG. 10), the right deflection amount (C3 ′) and the left deflection amount (C4 ′) of the paper (P7). ) Is substantially the same, the action of pushing to the upstream side is substantially equal, so that the displacement (rotation) on the rear end side of the sheet (P7) stops. That is, the posture of the trailing edge of the sheet (P7) is substantially equal to the posture of the leading edge.

FIG. 14 is a side view showing a cueing state at the time of skew removal according to the present invention.
As shown in FIG. 14, from the state of FIG. 9, the control unit 90 drives the feeding motor 91 in the normal direction to rotate the intermediate drive roller 50 in the clockwise direction in the drawing. Further, the conveyance motor 94 is driven to rotate forward, and the conveyance drive roller 72 is rotated in the clockwise direction in the drawing. Therefore, the leading end of the sheet P1 that is not inclined with respect to the nip line can be nipped by the conveying roller pair 71. Then, the leading edge of the preceding paper P1 is sent to the recording start position, and the feeding motor 91 and the conveying motor 94 are stopped. This is a so-called cueing operation.
Here, the recording start position refers to a position facing a nozzle row (not shown) of the recording head 82.

  At this time, as described in FIGS. 10 to 13, the feed roller pair (for example, 96b in the case of A3 size) to be in the first state is selected according to the paper size, and the other feed roller pairs (for example, A3 size of A3 size) are selected. In this case, 96a, 96c to 96e) are set to the second state. That is, after the leading edge of the paper P is pinched by the transport roller pair 71, one feed roller pair to be in the first state is selected, and the other feed roller pairs are switched to the second state. This is because the feeding force may become insufficient if the other feeding roller pairs are switched to the second state before the leading edge of the paper P is clamped by the conveying roller pair 71. That is, in order to ensure that the leading edge of the paper P is pinched by the transport roller pair 71, all the feed roller pairs (96a to 96e) are in the first state until the paper is pressed. .

Then, according to the paper size, the feed roller pair to be in the first state (for example, 96b for the A3 size) is selected, and the other feed roller pairs (for example, 96a, 96c to 96e for the A3 size) are set to the second state. By setting the state, the posture of the trailing edge of the paper P can be made to follow the posture of the leading edge as described above. That is, the difference in the amount of deflection between the one end side and the other end side in the width direction X of the paper P between the feed roller pair 96 and the transport roller pair 71 in the feed direction Y is removed.
Therefore, after that, when the paper P1 is transported by the transport roller pair 71 and is recorded by the recording unit 80, there is no possibility that a difference in feed force in the width direction on the left and right is caused by the difference in the left and right bending amounts. That is, there is no risk of the so-called cumulative skew described above. As a result, good recording can be performed.

However, there may be a case where the difference between the one end side and the other end side in the width direction X of the paper P is not sufficiently removed between the feed roller pair 96 and the transport roller pair 71 in the feed direction Y. .
In such a case, as described in the related art, due to the difference between the deflection amount on the one end side and the deflection amount on the other end side, the transport amount on the one end side in the pair of transport rollers 71 and the transport amount on the other end side. There may be a difference between
Therefore, in order to sufficiently remove the difference between the bending amount on the one end side and the bending amount on the other end side, the following operation is performed.

FIG. 15 is a side view showing a normal rotation operation after skew removal according to the present invention.
As shown in FIG. 15, from the state of FIG. 14, the controller 90 first separates the first to fifth rollers 51 a to 51 e that are all of the second assist roller 51 from the intermediate drive roller 50 by the switching unit 4. To the second state.
Here, the 2nd assist roller 51 made into a 2nd state should just be a roller which opposes the paper P at least among the 1st-5th rollers 51a-51e. This is because an appropriate feeding force described later is applied to the paper P.

  It should be noted that, of course, the intermediate drive roller 50 may be configured to move in a direction away from the second assist roller 51. This is also because in this case, the same effects as those described below can be obtained. In the present embodiment, the reason why the second assist roller 51 is configured to move is that the intermediate driving roller 50 is driven. That is, it is easier to move the second assist roller 51, which is the driven rotating side, than to move the intermediate driving roller 50, which is the driving side.

Next, the feeding motor 91 is driven to rotate forward, and the intermediate driving roller 50 is rotated in the clockwise direction in the drawing. During this time, the transfer motor 94 remains stopped.
At this time, the second assist roller 51 is separated from the intermediate drive roller 50. Therefore, the intermediate drive roller 50 can apply an appropriate feed force to the downstream side in the feed direction with respect to the paper P1 while sliding between the paper P1 and the outer periphery of the intermediate drive roller 50.

  Here, the “appropriate feeding force” is the degree to which the sheet P1 can be bent so as to be pressed outside the U-shaped feeding path between the feeding roller pair 96 and the conveying roller pair 71 in the feeding direction Y. Refers to the feed force. When the sheet P1 cannot be deflected further outward, a slip always occurs between the sheet P1 and the outer periphery of the intermediate drive roller 50, and so-called sheet jam occurs in which the sheet P1 is jammed in the feed path. There is no fear.

  As a result, it is possible to increase the amount of deflection of the paper P1 that has occurred between the feed roller pair 96 and the transport roller pair 71 in the feed direction Y. Here, between the feed roller pair 96 and the transport roller pair 71 in the feed path, a section R curved at least partially in side view is formed. Then, the sheet P1 can be pressed against the outside of the U-shaped feed path, that is, the curved outside of the section, so that the sheet P1 cannot be bent any more. That is, a predetermined deflection amount can be obtained.

Furthermore, it is possible to reliably eliminate the difference between the bending amount on the one end side of the paper P1 and the bending amount on the other end side. As a result, there is no possibility of a difference between the transport amount on the one end side and the transport amount on the other end side of the transport roller pair 71 at the time of subsequent recording.
Further, when the intermediate drive roller 50 is driven to rotate forward, the pickup roller 21 is in a state of moving away from the paper P as described above (see FIG. 5). Therefore, there is no possibility of preventing the difference between the deflection amount on the one end side of the paper P1 and the deflection amount on the other end side from being eliminated.

Furthermore, if the intermediate drive roller 50 is driven in reverse, the amount of bending of the paper P1 that has occurred between the feed roller pair 96 and the transport roller pair 71 in the feed direction Y can be reduced.
Then, similarly to the case where the intermediate drive roller 50 is driven to rotate forward, the difference between the deflection amount on the one end side of the paper P1 and the deflection amount on the other end side can be eliminated.

Here, the reason why the intermediate drive roller 50 is configured to rotate forward in this embodiment is that the sheet P1 moves away from the intermediate drive roller 50 when the intermediate drive roller 50 is driven forward. .
Assuming that the intermediate drive roller is driven in reverse, the sheet P1 behaves like being wound around the intermediate drive roller.
Therefore, in the present embodiment, it is possible to reduce the rotational load of the intermediate drive roller 50 as compared with the case where the intermediate drive roller is reversely driven.

  Thereafter, the feeding motor 91 and the conveying motor 94 are driven to rotate forward, and the intermediate driving roller 50 and the conveying driving roller 72 are rotated clockwise in the drawing. At this time, the outer peripheral speed V1 of the intermediate driving roller 50 is desirably the same as the outer peripheral speed V2 of the transport driving roller 72. This is because there is no need to bend the paper P1. As described above, the preceding sheet P1 is recorded by the recording unit 80 while being conveyed downstream in the feed direction by the conveying roller pair 71. Then, the paper is discharged to a discharge tray (not shown) in front of the printer 1 by a discharge unit (not shown).

  Note that the intermediate driving roller 50 may be rotated in the clockwise direction in the drawing without stopping the forward driving of the transport driving roller 72 when the paper P1 is cued. That is, after the skew is removed, the conveyance drive roller 72 is driven to rotate forward so that the leading edge of the paper P1 is nipped by the conveyance roller pair 71. Immediately after this, a feed roller pair (for example, 96b for A3 size) to be in the first state is selected according to the paper size, and other feed roller pairs (for example, 96a, 96c to 96e for A3 size) are selected. Set to the second state. Furthermore, immediately after this, the first to fifth rollers 51 a to 51 e that are all of the second assist roller 51 are moved away from the intermediate drive roller 50. Then, the intermediate drive roller 50 may be driven to rotate forward while slipping between the paper P1.

At this time, the outer peripheral speed V <b> 1 of the intermediate driving roller 50 is faster than the outer peripheral speed V <b> 2 of the transport driving roller 72. This is because when the transport roller pair 71 transports the paper P1, the difference between the left and right deflection amounts in the width direction on the rear end side of the paper P1 is substantially eliminated.
In such a case, the timing from when the feeding of the paper P1 is started to when the recording is started can be made earlier as compared with the case where the forward driving of the intermediate driving roller 50 is stopped. As a result, the throughput can be shortened.
The speed V1 of the intermediate drive roller 50 is preferably about 25 to 30% higher than the speed V2 of the transport drive roller 72. This is because the paper P1 can be bent appropriately.

Furthermore, in the present embodiment, the so-called “biting and discharging method” skew removal operation has been described, but the so-called “butting method” may be used.
Here, the “abutment method” is a transport roller in a state where the leading end of the paper P1 is stopped or reversely driven by the pair of feed rollers 96 as described above. This is a system in which the posture of the tip is made to follow the nip line by pressing against the nip line of the pair 71. That is, it refers to a system in which the leading edge of the sheet P1 is brought into contact with the conveying roller pair 71 so that the attitude of the leading edge follows the nip line.

It should be noted that between the feed roller pair 96 and the transport roller pair 71, the paper P1 may be bent so that the posture of the leading edge follows the nip line, or the leading edge posture is allowed to follow the nip line without bending. Also good.
If the paper is not bent, the feed roller pair to be in the first state is selected according to the size of the paper and the other feed roller pair is switched to the second state immediately before the leading edge of the paper abuts the transport roller pair. desirable. This is because, since the stiffness of the paper is relatively strong, the skew is removed without being bent, so that when the front end of the paper is abutted, the rear end side of the paper can be rotated to correct the posture.

Here, the stiffness of the paper refers to the elasticity and rigidity of the paper. When the stiffness of the paper is strong, it is easy to transmit the rotating force to the rear end side of the paper, so that the posture of the rear edge can be made to follow the posture of the front end of the paper almost simultaneously with the nip line. .
On the other hand, when bending, a feed roller pair (for example, 96b for A3 size) to be in the first state is selected according to the paper size, and other feed roller pairs (for example, 96a, 96c to 96e for A3 size). ) Is set to the second state in the same manner as the “eating and discharging method”.

FIG. 16 is a side view showing how the subsequent sheet is picked up in the present invention.
As shown in FIG. 16, after the preceding paper P1 is conveyed to the recording unit 80, the paper P can be continuously fed. Specifically, the control unit 90 detects the trailing edge of the paper P <b> 1 with the paper detector 75, and then moves the retard roller 41 and the second assist roller 51 closer to the intermediate drive roller 50. More specifically, the cam portion 45 is rotated by the separation motor 92 and the retard holder (not shown) approaches the intermediate drive roller 50 by the biasing force of the biasing spring (not shown). Rock.

Similarly, the separation mechanism (not shown) is operated to move the second assist roller 51 in a direction approaching the intermediate drive roller 50.
Further, the control unit 90 drives the arm motor 93 to swing the arm unit 22 around the arm shaft 23 in a direction in which the pickup roller 21 approaches the paper P placed on the cassette unit 14.

  At this time, the succeeding paper P2 held by the paper leading edge regulating ribs 60, 60 is displaced toward the intermediate drive roller by the approaching movement of the retard roller 41. Then, nipping is performed by the intermediate drive roller 50 and the retard roller 41. Therefore, the leading edge of the succeeding paper P2 is released from the restricted state by the paper leading edge regulating ribs 60, 60. In this state, as described above, the intermediate drive roller 50 and the pickup roller 21 are rotated clockwise in the drawing.

At this time, if there is one subsequent sheet P2 held by the sheet leading edge regulating ribs 60, 60, the one sheet P2 is fed downstream in the feeding direction.
If there are a plurality of subsequent sheets P2, P3,... Held by the sheet leading edge regulating ribs 60, 60, the relationship of friction coefficient μ4> friction coefficient μ2 and friction coefficient μ5> friction coefficient μ2 holds as described above. .

  Therefore, the feed force acting on the uppermost sheet P2 with respect to the intermediate drive roller 50 can be made larger than the feed force acting on the subsequent sheet P3. That is, the retard roller 41 separates the next and subsequent sheets P3, and only the uppermost sheet P2 can be sent downstream in the feed direction. At this time, the leading edge of the uppermost sheet P2 is displaced toward the intermediate driving roller side by the approaching movement of the retard roller 41 as described above, so there is no possibility of being regulated by the sheet leading edge regulating ribs 60 and 60.

  In the present embodiment, the feed path is U-shaped as viewed from the side, but is not limited thereto. It may be a straight line as viewed from the side, or may have a section R that is partially curved as viewed from the side. Similarly, in this case as well, after the skew is removed, the intermediate drive roller 50 in the state where the second assist roller 51 is separated can be driven to rotate in the forward direction so that the difference between the bending amounts in the width direction can be eliminated. A configuration having at least a section R that is curved in side view is desirable. This is because it can be determined to which side the sheet P bends in the thickness direction Z of the sheet P.

  The feeding unit 3 as the medium feeding device of the present embodiment includes first to fifth intermediate rollers 50a to 50e that are intermediate driving rollers 50 as feeding driving rollers that are driven by power, and first feeding rollers that are driven to rotate. Feed rollers that have first to fifth rollers 51a to 51e that are two assist rollers 51 and are arranged in the width direction X of the paper P, which is an example of a medium to be fed, and feed the paper P downstream in the feed direction The first to fifth roller pairs 96a to 96e which are the pair 96, the transport driving roller 72 which is disposed on the downstream side in the feeding direction from the first to fifth roller pairs 96a to 96e, and is driven by power, and the transport driven to be driven and rotated A pair of transport rollers 71 having a roller 73 and transporting the paper P sent by the first to fifth roller pairs 96a to 96e downstream in the feed direction. A U-shaped outer paper guide portion 11 and an inner paper guide portion 12 as medium guide path portions for guiding the paper P from the first to fifth roller pairs 96a to 96e to the transport roller pair 71, and the first to fifth roller pairs. The first to fifth intermediate rollers 50a to 50e of 96a to 96e and the first to fifth rollers 51a to 51e are relatively moved toward and away from each other, and the first to fifth intermediate rollers 50a to 50e and the first to first rollers are moved. The feeding unit 3 includes a switching unit 4 that switches between a first state in which the five rollers 51a to 51e are close to each other and a second state in which the five rollers 51a to 51e are separated from each other. When feeding from the five roller pairs 96a to 96e to the conveying roller pair 71, the first to fifth roller pairs 96a to 96e are set to the first state, and the first to fifth intermediate rollers 50a to 50a, which are the intermediate drive rollers 50, are used. e is driven to rotate forward to feed the paper P to the downstream side in the feed direction, and the posture of the leading edge, which is the downstream end of the feed direction of the paper P, is copied in the direction of the nip line L that is a line formed by the circumscribed portion of the transport roller pair 71. When the paper is fed, the first roller to the first roller pair 96a to 96e, depending on the size of the paper (P5 to P7), the second roller in the case of the feed roller pair (for example, A3 (reference P6) size) in the first state. The pair 96b) is selected, and the other feed roller pairs (for example, the first, third to fifth roller pairs 96a, 96c to 96e in the case of A3 (reference P6) size) are set to the second state. It is characterized by.

  In the present embodiment, the switching means 4 includes a rotatable cam shaft 53, first to fifth cams 53a to 53e as a plurality of cam portions provided on the cam shaft, The first to fifth cams 53a to 53e are provided on the roller holders 54, 54... On the first to fifth rollers 51a to 51e side of the first to fifth roller pairs 96a to 96e from the fifth cams 53a to 53e. And first to fifth cam followers 54a to 54e as cam follower portions respectively engaged with the first state and the second cam follower 54a to 54e are displaced. It is the structure which switches a state.

  The cam follower is provided on the first to fifth intermediate rollers 50a to 50e side from the first to fifth cams 53a to 53e, and the first to fifth intermediate rollers 50a to 50e are displaced. Also good. Moreover, you may comprise a cam follower part in the both sides of the 1st-5th intermediate | middle roller 50a-50e and the 1st-5th roller 51a-51e, and both displace in the contact / separation direction. This is because it is possible to obtain the same operational effects as in such a case.

  Furthermore, in the present embodiment, when the posture of the leading edge of the paper P is made to follow the nip line L, the feeding unit 3 is the center in the width direction of the paper P to be fed among the first to fifth roller pairs 96a to 96e. Is selected as the pair of feed rollers to be in the first state, and another pair of feed rollers (for example, A3 (reference P6) size). In this case, the first, third to fifth roller pairs 96a, 96c to 96e) are in the second state.

Further, in the present embodiment, the U-shaped outer sheet guide unit 11 and the inner sheet guide unit 12 have a section R that is curved in side view.
Furthermore, in the present embodiment, when the posture of the leading edge of the paper P is made to follow the nip line L of the transport roller pair 71, the transport driving roller 72 is driven to rotate forward so that the leading edge of the paper P is moved to the transport roller pair. 71, and the conveyance driving roller 72 is driven in reverse to bend the paper P between the first to fifth roller pairs 96a to 96e and the conveyance roller pair 71 in the feeding direction Y, whereby the leading edge of the paper P is Following the nip line L of the transport roller pair 71, when the transport drive roller 72 is driven to rotate forward and the leading end side of the paper P is sandwiched between the transport roller pair 71, the feed roller pair (for example, A3 ( In the case of the size P6), the second roller pair 96b) is selected, and in the case of other feed roller pairs (for example, A3 (reference P6) size, the first, third to fifth rows) Over pairs 96a, characterized in that it is configured to the second state 96c~96e).

  In the present embodiment, the front end of the paper P is made to follow the nip line L of the transport roller pair 71, and then the transport drive roller 72 and the first to fifth intermediate rollers 50a to 50e that are the intermediate drive roller 50 are rotated forward. By driving, the leading edge of the paper P is sandwiched between the transport roller pair 71, and the feed roller pair to be in the first state (for example, the second roller pair 96b in the case of A3 (reference numeral P6) size) is selected. After the first feed roller pair (for example, the first, third to fifth roller pairs 96a, 96c to 96e in the case of A3 (reference P6) size) is set to the second state, the feed unit 3 includes first to fifth feeds. Among the roller pairs 96a to 96e, at least the feed roller pair that faces the paper P (for example, at least the first to third roller pairs 96a to 96c in the case of A3 (reference P6) size) is the first one. A state, characterized in that the paper P is driven forward first to fifth intermediate roller 50a~50e an intermediate driving roller 50 is configured to modeled after the U-shaped outer sheet guide unit 11.

  The printer 1, which is an example of a recording apparatus according to the present embodiment, has a feeding unit 3 as a medium feeding unit that feeds a sheet P, which is an example of a recording medium, to the downstream side in the feeding direction, and a sheet P sent by the feeding unit 3. On the other hand, a recording unit 80 for recording by the recording head 82 is provided.

In the present embodiment, a so-called one-sided configuration is used in which the paper is aligned at one end in the width direction X even when the paper sizes are different. However, the present invention is not limited to this. Even when the paper sizes are different, a so-called center-aligned configuration in which the sheets are aligned at the center in the width direction X may be used. In such a case as well, the same operation effect can be obtained by selecting the central roller in the width direction X from the plurality of second assist rollers 51 to be in the first state and setting the other rollers to be in the second state. .
Further, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.

1 printer, 2 base unit, 3 feeding unit, 4 switching means, 10 feeding unit,
11 U-shaped outer paper guide, 12 inner paper guide, 13 entanglement prevention,
14 cassette section, 15 pad section, 20 pickup section,
21 pickup roller, 22 arm part, 23 arm shaft, 30 preliminary separation part,
31 bank separation unit, 40 separation unit, 41 retard roller, 43 swing mechanism,
45 cam portion, 48 first assist roller, 50 intermediate drive roller,
50a first intermediate roller, 50b second intermediate roller, 50c third intermediate roller,
50d 4th intermediate roller, 50e 5th intermediate roller, 51 2nd assist roller,
51a 1st roller, 51b 2nd roller, 51c 3rd roller,
51d 4th roller, 51e 5th roller, 52 3rd assist roller,
53 cam shaft, 53a first cam, 53b second cam, 53c third cam,
53d 4th cam, 53e 5th cam, 54 roller holder,
54a 1st cam follower, 54b 2nd cam follower,
54c 3rd cam follower, 54d 4th cam follower,
54e Fifth cam follower, 55 spindle, 60 paper leading edge regulating rib, 70 transport section,
71 transport roller pair, 72 transport drive roller, 73 transport driven roller,
74 driven roller holder, 75 paper detector, 76 sensor unit,
77 Paper detection lever, 80 recording unit, 81 medium support unit, 82 recording head,
90 control unit, 91 feeding motor, 92 separation motor,
93 motor for arm, 94 transport motor, 96 feed roller pair,
96a first roller pair, 96b second roller pair, 96c third roller pair,
96d 4th roller pair, 96e 5th roller pair, C deflection, C1 right side deflection,
C2 left side deflection, C3 right side deflection, C4 left side deflection, L nip line,
N nip point, P paper, P1 preceding paper, P2 following paper,
P5 (A4 size) paper, P6 (A3 size) paper,
P7 (A2 size) paper, R curved section, X width direction, Y feed direction,
Z (paper) thickness direction

Claims (7)

A feed roller pair that has a feed drive roller that is driven by power and a feed driven roller that is driven to rotate; a plurality of feed roller pairs that are arranged in the width direction of the medium to be fed and feed the medium to be fed downstream in the feed direction;
The feed roller pair is disposed on the downstream side in the feed direction, has a transport drive roller that is driven by power, and a transport driven roller that is driven to rotate, and feeds the medium to be fed sent by the feed roller pair to the downstream side in the feed direction. A pair of transport rollers to transport,
A medium guide path for guiding a medium to be fed from the pair of feed rollers to the pair of transport rollers;
The feed driving roller and the feed driven roller of the plurality of feed roller pairs are relatively moved toward and away from each other, and the first state in which the feed drive roller and the feed driven roller are close to each other and the separated second state A medium feeding device comprising switching means for switching between states,
When the medium feeding device feeds the medium to be fed from the plurality of feeding roller pairs to the pair of conveying rollers, the plurality of feeding roller pairs are set to the first state, and the feeding driving roller is driven to rotate in the forward direction. To the downstream side in the feed direction,
When the posture of the tip which is the downstream end in the feeding direction of the medium to be fed is copied in a line direction formed by a circumscribed portion of the conveying roller pair, the plurality of feeding roller pairs among the plurality of feeding roller pairs according to the size of the medium to be fed A medium feeding device configured to select a pair of feeding rollers to be in a first state and to set another pair of feeding rollers to be in the second state. The medium feeding device according to claim 1, wherein the switching means is
One rotatable camshaft,
A plurality of cam portions provided on the cam shaft;
A plurality of cam follower portions that are provided on at least one side of the feed driving roller and the feed driven roller of the plurality of feed roller pairs from the plurality of cam portions, and respectively engage with the plurality of cam portions;
A medium feeding device configured to switch between the first state and the second state when the cam follower portion is displaced.   3. The medium feeding device according to claim 1, wherein when the posture of the tip of the medium to be fed is copied in the linear direction, the medium feeding device is a medium to be fed among the plurality of pairs of feeding rollers. A medium feeding device having a configuration in which a pair of feeding rollers closest to the center in the width direction is selected as a pair of feeding rollers to be in the first state and another pair of feeding rollers is in the second state.   4. The medium feeding device according to claim 1, wherein the medium guide path portion has a side-curved section. 5. In the medium feeding device according to any one of claims 1 to 4, when the posture of the tip of the medium to be fed is made to follow the linear direction of the pair of transport rollers,
By causing the transport drive roller to rotate forward, the tip of the medium to be fed is sandwiched between the transport roller pair,
The leading edge of the medium to be fed is copied in the linear direction of the pair of conveying rollers by rotating the conveying driving roller in a reverse direction and bending the medium to be fed between the pair of conveying rollers and the pair of conveying rollers in the feeding direction. When the transport driving roller is driven to rotate forward and the leading end side of the medium to be fed is sandwiched between the transport roller pair, the transport roller pair to be in the first state is selected, and the other transport roller pair is selected as the second transport roller pair. A medium feeding device that is configured to be in the state In the medium feeding device according to any one of claims 1 to 5, after the front end of the medium to be fed follows the line direction of the pair of transport rollers,
The forward drive of the transport drive roller and the feed drive roller causes the leading edge of the medium to be fed to be sandwiched between the transport roller pair, and the feed roller pair to be in the first state is selected, and another feed roller pair Is set to the second state,
The medium feeding device sets at least the feeding roller pair facing the medium to be fed among the plurality of feeding roller pairs to be in the second state, and drives the feeding driving roller to rotate forward so that the medium to be fed becomes the medium guide path portion. A medium feeding device having a configuration for copying. Medium feeding means for feeding a recording medium downstream in the feeding direction;
A recording unit for recording with a recording head on a recording medium sent by the medium feeding means,
The medium feeding unit includes the medium feeding device according to any one of claims 1 to 6, and the recording medium is the recording medium.

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