JP5472599B2 - Medium feeding device and recording device - Google Patents

Description

The present invention has a feed drive roller that is driven by power and a feed driven roller that is driven to rotate, and a feed roller pair that feeds a medium to be fed to the downstream side in the feed direction, and is arranged downstream of the feed roller pair in the feed direction. A pair of transport rollers that have a transport drive roller that is driven by power and a transport driven roller that is driven to rotate, and that transports a medium to be transported sent by the pair of feed rollers to the downstream side in the feed direction, The present invention relates to a medium feeding device provided with a medium guide path section for guiding a medium from the pair of feeding rollers to the pair of conveying rollers, and a recording apparatus provided with 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, a medium feeding device provided in a recording apparatus includes a pickup roller, a guide path portion, a feeding roller pair, and a conveying roller pair. Among these, the pick-up roller is provided so as to pick up a sheet as a medium to be fed and feed it to the downstream side in the feeding direction. Further, the guide path portion is provided so as to form a feed path and guide the paper to be fed.

  Furthermore, the feed roller pair has a feed drive roller that is driven by power and a feed driven roller that is driven to rotate. The picked-up paper is provided so as to be further sent downstream in the feeding direction. Further, the pair of transport rollers has a transport driving roller that is driven by power and a transport driven roller that is driven to rotate. And it was comprised so that the paper sent by the said feed roller pair could be conveyed further downstream in a feed direction.

FIG. 12 is a side view showing an outline of the inside of the recording apparatus in the prior art.
As shown in FIG. 12, the feeding device 201 provided in the conventional recording apparatus 200 includes a pickup roller 203, a guide path unit 202, a feeding roller pair 205, and a conveying roller pair 208. The pickup roller 203 is provided so that the loaded paper can be picked up and sent downstream in the feeding direction. In addition, the guide path unit 202 is provided so as to form a feed path and guide the picked-up paper to the transport roller pair 208.

  Furthermore, the feed roller pair 205 has a feed drive roller 206 driven by power and a feed driven roller 207 that is driven to rotate. It was provided so that the picked-up paper could be sent further downstream in the feed direction. The conveyance roller pair 208 is configured to be able to further convey the sheet fed by the feed roller pair 205 to the recording unit 209 on the downstream side in the feeding direction.

  First, the picked-up paper enters the retard roller 204 that rotates with a predetermined load. When the paper is double-fed, so-called retard separation is performed. Then, only the uppermost sheet with respect to the feed drive roller 206 is sent to the transport roller pair 208 by the feed roller pair 205. First, the front end of the sheet is nipped by the conveyance roller pair 208. So-called initial bite. Next, the conveyance roller pair 208 is reversed, and the leading edge of the sheet is moved to the upstream side in the feeding direction from the nip point of the conveyance roller pair 208. This is a so-called discharge operation.

At this time, the feed roller pair 205 is in a stopped state. Therefore, the sheet can be bent between the feed roller pair 205 and the transport roller pair 208 as shown in FIG. The solid line shown in FIG. 12 is the posture of one end side 210 in the width direction X of the paper. On the other hand, the chain line indicates the posture of the other end side 211 in the width direction X of the paper. Here, the difference between the attitude of the one end side 210 and the attitude of the other end side 211 of the sheet increases as the attitude of the leading edge of the sheet with the initial bite is more inclined with respect to the nip line of the transport roller pair 208. Becomes larger.
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.

Then, the posture of the front end of the paper is made to follow the nip line of the transport roller pair 208, the transport roller pair 208 is rotated forward, and the front end of the paper is nipped again by the transport roller pair 208, so-called biting. Skew removal by the discharge method was executed.
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.

  Thereafter, the transport roller pair 208 transports the sheet to the recording unit 209, and recording on the sheet is performed by the recording unit 209. At this time, the retard roller 204 and the feed driven roller 207 were moved away from the feed drive roller 206. Therefore, it is possible to reduce so-called back tension, which is a resistance that acts so that the rear end side of the sheet is pulled upstream in the feeding direction during conveyance of the sheet by the conveyance roller pair 208.

Japanese Patent No. 3351509

However, even when the retard roller 204 and the feed driven roller 207 are moved away from the feed drive roller 206, the amount of bending of the one end side 210 in the sheet width direction X and the other end side in the sheet width direction X are as follows. It was not enough to eliminate the difference from the deflection amount of 211. Due to the bending of the paper between the feed roller pair 205 and the transport roller pair 208, the paper is pushed by the transport roller pair 208 to the downstream side in the feed direction. Therefore, there is a possibility that a difference occurs between the conveyance amount on one end side (210) in the width direction X and the conveyance amount on the other end side (211) in the width direction X due to the difference in the deflection amount. As a result, there is a possibility that a so-called cumulative skew in which the sheet is newly inclined with respect to the feeding direction during conveyance after the skew removal is generated.
In particular, when the paper guide path from the pickup to the conveying roller pair 208 is side-view curved, problems tend to occur when the paper size is A3 or larger.

  The present invention has been made in view of such a situation, and the object thereof is to provide a medium feeding device and a medium feeding device in consideration of stabilizing the posture of the medium to be fed with respect to the feeding direction. It is to provide a recording device.

  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 feeds the medium to be fed to the downstream side in the feed direction. A feed roller pair, a transport drive roller that is disposed downstream of the feed roller pair in the feed direction and is driven by power, and a transport driven roller that is driven to rotate, and a medium to be fed sent by the pair of feed rollers. A pair of transport rollers for transporting downstream in the feed direction, 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 pair of feed rollers The first state in which the feed driving roller and the feed driven roller are close to each other and the second state in which they are separated A medium feeding device comprising: a switching means for switching between the first and second feeding rollers, and the medium feeding device forwardly drives the feed driving roller of the feeding roller pair in the first state to feed the medium to be fed to the downstream side in the feeding direction. In this case, the posture of the leading end, which is the downstream end in the feeding direction of the medium to be fed, is made to follow the line direction formed by the part that circumscribes the pair of conveying rollers, and the conveying driving roller is driven to rotate forward so that the leading end side of the medium to be fed is In a state of being sandwiched between the pair of transport rollers, the pair of feed rollers is switched to the second state, and the feed drive roller is driven to rotate forward so that the medium to be fed follows the medium guide path. Features.

According to the first aspect of the present invention, the posture of the leading end of the medium to be fed can be made to follow a so-called nip line that is the linear direction of the pair of transport rollers. This is so-called skew removal. The skew removing operation may be a so-called “breaking-out discharge method” or “butting 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.

  Then, the feeding roller pair is set to the second state in a state where the leading end side of the medium to be fed is sandwiched between the pair of conveying rollers. Therefore, it is possible to follow the posture of the rear end side of the medium to be fed in the same manner as the front end. At this time, there is a possibility that the amount of deflection on both sides in the width direction of the medium to be fed remains different between the pair of feed rollers and the pair of transport rollers in the feed direction. That is, there is a possibility that the left and right deflection amounts are still in a state of difference.

  Therefore, in this aspect, the feed driving 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 bending of the medium to be fed can be made substantially uniform in the width direction, and the difference in the amount of bending on both sides of the medium to be fed 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, 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.

  According to a second aspect of the present invention, in the first aspect, after the front drive driving roller is driven to rotate forward so that the front end of the medium to be fed is sandwiched between the transport roller pair, the transport drive roller and the feed drive The roller is driven to rotate forward to send the medium to be fed to the downstream side in the feed direction, and the outer peripheral speed of the feed drive roller at this time is faster than the outer peripheral speed of the transport drive roller. Features.

According to the second aspect of the present invention, in addition to the same effects as the first aspect, the feed drive roller is moved at a speed faster than the outer peripheral speed of the transport drive roller while driving the transport drive roller in the normal direction. Drive. Accordingly, the timing at which the pair of transport rollers feeds the medium to be sent to the downstream side in the feed direction can be made faster than the configuration in which the feed drive roller is driven to rotate forward while the transport drive roller is stopped. .
Furthermore, since the feed driving roller is driven at a speed faster than the outer peripheral speed of the transport drive, the medium to be fed can be appropriately bent between the transport drive roller pair and the feed drive roller.

  Furthermore, the relative speed difference between the speed of the transport drive roller and the speed of the feed drive roller is reduced as compared to the configuration in which the transport drive roller is driven to rotate forward with the transport drive roller stopped. Is possible. Accordingly, it is possible to relatively reduce the amount of slip generated between the medium to be fed and the feed driving roller. As a result, it is possible to reduce the slip noise as compared with the configuration in which the feed drive roller is driven to rotate in the forward direction while the transport drive roller is stopped.

According to a third aspect of the present invention, in the first or second aspect, the medium guide path part has a side-curved section.
According to the third aspect of the present invention, in addition to the same effects as those of the first or second aspect, the medium guide path portion has a side-curved section. In the case of having the side-curved section, when there is a difference in the amount of bending in the width direction on the rear end side of the medium to be fed, simply sending the medium to be fed downstream in the feeding direction, The difference in the amount of bending is difficult to disappear. This is because the frictional resistance between the medium guiding path portion and the medium to be fed is increased as compared with the case where the side-curved section is not provided. For this reason, cumulative skew tends to occur. Therefore, the configuration in which the feed roller pair is switched to the second state and the feed drive roller is driven to rotate forward is particularly effective in such a case.

According to a fourth aspect of the present invention, in any one of the first to third aspects, a plurality of the feed roller pairs are arranged in the width direction of the medium to be fed.
According to the fourth aspect of the present invention, in addition to the same effects as any one of the first to third aspects, a plurality of the feed roller pairs are arranged in the width direction. A difference in the amount of bending tends to occur. Specifically, when the front end of the medium to be fed is made to follow the linear direction, the posture of the rear end side of the medium to be fed is firmly held by the plurality of feed roller pairs arranged in the width direction. For this reason, a difference in the amount of bending between the left and right in the width direction is likely to occur, and is more difficult to disappear. For this reason, cumulative skew tends to occur. Therefore, the configuration in which the feed roller pair is switched to the second state and the feed drive roller is driven to rotate forward is particularly effective in such a case.

  In addition, by providing a plurality of feed roller pairs in the width direction, it is possible to apply an appropriate feed force to both side ends of the medium to be fed in the second state. The medium to be fed can be appropriately bent within the area guided by the medium guide path. At this time, it is possible to remove the difference in the amount of bending between the left and right in the width direction. That is, by providing a plurality of pairs of feed rollers in the width direction, it is possible to more reliably remove the difference in the amount of bending between the left and right in the width direction.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the medium is fed between the feeding roller pair in the feeding direction and the conveying roller pair and in the width direction of the medium to be fed. The medium feeding device further includes a pair of detectors that detect positions in the thickness direction of the medium to be fed at positions opposed to both side edges of the medium, and the medium feeding device detects one of the pair of detectors when the other detection state is the other If it is different from the state, at least until the detection state becomes the same, the speed of the outer periphery of the feed driving roller in the second state is made faster than the speed of the outer periphery of the transport driving roller.

  According to the fifth aspect of the present invention, in addition to the same effects as any one of the first to fourth aspects, when it is determined that there is a difference between the left and right deflection amounts, The difference can be eliminated. Specifically, when one detection state of the pair of detectors is different from the other detection state, it can be determined that there is a difference between the left and right deflection amounts. In such a case, the speed of the outer periphery of the feed drive roller is made faster than the speed of the outer periphery of the transport drive roller, so that the difference in the amount of deflection on the left and right in the width direction can be eliminated.

On the other hand, when one detection state of the pair of detectors is the same as the other detection state, it can be determined that there is no difference in the amount of deflection on the left and right in the width direction. In this case, since there is no difference in the amount of bending in the left and right directions in the width direction, the outer peripheral speed of the feed drive roller can be made the same as the outer peripheral speed of the transport drive roller.
Here, “making the speed of the outer periphery of the feed driving roller the same as the speed of the outer periphery of the transport driving roller” means making the speed substantially the same as long as an error is allowed.
Energy consumption can be reduced as compared with the case where the outer peripheral speed of the feed driving roller is higher than the outer peripheral speed of the transport driving roller. That is, waste of energy consumption can be eliminated.

A recording apparatus according to a sixth 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 comprises the medium feeding device according to any one of the first to fifth aspects, and the recording medium is the medium to be fed. And
According to a sixth aspect of the present invention, the medium feeding means includes the medium feeding device according to any one of the first to fifth aspects. Therefore, in the recording apparatus, it is possible to obtain the same function and effect as in any one of the first to fifth 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 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 discharge state in the case of the skew removal which concerns on this invention. 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. The side view which shows the discharge state in the case of the skew removal of other Embodiment 1. FIG. The side view which shows the outline inside the recording device in a prior art.

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.
A plurality of intermediate drive rollers 50 and second assist rollers 51 constituting the feed roller pair 96 are provided in the width direction X. This is because a sufficient feeding force is applied to the paper in the side-view U-shaped path, and the paper P is reliably sent 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).

Next, the skew removal operation will be described.
FIG. 6 is a side view showing an initial biting state during skew removal according to the present invention.
As shown in FIG. 6, 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.

Accordingly, as described above, the leading edge of the preceding paper P1 is nipped by the conveyance roller pair 71. 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. 7 is a side view showing a discharge state during skew removal according to the present invention.
As shown in FIG. 7, the control unit 90 stops the feeding motor 91 and stops the intermediate driving roller 50 from the state of FIG. 6. 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 sheet P1 is inclined with respect to the nip line in the state shown in FIG. 6, one end side in the width direction X of the sheet P1 is greatly bent as shown by a solid line in FIG. 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 leading edge of the paper in the state shown in FIG.
If the sheet P1 is not inclined with respect to the nip line in the state shown in FIG. 6, the one end side and the other end side in the sheet width direction X in FIG.

FIG. 8 is a side view showing a cueing state at the time of skew removal according to the present invention.
As shown in FIG. 8, from the state of FIG. 7, 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, the difference 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 has not yet disappeared.
Here, as described in the prior 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 transport roller pair 71 and the transport amount on the other end side. There may be a difference between
Therefore, in order to eliminate the difference between the deflection amount on the one end side and the deflection amount on the other end side, the following operation is executed.

FIG. 9 is a side view showing a normal rotation operation after skew removal according to the present invention.
As shown in FIG. 9, the controller 90 first moves the second assist roller 51 away from the intermediate drive roller 50 by the assist separation mechanism 4 from the state of FIG. 8.
Here, the assist separation mechanism 4 is configured to be able to switch between a first state in which the second assist roller 51 approaches the intermediate drive roller 50 and a separated second state. For example, it is possible to switch between the first state and the second state by providing a cam as in the above-described swing mechanism 43.

  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. In other words, the sheet P1 can be made to follow the shape of the U-shaped outer sheet guide portion 11 to have a predetermined deflection amount.

Further, it is possible to 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 timing for rotating the intermediate drive roller in the clockwise direction may be a timing for starting the pickup of a subsequent sheet described later.
That is, during conveyance, the feed force may be generated by the transport roller pair 71 and the feed roller pair 96, or the feed force may be generated only by the transport roller pair 71.

  Further, when the paper P1 is cued, 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. That is, after the skew is removed, the conveyance drive roller 72 is driven to rotate forward, and immediately after the leading edge of the paper P1 is nipped by the conveyance roller pair 71, the second assist roller 51 is 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 sheet 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.

FIG. 10 is a side view showing how the subsequent sheet is picked up in the present invention.
As shown in FIG. 10, after the preceding sheet P1 is conveyed to the recording unit 80, the sheet 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.
In addition, 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 an intermediate driving roller 50 as a feeding driving roller that is driven by power, and a second assist roller 51 as a feeding driven roller that is driven to rotate. , A feed roller pair 96 that feeds the paper P to the downstream side in the feed direction, a transport drive roller 72 that is disposed downstream of the feed roller pair 96 in the feed direction, and that is driven by power, and a transport driven roller 73 that is driven to rotate. And a conveyance roller pair 71 that conveys the paper P sent by the feed roller pair 96 to the downstream side in the feed direction, and a medium guide path portion that guides the fed paper P from the feed roller pair 96 to the conveyance roller pair 71. The U-shaped outer sheet guide part 11 and the inner sheet guide part 12, the intermediate driving roller 50 of the feed roller pair 96, and the second An assist separation mechanism 4 as a switching unit that switches the stroller 51 relative to and away from the first state in which the intermediate drive roller 50 and the second assist roller 51 approach each other and the second state in which they are separated from each other; When the intermediate drive roller 50 of the pair of feed rollers 96 in the first state is driven to rotate forward to feed the paper P downstream in the feed direction, the feed unit 3 feeds the paper P. The posture of the leading edge, which is the downstream end in the direction, is made to follow the line direction (X) formed by the nip line, which is a circumscribed portion of the conveying roller pair 71, the conveying driving roller 72 is driven to rotate forward, and the leading end side of the paper P is conveyed to the conveying roller. The feed roller pair 96 is switched to the second state while being sandwiched between the pair 71, and the intermediate drive roller 50 is driven to rotate forward so that the paper P follows the U-shaped outer paper guide portion 11. And wherein the Rukoto.

  In the present embodiment, the feeding unit 3 drives the transport driving roller 72 to rotate forward so that the leading edge of the paper P is sandwiched between the transport roller pair 71, and then drives the transport driving roller 72 and the intermediate drive roller 50 to rotate forward. In this configuration, the sheet P is fed downstream in the feeding direction, and the outer peripheral speed V1 of the intermediate driving roller 50 at this time is faster than the outer peripheral speed V2 of the transport driving roller 72.

Furthermore, in the present embodiment, the U-shaped outer paper guide unit 11 and the inner paper guide unit 12 have a section R that is curved in side view.
In the present embodiment, a plurality of feed roller pairs 96 are arranged in the width direction X of the paper P.
The printer 1 that is a recording apparatus of the present embodiment is configured to feed a sheet P, which is an example of a recording medium, as a medium feeding unit that feeds the sheet P downstream in the feeding direction, and the sheet P sent by the feeding unit 3. And a recording unit 80 for recording by the recording head 82.
[Other embodiment 1]

FIG. 11 is a side view showing a discharge state during skew removal according to another embodiment 1.
As illustrated in FIG. 11, the printer 100 according to the other embodiment 1 includes a posture detector 101 a that detects a posture when the paper P <b> 1 is bent between the feed roller pair 96 and the transport roller pair 71 in the feed direction Y. , 101b. Specifically, it is provided to detect whether or not a certain amount of deflection has been exceeded. That is, the posture detectors 101a and 101b are provided so that the position of the paper P in the thickness direction Z of the paper P can be detected. In addition, a pair of posture detectors 101 a and 101 b are provided in the width direction X. Specifically, a pair is provided at positions facing one end side and the other end side in the width direction X of the paper P1.

The posture detectors 101a and 101b include lever portions 102a and 102b and detection sensor portions 104a and 104b. The lever portions 102a and 102b are provided so as to swing around the lever shafts 103a and 103b. A force acts so as to rotate clockwise in the figure by its own weight.
Of course, it may be biased clockwise by biasing means such as a spring.
The other members are the same as those in the above-described embodiment, so the same reference numerals are used and the description thereof is omitted.

One end of each of the lever portions 102a and 102b is provided so as to protrude into the guide path and come into contact with the paper P1. On the other hand, the other ends of the lever portions 102a and 102b are configured to block light by being positioned between a light emitting portion and a light receiving portion (not shown) of the detection sensor portions 104a and 104b. The other end of the lever portions 102a and 102b is configured to allow light to pass through when the other end is removed from between the light emitting portion and the light receiving portion. The posture detectors 101a and 101b are turned on when the other ends of the lever portions 102a and 102b are separated from the light emitting portion and the light receiving portion, and the other ends of the lever portions 102a and 102b are connected to the light emitting portion. It is configured to be in an OFF state when positioned between the light receiving unit.
Of course, the ON-OFF may be reversed.

In the discharging operation (see FIG. 7) during skew removal as in the above-described embodiment, one end side (P1 indicated by a solid line in FIG. 11) of the paper P1 in the width direction is greatly bent. Accordingly, the lever portion 102a comes into contact with the one end side and rotates the lever portion 102a counterclockwise. As a result, the attitude detector 101a on the one end side is turned on.
On the other hand, the other end side in the width direction X of the paper P1 (P1 indicated by a chain line in FIG. 11) is only slightly bent and does not come into contact with the lever portion 102b on the other end side. Therefore, the posture detector 101b on the other end side remains in the OFF state.

In this case, cueing (see FIG. 8) is executed in the same manner as in the above-described embodiment. Thereafter, the forward rotation operation (see FIG. 9) is executed. Then, when the posture detector 101a on the other end side is switched to the ON state, the forward drive of the intermediate drive roller 50 is stopped.
Thereafter, recording is performed by the recording unit 80 while the sheet P1 is conveyed by the conveying roller pair 71 as described above.

  Further, in the discharging operation at the time of skew removal, there may be a case where there is no difference between the deflection amount on one end side in the width direction X of the paper P1 and the deflection amount on the other end side in the width direction X of the paper P1. That is, the leading end of the paper P1 is not inclined with respect to the nip line, and the bending method on the one end side and the bending method on the other end side are the same. At this time, the ON / OFF state of the posture detector 101a on the one end side is the same as the ON / OFF state of the posture detector 101b on the other end side.

  In this case, there is no possibility that a difference occurs between the conveyance amount on the one end side of the conveyance roller pair 71 and the conveyance amount on the other end side. Therefore, the forward rotation operation (see FIG. 9) need not be executed. That is, the forward rotation operation (see FIG. 9) can be omitted. In the second state, the sheet can be transported with the speed of the intermediate drive roller 50 and the speed of the transport drive roller 72 being substantially the same. As a result, energy consumption can be reduced by the omitted amount.

In addition, the time from the pick-up of the paper P to the start of recording is shortened as compared with the case where the transport roller pair 71 is stopped and the intermediate driving roller 50 is driven to rotate forward at the time of cueing. Can do. In addition, the number of recording sheets P per unit time can be increased. That is, the throughput can be shortened.
Further, although the posture detectors 101a and 101b are provided on the upper side (recording head side) of the paper P, it is needless to say that the posture detectors 101a and 101b may be provided on the lower side (medium support unit side). In such a case, similar effects can be obtained.

  As in the above-described embodiment, 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. . Specifically, the second assist roller 51 is moved away from the intermediate drive roller 50 to have a relationship of “the outer periphery speed V1 of the intermediate drive roller 50> the outer periphery speed V2 of the transport drive roller 72”. 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.

  In another exemplary embodiment, the feeding unit 3 of the printer 100 is located between the feeding roller pair 96 and the transporting roller pair 71 in the feeding direction Y, and opposed to both side edges of the paper P in the width direction X of the paper P. Are further provided with detection sensor units 101a and 101b, which are a pair of detectors that detect the position of the paper P in the thickness direction Z, and the feed unit 3 has one of the detection states of the pair of detection sensor units 101a and 101b. When it is different from the other detection state, the speed of the outer periphery of the intermediate drive roller 50 in the second state is made faster than the speed of the outer periphery of the transport drive roller 72 at least until the detection state becomes the same. To do.

When one detection state of the pair of detection sensor units is the same as the other detection state, it is desirable that the outer peripheral speed of the intermediate driving roller 50 is the same as the outer peripheral speed of the transport driving roller 72. This is because it is not necessary to bend the paper P. This is because the influence of back tension can be minimized.
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 substrate unit, 3 feeding unit, 4 assist separation mechanism, 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,
51 second assist roller, 52 third assist roller, 60 paper leading edge regulating rib,
70 transport unit, 71 transport roller pair, 72 transport drive roller,
73 Conveyor 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,
100 (other embodiment 1) printer, 101a (at one end) attitude detector,
101b (on the other end side) attitude detector, 102a (on one end side) lever part,
102b (on the other end side) lever part, 103a (on one end side) lever shaft,
103b lever shaft (on the other end side), 104a detection sensor section on the one end side,
104b (on the other end) detection sensor section, 200 (prior art) recording device,
201 Feeder, 202 Guide Route, 203 Pickup Roller,
204 retard roller, 205 feed roller pair, 206 feed drive roller,
207 feed follower roller, 208 transport roller pair, 209 recording unit,
210 One end side in the width direction of the sheet, 211 The other end side in the width direction of the sheet, N nip point,
P paper, P1 preceding paper, P2 following paper, R curved section, X width direction,
Y feed direction, Z (paper) thickness direction

Claims (6)

A feed driving roller that is driven by power, a feed driven roller that is driven to rotate, and a feed roller pair that sends the medium to be sent downstream in the feed direction;
The feed roller pair is disposed on the downstream side in the feed direction, and has a transport drive roller that is driven by power, and a transport driven roller that is driven to rotate, and the medium to be fed fed by the feed roller pair is downstream 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 feed roller pair are relatively moved toward and away from each other, and a first state in which the feed drive roller and the feed driven roller are close to each other and a second state in which the feed drive roller and the feed driven roller are separated from each other A medium feeding device comprising switching means for switching ,
A position in the thickness direction of the medium to be fed is detected between the pair of feed rollers in the feed direction and the pair of transport rollers and at a position facing both side ends of the medium to be fed in the width direction of the medium to be fed. A pair of detectors,
In the medium feeding device, when one detection state of the pair of detectors is different from the other detection state, at least the speed of the outer periphery of the feed driving roller in the second state until the detection state becomes the same. Is made faster than the speed of the outer periphery of the conveyance drive roller . 2. The medium feeding device according to claim 1, wherein the feeding roller pair is switched to the second state in a state in which the feeding driving roller is driven to rotate forward and the leading end side of the medium to be fed is sandwiched between the feeding roller pair. The transport drive roller and the feed drive roller are normally driven to feed the medium to be fed to the downstream side in the feed direction, and the speed of the outer periphery of the feed drive roller at this time is the outer circumference of the transport drive roller. Media feeder which is faster than the speed of the media. A feed driving roller that is driven by power, a feed driven roller that is driven to rotate, and a feed roller pair that sends the medium to be sent downstream in the feed direction;
The feed roller pair is disposed on the downstream side in the feed direction, and has a transport drive roller that is driven by power, and a transport driven roller that is driven to rotate, and the medium to be fed fed by the feed roller pair is downstream 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 feed roller pair are relatively moved toward and away from each other, and a first state in which the feed drive roller and the feed driven roller are close to each other and a second state in which the feed drive roller and the feed driven roller are separated from each other A medium feeding device comprising switching means for switching,
The medium feeding device is configured such that when the feeding drive roller of the pair of feeding rollers in the first state is driven to rotate forward and the medium to be fed is sent to the downstream side in the feeding direction, the posture of the tip that is the downstream end in the feeding direction of the medium to be fed In accordance with the line direction formed by the circumscribed portion of the transport roller pair,
In a state where the transport drive 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 feed roller pair is switched to the second state, and the feed drive roller is driven to rotate forward. The medium is moved along the medium guide path, and the transport drive roller and the feed drive roller are driven to rotate forward to feed the medium to be fed to the downstream side in the feed direction, and the outer periphery of the feed drive roller at this time Is a medium feeding device that is faster than the outer peripheral speed of the transport drive roller . 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 apparatus according to any one of claims 1 to 4, wherein the feed roller pair, the medium feeding device is configured to have a plurality of arranged in the width direction of the feed medium. 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 5, and the recording medium is the recording medium.

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