The present invention relates to a medium feeding apparatus for transporting a medium and an image reading apparatus having the medium feeding apparatus.
Scanners, which are example image reading apparatuses, and printers, which are example recording apparatuses, are provided with a feeding apparatus for feeding a medium. Some feeding apparatuses employ a system for separating a medium, for example, a system for separating a medium by nipping the medium with a separation roller and a feeding roller. To the separation roller, rotation resistance or reverse rotation torque is applied. Such a feeding apparatus is described, for example, in JP-A-2016-72833.
The inventors have found that the contact between the separation roller and the medium can cause a decrease in the separation performance and provide a method for solving the problem.
An advantage of some aspects of the invention is that there is provided a medium feeding apparatus capable of reducing the decrease in the separation performance and an image reading apparatus having the medium feeding apparatus.
A medium feeding apparatus according to an aspect of the invention includes a mounting section on which a medium to be fed is mounted, a feeding roller configured to feed the medium mounted on the mounting section, a separation roller configured to nip and separate the medium with the feeding roller therebetween, and a regulation section disposed downstream of the nipping position between the feeding roller and the separation roller, and the regulation section being configured to come into contact with the medium from the side of the separation roller so as to regulate the contact of the medium to be fed and the separation roller.
The inventors have found that the contact between the separation roller and the medium being fed downstream of the nipping position between the separation roller and the feeding roller can cause a decrease in the separation performance. Specifically, the inventors have found that when a medium is subjected to a feeding force from another feeding roller pair on the downstream side of the nipping position, the medium that has wound around the separation roller on the downstream side of the nipping position between the separation roller and the feeding roller can cause the separation roller to rotate in a forward direction. The rotation of the separation roller in the forward feeding direction can allow the medium not to be multi-fed to be fed downstream.
In this aspect, there is provided a regulation section disposed downstream of the nipping position between the feeding roller and the separation roller, the regulation section being disposed at a position different from the separation roller in an intersecting direction that intersects a medium feeding direction, and the regulation section being configured to regulate the contact of the medium to be fed and the separation roller. With this regulation section, on the downstream side of the nipping position between the separation roller and the feeding roller, the area in which a medium comes into contact with the separation roller can be reduced or the contact can be prevented. As a result, the rotation of the separation roller in the forward feeding direction due to the medium to be fed can be reduced, that is, the decrease in the separation performance can be reduced. The expression “regulate the contact” includes to completely prevent a medium from coming into contact with the separation roller and to reduce the contact of a medium being in contact with the separation roller.
In this medium feeding apparatus, a part of the regulation section may be within an area of the separation roller when viewed in the intersecting direction. In this structure, since at least a part of the regulation section is within an area of the separation roller when viewed in the medium width direction that intersects the medium feeding direction, at a position near the nipping position between the separation roller and the feeding roller, winding of a medium around the separation roller can be reduced. Accordingly, the winding of a medium around the separation roller can be more reliably reduced.
In the medium feeding apparatus, when the nipping position between the feeding roller and the separation roller is a first nipping position, the regulation section may be located above a tangent line at the first nipping position when viewed in the intersecting direction.
With this structure, when the nipping position between the feeding roller and the separation roller is a first nipping position, the regulation section does not protrude from a tangent line at the first nipping position toward the feeding roller side when viewed in the medium width direction that intersects the medium feeding direction. Accordingly, the occurrence of damage such as scratches due to the regulation section to a medium to be fed can be reduced.
The medium feeding apparatus may further include a feeding roller pair disposed downstream of the first nipping position, the feeding roller pair being configured to further feed the medium toward the downstream side, in which when the nipping position of the feeding roller pair between which the medium is to be nipped is a second nipping position, the regulation section may be located above a tangent line at the second nipping position when viewed in the intersecting direction.
With this structure, the medium feeding apparatus further includes a feeding roller pair disposed downstream of the first nipping position, the feeding roller pair being configured to further feed the medium toward the downstream side, in which when the nipping position of the feeding roller pair between which the medium is to be nipped is a second nipping position, the regulation section does not protrude from a tangent line at the second nipping position when viewed in the medium width direction that intersects the medium feeding direction. Accordingly, the occurrence of damage such as scratches due to the regulation section to a medium to be fed can be reduced.
In the medium feeding apparatus, the regulation section may protrude from a straight line connecting the first nipping position and the second nipping position toward the feeding roller side when viewed in the intersecting direction. With this structure, the regulation section protrudes from a straight line connecting the first nipping position and the second nipping position toward the feeding roller side when viewed in the medium width direction that intersects the medium feeding direction. Accordingly, the contact of a medium with the separation roller can be more reliably reduced.
In the medium feeding apparatus, at least two separation rollers may be disposed in the intersecting direction, and the regulation section may be disposed between the two separation rollers.
With this structure, since at least two separation rollers is disposed in the intersecting direction and the regulation section is disposed between the two separation rollers, at least two separation rollers can commonly use the regulation section, and the cost increase of the apparatus can be reduced.
In the medium feeding apparatus, at least two separation rollers may be disposed in the intersecting direction, and the regulation sections may be disposed on both sides of the two separation rollers.
With this structure, since at least two separation rollers are disposed in the intersecting direction and the regulation sections are disposed on both sides of the two separation rollers, the contact of a medium with the separation roller can be more reliably reduced.
In the medium feeding apparatus, the regulation section may comprise a fixed member that is not moved by the contact with a medium. With this structure, when the regulation section comprises a fixed member that is not moved by the contact with a medium, the above-described functional effects can be achieved.
In the medium feeding apparatus, a corner portion of the fixed member in the intersecting direction may be rounded or chamfered. With this structure, since a corner portion of the fixed member in the intersecting direction is rounded or chamfered, the occurrence of damage such as scratches due to a corner portion of the fixed member to a medium to be fed can be reduced.
The medium feeding apparatus may further include a supporting member that supports the separation roller and forms a medium feeding path, in which the fixed member may be provided in the supporting member.
With this structure, the medium feeding apparatus further includes a supporting member that supports the separation roller and forms a medium feeding path, and the fixed member is provided in the supporting member. Accordingly, it is not necessary to additionally provide a dedicated mechanism for installing the fixed member and additional cost can be prevented.
In the medium feeding apparatus, the fixed member may be integrally provided with the supporting member. With this structure, since the fixed member is integrally provided with the supporting member, the cost can be further reduced.
In the medium feeding apparatus, the regulation section may comprise a roller configured to come into contact with the medium and rotate. With this structure, since the regulation section comprises a roller configured to come into contact with the medium and rotate, damage to a medium due to the friction between the regulation section and the medium can be reduced.
In the medium feeding apparatus, a plurality of fixed members may be disposed in the intersecting direction. With this structure, since a plurality of fixed members are disposed in the medium width direction that intersects the medium feeding direction, the contact of a medium with the separation roller can be more reliably reduced.
In the medium feeding apparatus, the regulation section may be configured to be moved toward or away from the medium feeding path and moved toward or away from the medium feeding path depending on the medium type.
With this structure, the regulation section is configured to be moved toward or away from the medium feeding path and moved toward or away from the medium feeding path depending on the medium type. Accordingly, for example, when a medium that has high stiffness and is not easily bent is fed, the regulation section is moved away from the medium feeding path, and thereby the stiff and less flexible medium can be appropriately fed.
According to another aspect of the invention, an image reading apparatus includes a reading section configured to read a medium and any one of the above-described medium feeding apparatuses configured to transport the medium to the reading section. According to this aspect, in the image reading apparatus, some of the above-described functional effects can be achieved.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
Hereinafter, a medium feeding apparatus and an image reading apparatus according to an embodiment of the invention will be described with reference to the drawings. In this embodiment, as an example image reading apparatus, a document scanner (hereinafter, simply referred to as a scanner 1) that can read an image on at least one of the front surface and the back surface of a document (hereinafter, referred to as a document P), which is an example medium, will be described.
In an X-Y-Z coordinate system in the drawings, an X direction denotes an apparatus width direction and a document width direction that intersects a document feeding direction (transport direction). A Y direction denotes the document feeding direction (transport direction). A Z direction intersects the Y direction and is approximately orthogonal to a surface of a document to be transported. A +Y direction side denotes an apparatus front side, and a −Y direction side denotes an apparatus back side. A left side viewed from the apparatus front side denotes a +X direction and a right side denotes a −X direction. A +Z direction side denotes an apparatus upper side (including upper sections, upper surfaces, and the like), and a −Z direction side denotes an apparatus lower side (including lower sections, lower surfaces, and the like). It should be noted that as is clear from
Hereinafter, the scanner 1, which is an example image reading apparatus according to the embodiment of the invention, will be described mainly with reference to
A document mounting section 11 on which a document P to be fed can be mounted is provided on the apparatus back side of the apparatus body 2. The document mounting section 11 can be detachably attached to the apparatus body 2. The document mounting section 11 is provided with a pair of edge guides (a first edge guide 12A and a second edge guide 12B) for guiding side edges of a document P in the width direction (X-axis direction) that intersects the feeding direction (Y-axis direction) of the document P.
The document mounting section 11 is provided with a first paper support 8 and a second paper support 9. The first paper support 8 and the second paper support 9 can be stored inside the document mounting section 11 and can be pulled out from the document mounting section 11 as illustrated in
The apparatus body 2 has an operation panel 7 on the apparatus front side of the upper unit 4. On the operation panel 7, a user interface (UI) for setting various settings for reading, for executing a reading operation, for displaying reading setting contents, or the like is implemented. The operation panel 7 is a touch panel through which both of a displaying operation and an inputting operation can be performed. The operation panel 7 serves as an operation section for various operations and a display section for displaying of various information. A feed port 6 that is connected to the inside of the apparatus body 2 is provided in an upper portion of the upper unit 4. A document P mounted on the document mounting section 11 is fed from the feed port 6 toward a reading section 20 provided in the apparatus body 2. A discharge tray 5 for receiving a discharged document P is provided on the apparatus front side of the lower unit 3.
A document feeding apparatus 50 according to the embodiment of the invention, that is, a document feeding path in the scanner 1 will be described mainly with reference to
In
The document mounting section 11 is disposed on the most upstream side of the document feeding path T. On the downstream side of the document mounting section 11, the feeding roller 14, which feeds a document P mounted on the document mounting section 11 toward the reading section 20, and the separation roller 15, which nips the document P with the feeding roller 14 and separates the document P, are disposed.
The feeding roller 14 comes into contact with a lowermost document P of documents P mounted on the document mounting section 11. Accordingly, when a plurality of documents P are set on the document mounting section 11 in the scanner 1, the documents P are fed sequentially from the document P on the side of the document mounting section 11 toward the downstream side. To the document mounting section 11, a mount detection section 35, which serves as a mount detection unit, for detecting whether a document P is mounted on the document mounting section 11 is provided.
Until the start of feeding, a document P that is being mounted on the document mounting section 11 is regulated by a flap 24 such that a leading edge of the document P does not enter a feeding standby position, that is, between the feeding roller 14 and the separation roller 15. The flap 24 is provided to a pressing unit 23 (
The contact regulating section 21 is disposed on a side of the feeding roller 14 in the sheet width direction. The contact regulating section 21 can be switched by a motor (not illustrated) between a regulation state for regulating the forward movement of the pressing unit 23 toward the feeding roller 14 and a release state for allowing the forward movement of the pressing unit 23 toward the feeding roller 14. Until feeding is started, a stack of documents mounted on the document mounting section 11 is supported from below by the contact regulating section 21 that is in the regulation state such that the documents are separated from the feeding roller 14 so as not to come into contact with the feeding roller 14. After the start of feeding, the contact regulating section 21 moves downward such that the lowermost document P of the stack of documents comes into contact with the feeding roller 14 and the flap 24 becomes to be able to swing (the orientation can be switched). By the rotation of the feeding roller 14, the lowermost document P is fed downstream and the document P being fed downstream causes the flap 24 to swing to the downstream side to open the document feeding path.
Two separation rollers 15 are disposed to be symmetric with respect to a central position in the document width direction. The separation rollers 15 are illustrated in
With the rotation torque from a motor for feeding (not illustrated), the feeding roller 14 rotates in the counterclockwise direction in
When no document P is provided or only one sheet of document P is provided between the feeding roller 14 and the separation roller 15, the separation roller 15 is rotated (in the clockwise direction in
A transport roller pair 16, the reading section 20 for reading images, and a discharging roller pair 17 are disposed downstream of the feeding roller 14. The transport roller pair 16 includes a transport driving roller 16a that is driven to rotate by a motor for transport (not illustrated) and a transport driven roller 16b that follows the transport driving roller 16a to rotate. In this embodiment, two separation rollers 16b are disposed to be symmetric with respect to the central position in the document width direction as illustrated in
As illustrated in
On the downstream side of the sound detector 33, a first document detector 31 is disposed. The first document detector 31 is, for example, an optical sensor that includes a light emitting unit 31a and a light receiving unit 31b that face each other across the document feeding path T. The light receiving unit 31b sends an electrical signal that indicates the intensity of a detection light to the controller 40. A document P being transported interrupts the detection light emitted from the light emitting unit 31a and the electrical signal indicating the intensity of the detection light changes. By the signal change, the controller 40 can detect the passage of a leading edge or a trailing edge of the document P.
On the downstream side of the first document detector 31, a multi-sheet feed detector 30 that detects multi-sheet feeding of documents P is disposed. The multi-sheet feed detector 30 includes an ultrasonic transmitter 30a and an ultrasonic receiver 30b for receiving ultrasonic waves that face each other across the document feeding path T. The ultrasonic receiver 30b sends an electrical signal that indicates the intensity of the detected ultrasonic waves to the controller 40. When multi-sheet feeding of documents P occurs, the electrical signal indicating the intensity of the ultrasonic waves changes and the electric signal change enables the controller 40 to detect the multi-sheet feeding of the documents P.
On the downstream side of the multi-sheet feed detector 30, a second document detector 32 is disposed. The second document detector 32 is a contact sensor that has a lever. In response to passage of a leading edge or a trailing edge of a document P, the lever rotates and the electrical signal sent from the second document detector 32 to the control section 40 changes. By the signal change, the controller 40 can detect the passage of the leading edge or the trailing edge of the document P. The controller 40 can determine the location of the document P in the document feeding path T with the above-described first document detector 31 and the second document detector 32.
The reading section 20, which is disposed on the downstream side of the second document detector 32, includes an upper read sensor 20a that is provided on the side of the upper unit 4 and a lower read sensor 20b that is provided on the side of the lower unit 3. In this embodiment, as an example, the upper read sensor 20a and the lower read sensor 20b are configured as a contact image sensor (CIS) module.
After an image on at least one of the front side and the back side of a document P has been read in the reading section 20, the document P is nipped by the discharging roller pair 17 that is disposed downstream of the reading section 20 and discharged from a discharge port 18 that is provided on the apparatus front side of the lower unit 3. The discharging roller pair 17 includes a discharge driving roller 17a that is driven to rotate by a motor for transport (not illustrated) and a discharge driven roller 17b that follows the discharge driving roller 17a to rotate. Two discharge driven rollers 17b are disposed to be symmetric with respect to the central position in the document width direction as illustrated in
With reference to
In the state in
In the state in
However, as described above, when the lowermost document P1 to be fed winds around the separation roller 15 to some extent on the downstream side of the nipping position between the separation roller 15 and the feeding roller 14, the separation roller 15 that will be rotated in the document returning direction b is continuously rotated in the forward feeding direction a. As a result, the document P2 about to be fed is further fed to the downstream side than expected and can cause separation failure. In other words, the rotation of the separation roller 15 in the document returning direction b delays. Furthermore, the document P1 holds the separation roller 15 upward against an urging member (not illustrated) that urges the separation roller 15 toward the feeding roller 14, and an appropriate nipping force may not be provided, resulting in separation failure.
The state in
To solve the problems, the document feeding apparatus 50 according to the embodiment is provided with a regulation section 42 on the downstream side of the nipping position between the feeding roller 14 and the separation roller 15. The regulation section 42 is configured to come into contact with a document P1 from the side of the separation roller 15 to regulate the contact between the document P1 to be fed and the separation roller 15 as illustrated in
Hereinafter, the regulation section 42 will be further described.
In this embodiment, the regulation section 42 and the path forming member 22 are separated parts; however, the regulation section 42 may be integrally provided with the path forming member 22. With this structure, the cost can be further reduced.
The regulation section 42 according to the embodiment is a fixed member that is not moved by the contact with a document. As illustrated in
The regulation section 42 according to the embodiment is disposed between the two separation rollers 15 as illustrated in
Hereinafter, the regulation section 42 will be described further in detail with reference to
A reference numeral L1 denotes a straight line that connects the rotation central position C1 and the rotation central position C2. A reference numeral L2 denotes a straight line that connects the rotation central position C3 and the rotation central position C4. A reference numeral L3 denotes a tangent line at the nipping position N1. A reference numeral L4 denotes a tangent line at the nipping position N2. A reference numeral L5 denotes a straight line that connects the nipping position N1 and the nipping position N2.
A reference numeral 25a denotes a surface of a path that is formed by a path forming member 25 (
It is apparent from
The regulation section 42 does not protrude from the tangent line L3 at the nipping position N1, which is a first nipping position, toward the feeding roller 14 side. With this structure, the occurrence of damage such as scratches due to the regulation section 42 to a document P to be fed can be reduced.
Furthermore, the regulation section 42 does not protrude from the tangent line L4 at the nipping position N2, which is a second nipping position, toward the feeding roller 14 side. With this structure, the occurrence of damage such as scratches due to the regulation section 42 to a document P to be fed can be reduced.
The regulation section 42 protrudes from the straight line L5, which connects the nipping position N1 and the nipping position N2, toward the feeding roller 14 side. Accordingly, the winding of a document P around the separation roller 15 can be more reliably regulated.
The above-described embodiment is a mere example, and for example, the regulation section may be modified in various ways as described below. A regulation section 43 illustrated in
Regulation sections 44 illustrated in
In the structure in
The regulation sections 42, 43, and 44 in the above-described embodiments may be moved toward or away from the document feeding path. For example, in the case of the regulation section 42, a position indicated by a line (chain double-dashed line) 42-1 in
For example, when a document P that has high stiffness and is not easily bent is fed, the regulation section 42 is moved away from the document feeding path, and thereby the stiff and less flexible document P can be appropriately fed. Examples of the stiff and less flexible document include a document (for example, a plastic card) of a card size defined by ISO/IEC 7810 ID-1.
In this step, the controller 40 can acquire the document type, for example, based on the document type that has been set via the operation panel 7. Alternatively, when a detecting unit for detecting positions of the pair of the edge guides 12A and 12B (
When the controller 40 determines that the document is a high-stiffness document (Y in step S103), the regulation section 42 is switched to the reverse position (step S105). When the controller 40 determines that the document is not a high-stiffness document (N in step S103), the regulation section 42 is switched to the forward position (step S104). Then, the document is fed and read (step S106). When the forward position of the regulation section 42 is a default position, no control is performed in step S104.
In the above description, the scanner, which is an example image reading apparatus, has been described as the embodiments of the medium feeding apparatus of the invention. Alternatively, embodiments of the invention may be applied to recording apparatuses that have a recording head for performing recording onto a medium, such as printers. In such a case, in the structure in
The entire disclosure of Japanese Patent Application No. 2018-058212, filed Mar. 26, 2018 is expressly incorporated by reference herein.
Number | Date | Country | Kind |
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JP2018-058212 | Mar 2018 | JP | national |
Number | Name | Date | Kind |
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4928951 | Fukui | May 1990 | A |
9340381 | Matsushita | May 2016 | B2 |
20100303529 | Shiba | Dec 2010 | A1 |
20180118486 | Lin | May 2018 | A1 |
Number | Date | Country |
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2016-072833 | May 2016 | JP |
Number | Date | Country | |
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20190291984 A1 | Sep 2019 | US |