Image reading apparatus

An image reading apparatus includes a housing, a first guide, a second guide, a first conveyor, and a reader. The first guide provides a first path between a first opening and a second opening. The second guide provides a second path between a third opening and a junction where the first path intersects the second path. The first conveyor includes first and second drive rollers, first and second driven rollers, first and second springs. The first drive roller is disposed inside a path, which includes at least the second path, between the third opening and the second opening, while the second drive roller is disposed outside the path. The first spring biases the first driven roller toward the first drive roller with a first biasing force (F1). The second spring biases the second driven roller toward the second drive roller with a second biasing force (F2), where F2>F1.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Japanese Patent Application No. 2013-178875 filed on Aug. 30, 2013, the content of which is incorporated herein by reference in its entirety.

FIELD

Aspects described herein relate to an image reading apparatus.

BACKGROUND

A known image reading apparatus includes a housing, a first guide portion, a second guide portion, a reader and a conveyer. The housing includes a first introduction opening, a second introduction opening, and a discharge opening. The second introduction opening is disposed in one end side of the first introduction opening in a width direction. A width of the second introduction opening is less than that of the first introduction opening in the width direction. The discharge opening communicates with the first introduction opening and the second introduction opening. The first guide portion connects the first introduction opening and the discharge opening. The first guide portion includes a bent portion therein. The second guide portion is disposed in the housing. The second guide portion connects straightway the second introduction opening and a junction between the first guide portion and the second guide portion. The junction is disposed close to the bent portion of the first guide portion. The reader is disposed in the housing. The conveyer is disposed in the housing.

The conveyer includes a first conveyor portion. The first conveyor portion is disposed between the junction and the discharge opening. The first conveyor portion includes a first drive roller, a second drive roller, a first driven roller, and a second driven roller. The first drive roller is disposed inside a path between the second introduction opening and the discharge opening and one end side in the width direction. The second drive roller is disposed in center side with respect to the first drive roller and outside the path in the width direction. The first drive roller and the second drive roller are rotated by a drive force from a drive source. The first driven roller is opposed to the first drive roller to pinch a medium guided by the first guide portion. The second driven roller is opposed to the second drive roller to pinch a medium guided by the second guide portion.

BRIEF SUMMARY

According to an aspect of the disclosure, an apparatus comprising a housing, a first guide, a second guide, a first conveyor, and a reader. The first guide is disposed in the housing and is configured to provide a first path between a first opening and a second opening. The first guide comprises an first portion and a second portion. The first opening extends in a first direction. The second opening extends in the first direction. The second opening is in communication with the first opening. The first portion is inclined and where the first portion of the first guide extends from the first opening to a first position and the second portion of the first guide extends from the first position to the second opening. The second guide is disposed in the housing and is configured to provide a second path between a third opening and a junction. The junction is located where the first path intersects the second path. The third opening is in communication with the second opening and is offset from the first opening in a second direction. The third opening is formed in a position located at one side of the first opening in the first direction. The first conveyor comprises a first drive roller, a second drive, a first driven roller, a second driven roller, a first spring, and a second spring. The first conveyor is in the second portion of the first guide. The first drive roller is disposed inside a path between the third opening and the second opening. The path comprises at least the second path. The first drive roller is offset of a center of the first guide in the first direction. The second drive roller is disposed outside the path between the third opening and the second opening. A distance between the center of the first guide and the second drive roller is less than a distance between the center of the first guide and the first drive roller in first direction. The first driven roller opposes the first drive roller. The second driven roller opposes the second drive roller. The first spring biases the first driven roller toward the first drive roller with a first biasing force (F1). The second spring biases the second driven roller toward the second drive roller with a second biasing force (F2), where F2>F1. The reader is configured to read an image of a medium passing through the junction.

According to another aspect of the disclosure, an image reading apparatus comprises a housing, a separation roller, a set of slidable protrusions, a reader, a first drive roller, a second drive roller, a first driven roller, a second driven roller, a first spring, and a second spring. The housing having a first opening, a second opening, and a third opening. The first opening extends in a first direction. The second opening have a length shorter than a length of the first opening in the first direction. The second opening is formed in a position located at one side of the first opening in the first direction and is offset from the first opening in a second direction, the second direction being perpendicular to the first direction. The housing defines a first conveyance path communicating the first opening and the third opening. The housing further defines a second conveyance path communicating the second opening and the third opening, at least a portion of the second conveyance path being offset from at least a portion of the first conveyance path in the second direction. The separation roller is rotatably supported in the housing. The separation roller is disposed inside the first conveyance path and outside the second conveyance path in the first direction. The set of slidable protrusions is configured to be slidable in the first direction with respect to a center of the separation roller in the first direction. The reader is disposed in the housing and disposed between the separation roller and the third opening in a third direction. The reader is configured to read an image of a medium introduced in at least one of the first opening and the second opening. The third direction is perpendicular to the first direction and the second direction. The first drive roller is disposed between the separation roller and the third opening in the third direction and inside the second conveyance path in the first direction. The second drive roller is disposed between the separation roller and the third opening in the third direction and outside the second conveyance path in the first direction. A distance between a center of the separation roller and the second drive roller is less than a distance between the center of the separation and the first drive roller in the first direction. The first driven roller opposes the first drive roller. The second driven roller opposes the second drive roller. The first spring biases the first driven roller toward the first drive roller with a first biasing force (F1). The second spring biases the second driven roller toward the second drive roller with a second biasing force (F2), where F2>F1.

According to yet another aspect of the disclosure, an image reading apparatus comprises a first housing, a second housing, a separation roller, a set of slidable protrusions, a reader, a first drive roller, a second drive roller, a first driven roller, a second driven roller, a first spring, and a second spring. The first housing comprises a first surface and is configured to be movable between a close position and an open position. The first surface comprises a first portion and a second portion, the first portion is inclined and where the first portion extends from one end of the first surface to a first position and the second portion extends from the first position to other end of the first surface in a first direction. The second housing opposes the first housing when the first housing is in the close position. The second housing comprises a second surface facing and spaced apart from the first surface in a second direction perpendicular to the first direction when the first housing is in the close position. The second housing comprises a third surface and a fourth surface facing and spaced apart from the third surface in the second direction. The third surface and the fourth surface extend in a third direction perpendicular to the first and second directions and have a width (W). The second housing is configured to support the first housing movably. The second surface comprises an third portion and a fourth portion, the third portion is inclined and where the third portion extends from one end of the second surface to a second position and the fourth portion extends from the second position to other end of the second surface in the first direction. The separation roller is rotatably supported in the second housing and is exposed from the third portion of the second surface of the second housing. Each of the set of slidable protrusions is configured to be slidable relative to in conjunction with each other in the third direction with respect to the separation roller. The reader is disposed between the separation roller and the other end of the second surface of the second housing in the first direction. The reader is configured to read an image of a medium when a medium is conveyed between the first surface of the first housing and the second surface of the second housing. The first drive roller is disposed between the separation roller and the other end of the second surface of the second housing in the first direction. The first drive roller is exposed from one of the second portion of the first surface of the first housing and the fourth portion of the second surface of the second housing. The first drive roller is disposed within the width (W) of the third surface and the fourth surface of the second housing. The second drive roller is disposed between the separation roller and the other end of the second surface of the second housing in the first direction. The second drive roller is exposed from the one of the second portion of the first surface of the first housing and the fourth portion of the second surface of the second housing. A distance between a center of the separation roller and the second drive roller is less than a distance between the center of the separation and the first drive roller in the first direction. The second drive roller is disposed outside the width (W) of the third surface and the fourth surface of the second housing. The first driven roller is exposed from the other of the second portion of the first surface of the first housing and the fourth portion of the second surface of the second housing. The first driven roller opposes the first drive roller. The second driven roller is exposed from the other of the second portion of the first surface of the first housing and the fourth portion of the second surface of the second housing. The second driven roller opposes the second drive roller. The first spring biases the first driven roller toward the first drive roller with a first biasing force (F1). The second spring biases the second driven roller toward the second drive roller with a second biasing force (F2), where F2>F1.

According to yet another aspect of the disclosure, an apparatus comprising a housing, a first guide, a second guide, and a first conveyor. The first guide is disposed in the housing and is configured to provide a first path between a first opening and a second opening. The first guide comprises an first portion and a second portion. The first opening extends in a first direction. The second opening extends in the first direction. The second opening is in communication with the first opening. The first portion is inclined and where the first portion of the first guide extends from the first opening to a first position and the second portion of the first guide extends from the first position to the second opening. The second guide is disposed in the housing and is configured to provide a second path between a third opening and a junction. The junction is located where the first path intersects the second path. The third opening is in communication with the second opening and is offset from the first opening in a second direction. The third opening is formed in a position located at one side of the first opening in the first direction. The first conveyor comprises a first drive roller, a second drive, a first driven roller, a second driven roller, a first spring, and a second spring. The first conveyor is in the second portion of the first guide. The first drive roller is disposed inside a path between the third opening and the second opening. The path comprises at least the second path. The first drive roller is offset of a center of the first guide in the first direction. The second drive roller is disposed outside the path between the third opening and the second opening. A distance between the center of the first guide and the second drive roller is less than a distance between the center of the first guide and the first drive roller in first direction. The first driven roller opposes the first drive roller. The second driven roller opposes the second drive roller. The first spring biases the first driven roller toward the first drive roller with a first biasing force (F1). The second spring biases the second driven roller toward the second drive roller with a second biasing force (F2), where F2>F1.

DETAILED DESCRIPTION

In a known image reading apparatus, the first driven roller and the second driven roller are generally biased to the first drive roller and the second drive roller, respectively. Further a known image reading apparatus generally includes a regulation member. When plural media with different widths are introduced in the first introduction opening, the regulation member regulates the media with respect to the center of the first introduction opening in the width direction.

The first drive roller and the first driven roller does not pinch a narrow medium, such as a postcard and a business card, since the first drive roller and the first driven roller are disposed inside the path between the second introduction opening and the discharge opening and the one end side in the width direction. The narrow medium is generally thicker than a wide medium, such as a paper, in a thick direction. Thus, when a conveyance direction of a media, introduced in the first introduction opening, is bended by the bent portion, the narrow width media tends to receive stronger conveying friction than the wide medium. As a result, when plural media with different widths are introduced in the first introduction opening, a convening speed difference may arise between the wide media and the narrow media. The conveying speed difference is a difference of a conveying speed of the wide media from the first introduction opening to the discharge opening through the junction and a conveying speed of the narrow media from the first introduction opening to the discharge opening through the junction.

In order to suppress the conveying speed difference, it may be effective to increase both a bias force to bias the first driven roller to the first drive roller and a bias force to bias the second driven roller to the second drive roller. However, increasing the bias forces may deform the housing because the reaction force of the bias forces affects the housing. Then, it is required to increase stiffness of the housing to prevent deformation. Since reinforcing the housing and/or adopting more rigid materials to increase stiffness of the housing, it may cause growing in size and rising in production cost.

An aspect of the disclosure relates to an image reading apparatus configured to suppress the conveying speed difference between the wide media and the narrow media, when plural media with different width are introduced in the first introduction opening, while suppressing the lack of stiffness of the housing.

An example embodiment is described in detail herein with reference to the accompanying drawings, like reference numerals being used for like corresponding parts in the various drawings.

InFIG. 1, a side of an image reading apparatus1on which a discharge opening13is disposed may be defined as the front side of the image reading apparatus1. For purposes of the description herein, a side of the image reading apparatus1that is placed on the left when viewed from the side facing the discharge opening13is defined as the left side of the image reading apparatus1. To facilitate understanding of the orientation and relationship of the various elements disclosed herein, the front, rear, left, right, up, and down of the image reading apparatus1may be determined with reference to axes of the three-dimensional Cartesian coordinate system included in each of the relevant drawings.

As depicted inFIGS. 1-6, the image reading apparatus1may comprise a housing30and a sheet tray36. The housing30may comprise a first housing31, a second housing32. The first housing31disposed on the upper side of the image reading apparatus1and the second housing32disposed on the lower side of the image reading apparatus1may oppose one another in a vertical direction, e.g., an up-down direction, with a distance therebetween. The second housing32may comprise a first and second side walls33R and33L. The first and second side walls33R and33L may be spaced apart in the left and right direction. The first side wall33R defines a right side surface of the second housing32. The second side wall33L defines a left side surface of the second housing32. The upper end of each of the first and second side walls33R and33L may be disposed to each of the left and right ends of the first housing31, respectively. The lower end of each of the first and second side walls33R and33L may be connected to each of the left and right ends of the second housing32, respectively.

The first housing31and the second housing32may be interposed between the first and second side walls33R and33L.

As depicted inFIGS. 1,5and7, the first housing31may comprise an upper surface31A, a front surface31B, and an upper guide surface31G. The upper surface31A may comprise a flat surface facing upward. The upper surface31A may slantingly extend forwardly and downwardly from its rear side in a slanted manner. A touch panel70may be disposed at a central portion of the upper surface31A. The front surface31B may comprise a flat surface facing forward. The front surface31B may extend vertically downward from the front end of the upper surface31A to a lower end31BA. As depicted inFIGS. 5-7, the upper guide surface31G may comprise a curved surface disposed on a rear portion thereof and a HORIZONTAL surface disposed on a front portion thereof. The curved surface, e.g., an inclined portion, of the upper guide surface31G may extend forwardly and downwardly from a rear end31GA thereof, e.g., the rear end of the lower side of the upper surface31A, in a slanted manner. The flat surface, e.g., a horizontal portion, of the upper guide surface31G may extend forwardly from a central portion of the first housing31in the front-rear direction to the lower end31BA of the front surface31B.

As depicted inFIGS. 1,2and5-8, the second housing32may comprise a front surface32B, a lower guide surface32G and a rear surface32C. The front surface32B may comprise a flat surface facing forward. The front surface32B may comprise an upper end32BA. The upper end32BA may be positioned below the lower end31BA of the front surface31B with a distance therebetween. The front surface32B may extend vertically downward from the upper end32BA. As depicted inFIGS. 5-7, the lower guide surface32G may comprise a curved surface disposed on a rear portion thereof and a HORIZONTAL surface disposed on a front portion thereof. The curved surface, e.g., an inclined portion, of the lower guide surface32G may extend forward and downward, in a slanted manner along the inclined portion of the upper guide surface31G. The flat surface, e.g., a horizontal portion of the lower guide surface32G may extend forward from a central portion of the second housing32in the front-rear direction to the upper end32BA of the front surface32B. The rear surface32C may comprise a flat surface facing rearward. The rear surface32C may extend downward from its upper end in a generally vertical direction.

As depicted inFIGS. 2,6and8, the second housing32may comprise a lower card guide surface32J and an upper card guide surface32H. The lower card guide surface32J may extend horizontally rearward to the rear surface32C from a junction J1(which is described later) of the horizontal portion of the lower guide surface32G. The upper card guide surface32H may be positioned above the lower card guide surface32J with a distance therebetween. The upper card guide surface32H may extend horizontally rearward to the rear surface32C in parallel with the lower card guide surface32J. As depicted inFIG. 6, the height or level of the upper card guide surface32H in the vertical direction may be substantially the same as the height or level of the horizontal portion of the upper guide surface31G in the vertical direction.

The upper guide surface31G, the lower guide surface32G, the upper card guide surface32H, and the lower card guide surface32J might not be limited to a smooth continuous surface, but may be constituted by, for example, tips of ribs or protrusions.

As depicted inFIGS. 4,6and8, a junction J1may be disposed at a position where the lower card guide surface32J may extend to the right end inFIG. 6, e.g., the rear end, of the horizontal portion of the lower guide surface32G.

As depicted in FIGS.1and4-6, the housing30may define a first introduction opening11and a discharge opening13. One or more media (e.g., sheets SH) may be inserted into the first introduction opening11. The sheet SH may comprise a wide sheet and a narrow sheet. The wide sheet may comprise, for example, a sheet of with a letter size or a A4-size. The narrow sheet mat comprise, e.g., a postcard. The sheet SH also may comprise, e.g., a plastic card and a business card, in a case in that the sheet SH is easy to be bended and thin enough to be guided along the upper and lower guide surfaces31G and32G.

In one example, as depicted inFIG. 5, the first introduction opening11may be defined between the first housing31and the second housing32. For example, the first introduction opening11may be defined by a space between the rear edge31GA of the upper guide surface31G and the rear edge32GA of the lower guide surface32G. As depicted inFIG. 1, the first introduction opening11may extend in the left-right direction from a portion near the first side wall33R to a portion near the second side wall33L. In one example, the length of the first introduction opening11in the left-right direction may be longer than the width of the sheet SH.

The left-right direction of the image reading apparatus1may be an example of a width direction. In the example embodiment, one end and an opposite end in the width direction may be examples of a right end and a left end, respectively.

As depicted inFIGS. 1 and 5, the sheet SH may be discharged from the discharge opening13. The discharge opening13may be defined between the first housing31and the second housing32. For example, the discharge opening13may be defined by a space between the lower end31BA of the front surface31B and the upper end32BA of the front surface32B. The discharge opening13may extend in the left-right direction from a portion near the first side wall33R to a portion near the second side wall33L. In one example, the length of the discharge opening13in the left-right direction may be longer than the width of the sheet SH, similar to the first introduction opening11.

As depicted inFIGS. 4-6, the image reading apparatus1may comprise a first guide portion10. The first guide portion10may comprise the upper guide surface31G of the first housing31and the lower guide surface32G of the second housing32in the vertical direction. The first guide portion10may define a first conveyance path P1. The first guide portion10may be configured to guide the sheet SH from the first introduction opening11to the discharge opening13along the first conveyance path P1.

A portion of the first guide portion10may extend frontward and downward from the first introduction opening11in a slanted manner. The first guide portion10may comprise a bent portion BP, in which the first guide portion10bends, in a middle portion of the housing30in the front-rear direction. The first guide portion10may extend horizontally forward from the bent portion BP to the discharge opening13. As depicted inFIGS. 5 and 6, the bent portion BP may comprise a boundary between the inclined portion and the horizontal portion of the upper guide surface31G and a boundary between the inclined portion and the horizontal portion of the lower guide surface32G.

As depicted inFIG. 7, the first housing31may be pivotally attached to the second housing32about a rotation axis X31. The rotation axis X31may extend in the left-right direction at the lower end31BA of the front surface31B of the first housing31. As the first housing31pivotally moves to separate from the second housing32in an upward direction, the first guide portion10may open.

As depicted inFIGS. 2,4,6and7, the housing30may define a second introduction opening12. A narrow medium (e.g., a card CA having a width smaller than that of the sheet SH) may be inserted into the second introduction opening12. The card CA may be a medium having an area smaller than that of the sheet SH. The card CA may be, for example, a business card, an ATM card, a membership card, a license card.

According to one or more arrangements, the second introduction opening12may be provided in the second housing32, as depicted inFIGS. 2,4and6. The second introduction opening12may be disposed at a portion of the rear surface32C on the side of the first side wall33R. The second introduction opening12may extend in the left-right direction. The length of the second introduction opening12in the left-right direction may be shorter than the length of the first introduction opening11in the left-right direction. In one example, the length of the second introduction opening12in the left-right direction may be longer than the width of the card CA. The height of the second introduction opening12in the vertical direction may be almost the same as the height of the horizontal portion of the first guide portion10and the discharge opening13in the vertical direction. The second introduction opening12may be disposed below a right end portion of the first introduction opening11in the vertical direction.

As depicted inFIGS. 3 and 6, the card CA may be discharged from a right end portion of the discharge opening13. For example, the discharge opening13may be shared to discharge the sheet SH inserted through the first introduction opening11and the card CA inserted through the second introduction opening12.

As depicted inFIGS. 4,6and8, the image reading apparatus1may comprise a second guide portion20. The second guide portion20may comprise the upper card guide surface32H and the lower card guide surface32J in vertical direction. That is, the second guide portion20may be provided in the second housing32. The second guide portion20may straightway extend frontward from the second introduction opening12and may join the first guide portion10at the junction J1.

The junction J1may be disposed at a proximal portion of the bent portion BP, e.g., a portion between the inclined portion and the horizontal portion of the upper guide surface31G and the lower guide surface32G.

As depicted inFIG. 4, the card conveyance area includes a portion of the first guide portion. For example, the portion of the first guide portion10on the right side and between the discharge opening and the junction may correspond to a card conveyance area29. The width of card conveyance area29is the same as the width of the second guide portion in the left-right direction. As depicted inFIGS. 4 and 6, the second guide portion20and a right side portion of the first guide portion10where the card conveyance area29may be disposed, may define a second conveyance path P2. The second conveyance path P2extending horizontally from the second introduction opening12disposed on the rear side of the image reading apparatus1to the right end portion of the discharge opening13disposed on the front side of the image reading apparatus1.

The card CA may be guided from the second introduction opening12to the card conveyance area29of the first guide portion10along the second conveyance path P2. Then, the card CA may be guided from the card conveyance area29to the right side portion of the discharge opening13along the second conveyance path P2.

As depicted inFIGS. 1-3, the sheet tray36may comprise a base portion36A, a central portion36B and a tip portion36C. The base portion36A may be pivotally supported by the first and second side walls33R and33L about a rotation axis X36A extending along the left-right direction. The central portion36B may be connected to an end of the base portion36A further from the rotation axis X36A. The tip portion36C may be connected to an end of the central portion36B further from the base portion36A. The central portion36B may have an opening39of a rectangular shape at a central portion thereof.

When the sheet tray36is open as depicted inFIGS. 1,4and5, the base portion36A, the central portion36B and the tip portion36C may extend upward and rearward so as to continue to the inclined portion of the lower guide surface32G. When the sheet tray36is opened, the first introduction opening11may be exposed (e.g., open). When the sheet tray36is opened, surfaces of the base portion36A, the central portion36B and the tip portion36C those facing upward may comprise a supporting surface36H. When one or more sheets SH may be placed on the sheet tray36, the supporting surface36H supports the sheets SH from below.

When the sheet tray36is closed as depicted inFIGS. 2,3and6, the base portion36A may extend vertically and substantially aligned with the rear surface32C of the second housing32. The central portion36B may cover the upper surface31A of the first housing31from above. The tip portion36C may cover the front surface31B of the first housing31from the front side of the front surface31B. As depicted inFIGS. 2 and 3, the opening39may allow the touch panel70to be exposed outside the image reading apparatus1when the sheet tray36is closed.

As depicted inFIGS. 1,5and8, the image reading apparatus1may comprise a pair of regulation members36G. The pair of regulation members36G is separated each other in the left-right direction. The pair of regulation members36G is connected to the base portion36A slidably in the left-right direction. The pair of regulation members36G protrudes upwardly from the supporting surface36H. Each of the pair of regulation members36G engages with a rack and pinion mechanism (not shown) that is disposed inside the base portion36A. When one or more sheets SH may be placed on the sheet tray36and be inserted in the first introduction opening11, each of the pair of regulation members36G regulates the one or more sheets SH in the left-right direction by contacting the outer edges of the one or more sheets SH in the left-right direction. Each of the pair of regulation members36G is interlocked by the rack and pinion mechanism, thereby regulating the one or more sheets SH with respect to the center of the first introduction opening11in the left-right direction (e.g., the sheets SH may be symmetric with respect to the center of the first introduction opening11in the left-right direction).

As depicted inFIG. 1, when the pair of regulation member36G separates each other with the largest separation distance in the left-right direction, each of the pair of regulation members36G may regulate a sheets SH with a letter size, for example, with respect to the center of the first introduction opening11in the left-right direction. As depicted inFIG. 8, when the pair of regulation member36G separates each other with a smaller separation distance with respect to the largest separation distance in the left-right direction, each of the pair of regulation members36G regulates a sheets SH with a postcard size, for example, with respect to the center of the first introduction opening11in the left-right direction. Each of the pair of regulation members36G regulates a sheets SH with a business card size, for example, with respect to the center of the first introduction opening11in the left-right direction, when the pair of regulation members36G become closer with respect to the smaller separation distance in the left-right.

As depicted inFIGS. 4-6, the image reading apparatus1may comprise a control board54, a drive source40M, a conveyor40and a reader55.

As depicted inFIGS. 5 and 6, the control board54may be disposed at a bottom portion of the second housing32. The control board54may be an electronic circuit board comprising a central processing unit (CPU), a read-only memory (ROM), and a random-access memory (“RAM”). Power may be supplied to the control board54from a home electric outlet, via an AC adapter and a power supply cord. The control board54may be electrically connected to, for example, the drive source40M, the reader55, and the touch panel70.

As depicted inFIG. 4, the drive source40M may be disposed in the second housing32at the second side wall33L. The drive source40M may comprise a motor and transmission gears. The drive source40M may be configured to generate the drive force while the drive source40M is controlled by the control board54.

As depicted inFIGS. 4-8, the conveyor40may comprise a separation roller48, a separation pad49, an upstream conveyor portion41, and a downstream conveyor portion42. The reader55may comprise a first reader55A and a second reader55B. In the first guide portion10, the separation roller48and the separation pad49may be followed by the upstream conveyor portion41, the second reader55B, the first reader55A, and the downstream conveyor portion42that may be arranged in this order from the upstream side to the downstream side in a conveyance direction. The sheet SH and the card CA may be conveyed in the conveyance direction from the first introduction opening11and the second introduction opening12, respectively, toward the discharge opening13. The separation roller48and the separation pad49may be disposed between the first introduction opening11and the junction J1. The upstream conveyor portion41, the second reader55B, the first reader55A and the downstream conveyor portion42may be disposed between the discharge opening13and the junction J1.

As depicted inFIGS. 4,5and8, the separation roller48may be rotatably supported in the second housing32. An upper portion of the separation roller48may be exposed from the inclined portion of the lower guide surface32G toward the first guide portion10. Since the first guide portion defines the first conveyance path P1, the separation roller48can be understood to be exposed from the inclined portion of the lower guide surface32G toward the first conveyance path P1. The separation roller48may be disposed at a central portion of the first guide portion10in the left-right direction. The central portion may be defines as a certain area that includes the center of the first guide portion10in the left-right direction. The certain area may be an area close to the center of the first guide portion10with respect to the card conveyance area29.

The separation roller48may be configured to be driven by the drive source40M. The control board54may be configured to control the drive source40M. The separation roller48may be configured to rotate while making contact with the sheets SH placed on the sheet tray36to feed the sheets SH to the first guide portion10.

As depicted inFIGS. 5 and 7, the separation pad49may be disposed at the first housing31. The separation pad49may be exposed to the first guide portion10in the upper guide surface31G. The separation pad49may comprise a friction member, e.g., rubber and elastomer, having a plate shape. The separation pad49may be biased by an biasing member (not depicted) so that the separation pad49may be biased against the separation roller48when the first housing31is closed. The separation roller48and the separation pad49may be configured to separate the sheets SH to be conveyed in the first guide portion10one by one while nipping the sheets SH therebetween.

As depicted inFIGS. 4-8, the upstream conveyor portion41may be disposed between the junction J1and the second reader55B. The upstream conveyor portion41may comprise third drive rollers131,132and a card drive roller151.

The third drive rollers131,132and the card drive roller151may be disposed in the second housing32. The third drive rollers131,132and the card drive roller151may be connected to an upstream drive shaft41S. The upstream drive shaft41S may extend from the drive source40M to a portion near the first side wall33R in the left-right direction. The card drive roller151may be disposed at a right end portion of the first guide portion10and inside the second conveyance path P2. A distance between the third drive rollers131,132and the center of the second housing32in the left-right direction is shorter than a distance between the card drive roller151and the center of the second housing32in the left-right direction. The third drive rollers131,132are disposed outside the second conveyance path P2. The third drive roller131is disposed at left side of the separation roller48. The third drive roller132is disposed at right side of the separation roller48. The third drive rollers131,132and a card drive roller151are configured to rotate by a drive force of the drive source40M. The drive force is transmitted by the upstream drive shaft41S.

As depicted inFIG. 8, the upstream conveyor portion41may comprise third driven rollers135and136, third biasing members138and139, and a card driven roller155.

The third driven rollers135and136may be disposed in the first housing31. The third driven rollers135and136may be rotatably connected to third driven shaft134. As depicted inFIGS. 5,8and9, the third driven shaft134may be disposed above the upstream drive shaft41S and extend in the left-right direction. The left end of the third driven shaft134may extend left side of the left end of the third drive roller131in the left-right direction. The right end of the third driven shaft134may extend right side of the right end of the third drive roller132in the left-right direction. The third driven roller135may be disposed above the third drive roller131. The third driven roller135may contact with the third drive roller131when the first housing31is closed. The third driven136may be disposed above the third drive roller132. The third driven roller136may contact with the third drive roller132when the first housing31is closed.

As depicted inFIGS. 8 and 9, the third biasing members138and139may be disposed in the first housing31. The third biasing members138and139may be disposed above the third driven shaft134. The third biasing members138and139may be, e.g., coiled springs. The third biasing member138may be bias a left end portion of the third driven shaft134toward the upstream drive shaft41S with a third biasing force F3. The third biasing member139may be bias a right end portion of the third driven shaft134toward the upstream drive shaft41S with the third biasing force F3. In other words, the third biasing members138and139may bias the third driven rollers135and136toward the third drive rollers131and132with the third biasing force F3, respectively. The third driven rollers135and136may be biased toward the third drive rollers131and132by the third biasing force F3. The third drive rollers131,132and the third driven rollers135,136may nip a sheet SH guided by the first guide portion, thereby transmitting a conveying force.

As depicted inFIGS. 6-8, the card driven roller155may be supported rotatably by the first housing131. A portion of the card driven roller155may be exposed from the upper guide surface31G. The card driven roller155may face and be spaced apart from the card drive roller151in the up-down direction. When a sheet SH, which is wide enough to extend to the second conveyance path P2(e.g., a paper with the A4-size or the letter size), is guided along the first guide portion10, the sheet SH passes through a gap between the card drive roller151and the card driven roller155without being nipped by the card drive roller151and the card driven roller155. On the other hand, when a card CA is guided along the first guide portion10via the second guide portion20, the card CA passes through a gap between the card drive roller151and the card driven roller155with being nipped by the card drive roller151and the card driven roller155. The card CA receives a feeding force from the card drive roller151and the card driven roller155.

As depicted inFIG. 6, a card aid roller156may be disposed in the upper card guide surface32H of the second guide20. The card aid roller156may bias a card CA, which is inserted in the second introduction opening12, toward the lower card guide surface32J.

The second reader55B may be attached to the second housing32. For example, the second reader55B may comprise a contact image sensor (“CIS”), a CIS holder and a contact glass. The upper surface of the second reader55B may be exposed to the first guide portion10at the horizontal portion of the lower guide surface32G.

The first reader55A may be attached to the first housing31. For example, the first reader55A may comprise a contact image sensor (“CIS”), a CIS holder and a contact glass. The lower surface of the first reader55A may be exposed to the first guide portion10at the horizontal portion of the upper guide surface31G. The first reader55A may be disposed closer to the discharge opening13than the second reader55B.

In one or more examples, the first reader55A and the second reader55B may be disposed across an entire length of the first guide portion10. The first reader55A and the second reader55B may be disposed opposite to each other in the vertical direction to interpose the first guide portion10.

The first reader55A and the second reader55B may be configured to read an image on each side of the sheet SH when the sheet SH is conveyed in the first guide portion10. The first reader55A and the second reader55B may also be configured to read an image on each side of the card CA when the card CA guided by the second guide portion20is conveyed in the card conveyance area29.

As depicted inFIGS. 4-8and9, the downstream conveyor portion42may be disposed between the first reader55A and the discharge opening13in the front-rear direction. The downstream conveyor portion42may comprise a first drive roller111, second drive rollers121and122, and a fourth drive roller141. The first drive roller111, the second drive rollers121and122, and the fourth drive roller141may be disposed in the second housing32. The first drive roller111, the second drive rollers121and122, and the fourth drive roller141may be fixed in a downstream drive shaft42S. The downstream drive shaft42S may extend from the drive source40M to a portion near the first side wall33R in the left-right direction. The first drive roller111may be disposed in the right end portion of the first guide portion10, i.e., inside the second conveyance path P2. The second drive rollers121and122may be disposed in center side of the first guide portion10with respect to the first drive roller111in the left-right direction. In other words, a distance between a center of the second housing32and the second drive rollers121and122in the left-right direction may be shorter than a distance between the center of the second housing32and the first drive roller111. As depicted inFIG. 4, the second drive rollers121and122may be disposed outside the second conveyance path P2in the left-right direction. The second drive rollers122may be disposed in a right side of the separation roller48. The second drive rollers121may be disposed in a left side of the separation roller48. The fourth drive roller141may be disposed in a left side of the second drive rollers122. That is, the fourth drive roller141may be disposed in a left end portion of the first guide portion10. The second drive rollers121and122may be interposed between the first drive roller111and the fourth drive roller141. The first drive roller111, the second drive rollers121and122, and the fourth drive roller141may be rotated by a drive force transmitted from the drive source40M via the downstream drive shaft42S.

As depicted inFIGS. 4-8and9, the downstream conveyor portion42may also comprise a first driven roller115, second driven rollers125and126, a fourth driven roller145, first biasing members118and119, second biasing members128and129and fourth biasing members148and149.

The first driven roller115may be disposed in the first housing31. The first driven roller115may be supported rotatably by a first driven shaft114. As depicted inFIGS. 6,8and9B, the first driven shaft114may be disposed in an upper side of the downstream drive shaft42S. The first driven shaft114may extend from a left side of a left side surface of the first drive roller111to a right side of a right side surface of the first drive roller111in the left-right direction. The first driven roller115may be disposed in an upper side of the first drive roller111. The first driven roller115may contact the first drive roller111when the first housing31is closed.

As depicted inFIGS. 5,7,8and9B, the second driven rollers125and126may be disposed in the first housing31. The second driven rollers125and126may be supported rotatably by a second driven shaft124. The second driven shaft124may be disposed in an upper side of the downstream drive shaft42S. The second driven shaft124may extend from a left side of a left side surface of the second drive roller121to a right side of a right side surface of the second drive roller122in the left-right direction. The second driven roller125may be disposed in an upper side of the second drive roller121. The second driven roller125may contact the second drive roller121when the first housing31is closed. The second driven roller126may contact the second drive roller122when the first housing31is closed.

As depicted inFIGS. 7,8and9B, the fourth driven roller145may be disposed in the first housing31. The fourth driven roller145may be supported rotatably by a fourth driven shaft144. The fourth driven shaft144may be disposed in an upper side of the downstream drive shaft42S. The fourth driven shaft144may extend from a left side of a left side surface of the fourth drive roller141to a right side of a right side surface of the fourth drive roller141in the left-right direction. The fourth driven roller145may be disposed in an upper side of the fourth drive roller141. The fourth driven roller145may contact the fourth drive roller141when the first housing31is closed.

As depicted inFIGS. 8 and 9B, the first biasing members118and119may be, e.g., coiled springs. The first biasing member118and119may be disposed in the first housing31. The first biasing member118and119may be disposed in an upper side of the first driven shaft114. The first biasing member118may bias a left end portion of the first driven shaft114toward the downstream drive shaft42S with a biasing force F118. The first biasing member119may bias a right end portion of the first driven shaft114toward the downstream drive shaft42S with a biasing force F119. A first biasing force F1is a resultant force of the biasing force F118and the biasing force F119. In other word, the first biasing members118and119may bias the first driven roller115toward the first drive roller111with the first biasing force F1. By virtue of the first biasing force F1, the first drive roller111and the first driven roller115may nip a left side of a sheet SH to transmit the driving force, when the sheet SH, which is wide enough to extend to the second conveyance path P2, is guided along the first guide portion10.

The second biasing members128and129may be, e.g., coiled springs. The second biasing members128and129may be disposed in the first housing31. The second biasing members128and129may be disposed in an upper side of the second driven shaft124. The second biasing member128may bias a left end portion of the second driven shaft124toward the downstream drive shaft42S with a second biasing force F2. The second biasing member129may bias a right end portion of the second driven shaft124toward the downstream drive shaft42S with the second biasing force F2. In other word, the second biasing member128may bias the second driven roller125toward the second drive roller121with the second biasing force F2, and the second biasing member129may bias the second driven roller126toward the second drive roller122with the second biasing force F2. By virtue of the second biasing force F2, the second drive rollers121and122and the second driven rollers125and126may nip a sheet SH to transmit the driving force, when the sheet SH is guided along the first guide portion10.

The fourth biasing members148and149may be, e.g., coiled springs. The fourth biasing members148and149may be disposed in the first housing31. The fourth biasing members148and149may be disposed in an upper side of the fourth driven shaft144. The fourth biasing member148may bias a left end portion of the fourth driven shaft144toward the downstream drive shaft42S with a biasing force F148. The fourth biasing member149may bias a right end portion of the fourth driven shaft144toward the downstream drive shaft42S with a biasing force F149. A fourth biasing force F4is a resultant force of the biasing force F148and the biasing force F149. In other word, the fourth biasing members148and149may bias the fourth driven roller145toward the fourth drive roller141with the fourth biasing force F4. By virtue of the fourth biasing force F4, the fourth drive roller141and the fourth driven roller145, which are disposed in an opposite side with respect to the first drive roller111and the first driven roller115in the left-right direction, may nip a right side of a sheet SH to transmit the driving force, when the sheet SH, which is wide enough to extend to the second conveyance path P2, is guided along the first guide portion10.

The first biasing force F1, the second biasing force F2, the third biasing force F3and the force biasing force F4may be set to satisfy the following magnitude relationship. The second biasing force F2may be greater than the first biasing force F1. For example, the second biasing force F2may be equal to or greater than 1.2 times the first biasing force F1. Further, the second biasing force F2may be equal to or less than 1.8 times the first biasing force F1. The magnitude relationship between the first biasing force F1and the second biasing force F2may be set on the basis of a result of experiments conducted by the inventor (see e.g.,FIG. 10which is described later). The third biasing force F3may be equal to the second biasing force F2. The fourth biasing force F4may be equal to the first biasing force F1. Note that the term of “equal to” include tolerance in production.

In this disclosure, the biasing forces F118and F119may be 250 gram-force (gf), and the first biasing force F1, which is the resultant force of the biasing forces F118and F119, may be 500 gf, for example. The second biasing force F2and the third biasing force F3may be equal to or greater than 750 gf, which is 1.5 times greater than the first biasing force F1. The biasing forces F148and F149may be 250 gf, and the first biasing force F4, which is the resultant force of the biasing forces F148and F149, may be 500 gf.

As depicted inFIGS. 1 and 5, the touch panel70may be attached to an interior of the first housing31on the upper surface31A side. The touch panel70may be exposed outside the first housing31through a rectangular-shaped touch panel opening31H that may be provided in the upper surface31A. The touch panel70may comprise a liquid crystal display panel, a light source, e.g., fluorescent lamp or a light-emitting diode (LED), configured to irradiate the liquid crystal display panel with light from the back side of the liquid crystal display panel, and a contact sensing film attached to a surface of the liquid crystal display panel.

The touch panel70may be configured to display an operational status of the image reading apparatus1, e.g., a processing status of an image reading operation and errors, and various buttons, e.g., buttons to start an image reading operation and to make settings, under the control of the control board54. The touch panel70may be configured to permit an external input. When a button displayed in the touch panel70is touched (e.g., selected) to perform an operation or setting corresponding to the button, the touch panel70may transmit a signal in response to the touch operation, to the control board54.

The image reading apparatus1may be configured to read an image on the sheet SH and the card CA.

When an image on the sheet SH is read, the sheet tray36may be open, as depicted inFIGS. 1 and 5. One or more sheets SH may be placed on the sheet tray36. When the control board54receives an instruction to read an image on the sheet SH from the touch panel70, the control board54may refer to the detection result of a sheet detection sensor (not shown). When the control board54determine that at least one sheet SH placed on the sheet tray36is held or nipped between the separation roller48and the separation pad49based on the detection result of the sheet detection sensor, the control board54may start the operation of reading an image on the sheet SH.

The control board54may send an instruction to generate the drive force to the drive source40M. In response to the instruction, the separation roller48may be first rotated while holding the sheet SH together with the separation pad49. The separation roller48may introduce the sheet SH placed on the sheet tray36through the first introduction opening11and feed the sheet SH to the first guide portion10. At this time, the sheets SH may be separated one by one due to frictional force between the separation pad49and the sheet SH.

Thereafter, the third drive rollers131and132and the third driven rollers135and136, which are a portion of the upstream conveyor portion41, may convey the sheet SH fed by the separation roller48in the first guide portion10. The first reader55A and the second reader55B may be read an image on each side of the sheet SH being conveyed in the first guide portion10. The first drive roller111, the second drive rollers121and122, the fourth drive roller141, the first driven roller115, the second driven rollers125and126and the fourth driven roller145, which are a portion of the downstream conveyor portion42, may discharge the sheet SH whose image has been read, outside the housing30through the discharge opening13.

When an image on the card CA is read, the sheet tray36may be closed, as depicted inFIGS. 2,3and6. When the sheet tray36is closed, the card CA may be inserted into the second introduction opening12from the rear side of the housing30, as depicted inFIG. 2. Thereafter, the card CA may pass through the second guide portion20. The leading end of the card CA may reach the card conveyance area29. When the control board54receives an instruction to read an image on the card CA from the touch panel70, the control board54may refer to the detection result of a card detection sensor (not shown). When the control board54may determine that the card CA inserted from the second introduction opening12passes the second guide portion20, and the leading end of the card CA reaches the card conveyance area29based on the detection result of the card detection sensor, the control board54may start the operation of reading an image on the card CA.

The control board54may be configured to send an instruction to generate the drive force to the drive source40M. The card drive roller151of the upstream conveyor portion41may convey the card CA in the card conveyance area29. The first reader55A and the second reader55B may read an image on each side of the card CA being conveyed in the card conveyance area29. As depicted inFIG. 3, the first drive roller111and the first driven roller115, which are a portion of the upstream conveyor portion41,42may discharge the card CA whose image has been read, outside the housing30through the discharge opening13.

In the image reading apparatus1of this disclosure, the second biasing force F2of the second biasing members128and129may be greater than the first biasing force F1of the first biasing members118and119. For example, the second biasing force F2may be greater than or equal to 1.2 times the first biasing force F1and less than or equal to 1.8 times the first biasing force F1, thereby the second drive rollers121and122and the second driven rollers125and126may nip a sheet SH stronger than the first drive roller111and the first driven roller115. Since the second drive rollers121and122and the second driven rollers125and126may be close to a center of the first guide portion10in the left-right direction, slipping between a sheet SH, which is narrow enough not to be nipped by the first drive roller111and the first driven roller115such as a postcard and business card, and the second drive rollers121and122may be prevented. Therefore, in the image reading apparatus1, it is possible to suppress the convening speed difference between the wide media and the narrow media, when plural media with different width are introduced in the first introduction opening.

InFIG. 10, the horizontal axis indicates a nip load in ratio of the second biasing force F2to the first biasing force F1. The vertical axis indicates a sub-scanning magnitude. The sub-scanning magnitude a variation of a length (in percent) of an image of a sheet SH read by the reader55in the conveyance direction with respect to the actual size of the sheet SH in the conveyance direction.

The broken line L1indicates a relationship between the nip load and the sub-scanning magnitude when a business card with a thickness of 0.2 mm, which is an example of a sheet SH, is fed by the conveyor40. The broken line L2indicates a relationship between the nip load and the sub-scanning magnitude when a postcard with a thickness of 0.2 mm, which is another example of a sheet SH, is fed by the conveyor40. The broken line L3indicates a relationship between the nip load and the sub-scanning magnitude when a business card with a thickness of 0.3 mm, which is yet another example of a sheet SH, is fed by the conveyor40.

As shown by the broken lines L1, L2and L3, when the second biasing force F2is equal to the first biasing force F1, the sub-scanning magnitude corresponds to 4-9%, indicating that the image read by the reader55is extended in the conveyance direction than actual. When the second biasing force F2is greater than the first biasing force F1, the sub-scanning magnitude decreases as the second biasing force increases. The sub-scanning magnitude is small enough to satisfy an acceptable quality level when the second biasing force is greater than or equal to 1.2 times the first biasing force. The sub-scanning magnitude is substantial constant when the second biasing force is greater than 1.8 times the first biasing force. Based on this experimental result, it is clearly shown than slipping between a sheet SH, which is narrow enough not to be nipped by the first drive roller111and the first driven roller115such as a postcard and business card, and the second drive rollers121and122may be prevented.

The first biasing force F1does not increase like the second biasing force F2, the stiffness of the housing may be rigid enough even if the reaction force corresponding to the increase of the second biasing force F2affects the housing. In the image reading apparatus1, since the first housing31may be supported by the second housing32at both end portions, interposing the discharge opening13, in the left right direction, the center of the first housing31in the left-right direction may be deformed by the reaction force of the first biasing force F1and the second biasing force F2. In the image reading apparatus1, since the first biasing force F1is less than the second biasing force F2, the lack of stiffness of the first housing31may be suppressed.

Therefore, in the image reading apparatus1, it is possible to suppress the convening speed difference between the wide media and the narrow media, when plural media with different width are introduced in the first introduction opening11, while suppressing the lack of the stiffness of the housing30.

Further, since the third biasing members138and139may bias the third driven rollers135and136toward the third drive rollers131and132with the third biasing force F3, which may be equal to the second biasing force F2, slipping between a sheet SH, which is narrow enough not to be nipped by the first drive roller111and the first driven roller115, and the third drive rollers131and132may be prevented. Therefore, it is more robustly possible to suppress the convening speed difference between the wide media and the narrow media, when plural media with different width are introduced in the first introduction opening11.

Further, in the image reading apparatus1, since the first drive roller111and the first driven roller115in the right end portion of the first guide portion10may be paired with the fourth drive roller141and the fourth driven roller145in the left end portion of the first guide portion10to convey a wide sheet SH introduced in the introduction opening11, the sheet SH is prevent from skewing.

While the disclosure has been described in detail with reference to the specific embodiment thereof, this is merely an example, and various changes, arrangements and modifications may be applied therein without departing from the spirit and scope of the disclosure.