JP2018167979A - Sheet carrying device - Google Patents

Abstract

To separate a double-fed sheet by a separation wall, and to suppress idling of a roller to a sheet even when a high resistance part, which applies carrying resistance larger than carrying resistance applied by the separation wall to a sheet, exists in a carrying path.SOLUTION: A printer 1 includes a paper feed tray 10, a roller 11 for feeding a sheet 100, an arm 12 for supporting the roller 11, a separation wall 10w, a carrying path R, and a pressing force increase mechanism for increasing a pressing force of the roller 11 to the sheet 100. Related to one of the sheet 100, the pressing force increase mechanism increases the pressing force of the roller 11 to the sheet 100 after a front end of the sheet 100 whose feeding has been started by the roller 11 reaches the separation wall 10w and the sheet 100 starts to separate from the other sheets 100 to the time where the front end of the sheet 100 fed by the rotation of the roller 11 passes a high resistance part 20g1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sheet conveying apparatus that conveys a sheet such as a sheet.

  In Patent Document 1, a first paper feed roller (roller) supported at the tip of a swingable arm is rotated while being brought into contact with the surface of a sheet stored in a paper feed tray, thereby supplying the sheet. The technology to send is shown.

  In the technique described in Japanese Patent Application Laid-Open No. H10-228707, the arm is between a full load state in which the maximum amount of sheets are stacked on the paper feed tray and a state immediately before empty loading in which the minimum amount of sheets are stacked on the paper feed tray. And the upstream angle (contact angle) in the feeding direction between the sheet and the sheet stored in the sheet feeding tray changes. Specifically, the contact angle increases as the amount of sheets stacked on the paper feed tray decreases. As the contact angle increases, the pressing force of the roller against the sheet increases. When the feeding of the sheet is started, if the pressing force of the roller against the sheet is large, double feeding (a phenomenon in which a plurality of sheets are conveyed in a stacked state) is likely to occur.

  On the other hand, Patent Document 2 discloses a technique for changing the pressing force of the roller against the sheet by changing the position of the swing shaft of the arm. If this technique is used, the pressing force of the roller against the sheet can be made constant by changing the position of the swing shaft of the arm in accordance with the amount of sheets stacked on the sheet feed tray. The setting of the pressing force of the roller to the sheet is such that the pressing force (the pressing force is large enough to separate the sheets fed double by the inclined separation surface (separation wall) provided downstream of the roller in the feeding direction. If the sheet is too large, it is not possible to separate the double-fed sheets), and the pressing force is such that the roller does not idle with respect to the sheet when the sheet passes the inclined separation surface. As a result, it is possible to suppress the occurrence of double feeding during sheet feeding as described above.

JP 2003-12171 A Japanese Patent No. 384099

  However, a sheet that is separated and conveyed from the sheet that has been multi-fed on the inclined separation surface (a sheet that contacts the roller) is, for example, a portion in the conveyance path where the conveyance resistance to the sheet is greater than the conveyance resistance on the inclined separation surface Is present, the roller may idle with respect to the sheet due to the conveyance resistance, and a conveyance failure of the sheet may occur. To prevent this sheet conveyance failure, set the pressing force so that the sheet can be conveyed even if a high conveyance resistance in the conveyance path is applied, and start feeding the sheet. However, there is a problem that the material is conveyed without being separated on the inclined separation surface.

  Therefore, an object of the present invention is to separate sheets that are multi-fed by a separation wall, and a high resistance portion that imparts a conveyance resistance to the sheet that is greater than the conveyance resistance imparted by the separation wall to the conveyance path. To provide a sheet conveying apparatus capable of suppressing idling of a roller with respect to a sheet even if it exists.

  The sheet conveying apparatus of the present invention is capable of rotating around a storage unit that can stack and store a plurality of sheets, and a rotation axis that is parallel to the sheet stored in the storage unit, and is stored in the storage unit. A roller for feeding the sheet by rotating about the rotation axis while being pressed against the surface of the sheet while being in contact with the surface of the sheet, and a first roller that supports the roller rotatably and is parallel to the rotation axis An arm that can be swung around a swinging shaft, and a separation wall that separates the sheet that contacts the roller from other sheets by imparting conveyance resistance to the sheet stacked and stored in the storage unit And a conveyance path having a high resistance portion that is provided downstream of the separation wall and imparts a conveyance resistance larger than the conveyance resistance imparted by the separation wall to the sheet, and one sheet is fed by the roller. After the leading edge of the sheet that has started to reach the separation wall and the sheet and the other sheets start to separate, the leading edge of the sheet fed by the rotation of the roller is the high resistance portion. And a pressing force increasing mechanism that increases the pressing force of the roller against the sheet until the sheet passes.

  According to this, after the leading edge of the sheet reaches the separation wall and the sheet starts to separate from the other sheet and passes through the high resistance portion, the pressing force increasing mechanism causes the roller against the sheet. The pressing force increases. For this reason, even if a large conveyance resistance is applied to the sheet passing through the conveyance path by the high resistance portion, it is possible to suppress idling of the roller with respect to the sheet. Therefore, it is possible to smoothly pass the sheet through the conveyance path. In addition, when the sheet feeding is started, the pressing force of the roller against the sheet can be set to a relatively small pressing force capable of separating the sheets that are multi-fed by the separation wall. For this reason, it becomes possible to suppress the double feeding of the sheet by the separation wall. Furthermore, since the pressing force of the roller against the sheet is increased during the conveyance of the sheet (while the roller is rotating), it is possible to effectively suppress the double feeding of the sheet.

  In the present invention, the arm is configured to be bendable about a second rocking shaft parallel to the first rocking shaft located between the roller and the first rocking shaft. A first arm extending from one swing shaft to the second swing shaft, and extending from the second swing shaft to the roller, with respect to the first arm about the second swing shaft A second arm capable of swinging, and the pressing force increasing mechanism is configured such that when a sheet starts to be fed by the roller, the sheet comes into contact with the roller and the second arm. The contact angle of the roller that forms an acute angle is the sheet fed by the rotation of the roller after the leading edge of the sheet reaches the separation wall and the sheet starts to separate from the other sheet. Increases until the tip of the wire passes through the high resistance part In so that it is preferable for oscillating the first arm. Accordingly, it is possible to increase the pressing force of the roller against the sheet only by swinging the first arm.

  In the present invention, it is preferable that the apparatus further includes a sensor that detects that the contact angle has become a predetermined angle when a sheet is fed by the roller. Thereby, the contact angle of the roller when starting the sheet feeding by the roller can be set to a predetermined angle every time. For this reason, the conveyance force of the sheet by the roller at the start of feeding becomes constant, and it becomes possible to suppress double feeding and idle feeding.

  In the present invention, the pressing force increasing mechanism includes a drive mechanism for swinging the first arm and an angle detection means for detecting a rotation angle of the first arm, and the drive The mechanism preferably swings the first arm based on the rotation angle detected by the angle detection means. As a result, the swing control of the first arm can be performed with a simple configuration.

  Further, in the present invention, the arm has an arm body extending from the roller to the first swing shaft, and the pressing force increasing mechanism is configured such that the leading end of the sheet has the tip of the sheet. After the separation wall is reached and the sheet and the other sheets start to separate, the roller is fed by the rotation of the roller until the leading edge of the sheet passes through the high resistance portion. It is preferable to increase the force for swinging the arm in the direction in which the pressing force applied to the sheet increases. Accordingly, it is possible to increase the pressing force of the roller against the sheet only by increasing the force for swinging the arm.

  In the present invention, the pressing force increasing mechanism may include a support plate that supports the sheet stored in the storage portion, and at least a facing region of the support plate that faces the roller in a direction facing the roller. A support plate elevating mechanism that can be moved, and the support plate elevating mechanism contacts the roller when the sheet starts to be fed by the roller with respect to the sheet and the arm. The contact angle of the roller that forms an acute angle is determined after the leading edge of the sheet reaches the separation wall and separation of the sheet from other sheets begins and the sheet is fed by the rotation of the roller. It is preferable to move the facing region away from the roller so that the leading edge of the sheet increases before passing the high resistance portion. Accordingly, it is possible to increase the pressing force of the roller against the sheet only by moving the opposed region of the support plate away from the roller.

  In the present invention, it is preferable that the conveyance path includes a curved path as the high resistance portion. As a result, even if the conveyance path includes a curved path having a large conveyance resistance, the sheet can be passed smoothly. Furthermore, even if the curvature radius of the curved path is reduced and the conveyance resistance to the sheet is increased as the apparatus itself is thinned, the sheet can be passed smoothly.

  In the present invention, the pressing force increasing mechanism includes a storage unit that stores data relating to a change in conveyance resistance with respect to a change in the position of the sheet in the conveyance path, and a conveyance amount that detects a conveyance amount of the sheet conveyed by the roller. It is preferable that the pressing force of the roller against the sheet is increased based on the data and the conveyance amount by the conveyance amount detection unit. Accordingly, it is possible to determine the timing of increase in the pressing force of the roller against the sheet without providing a sensor for detecting the sheet conveyance position in the conveyance path.

  In the present invention, the conveyance path is provided with a sensor for detecting the leading edge of the sheet at a position upstream of the high resistance portion and downstream of the separation wall, and the pressing force increasing mechanism is It is preferable to increase the pressing force of the roller against the sheet when the leading edge of the sheet is detected by the sensor. Thus, the pressing force of the roller against the sheet can be increased before the leading edge of the sheet reaches the high resistance portion. For this reason, it becomes possible to suppress idling of the roller with respect to the sheet.

  According to the sheet conveying device of the present invention, after the leading edge of the sheet reaches the separation wall and the sheet and the other sheet start to be separated and before passing the high resistance portion, the pressing force increasing mechanism The pressing force of the roller against the sheet increases. For this reason, even if a large conveyance resistance is applied to the sheet passing through the conveyance path by the high resistance portion, it is possible to suppress idling of the roller with respect to the sheet. Therefore, it is possible to smoothly pass the sheet through the conveyance path. In addition, when the sheet feeding is started, the pressing force of the roller against the sheet can be set to a relatively small pressing force capable of separating the sheets that are multi-fed by the separation wall. For this reason, it becomes possible to suppress the double feeding of the sheet by the separation wall. Furthermore, since the pressing force of the roller against the sheet is increased during the conveyance of the sheet (while the roller is rotating), it is possible to effectively suppress the double feeding of the sheet.

1 is a schematic side view showing an internal structure of a printer according to a first embodiment of the present invention. It is a block diagram of the control apparatus shown in FIG. 2A and 2B are diagrams illustrating a paper feed tray, an arm, and a periphery thereof shown in FIG. 1, and FIG. 2A is a diagram illustrating a state in which the arm is disposed at an initial position, and FIG. It is a figure which shows the condition which became larger than the time of sending. FIG. 7 is a diagram illustrating a paper feed tray, an arm, and a periphery thereof of a printer according to a second embodiment of the present invention, wherein (a) is a diagram illustrating a state in which the arm is disposed at an initial position, and (b) is a roller. It is a figure which shows the condition which touched the paper. FIG. 10 is a diagram illustrating a paper feed tray, an arm, and a periphery thereof of a printer according to a third embodiment of the present invention, where (a) is a diagram illustrating a situation when a contact angle of the roller is θ, and (b) is a diagram illustrating a roller. It is a figure which shows the condition when the contact angle of (theta) is (theta) 1. It is a block diagram of the control apparatus shown in FIG.

  The printer according to the first embodiment of the present invention will be described below. As shown in FIG. 1, the printer (sheet transport device) 1 includes a paper feed tray (accommodating portion) 10 having a substantially box shape capable of stacking and accommodating a plurality of sheets (sheets) 100, and a paper feed tray 10. A transport unit 20 that transports the uppermost sheet 100 among the plurality of stored sheets 100 along the transport path R, a recording unit 30 that records on the sheet 100 transported by the transport unit 20, and a recording unit 30 It includes an opposing platen 40, a paper discharge tray 50 that receives the paper 100 conveyed by the conveyance unit 20, and a control device 60 that controls the conveyance unit 20, the recording unit 30, and the like.

  The transport unit 20 is disposed upstream of the transport path R with respect to the roller 11 disposed so as to be in contact with the uppermost sheet 100 among the plurality of sheets 100 accommodated in the paper feed tray 10 and the recording unit 30. A pair of rollers 21, a pair of rollers 22 disposed downstream of the conveyance path R with respect to the recording unit 30, and a guide plate 20 g that defines the conveyance path R. Note that the distance along the conveyance path R between the roller 11 and the roller pair 21 is equal to or less than the length of the paper 100 fed from the paper feed tray 10 in the feeding direction. That is, the paper 11 is fed from the paper feed tray 10 to the roller pair 21 by the roller 11. As shown in FIG. 1, the guide plate 20g is provided continuously with a separation wall 10w, which will be described later, and constitutes a curved path R1 that curves to the right as it goes from below to above in the transport path R. A high resistance portion 20g1. The curved path R1 is a high resistance portion that gives a large transport resistance to the paper 100 passing through the transport path R.

  The guide plate 20g is provided with a paper sensor 20g2 that detects the leading edge of the paper 100 conveyed by the roller 11. The paper sensor 20g2 is disposed at a position upstream of the high resistance portion 20g1 and downstream of a separation wall 10w described later in the feeding direction. When the paper sensor 20 g 2 detects the leading edge of the paper 100, the paper sensor 20 g 2 outputs a detection signal to the control device 60. With such a paper sensor 20g2, it is possible to detect that the paper 100 is in a position immediately before reaching the high resistance portion 20g1.

  The roller 11 has a rotation shaft 11x parallel to the paper 100 accommodated in the paper feed tray 10, and is pressed against the surface of the uppermost paper 100 among the plurality of papers 100 accommodated in the paper feed tray 10. To do. The roller 11 feeds the paper 100 in the feeding direction by rotating around the rotation shaft 11x while being in contact with the surface of the paper 100.

  The paper feed tray 10 has a separation wall 10w. The separation wall 10w is configured as one of the four side walls of the paper feed tray 10 that is disposed downstream of the roller 11 in the feeding direction (left side in FIG. 1). The separation wall 10w contacts the paper 100 that is the furthest away from the roller 11 among the plurality of papers 100 that are double-fed by the rotation of the roller 11, and applies a conveyance resistance to the paper 100, whereby the paper that contacts the roller 11 100 has a function of separating 100 from other multi-feed paper 100. The conveyance resistance applied to the paper 100 by the separation wall 10w is smaller than the conveyance resistance due to the curved path described above. In order to realize the function, the separation wall 10w is configured, for example, by attaching a separation piece (not shown). The separation piece is, for example, a plate member made of a material having high frictional resistance (cork, rubber, etc.) or a member on which a plurality of protrusions made of resin or metal are formed.

  The rotation shaft 11x of the roller 11 is rotatably supported at the tip of the arm 12 (tip of the second arm 12b described later). The arm 12 is in a state in which the roller 11 is downstream in the feeding direction from the first swing shaft 12x1 around the first swing shaft 12x1 provided at the base end (end opposite to the tip). It can be swung while maintaining. The first swing shaft 12x1 is parallel to the rotation shaft 11x and is rotatably supported by a housing (not shown) of the printer 1. The arm 12 is configured to be bendable around a second swing shaft 12x2 parallel to the first swing shaft 12x1 positioned between the roller 11 and the first swing shaft 12x1, and the first arm 12a, a second arm 12b, and a biasing member 12c.

  The first arm 12a extends from the first swing shaft 12x1 to the second swing shaft 12x2. The second swing shaft 12x2 is rotatably supported at the end of the first arm 12a opposite to the first swing shaft 12x1. The second arm 12b extends from the second swing shaft 12x2 to the roller 11, and is rotatably supported by the second swing shaft 12x2. As a result, the second arm 12b can swing with respect to the first arm 12a about the second swing shaft 12x2.

  The biasing member 12c in the present embodiment employs a coil spring, but may be composed of other elastic members. One end of the coil spring 12c is locked to the first arm 12a, and the other end is locked to the second arm 12b. The coil spring 12c biases the first arm 12a and the second arm 12b in a direction in which a line segment connecting the first swing shaft 12x1, the second swing shaft 12x2 and the rotation shaft 11x is a straight line. For this reason, as shown in FIG. 1, when the roller 11 and the paper 100 are in contact with each other, the roller 11 exerts a predetermined pressing force on the paper 100 not only by the weight of the arm 12 but also by the urging force of the coil spring 12c. It will be in the pressed state. On the other hand, when the roller 11 is not in contact with the paper 100, the arm 12 is linearly extended by the biasing force of the coil spring 12c. The urging member 12c may not be provided. In this case, a pressing force due to the weight of the arm 12 or the like is applied to the paper 100.

  As shown in FIG. 1, the arm 12 supports gears 12g1 to 12g7. More specifically, the gears 12g1 to 12g3 are supported by the second arm 12b, and the gears 12g4 to 12g7 are supported by the first arm 12a. The gears 12g1 to 12g7 mesh with each other, the gear 12g1 is fixed to the rotation shaft 11x, the gear 12g7 meshes with the shaft 11Mx of the drive motor 11M, and the gears 12g2 to 12g6 connect the gear 12g1 and the gear 12g7. The gear 12g4 is fixed to the second swing shaft 12x2. When the drive motor 11M is driven, the gears 12g1 to 12g7 rotate, the driving force of the drive motor 11M is transmitted to the roller 11, and the roller 11 rotates.

  As shown in FIG. 1, the end of the first arm 12a on the first swing shaft 12x1 side meshes with a shaft 12Mx of a drive motor 12M (drive mechanism), and the drive of the drive motor 12M causes the first arm 12a to move. It swings around the first swing shaft 12x1. That is, the arm 12 swings. A rotary encoder 14 (see FIG. 2) for detecting the rotation angle of the first arm 12a is provided in the vicinity of the shaft 12Mx of the drive motor 12M. The rotary encoder (angle detection means) 14 outputs a signal indicating the rotation angle of the first arm 12 a to the control device 60. The control device 60 controls the drive motor 12M based on the rotation angle detected by the rotary encoder 14 to swing the first arm 12a.

  The second arm 12b of the arm 12 is provided with an angle detection mechanism 13 for detecting that the contact angle of the roller 11 is a predetermined angle θ. In the present embodiment, the contact angle of the roller 11 is determined by the sheet 100 and the second arm 12b (line segment L connecting the second swing shaft 12x2 and the rotation shaft 11x) in a state where the roller 11 is in contact with the sheet 100. An acute angle. As shown in FIG. 1, the angle detection mechanism 13 has a bar member 13a and a sensor 13b. The bar member 13a is supported by the second arm 12b so as to be rotatable about a portion from the upper side from the center in the extending direction. The sensor 13b includes a detection unit 13b1 that includes a light emitting unit and a light receiving unit that receives light from the light emitting unit. As shown in FIG. 1, the bar member 13a enters between the light emitting portion and the light receiving portion of the detecting portion 13b1 when the contact angle of the roller 11 takes a predetermined angle θ. Thereby, the sensor 13 detects the bar member 13 a and outputs the detection signal to the control device 60. That is, the sensor 13 detects that the contact angle has become the predetermined angle θ.

  The control device 60 includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), an application specific integrated circuit (ASIC), and the like. 11M and the drive motor 12M) and the operation of the recording unit 30 and the like. For example, the control device 60 controls the transport unit 20 and the recording unit 30 based on a recording command transmitted from the PC, and performs a recording operation for recording an image or the like on the paper P.

  Hereinafter, the feeding operation of the paper 100 when performing the recording operation will be described with reference to FIG.

  When receiving the recording command, the control device 60 controls the drive motor 12M so that the arm 12 swings from the initial position shown in FIG. 3A to the position shown in FIG. Since the rod member 13a is rotatable with respect to the second arm 12b, the posture is maintained along the substantially vertical direction when the arm 12 is in the initial position. When the drive motor 12M is driven by the control device 60, the arm 12 swings so that the roller 11 contacts the paper 100. As shown in FIG. 1, the control device 60 stops driving the drive motor 12M at the timing when the rod member 13a is detected by the sensor 13b and the control device 60 receives a signal from the sensor 13b. Thereby, the contact angle of the roller 11 at the time of feeding becomes the predetermined angle θ. The contact angle θ at this time is such that the pressing force of the roller 11 against the paper 100 does not cause the roller 11 to idle with respect to the paper 100, and the double-fed paper 100 is separated from the paper 100 in contact with the roller 100 by the separation wall 10w. It is an angle that can be made to be. Thus, the contact angle of the roller 11 at the time of feeding is set to the predetermined angle θ.

  Next, the control device 60 drives the drive motor 11M to feed the paper 100 in the feeding direction with the roller 11. At this time, even if a plurality of paper sheets 100 are multi-feeded, the paper sheet 100 that contacts the roller 11 is separated from the other paper sheets 100 by the separation wall 10w. In this way, the conveyance of one sheet 100 separated by the separation wall 10w and contacting the roller 11 is started. Thereafter, when the leading edge of the paper 100 is detected by the paper sensor 20g2, the control device 60 is driven so that the contact angle θ1 is larger than the contact angle θ1 of the roller 11, as shown in FIG. The motor 12M is controlled. Note that the swing control of the first arm 12a at this time is executed while the paper 100 is being conveyed by the roller 11 (while the roller 11 is rotating). The control device 60 controls the drive motor 12M so that the first arm 12a swings a predetermined rotation angle clockwise around the first swing shaft 12x1. The swing control of the first arm 12a at this time is executed based on a signal indicating the rotation angle from the rotary encoder 14. By swinging the first arm 12a in this way, the second arm 12b swings counterclockwise about the second swing shaft 12x2 and the contact angle of the roller 11 changes from the predetermined angle θ to θ1. growing. As the contact angle of the roller 11 increases from the predetermined angle θ to θ1, the pressing force of the roller 11 against the paper 100 increases. As a result, even when the sheet 100 passes through the high resistance portion 20g1 constituting the curved path, even if the conveyance resistance to the sheet 100 increases, the sheet 100 before the leading edge of the sheet 100 reaches the high resistance portion 20g1. Since the pressing force of the roller 11 against the roller 11 increases, the roller 11 does not idle with respect to the paper 100, and the paper P can be smoothly conveyed even in the curved path. In the present embodiment, the driving motor 12M, the rotary encoder 14, and the control device 60 constitute a pressing force increasing mechanism that increases the pressing force of the roller 11 against the paper 100.

  Thereafter, the control device 60 controls the drive motors (not shown) of the roller pairs 21 and 22 of the transport unit 20 and the recording unit 30, so that the paper 100 is transported to the recording unit 30 and an image is formed on the paper 100. The recording is performed, and the paper 100 is discharged to the paper discharge tray 50. Thus, the recording operation is completed. In this embodiment, when feeding the paper 100, the arm 12 is swung from the initial position. However, the arm 12 is swung from a state where the roller 11 is in contact with the paper 100. Also good. In short, when the paper 100 is fed, the arm 12 may be controlled to swing so that the contact angle of the roller 11 becomes the predetermined angle θ.

  As described above, according to the printer 1 of the present embodiment, after the leading edge of one sheet 100 reaches the separation wall 10w and the sheet 100 and the other sheets 100 start to be separated from each other, the height is high. Before reaching the resistance portion 20g1, the contact angle of the roller 11 is changed from θ to θ1 by the control of the control device 60, whereby the pressing force of the roller 11 against the paper 100 increases. For this reason, even if a conveyance resistance larger than the conveyance resistance applied by the separation wall 10w to the sheet 100 passing through the conveyance path R (that is, conveyance resistance by the high resistance portion 20g1 constituting the curved path) is applied, the sheet It becomes possible to suppress idling of the roller 11 with respect to 100. Therefore, it is possible to smoothly pass the paper 100 through the transport path R. Further, when the feeding of the paper 100 is started, the pressing force of the roller 11 against the paper 100 can be set to a relatively small pressing force capable of separating the double-feed paper 100 by the separation wall 10w. It becomes. For this reason, it becomes possible to suppress double feeding of the paper 100 by the separation wall 10w.

  Further, since the contact angle of the roller 11 is changed so as to increase the pressing force of the roller 11 against the paper 100 while the roller 11 is rotating, the increase of the pressing force of the roller 11 against the paper 100 is caused to convey the paper 100. It is possible to suppress the double feeding of sheets as compared with the case where the sheet is stopped. If the conveyance of the paper 100 is stopped (that is, when the rotation of the roller 11 is stopped) and the pressing force of the roller 11 against the paper 100 is increased, the paper 100 is conveyed again. In some cases, the sheet 100 may be double fed without being separated by the separation wall 10w due to the static frictional force on the sheet 100. However, in the present embodiment, a timing at which a static friction force is not generated on the paper 100, that is, in a state where a dynamic friction force is generated on the paper 100 while the paper 100 is being transported (that is, while the roller 11 is rotating). Then, the pressing force of the roller 11 against the paper 100 is increased. For this reason, it is difficult for double feeding or the like to occur during rotation of the roller 11.

  Further, since the arm 12 has the first arm 12a and the second arm 12b, the contact angle of the roller 11 is changed from θ to θ1 only by swinging the first arm 12a, and the roller with respect to the paper 100 is changed. 11 pressing force can be increased.

  Further, when the feeding of the paper 100 by the roller 11 is started, the sensor 13b that detects that the contact angle becomes θ is provided, so that the roller 11 can start feeding the paper 100. The contact angle of the roller 11 can be set to the predetermined angle θ every time. For this reason, the conveyance force of the paper 100 by the roller 11 at the start of feeding becomes constant, and it becomes possible to suppress double feeding and idle feeding.

  By having the driving motor 12M and the rotary encoder 14 as a pressing force increasing mechanism for increasing the pressing force on the paper 100, the swing control of the first arm 12a can be performed with a simple configuration.

  Even if the conveyance path R has the high resistance portion 20g1 that forms a curved path that gives the sheet 100 a conveyance resistance larger than the conveyance resistance imparted by the separation wall 10w, the contact angle of the roller 11 is changed. By increasing the pressing force of the roller 11 against the paper 100, the paper 100 can be smoothly passed through the transport path R. Even when the curvature radius of the curved path is reduced and the conveyance resistance to the paper is increased as the printer 1 itself is thinned, the paper 100 can be smoothly passed as described above.

  Next, a printer 201 according to the second embodiment of the present invention will be described below with reference to FIG. The printer 201 in the present embodiment also has substantially the same configuration as the printer 1 described above, but the configuration of the arm 212 is slightly different, and a sensor 220 that detects the amount of the paper 100 in the paper feed tray 10 is provided. ing. In addition, about the thing similar to 1st Embodiment, it shows with the same code | symbol and abbreviate | omits description.

  As shown in FIG. 4, the arm 212 has one arm body 213 extending linearly from the first swing shaft 12 x 1 to the roller 11, and can be bent like the arm 12 described above. is not. The arm main body 213 supports the rotation shaft 11x of the roller 11 at the tip thereof so as to be rotatable. The arm body 213 is in a state in which the roller 11 is located downstream of the first swing shaft 12x1 with respect to the first swing shaft 12x1 around the first swing shaft 12x1 provided at the base end (end opposite to the tip). Can be swung while maintaining the above.

  The arm 212 also supports the seven gears 12g1 to 12g7 in the same manner as the arm 12 described above. When the drive motor 11M is driven, the gears 12g1 to 12g7 rotate, the driving force of the drive motor 11M is transmitted to the roller 11, and the roller 11 rotates. Further, as shown in FIG. 4, the end of the arm main body 213 on the first swing shaft 12x1 side meshes with the shaft 12Mx of the drive motor 12M, and the arm main body 213 is first swung by the drive motor 12M. It swings around the axis 12x1. That is, the arm 212 swings. A rotary encoder 14 for detecting the rotation angle of the arm body 213 is provided in the vicinity of the shaft 12Mx of the drive motor 12M, as described above. The control device 60 swings the arm main body 213 based on the amount of paper detected by the sensor 220 and the rotation angle detected by the rotary encoder 14.

  Hereinafter, with reference to FIG. 4, the feeding operation of the paper 100 when performing the recording operation will be described below.

  Also in the feeding operation in the present embodiment, when receiving a recording command, the control device 60 causes the arm 212 to swing from the initial position shown in FIG. 4A to the position shown in FIG. 4B. In addition, the drive motor 12M is controlled. At this time, the control device 60 swings the arm main body 213 based on the amount of paper detected by the sensor 220 and the rotation angle detected by the rotary encoder 14 to bring the roller 11 and the paper 100 into contact with each other. . At this time, the paper 100 is pressed by the roller 11 with a predetermined pressing force. The pressing force at this time is the same pressing force as when the contact angle of the roller 11 in the above-described embodiment is θ. That is, the pressing force of the roller 11 against the paper 100 enables the roller 11 to be separated from the paper 100 in contact with the roller 100 by the separation wall 10 w without causing the roller 11 to idle with respect to the paper 100. It is a pressing force.

  Next, the control device 60 drives the drive motor 11M to feed the paper 100 in the feeding direction with the roller 11. At this time, even if a plurality of paper sheets 100 are multi-feeded, the paper sheet 100 that contacts the roller 11 is separated from the other paper sheets 100 by the separation wall 10w. In this way, the conveyance of one sheet 100 separated by the separation wall 10w and contacting the roller 11 is started. Thereafter, when the leading edge of the paper 100 is detected by the paper sensor 20g2, as shown in FIG. 4B, the arm body 213 is rotated counterclockwise (that is, the pressing force applied to the paper 100 by the roller 11 increases). The driving motor 12M is controlled so that the force to be swung in the direction of movement increases. As a result, the pressing force of the roller 11 against the paper 100 increases. As a result, when the sheet 100 passes through the high-resistance portion 20g1 constituting the curved path R1, even if the conveyance resistance to the sheet 100 increases, the sheet 100 is moved before the sheet 100 reaches the high-resistance portion 20g1. Since the pressing force of the roller 11 is increased, the roller 11 does not idle with respect to the paper 100, and the paper P can be smoothly conveyed also in the curved path R1. The swing control of the arm main body 213 at this time is also executed while the paper 100 is being conveyed by the roller 11 (while the roller 11 is rotating). For this reason, the effect similar to 1st Embodiment can be acquired. In the present embodiment, the driving motor 12M, the rotary encoder 14, and the control device 60 constitute a pressing force increasing mechanism that increases the pressing force of the roller 11 against the paper 100.

  Thereafter, the control device 60 controls the drive motors (not shown) of the roller pairs 21 and 22 of the transport unit 20 and the recording unit 30, so that the paper 100 is transported to the recording unit 30 and an image is recorded on the paper 100. Then, the paper 100 is discharged to the paper discharge tray 50. Thus, the recording operation is completed.

  As described above, also in the printer 201 of the present embodiment, after the leading edge of one sheet 100 reaches the separation wall 10w and the sheet 100 and the other sheets 100 start to be separated, the height is high. Before reaching the resistance portion 20g1, the pressing force of the roller 11 against the paper 100 increases under the control of the control device 60. For this reason, even if a conveyance resistance larger than the conveyance resistance imparted by the separation wall 10w to the sheet 100 passing through the conveyance path R (that is, conveyance resistance by the high resistance portion 20g1 constituting the curved path R1) is given, It is possible to suppress idling of the roller 11 with respect to the paper 100. Therefore, it is possible to smoothly pass the paper 100 through the transport path R. Further, when the feeding of the paper 100 is started, the pressing force of the roller 11 against the paper 100 can be set to a relatively small pressing force capable of separating the double-feed paper 100 by the separation wall 10w. It becomes. For this reason, it becomes possible to suppress double feeding of the paper 100 by the separation wall 10w. Note that the same effect can be obtained in the same configuration as in the first embodiment.

  Next, a printer 301 according to the third embodiment of the present invention will be described below with reference to FIGS. 5 and 6. The printer 301 in the present embodiment has substantially the same configuration as the printer 201 in the second embodiment, but the support plate 330 and the support plate lifting mechanism 340 for moving the support plate 330 up and down in the paper feed tray 10. Is provided. The printer 301 is not provided with the drive motor 12M. Therefore, the arm 212 is disposed so as to be swingable about the first swing shaft 12 x 1 and is in contact with either the paper 100 or the support plate 330. In addition, about the thing similar to 2nd Embodiment, it shows with the same code | symbol and abbreviate | omits description.

  As shown in FIG. 5, the support plate 330 is a plate-like member that supports a plurality of sheets 100 stored in the sheet feed tray 10 from below. The support plate 330 in the present embodiment is configured to be able to support the entire sheet 100 from below. The support plate raising / lowering mechanism 340 supports the support plate 330 from below and raises and lowers the support plate 330. The support plate elevating mechanism 340 may have any configuration as long as the support plate 330 can be raised and lowered, and is not particularly limited.

  The control device 360 in the present embodiment is substantially the same as the control device 60 in the first and second embodiments described above, but has a storage unit 361 as shown in FIG. The storage unit 361 stores data related to a change in conveyance resistance corresponding to a change in the position of the paper 100 in the conveyance path R. That is, in the transport path R, position data of the high resistance portion 20g1 constituting the curved path R1 having a high transport resistance applied to the paper 100 is stored. Further, a rotary encoder 314 (see FIG. 6) for detecting the rotation angle of the roller 11 is provided in the vicinity of the rotation shaft 11x of the roller 11. The rotary encoder 314 outputs a signal indicating the rotation angle of the roller 11 to the control device 360. The control device 360 derives the carry amount of the paper 100 fed by the roller 11 based on the rotation angle detected by the rotary encoder 314, and based on the data stored in the storage unit 361 and the carry amount. The pressing force increasing timing for increasing the pressing force of the roller 11 against the paper 100 is determined. In this embodiment, the pressing force increase timing is immediately before the leading edge of the paper 100 reaches the high resistance portion 20g1 constituting the curved path R1. In the present embodiment, the rotary encoder 314 and the control device 360 constitute a transport amount detection unit that detects the transport amount of the paper 100 fed by the roller 11.

  Hereinafter, the feeding operation of the paper 100 when performing the recording operation will be described with reference to FIG.

  In the feeding operation in the present embodiment, when receiving the recording command, the control device 360 supports the roller 11 so that the contact angle of the roller 11 becomes the predetermined angle θ based on the amount of the paper 100 detected by the sensor 220. The plate elevating mechanism 340 is controlled. The contact angle of the roller 11 in the present embodiment is an acute angle between the paper 100 and the arm 212 (line segment L1 connecting the first swing shaft 12x1 and the rotation shaft 11x) in a state where the roller 11 is in contact with the paper 100. The angle to make. Accordingly, as in the first embodiment, the pressing force of the roller 11 against the paper 100 is such that the roller 11 does not idle with respect to the paper 100, and the double-fed paper 100 is separated from the paper 100 that contacts the roller 100. The pressing force can be separated at 10 w.

  Next, the control device 360 drives the drive motor 11M to feed the paper 100 in the feeding direction by the roller 11. At this time, even if a plurality of paper sheets 100 are multi-feeded, the paper sheet 100 that contacts the roller 11 is separated from the other paper sheets 100 by the separation wall 10w. In this way, the conveyance of one sheet 100 separated by the separation wall 10w and contacting the roller 11 is started. Thereafter, when the control device 360 determines that the above-described pressing force increase timing determined based on the transport amount of the paper 100 and the data stored in the storage unit 361, the control device 360 controls the support plate lifting mechanism 340. Then, the support plate 330 is lowered from the position shown in FIG. 5A to the position shown in FIG. Thus, the contact angle of the roller 11 is changed from θ to θ1 larger than θ. Thus, by increasing the contact angle of the roller 11 from θ to θ1, the pressing force of the roller 11 against the paper 100 increases. As a result, as in the first embodiment described above, even when the paper 100 passes through the high resistance portion 20g1 constituting the curved path R1, even if the conveyance resistance to the paper 100 increases, the paper is applied to the high resistance portion 20g1. Since the pressing force of the roller 11 against the paper 100 increases before the leading edge of the paper 100 reaches, the roller 11 does not idle with respect to the paper 100, and the paper P can be smoothly conveyed even in the curved path. It becomes. At this time, the swing control of the arm 212 by changing the position of the support plate 330 is executed while the paper 100 is being conveyed by the roller 11 (while the roller 11 is rotating). For this reason, the effect similar to 1st Embodiment can be acquired. In the present embodiment, a pressing force increasing mechanism that increases the pressing force of the roller 11 against the paper 100 is configured by the support plate 330, the support plate lifting mechanism 340, the rotary encoder 314, and the control device 360 (including the storage unit 361). .

  Thereafter, the control device 360 controls the drive motors (not shown) of the roller pairs 21 and 22 of the transport unit 20 and the recording unit 30, so that the paper 100 is transported to the recording unit 30 and an image is recorded on the paper 100. Then, the paper 100 is discharged to the paper discharge tray 50. Thus, the recording operation is completed.

  As described above, also in the printer 301 of this embodiment, the roller 11 and the paper 100 are in contact with each other after the conveyance of the single paper 100 separated by the separation wall 10w is started. 11, the pressing force of the roller 11 against the paper 100 increases under the control of the control device 360. For this reason, even if a conveyance resistance larger than the conveyance resistance imparted by the separation wall 10w to the sheet 100 passing through the conveyance path R (that is, conveyance resistance by the high resistance portion 20g1 constituting the curved path R1) is given, It is possible to suppress idling of the roller 11 with respect to the paper 100. Therefore, it is possible to smoothly pass the paper 100 through the transport path R. Further, when the feeding of the paper 100 is started, the pressing force of the roller 11 against the paper 100 can be set to a relatively small pressing force capable of separating the double-feed paper 100 by the separation wall 10w. It becomes. For this reason, it becomes possible to suppress double feeding of the paper 100 by the separation wall 10w. Note that the same effect can be obtained in the same configuration as in the first and second embodiments described above.

  In addition, since the support plate 330 and the support plate lifting mechanism 340 that lifts and lowers the support plate 330 are provided, the roller 11 with respect to the paper 100 can be simply moved in a direction away from the roller 11 (ie, downward). It is possible to increase the pressing force.

  Further, since the rotary encoder 314 and the control device 360 (including the storage unit 361) are provided, the roller 11 for the paper 100 can be provided without providing a sensor for detecting the transport position of the paper 100 in the transport path R. It is possible to determine the timing of the increase of the pressing force.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, the timing for increasing the pressing force of the roller 11 against the paper 100 is after the leading edge of one paper 100 passes through the separation wall 10w and passes through the high resistance portion 20g1. As long as it is in contact with the roller 11 and the roller 11 is rotating. In the above-described embodiment, the pressing force of the roller 11 against the paper 100 is increased before the leading edge of the paper 100 reaches the high resistance portion 20g1, but the leading edge of the paper 100 reaches the high resistance portion 20g1 and passes therethrough. In the meantime, the pressing force of the roller 11 against the paper 100 may be increased. In this case, for example, the paper sensor 20g2 may be provided in the high resistance portion 20g1 to detect the leading edge of the paper 100. Thus, if the pressing force of the roller 11 against the paper 100 is increased while the leading edge of the paper 100 reaches and passes through the high resistance portion 20g1, the idling of the roller 11 with respect to the paper 100 can be suppressed. Thus, the paper 100 can be smoothly passed through the transport path R. Furthermore, the timing of increasing the pressing force of the roller 11 against the paper 100 is sufficient if the leading edge of one paper 100 reaches the separation wall 10w and the paper 100 and the other paper 100 start to separate. The tip does not have to pass through the separation wall 10w. In this way, even if a large conveyance resistance is applied to the sheet 100 passing through the conveyance path R by the high resistance portion 20g1 while suppressing the double feeding of the sheet 100 by the separation wall 10w, the roller 11 is caused to idle with respect to the sheet 100. It becomes possible to suppress.

  In the first embodiment described above, the bar member 13a is detected by the sensor 13b so that the contact angle of the roller 11 becomes θ. However, it is detected that the contact angle of the roller 11 becomes θ. As long as this is possible, any sensor may be used. If it is possible to detect that the contact angle of the roller 11 becomes θ with a sensor alone, the bar member 13a and the like need not be provided.

  In the conveyance path R, the high resistance portion that imparts a conveyance resistance larger than the conveyance resistance imparted by the separation wall 10w is not limited to the high resistance portion 20g1 that constitutes the curved path R1, and is provided in the conveyance path R. It may be a high resistance part (conveyance roller, registration roller, etc.).

  In the third embodiment described above, when the pressing force of the roller 11 against the paper 100 is increased, the entire support plate 330 is lowered by the support plate raising / lowering mechanism 340, but facing the roller 11 of the support plate 330. Only the region may be lowered by the support plate lifting mechanism 340. Even in this case, the pressing force of the roller 11 against the paper 100 can be increased. Further, instead of the rotary encoder 314, a sensor for detecting the rotational speed of the rotary shaft 11x may be provided. In this case, the conveyance amount of the sheet 100 may be derived based on the rotation speed from the sensor.

  In the third embodiment described above, when the pressing force of the roller 11 against the paper 100 is increased, the support plate 330 is lowered by the support plate raising / lowering mechanism 340. However, the control device 360 causes the support plate 330 to move downward. The support plate elevating mechanism 340 may be controlled so that the force in the upward direction (that is, the direction in which the pressing force applied by the roller 11 to the paper 100 increases) increases. At this time, for example, the drive motor 12M may restrict the swing of the arm 212 so that the arm 212 does not swing due to the pressing force from the support plate 330. Even in this case, the pressing force of the roller 11 against the paper 100 increases. As a result, even when the conveyance resistance to the paper 100 increases when the paper 100 passes through the portion 20g1 constituting the curved path R1, the roller 11 is pressed against the paper 100 before the paper 100 reaches the portion 20g1. Since the pressure is increased, the roller 11 does not idle with respect to the paper 100, and the paper P can be smoothly conveyed also in the curved path R1.

  Further, the arms 12 and 212 in each of the above-described embodiments can swing while maintaining the state where the roller 11 is downstream of the first swing shaft 12x1 in the feeding direction. It may be swingable while maintaining a state upstream of the swing shaft 12x1 in the feeding direction. Further, the arm 12 in the first embodiment may be swingable while maintaining the state in which the first swing shaft 12x1 is downstream of the second swing shaft 12x2 in the feeding direction. Further, the arm 12 in the first embodiment may be swingable while maintaining the state in which the rotation shaft 11x is upstream of the second swing shaft 12x2 in the feeding direction.

  The recording unit 30 may be an ink jet type, a thermal type, a laser type, or the like. The present invention is not limited to a printer, but can also be applied to a facsimile machine, a copier, a multifunction machine, and the like. The sheet conveying apparatus may not have a recording unit. The sheet is not limited to paper, and may be cloth or the like.

1 Printer (sheet transport device)
10 Paper feed tray (container)
10w Separating wall 11 Roller 11x Rotating shaft 12, 212 Arm 12a First arm 12b Second arm 12M Drive motor (drive mechanism: part of the pressing force increasing mechanism)
12x1 first swing shaft 13b sensor 14 rotary encoder (angle detection means: part of the pressing force increasing mechanism)
20g1 part (high resistance part)
60, 360 control device (part of the pressing force increasing mechanism)
213 Arm body 314 Rotary encoder (a part of the pressing force increasing mechanism)
330 Support plate (part of the pressure increase mechanism)
340 Support plate lifting mechanism (part of pressing force increasing mechanism)
361 Memory unit (part of the pressure increase mechanism)
R Transport path R1 Curved path

Claims (9)

A storage section that can store and store a plurality of sheets;
It is rotatable about a rotation axis parallel to the sheet accommodated in the accommodating portion, and is rotated about the rotation axis while being pressed by the sheet accommodated in the accommodating portion and contacting the surface of the sheet. A roller for feeding the sheet;
An arm that rotatably supports the roller and swings about a first swing axis parallel to the rotation axis;
A separation wall for separating the sheet that contacts the roller from the other sheet by imparting a conveyance resistance to the sheet that is stacked and stored in the storage unit;
A conveyance path having a high resistance portion that is provided downstream of the separation wall and that imparts a conveyance resistance larger than the conveyance resistance imparted by the separation wall to the sheet;
For one sheet, after the leading edge of the sheet started to be fed by the roller reaches the separation wall and the sheet starts to separate from the other sheets, the sheet is fed by the rotation of the roller. And a pressing force increasing mechanism for increasing the pressing force of the roller against the sheet until the leading edge of the sheet passes through the high resistance portion. The arm is configured to be able to be bent about a second swing axis parallel to the first swing shaft located between the roller and the first swing shaft, and the first swing shaft A first arm extending from the second swinging shaft to the second swinging shaft, and extending from the second swinging shaft to the roller and swingable with respect to the first arm about the second swinging shaft A second arm,
The pressing force increasing mechanism is configured such that a contact angle of the roller that forms an acute angle between the second arm and the sheet that comes into contact with the roller when feeding by the roller is started. Increased until the leading edge of the sheet fed by the rotation of the roller passes through the high resistance portion after the leading edge reaches the separation wall and the sheet and other sheets start to separate. The sheet conveying apparatus according to claim 1, wherein the first arm is swung.   The sheet conveying apparatus according to claim 2, further comprising a sensor that detects that the contact angle has reached a predetermined angle when feeding of one sheet is started by the roller. . The pressing force increasing mechanism is
A drive mechanism for swinging the first arm;
Angle detection means for detecting the rotation angle of the first arm,
4. The sheet conveying apparatus according to claim 2, wherein the driving mechanism swings the first arm based on the rotation angle detected by the angle detection unit. 5. The arm has an arm body extending from the roller to the first swing shaft;
The pressing force increasing mechanism is fed by rotation of the roller after a leading edge of the sheet reaches the separation wall and separation of the sheet and other sheets starts. 2. The force for swinging the arm in a direction in which the pressing force applied to the sheet by the roller increases until the leading edge of the sheet passes through the high resistance portion is increased. The sheet conveying apparatus according to 1. The pressing force increasing mechanism is
A support plate for supporting the sheet accommodated in the accommodating portion;
A supporting plate lifting mechanism capable of moving at least a facing region facing the roller of the supporting plate in a direction facing the roller;
The support plate elevating mechanism is configured such that when a sheet is fed by the roller, the contact angle of the roller that forms an acute angle between the sheet that contacts the roller and the arm when the sheet starts feeding is determined by the leading edge of the sheet. The leading edge of the sheet fed by the rotation of the roller passes through the high resistance portion after reaching the separation wall and starting to separate the sheet from other sheets. The sheet conveying apparatus according to claim 1, wherein the facing region is moved in a direction away from the roller.   The sheet conveying apparatus according to claim 1, wherein the conveying path includes a curved path as the high-resistance portion.   The pressing force increasing mechanism includes a storage unit that stores data relating to a change in conveyance resistance with respect to a change in the position of the sheet in the conveyance path, and a conveyance amount detection unit that detects a conveyance amount of the sheet conveyed by the roller, The sheet conveying apparatus according to claim 1, wherein a pressing force of the roller against the sheet is increased based on the data and the conveyance amount by the conveyance amount detection unit. The transport path is provided with a sensor that detects the leading edge of the sheet at a position upstream from the high resistance portion and downstream from the separation wall.
8. The sheet conveyance according to claim 1, wherein the pressing force increasing mechanism increases a pressing force of the roller against the sheet when a leading edge of the sheet is detected by the sensor. 9. apparatus.

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