JP2010120742A - Feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a feeder whose service life can be extended by designating, out of a plurality of transportation rollers, only specified transportation rollers as ones to be replaced. <P>SOLUTION: In the feeder 1, a first drive system 15, a control device 18, and a pressure application system 19 operate such that the transportation force of the specified transportation rollers 121 is greater than the transportation force of other transportation rollers 122, whereby, when transporting a medium P, a load applied on the specified transportation rollers 121 is increased and a load applied on the other transportation rollers 122 is reduced. Thus, when a plurality of media P are transported by transportation rollers 12, the wear of the specified transportation rollers 121 accelerated, thereby the specified transportation rollers 121 reach their wear limit early as they wear quickly, whereas wear in the other transportation rollers 122 is suppressed. Accordingly, duration in which the other transportation rollers 122 reach their wear limit can be extended. Therefore, the service life of the feeder 1 can be extended by replacing only the specified transportation rollers 121. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a feeding device that feeds a sheet-like medium in a conveyance direction.

  The feeding device includes a conveyance roller that conveys a sheet-like medium. In general, a plurality of conveying rollers are provided inside the feeding device. The plurality of transport rollers are continuously arranged on the downstream side in the transport direction with respect to the brake roller that prevents the double feeding of the medium. Each transport roller is worn by transporting the medium. Further, since each conveying roller conveys the medium in contact with the brake roller, the force caused by the frictional force applied to the medium by the brake roller via the medium conveyed by each conveying roller. That is, the tensile force acts in the direction opposite to the conveying direction. Accordingly, each transport roller is further worn out because the medium is transported in the transport direction against the tensile force. When the wear of each transport roller reaches the preset wear limit of the transport roller, the conventional feeding device cannot be used unless the transport roller that has reached the wear limit is replaced, and has a lifetime.

  Therefore, from the viewpoint of extending the life of the feeding device, it is conceivable to replace the conveying roller that has reached the wear limit. When exchanging a conveyance roller, the easiness of exchange is calculated | required. For example, as disclosed in Patent Documents 1 and 2 below, a mechanism of a transport roller that has been conventionally easily replaced has been proposed.

JP-A-11-227777 JP 2003-118875 A

  However, even if it is easy to replace the transport rollers, if the transport roller wears out and the wear of the transport rollers reaches the wear limit of the transport rollers, all the transport rollers of the feeding device must be replaced. The point is the same. In addition, because of the configuration of the apparatus, there are a place where the exchange of the conveyance roller is easy and a place where the exchange of the conveyance roller is complicated, so it is not preferable to exchange all the conveyance rollers of the feeding device. In other words, the operation of replacing all the transport rollers of the feeding device is not preferable because it involves a complicated and time-consuming operation. In addition, since all the transport rollers of the feeding device are replaced every time the transport rollers are replaced, the replacement cost of the transport rollers is high.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a feeding device capable of extending the service life by replacing only a specific transport roller among a plurality of transport rollers. And

  In order to solve the above-described problems and achieve the object, a feeding device according to the present invention is configured to contact and rotate a sheet-like medium so that the medium is conveyed with respect to the contacted medium. A separator roller that applies a conveying force, which is a force that is sent in a direction, and a friction that is arranged to be able to contact the separator roller and that is smaller than the conveying force and opposite to the conveying direction with respect to the contacting medium. A brake roller that applies force, and a plurality of brake rollers that are continuously arranged downstream of the brake roller in the transport direction, and that contact and rotate the medium, thereby causing the transport force to act on the contacted medium A plurality of transport rollers, and a plurality of driven rollers disposed so as to be in contact with each other and rotatably supported by the plurality of transport rollers. A transport force increasing means for increasing the transport force of a specific transport roller among the plurality of transport rollers with respect to the transport force of other transport rollers excluding the specific transport roller among the plurality of transport rollers; It is characterized by that.

  Further, in the feeding device, the transport force increasing means increases a pressure applied to the medium by the specific transport roller relative to a pressure applied to the medium by the other transport roller, or The amount of movement of the medium in the carrying direction by a specific carrying roller per unit time is increased relative to the amount of movement of the medium in the carrying direction by the other carrying roller per unit time. It is preferable to do either.

  Further, in the feeding device, the plurality of transport rollers are formed on an outer peripheral portion, have a medium contact portion that contacts the medium and allows wear, and at least the medium contact portion is formed in the transport direction. The specific conveyance roller is disposed so as to protrude from the guide member constituting the conveyance path toward the inside of the conveyance path, and the specific conveyance roller has a radius of a portion protruding from the guide member in the medium contact portion of the specific conveyance roller It is preferable that the thickness in the direction is arranged to be thicker than the thickness in the radial direction of the portion of the medium contact portion of the other transport roller that protrudes from the guide member.

  The feeding device includes a first drive system that drives the specific transport roller and a second drive system that drives the other transport roller, the first drive system and the second drive system. Are preferably independent of each other.

  In the feeding device, it is preferable that the specific transport roller is disposed between the brake roller and the other transport roller.

  In the present invention, by increasing the conveyance force of a specific conveyance roller with respect to the conveyance force of another conveyance roller by the conveyance force increasing means, the burden when conveying the medium on the specific conveyance roller is increased. It is possible to reduce the burden when the medium is transported by the transport rollers. For this reason, when a large number of media are transported by the transport roller, the wear of the specific transport roller proceeds, so that the specific transport roller reaches the wear limit early, but the wear of the other transport rollers is suppressed. Therefore, the period until the other transport rollers reach the wear limit can be lengthened, for example, the number of media that can be transported can be increased. Thus, even if a specific transport roller reaches the wear limit, the other transport rollers do not reach the wear limit. Therefore, the apparatus can be used by replacing only the specific transport roller. In other words, the period until the other transport rollers reach the wear limit is lengthened, and only the specific transport rollers are set as replacement targets, so that the life of the apparatus can be extended. In addition, since only a specific transport roller is to be replaced, only a specific transport roller can be used so that the device can be used even if the specific transport roller reaches the wear limit and the device cannot be used. Therefore, the replacement cost of the transport roller can be reduced.

  Hereinafter, an embodiment of a feeding device according to the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiments.

Embodiment
Hereinafter, the feeding device according to the embodiment will be described. FIG. 1 shows a schematic side view of a feeding device according to an embodiment.

  The feeding device 1 sends out a sheet-like medium P such as paper in the transport direction in which the medium P is transported. Hereinafter, the sheet-like medium P is simply referred to as a medium P. In the embodiment, the feeding device 1 is incorporated in an image reading device that captures an image of the medium P using two image sensors and generates a captured image corresponding to the medium P. The feeding device 1 conveys the medium P toward the imaging position where each imaging element images the medium P. That is, the transport destination of the medium P by the feeding device 1 is the imaging position. One image sensor is provided in each of the reading units 20 and 21. For example, the reading unit 20 is disposed above the conveyance path formed in the conveyance direction, and the reading unit 21 is disposed below the conveyance path, for example. The feeding device 1 includes a separator roller 10, a brake roller 11, a plurality of transport rollers 12, a plurality of driven rollers 13, a transport roller replacement unit 14, a first drive system 15, and a second drive system 16. The guide member 17, the control device 18, and the pressure applying device 19 are provided.

  Here, a pickup roller 22, a separator roller 10, a transport roller 12, and a discharge roller pair 23, which will be described later, are continuously arranged along the transport direction in this order. The arrangement interval between these rollers adjacent to each other in the transport direction is such that the front end in the transport direction of the medium P sent by the upstream roller in the transport direction is the downstream roller in the transport direction. The distance can be any distance as long as the medium P can be reliably transferred between the rollers adjacent to each other.

  As shown in FIG. 1, the separator roller 10 sends out the medium P sent from a paper feed tray (not shown) by the pickup roller 22 in the transport direction. The separator roller 10 is disposed downstream of the pickup roller 22 in the transport direction in the transport path where the medium P is transported. The separator roller 10 has a rotation shaft disposed, for example, above the conveyance path. The separator roller 10 is supported so as to be rotatable around its rotation axis. In the embodiment, the separator roller 10 is supported by a housing (not shown) of the feeding device 1.

  The separator roller 10 is connected to a drive motor 10a, and the separator roller 10 rotates in a direction in which the medium P is sent out in the transport direction when electric power is supplied from the control device 18 to the drive motor 10a (the same figure). Counterclockwise). Hereinafter, the rotation refers to rotation in a direction in which the medium P is sent out in the transport direction. The separator roller 10 contacts and rotates with the medium P sent out from the paper feed tray by the pickup roller 22, so that a transporting force that is a force sent in the transport direction is applied to the medium P in contact with the separator roller 10. Make it work. As a result, the separator roller 10 sends out the medium P in contact with the separator roller 10 in the transport direction.

  The pickup roller 22 is disposed to face the paper feed tray. The pickup roller 22 is supported so as to be rotatable around its rotation axis. In the embodiment, the pickup roller 22 is supported by a switching device (not shown). The pickup roller 22 is connected to a drive motor 22a, and the pickup roller 22 rotates when electric power is supplied from the control device 18 to the drive motor 22a (counterclockwise in the figure). The drive motor 22a may be omitted, the pickup roller 22 may be connected to the drive motor 10a of the separator roller 10, and the pickup roller 22 may be rotated by the drive motor 10a. Further, the pickup roller 22 is in a contact state in which the pickup device 22 can come into contact with the medium P placed on the paper feed tray by the switching device or a non-contact state in which the pickup roller 22 does not come into contact with the medium P placed on the paper feed tray. You can switch to either. When the medium P is being fed by the separator roller 10, the pickup roller 22 is brought into a non-contact state by the switching device. The pickup roller 22 is in contact with the medium P placed on the paper feed tray and rotates, thereby causing a conveying force to act on the medium P in contact with the pickup roller 22. As a result, the pickup roller 22 sends out the medium P in contact with the pickup roller 22 from the paper feed tray in the transport direction.

  The brake roller 11 prevents the separator roller 10 from feeding the medium P in a double manner. Specifically, the separation target medium that is the medium P that is sent in the transport direction together with the sending target medium by the pickup roller 22 is separated from the sending target medium that is the medium P that is in contact with the separator roller 10. The brake roller 11 faces the separator roller 10 and is disposed so as to be able to contact the separator roller 10. The brake roller 11 is disposed, for example, below the conveyance path. The brake roller 11 is supported so as to be rotatable around its rotation axis (clockwise in the figure). The brake roller 11 presses against the paper surface of the medium P that has entered between the separator roller 10 and the brake roller 11. Is supported to be. In the embodiment, the brake roller 11 is supported by a housing (not shown) of the feeding device 1. Further, the outer peripheral surface of the brake roller 11 is in contact with the outer peripheral surface of the separator roller 10 when the medium P does not enter between the separator roller 10 and the brake roller 11. The brake roller 11 has a torque limiter (not shown) attached to its rotating shaft. When the medium P enters between the separator roller 10 and the brake roller 11, the brake roller 11 receives the force for sending the medium P by the separator roller 10, that is, the conveying force of the separator roller 10 through the medium P. It will be. The brake roller 11 applies a force against the conveying force received via the medium P to the medium P that is in contact with the brake roller 11. That is, the brake roller 11 applies a frictional force that is smaller than the conveying force of the separator roller 10 and is in the direction opposite to the conveying direction to the medium P that is in contact by the torque limiter. Thereby, when a plurality of media P, for example, two media P, enter between the separator roller 10 and the brake roller 11, the brake roller 11 comes into contact with the separation target medium and applies the friction force to the separation target medium. The separation target medium is separated from the sending target medium on which the conveying force of the separator roller 10 acts. On the other hand, when one medium P enters between the separator roller 10 and the brake roller 11, the brake roller 11 comes into contact with the medium P, that is, the medium to be sent. When the conveying force of the separator roller 10 received exceeds the torque allowable upper limit of the torque limiter, the separator roller 10 rotates together with the separator roller 10.

  The transport roller 12 sends out the medium P sent by the separator roller 10 in the transport direction. The plurality of transport rollers 12 are continuously arranged downstream of the brake roller 11 in the transport direction. In the embodiment, seven transport rollers 12 are provided in the feeding device 1. Each of the transport rollers 12 has a rotation axis that is disposed below the transport path on the upstream side in the transport direction, for example, and is disposed above the transport path on the downstream side in the transport direction. Yes. That is, the plurality of transport rollers 12 are arranged so as to contact only one side of the medium P. Each transport roller 12 is supported so as to be rotatable around its rotation axis. Each conveyance roller 12 is supported by the housing of the feeding device 1 in the embodiment.

  Each transport roller 12 includes a core portion 12a and a medium contact portion 12b. Here, the core portion 12 a is an axial center portion of the transport roller 12. Moreover, the medium contact part 12b is formed in the outer peripheral part of the core part 12a. The medium contact portion 12b is made of, for example, a resin that can elastically contact the medium P, and can allow wear due to contact with the medium P. Each transport roller 12 is arranged such that at least the medium contact portion 12b protrudes from the guide member 17 constituting the transport path toward the inside of the transport path. Each transport roller 12 is in contact with the medium P and rotates to apply a transport force to the contacted medium. Thereby, each conveyance roller 12 sends out the contacted medium P in the conveyance direction.

  The driven roller 13 constitutes a roller pair together with the conveying roller 12. Each driven roller 13 is opposed to the conveying roller 12 that constitutes a pair of rollers, and the plurality of driven rollers 13 are arranged so as to be in contact with the plurality of conveying rollers 12, respectively. In the embodiment, seven driven rollers 13 are provided in the feeding device 1. Each driven roller 13 is supported so as to be rotatable around its rotation axis, and each driven roller 13 is supported so as to be pressed against the paper surface of the medium P that has entered between the opposite conveying rollers 12. Yes. In the embodiment, each driven roller 13 is supported by a housing (not shown) of the feeding device 1. Each driven roller 13 is in contact with the outer peripheral surface of the opposite transport roller 12 when the medium P does not enter between the opposite transport rollers 12. In addition, the specific driven roller 131 which is the driven roller 13 which comprises a roller pair with the specific conveyance roller 121 to be described later among the plurality of driven rollers 13 is arranged on the outer peripheral surface at a plurality of intervals in the circumferential direction. A reflector is provided. In the embodiment, the specific driven roller 131 is provided with, for example, four reflecting plates.

  Here, the conveyance roller 12 disposed on the most upstream side in the conveyance direction among the plurality of conveyance rollers 12 is a specific conveyance roller 121 in the embodiment. In other words, in the embodiment, the specific conveyance roller 121 is arranged on the upstream side in the conveyance direction with respect to the other conveyance rollers 122 excluding the specific conveyance roller 121 among the plurality of conveyance rollers 12. In other words, the specific transport roller 121 is disposed between the brake roller 11 and the other transport roller 122.

  The first drive system 15 constitutes a conveyance force increasing means together with the control device 18. The first drive system 15 drives a specific transport roller 121. The first drive system 15 includes, for example, a drive motor 15a and drive force transmission means (not shown). The drive motor 15a is, for example, a stepping motor. The drive motor 15a is connected to a specific transport roller 121 through a driving force transmission unit. The drive motor 15 a is driven by power supplied from the control device 18. In the embodiment, the drive motor 15a is driven by receiving a pulse signal from the control device 18. Thereby, the drive motor 15a can rotate the specific conveyance roller 121 via a drive force transmission means.

  The second drive system 16 drives the other transport rollers 122. The second drive system 16 is composed of, for example, a drive motor 16a and drive force transmission means 16b. The drive motor 16a is, for example, a stepping motor. The drive motor 16a is connected to each of the other transport rollers 122 via the driving force transmission means 16b. The drive motor 16 a is driven by power supplied from the control device 18. In the embodiment, the drive motor 16a is driven by receiving a pulse signal from the control device 18. The driving force transmitting means 16b transmits the driving force of the driving motor 16a to each of the other transport rollers 122. The driving force transmission means 16b is, for example, an endless belt that extends between the rotation shaft of the driving motor 16a and the plurality of other conveyance rollers 122 or between the plurality of other conveyance rollers 122. . That is, the second drive system 16 can rotate each of the other transport rollers 122 by supplying power from the control device 18. In the embodiment, the second drive system 16 can rotate each of the other transport rollers 122 by receiving a pulse signal from the control device 18.

  The control device 18 constitutes a conveyance force increasing means together with the first drive system 15. In the embodiment, the control device 18 is a power source for supplying power to the drive motor 22a, the drive motor 10a, the switching device, the drive motor 15a of the first drive system 15, and the drive motor 16a of the second drive system 16. It has a circuit inside. The control device 18 can drive the drive motor 22a and rotate the pickup roller 22 by supplying electric power from the power supply circuit to the drive motor 22a. Moreover, the control apparatus 18 can drive the drive motor 10a and can rotate the separator roller 10 by supplying electric power to the drive motor 10a from a power supply circuit. Further, the control device 18 is connected to the switching device and controls the switching device by supplying or stopping power supply from the power supply circuit to the switching device to bring the pickup roller 22 into a contact state. Or in a non-contact state. In addition, the control device 18 can drive the drive motor 15 a and rotate the specific transport roller 121 by supplying power from the power supply circuit to the drive motor 15 a of the first drive system 15. In addition, the control device 18 can drive the drive motor 16 a and rotate all the other transport rollers 122 by supplying power from the power supply circuit to the drive motor 16 a of the second drive system 16.

  Here, in the embodiment, the control device 18 independently supplies power supplied to the drive motor 15a of the first drive system 15 and power supplied to the drive motor 16a of the second drive system 16. That is, the control device 18 controls the first drive system 15 and the second drive system 16 separately. As a result, the first drive system 15 and the second drive system 16 are independent. That is, the control device 18 determines a specific movement amount that is a movement amount per unit time in the conveyance direction of the medium P by the specific conveyance roller 121 and a unit time in the conveyance direction of the medium P by the other conveyance rollers 122. The general movement amount that is the movement amount can be controlled separately. For this reason, the control device 18 can perform overfeed control of a specific transport roller 121 with respect to the other transport rollers 122. In the embodiment, the control device 18, for example, the radius of a specific transport roller 121 when it is in an unworn state, the radius of another transport roller 122 when it is in an unworn state, or a specific radius by the first drive system 15. The specific movement amount is set to be, for example, 1% larger than the general movement amount based on the rotation speed of the conveyance roller 121, the rotation speed of the other conveyance roller 122 by the second drive system 16, and the like. That is, in the embodiment, the control device 18 performs, for example, 1% overfeed control of the specific transport roller 121 with respect to the other transport rollers 122.

  The control device 18 is connected to the rotation sensor 18a. The rotation sensor 18a is, for example, a reflection type sensor disposed to face a specific driven roller 131. The control device 18 determines whether the specific driven roller 131 is based on a signal from the rotation sensor 18a that changes by detecting reflected light from a plurality of reflecting plates provided on the outer peripheral surface of the specific driven roller 131, for example. It is determined how many times the specific transport roller 121 has rotated during one rotation, and the rotational speed of the specific transport roller 121 is corrected. Specifically, while the specific driven roller 131 makes one rotation, for example, the control device 18 obtains a change in the number of pulse signals supplied to the drive motor 15a and determines how many times the specific conveyance roller 121 has rotated. To do. In other words, if the specific driven roller 131 that does not progress wear against the specific transport roller 121 is rotated by the specific transport roller 121, for example, once, the specific transport roller 121 increases with wear. Since the number of rotations of 121 increases, the number of pulse signals that must be supplied to the drive motor 15a by the control device 18 in order for the specific conveying roller 121 in an unworn state to make one rotation, for example, is used as a reference value. The control device 18 can determine how many times the specific transport roller 121 has rotated based on the amount of change from the reference value. More specifically, the total number of reference pulses, which is the number of pulse signals supplied to the drive motor 15a while the specific driven roller 131 is rotated by, for example, one specific transport roller 121 in an unweared state, It is stored in advance in a storage unit (not shown). The control device 18 obtains the total number of actual pulses that is the number of pulse signals supplied to the drive motor 15a while the specific driven roller 131 rotates, for example, and reads the total number of reference pulses from the storage unit. Then, the control device 18 obtains a value obtained by dividing the total number of actual pulses by the total number of reference pulses, and the divided value is obtained when the specific driven roller 131 is rotated by, for example, one rotation by the specific transport roller 121 in an unworn state. The rotational speed of one drive system 15 is multiplied. The control device 18 sets this value as the corrected rotation speed of the drive motor 15a.

  The control device 18 is connected to the medium detection sensors 18b and 18c, respectively. The medium detection sensor 18b is disposed between the reading unit 20 and the driven roller 13 that is disposed on the upstream side of the reading unit 20 in the transport direction and closest to the reading unit 20. It is an optical sensor. Further, the medium detection sensor 18 c is disposed between two driven rollers 13 that are downstream of the reading unit 21 in the transport direction and are continuously disposed closest to the reading unit 21. It is an optical sensor. Based on the signal from the medium detection sensor 18b and the signal from the medium detection sensor 18c, the control device 18 uses the other conveyance roller 122 to place one medium P between the medium detection sensor 18b and the medium detection sensor 18c. The conveyance speed of the medium P is kept constant. Specifically, the control device 18 supplies pulses supplied to the drive motor 16a of the second drive system 16 when the medium P is transported between the medium detection sensor 18b and the medium detection sensor 18c by the other transport rollers 122. The change in the number of signals is obtained, and the conveyance speed of the medium P by the other conveyance rollers 122 is corrected so that the amount of change in the conveyance speed of the medium P by the other conveyance rollers 122 is eliminated. Here, in order to keep the conveyance speed of the medium P by the other conveyance rollers 122 constant even if the wear of the other conveyance rollers 122 progresses, the other conveyance rollers 122 increase with the wear of the other conveyance rollers 122. It is necessary to increase the rotation speed. Therefore, the control device 18 determines the total number of pulses, which is the number of pulse signals supplied to the drive motor 16a while the medium P moves between the medium detection sensor 18b and the medium detection sensor 18c, and the medium P indicates the medium detection sensor 18b. And the actual medium movement time, which is the time required to move between the medium detection sensor 18c and the medium detection sensor 18c. The actual medium movement time is the total number of pulses. When the medium P is moved between the medium detection sensor 18b and the medium detection sensor 18c by another conveyance roller 122, the control device 18 applies the drive motor 16a of the second drive system 16. It is obtained by dividing by the number of supplied pulse signals per unit time, that is, the rotational speed of the drive motor 16a. Further, a reference medium time, which is a time required for the medium P to move between the medium detection sensor 18b and the medium detection sensor 18c by the other conveying roller 122 in an unworn state, is a storage unit (not shown) in the control device 18. Is stored in advance. The control device 18 reads the reference medium time from the storage unit, obtains a value obtained by dividing the actual medium moving time by the reference medium time, and further multiplies the obtained value by the total number of pulses to obtain a value obtained after correction. The rotational speed of the drive motor 16a is assumed. Since the actual medium time is longer than the reference medium time, the rotational speed of the drive motor 16a after correction is higher than the rotational speed of the drive motor 16a before correction. As described above, the control device 18 can increase the rotational speed of the drive motor 16a and keep the transport speed of the medium P by the other transport rollers 122 constant.

  That is, the control device 18 keeps the conveyance speed of the medium P by the specific conveyance roller 121 and the conveyance speed of the medium P by the other conveyance rollers 122 constant.

  The pressing device 19 is a conveying force increasing unit. The pressurizing device 19 makes the driven roller 13 come into contact with the transport roller 12 in a pressed state. The pressure device 19 is arranged corresponding to each driven roller 13. In the embodiment, the pressure applying device 19 is also arranged for the driven roller 232. That is, in the embodiment, eight pressure devices 19 are arranged. The pressing device 19 is disposed on the opposite side of the conveying roller 12 with respect to the driven roller 13 to be pressed. The pressure device 19 is composed of an urging member such as a spring, for example. In the feeding device 1, a specific pressure, which is a force with which a specific pressure device 191, which is a pressure device 19 corresponding to a specific driven roller 131, presses the specific driven roller 131 is a specific pressure among the driven rollers 13. The other pressurizing device 192 which is the pressurizing device 19 corresponding to the other driven roller 132 excluding the driven roller 131 is set to be larger than the general applied pressure which is the force for pressing the other driven roller 132. More specifically, for example, when each pressurizing device 19 is composed of a spring, the spring constant of a specific pressurizing device 191 is made larger than the spring constant of the other pressurizing device 192. The specific pressure can be made larger than the general pressure. Thereby, when the medium P enters between the transport roller 12 and the driven roller 13, the pressure applied to the medium P by the specific transport roller 121 is set to be higher than the pressure applied to the medium P by the other transport rollers 122. Can be bigger.

  The transport roller replacement unit 14 is configured to allow a specific transport roller 121 to be attached to and detached from the base 1 a of the feeding device 1. The transport roller replacement unit 14 includes a pair of holding members 141 and a pair of fixing members 142.

  2 to 4 are perspective views showing an outline of the specific transport roller 121 and the transport roller replacement unit 14. As shown in FIGS. 2 to 4, the holding member 141 supports a specific transport roller 121 in a rotatable manner. In particular, as shown in FIGS. 3A and 3B, the holding member 141 is connected to both axial ends of the specific transport roller 121, and the core portion 121 a of the specific transport roller 121 can freely rotate. I support it. Each holding member 141 has a protruding portion 141 b that protrudes radially outward of the specific conveying roller 121 from the main body portion 141 a that rotatably supports the core portion 121 a of the specific conveying roller 121. The holding member 141 can be engaged with the fixing member 142. In the embodiment, the holding member 141 can be prevented from being detached from the fixing member 142 when the main body portion 141 a is inserted into the insertion groove of the fixing member 142 and is engaged with the fixing member 142. In a state where the holding member 141 is inserted into the insertion groove of the fixing member 142 and is prevented from coming off, the holding member 141 is rotated around the axis of the specific conveyance roller 121 so that the protruding portion 141b enters the storage groove of the fixing member 142. Furthermore, when the guide member 171 corresponding to the specific transport roller 121 among the guide members 17 is placed above the specific transport roller 121, the holding member 141 is more reliably prevented from being detached from the fixed member 142. In this manner, the specific transport roller 121 can be attached to the feeding device 1. On the other hand, the opening / closing part 1b is erected with respect to the base 1a of the feeding device 1, the base 1a of the feeding device 1 is exposed to the outside, the guide member 171 is removed from above the specific conveying roller 121, and the holding member 141 is removed. Is rotated around the axis of the specific conveying roller 121 so that the projecting portion 141b rises from the housing groove of the fixing member 142 and then is pulled out, and when the holding member 141 is pulled out of the insertion groove of the fixing member 142, the specific conveying roller The roller 121 can be removed from the feeding device 1. In the embodiment, the rotation shaft portion of the drive motor 15 a can be inserted into one end portion of the specific transport roller 121. Furthermore, a biasing member (not shown) is provided at a portion where the core portion 121a of the specific transport roller 121 is connected to the drive motor 15a. This urging member urges the drive motor 15a inserted in the core portion 121a to the side opposite to the insertion direction. For this reason, when the holding member 141 is inserted into or pulled out from the fixing member 142, the specific conveying roller 121 is pressed against the driving motor 15 a along the axial direction of the holding member 141 and the fixing member 142 of the holding member 141. Perform the attachment and detachment work.

  As described above, when the opening / closing part 1b is raised with respect to the base 1a of the feeding device 1, the periphery of the specific transport roller 121 immediately after the separator roller 10 in the transport direction in the base 1a is exposed to the outside. The user can easily reach the specific transport roller 121. That is, the specific transport roller 121 can be easily replaced. Further, when the opening / closing part 1b is erected with respect to the base 1a of the feeding device 1 and the periphery of the specific transport roller 121 is exposed to the outside, the specific transport roller 121 is exposed to the outside only by removing the guide member 171. . For this reason, the user can exchange the specific conveyance roller 121 manually. That is, also in this respect, the specific transport roller 121 can be easily replaced. As described above, the feeding device 1 has the ease of replacement of the specific transport roller 121.

  The fixing member 142 is for fixing the arrangement position of the core portion 121 a of the specific transport roller 121 inside the feeding device 1 by inserting the holding member 141. The fixing member 142 is fixed at a position corresponding to the holding member 141 connected to both ends of the specific transport roller 121 in the base 1 a of the feeding device 1. The fixing member 142 has an insertion groove which is a recess into which the main body 141a of the holding member 141 can be inserted. For this reason, it is possible to insert the main-body part 141a of the holding member 141 in the insertion groove of the fixing member 142, or to pull out from this insertion groove. Still further, the fixing member 142 has a storage groove that is a recess extending in the transport direction, for example, from a position where the main body 141a of the holding member 141 is engaged. For example, the storage groove of the fixing member 142 is formed by rotating the protruding portion 141b around the rotation axis of the specific conveying roller 121 so that the protruding direction of the protruding portion 141b of the holding member 141 is along the conveying direction. 141b can be stored.

  In FIG. 1, a member indicated by reference numeral “23” is a discharge roller pair that discharges the medium P toward a discharge tray (not shown) of the feeding device 1. The discharge roller pair 23 includes a discharge roller 231 and a driven roller 232. The discharge roller 231 is the same roller as the transport roller 12, and the driven roller 232 is the same roller as the driven roller 13. The discharge roller 231 is disposed on the downstream side in the transport direction with respect to the transport roller 12, and is disposed below the transport path in the embodiment. The discharge roller 231 is supported so as to be rotatable around its rotation axis. The driven roller 232 faces the discharge roller 231 and is disposed in contact with the discharge roller 231. In the embodiment, the driven roller 232 is disposed above the conveyance path. In addition, the relationship between the driven roller 232 and the discharge roller 231 is the same as the relationship between the other driven rollers 132 and the other transport rollers 122.

  The discharge roller 231 rotates when the drive motor 23a is driven (counterclockwise in the figure). The drive motor 23a is, for example, a stepping motor. The drive motor 23a is driven by being supplied with power from the power supply circuit of the control device 18, in the embodiment, a pulse signal. That is, the discharge roller 231 rotates when electric power is supplied from the power supply circuit of the control device 18 to the drive motor 23a. Note that the drive motor 23a may be omitted, the discharge roller 231 may be connected to the drive motor 16a of the other transport roller 122, and the discharge roller 231 may be rotated by the drive motor 16a.

  Next, the operation of the feeding device 1 according to the embodiment will be described.

  FIG. 5 is a flowchart of the operation of the feeding device 1. First, in the feeding device 1, when a user pushes a delivery button (not shown) provided in the feeding device 1 in a state where the medium P is stacked on the paper feed tray of the feeding device 1, the control device 18. An instruction to start feeding the medium P is input to the controller P, and the control device 18 performs overfeed control on the specific transport roller 121 with respect to the other transport rollers 122 (step S100). The control device 18 supplies electric power to the drive motor 22a, the drive motor 10a, the drive motor 15a, the drive motor 16a, and the drive motor 23a to drive these motors, and the pickup roller 22, the separator roller 10, and the specific The transport roller 121, the other transport roller 122, and the discharge roller 231 are rotated. As a result, the medium P placed on the paper feed tray is transported along the transport direction. At this time, the control device 18 separately controls the drive motor 15a and the drive motor 16a, and the specific transport roller 121 and the other transport rollers 122 so that the specific movement amount is, for example, 1% larger than the general movement amount. To control. Here, in the feeding device 1, the first driving system 15, the control device 18, and the pressure device 19 increase the conveying force of the specific conveying roller 121 relative to the conveying force of the other conveying rollers 122. Thus, it is possible to increase the burden when the medium P is transported by the specific transport roller 121 and reduce the burden when the medium P is transported by the other transport rollers 122.

  Next, the control device 18 determines whether or not to correct the rotation speed (step S101). More specifically, since the signal from the medium detection sensor 18c changes when the rear end of the conveyance direction of the medium P conveyed by another conveyance roller 122 is detected by the medium detection sensor 18c, the control device 18 Based on the number of changes in the signal, the number of media P conveyed by the feeding device 1 can be determined. At this time, the control device 18 has a predetermined condition for correcting the rotation speeds of the specific transport roller 121 and the other transport rollers 122. In the embodiment, the medium P transported by the feeding device 1 is 10,000 sheets. Determine whether it has been reached. When the control device 18 determines that the medium P conveyed by the feeding device 1 has reached 10,000 sheets, the control device 18 determines to correct the rotation speeds of the specific conveyance roller 121 and the other conveyance rollers 122. The number of the media P transported by the feeding device 1 is stored in the storage unit in the control device 18 by the control device 18 every time the media detection sensor 18c detects the rear end of the transport direction of the media P. That is, it is updated.

  Next, when determining that the rotation speed is not corrected (No at Step S101), the control device 18 sets the value of the flag to “0” (Step S103). More specifically, the value of this flag is, for example, readable and writable with respect to the storage unit in the control device 18, and is controlled whenever the rear end in the transport direction of the medium P is detected by the medium detection sensor 18c. The device 18 sequentially writes and stores it in the storage unit in the control device 18, that is, it is updated. Here, the control device 18 updates the value of the flag stored in the storage unit to “0”.

  Next, when the value of the flag is set to “0”, the control device 18 determines whether or not the conveyance is finished (step S104). More specifically, the control device 18 determines whether or not the medium detection sensor 18b has not detected the medium P for a predetermined time after the medium detection sensor 18c detects the medium P. When the control device 18 determines that the medium detection sensor 18b has detected the medium P during this predetermined period, the control device 18 determines that the conveyance of the medium P is not completed, while, during this predetermined period, If it is determined that the medium detection sensor 18b has not detected the medium P, it is determined that the conveyance of the medium P has been completed.

  Next, when the control device 18 determines that the conveyance is not finished (No at Step S104), the control device 18 returns to Step S101 and performs the process of Step S102 or Step S103.

  Further, when the control device 18 determines that the conveyance is finished (Yes at Step S104), it determines whether or not the value of the flag is “1” (Step S105). Here, if it is determined not to correct the rotation speed, the value of the flag stored in the storage unit is “0”, and therefore the control device 18 denies the determination in this step.

  Next, when the control device 18 determines that the value of the flag is not “1”, that is, the value of the flag is “0” (No at Step S105), the control device 18 ends the feeding process of the feeding device 1. Here, since the control device 18 determines that the medium detection sensor 18b has not detected the medium P for a predetermined time after the medium detection sensor 18c detects the medium P, the control device 18 is driven. The supply of power to the motor 22a, the drive motor 10a, the drive motor 15a, the drive motor 16a, and the drive motor 23a is stopped, and the feeding process of the feeding device 1 is terminated.

  Further, when the control device 18 repeats the above processing and determines that the rotational speed is to be corrected (Yes at Step S101), the control device 18 sets the value of the flag to “1” (Step S102). Here, the control device 18 updates the value of the flag stored in the storage unit to “1”.

  Next, when the flag value is set to “1”, the control device 18 determines whether or not the conveyance is finished (step S104).

  Next, when the control device 18 determines that the conveyance has not ended (No at Step S104), the control device 18 returns to Step S101, determines that the rotation speed is to be corrected (Yes at Step S101), and sets the flag value to “1”. As it is (step S102), it is determined whether or not the conveyance is finished (step S104). That is, if the control device 18 determines that the conveyance has not been completed, it repeats the processes of steps S101, S102, and S104 until it determines that the conveyance has been completed.

  Next, when the control device 18 determines that the conveyance is finished (Yes at Step S104), it determines whether or not the value of the flag is “1” (Step S105). Here, since the value of the flag stored in the storage unit is “1”, the control device 18 affirms the determination in this step.

  Next, when determining that the value of the flag is “1” (Yes at Step S105), the control device 18 corrects the rotation speed of the specific transport roller 121 (Step S106). Specifically, first, the control device 18 obtains the total number of actual pulses during a specific rotation of the specific driven roller 131, for example. Next, the control device 18 reads the total number of reference pulses from the storage unit in the control device 18 while the specific driven roller 131 is rotated, for example, by the specific transport roller 121 in an unweared state. Next, the control device 18 obtains a value obtained by dividing the total number of actual pulses by the total number of reference pulses. Next, the control device 18 obtains a value obtained by multiplying the divided value by the rotation speed of the drive motor 15a when the specific driven roller 131 is rotated once, for example, by the specific conveying roller 121 in an unworn state. And the control apparatus 18 makes this value the rotational speed of the drive motor 15a after correction | amendment. The corrected value of the rotational speed of the drive motor 15a may be stored in the storage unit in the control device 18 by the control device 18, for example. In the case of such a configuration, the corrected rotational speed of the drive motor 15a is set by storing the corrected rotational speed value of the drive motor 15a in the storage unit in the control apparatus 18. That's right.

  Next, when the rotational speed of the specific transport roller 121 is corrected, the control device 18 corrects the rotational speed of the other transport rollers 122 (step S107). Specifically, first, the control device 18 obtains the total number of pulses and the actual medium moving time. Next, the control device 18 reads the reference medium time from the storage unit in the control device 18. Next, the control device 18 obtains a value obtained by dividing the actual medium moving time by the reference medium time. Next, the control device 18 obtains a value obtained by multiplying the obtained value by the total number of pulses. And the control apparatus 18 makes this value the rotational speed of the drive motor 16a after correction | amendment. The corrected value of the rotational speed of the drive motor 16a may be stored in the storage unit in the control device 18 by the control device 18, for example. In the case of such a configuration, the corrected rotational speed of the drive motor 16a is set by storing the corrected rotational speed value of the drive motor 16a in the storage unit in the control apparatus 18. That's right. Then, the control device 18 ends the feeding process of the feeding device 1.

  As described above, when a large number of media P are transported by the transport roller 12, the wear of the specific transport roller 121 proceeds, so that the specific transport roller 121 reaches the wear limit early, but the wear of the other transport rollers 122. Is suppressed. Therefore, the period until the other transport roller 122 reaches the wear limit can be lengthened, and for example, the number of media P that can be transported can be increased. As a result, even if a specific transport roller 121 reaches the wear limit, the other transport rollers 122 do not reach the wear limit. Therefore, the opening / closing portion 1b of the feeding device 1 is raised with respect to the base portion 1a to expose the base portion 1a to the outside, and the guide member 171 is removed from the base portion 1a of the feeding device 1 to replace only a specific conveying roller 121. Thus, the feeding device 1 can be used. That is, the period until the other conveyance roller 122 reaches the wear limit is lengthened, and only the specific conveyance roller 121 is an object to be replaced, so that the life of the feeding device 1 can be extended.

  Further, in the feeding device 1, only a specific transport roller 121 is to be replaced, so that only the specific transport roller 121 reaches the wear limit and the device can be used even if it cannot be used. In this case, since only a specific transport roller 121 needs to be replaced, the replacement cost of the transport roller 12 can be reduced.

  Further, in the feeding device 1, only a specific conveyance roller 121 among the plurality of conveyance rollers 12 is to be replaced, so that it is not necessary to identify the conveyance roller 12 that has reached the wear limit from among the plurality of conveyance rollers 12. It becomes. For this reason, in order to extend the life of the feeding device 1, it is possible to reduce the burden on the user required for the operation of replacing the conveying roller 12 that has reached the wear limit.

  In the embodiment, the specific movement amount is increased with respect to the general movement amount by the first drive system 15 and the control device 18, and the pressure applied to the medium P by the specific conveying roller 121 is changed by the pressure applying device 19. However, the present invention is not limited to this. In the present invention, the specific movement amount is increased with respect to the general movement amount by the first drive system 15 and the control device 18, or the pressure applied to the medium P by the specific conveying roller 121 is changed by another pressure device 19. Only one of the pressure applied to the medium P by the transport roller 122 may be performed.

  Further, the feeding device 1 includes a specific protruding portion thickness d1 which is a thickness in a radial direction of a portion protruding from the guide member 171 in the medium contact portion 121b of the specific conveying roller 121, and the other conveying rollers 122. The general protruding portion thickness d2 which is the thickness in the radial direction of the portion protruding from the guide member 172 in the medium contact portion 122b may be made different. Note that the guide member 172 corresponds to the guide member corresponding to the other conveyance roller 122 in the guide member 17, and in the embodiment, corresponds to the other conveyance roller 122 arranged immediately after the specific conveyance roller 121 in the conveyance direction. It is a guide member to do. FIG. 6 is a side view showing a modification of the main part of the feeding device 1. For example, as illustrated in FIG. 6, the feeding device 1 uses the transport roller replacement unit 14 to dispose a specific transport roller 121 such that the specific protruding portion thickness d1 is larger than the general protruding portion thickness d2. May be. When the specific conveying roller 121 is arranged so that the specific protruding portion thickness d1 is thicker than the general protruding portion thickness d2, the period until the wear of the specific conveying roller 121 reaches the wear limit, For example, it can be made longer than when the specific conveying roller 121 is arranged so that the specific protruding portion thickness d1 is equal to the general protruding portion thickness d2. That is, the service life of the specific transport roller 121 can be extended. Thereby, the replacement frequency of the specific conveyance roller 121 can be suppressed. In FIG. 6, what is indicated by reference numeral “122 a” is a core portion of another transport roller 122.

  In the embodiment, the transport roller 12 includes the core portion 12a and the medium contact portion 12b. However, the present invention is not limited to this. The conveyance roller 12 of the present invention may be a roller composed only of the medium contact portion 12b.

  In the embodiment, the feeding apparatus 1 is applied to, for example, an image reading apparatus, but the present invention is not limited to this. For example, the feeding device 1 may be applied to an image forming apparatus.

  As described above, the feeding device according to the present invention is useful as a feeding device that feeds a large number of sheet-like media, and is particularly useful as a feeding device that requires a longer life.

It is a side view (partial sectional view) showing an outline of a feeding device according to an embodiment. It is a perspective view which shows the outline of a specific conveyance roller and a conveyance roller exchange unit. It is a perspective view which shows the outline of a specific conveyance roller and a conveyance roller exchange unit. It is a perspective view which shows the outline of a specific conveyance roller and a conveyance roller exchange unit. It is a figure which shows the flowchart of operation | movement of a feeding apparatus. It is a side view (partial sectional view) showing a modification of the main part of the feeding device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Feeding device 10 Separator roller 11 Brake roller 12 Conveyance roller 12b Medium contact part 121 Specific conveyance roller 121b Medium contact part 122 Other conveyance rollers 122b Medium contact part 13 Driven roller 14 Conveyance roller exchange unit 15 1st drive system (conveyance) Power increase means)
15a drive motor 16 second drive system 16a drive motor 16b drive force transmitting means 17 guide member 18 control device (conveying force increasing means)
19 Pressure device (conveying force increasing means)
P Medium

Claims (5)

A separator roller that contacts and rotates a sheet-like medium to apply a conveying force, which is a force sent in the conveying direction in which the medium is conveyed, to the contacted medium;
A brake roller that is arranged so as to be in contact with the separator roller, and that exerts a friction force that is smaller than the transport force and opposite to the transport direction on the contacting medium;
A plurality of transport rollers that are continuously arranged downstream of the brake roller in the transport direction and contact and rotate the medium so that the transport force acts on the contacted medium;
A plurality of driven rollers arranged so as to be in contact with each of the plurality of transport rollers and rotatably supported;
A feeding device comprising:
A conveyance force increasing means for increasing the conveyance force of a specific conveyance roller among the plurality of conveyance rollers with respect to the conveyance force of other conveyance rollers excluding the specific conveyance roller among the plurality of conveyance rollers. Comprising
A feeding device characterized by that. The conveying force increasing means is
The pressure applied to the medium by the specific transport roller is increased relative to the pressure applied to the medium by the other transport roller, or the unit time in the transport direction of the medium by the specific transport roller Increasing the amount of movement per unit time with respect to the amount of movement per unit time of the medium in the conveyance direction by the other conveyance rollers,
The feeding device according to claim 1. The plurality of transport rollers are:
A medium contact portion that is formed on the outer peripheral portion and contacts the medium to allow wear;
At least the medium contact portion is disposed so as to protrude toward the inside of the conveyance path from a guide member that constitutes a conveyance path formed in the conveyance direction;
The specific transport roller has a radial thickness of a portion of the medium contact portion of the specific transport roller that protrudes from the guide member and protrudes from the guide member of the medium contact portion of the other transport roller. It is arranged to be thicker than the thickness in the radial direction of the part,
The feeding device according to claim 1. A first drive system for driving the specific transport roller;
A second drive system for driving the other transport roller;
With
The first drive system and the second drive system are independent;
The feeding device according to any one of claims 1 to 3, wherein The specific transport roller is disposed between the brake roller and the other transport roller.
The feeding device according to any one of claims 1 to 4, wherein

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